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Sample records for agn unification model

  1. The Universal Unification Model of AGN

    NASA Astrophysics Data System (ADS)

    Vilkoviskij, E. Y.

    1998-12-01

    It is shown, that the model calculations of the absorption line profiles are possible in the framework of a common model both for BAL QSOs and the Seyfert galaxies with BAL. We suppose that in both cases the BAL-clouds move in the space between two conic surface, starting in the internal surface of the absorbing torus. We argue that the common nature of the intrinsic line absorption in these objects can be explained in an universal unified AGN model, where BAL AGNs are objects intermediate between AGN1 and AGN2

  2. Testing the AGN unification model in the infrared. First results with GTC/CanariCam

    NASA Astrophysics Data System (ADS)

    Ramos Almeida, C.

    2015-05-01

    The unified model for Active Galactic Nuclei (AGN) accounts for a variety of observational differences in terms of viewing geometry alone. However, from the fitting of high spatial resolution infrared (IR) data with clumpy torus models, it has been hinted that the immediate dusty surroundings of Type-1 and 2 Seyfert nuclei might be intrinsically different in terms of covering factor (torus width and number of clouds). Moreover, these torus covering factors also showed variations among objects belonging to the same type, in contradiction with simple unification. Interestingly, these intrinsic differences in Seyfert tori could explain, for example, the lack of broad optical lines in the polarized spectra of about half of the brightest Seyfert 2 galaxies. On the other hand, recent IR interferometry studies have revealed that, in at least four Seyfert galaxies, the mid-IR emission is elongated in the polar direction. These results are difficult to reconcile with unified models, which claim that the bulk of the mid-IR emission comes from the torus. In this invited contribution I summarize the latest results on high angular resolution IR studies of AGN, which constitute a crucial test for AGN unification. These results include those from the mid-infrared instrument CanariCam on the 10.4 m Gran Telescopio CANARIAS (GTC), which are starting to be published by the CanariCam AGN team, Los Piratas (https://sites.google.com/site/piratasrelatedpublications).

  3. Accretion Rate: An Axis Of Agn Unification

    NASA Astrophysics Data System (ADS)

    Trump, Jonathan R.; Impey, C. D.; Kelly, B. C.

    2011-01-01

    We show how accretion rate governs the physical properties of broad-line, narrow-line, and lineless active galactic nuclei (AGNs). We avoid the systematic errors plaguing previous studies of AGN accretion rate by using accurate accretion luminosities from well-sampled multiwavelength SEDs from the Cosmic Evolution Survey (COSMOS), and accurate black hole masses derived from virial scaling relations (for broad-line AGNs) or host-AGN relations (for narrow-line and lineless AGNs). In general, broad emission lines are present only at the highest accretion rates (L/L_Edd>0.01), and these rapidly accreting AGNs are observed as broad-line AGNs or possibly as obscured narrow-line AGNs. Narrow-line and lineless AGNs at lower specific accretion rates (L/L_Edd<0.01) are unobscured and yet lack a broad line region. The disappearance of the broad emission lines is caused by an expanding radiatively inefficient accretion flow (RIAF) at the inner radius of the accretion disk. The presence of the RIAF also drives L/L_Edd<0.01 narrow-line and lineless AGNs to be 10-100 times more radio-luminous than broad-line AGNs, since the unbound nature of the RIAF means it is easier to form a radio outflow. The IR torus signature also tends to become weaker or disappear from L/L_Edd<0.01 AGNs, although there may be additional mid-IR synchrotron emission associated with the RIAF. Together these results suggest that specific accretion rate is an important physical "axis" of AGN unification, described by a simple model.

  4. Probing AGN Unification with galaxy neighbours: pitfalls and prospects

    NASA Astrophysics Data System (ADS)

    Villarroel, B.

    2015-09-01

    Statistical tests of AGN unification harbour many caveats. One way of constraining the validity of the AGN unification is through studies of close neighbours to Type-1 and Type-2 AGN. Examining thousands of AGN- galaxy pairs from the Sloan Digital Sky Survey Data Release 7 and the Galaxy Zoo project, we found that Type-2 AGN appear to reside in more star-forming environments than Type-1 AGN.

  5. X-Ray Absorption, Nuclear Infrared Emission, and Dust Covering Factors of AGNs: Testing Unification Schemes

    NASA Astrophysics Data System (ADS)

    Mateos, S.; Carrera, F. J.; Alonso-Herrero, A.; Hernán-Caballero, A.; Barcons, X.; Asensio Ramos, A.; Watson, M. G.; Blain, A.; Caccianiga, A.; Ballo, L.; Braito, V.; Ramos Almeida, C.

    2016-03-01

    We present the distributions of the geometrical covering factors of the dusty tori (f2) of active galactic nuclei (AGNs) using an X-ray selected complete sample of 227 AGNs drawn from the Bright Ultra-hard XMM-Newton Survey. The AGNs have z from 0.05 to 1.7, 2-10 keV luminosities between 1042 and 1046 erg s-1, and Compton-thin X-ray absorption. Employing data from UKIDSS, 2MASS, and the Wide-field Infrared Survey Explorer in a previous work, we determined the rest-frame 1-20 μm continuum emission from the torus, which we model here with the clumpy torus models of Nenkova et al. Optically classified type 1 and type 2 AGNs are intrinsically different, with type 2 AGNs having, on average, tori with higher f2 than type 1 AGNs. Nevertheless, ˜20% of type 1 AGNs have tori with large covering factors, while ˜23%-28% of type 2 AGNs have tori with small covering factors. Low f2 are preferred at high AGN luminosities, as postulated by simple receding torus models, although for type 2 AGNs the effect is certainly small. f2 increases with the X-ray column density, which implies that dust extinction and X-ray absorption take place in material that share an overall geometry and most likely belong to the same structure, the putative torus. Based on our results, the viewing angle, AGN luminosity, and also f2 determine the optical appearance of an AGN and control the shape of the rest-frame ˜1-20 μm nuclear continuum emission. Thus, the torus geometrical covering factor is a key ingredient of unification schemes.

  6. X-RAY ABSORPTION, NUCLEAR INFRARED EMISSION, AND DUST COVERING FACTORS OF AGNs: TESTING UNIFICATION SCHEMES

    SciTech Connect

    Mateos, S.; Carrera, F. J.; Alonso-Herrero, A.; Hernán-Caballero, A.; Barcons, X.; Ramos, A. Asensio; Almeida, C. Ramos; Watson, M. G.; Blain, A.; Caccianiga, A.; Ballo, L.; Braito, V.

    2016-03-10

    We present the distributions of the geometrical covering factors of the dusty tori (f{sub 2}) of active galactic nuclei (AGNs) using an X-ray selected complete sample of 227 AGNs drawn from the Bright Ultra-hard XMM-Newton Survey. The AGNs have z from 0.05 to 1.7, 2–10 keV luminosities between 10{sup 42} and 10{sup 46} erg s{sup −1}, and Compton-thin X-ray absorption. Employing data from UKIDSS, 2MASS, and the Wide-field Infrared Survey Explorer in a previous work, we determined the rest-frame 1–20 μm continuum emission from the torus, which we model here with the clumpy torus models of Nenkova et al. Optically classified type 1 and type 2 AGNs are intrinsically different, with type 2 AGNs having, on average, tori with higher f{sub 2} than type 1 AGNs. Nevertheless, ∼20% of type 1 AGNs have tori with large covering factors, while ∼23%–28% of type 2 AGNs have tori with small covering factors. Low f{sub 2} are preferred at high AGN luminosities, as postulated by simple receding torus models, although for type 2 AGNs the effect is certainly small. f{sub 2} increases with the X-ray column density, which implies that dust extinction and X-ray absorption take place in material that share an overall geometry and most likely belong to the same structure, the putative torus. Based on our results, the viewing angle, AGN luminosity, and also f{sub 2} determine the optical appearance of an AGN and control the shape of the rest-frame ∼1–20 μm nuclear continuum emission. Thus, the torus geometrical covering factor is a key ingredient of unification schemes.

  7. TORUS2015: The AGN unification scheme after 30 years

    NASA Astrophysics Data System (ADS)

    Gandhi, P.; Hoenig, S. F.

    2015-09-01

    The torus paradigm has proved to be remarkably successful at unifying the observed zoo of active galaxy (AGN) classes, despite having many manifest holes. The field is still data-driven with novel observational results at multiple wavelengths emerging rapidly. We are only now beginning to map out the structure of dusty gas feeding and obscuring AGN, and to model its evolution in galaxy growth. But these have also brought out several apparently contradictory results which must hold the key to future progress. As we celebrate 30 years of the paradigm, this is the perfect time to draw together our current knowledge and reassess the state of the field. This will be an international workshop at the University of Southampton, UK, with the objective of laying out the major challenges to the field and paving future research directions. Our hope is to facilitate plenty of informal discussions between multiwavelength observers and theorists, addressing some key issues: * What is the main driver in the unification scheme? What are the roles of orientation, mass accretion rate and feedback? * What is the nature and structure of gas and dust in the torus? Do we have a self-consistent picture across multiple wavelengths? * How critical is the role of the torus as an interface between small nuclear scales and large galactic scales? Does galaxy evolution necessarily require tori? * How close are we to self-consistently simulating nuclear activity including AGN feeding and nuclear star-formation? Workshop Rationale The three themes of accretion, orientation, and evolution will be covered through invited and solicited contributions. Different to other conferences, we are building each session around some key papers that have shaped the field or those with great future potential to do so. We specifically pit competing ideas against each other to help painting a realistic picture of the state-of-the-art. Each session will end with discussion rounds delving into important future

  8. Testing Unification Models in Dual Active Galactic Nuclei

    NASA Astrophysics Data System (ADS)

    Muller-Sanchez, Francisco

    Dual active galactic nuclei (AGNs), which are kpc-scale separation AGN pairs in galaxy mergers, are ideal targets for testing unification models and models of galaxy evolution. By definition, the AGN nature of the two nuclei suggests that they must be consistent with standard unification models (i.e, a dusty torus obscures the central engine in type 2 AGN). At the same time, they are the result of merger-induced nuclear activity. Galaxy evolution models suggest that merger-induced AGNs are heavily obscured for long periods by the high gas densities powering them. Eventually, feedback drives away material, creating a brief window in time in which the AGN is not obscured. Therefore, in these models, there is no need for a small-scale torus. We are constructing for the first time the spectral energy distributions (SEDs) of the two AGNs in dual AGN systems using data from Hubble and Chandra telescopes, in combination with VLA, Keck and VLT data. However, a critical missing component is dust emission at 30-40 microns, which can only be achieved by SOFIA. We propose FORCAST 31.5 and 37.1 microns observations of the complete sample of 5 confirmed dual AGNs with angular separations >3.5". As suggested by current models, the best wavelength to detect thermal emission from a torus would be between 30-40 microns, where both the non-thermal core and the stellar emission sharply decline, and the torus emission peaks. Thus, FORCAST provides 1) the best angular resolution between 30-40 microns of the current suite of instruments, crucial to separate the emission from the two AGNs, and 2) the largest constraining power for torus models, crucial to characterize the properties of the torus in AGNs.

  9. Unification of Low Luminosity AGN and Hard State X-ray Binaries

    NASA Astrophysics Data System (ADS)

    Connolly, S.

    2015-09-01

    We present X-ray spectral variability of four low accretion rate and low luminosity AGN (LLAGN)- M81, NGC 1097, NGC 1052 and NGC 3998 - as observed by Swift and RXTE. All four objects were selected due to having spectra which hardened with increasing count rate, converse to the 'softer when brighter' behaviour normally observed in AGN with higher accretion rates. The spectra were summed in flux bins and fitted with a variety of models. A simple absorbed power law model was found to fit the spectra of M81, NGC 1097 and NGC 3998 well, whilst NGC 1052 required a partially covered power law model. In all four cases, the most likely cause of spectral variability is found to be hardening of the photon index of the power law component with increasing luminosity. Such a correlation has been seen previously within samples of low accretion rate AGN but in only one case has it been seen within observations of a single AGN. Here we show that such behaviour may be very common in LLAGN. A similar anticorrelation is found in X-ray binary systems in the 'hard state', at low accretion rates similar to those of the LLAGN discussed here. Our observations thus imply that LLAGN are the active galaxy equivalent of hard state X-ray binaries.

  10. AGN Luminosity and Stellar Age: Two Missing Ingredients for AGN Unification as Seen with iPTF Supernovae

    NASA Astrophysics Data System (ADS)

    Villarroel, Beatriz; Nyholm, Anders; Karlsson, Torgny; Comerón, Sébastien; Korn, Andreas J.; Sollerman, Jesper; Zackrisson, Erik

    2017-03-01

    Active galactic nuclei (AGNs) are extremely powerful cosmic objects, driven by accretion of hot gas upon super-massive black holes. The zoo of AGN classes is divided into two major groups, with Type-1 AGNs displaying broad Balmer emission lines and Type-2 narrow ones. For a long time it was believed that a Type-2 AGN is a Type-1 AGN viewed through a dusty kiloparsec-sized torus, but an emerging body of observations suggests more than just the viewing angle matters. Here we report significant differences in supernova (SN) counts and classes in the first study to date of SNe near Type-1 and Type-2 AGN host galaxies, using data from the intermediate Palomar Transient Factory, the Sloan Digital Sky Survey Data Release 7, and Galaxy Zoo. We detect many more SNe in Type-2 AGN hosts (size of effect ∼5.1σ) compared to Type-1 hosts, which shows that the two classes of AGN are located inside host galaxies with different properties. In addition, Type-1 and Type-2 AGNs that are dominated by star formation according to Wide-field Infrared Survey Explorer colors {m}W1-{m}W2< 0.5 and are matched in 22 μm absolute magnitude differ by a factor of ten in L[O iii] λ5007 luminosity, suggesting that when residing in similar types of host galaxies Type-1 AGNs are much more luminous. Our results demonstrate two more factors that play an important role in completing the current picture: the age of stellar populations and the AGN luminosity. This has immediate consequences for understanding the many AGN classes and galaxy evolution.

  11. Non-thermal AGN models

    SciTech Connect

    Band, D.L.

    1986-12-01

    The infrared, optical and x-ray continua from radio quiet active galactic nuclei (AGN) are explained by a compact non-thermal source surrounding a thermal ultraviolet emitter, presumably the accretion disk around a supermassive black hole. The ultraviolet source is observed as the ''big blue bump.'' The flat (..cap alpha.. approx. = .7) hard x-ray spectrum results from the scattering of thermal ultraviolet photons by the flat, low energy end of an electron distribution ''broken'' by Compton losses; the infrared through soft x-ray continuum is the synchrotron radiation of the steep, high energy end of the electron distribution. Quantitative fits to specific AGN result in models which satisfy the variability constraints but require electron (re)acceleration throughout the source. 11 refs., 1 fig.

  12. Unification of gauge couplings in radiative neutrino mass models

    NASA Astrophysics Data System (ADS)

    Hagedorn, Claudia; Ohlsson, Tommy; Riad, Stella; Schmidt, Michael A.

    2016-09-01

    We investigate the possibility of gauge coupling unification in various radiative neutrino mass models, which generate neutrino masses at one- and/or two-loop level. Renormalization group running of gauge couplings is performed analytically and numerically at one- and two-loop order, respectively. We study three representative classes of radiative neutrino mass models: (I) minimal ultraviolet completions of the dimension-7 Δ L = 2 operators which generate neutrino masses at one- and/or two-loop level without and with dark matter candidates, (II) models with dark matter which lead to neutrino masses at one-loop level and (III) models with particles in the adjoint representation of SU(3). In class (I), gauge couplings unify in a few models and adding dark matter amplifies the chances for unification. In class (II), about a quarter of the models admits gauge coupling unification. In class (III), none of the models leads to gauge coupling unification. Regarding the scale of unification, we find values between 1014 GeV and 1016 GeV for models belonging to class (I) without dark matter, whereas models in class (I) with dark matter as well as models of class (II) prefer values in the range 5·1010 - 5·1014 GeV.

  13. Toward a New Paradigm for the Unification of Radio Loud AGN and its Connection to Accretion

    NASA Technical Reports Server (NTRS)

    Georganpoulos, Markos; Meyer, Eileen T.; Fossati, Giovanni; Lister, Matthew L.

    2012-01-01

    We recently argued [21J that the collective properties. of radio loud active galactic nuclei point to the existence of two families of sources, one of powerful sources with single velocity jets and one of weaker jets with significant velocity gradients in the radiating plasma. These families also correspond to different accretion modes and therefore different thermal and emission line intrinsic properties: powerful sources have radiatively efficient accretion disks, while in weak sources accretion must be radiatively inefficient. Here, after we briefly review of our recent work, we present the following findings that support our unification scheme: (i) along the broken sequence of aligned objects, the jet kinetic power increases. (ii) in the powerful branch of the sequence of aligned objects the fraction of BLLs decreases with increasing jet power. (iii) for powerful sources, the fraction of BLLs increases for more un-aligned objects, as measured by the core to extended radio emission. Our results are also compatible with the possibility that a given accretion power produces jets of comparable kinetic power.

  14. The evolution of obscured AGN

    NASA Astrophysics Data System (ADS)

    Brightman, Murray

    2012-09-01

    We present results on the evolution of Compton thick AGN with redshift, and the nature of this obscuration, important for understanding the accretion history of the universe and for AGN unification schemes. We use lessons learned from spectral complexity of local AGN (Brightman & Nandra 2012) and up to date spectral models of heavily absorbed AGN, which take into account Compton scattering, self consistent Fe Ka modeling and the geometry of the circumnuclear material (Brightman & Nandra 2011), to optimise our identification of Compton thick AGN and understanding of the obscuring material. Results from the Chandra Deep Field South are presented (Brightman & Ueda, 2012), which show an increasing fraction of CTAGN with redshift and that most heavily obscured AGN are geometrically deeply buried in material, as well as new results from and extension of this study to AEGIS-XD and Chandra-COSMOS survey, which aim to fully characterise the dependence of heavy AGN obscuration on redshift and luminosity.

  15. The Changing Looks of AGN

    NASA Astrophysics Data System (ADS)

    LaMassa, S.

    2015-09-01

    According to the AGN unification model, the difference between Type 1 and Type 2 AGN is explained by the orientation of a circumnuclear obscuring torus to the observer's line of sight. Observations of seemingly anomalous sources challenge this theory. A handful of AGN have been discovered which have transitioned from Type 1, with strong, prominent broad-emission lines, to Type 1.8 or 1.9, with weak broad components to only H-alpha and/or H-beta, or vice versa. The rate of discovery of these objects has increased this past year thanks to the Sloan Digital Sky Survey BOSS and TDSS surveys which have repeated spectroscopic observations of AGN. While in some cases this transition can be explained by circumnuclear clouds eclipsing the broad line region, it seems clear that stochastic accretion is responsible for other changing-look AGN. In this talk, I will discuss the changing-look AGN discovered thus far and the implications these objects have for AGN unification and the intermittency of AGN activity.

  16. A New Catalog of Type 1 AGNs and its Implications on the AGN Unified Model

    NASA Astrophysics Data System (ADS)

    Oh, Kyuseok; Yi, Sukyoung K.; Schawinski, Kevin; Koss, Michael; Trakhtenbrot, Benny; Soto, Kurt

    2015-07-01

    We have recently identified a substantial number of type 1 active galactic nuclei (AGNs) featuring weak broad-line regions (BLRs) at z\\lt 0.2 from detailed analysis of galaxy spectra in the Sloan Digital Sky Survey Data Release 7. These objects predominantly show a stellar continuum but also a broad Hα emission line, indicating the presence of a low-luminosity AGN oriented so that we are viewing the central engine directly without significant obscuration. These accreting black holes have previously eluded detection due to their weak nature. The newly discovered BLR AGNs have increased the number of known type 1 AGNs by 49%. Some of these new BLR AGNs were detected with the Chandra X-ray Observatory, and their X-ray properties confirm that they are indeed type 1 AGNs. Based on our new and more complete catalog of type 1 AGNs, we derived the type 1 fraction of AGNs as a function of [O iii] λ 5007 emission luminosity and explored the possible dilution effect on obscured AGNs due to star formation. The new type 1 AGN fraction shows much more complex behavior with respect to black hole mass and bolometric luminosity than has been suggested previously by the existing receding torus model. The type 1 AGN fraction is sensitive to both of these factors, and there seems to be a sweet spot (ridge) in the diagram of black hole mass and bolometric luminosity. Furthermore, we present the possibility that the Eddington ratio plays a role in determining opening angles.

  17. Constraints on gauge-Higgs unification models at the LHC

    NASA Astrophysics Data System (ADS)

    Kitazawa, Noriaki; Sakai, Yuki

    2016-02-01

    We examine the possibility of observing the Kaluza-Klein (KK) gluons in gauge-Higgs unification models at the LHC with the energy s=14 TeV. We consider a benchmark model with the gauge symmetry SU(3)C×SU(3)W in five-dimensional spacetime, where SU(3)C is the gauge symmetry of the strong interaction and SU(3)W is that for the electroweak interaction and a Higgs doublet field. It is natural in general to introduce SU(3)C gauge symmetry in five-dimensional spacetime as well as SU(3)W gauge symmetry in gauge-Higgs unification (GHU) models. Since the fifth dimension is compactified to S1/Z 2 orbifold, there are KK modes of gluons in low-energy effective theory in four-dimensional spacetime. We investigate the resonance contribution of the first KK gluon to dijet invariant mass distribution at the LHC, and provide signal-to-noise ratios in various cases of KK gluon masses and kinematical cuts. Although the results are given in a specific benchmark model, we discuss their application to general GHU models with KK gluons. GHU models can be verified or constrained through the physics of the strong interaction, though they are proposed to solve the naturalness problem in electroweak symmetry breaking.

  18. Models of the Optical/Ultraviolet Continuum Polarization in Active Galactic Nuclei: Implications for Unification Schemes

    NASA Astrophysics Data System (ADS)

    Kartje, John F.

    1995-10-01

    I have computed the 1200-8000 A thermal continuum polarization induced by gas and dust arranged in configurations compatible with current active galactic nuclei (AGNs) unification schemes. Both uniform- density tori and stratified-density disk-driven winds were considered. A Monte Carlo radiative transfer code was developed which includes the polarization mechanisms of electron and dust scattering as well as dichroic extinction by aligned grains. A Galactic-type grain population was assumed. Based on these calculations, I propose a new interpretation of many of the observed polarization traits of Seyfert galaxies and QSOs: namely, that the polarization in these sources is induced by the same optically thick material which is assumed to obscure the central engine in unification schemes. In particular, I suggest that stratified-density winds could provide a natural explanation (and one consistent with unification models) of the polarization trends observed in Seyfert galaxies. Such winds can display polarizations (P ≲ 20%) oriented perpendicular to the axis along viewing angles inclined to the axis by θ0 ≳ 45° in well-collimated winds, this polarization shifts to smaller magnitudes (P ≲ 2%) and parallel orientations for more face-on viewing, consistent with the patterns observed in Seyfert 2 and Seyfert 1 sources, respectively. In less-collimated winds, scattering alone tends to produce parallel orientations for all viewing angles; perpendicular polarization at large θ0 can result if there is a high degree of magnetic grain alignment. The simplest torus models (i.e., uniform-density, opaque gas and dust) do not reproduce this flip in polarization position angle. Furthermore, they generally display high polarization magnitudes (P ≳ 10%) along most viewing angles θ0 > θ∞ (where θ is the torus half-opening angle) and negligible polarization along θ0 > θ∞. Unlike previous models for AGN polarization which invoke scattering by optically thin electron

  19. The Radio/X-Ray Correlation and the Unification of Low Power Black Holes

    NASA Astrophysics Data System (ADS)

    Körding, E.; Falcke, H.

    We present a unification scheme for active galactic nuclei (AGN) and black hole X-ray binaries (XRBs) using a symbiotic disk/jet model. Scale invariance and energy conservation are used to derive analytical scaling laws for the emission of a jet and allow us to identify the main parameters of the system: the mass of the central black hole and the accretion rate. The developed model can be used to argue for a unifying view of all weakly accreting black holes: a unification of XRBs and AGN. We classify the zoo of AGN in jet and disk dominated sources and test the unification scheme of weakly accreting sources by establishing a universal radio/X-ray correlation for XRBs and AGN. We briefly discuss jets in highly accreting systems.

  20. Gauge coupling unification in a classically scale invariant model

    NASA Astrophysics Data System (ADS)

    Haba, Naoyuki; Ishida, Hiroyuki; Takahashi, Ryo; Yamaguchi, Yuya

    2016-02-01

    There are a lot of works within a class of classically scale invariant model, which is motivated by solving the gauge hierarchy problem. In this context, the Higgs mass vanishes at the UV scale due to the classically scale invariance, and is generated via the Coleman-Weinberg mechanism. Since the mass generation should occur not so far from the electroweak scale, we extend the standard model only around the TeV scale. We construct a model which can achieve the gauge coupling unification at the UV scale. In the same way, the model can realize the vacuum stability, smallness of active neutrino masses, baryon asymmetry of the universe, and dark matter relic abundance. The model predicts the existence vector-like fermions charged under SU(3) C with masses lower than 1 TeV, and the SM singlet Majorana dark matter with mass lower than 2.6 TeV.

  1. Accretion-ejection models for AGN jets

    NASA Astrophysics Data System (ADS)

    Zanni, C.

    2008-10-01

    It is likely that jets from Active Galactic Nuclei derive their energy from accretion onto the central black hole. It is actually possible to fuel the jets by extracting energy and angular momentum from the accretion disk and/or the rotating black hole via the action of large-scale magnetic fields. In this talk I will first present results of analytical and numerical models of the launching process of jets from magnetized accretion disks: I will show that, although a sizeable fraction of the accretion power goes into the jets, these outflows are presumably only mildly relativistic. In the second place, I will therefore suggest that the strongly relativistic components observed at the VLBI scales are accelerated in the innermost parts of the AGNs by Blandford-Znajek and/or Compton-rocket processes. Nonetheless, the non-relativistic disk-wind is needed to collimate the relativistic component and to reproduce the total power of extragalactic jets.

  2. Neutrino mass, proton decay, and neutron oscillations as crucial tests of unification models (A Review)

    PubMed Central

    Marshak, R. E.

    1982-01-01

    Several crucial tests of three popular unification models (of strong, electromagnetic, and weak interactions) are described. The models are SU(5) and SO(10) at the grand unification theory (GUT) level and SU(4)C × SU(2)L × SU(2)R at the partial unification theory (PUT) level. The tests selected for discussion are the finiteness of the neutrino mass in the electron volt region, the decay of protons into antileptons in the range of 1031± yr, and the detectability of neutron oscillations at all. The PUT group can also be tested by establishing the existence of four generations of quarks and leptons.

  3. An explicit SU(12) family and flavor unification model with natural fermion masses and mixings

    SciTech Connect

    Albright, Carl H.; Feger, Robert P.; Kephart, Thomas W.

    2012-07-01

    We present an SU(12) unification model with three light chiral families, avoiding any external flavor symmetries. The hierarchy of quark and lepton masses and mixings is explained by higher dimensional Yukawa interactions involving Higgs bosons that contain SU(5) singlet fields with VEVs about 50 times smaller than the SU(12) unification scale. The presented model has been analyzed in detail and found to be in very good agreement with the observed quark and lepton masses and mixings.

  4. Model-based object classification using unification grammars and abstract representations

    NASA Astrophysics Data System (ADS)

    Liburdy, Kathleen A.; Schalkoff, Robert J.

    1993-04-01

    The design and implementation of a high level computer vision system which performs object classification is described. General object labelling and functional analysis require models of classes which display a wide range of geometric variations. A large representational gap exists between abstract criteria such as `graspable' and current geometric image descriptions. The vision system developed and described in this work addresses this problem and implements solutions based on a fusion of semantics, unification, and formal language theory. Object models are represented using unification grammars, which provide a framework for the integration of structure and semantics. A methodology for the derivation of symbolic image descriptions capable of interacting with the grammar-based models is described and implemented. A unification-based parser developed for this system achieves object classification by determining if the symbolic image description can be unified with the abstract criteria of an object model. Future research directions are indicated.

  5. 331 models and grand unification: From minimal SU(5) to minimal SU(6)

    NASA Astrophysics Data System (ADS)

    Deppisch, Frank F.; Hati, Chandan; Patra, Sudhanwa; Sarkar, Utpal; Valle, José W. F.

    2016-11-01

    We consider the possibility of grand unification of the SU(3)c ⊗ SU(3)L ⊗ U(1)X model in an SU(6) gauge unification group. Two possibilities arise. Unlike other conventional grand unified theories, in SU(6) one can embed the 331 model as a subgroup such that different multiplets appear with different multiplicities. Such a scenario may emerge from the flux breaking of the unified group in an E(6) F-theory GUT. This provides new ways of achieving gauge coupling unification in 331 models while providing the radiative origin of neutrino masses. Alternatively, a sequential variant of the SU(3)c ⊗ SU(3)L ⊗ U(1)X model can fit within a minimal SU(6) grand unification, which in turn can be a natural E(6) subgroup. This minimal SU(6) embedding does not require any bulk exotics to account for the chiral families while allowing for a TeV scale SU(3)c ⊗ SU(3)L ⊗ U(1)X model with seesaw-type neutrino masses.

  6. The Evolution of the AGN population in the MORGANA model

    NASA Astrophysics Data System (ADS)

    Fontanot, F.; Monaco, P.; Cristiani, S.; Tozzi, P.

    2008-10-01

    We present the results of the MOdel for the Rise of Galaxies aNd Agns (MORGANA), that includes in a self-consistent way the accretion of matter onto Super-Massive Black Holes. We compare MORGANA predictions to the observed evolution of the AGN space density (inferred from optical and X-ray surveys) and we find that that it is possible to reproduce the apparent downsizing of the AGN population in the framework of concordance cosmology. We will show that this result is likely due to the improved treatment of gas cooling and feedback in MORGANA, and in particular to the modeling of the stellar kinetic feedback, arising in star-forming bulges as a consequence of the level of turbolence. On the other hand, the predicted low-mass end of BH-bulge relation is steeper than observed: we discuss this disagreement on the light of the predicted excess of small bulges, which is common to several models of galaxy formation and evolution. Finally we will show that a stronger constrain on the relative importance of the physical processes involved in the build up of the AGN population move from the observed redshift evolution of the BH-Bulge relation.

  7. Accretion disk modeling of AGN continuum using non-LTE stellar atmospheres. [active galactic nuclei (AGN)

    NASA Technical Reports Server (NTRS)

    Sun, Wei-Hsin; Malkan, Matthew A.

    1988-01-01

    Active galactic nuclei (AGN) accretion disk spectra were calculated using non-LTE stellar atmosphere models for Kerr and Schwarzschild geometries. It is found that the Lyman limit absorption edge, probably the most conclusive observational evidence for the accretion disk, would be drastically distorted and displaced by the relativistic effects from the large gravitational field of the central black hole and strong Doppler motion of emitting material on the disk surface. These effects are especially pronounced in the Kerr geometry. The strength of the Lyman limit absorption is very sensitive to the surface gravity in the stellar atmosphere models used. For models at the same temperature but different surface gravities, the strength of the Lyman edge exhibits an almost exponential decrease as the surface gravity approach the Eddington limit, which should approximate the thin disk atmosphere. The relativistic effects as well as the vanishing of the Lyman edge at the Eddington gravity may be the reasons that not many Lyman edges in the rest frames of AGNs and quasars are found.

  8. Corpus-Based Optimization of Language Models Derived from Unification Grammars

    NASA Technical Reports Server (NTRS)

    Rayner, Manny; Hockey, Beth Ann; James, Frankie; Bratt, Harry; Bratt, Elizabeth O.; Gawron, Mark; Goldwater, Sharon; Dowding, John; Bhagat, Amrita

    2000-01-01

    We describe a technique which makes it feasible to improve the performance of a language model derived from a manually constructed unification grammar, using low-quality untranscribed speech data and a minimum of human annotation. The method is on a medium-vocabulary spoken language command and control task.

  9. Modeling the reverberation of optical polarization in AGN

    NASA Astrophysics Data System (ADS)

    Rojas Lobos, P. A.; Goosmann, R.; Marin, F.

    2016-12-01

    According to the standard paradigm, the strong and compact luminosity of active galactic nuclei (AGN) is due to multi-temperature black body emission originating from an accretion disk formed around a supermassive black hole. This central engine is thought to be surrounded by a dusty region along the equatorial plane and by ionized winds along the poles. The innermost regions cannot yet be resolved neither in the optical nor in the infrared and it is fair to say that we still lack a satisfactory understanding of the physical processes, geometry and composition of the central (sub-parsec) components of AGN. Like spectral or polarimetric observations, the reverberation data needs to be modeled in order to infer constraints on the AGN geometry (such as the inner radius or the half-opening angle of the dusty torus). In this research note, we present preliminary modeling results using a time-dependent Monte Carlo method to solve the radiative transfer in a simplified AGN set up. We investigate different model configurations using both polarization and time lags and find a high dependency on the geometry to the time-lag response. For all models there is a clear distinction between edge-on or face-on viewing angles for fluxes and time lags, the later showing a higher wavelength-dependence than the former. Time lags, polarization and fluxes point toward a clear dichotomy between the different inclinations of AGN, a method that could help us to determine the true orientation of the nucleus in Seyfert galaxies.

  10. Unification and mechanistic detail as drivers of model construction: models of networks in economics and sociology.

    PubMed

    Kuorikoski, Jaakko; Marchionni, Caterina

    2014-12-01

    We examine the diversity of strategies of modelling networks in (micro) economics and (analytical) sociology. Field-specific conceptions of what explaining (with) networks amounts to or systematic preference for certain kinds of explanatory factors are not sufficient to account for differences in modelling methodologies. We argue that network models in both sociology and economics are abstract models of network mechanisms and that differences in their modelling strategies derive to a large extent from field-specific conceptions of the way in which a good model should be a general one. Whereas the economics models aim at unification, the sociological models aim at a set of mechanism schemas that are extrapolatable to the extent that the underlying psychological mechanisms are general. These conceptions of generality induce specific biases in mechanistic explanation and are related to different views of when knowledge from different fields should be seen as relevant.

  11. A model for dark matter, naturalness and a complete gauge unification

    SciTech Connect

    Kainulainen, Kimmo; Virkajärvi, Jussi; Tuominen, Kimmo E-mail: kimmo.i.tuominen@helsinki.fi

    2015-07-01

    We consider dark matter in a minimal extension of the Standard Model (SM) which breaks electroweak symmetry dynamically and leads to a complete unification of the SM and technicolor coupling constants. The unification scale is determined to be M{sub U} ≈ 2.2 × 10{sup 15} GeV and the unified coupling α{sub U} ≈ 0.0304. Moreover, unification strongly suggest that the technicolor sector of the model must become strong at the scale of O(TeV) . The model also contains a tightly constrained sector of mixing neutral fields stabilized by a discrete symmetry. We find the lightest of these states can be DM with a mass in the range 0m{sub DM} ≈ 3–080 GeV . We find a large set of parameters that satisfy all available constraints from colliders and from dark matter search experiments. However, most of the available parameter space is within the reach of the next generation of DM search experiments. The model is also sensitive to a modest improvement in the measurement of the precision electroweak parameters.

  12. A model for dark matter, naturalness and a complete gauge unification

    SciTech Connect

    Kainulainen, Kimmo; Tuominen, Kimmo; Virkajärvi, Jussi

    2015-07-21

    We consider dark matter in a minimal extension of the Standard Model (SM) which breaks electroweak symmetry dynamically and leads to a complete unification of the SM and technicolor coupling constants. The unification scale is determined to be M{sub U}≈2.2×10{sup 15} GeV and the unified coupling α{sub U}≈0.0304. Moreover, unification strongly suggest that the technicolor sector of the model must become strong at the scale of O(TeV). The model also contains a tightly constrained sector of mixing neutral fields stabilized by a discrete symmetry. We find the lightest of these states can be DM with a mass in the range m{sub DM}≈30–800 GeV. We find a large set of parameters that satisfy all available constraints from colliders and from dark matter search experiments. However, most of the available parameter space is within the reach of the next generation of DM search experiments. The model is also sensitive to a modest improvement in the measurement of the precision electroweak parameters.

  13. The AGN Jet Model of the Fermi Bubbles

    NASA Astrophysics Data System (ADS)

    Guo, Fulai

    2017-01-01

    The nature and origin of the Fermi bubbles detected in the inner Galaxy remain elusive. In this paper, we briefly discuss some recent theoretical and observational developments, with a focus on the AGN jet model. Analogous to radio lobes observed in massive galaxies, the Fermi bubbles could be naturally produced by a pair of opposing jets emanating nearly along the Galaxy's rotation axis from the Galactic center. Our two-fluid hydrodynamic simulations reproduce quite well the bubble location and shape, and interface instabilities at the bubble surface could be effectively suppressed by shear viscosity. We briefly comment on some potential issues related to our model, which may lead to future progress.

  14. Constraining the properties of AGN host galaxies with spectral energy distribution modelling

    NASA Astrophysics Data System (ADS)

    Ciesla, L.; Charmandaris, V.; Georgakakis, A.; Bernhard, E.; Mitchell, P. D.; Buat, V.; Elbaz, D.; LeFloc'h, E.; Lacey, C. G.; Magdis, G. E.; Xilouris, M.

    2015-04-01

    Detailed studies of the spectral energy distribution (SED) of normal galaxies have increasingly been used to understand the physical mechanism dominating their integrated emission, mainly owing to the availability of high quality multi-wavelength data from the UV to the far-infrared (FIR). However, systems hosting dust-enshrouded nuclear starbursts and/or an accreting supermassive black hole (an active galactic nucleus or AGN) are especially challenging to study. This is due to the complex interplay between the heating by massive stars and the AGN, the absorption and emission of radiation from dust, as well as the presence of the underlying old stellar population. We used the latest release of CIGALE, a fast state-of-the-art galaxy SED-fitting model relying on energy balance, to study the influence of an AGN in a self consistent manner in estimating both the star formation rate (SFR) and stellar mass in galaxies, as well as to calculate the contribution of the AGN to the power output of the host. Using the semi-analytical galaxy formation model galform, we created a suite of mock galaxy SEDs using realistic star formation histories (SFH). We also added an AGN of Type-1, Type-2, or intermediate-type whose contribution to the bolometric luminosity can be variable. We performed an SED-fitting of these catalogues with CIGALE, assuming three different SFHs: a single-exponentially-decreasing (1τ-dec), a double-exponentially-decreasing (2τ-dec), and a delayed SFH. Constraining the overall contribution of an AGN to the total infrared luminosity (fracAGN) is very challenging for fracAGN< 20%, with uncertainties of ~5-30% for higher fractions depending on the AGN type, while FIR and sub-mm are essential. The AGN power has an impact on the estimation of M∗ in Type-1 and intermediate-type AGNs but has no effect on galaxies hosting Type-2 AGNs. We find that in the absence of AGN emission, the best estimates of M∗ are obtained using the 2τ-dec model but at the expense of

  15. Relativistic HD and MHD modelling for AGN jets

    NASA Astrophysics Data System (ADS)

    Keppens, R.; Porth, O.; Monceau-Baroux, R.; Walg, S.

    2013-12-01

    Relativistic hydro and magnetohydrodynamics (MHD) provide a continuum fluid description for plasma dynamics characterized by shock-dominated flows approaching the speed of light. Significant progress in its numerical modelling emerged in the last two decades; we highlight selected examples of modern grid-adaptive, massively parallel simulations realized by our open-source software MPI-AMRVAC (Keppens et al 2012 J. Comput. Phys. 231 718). Hydrodynamical models quantify how energy transfer from active galactic nuclei (AGN) jets to their surrounding interstellar/intergalactic medium (ISM/IGM) gets mediated through shocks and various fluid instability mechanisms (Monceau-Baroux et al 2012 Astron. Astrophys. 545 A62). With jet parameters representative for Fanaroff-Riley type-II jets with finite opening angles, we can quantify the ISM volumes affected by jet injection and distinguish the roles of mixing versus shock-heating in cocoon regions. This provides insight in energy feedback by AGN jets, usually incorporated parametrically in cosmological evolution scenarios. We discuss recent axisymmetric studies up to full 3D simulations for precessing relativistic jets, where synthetic radio maps can confront observations. While relativistic hydrodynamic models allow one to better constrain dynamical parameters like the Lorentz factor and density contrast between jets and their surroundings, the role of magnetic fields in AGN jet dynamics and propagation characteristics needs full relativistic MHD treatments. Then, we can demonstrate the collimating properties of an overal helical magnetic field backbone and study differences between poloidal versus toroidal field dominated scenarios (Keppens et al 2008 Astron. Astrophys. 486 663). Full 3D simulations allow one to consider the fate of non-axisymmetric perturbations on relativistic jet propagation from rotating magnetospheres (Porth 2013 Mon. Not. R. Astron. Soc. 429 2482). Self-stabilization mechanisms related to the detailed

  16. The Angular Clustering of WISE-Selected AGN: Different Haloes for Obscured and Unobscured AGN

    NASA Astrophysics Data System (ADS)

    Yan, Lin

    2015-08-01

    We calculate the angular correlation function for a sample of 170,000 AGN extracted from the Wide-field Infrared Survey Explorer (WISE) catalog, selected to have red mid-IR colors (W1 - W2 > 0.8) and 4.6 micron flux densities brighter than 0.14 mJy). The sample is expected to be >90% reliable at identifying AGN, and to have a mean redshift of z=1.1. In total, the angular clustering of WISE-AGN is roughly similar to that of optical AGN. We cross-match these objects with the photometric SDSS catalog and distinguish obscured sources with (r - W2) > 6 from bluer, unobscured AGN. Obscured sources present a higher clustering signal than unobscured sources. Since the host galaxy morphologies of obscured AGN are not typical red sequence elliptical galaxies and show disks in many cases, it is unlikely that the increased clustering strength of the obscured population is driven by a host galaxy segregation bias. By using relatively complete redshift distributions from the COSMOS survey, we find obscured sources at mean redshift z=0.9 have a bias of b = 2.9 \\pm 0.6 and are hosted in dark matter halos with a typical mass of log(M/M_odot)~13.5. In contrast, unobscured AGN at z~1.1 have a bias of b = 1.6 \\pm 0.6 and inhabit halos of log(M/M_odot)~12.4. These findings suggest that obscured AGN inhabit denser environments than unobscured AGN, and are difficult to reconcile with the simplest AGN unification models, where obscuration is driven solely by orientation.

  17. AGN Absorption Linked to Host Galaxies

    NASA Astrophysics Data System (ADS)

    Juneau, Stéphanie

    2014-07-01

    Multiwavelength identification of AGN is crucial not only to obtain a more complete census, but also to learn about the physical state of the nuclear activity (obscuration, efficiency, etc.). A panchromatic strategy plays an especially important role when the host galaxies are star-forming. Selecting far-Infrared galaxies at 0.3AGN tracers in the X-ray, optical spectra, mid-infrared, and radio regimes, we found a twice higher AGN fraction than previous studies, thanks to the combined AGN identification methods and in particular the recent Mass-Excitation (MEx) diagnostic diagram. We furthermore find an intriguing relation between AGN X-ray absorption and the specific star formation rate (sSFR) of the host galaxies, indicating a physical link between X-ray absorption and either the gas fraction or the gas geometry in the hosts. These findings have implications for our current understanding of both the AGN unification model and the nature of the black hole-galaxy connection.

  18. Unification and Dark Matter in a Minimal Scalar Extension of the Standard Model

    SciTech Connect

    Lisanti, Mariangela; Wacker, Jay G.

    2007-04-25

    The six Higgs doublet model is a minimal extension of the Standard Model (SM) that addresses dark matter and gauge coupling unification. Another Higgs doublet in the 5 representation of a discrete symmetry group, such as S{sub 6}, is added to the SM. The lightest components of the 5-Higgs are neutral, stable and serve as dark matter so long as the discrete symmetry is not broken. Direct and indirect detection signals, as well as collider signatures are discussed. The five-fold multiplicity of the dark matter decreases its mass and typically helps make the dark matter more visible in upcoming experiments.

  19. A possible grand unification theory with 331 models

    SciTech Connect

    Gaitan, R.; Martinez, R.

    2009-04-20

    The 331 models with three families appear in a natural way by using the anomaly cancellations. In the present work we want to study the possibility to unify this class of models with three families into a SU(7) gauge group. The fermion contents are given by 7*, 21 and 35* irreducible representations.

  20. Minimal Pati-Salam model from string theory unification

    SciTech Connect

    Dent, James B.; Kephart, Thomas W.

    2008-06-01

    We provide what we believe is the minimal three family N=1 SUSY and conformal Pati-Salam model from type IIB superstring theory. This Z{sub 3} orbifolded AdS x S{sup 5} model has long lived protons and has potential phenomenological consequences for LHC (Large Hadron Collider)

  1. Unification of models for choice between delayed reinforcers.

    PubMed Central

    Killeen, P R; Fantino, E

    1990-01-01

    Two models for choice between delayed reinforcers, Fantino's delay-reduction theory and Killeen's incentive theory, are reviewed. Incentive theory is amended to incorporate the effects of arousal on alternate types of behavior that might block the reinforcement of the target behavior. This amended version is shown to differ from the delay-reduction theory in a term that is an exponential in incentive theory and a difference in delay-reduction theory. A power series approximation to the exponential generates a model that is formally identical with delay-reduction theory. Correlations between delay-reduction theory and the amended incentive theory show excellent congruence over a range of experimental conditions. Although the assumptions that gave rise to delay-reduction theory and incentive theory remain different and testable, the models deriving from the theories are unlikely to be discriminable by parametric experimental tests. This congruence of the models is recognized by naming the common model the delayed reinforcement model, which is then compared with other models of choice such as Killeen and Fetterman's (1988) behavioral theory of timing, Mazur's (1984) equivalence rule, and Vaughan's (1985) melioration theory. PMID:2299288

  2. LHC phenomenology of SO(10) models with Yukawa unification. II.

    NASA Astrophysics Data System (ADS)

    Anandakrishnan, Archana; Bryant, B. Charles; Raby, Stuart

    2014-07-01

    In this paper we study Yukawa-unified SO(10) supersymmetric (SUSY) grand unified theories (GUTs) with two types of SO(10) boundary conditions: (i) universal gaugino masses and (ii) nonuniversal gaugino masses with effective "mirage" mediation. With these boundary conditions, we perform a global χ2 analysis to obtain the parameters consistent with 11 low energy observables, including the top, bottom, and tau masses. Both boundary conditions have universal scalar masses and "just so" splitting for the up- and down-type Higgs masses. In these models, the third family scalars are lighter than the first two families and the gauginos are lighter than all the scalars. We therefore focus on the gluino phenomenology in these models. In particular, we estimate the lowest allowed gluino mass in our models coming from the most recent LHC data and compare this to limits obtained using simplified models. We find that the lower bound on Mg ˜ in Yukawa-unified SO(10) SUSY GUTs is generically ˜1.2 TEV at the 1σ level unless there is considerable degeneracy between the gluino and the lightest supersymmetric particle, in which case the bounds are much weaker. Hence many of our benchmark points are not ruled out by the present LHC data and are still viable models which can be tested at LHC 14.

  3. Modeling production of e+/--pair plasma in AGNs

    NASA Astrophysics Data System (ADS)

    Ford, Alex; Medvedev, Mikhail V.

    2016-10-01

    Processes around spinning supermassive black holes in active galactic nuclei (AGN) are believed to determine how relativistic jets are launched and how the black hole energy is extracted. The key question in these processes is the origin of plasma in black hole magnetospheres. The only reasonable mechanism is believed to be the electron-position cascade - the multistage process involving seed photons from an accretion disk, which are Compton up-scattered by charges accelerated in a gap region of a force-free magnetosphere with subsequent photon-photon pair production. In order to explore the process of the e+/- plasma production, we developed a numerical code which models the dynamics of the cascade along magnetic field lines. We demonstrate that plasma production is sensitive to the spectrum of the ambient photon and magnetic fields, the black hole mass and spin, and other parameters. We discuss the results and observational predictions. Supported by KU CLAS and DOE Grant ID0000225143 (07/01/16).

  4. Clustering, Cosmology and a New Era of Black Hole Demographics: The Conditional Luminosity Function of AGNs

    NASA Astrophysics Data System (ADS)

    Ballantyne, David R.

    2016-04-01

    Deep X-ray surveys have provided a comprehensive and largely unbiased view of AGN evolution stretching back to z˜5. However, it has been challenging to use the survey results to connect this evolution to the cosmological environment that AGNs inhabit. Exploring this connection will be crucial to understanding the triggering mechanisms of AGNs and how these processes manifest in observations at all wavelengths. In anticipation of upcoming wide-field X-ray surveys that will allow quantitative analysis of AGN environments, we present a method to observationally constrain the Conditional Luminosity Function (CLF) of AGNs at a specific z. Once measured, the CLF allows the calculation of the AGN bias, mean dark matter halo mass, AGN lifetime, halo occupation number, and AGN correlation function - all as a function of luminosity. The CLF can be constrained using a measurement of the X-ray luminosity function and the correlation length at different luminosities. The method is demonstrated at z ≈0 and 0.9, and clear luminosity dependence in the AGN bias and mean halo mass is predicted at both z. The results support the idea that there are at least two different modes of AGN triggering: one, at high luminosity, that only occurs in high mass, highly biased haloes, and one that can occur over a wide range of halo masses and leads to luminosities that are correlated with halo mass. This latter mode dominates at z<0.9. The CLFs for Type 2 and Type 1 AGNs are also constrained at z ≈0, and we find evidence that unobscured quasars are more likely to be found in higher mass halos than obscured quasars. Thus, the AGN unification model seems to fail at quasar luminosities.

  5. How to model AGN feedback in cosmological simulations?

    NASA Astrophysics Data System (ADS)

    Sijacki, Debora

    2015-08-01

    Hydrodynamical cosmological simulations are one of the most powerful tools to study the formation and evolution of galaxies in the fully non-linear regime. Despite several recent successes in simulating Milky Way look-alikes, self-consistent, ab-initio models are still a long way off. In this talk I will review numerical and physical uncertainties plaguing current state-of-the-art cosmological simulations of galaxy formation. I will then discuss which feedback mechanisms are needed to reproduce realistic stellar masses and galaxy morphologies in the present day Universe and argue that the black hole feedback is necessary for the quenching of massive galaxies. I will then demonstrate how black hole - host galaxy scaling relations depend on galaxy morphology and colour, highlighting the implications for the co-evolutionary picture between galaxies and their central black holes. In the second part of the talk I will present a novel method that permits to resolve gas flows around black holes all the way from large cosmological scales to the Bondi radii of black holes themselves. I will demonstrate that with this new numerical technique it is possible to estimate much more accurately gas properties in the vicinity of black holes than has been feasible before in galaxy and cosmological simulations, allowing to track reliably gas angular momentum transport from Mpc to pc scales. Finally, I will also discuss if AGN-driven outflows are more likely to be energy- or momentum-driven and what implications this has for the redshift evolution of black hole - host galaxy scaling relations.

  6. Theoretical uncertainties due to AGN subgrid models in predictions of galaxy cluster observable properties

    NASA Astrophysics Data System (ADS)

    Yang, H.-Y. Karen; Sutter, P. M.; Ricker, Paul M.

    2012-12-01

    Cosmological constraints derived from galaxy clusters rely on accurate predictions of cluster observable properties, in which feedback from active galactic nuclei (AGN) is a critical component. In order to model the physical effects due to supermassive black holes (SMBH) on cosmological scales, subgrid modelling is required, and a variety of implementations have been developed in the literature. However, theoretical uncertainties due to model and parameter variations are not yet well understood, limiting the predictive power of simulations including AGN feedback. By performing a detailed parameter-sensitivity study in a single cluster using several commonly adopted AGN accretion and feedback models with FLASH, we quantify the model uncertainties in predictions of cluster integrated properties. We find that quantities that are more sensitive to gas density have larger uncertainties (˜20 per cent for Mgas and a factor of ˜2 for LX at R500), whereas TX, YSZ and YX are more robust (˜10-20 per cent at R500). To make predictions beyond this level of accuracy would require more constraints on the most relevant parameters: the accretion model, mechanical heating efficiency and size of feedback region. By studying the impact of AGN feedback on the scaling relations, we find that an anti-correlation exists between Mgas and TX, which is another reason why YSZ and YX are excellent mass proxies. This anti-correlation also implies that AGN feedback is likely to be an important source of intrinsic scatter in the Mgas-TX and LX-TX relations.

  7. Modeling optical and UV polarization of AGNs. III. From uniform-density to clumpy regions

    NASA Astrophysics Data System (ADS)

    Marin, F.; Goosmann, R. W.; Gaskell, C. M.

    2015-05-01

    Context. A growing body of evidence suggests that some, if not all, scattering regions of active galactic nuclei (AGNs) are clumpy. The inner AGN components cannot be spatially resolved with current instruments and must be studied by numerical simulations of observed spectroscopy and polarization data. Aims: We run radiative transfer models in the optical/UV for a variety of AGN reprocessing regions with different distributions of clumpy scattering media. We obtain geometry-sensitive polarization spectra and images to improve our previous AGN models and their comparison with the observations. Methods: We use the latest public version 1.2 of the Monte Carlo code stokes presented in the first two papers of this series to model AGN reprocessing regions of increasing morphological complexity. We replace previously uniform-density media with up to thousands of constant-density clumps. We couple a continuum source to fragmented equatorial scattering regions, polar outflows, and toroidal obscuring dust regions and investigate a wide range of geometries. We also consider different levels of fragmentation in each scattering region to evaluate the importance of fragmentation for the net polarization of the AGN. Results: In comparison with uniform-density models, equatorial distributions of gas and dust clouds result in grayer spectra and show a decrease in the net polarization percentage at all lines of sight. The resulting polarization position angle depends on the morphology of the clumpy structure, with extended tori favoring parallel polarization while compact tori produce orthogonal polarization position angles. In the case of polar scattering regions, fragmentation increases the net polarization unless the cloud filling factor is small. A complete AGN model constructed from the individual, fragmented regions can produce low polarization percentages (<2%), with a parallel polarization angle for observer inclinations up to 70° for a torus half opening angle of 60°. For

  8. Photoionization modeling of GRO 1655-40: A scaled down AGN Warm Absrobers!

    NASA Astrophysics Data System (ADS)

    Kazanas, Demosthenes; Fukumura, Keigo; Shrader, Chris R.; Behar, Ehud; Tombesi, Francesco

    2016-04-01

    We present photoinization models of the absorption features Galactic X-ray Binary (XRB) by implementing the MHD accretion disk wind models employed to account for the ionization properties of the AGN Warm Absorbers (WA)(Fukumura et a. 2010). The implementation of the same models rests on the fact that the radial density profiles of these winds, n(r)~1/r, guarantees the correct values of the hydrogen equivalent column NH of the most important ionic species at the correct values of their ionization parameter ξ and velocity v. The similarity of the winds' ionization properties is broken only by the peak frequency of the ionizing SED, which is in the UV in AGN and in X-rays in XRBs. This difference implies that the inner regions of the XRB winds are far more ionized than those of AGN, resulting in much smaller velocities for the same ionic species (e.g. Fe XXV) in XRB (v~1,000 km/s) than in AGN (v~10,000 km/s), in agreement with observation. Estimates of the wind mass flux deduced from our photonization modeling, imply that the latter is much larger than that needed to power the observed X-ray emission, a property that appears to be generic from the Galactic to the AGN black hole mass range suggesting a common underlying structure.

  9. Minimal nonsupersymmetric S O (10 ) model: Gauge coupling unification, proton decay, and fermion masses

    NASA Astrophysics Data System (ADS)

    Babu, K. S.; Khan, S.

    2015-10-01

    We present a minimal renormalizable nonsupersymmetric S O (10 ) grand unified model with a symmetry breaking sector consisting of Higgs fields in the 5 4H+12 6H+1 0H representations. This model admits a single intermediate scale associated with Pati-Salam symmetry along with a discrete parity. Spontaneous symmetry breaking, the unification of gauge couplings, and proton lifetime estimates are studied in detail in this framework. Including threshold corrections self-consistently obtained from a full analysis of the Higgs potential, we show that the model is compatible with the current experimental bound on proton lifetime. The model generally predicts an upper bound of few times 1035 yr for proton lifetime, which is not too far from the present Super-Kamiokande limit of τp≳1.29 ×1034 yr . With the help of a Pecci-Quinn symmetry and the resulting axion, the model provides a suitable dark matter candidate while also solving the strong C P problem. The intermediate scale, MI≈(1013- 1014) GeV which is also the B -L scale, is of the right order for the right-handed neutrino mass which enables a successful description of light neutrino masses and oscillations. The Yukawa sector of the model consists of only two matrices in family space and leads to a predictive scenario for quark and lepton masses and mixings. The branching ratios for proton decay are calculable with the leading modes being p →e+π0 and p →ν ¯π+. Even though the model predicts no new physics within the reach of the LHC, the next-generation proton decay detectors and axion search experiments have the capability to reach a verdict on this minimal scenario.

  10. Unification Theory of Optimal Life Histories and Linear Demographic Models in Internal Stochasticity

    PubMed Central

    Oizumi, Ryo

    2014-01-01

    Life history of organisms is exposed to uncertainty generated by internal and external stochasticities. Internal stochasticity is generated by the randomness in each individual life history, such as randomness in food intake, genetic character and size growth rate, whereas external stochasticity is due to the environment. For instance, it is known that the external stochasticity tends to affect population growth rate negatively. It has been shown in a recent theoretical study using path-integral formulation in structured linear demographic models that internal stochasticity can affect population growth rate positively or negatively. However, internal stochasticity has not been the main subject of researches. Taking account of effect of internal stochasticity on the population growth rate, the fittest organism has the optimal control of life history affected by the stochasticity in the habitat. The study of this control is known as the optimal life schedule problems. In order to analyze the optimal control under internal stochasticity, we need to make use of “Stochastic Control Theory” in the optimal life schedule problem. There is, however, no such kind of theory unifying optimal life history and internal stochasticity. This study focuses on an extension of optimal life schedule problems to unify control theory of internal stochasticity into linear demographic models. First, we show the relationship between the general age-states linear demographic models and the stochastic control theory via several mathematical formulations, such as path–integral, integral equation, and transition matrix. Secondly, we apply our theory to a two-resource utilization model for two different breeding systems: semelparity and iteroparity. Finally, we show that the diversity of resources is important for species in a case. Our study shows that this unification theory can address risk hedges of life history in general age-states linear demographic models. PMID:24945258

  11. Star formation and obscuration in AGN: A sub-mm study of high-redshift mid-IR selected type-2 QSOs

    NASA Astrophysics Data System (ADS)

    Violino, Giulio; Stevens, Jason; Coppin, Kristen; Geach, James

    2016-08-01

    The AGN unification model describes unobscured and obscured AGN (AGN1 and AGN2) as identical sources, with their different observed properties explained solely by orientation effects; as a result, it predicts no difference in the host galaxies. As an alternative, a second scenario has been proposed in which type-2 AGN represent an earlier stage in the life of AGN characterized by dust-enshrouded host galaxies which contribute to the obscuration and higher star formation activity, at least at earlier epochs. To test this scenario we employ Herschel data at three different wavelengths (250, 350, 500 um) to study the far-IR-to-submm properties of a sample of mid-IR selected type 2 QSOs at high redshift (1.5AGN and star-formation activity and consequently derive FIR luminosities of the two components, as well as SFRs and dust masses. We propose a picture in which intermediate-level radio activity in the core (pc scale) of AGN is linked to the obscuration of the nucleus (perhaps via a merger) since our AGN1 have systematically lower radio luminosities than our AGN2.

  12. Interferometric IR observations: a diversity of dusty AGN tori

    NASA Astrophysics Data System (ADS)

    Burtscher, Leonard

    Interferometric observations in the infrared have resolved dusty structures on parsec and sub-parsec scales in more than two dozen AGNs by now -- a giant leap when considering that the first infrared interferometric observation of an extragalactic object is only about 10 years old. Since then, studies have confirmed the existence of dust in AGNs at its sublimation radius and have clearly dismissed models of very extended tori. Individual, well studied sources have been instrumental to reveal the complexity of these parsec-scale structures and statistical studies have shown a perplexing diversity in the population as a whole. Surprisingly, the diversity does not seem to follow the expected bimodality between optical type 1 and type 2 AGNs -- which are thought to be just face-on and edge-on tori. This central premise of viewing-angle dependent unified models is challenged if not dismissed by interferometric observations. The next step in understanding the AGN phenomenon -- beyond unification aspects -- is now to combine multi-scale observations with multi-scale simulations to constrain the physical processes driving the feeding and feedback of AGNs.

  13. Modelling reverberation mapping data - II. Dynamical modelling of the Lick AGN Monitoring Project 2008 data set

    NASA Astrophysics Data System (ADS)

    Pancoast, Anna; Brewer, Brendon J.; Treu, Tommaso; Park, Daeseong; Barth, Aaron J.; Bentz, Misty C.; Woo, Jong-Hak

    2014-12-01

    We present dynamical modelling of the broad-line region (BLR) for a sample of five Seyfert 1 galaxies using reverberation mapping data taken by the Lick AGN Monitoring Project in 2008. By modelling the AGN continuum light curve and Hβ line profiles directly, we are able to constrain the geometry and kinematics of the BLR and make a measurement of the black hole mass that does not depend upon the virial factor, f, needed in traditional reverberation mapping analysis. We find that the geometry of the BLR is generally a thick disc viewed close to face-on. While the Hβ emission is found to come preferentially from the far side of the BLR, the mean size of the BLR is consistent with the lags measured with cross-correlation analysis. The BLR kinematics are found to be consistent with either inflowing motions or elliptical orbits, often with some combination of the two. We measure black hole masses of log _{10}(M_ BH/M_{odot })=6.62^{+0.10}_{-0.13} for Arp 151, 7.42^{+0.26}_{-0.27} for Mrk 1310, 7.59^{+0.24}_{-0.21} for NGC 5548, 6.37^{+0.21}_{-0.16} for NGC 6814, and 6.99^{+0.32}_{-0.25} for SBS 1116+583A. The f factors measured individually for each AGN are found to correlate with inclination angle, although not with M BH, L5100, or FWHM/σ of the emission line profile.

  14. Cosmological evolution of supermassive black holes and AGN: a synthesis model for accretion and feedback .

    NASA Astrophysics Data System (ADS)

    Merloni, A.

    The growth of supermassive black holes (SMBH) through accretion is accompanied by the release of enormous amounts of energy which can either be radiated away, as happens in quasars, advected into the black hole, or disposed of in kinetic form through powerful jets, as is observed, for example, in radio galaxies. Here, I will present new constraints on the evolution of the SMBH mass function and Eddington ratio distribution, obtained from a study of AGN luminosity functions aimed at accounting for both radiative and kinetic energy output of AGN in a systematic way. First, I discuss how a refined Soltan argument leads to joint constraints on the mass-weighted average spin of SMBH and of the total mass density of high redshift (z˜ 5) and ``wandering'' black holes. Then, I will show how to describe the ``downsizing'' trend observed in the AGN population in terms of cosmological evolution of physical quantities (black hole mass, accretion rate, radiative and kinetic energy output). Finally, the redshift evolution of the AGN kinetic feedback will be briefly discussed and compared with the radiative output of the evolving SMBH population, thus providing a robust physical framework for phenomenological models of AGN feedback within structure formation.

  15. AGN Obscuration Through Dusty Infrared Dominated Flows. II. Multidimensional, Radiation-Hydrodynamics Modeling

    NASA Technical Reports Server (NTRS)

    Dorodnitsyn, Anton; Kallman, Tim; Bisno\\vatyiI-Kogan, Gennadyi

    2011-01-01

    We explore a detailed model in which the active galactic nucleus (AGN) obscuration results from the extinction of AGN radiation in a global ow driven by the pressure of infrared radiation on dust grains. We assume that external illumination by UV and soft X-rays of the dusty gas located at approximately 1pc away from the supermassive black hole is followed by a conversion of such radiation into IR. Using 2.5D, time-dependent radiation hydrodynamics simulations in a ux-limited di usion approximation we nd that the external illumination can support a geometrically thick obscuration via out ows driven by infrared radiation pressure in AGN with luminosities greater than 0:05 L(sub edd) and Compton optical depth, Tau(sub T) approx > & 1.

  16. Grand unification through gravitational effects

    SciTech Connect

    Calmet, Xavier; Hsu, Stephen D. H.; Reeb, David

    2010-02-01

    We systematically study the unification of gauge couplings in the presence of (one or more) effective dimension-5 operators cHG{sub {mu}{nu}G}{sup {mu}{nu}/}4M{sub pl}, induced into the grand unified theory by gravitational interactions at the Planck scale. These operators alter the usual condition for gauge-coupling unification, which can, depending on the Higgs content H and vacuum expectation value, result in unification at scales M{sub X} significantly different than naively expected. We find nonsupersymmetric models of SU(5) and SO(10) unification, with natural Wilson coefficients c, that easily satisfy the constraints from proton decay. Furthermore, gauge-coupling unification at scales as high as the Planck scale seems feasible, possibly hinting at simultaneous unification of gauge and gravitational interactions. In the Appendix we work out the group theoretical aspects of this scenario for SU(5) and SO(10) unified groups in detail; this material is also relevant in the analysis of nonuniversal gaugino masses obtained from supergravity.

  17. The Prevalence of Gas Outflows in Type 2 AGNs. II. 3D Biconical Outflow Models

    NASA Astrophysics Data System (ADS)

    Bae, Hyun-Jin; Woo, Jong-Hak

    2016-09-01

    We present 3D models of biconical outflows combined with a thin dust plane for investigating the physical properties of the ionized gas outflows and their effect on the observed gas kinematics in type 2 active galactic nuclei (AGNs). Using a set of input parameters, we construct a number of models in 3D and calculate the spatially integrated velocity and velocity dispersion for each model. We find that three primary parameters, i.e., intrinsic velocity, bicone inclination, and the amount of dust extinction, mainly determine the simulated velocity and velocity dispersion. Velocity dispersion increases as the intrinsic velocity or the bicone inclination increases, while velocity (i.e., velocity shifts with respect to systemic velocity) increases as the amount of dust extinction increases. Simulated emission-line profiles well reproduce the observed [O iii] line profiles, e.g., narrow core and broad wing components. By comparing model grids and Monte Carlo simulations with the observed [O iii] velocity-velocity dispersion distribution of ˜39,000 type 2 AGNs, we constrain the intrinsic velocity of gas outflows ranging from ˜500 to ˜1000 km s-1 for the majority of AGNs, and up to ˜1500-2000 km s-1 for extreme cases. The Monte Carlo simulations show that the number ratio of AGNs with negative [O iii] velocity to AGNs with positive [O iii] velocity correlates with the outflow opening angle, suggesting that outflows with higher intrinsic velocity tend to have wider opening angles. These results demonstrate the potential of our 3D models for studying the physical properties of gas outflows, applicable to various observations, including spatially integrated and resolved gas kinematics.

  18. Toward unification of multiscale modeling of the atmosphere (Vilhelm Bjerknes Medal Lecture)

    NASA Astrophysics Data System (ADS)

    Arakawa, Akio

    2010-05-01

    Vilhelm Bjerknes pointed out that a necessary condition for the rational solution of forecasting problems is a sufficiently accurate knowledge of the laws according to which one state of the atmosphere develops from another. Numerical modeling of the atmosphere has been and still is a struggle for establishing such laws. This is especially true for modeling multiscale atmospheric processes. As far as representation of deep clouds is concerned, we have two types of model physics: one highly parameterizes cloud systems as in GCMs and the other explicitly simulates individual clouds as in cloud-resolving models (CRMs). Because a variety of processes mutually interact within a cloud system, parameterization of the net effect of a cloud-system is more than taking a statistical average of the local cloud effects. Ideally, these two types of model physics should be unified so that continuous transition of model physics from on type to the other takes place as the resolution changes. Unfortunately, such a unified formulation of model physics does not exist at present. Unification of model physics in the above sense is an extremely challenging task. It requires a cloud-system model, which must be reasonably general but simple enough to be used as a framework for a parameterization. In addition, the closure assumption must be generalized far beyond those typically used in the current cumulus parameterization schemes. We will discuss some of these problems at the meeting. For practical purposes of NWP and climate simulations, however, we should also consider another route: development of a numerical model that has cloud-resolving resolution, but not necessarily everywhere. Atmospheric modeling is not alone in facing this kind of problem. Heterogeneous Multiscale Modeling (HMM, E. et al. 2007), for example, which is a new approach in applied mathematics to solve multi-physics problems, has an objective similar to ours. In HMM, the ojective is achieved by applying the

  19. Low-luminosity Blazars in Wise: A Mid-infrared View of Unification

    NASA Astrophysics Data System (ADS)

    Plotkin, Richard M.; Anderson, S. F.; Brandt, W. N.; Markoff, S.; Shemmer, O.; Wu, J.

    2012-01-01

    We use the preliminary data release from the Wide-Field Infrared Survey Explorer (WISE) to perform the first statistical study on the mid-infrared (IR) properties of a large number ( 102) of BL Lac objects -- low-luminosity Active Galactic Nuclei (AGN) with a jet beamed toward the Earth. As expected, many BL Lac objects are so highly beamed that their jet synchrotron emission dominates their IR spectral energy distributions (SEDs), and the shape of their SEDs in the IR correlates well with SED peak frequency. In other BL Lac objects, the jet is not strong enough to completely dilute the rest of the AGN, and we do not see observational signatures of the dusty torus from these weakly beamed BL Lac objects. While at odds with simple unification, the missing torus is consistent with recent suggestions that BL Lac objects are fed by radiatively inefficient accretion flows. We discuss implications on the ``nature vs. nurture" debate for FR I and FR II galaxies, and also on the standard orientation-based AGN unification model.

  20. Limitations on the recovery of the true AGN variability parameters using damped random walk modeling

    NASA Astrophysics Data System (ADS)

    Kozłowski, Szymon

    2017-01-01

    Context. The damped random walk (DRW) stochastic process is nowadays frequently used to model aperiodic light curves of active galactic nuclei (AGNs). A number of correlations between the DRW model parameters, the signal decorrelation timescale and amplitude, and the physical AGN parameters, such as the black hole mass or luminosity, have been reported. Aims: We are interested in whether or not it is plausible to correctly measure the DRW parameters from a typical ground-based survey, and, in particular, in how accurate the recovered DRW parameters are compared to the input ones. Methods: By means of Monte Carlo simulations of AGN light curves, we studied the impact of the light curve length, the source magnitude (the photometric properties of a survey), cadence, and additional light (e.g., from a host galaxy) on the DRW model parameters. Results: The most significant finding is that currently existing surveys are going to return unconstrained DRW decorrelation timescales, because typical rest-frame data do not probe long enough timescales or the white noise part of the power spectral density for DRW. The experiment length must be at least ten times longer than the true DRW decorrelation timescale, being presumably in the vicinity of one year, thus meaning the necessity for AGN light curves measuring a minimum of 10 years (rest-frame). The DRW timescales for sufficiently long light curves are typically weakly biased, and the exact bias depends on the fitting method and used priors. The DRW amplitude is mostly affected by the photometric noise (the source magnitude or the signal-to-noise ratio), cadence, and the AGN host light. Conclusions: Because the DRW parameters appear to be incorrectly determined from typically existing data, the reported correlations of the DRW variability and physical AGN parameters from other works seem unlikely to be correct. In particular, the anti-correlation of the DRW decorrelation timescale with redshift is a manifestation of the

  1. Low-scale gaugino mass unification

    SciTech Connect

    Endo, Motoi; Yoshioka, Koichi

    2008-07-15

    We study a new class of scenarios with the gaugino mass unification at the weak scale. The unification conditions are generally classified and then, the mirage gauge mediation is explored where the low-energy mass spectrum is governed by a mirage of unified gauge coupling which is seen by low-energy observers. The gaugino masses have natural and stable low-scale unification. The mass parameters of scalar quarks and leptons are given by gauge couplings but exhibit no large mass hierarchy. They are nonuniversal even when mediated at the gauge coupling unification scale. In addition, the gravitino is rather heavy and not the lightest superparticle. These facts are in contrast to existing gauge and mirage mediation models. We also present several explicit models for dynamically realizing the TeV-scale unification.

  2. NuSTAR Survey of Swift/BAT AGN as a Probe of the Unified Model

    NASA Astrophysics Data System (ADS)

    Balokovic, M.

    2015-09-01

    NuSTAR has enabled studies of the local AGN to extend into the spectral window above 10 keV with unprecedented spatial resolution and two orders of magnitude better sensitivity than any other instrument operating in that energy range. As a part of its long-term extragalactic program NuSTAR is surveying the nearby population of AGN detected at hard X-ray energies by the Swift/BAT instrument. We present results based on observations of ~100 Swift/BAT-selected Type-2 Seyferts surveyed in the first three years of NuSTAR operation. This large sample forms an atlas of the highest quality hard X-ray spectra available to date. Assuming a range of hard X-ray spectral models, phenomenological as well as physically motivated, we constrain the main spectral parameters for each source individually and test the applicability of the models on a large sample for the first time. This analysis allows us to determine distributions of the main spectral parameters related to the torus, such as the absorption column, reflection strength, and iron line equivalent width, in a well-defined population of nearby obscured AGN. More advanced models for the AGN torus allow us to investigate differences between various subsamples and interpret them within the unified model paradigm. We will discuss the implications for the structure of the torus in the local population of Type-2 Seyferts and present a comprehensive comparison of constraints derived from X-ray data and constraints from observations at other wavelengths for a relatively large sample.

  3. Constraining the fraction of Compton-thick AGN in the Universe by modelling the diffuse X-ray background spectrum

    NASA Astrophysics Data System (ADS)

    Akylas, A.; Georgakakis, A.; Georgantopoulos, I.; Brightman, M.; Nandra, K.

    2012-10-01

    This paper investigates which constraints can be placed on the fraction of Compton-thick active galactic nuclei (AGN) in the Universe from modelling the spectrum of the diffuse X-ray background (XRB). We present a model for the synthesis of the XRB that uses as input a library of AGN X-ray spectra generated by Monte Carlo simulations. This is essential to account for the Compton scattering of X-ray photons in a dense medium and the impact of that process on the spectra of heavily obscured AGN. We identify a small number of input parameters to the XRB synthesis code that encapsulate the minimum level of uncertainty in reconstructing the XRB spectrum. These are the power-law index and high-energy cutoff of the intrinsic X-ray spectra of AGN, the level of the reflection component in AGN spectra, and the fraction of Compton-thick AGN in the Universe. We then map the volume of the space allowed to these parameters by current observational determinations of the XRB spectrum in the range 3-100 keV. One of the least-constrained parameters is the fraction of Compton-thick AGN. Statistically acceptable fits to the XRB spectrum at the 68% confidence level can be obtained for Compton-thick AGN fractions in the range 5-50%. This is because of degeneracies among input parameters to the XRB synthesis code and uncertainties in the modelling of AGN spectra (e.g. level of reflection fraction). The most promising route for constraining the fraction of Compton-thick AGN in the Universe is via the direct detection of those sources in high-energy (≳ 10 keV) surveys. We show that the observed fraction of Compton-thick sources identified in the Swift/BAT serendipitous survey limits the intrinsic fraction of Compton-thick AGN, at least at low redshift, to 10-20% (68% confidence level). We also make predictions on the number density of Compton-thick sources that current and future X-ray missions are expected to discover. Testing those predictions with data will place tight constraints on

  4. First X-ray Statistical Tests for Clumpy-Torus Models: Constraints from RXTEmonitoring of Seyfert AGN

    NASA Astrophysics Data System (ADS)

    Markowitz, Alex; Krumpe, Mirko; Nikutta, R.

    2016-06-01

    In two papers (Markowitz, Krumpe, & Nikutta 2014, and Nikutta et al., in prep.), we derive the first X-ray statistical constraints for clumpy-torus models in Seyfert AGN by quantifying multi-timescale variability in line of-sight X-ray absorbing gas as a function of optical classification.We systematically search for discrete absorption events in the vast archive of RXTE monitoring of 55 nearby type Is and Compton-thin type IIs. We are sensitive to discrete absorption events due to clouds of full-covering, neutral/mildly ionized gas transiting the line of sight. Our results apply to both dusty and non-dusty clumpy media, and probe model parameter space complementary to that for eclipses observed with XMM-Newton, Suzaku, and Chandra.We detect twelve eclipse events in eight Seyferts, roughly tripling the number previously published from this archive. Event durations span hours to years. Most of our detected clouds are Compton-thin, and most clouds' distances from the black hole are inferred to be commensurate with the outer portions of the BLR or the inner regions of infrared-emitting dusty tori.We present the density profiles of the highest-quality eclipse events; the column density profile for an eclipsing cloud in NGC 3783 is doubly spiked, possibly indicating a cloud that is being tidallysheared. We discuss implications for cloud distributions in the context of clumpy-torus models. We calculate eclipse probabilities for orientation-dependent Type I/II unification schemes.We present constraints on cloud sizes, stability, and radial distribution. We infer that clouds' small angular sizes as seen from the SMBH imply 107 clouds required across the BLR + torus. Cloud size is roughly proportional to distance from the black hole, hinting at the formation processes (e.g., disk fragmentation). All observed clouds are sub-critical with respect to tidal disruption; self-gravity alone cannot contain them. External forces, such as magnetic fields or ambient pressure, are

  5. Scalar non-degeneracy and flavor unification

    SciTech Connect

    Kojima, Kentaro

    2008-05-13

    Grand unified models of the strong and electroweak forces generally predict some types of flavor unification. The flavor structure in unified theory is probed with superparticle mass spectrum observed in future particle experiments. It is shown that the generation dependence of sfermion mass non-degeneracy provides direct imprints of unification of the standard model matter multiplets. The implication from flavor-violating rare process is also discussed.

  6. JetCurry: Modeling 3D geometry of AGN jets from 2D images

    NASA Astrophysics Data System (ADS)

    Li, Kunyang; Kosak, Katie; Avachat, Sayali S.; Perlman, Eric S.

    2017-02-01

    Written in Python, JetCurry models the 3D geometry of AGN jets from 2-D images. JetCurry requires NumPy and SciPy and incorporates emcee (ascl:1303.002) and AstroPy (ascl:1304.002), and optionally uses VPython. From a defined initial part of the jet that serves as a reference point, JetCurry finds the position of highest flux within a bin of data in the image matrix and fits along the x axis for the general location of the bends in the jet. A spline fitting is used to smooth out the resulted jet stream.

  7. Nebular Emission From AGN In The Ultraviolet/Optical: Linking Observations and Theory With New Generation Spectral Models

    NASA Astrophysics Data System (ADS)

    Feltre, Anna; Charlot, S.; Gutkin, J.; Hirschmann, M.; Mignoli, M.; Calura, F.; Gilli, R.; Bongiorno, A.; NEOGAL Team

    2016-10-01

    Spectroscopic studies of AGN are powerful means of probing the physical properties of the ionized gas within them. In particular, forthcoming facilities such as JWST and the E-ELT, will provide rest-frame ultraviolet and optical spectra of the very distant AGN. To lay the groundwork for the interpretation of the revolutionary datasets, we have recently computed new photoionization models of the narrow-line emitting regions (NLR) of AGN and combined them with similar models of the nebular emission from star-forming galaxies. In this talk, I will first describe how new ultraviolet and standard optical spectral diagnostics allow one to distinguish between nuclear activity and star formation. I will then present how the nebular emission from both young stars and AGN can be coupled with a new set of cosmological hydrodynamical zoom-in simulations of massive galaxies to achieve a better understanding of black hole growth and galaxy evolution with cosmic time. I will also present an innovative Bayesian fitting code that can help us best interpret current, and future, spectro-photometric data on active galaxies. In particular, the implementation of AGN photoionization calculations within this fitting tool allows us to better understand the physical properties of the AGN NLR gas. I will conclude showing some results from a recent analysis on one of the most comprehensive set of optical spectra (from VIMOS/VLT) sampling the rest-frame ultraviolet range of 90 type 2 AGN (1.5 < z < 3), drawn from the z-COSMOS deep survey.

  8. Co-Evolution Model of AGNs and Nuclear Starbursts

    NASA Astrophysics Data System (ADS)

    Kawakatu, N.; Wada, K.

    2009-10-01

    We propose a new evolutionary model of a supermassive black hole (SMBH) and a circumnuclear disk (CND), taking into account the mass-supply from a host galaxy and the physical states of CND. In the model, two distinct accretion modes depending on gravitational stability of the CND play a key role on accreting gas to a SMBH. (i) If the CND is gravitationally unstable, energy feedback from supernovae (SNe) supports a geometrically thick, turbulent gas disk. The accretion in this mode is dominated by turbulent viscosity, and it is significantly larger than that in the mode (ii), i.e., the CND is supported by gas pressure. Once the gas supply from the host is stopped, the high accretion phase changes to the low one (mode (ii)), but there is a delay with ˜ 108 yr. Through this evolution, the gas-rich CND turns into the gas poor stellar disk. We found that not all the gas supplied from the host galaxy to the central 100 pc region accrete onto the SMBH even in the high accretion phase (mode (i)), because the part of gas is used to form stars. Moreover, a super-Eddington accretion is possible in the high accretion phase and thus the its condition is briefly discussed.

  9. Support for an Evolutionary Model of AGN Nuclei

    NASA Astrophysics Data System (ADS)

    Dultzin, D.

    2015-09-01

    I will present our recent results (2013-2015) on the role of the environment in the nuclear activity of interacting Galaxies, all of which support an evolutionary sequence in the nuclear activity. We studied close galactic pairs of similar mass in the local Universe. We analyzed 385 spectra of S S, E E, and E S pairs, and try to disentangle the role of morphology on induced activity . We compare with our own sample of bona fide isolated galaxies containing a statistically significant number of all morphological types. Our main results are in conflict with the simplest version of the so called Unified Model (UM), and suggest that high accretion rates are essential to form the Broad Line Region in active galaxies. We also investigated the structure of the dusty torus surrounding Syfert 1 and 2 nuclei, both in pairs and isolated. The results also lead to a disagreement with the UM. Finally, we present our results on the Nuclear Activity in the context of the evolution of Compact Groups of galaxies over the past 3 Gyrs. Our analysis is based on the largest multiwavelength compact group sample to-date, and the results are also in conflict with an orientation obscuration effect alone.

  10. The case for unification.

    PubMed

    Gopal-Krishna

    1995-12-05

    I investigate the issue of whether the various subclasses of radio-loud galaxies are intrinsically the same but have been classified differently mainly due to their being viewed from different directions. Evidence for the two key elements of this popular version of the "unified scheme (US)," relativistic jets and nuclear tori, is updated. The case for the torus opening angle increasing with the radio luminosity of the active galactic nucleus (AGN) is freshly argued. Radio-loud AGN are particularly suited for testing the US, since their structures and polarization properties on different scales, as well as their overall radio sizes, provide useful statistical indicators of the relative orientations of their various subclasses. I summarize recent attempts to bring under a single conceptual framework the USs developed for radio-moderate [Fanaroff-Riley type I (FRI)] and radio-powerful (FRII) AGN. By focusing on FRII radio sources, I critically examine the recent claims of conflict with the US, based on the statistics of radio-size measurements for large, presumably orientation-independent, samples with essentially complete optical identifications. Possible ways of reconciling these results, and also the ones based on very-long-baseline radio interferometry polarimetric observations, with the US are pointed out. By incorporating a highly plausible temporal evolution of radio source properties into the US, I outline a scenario that allows the median linear size of quasars to approach, or even exceed, that of radio galaxies, as samples with decreasing radio luminosity are observed. Thus, even though a number of issues remain to be fully resolved, the scope of unified models continues to expand.

  11. The case for unification.

    PubMed Central

    Gopal-Krishna

    1995-01-01

    I investigate the issue of whether the various subclasses of radio-loud galaxies are intrinsically the same but have been classified differently mainly due to their being viewed from different directions. Evidence for the two key elements of this popular version of the "unified scheme (US)," relativistic jets and nuclear tori, is updated. The case for the torus opening angle increasing with the radio luminosity of the active galactic nucleus (AGN) is freshly argued. Radio-loud AGN are particularly suited for testing the US, since their structures and polarization properties on different scales, as well as their overall radio sizes, provide useful statistical indicators of the relative orientations of their various subclasses. I summarize recent attempts to bring under a single conceptual framework the USs developed for radio-moderate [Fanaroff-Riley type I (FRI)] and radio-powerful (FRII) AGN. By focusing on FRII radio sources, I critically examine the recent claims of conflict with the US, based on the statistics of radio-size measurements for large, presumably orientation-independent, samples with essentially complete optical identifications. Possible ways of reconciling these results, and also the ones based on very-long-baseline radio interferometry polarimetric observations, with the US are pointed out. By incorporating a highly plausible temporal evolution of radio source properties into the US, I outline a scenario that allows the median linear size of quasars to approach, or even exceed, that of radio galaxies, as samples with decreasing radio luminosity are observed. Thus, even though a number of issues remain to be fully resolved, the scope of unified models continues to expand. PMID:11607607

  12. Naturality, unification, and dark matter

    SciTech Connect

    Kainulainen, Kimmo; Virkajaervi, Jussi; Tuominen, Kimmo

    2010-08-15

    We consider a model where electroweak symmetry breaking is driven by technicolor dynamics with minimal particle content required for walking coupling and saturation of global anomalies. Furthermore, the model features three additional Weyl fermions singlet under technicolor interactions, two of which provide for a one-loop unification of the standard model gauge couplings. Among these extra matter fields exists a possible candidate for weakly interacting dark matter. We evaluate the relic densities and find that they are sufficient to explain the cosmological observations and avoid the experimental limits from earth-based searches. Hence, we establish a nonsupersymmetric framework where hierarchy and naturality problems are solved, coupling constant unification is achieved, and a plausible dark matter candidate exists.

  13. Resolving the AGN and Host Emission in the Mid-infrared Using a Model-independent Spectral Decomposition

    NASA Astrophysics Data System (ADS)

    Hernán-Caballero, Antonio; Alonso-Herrero, Almudena; Hatziminaoglou, Evanthia; Spoon, Henrik W. W.; Ramos Almeida, Cristina; Díaz Santos, Tanio; Hönig, Sebastian F.; González-Martín, Omaira; Esquej, Pilar

    2015-04-01

    We present results on the spectral decomposition of 118 Spitzer Infrared Spectrograph (IRS) spectra from local active galactic nuclei (AGNs) using a large set of Spitzer/IRS spectra as templates. The templates are themselves IRS spectra from extreme cases where a single physical component (stellar, interstellar, or AGN) completely dominates the integrated mid-infrared emission. We show that a linear combination of one template for each physical component reproduces the observed IRS spectra of AGN hosts with unprecedented fidelity for a template fitting method with no need to model extinction separately. We use full probability distribution functions to estimate expectation values and uncertainties for observables, and find that the decomposition results are robust against degeneracies. Furthermore, we compare the AGN spectra derived from the spectral decomposition with sub-arcsecond resolution nuclear photometry and spectroscopy from ground-based observations. We find that the AGN component derived from the decomposition closely matches the nuclear spectrum with a 1σ dispersion of 0.12 dex in luminosity and typical uncertainties of ∼0.19 in the spectral index and ∼0.1 in the silicate strength. We conclude that the emission from the host galaxy can be reliably removed from the IRS spectra of AGNs. This allows for unbiased studies of the AGN emission in intermediate- and high-redshift galaxies—currently inaccesible to ground-based observations—with archival Spitzer/IRS data and in the future with the Mid-InfraRed Instrument of the James Webb Space Telescope. The decomposition code and templates are available at http://denebola.org/ahc/deblendIRS.

  14. Supersymmetric unification requires extra dimensions

    SciTech Connect

    Chen, Mu-Chun; Fallbacher, Maximilian; Ratz, Michael

    2013-05-23

    We discuss settings that predict precision gauge unification in the minimal supersymmetric standard model. We show that, if one requires anomaly freedom and fermion masses while demanding that unification is not an accident, only R symmetries can forbid the supersymmetric Higgs mass term {mu}. We then review the proof that R symmetries are not available in conventional grand unified theories (GUTs) and argue that this prevents natural solutions to the doublet-triplet splitting problem in four dimensions. On the other hand, higher-dimensional GUTs do not suffer from this problem. We briefly comment on an explicit string-derived model in which the {mu} and dimension five proton decay problems are solved by an order four discrete R symmetry, and comment on the higher-dimensional origin of this symmetry.

  15. Exploring the Vertical Structure of Nuclear Starburst Disks: A Possible Source of AGN Obscuration at Redshift ~ 1

    NASA Astrophysics Data System (ADS)

    Gohil, Raj; Ballantyne, David R.

    2017-01-01

    Nuclear starburst disks (NSDs) are star-forming regions that could be present at high redshift (z~1) in the vicinity of active galactic nuclei (AGNs). One dimensional analytical models by Thompson et al. (2005) show that, under certain conditions, these disks can be geometrically thick on parsec scales which make them a possible source for AGN obscuration. We construct a 2D model of NSDs where an iterative method is used to obtain vertical solutions for a given annulus. These solutions coherently satisfy the equations of energy balance, hydrostatic, radiative transfer, and the Toomre stability criteria. In comparison to 1D model, a more robust 2D calculation shows the higher scale-height at the outer part of a NSD, but predicts a lower expansion of an atmosphere at the parsec/sub-parsec scale. A total of 96 NSD models are computed under various physical conditions (black hole mass, size of a disk, and a gas fraction) in order to predict the column density distribution along a line of sight. Assuming a random distribution of input parameters, the statistics yield 59% of Type 1, 24% of Compton-thin (CTN), and 17% of Compton-thick (CTK) AGNs. The distribution of obscured AGNs fraction peaks near NH = 1023.5 cm-2. Depending on a viewing angle (θ) of a given NSD, the line of sight NH can vary from 1022 to 1028 cm-2. This supports the unification theory of AGNs as our results show an AGN can appear to be obscured by a CTK (NH > 1024 cm-2) or CTN (1022 cm-2< NH < 1024 cm-2) gas depending on a viewing angle. Using 2D structure, we show any θ is possible for CTN AGNs; however, the maximum allowed θ for CTK AGN is restricted to approximately 60 degrees.

  16. Tori, Discs, and Winds: The First Ten Years of AGN Interferometry

    NASA Astrophysics Data System (ADS)

    Hönig, Sebastian F.

    Infrared (IR) interferometry has made significant progress over the last 10 years to a level that active galactic nuclei (AGN) are now routine targets for long-baseline interferometers. Almost 50 different objects have been studied today in the near-IR and mid-IR. This allowed for detailed characterisation of the dusty environment of the actively growing black holes. It was possible to show directly that the dust must be arranged in clumps, as had been indirectly inferred from theory and unresolved observations. The dust composition seems to undergo significant evolution from galactic scales to the AGN environment, with the hottest dust close to the sublimation front being dominated by large graphite grains. While the overall distribution of the dusty mass is quite diverse from object to object, indications have been found that the dust distribution may depend on AGN luminosity, with more powerful AGN potentially showing more compact dust structures. Arguably the most exciting discovery was the fact that the bulk of the mid-IR emission in Seyfert galaxies emerges from the polar region of the AGN, which is difficult to reconcile with classical torus models. An alternative model is currently being debated that consists of a dusty disc plus a dusty wind driven by radiation pressure from the central source. This finding has major implications for our understanding of AGN unification and will become a focus of the upcoming generation of instruments at the VLTI. More recently, an application of interferometry to cosmology was proposed to measure precise geometric distances to AGN in the Hubble flow. Further exploration of this method may open up interferometry to a new scientific community.

  17. Macroscopic constraints on string unification

    SciTech Connect

    Taylor, T.R.

    1989-03-01

    The comparison of sting theory with experiment requires a huge extrapolation from the microscopic distances, of order of the Planck length, up to the macroscopic laboratory distances. The quantum effects give rise to large corrections to the macroscopic predictions of sting unification. I discus the model-independent constraints on the gravitational sector of string theory due to the inevitable existence of universal Fradkin-Tseytlin dilatons. 9 refs.

  18. Flavour democracy in strong unification

    NASA Astrophysics Data System (ADS)

    Abel, S. A.; King, S. F.

    1998-09-01

    We show that the fermion mass spectrum may naturally be understood in terms of flavour democratic fixed points in supersymmetric theories which have a large domain of attraction in the presence of ``strong unification''. Our approach provides an alternative to the approximate Yukawa texture zeroes of the Froggatt-Nielsen mechanism. We discuss a particular model based on a broken gauged SU(3)LxSU(3)R family symmetry which illustrates our approach.

  19. Inflation driven by unification energy

    NASA Astrophysics Data System (ADS)

    Hertzberg, Mark P.; Wilczek, Frank

    2017-03-01

    We examine the hypothesis that inflation is primarily driven by vacuum energy at a scale indicated by gauge coupling unification. Concretely, we consider a class of hybrid inflation models wherein the vacuum energy associated with a grand unified theory condensate provides the dominant energy during inflation, while a second "inflaton" scalar slow rolls. We show that it is possible to obtain significant tensor-to-scalar ratios while fitting the observed spectral index.

  20. AGN Obscuration Through Dusty Infrared Dominated Flows. 1; Radiation-Hydrodynamics Solution for the Wind

    NASA Technical Reports Server (NTRS)

    Dorodnitsyn, A.; Bisnovatyi-Kogan. G. S.; Kallman, T.

    2011-01-01

    We construct a radiation-hydrodynamics model for the obscuring toroidal structure in active galactic nuclei. In this model the obscuration is produced at parsec scale by a dense, dusty wind which is supported by infrared radiation pressure on dust grains. To find the distribution of radiation pressure, we numerically solve the 2D radiation transfer problem in a flux limited diffusion approximation. We iteratively couple the solution with calculations of stationary 1D models for the wind, and obtain the z-component of the velocity. Our results demonstrate that for AGN luminosities greater than 0.1 L(sub edd) external illumination can support a geometrically thick obscuration via outflows driven by infrared radiation pressure. The terminal velocity of marginally Compton-thin models (0.2 < tau(sub T) < 0.6), is comparable to or greater than the escape velocity. In Compton thick models the maximum value of the vertical component of the velocity is lower than the escape velocity, suggesting that a significant part of our torus is in the form of failed wind. The results demonstrate that obscuration via normal or failed infrared-driven winds is a viable option for the AGN torus problem and AGN unification models. Such winds can also provide an important channel for AGN feedback.

  1. Models of the Molecular Interstellar Medium in Starbursts and AGN from z=0-6

    NASA Astrophysics Data System (ADS)

    Narayanan, Desika T.; Cox, T.; Chakrabarti, S.; Dave, R.; Di Matteo, T.; Kelly, B.; Hernquist, L.; Hopkins, P.; Kulesa, C.; Li, Y.; Robertson, B.; Walker, C.

    2006-12-01

    Recent pioneering CO observations of infrared luminous galaxies and AGN at high-z allow us to study coevolution of black hole growth and star formation in galaxies during the heydey of massive galaxy formation. However, little is known concerning the physical nature of these crucial galaxies, and the relationship between the central AGN, ISM, and host galaxy properties to the observed CO emission. In order to provide a framework for an interpretation of these observations, I investigate the nature of the CO emission in starburst galaxies and quasars by combining a 3D non-LTE radiative transfer code with cosmological and galaxy merger hydrodynamic simulations. Here, I highlight recent results from these simulations. Specifically, I will discuss the following: 1. The effect of black hole growth and starbursts on CO emission patterns; 2. The role of galactic winds on CO emission morphologies and line profiles; 3. The nature of CO emission in z 6 Quasars, and how we might use this to constrain models of primordial galaxy formation.

  2. A minimal non-supersymmetric S O(10) model: Gauge coupling unification, proton decay and fermion masses

    NASA Astrophysics Data System (ADS)

    Khan, Saki

    2016-06-01

    We present a minimal renormalizable non-supersymmetric S O(10) grand unified model with a symmetry breaking sector consisting of Higgs fields in the 54H + 126H + 10H representations. This model admits a single intermediate scale associated with Pati-Salam symmetry along with a discrete parity. Spontaneous symmetry breaking, the unification of gauge couplings and proton lifetime estimates are studied in detail in this framework. Including threshold corrections self-consistently, obtained from a full analysis of the Higgs potential, we show that the model is compatible with the current experimental bound on proton lifetime. The model generally predicts an upper bound of few times 1035 yrs for proton lifetime, which is not too far from the present Super-Kamiokande limit of τp ≳ 1.29 × 1034 yrs. With the help of a Pecci-Quinn symmetry and the resulting axion, the model provides a suitable dark matter candidate while also solving the strong CP problem. The intermediate scale, MI ≈ (1013 - 1014) GeV which is also the B - L scale, is of the right order for the right-handed neutrino mass which enables a successful description of light neutrino masses and oscillations. The Yukawa sector of the model consists of only two matrices in family space and leads to a predictive scenario for quark and lepton masses and mixings. The branching ratios for proton decay are calculable with the leading modes being p → e+π0 and p →v ¯π+ . Even though the model predicts no new physics within the reach of LHC, the next generation proton decay detectors and axion search experiments have the capability to pass verdict on this minimal scenario.

  3. Petite unification: an alternative viewpoint

    SciTech Connect

    Hung, P.Q.

    1981-05-01

    It is assumed that at some distance scale, not too many orders of magnitude less than the compton wavelength of intermediate bosons W/sup + -/ and Z/sup 0/, the SU(3)/sub c/ x SU(2)/sub L/ x U(1)/sub Y/ gauge theory, characterized by three coupling constants, becomes embedded in a gauge theory G/sub S/ x G/sub W/ characterized by only two coupling constants, g/sub S/ and g/sub W/. The strong group G/sub S/ and weak group G/sub W/ are assumed each to be either simple or pseudo-simple i.e. a direct product of simple groups with identical coupling strengths. Such a possibility is caled petite unification. Any subsequent unification of the strong force with the weak at still shorter distances is left unconsidered. A building-up procedure is adopted, that is to say the available inputs from the low-energy theory SU(3)/sub c/ x SU(2)/sub L/ x U(1)/sub Y/ are used to restrict the choices of G/sub S/ and G/sub W/. The inputs used are the experimental value of sin/sup 2/theta/sub W/ and the known fermion representations. The choices of G/sub W/ are found to be quite restricted. The smallest acceptable G/sub W/ turns out to be (SU(2))/sup 4/, and the most efficient choice of a strong group is SU(4) built a la Pati and Salam, which is the simplest case for which the electroweak U(1)/sub Y/ generator is a linear combination of both G/sub S/ and G/sub W/ generators. Furthermore, leptons provide the fourth color degree of freedom achieving thus an early quark-lepton unification. The phenomenology of the minimal petite unification model SU(4) x (SU(2))/sup 4/ is examined in detail.

  4. AGN identification: what lies ahead

    NASA Astrophysics Data System (ADS)

    Fotopoulou, Sotiria

    2016-08-01

    Classification has been one the first concerns of modern astronomy, starting from stars sorted in the famous Harvard classification system and promptly followed by the morphological classification of galaxies by none other than Edwin Hubble himself (Hubble 1926). Both classification schema are essentially connected to the physics of the objects reflecting the temperature for stars and e.g. the age of the star population for galaxies. Systematic observations of galaxies have revealed the intriguing class of Active Galactic Nuclei (AGN), objects of tremendous radiation that do not share the same properties of what we now call normal galaxies. Observations have led to the definition of distinct and somewhat arbitrary categories (Seyfert galaxies, quasars, QSO, radio AGN, etc), essentially rediscovering the many faces of the same phenomenon, up until the unification of AGN (Antonucci 1993, Urry and Padovani 1995). Even after the realization that all AGN have the same engine powering their amazing radiation, astronomers are still using and refining the selection criteria within their favorite electromagnetic range in the hope to better understand the impact of the AGN phenomenon in the greater context of galaxy evolution. In the dawn of Big Data astronomy we find ourselves equipped with new tools. I will present the prospects of machine learning methods in better understanding the AGN population. Namely, I will show results from supervised learning algorithms whereby a labeled training set is used to amalgamate decision tree(s) (Fotopoulou et al., 2016) or neural network(s), and unsupervised learning where the algorithm performs clustering analysis of the full dataset in a multidimensional space identifying clusters of objects sharing potentially the same physical properties (Fotopoulou in prep.).

  5. Testing quasar unification: radiative transfer in clumpy winds

    NASA Astrophysics Data System (ADS)

    Matthews, J. H.; Knigge, C.; Long, K. S.; Sim, S. A.; Higginbottom, N.; Mangham, S. W.

    2016-05-01

    Various unification schemes interpret the complex phenomenology of quasars and luminous active galactic nuclei (AGN) in terms of a simple picture involving a central black hole, an accretion disc and an associated outflow. Here, we continue our tests of this paradigm by comparing quasar spectra to synthetic spectra of biconical disc wind models, produced with our state-of-the-art Monte Carlo radiative transfer code. Previously, we have shown that we could produce synthetic spectra resembling those of observed broad absorption line (BAL) quasars, but only if the X-ray luminosity was limited to 1043 erg s-1. Here, we introduce a simple treatment of clumping, and find that a filling factor of ˜0.01 moderates the ionization state sufficiently for BAL features to form in the rest-frame UV at more realistic X-ray luminosities. Our fiducial model shows good agreement with AGN X-ray properties and the wind produces strong line emission in, e.g., Lyα and C IV 1550 Å at low inclinations. At high inclinations, the spectra possess prominent LoBAL features. Despite these successes, we cannot reproduce all emission lines seen in quasar spectra with the correct equivalent-width ratios, and we find an angular dependence of emission line equivalent width despite the similarities in the observed emission line properties of BAL and non-BAL quasars. Overall, our work suggests that biconical winds can reproduce much of the qualitative behaviour expected from a unified model, but we cannot yet provide quantitative matches with quasar properties at all viewing angles. Whether disc winds can successfully unify quasars is therefore still an open question.

  6. InterMOD: integrated data and tools for the unification of model organism research

    PubMed Central

    Sullivan, Julie; Karra, Kalpana; Moxon, Sierra A. T.; Vallejos, Andrew; Motenko, Howie; Wong, J. D.; Aleksic, Jelena; Balakrishnan, Rama; Binkley, Gail; Harris, Todd; Hitz, Benjamin; Jayaraman, Pushkala; Lyne, Rachel; Neuhauser, Steven; Pich, Christian; Smith, Richard N.; Trinh, Quang; Cherry, J. Michael; Richardson, Joel; Stein, Lincoln; Twigger, Simon; Westerfield, Monte; Worthey, Elizabeth; Micklem, Gos

    2013-01-01

    Model organisms are widely used for understanding basic biology, and have significantly contributed to the study of human disease. In recent years, genomic analysis has provided extensive evidence of widespread conservation of gene sequence and function amongst eukaryotes, allowing insights from model organisms to help decipher gene function in a wider range of species. The InterMOD consortium is developing an infrastructure based around the InterMine data warehouse system to integrate genomic and functional data from a number of key model organisms, leading the way to improved cross-species research. So far including budding yeast, nematode worm, fruit fly, zebrafish, rat and mouse, the project has set up data warehouses, synchronized data models, and created analysis tools and links between data from different species. The project unites a number of major model organism databases, improving both the consistency and accessibility of comparative research, to the benefit of the wider scientific community. PMID:23652793

  7. Gauge-Higgs EW and grand unification

    NASA Astrophysics Data System (ADS)

    Hosotani, Yutaka

    2016-07-01

    Four-dimensional Higgs field is identified with the extra-dimensional component of gauge potentials in the gauge-Higgs unification scenario. SO(5) × U(1) gauge-Higgs EW unification in the Randall-Sundrum warped space is successful at low energies. The Higgs field appears as an Aharonov-Bohm phase 𝜃H in the fifth dimension. Its mass is generated at the quantum level and is finite. The model yields almost the same phenomenology as the standard model for 𝜃H < 0.1, and predicts Z‧ bosons around 6-10 TeV with very broad widths. The scenario is generalized to SO(11) gauge-Higgs grand unification. Fermions are introduced in the spinor and vector representations of SO(11). Proton decay is naturally forbidden.

  8. Unification of gauge, family, and flavor symmetries illustrated in gauged SU(12) models

    DOE PAGES

    Albright, Carl H.; Feger, Robert P.; Kephart, Thomas W.

    2016-04-25

    In this study, to explain quark and lepton masses and mixing angles, one has to extend the standard model, and the usual practice is to put the quarks and leptons into irreducible representations of discrete groups. We argue that discrete flavor symmetries (and their concomitant problems) can be avoided if we extend the gauge group. In the framework of SU(12) we give explicit examples of models having varying degrees of predictability obtained by scanning over groups and representations and identifying cases with operators contributing to mass and mixing matrices that need little fine- tuning of prefactors. Fitting with quark andmore » lepton masses run to the GUT scale and known mixing angles allows us to make predictions for the neutrino masses and hierarchy, the octant of the atmospheric mixing angle, leptonic CP violation, Majorana phases, and the effective mass observed in neutrinoless double beta decay.« less

  9. Unification of gauge, family, and flavor symmetries illustrated in gauged SU(12) models

    SciTech Connect

    Albright, Carl H.; Feger, Robert P.; Kephart, Thomas W.

    2016-04-25

    In this study, to explain quark and lepton masses and mixing angles, one has to extend the standard model, and the usual practice is to put the quarks and leptons into irreducible representations of discrete groups. We argue that discrete flavor symmetries (and their concomitant problems) can be avoided if we extend the gauge group. In the framework of SU(12) we give explicit examples of models having varying degrees of predictability obtained by scanning over groups and representations and identifying cases with operators contributing to mass and mixing matrices that need little fine- tuning of prefactors. Fitting with quark and lepton masses run to the GUT scale and known mixing angles allows us to make predictions for the neutrino masses and hierarchy, the octant of the atmospheric mixing angle, leptonic CP violation, Majorana phases, and the effective mass observed in neutrinoless double beta decay.

  10. Unification of Dark Matter and Dark Energy in a Modified Entropic Force Model

    NASA Astrophysics Data System (ADS)

    Chang, Zhe; Li, Ming-Hua; Li, Xin

    2011-07-01

    In Verlinde's entropic force scenario of gravity, Newton's laws and Einstein equations can be obtained from the first principles and general assumptions. However, the equipartition law of energy is invalid at very low temperatures. We show clearly that the threshold of the equipartition law of energy is related with horizon of the universe. Thus, a one-dimensional Debye (ODD) model in the direction of radius of the modified entropic force (MEF) may be suitable in description of the accelerated expanding universe. We present a Friedmann cosmic dynamical model in the ODD-MEF framework. We examine carefully constraints on the ODD-MEF model from the Union2 compilation of the Supernova Cosmology Project (SCP) collaboration, the data from the observation of the large-scale structure (LSS) and the cosmic microwave background (CMB), i.e. SNe Ia+LSS+CMB. The combined numerical analysis gives the best-fit value of the model parameters ζ ≃ 10-9 and Ωm0 = 0.224, with χ2min = 591.156. The corresponding age of the universe agrees with the result of D. Spergel et al. [J.M. Bardeen, B. Carter, and S.W. Hawking, Commun. Math. Phys. 31 (1973) 161] at 95% confidence level. The numerical result also yields an accelerated expanding universe without invoking any kind of dark energy. Taking ζ(≡ 2πωD/H0) as a running parameter associated with the structure scale r, we obtain a possible unified scenario of the asymptotic flatness of the radial velocity dispersion of spiral galaxies, the accelerated expanding universe and the Pioneer 10/11 anomaly in the entropic force framework of Verlinde.

  11. The 'Supercritical Pile' GRB Model: Afterglows and GRB, XRR, XRF Unification

    NASA Technical Reports Server (NTRS)

    Kazanas, D.

    2007-01-01

    We present the general notions and observational consequences of the "Supercritical Pile" GRB model; the fundamental feature of this model is a detailed process for the conversion of the energy stored in relativistic protons in the GRB Relativistic Blast Waves (RBW) into relativistic electrons and then into radiation. The conversion is effected through the $p \\, \\gamma \\rightarrow p \\, e circumflex + e circumflex -$ reaction, whose kinematic threshold is imprinted on the GRB spectra to provide a peak of their emitted luminosity at energy \\Ep $\\sim 1$ MeV in the lab frame. We extend this model to include, in addition to the (quasi--)thermal relativistic post-shock protons an accelerated component of power law form. This component guarantees the production of $e circumflex +e circumflex- - $pairs even after the RBW has slowed down to the point that its (quasi-) thermal protons cannot fulfill the threshold of the above reaction. We suggest that this last condition marks the transition from the prompt to the afterglow GRB phase. We also discuss conditions under which this transition is accompanied by a significant drop in the flux and could thus account for several puzzling, recent observations. Finally, we indicate that the same mechanism applied to the late stages of the GRB evolution leads to a decrease in \\Ep $\\propto \\Gamma circumflex 2(t)\\propto t circumflex {-3/4}$, a feature amenable to future observational tests.

  12. Unification of Fundamental Forces

    NASA Astrophysics Data System (ADS)

    Salam, Abdus; Taylor, Foreword by John C.

    2005-10-01

    Foreword John C. Taylor; 1. Unification of fundamental forces Abdus Salam; 2. History unfolding: an introduction to the two 1968 lectures by W. Heisenberg and P. A. M. Dirac Abdus Salam; 3. Theory, criticism, and a philosophy Werner Heisenberg; 4. Methods in theoretical physics Paul Adrian Maurice Dirac.

  13. ACTIVE GALACTIC NUCLEI AS MAIN CONTRIBUTORS TO THE ULTRAVIOLET IONIZING EMISSIVITY AT HIGH REDSHIFTS: PREDICTIONS FROM A {Lambda}-CDM MODEL WITH LINKED AGN/GALAXY EVOLUTION

    SciTech Connect

    Giallongo, E.; Menci, N.; Fiore, F.; Castellano, M.; Fontana, A.; Grazian, A.; Pentericci, L.

    2012-08-20

    We have evaluated the contribution of the active galactic nuclei (AGN) population to the ionization history of the universe based on a semi-analytic model of galaxy formation and evolution in the cold dark matter cosmological scenario. The model connects the growth of black holes and of the ensuing AGN activity to galaxy interactions. In the model we have included a self-consistent physical description of the escape of ionizing UV photons; this is based on the blast-wave model for the AGN feedback we developed in a previous paper to explain the distribution of hydrogen column densities in AGNs of various redshifts and luminosities, due to absorption by the host galaxy gas. The model predicts UV luminosity functions for AGNs that are in good agreement with those derived from the observations especially at low and intermediate redshifts (z {approx} 3). At higher redshifts (z > 5), the model tends to overestimate the data at faint luminosities. Critical biases in both the data and in the model are discussed to explain such apparent discrepancies. The predicted hydrogen photoionization rate as a function of redshift is found to be consistent with that derived from the observations. All of the above suggests that we should reconsider the role of the AGNs as the main driver of the ionization history of the universe.

  14. Obscured accretion from AGN surveys

    NASA Astrophysics Data System (ADS)

    Vignali, Cristian

    2014-07-01

    Recent models of super-massive black hole (SMBH) and host galaxy joint evolution predict the presence of a key phase where accretion, traced by obscured Active Galactic Nuclei (AGN) emission, is coupled with powerful star formation. Then feedback processes likely self-regulate the SMBH growth and quench the star-formation activity. AGN in this important evolutionary phase have been revealed in the last decade via surveys at different wavelengths. On the one hand, moderate-to-deep X-ray surveys have allowed a systematic search for heavily obscured AGN, up to very high redshifts (z~5). On the other hand, infrared/optical surveys have been invaluable in offering complementary methods to select obscured AGN also in cases where the nuclear X-ray emission below 10 keV is largely hidden to our view. In this review I will present my personal perspective of the field of obscured accretion from AGN surveys.

  15. Hidden SUSY from precision gauge unification

    NASA Astrophysics Data System (ADS)

    Krippendorf, Sven; Nilles, Hans Peter; Ratz, Michael; Winkler, Martin Wolfgang

    2013-08-01

    We revisit the implications of naturalness and gauge unification in the minimal supersymmetric standard model. We find that precision unification of the couplings in connection with a small μ parameter requires a highly compressed gaugino pattern as it is realized in mirage mediation. Due to the small mass difference between the gluino and lightest supersymmetric particle (LSP), collider limits on the gluino mass are drastically relaxed. Without further assumptions, the relic density of the LSP is very close to the observed dark matter density due to coannihilation effects.

  16. VizieR Online Data Catalog: AGN torus models. SED library (Siebenmorgen+, 2015)

    NASA Astrophysics Data System (ADS)

    Siebenmorgen, R.; Heymann, F.; Efstathiou, A.

    2015-08-01

    There are 3600 ASCII tables files in two columns format. The first is the wavelength in microns, the second column is the flux in Jy. SEDs are computed for AGNs at a distance of 50Mpc and a luminosity of 1011L⊙. The file names include the five basic model parameters: a) th: The viewing angle corresponding to bins at 86, 80, 73, 67, 60, 52, 43, 33, and 19 degree measured from the pole (z-axis). thx= th1 ,.., th9 b) R : The inner radius of the dusty torus. R= 300, 514, 772, 1000, 1545 in units: (10^15 cm) c) Vc: The cloud volume filling factor. Vc= 1.5, 7.7, 38.5, 77.7 (%). d) Ac: The optical depth (in V) of the individual clouds. Ac= 0, 4.5, 13.5, 45. e) Ad: The optical depth (in V) of the disk midplane. Ad= 0, 30, 100, 300, 1000. Example: File notation. RxxxxVcxxxAcxxxx_Adxxxx.thx R1545Vc777Ac0135_Ad1000.th9 (2 data files).

  17. Kinetic Modeling of Electron Conduction-Driven Microinstabilities and Their Relevance for AGN Feedback

    NASA Astrophysics Data System (ADS)

    Roberg-Clark, Gareth; Swisdak, M.; Reynolds, Christopher S.; Drake, James

    2016-04-01

    Since the Intracluster Medium (ICM) is a weakly collisional plasma, the standard Spitzer conduction rate (which relies on collisionality) does not necessarily describe the transport of heat in clusters. In addition, many plasma microinstabilities become unstable at high beta since the magnetic field is easily pliable in the presence of induced pressure anisotropies. These properties imply that the true rate of conduction in an ICM-like plasma could be highly dependent on small-scale effects. We perform 2D kinetic Particle-In-Cell simulations and derive an analytic theory of a conduction-driven electron microinstability present in high-beta collisionless plasmas. We find that scattering by electromagnetic waves significantly reduces the conductive heat flux of electrons in our model. Our results have implications for 1) cool-core clusters in which AGN feedback may play a crucial role in maintaing overall thermodynamic stability, 2) heat flux suppression and scattering by other microinstabilities and 3) basic plasma physics questions that up until this point have not been explored fully.

  18. Search for a Realistic Orbifold Grand Unification

    SciTech Connect

    Kawamura, Yoshiharu

    2008-05-13

    We review the prototype model of a grand unified theory on the orbifold S{sup 1}/Z{sub 2} and discuss topics related to the choice of boundary conditions; the dynamical rearrangement of gauge symmetry and the equivalence classes of BCs. We explore a family unification scenario by orbifolding.

  19. The sharpest view of the local AGN population at mid-infrared wavelengths

    NASA Astrophysics Data System (ADS)

    Asmus, Daniel; Hönig, Sebastian F.; Gandhi, Poshak; Smette, Alain; Duschl, Wolfgang J.

    2014-07-01

    We present the largest mid-infrared (MIR) atlas of active galactic nuclei at sub-arcsec spatial scales containing 253 objects with a median redshift of 0.016. It comprises all available ground-based high-angular resolution MIR observations performed to date with 8-meter class telescopes and includes 895 photometric measurements. All types of AGN are present in the atlas, which also includes 80 per cent of the 9-month BAT AGN sample. Therefore, this atlas and its subsamples are very well-suited for AGN unification studies. A first application of the atlas is the extension of the MIR-X-ray luminosity correlation for AGN.

  20. Intermediate inclinations of type 2 Coronal-Line Forest AGN

    NASA Astrophysics Data System (ADS)

    Rose, Marvin; Elvis, Martin; Crenshaw, Michael; Glidden, Ana

    2015-07-01

    Coronal-Line Forest Active Galactic Nuclei (CLiF AGN) are remarkable in the sense that they have a rich spectrum of dozens of coronal emission lines (e.g. [Fe VII], [Fe X] and [Ne V]) in their spectra. Rose, Elvis & Tadhunter suggest that the inner obscuring torus wall is the most likely location of the coronal line region in CLiF AGN, and the unusual strength of the forbidden high-ionization lines is due to a specific AGN-torus inclination angle. Here, we test this suggestion using mid-IR colours (4.6-22 μm) from the Wide-Field Infrared Survey Explorer for the CLiF AGN. We use the Fischer et al. result that showed that as the AGN-torus inclination becomes more face on, the Spitzer 5.5-30 μm colours become bluer. We show that the [W2-W4] colours for the CLiF AGN (<[W2-W4]> = 5.92 ± 0.12) are intermediate between Sloan Digital Sky Survey (SDSS) type 1 (<[W2-W4]> = 5.22 ± 0.01) and type 2 AGN (<[W2-W4]> = 6.35 ± 0.03). This implies that the AGN-torus inclinations for the CLiF AGN are indeed intermediate, supporting the work of Rose, Elvis & Tadhunter. The confirmed relation between CLiF AGN and their viewing angle shows that CLiF AGN may be useful for our understanding of AGN unification.

  1. THE SPATIAL CLUSTERING OF ROSAT ALL-SKY SURVEY AGNs. II. HALO OCCUPATION DISTRIBUTION MODELING OF THE CROSS-CORRELATION FUNCTION

    SciTech Connect

    Miyaji, Takamitsu; Aceves, Hector; Krumpe, Mirko; Coil, Alison L.

    2011-01-10

    This is the second paper of a series that reports on our investigation of the clustering properties of active galactic nuclei (AGNs) in the ROSAT All-Sky Survey (RASS) through cross-correlation functions (CCFs) with Sloan Digital Sky Survey (SDSS) galaxies. In this paper, we apply the Halo Occupation Distribution (HOD) model to the CCFs between the RASS broad-line AGNs with SDSS luminous red galaxies (LRGs) in the redshift range 0.16 < z < 0.36 that was calculated in Paper I. In our HOD modeling approach, we use the known HOD of LRGs and constrain the HOD of the AGNs by a model fit to the CCF. For the first time, we are able to go beyond quoting merely a 'typical' AGN host halo mass, M{sub h}, and model the full distribution function of AGN host dark matter halos. In addition, we are able to determine the large-scale bias and the mean M{sub h} more accurately. We explore the behavior of three simple HOD models. Our first model (Model A) is a truncated power-law HOD model in which all AGNs are satellites. With this model, we find an upper limit to the slope ({alpha}) of the AGN HOD that is far below unity. The other two models have a central component, which has a step function form, where the HOD is constant above a minimum mass, without (Model B) or with (Model C) an upper mass cutoff, in addition to the truncated power-law satellite component, similar to the HOD that is found for galaxies. In these two models we find that the upper limits on {alpha} are still below unity, with {alpha} {approx}< 0.95 and {alpha} {approx}< 0.84 for Models B and C, respectively. Our analysis suggests that the satellite AGN occupation increases slower than, or may even decrease with, M{sub h}, in contrast to the satellite HODs of luminosity-threshold samples of galaxies, which, in contrast, grow approximately as (N{sub s}) {proportional_to} M{sup {alpha}}{sub h} with {alpha} {approx} 1. These results are consistent with observations that the AGN fraction in groups and clusters

  2. The Role of AGN Feedback in the Evolution of Seyfert Galaxies

    NASA Astrophysics Data System (ADS)

    Mueller-Sanchez, F.; Malkan, M.; Hicks, E.; Davies, R.

    2014-10-01

    Adaptive optics integral-field observations of Seyfert Galaxies have recently revealed clear evidence of AGN-driven outflows of ionized gas. By resolving the inner 10-20 parsecs, we are successfully modeling the geometry and kinematics of the outflows in 3D. The model parameters are used to estimate mechanical feedback from the AGN and test unification models. The mass outflow rates are 2-3 orders of magnitude greater than the accretion rates, but they are comparable to the estimated inflow rates to the central 10-25 pc, suggesting that the outflows may remove a considerable amount of the infalling gas before it reaches the accretion disk. The outflows seem to form two distinct groups which differ by outflow power variations with radio flux. While powerful outflows (with kinetic powers > 1.0% Lbol) are observed in objects with extended radio jets, in the other AGN - in which the outflow power is less than 0.1% Lbol - the radio jet is weak and compact.

  3. The dusty heart of nearby active galaxies. II. From clumpy torus models to physical properties of dust around AGN

    NASA Astrophysics Data System (ADS)

    Hönig, S. F.; Kishimoto, M.

    2010-11-01

    With the possibilities of high spatial resolution imaging and spectroscopy as well as infrared (IR) interferometry, the dusty environments (= “dusty torus”) of active galactic nuclei (AGN) are now in reach of observations. Following our Paper I on ground-based mid-IR spectro-photometry, we present an upgrade to our radiative transfer model of three-dimensional clumpy dust tori. The upgrade with respect to earlier work concerns an improved handling of the diffuse radiation field in the torus, which is approximated by a statistical approach. The models are presented as tools to translate classical and interferometric observations into characteristic properties of the dust distribution. We compare model spectral energy distributions (SEDs) for different chemical and grain-size compositions of the dust and find that clouds with standard interstellar matter (ISM) dust and optical depth τV ~ 50 appear in overall agreement with observed IR SEDs. By studying parameter dependencies, it is shown that type 1 AGN SEDs, in particular the mid-IR spectral index, can be used to constrain the radial dust cloud distribution power law index a, while other parameters are more difficult to assess using SEDs only. Interferometry adds important additional information for modeling when it is interpreted concurrently with the SED. Although type 2 AGN can in principle be used to constrain model parameters as well, obscuration effects make the analysis more ambiguous. We propose a simple, interferometry-based method to distinguish between “compact” and “extended” radial dust distributions without detailed modeling of the data and introduce a way to easily determine individual or sample average model parameters using the observed optical depth in the silicate feature and the mid-IR spectral index.

  4. Accretion Timescales from Kepler AGN

    NASA Astrophysics Data System (ADS)

    Kasliwal, Vishal P.; Vogeley, Michael S.; Richards, Gordon T.

    2015-01-01

    We constrain AGN accretion disk variability mechanisms using the optical light curves of AGN observed by Kepler. AGN optical fluxes are known to exhibit stochastic variations on timescales of hours, days, months and years. The excellent sampling properties of the original Kepler mission - high S/N ratio (105), short sampling interval (30 minutes), and long sampling duration (~ 3.5 years) - allow for a detailed examination of the differences between the variability processes present in various sub-types of AGN such as Type I and II Seyferts, QSOs, and Blazars. We model the flux data using the Auto-Regressive Moving Average (ARMA) representation from the field of time series analysis. We use the Kalman filter to determine optimal mode parameters and use the Akaike Information Criteria (AIC) to select the optimal model. We find that optical light curves from Kepler AGN cannot be fit by low order statistical models such as the popular AR(1) process or damped random walk. Kepler light curves exhibit complicated power spectra and are better modeled by higher order ARMA processes. We find that Kepler AGN typically exhibit power spectra that change from a bending power law (PSD ~ 1/fa) to a flat power spectrum on timescales in the range of ~ 5 - 100 days consistent with the orbital and thermal timescales of a typical 107 solar mass black hole.

  5. X-Ray Absorbed, Broad-Lined, Red AGN and the Cosmic X-Ray Background

    NASA Technical Reports Server (NTRS)

    Mushotzky, Richard (Technical Monitor); Wilkes, Belinda

    2005-01-01

    detectable in the typically low S/N data of X-ray surveys. Even if absorption is present in only half of the population, the large number of 'red' AGN suggests a development of unification models, where the continuum source is surrounded, over a substantial solid angle, by the wind or atmosphere of an accretion disk/torus. X-ray observations of such AGN not only provide a check on the presence of absorption, but also a unique probe of the absorbing material. Improved information on their space density, in particular as a function of redshift, will soon be provided by Spitzer-Chandra wide area surveys, allowing better estimates of both the importance of red AGN to the full AGN population and their contribution to the CXRB.

  6. Ionized Absorbers in AGN

    NASA Technical Reports Server (NTRS)

    Mathur, S.

    1999-01-01

    As a part of this program, we observed three AGN:PKS2251 + 113, PG0043 = 039 and PLH909. Two objects show signatures of absorbtion in their UV spectra. Based on our earlier modeling of X-ray warm absorbents, we expected to observe X-ray observation in these objects. The third, PLH909, is known to have soft excess in EINSTEIN data. Attachment: "Exploratory ASCA observation of broad absorption line quasi-stellar objects".

  7. AGN feedback and the origin of the α enhancement in early-type galaxies – insights from the GAEA model

    NASA Astrophysics Data System (ADS)

    De Lucia, Gabriella; Fontanot, Fabio; Hirschmann, Michaela

    2017-03-01

    We take advantage of our recently published model for GAlaxy Evolution and Assembly (GAEA) to study the origin of the observed correlation between [α/Fe] and galaxy stellar mass. In particular, we analyse the role of radio-mode active galactic nuclei (AGN) feedback, which recent work has identified as a crucial ingredient to reproduce observations. In GAEA, this process introduces the observed trend of star formation histories extending over shorter time-scales for more massive galaxies, but does not provide a sufficient condition to reproduce the observed α enhancements of massive galaxies. In the framework of our model, this is possible only by assuming that any residual star formation is truncated for galaxies more massive than 1010.5 M⊙. This results, however, in even shorter star formation time-scales for the most massive galaxies, which translate in total stellar metallicities significantly lower than observed. Our results demonstrate that (i) trends of [α/Fe] ratios cannot be simply converted into relative time-scale indicators; and (ii) AGN feedback cannot explain alone the positive correlation between [α/Fe] and galaxy mass/velocity dispersion. Reproducing simultaneously the mass-metallicity relation and the α enhancements observed pose a challenge for hierarchical models, unless more exotic solutions are adopted such as metal-rich winds or a variable initial mass function.

  8. Gauge-Higgs EW and Grand Unification

    NASA Astrophysics Data System (ADS)

    Hosotani, Yutaka

    Four-dimensional Higgs field is identified with the extra-dimensional component of gauge potentials in the gauge-Higgs unifiation scenario. SO(5) × U(1) gauge-Higgs EW unification in the Randall-Sundrum warped space is successful at low energies. The Higgs field appears as an Aharonov-Bohm phase θH in the fifth dimension. Its mass is generated at the quantum level and is finite. The model yields almost the same phenomenology as the standard model for θH < 0.1, and predicts Z' bosons around 6-10 TeV with very broad widths. The scenario is generalized to SO(11) gauge-Higgs grand unification. Fermions are introduced in the spinor and vector representations of SO(11). Proton decay is naturally forbidden.

  9. Probing AGN Accretion Physics through AGN Variability: Insights from Kepler

    NASA Astrophysics Data System (ADS)

    Kasliwal, Vishal Pramod

    Active Galactic Nuclei (AGN) exhibit large luminosity variations over the entire electromagnetic spectrum on timescales ranging from hours to years. The variations in luminosity are devoid of any periodic character and appear stochastic. While complex correlations exist between the variability observed in different parts of the electromagnetic spectrum, no frequency band appears to be completely dominant, suggesting that the physical processes producing the variability are exceedingly rich and complex. In the absence of a clear theoretical explanation of the variability, phenomenological models are used to study AGN variability. The stochastic behavior of AGN variability makes formulating such models difficult and connecting them to the underlying physics exceedingly hard. We study AGN light curves serendipitously observed by the NASA Kepler planet-finding mission. Compared to previous ground-based observations, Kepler offers higher precision and a smaller sampling interval resulting in potentially higher quality light curves. Using structure functions, we demonstrate that (1) the simplest statistical model of AGN variability, the damped random walk (DRW), is insufficient to characterize the observed behavior of AGN light curves; and (2) variability begins to occur in AGN on time-scales as short as hours. Of the 20 light curves studied by us, only 3-8 may be consistent with the DRW. The structure functions of the AGN in our sample exhibit complex behavior with pronounced dips on time-scales of 10-100 d suggesting that AGN variability can be very complex and merits further analysis. We examine the accuracy of the Kepler pipeline-generated light curves and find that the publicly available light curves may require re-processing to reduce contamination from field sources. We show that while the re-processing changes the exact PSD power law slopes inferred by us, it is unlikely to change the conclusion of our structure function study-Kepler AGN light curves indicate

  10. Quasar emission lines as probes of orientation: implications for disc wind geometries and unification

    NASA Astrophysics Data System (ADS)

    Matthews, J. H.; Knigge, C.; Long, K. S.

    2017-01-01

    The incidence of broad absorption lines (BALs) in quasar samples is often interpreted in the context of a geometric unification model consisting of an accretion disc and an associated outflow. We use the the Sloan Digital Sky Survey (SDSS) quasar sample to test this model by examining the equivalent widths (EWs) of C IV 1550 Å, Mg II 2800 Å, [O III] 5007 Å and C III] 1909 Å. We find that the emission line EW distributions in BAL and non-BAL quasars are remarkably similar - a property that is inconsistent with scenarios in which a BAL outflow rises equatorially from a geometrically thin, optically thick accretion disc. We construct simple models to predict the distributions from various geometries; these models confirm the above finding and disfavour equatorial geometries. We show that obscuration, line anisotropy and general relativistic effects on the disc continuum are unlikely to hide an EW inclination dependence. We carefully examine the radio and polarisation properties of BAL quasars. Both suggest that they are most likely viewed (on average) from intermediate inclinations, between type 1 and type 2 AGN. We also find that the low-ionization BAL quasars in our sample are not confined to one region of `Eigenvector I' parameter space. Overall, our work leads to one of the following conclusions, or some combination thereof: (i) the continuum does not emit like a geometrically thin, optically thick disc; (ii) BAL quasars are viewed from similar angles to non-BAL quasars, i.e. low inclinations; (iii) geometric unification does not explain the fraction of BALs in quasar samples.

  11. Unification of coupling constants, dimension 6 operators and the spectral action

    NASA Astrophysics Data System (ADS)

    Devastato, Agostino; Lizzi, Fedele; Flores, Carlos Valcárcel; Vassilevich, Dmitri

    2015-03-01

    We investigate whether inclusion of dimension 6 terms in the Standard Model Lagrangian may cause the unification of the coupling constants at a scale comprised between 1014 and 1017 GeV. Particular choice of the dimension 6 couplings is motivated by the spectral action. Given the theoretical and phenomenological constraints, as well as recent data on the Higgs mass, we find that the unification is indeed possible, with a lower unification scale slightly favored.

  12. Yukawa Unification Predictions with Effective ``Mirage'' Mediation

    NASA Astrophysics Data System (ADS)

    Anandakrishnan, Archana; Raby, Stuart

    2013-11-01

    In this Letter we analyze the consequences, for the LHC, of gauge and third family Yukawa coupling unification with a particular set of boundary conditions defined at the grand unified theory (GUT) scale, which we characterize as effective “mirage” mediation. We perform a global χ2 analysis including the observables MW, MZ, GF, αem-1, αs(MZ), Mt, mb(mb), Mτ, BR(B→Xsγ), BR(Bs→μ+μ-), and Mh. The fit is performed in the minimal supersymmetric standard model in terms of 10 GUT scale parameters, while tan⁡β and μ are fixed at the weak scale. We find good fits to the low energy data and a supersymmetry spectrum which is dramatically different than previously studied in the context of Yukawa unification.

  13. Yukawa unification predictions with effective "mirage" mediation.

    PubMed

    Anandakrishnan, Archana; Raby, Stuart

    2013-11-22

    In this Letter we analyze the consequences, for the LHC, of gauge and third family Yukawa coupling unification with a particular set of boundary conditions defined at the grand unified theory (GUT) scale, which we characterize as effective "mirage" mediation. We perform a global χ2 analysis including the observables M(W), M(Z), G(F), α(em)(-1), α(s)(M(Z)), M(t), m(b)(m(b)), M(τ), BR(B→X(s)γ), BR(B(s)→μ(+)μ(-)), and M(h). The fit is performed in the minimal supersymmetric standard model in terms of 10 GUT scale parameters, while tanβ and μ are fixed at the weak scale. We find good fits to the low energy data and a supersymmetry spectrum which is dramatically different than previously studied in the context of Yukawa unification.

  14. Unification and new particles at the LHC

    NASA Astrophysics Data System (ADS)

    Arkani-Hamed, Nima; D'Agnolo, Raffaele Tito; Low, Matthew; Pinner, David

    2016-11-01

    Precision gauge coupling unification is one of the primary quantitative successes of low energy or split supersymmetry. Preserving this success puts severe restrictions on possible matter and gauge sectors that might appear at collider-accessible energies. In this work we enumerate new gauge sectors which are compatible with unification, consisting of horizontal gauge groups acting on vector-like matter charged under the Standard Model. Interestingly, almost all of these theories are in the supersymmetric conformal window at high energies and confine quickly after the superpartners are decoupled. For a range of scalar masses compatible with both moderately tuned and minimally split supersymmetry, the confining dynamics happen at the multi-TeV scale, leading to a spectrum of multiple spin-0 and spin-1 resonances accessible to the LHC, with unusual quantum numbers and striking decay patterns.

  15. Grand unification and low scale implications: D₂ parity for unification and neutrino masses

    SciTech Connect

    Tavartkiladze, Zurab

    2014-01-01

    The Grand Unified SU(5)-SU(5)´ model, augmented with D₂ Parity, is considered. The latter play crucial role for phenomenology. The model has several novel properties and gives interesting phenomenological implications. The charged leptons together with right handed (or sterile) neutrinos emerge es composite states. Within considered scenario, we study the charged fermion and neutrino mass generation. Moreover, we show that the model gives successful gauge coupling unification.

  16. Last workshop on grand unification

    SciTech Connect

    Frampton, P.H. . Dept. of Physics and Astronomy)

    1991-01-01

    The presentations at the workshop alternated between experiment and theory in the traditional manner. Let me introduce first all the experimental topics. For the proton decay experiments, their present status was provided by Ayres, Ernwein, Gajewski and Totsuka for the Soudan, Frejus, IMB and Kamioka groups respectively. Massive neutrinos were reviewed by Robertson, solar neutrinos by Bahcall, and double beta decay by Avignone. Monopole searches were covered by Barish. Other experimental talks concerned both astrophysics and the Standard Model. In astrophysics, Perlmutter presented the possible discovery of a sub- millisecond pulsar in supernova 1987A and Sadoulet outlined a program to search for dark matter. Within the Standard Model, Matthews reported the recent discovery of Z{sup 0} particle decays at SLC and Dehmelt described his high-accuracy measurement of (g-2){sub c}. The theoretical talks were on GUTs, extensions of the Standard Model, general relativity and strings, and theoretical astrophysics and cosmology. Langacker talked on grand unification, proton decay and neutrino masses.

  17. MUC (Memory, Unification, Control) and beyond

    PubMed Central

    Hagoort, Peter

    2013-01-01

    A neurobiological model of language is discussed that overcomes the shortcomings of the classical Wernicke-Lichtheim-Geschwind model. It is based on a subdivision of language processing into three components: Memory, Unification, and Control. The functional components as well as the neurobiological underpinnings of the model are discussed. In addition, the need for extension of the model beyond the classical core regions for language is shown. The attention network and the network for inferential processing are crucial to realize language comprehension beyond single word processing and beyond decoding propositional content. It is shown that this requires the dynamic interaction between multiple brain regions. PMID:23874313

  18. Star Formation and AGN activity of X-ray selected AGN host galaxies in the Chandra-COSMOS Legacy Survey

    NASA Astrophysics Data System (ADS)

    Suh, Hyewon

    2017-01-01

    One of the ongoing issues for understanding the galaxy formation and evolution is how active galactic nuclei (AGNs) affect the growth of their host galaxies. We investigate the correlations between AGN activity and star formation properties of a large sample of ~3700 X-ray selected AGNs over a wide range of luminosities (42 < log Lx < 45) up to z~5 in the Chandra-COSMOS Legacy Survey. We perform a multi-component modeling from the far-infrared, when available, to the near-UV using AGN emission from the big-blue-bump (for Type 1 AGNs), a nuclear dust torus model, a galaxy model and a starburst component for the spectral energy distributions (SEDs). Through detailed analysis of SEDs, we derive AGN host galaxy properties, such as stellar masses, star formation rates (SFRs), and AGN luminosities. We find that AGN host galaxies have, on average, similar SFRs compared to the normal star-forming main sequence galaxies, suggesting no significant enhancement or quenching of star formation. The average SFR of AGN host galaxies shows a flat distribution in bins of AGN luminosity, consistent with recent ideas that the shorter variability timescale of AGN compared to star formation can lead to a flat relationship between the SFR and black hole accretion rates. Our results suggest that both star formation and nuclear activity in the majority of AGN host galaxies might be driven more by internal secular processes at z<3, implying that they have substantially grown at much earlier epoch.

  19. Supersymmetry and supergravity: Phenomenology and grand unification

    SciTech Connect

    Arnowitt, R. |; Nath, P.

    1993-12-31

    A survey is given of supersymmetry and supergravity and their phenomenology. Some of the topics discussed are the basic ideas of global supersymmetry, the minimal supersymmetric Standard Model (MSSM) and its phenomenology, the basic ideas of local supersymmetry (supergravity), grand unification, supersymmetry breaking in supergravity grand unified models, radiative breaking of SU(2) {times} U(1), proton decay, cosmological constraints, and predictions of supergravity grand unified models. While the number of detailed derivations are necessarily limited, a sufficient number of results are given so that a reader can get a working knowledge of this field.

  20. Multi-faceted AGN

    NASA Astrophysics Data System (ADS)

    Farrar, Glennys R.; Chen, Yanping; Dai, Yuxiao; Zaw, Ingyin

    2016-08-01

    An interesting question is how frequently an object is an AGN by multiple different criteria — e.g., is simultaneously a narrow-line optical AGN and an X-ray or radio AGN, possibly as a function of luminosities in the various wavebands and perhaps host galaxy type. Answering such questions quantitatively has been difficult up to now because of the lack of a complete, uniformly selected optical AGN catalog. Here we report first results of such an analysis, using the new, all-sky catalog of uniformly selected optical AGNs from Zaw, Chen and Farrar (2016), the Swift-BAT 70-month catalog of X-ray AGN (Baumgartner et al., 2013), and the van Velzen et al. (2012) catalog of radio AGN.

  1. The Lack of Torus Emission from BL Lacertae Objects: An Infrared View of Unification with WISE

    NASA Astrophysics Data System (ADS)

    Plotkin, Richard M.; Anderson, Scott F.; Brandt, W. N.; Markoff, Sera; Shemmer, Ohad; Wu, Jianfeng

    2012-02-01

    We use data from the Wide-Field Infrared Survey Explorer (WISE) to perform a statistical study on the mid-infrared (IR) properties of a large number (~102) of BL Lac objects—low-luminosity active galactic nuclei (AGNs) with a jet beamed toward the Earth. As expected, many BL Lac objects are so highly beamed that their jet synchrotron emission dominates their IR spectral energy distributions. In other BL Lac objects, however, the jet is not strong enough to completely dilute the rest of the AGN emission. We do not see observational signatures of the dusty torus from these weakly beamed BL Lac objects. The lack of observable torus emission is consistent with suggestions that BL Lac objects are fed by radiatively inefficient accretion disks. Implications for the "nature versus nurture" debate for FR I and FR II radio galaxies are briefly discussed. Our study supports the notion that, beyond orientation, accretion rate plays an important role in AGN unification.

  2. An Axisymmetric Hydrodynamical Model for the Torus Wind in AGN. 2; X-ray Excited Funnel Flow

    NASA Technical Reports Server (NTRS)

    Dorodnitsyn, A.; Kallman, T.; Proga, D.

    2008-01-01

    We have calculated a series of models of outflows from the obscuring torus in active galactic nuclei (AGN). Our modeling assumes that the inner face of a rotationally supported torus is illuminated and heated by the intense X-rays from the inner accretion disk and black hole. As a result of such heating a strong biconical outflow is observed in our simulations. We calculate 3-dimensional hydrodynamical models, assuming axial symmetry, and including the effects of X-ray heating, ionization, and radiation pressure. We discuss the behavior of a large family of these models, their velocity fields, mass fluxes and temperature, as functions of the torus properties and X-ray flux. Synthetic warm absorber spectra are calculated, assuming pure absorption, for sample models at various inclination angles and observing times. We show that these models have mass fluxes and flow speeds which are comparable to those which have been inferred from observations of Seyfert 1 warm absorbers, and that they can produce rich absorption line spectra.

  3. Theoretical modelling of the AGN iron line vs. continuum time-lags in the lamp-post geometry

    NASA Astrophysics Data System (ADS)

    Epitropakis, A.; Papadakis, I. E.; Dovčiak, M.; Pecháček, T.; Emmanoulopoulos, D.; Karas, V.; McHardy, I. M.

    2016-10-01

    Context. Theoretical modelling of time-lags between variations in the Fe Kα emission and the X-ray continuum might shed light on the physics and geometry of the X-ray emitting region in active galaxies (AGN) and X-ray binaries. We here present the results from a systematic analysis of time-lags between variations in two energy bands (5-7 vs. 2-4 keV) for seven X-ray bright and variable AGN. Aims: We estimate time-lags as accurately as possible and fit them with theoretical models in the context of the lamp-post geometry. We also constrain the geometry of the X-ray emitting region in AGN. Methods: We used all available archival XMM-Newton data for the sources in our sample and extracted light curves in the 5-7 and 2-4 keV energy bands. We used these light curves and applied a thoroughly tested (through extensive numerical simulations) recipe to estimate time-lags that have minimal bias, approximately follow a Gaussian distribution, and have known errors. Using traditional χ2 minimisation techniques, we then fitted the observed time-lags with two different models: a phenomenological model where the time-lags have a power-law dependence on frequency, and a physical model, using the reverberation time-lags expected in the lamp-post geometry. The latter were computed assuming a point-like primary X-ray source above a black hole surrounded by a neutral and prograde accretion disc with solar iron abundance. We took all relativistic effects into account for various X-ray source heights, inclination angles, and black hole spin values. Results: Given the available data, time-lags between the two energy bands can only be reliably measured at frequencies between ~5 × 10-5 Hz and ~10-3 Hz. The power-law and reverberation time-lag models can both fit the data well in terms of formal statistical characteristics. When fitting the observed time-lags to the lamp-post reverberation scenario, we can only constrain the height of the X-ray source. The data require, or are consistent

  4. Modelling the cosmological co-evolution of supermassive black holes and galaxies - I. BH scaling relations and the AGN luminosity function

    NASA Astrophysics Data System (ADS)

    Marulli, Federico; Bonoli, Silvia; Branchini, Enzo; Moscardini, Lauro; Springel, Volker

    2008-04-01

    We model the cosmological co-evolution of galaxies and their central supermassive black holes (BHs) within a semi-analytical framework developed on the outputs of the Millennium Simulation. This model, described in detail by Croton et al. and De Lucia and Blaizot, introduces a `radio mode' feedback from active galactic nuclei (AGN) at the centre of X-ray emitting atmospheres in galaxy groups and clusters. Thanks to this mechanism, the model can simultaneously explain: (i) the low observed mass dropout rate in cooling flows; (ii) the exponential cut-off in the bright end of the galaxy luminosity function and (iii) the bulge-dominated morphologies and old stellar ages of the most massive galaxies in clusters. This paper is the first of a series in which we investigate how well this model can also reproduce the physical properties of BHs and AGN. Here we analyse the scaling relations, the fundamental plane and the mass function of BHs, and compare them with the most recent observational data. Moreover, we extend the semi-analytic model to follow the evolution of the BH mass accretion and its conversion into radiation, and compare the derived AGN bolometric luminosity function with the observed one. While we find for the most part a very good agreement between predicted and observed BH properties, the semi-analytic model underestimates the number density of luminous AGN at high redshifts, independently of the adopted Eddington factor and accretion efficiency. However, an agreement with the observations is possible within the framework of our model, provided it is assumed that the cold gas fraction accreted by BHs at high redshifts is larger than at low redshifts.

  5. Problems in unification and supergravity

    SciTech Connect

    Farrar, G.; Henyey, F.

    1984-01-01

    Problems in unification of the various gauge groups, quantum gravity, supersymmetry and supergravity, compact dimensions of space-time, and conditions at the beginning of the universe are discussed. Separate entries were prepared for the data base for the 15 papers presented. (WHK)

  6. AGN Accretion Physics: Insights from K2

    NASA Astrophysics Data System (ADS)

    Vogeley, Michael

    We propose to use Kepler K2 mission observations of 1800 supermassive black holes at the centers of galaxies (Active Galactic Nuclei; AGN) to test models for accretion physics, to study the relationship between variability and other AGN properties such as accretion rate, and to guide methods for detecting and classifying AGN in future time-domain surveys. AGN exhibit optical brightness fluctuations on timescales from below an hour up to many years. These fluctuations are determined by the physics of accretion of matter onto black holes from their galactic environment. By observing variability on timescales down to below an hour, Kepler probes the accretion region on length scales that are too small to be directly imaged using conventional telescopes. These data allow us to test competing models for accretion physics that make different predictions for the statistics of variability. Our previous work provides strong evidence that models of AGN variability that work on long timescale data are not adequate to describe the full range of fluctuation timescales probed by Kepler. We will analyze the light curves of 1800 AGN that have been monitored by Kepler during recent and ongoing K2 campaigns. These objects span a large range of luminosity and AGN type, thus allowing study of the relationship between variability and other physical properties. We will characterize the statistics of AGN variability using state-of-the-art methods of time series analysis that are appropriate for quantifying the stochastic behavior of AGN. This analysis builds on our previous work in which we developed and tested new analysis software that extracts the full information content of these light curves and will enable several key outcomes: (1) Measurement of the relationship between types of AGN and their variability. (2) Tests for dependence of variability on accretion rate. (3) Investigation of changes in variability behavior that point to changes in the mode of accretion. (4) Correlations

  7. Signatures of AGN feedback

    NASA Astrophysics Data System (ADS)

    Wylezalek, D.; Zakamska, N.

    2016-06-01

    Feedback from active galactic nuclei (AGN) is widely considered to be the main driver in regulating the growth of massive galaxies. It operates by either heating or driving the gas that would otherwise be available for star formation out of the galaxy, preventing further increase in stellar mass. Observational proof for this scenario has, however, been hard to come by. We have assembled a large sample of 133 radio-quiet type-2 and red AGN at 0.1AGN-ionized gas, the stellar masses of the host galaxies and their star formation rates. We then investigate the relationships between AGN luminosities, specific star formation rates (sSFR) and outflow strengths W_{90} - the 90% velocity width of the [OIII]λ5007Å line power and a proxy for the AGN-driven outflow speed. Outflow strength W_{90} is independent of sSFR for AGN selected based on their mid-IR luminosity. This is in agreement with previous work that demonstrates that star formation is not sufficient to produce the observed ionized gas outflows which have to be powered by AGN activity. More importantly, we find a negative correlation between W_{90} and sSFR in the AGN hosts with the highest star formation rates, i.e., with the highest gas content. This relationship implies that AGN with strong outflow signatures are hosted in galaxies that are more `quenched' considering their stellar mass than galaxies with weaker outflow signatures. This correlation is only seen in AGN host galaxies with SFR >100 M_{⊙} yr^{-1} where presumably the coupling of the AGN-driven wind to the gas is strongest. This observation is consistent with the AGN having a net suppression, or `negative' impact, through feedback on the galaxies' star formation history.

  8. Infrared interferometry and AGNs: Parsec-scale disks and dusty outflows

    NASA Astrophysics Data System (ADS)

    Burtscher, Leonard; Hönig, Sebastian; Jaffe, Walter; Kishimoto, Makoto; Lopez-Gonzaga, Noel; Meisenheimer, Klaus; Tristam, Konrad R. W.

    2016-08-01

    The "torus" is the central element of the most popular theory unifying various classes of AGNs, but it is usually described as "putative" because it has not been imaged yet. Since it is too small to be resolved with single-dish telescopes, one can only make indirect assumptions about its structure using models. Using infrared interferometry, however, we were able to resolve the circum-nuclear dust distributions for several nearby AGNs and achieved constraints on some further two dozen sources. We discovered circum-nuclear dust on parsec scales in all sources and, in two nearby sources, were able to dissect this dust into two distinct components. The compact component, a very thin disk, appears to be connected to the maser disk and the extended one, which is responsible for most of the mid-IR flux, is oriented perpendicularly to the circum-nuclear gas disks. What may come as a surprise when having in mind the standard unification cartoon actually connects well to observations on larger scales. Optically thin dust in the polar region, perhaps driven by a disk wind, could solve both the scale height problem of the torus and explain the missing anisotropy in the mid-IR - X-ray relation.

  9. Probing Agn Accretion Physics With Kepler

    NASA Astrophysics Data System (ADS)

    Vogeley, Michael

    We propose to use Kepler observations of a sample of ~100 supermassive black holes at the centers of galaxies (Active Galactic Nuclei; AGN) to test models for accretion physics, to study the relationship between variability and other AGN properties, and to guide methods for detecting and classifying AGN in future time-domain surveys. AGN exhibit optical brightness fluctuations on timescales from below an hour up to many years. These fluctuations are determined by the physics of accretion of matter onto black holes from their galactic environment. By observing variability on timescales down to below an hour, Kepler probes the accretion region on length scales that are too small to be directly imaged using conventional telescopes. Data from this unique time- domain telescope now allow us to test competing models for accretion physics that make different predictions for the statistics of variability. Preliminary work provides strong evidence that models of AGN variability that work on long timescale data are not adequate to describe the full range of fluctuation timescales probed by Kepler. We will analyze the light curves of Kepler AGN that span a large range of luminosity and AGN type, thus allowing study of the relationship between variability and other physical properties. Using methods developed and tested by the Kepler team, we will perform custom post-processing of these light curves to remove known systematics. Statistical analyses of the AGN light curves will include estimation of the Structure Function, which quantifies the correlations of brightness fluctuations, and maximum likelihood light curve reconstruction. Competing models for the stochastic behavior of AGN will be tested to evaluate which models best describe variability of AGN over the full range of timescales probed by Kepler. Correlations between the stochastic model parameters and physical parameters will provide new methods for classification of AGN from their variability and aid in

  10. On High-Frequency Topography-Implied Gravity Signals for a Height System Unification Using GOCE-Based Global Geopotential Models

    NASA Astrophysics Data System (ADS)

    Grombein, Thomas; Seitz, Kurt; Heck, Bernhard

    2016-12-01

    National height reference systems have conventionally been linked to the local mean sea level, observed at individual tide gauges. Due to variations in the sea surface topography, the reference levels of these systems are inconsistent, causing height datum offsets of up to ±1-2 m. For the unification of height systems, a satellite-based method is presented that utilizes global geopotential models (GGMs) derived from ESA's satellite mission Gravity field and steady-state Ocean Circulation Explorer (GOCE). In this context, height datum offsets are estimated within a least squares adjustment by comparing the GGM information with measured GNSS/leveling data. While the GNSS/leveling data comprises the full spectral information, GOCE GGMs are restricted to long wavelengths according to the maximum degree of their spherical harmonic representation. To provide accurate height datum offsets, it is indispensable to account for the remaining signal above this maximum degree, known as the omission error of the GGM. Therefore, a combination of the GOCE information with the high-resolution Earth Gravitational Model 2008 (EGM2008) is performed. The main contribution of this paper is to analyze the benefit, when high-frequency topography-implied gravity signals are additionally used to reduce the remaining omission error of EGM2008. In terms of a spectral extension, a new method is proposed that does not rely on an assumed spectral consistency of topographic heights and implied gravity as is the case for the residual terrain modeling (RTM) technique. In the first step of this new approach, gravity forward modeling based on tesseroid mass bodies is performed according to the Rock-Water-Ice (RWI) approach. In a second step, the resulting full spectral RWI-based topographic potential values are reduced by the effect of the topographic gravity field model RWI_TOPO_2015, thus, removing the long to medium wavelengths. By using the latest GOCE GGMs, the impact of topography

  11. On High-Frequency Topography-Implied Gravity Signals for a Height System Unification Using GOCE-Based Global Geopotential Models

    NASA Astrophysics Data System (ADS)

    Grombein, Thomas; Seitz, Kurt; Heck, Bernhard

    2017-03-01

    National height reference systems have conventionally been linked to the local mean sea level, observed at individual tide gauges. Due to variations in the sea surface topography, the reference levels of these systems are inconsistent, causing height datum offsets of up to ±1-2 m. For the unification of height systems, a satellite-based method is presented that utilizes global geopotential models (GGMs) derived from ESA's satellite mission Gravity field and steady-state Ocean Circulation Explorer (GOCE). In this context, height datum offsets are estimated within a least squares adjustment by comparing the GGM information with measured GNSS/leveling data. While the GNSS/leveling data comprises the full spectral information, GOCE GGMs are restricted to long wavelengths according to the maximum degree of their spherical harmonic representation. To provide accurate height datum offsets, it is indispensable to account for the remaining signal above this maximum degree, known as the omission error of the GGM. Therefore, a combination of the GOCE information with the high-resolution Earth Gravitational Model 2008 (EGM2008) is performed. The main contribution of this paper is to analyze the benefit, when high-frequency topography-implied gravity signals are additionally used to reduce the remaining omission error of EGM2008. In terms of a spectral extension, a new method is proposed that does not rely on an assumed spectral consistency of topographic heights and implied gravity as is the case for the residual terrain modeling (RTM) technique. In the first step of this new approach, gravity forward modeling based on tesseroid mass bodies is performed according to the Rock-Water-Ice (RWI) approach. In a second step, the resulting full spectral RWI-based topographic potential values are reduced by the effect of the topographic gravity field model RWI_TOPO_2015, thus, removing the long to medium wavelengths. By using the latest GOCE GGMs, the impact of topography

  12. Fading AGN Candidates: AGN Histories and Outflow Signatures

    NASA Astrophysics Data System (ADS)

    Keel, William C.; Lintott, Chris J.; Maksym, W. Peter; Bennert, Vardha N.; Chojnowski, S. Drew; Moiseev, Alexei; Smirnova, Aleksandrina; Schawinski, Kevin; Sartori, Lia F.; Urry, C. Megan; Pancoast, Anna; Schirmer, Mischa; Scott, Bryan; Showley, Charles; Flatland, Kelsi

    2017-02-01

    We consider the energy budgets and radiative history of eight fading active galactic nuclei (AGNs), identified from an energy shortfall between the requirements to ionize very extended (radius > 10 kpc) ionized clouds and the luminosity of the nucleus as we view it directly. All show evidence of significant fading on timescales of ≈50,000 yr. We explore the use of minimum ionizing luminosity Qion derived from photoionization balance in the brightest pixels in Hα at each projected radius. Tests using presumably constant Palomar–Green QSOs, and one of our targets with detailed photoionization modeling, suggest that we can derive useful histories of individual AGNs, with the caveat that the minimum ionizing luminosity is always an underestimate and subject to uncertainties about fine structure in the ionized material. These consistency tests suggest that the degree of underestimation from the upper envelope of reconstructed Qion values is roughly constant for a given object and therefore does not prevent such derivation. The AGNs in our sample show a range of behaviors, with rapid drops and standstills; the common feature is a rapid drop in the last ≈2 × 104 yr before the direct view of the nucleus. The e-folding timescales for ionizing luminosity are mostly in the thousands of years, with a few episodes as short as 400 yr. In the limit of largely obscured AGNs, we find additional evidence for fading from the shortfall between even the lower limits from recombination balance and the maximum luminosities derived from far-infrared fluxes. We compare these long-term light curves, and the occurrence of these fading objects among all optically identified AGNs, to simulations of AGN accretion; the strongest variations over these timespans are seen in models with strong and local (parsec-scale) feedback. We present Gemini integral-field optical spectroscopy, which shows a very limited role for outflows in these ionized structures. While rings and loops of emission

  13. Minimum X-ray source size for a lamppost corona in light-bending models for AGN

    NASA Astrophysics Data System (ADS)

    Dovciak, M.; Done, C.

    2015-07-01

    The `lamppost' model is often used to describe the X-ray source geometry in AGN, where an infinitesimal point source is located on the black hole spin axis. This is especially invoked for Narrow Line Seyfert 1 galaxies, where an extremely broad iron line seen in episodes of low X-ray flux can be explained by extremely strong relativistic effects as the source approaches the black hole horizon. However, the source must also be large enough to intercept sufficient seed photons from the disc to make the hard X-ray Compton continuum which produces the observed iron line/reflected spectrum. This size scale also sets the minimum height of the corona in order that the source can fit above the event horizon. We calculate this using a fully relativistic ray tracing code, and apply to the most extreme NLS1, 1H0707-495. The inferred source size is too big for it to be at a height of less than one gravitational radius above the horizon.

  14. The origin of UV-optical variability in AGN and test of disc models: XMM-Newton and ground-based observations of NGC 4395

    NASA Astrophysics Data System (ADS)

    McHardy, I. M.; Connolly, S. D.; Peterson, B. M.; Bieryla, A.; Chand, H.; Elvis, M. S.; Emmanoulopoulos, D.; Falco, E.; Gandhi, P.; Kaspi, S.; Latham, D.; Lira, P.; McCully, C.; Netzer, H.; Uemura, M.

    2016-05-01

    The origin of short timescale (weeks/months) variability of AGN, whether due to intrinsic disc variations or reprocessing of X-ray emission by a surrounding accretion disc, has been a puzzle for many years. However recently a number of observational programmes, particularly of NGC 5548 with Swift, have shown that the UV/optical variations lag behind the X-ray variations in a manner strongly supportive of X-ray reprocessing. Somewhat surprisingly, the implied size of the accretion disc is ∼3 times greater than expected from a standard, smooth, Shakura-Sunyaev thin disc model. Although the difference may be explained by a clumpy accretion disc, it is not clear whether the difference will occur in all AGN or whether it may change as, eg, a function of black hole mass, accretion rate, or disc temperature. Measurements of interband lags for most AGN require long timescale monitoring, which is hard to arrange. However for low mass (< 106 M⊙) AGN, the combination of XMM-Newton EPIC (X-rays) with the optical monitor in fast readout mode allows an X-ray/UV-optical lag to be measured within a single long observation. Here we summarise previous related observations and report on XMM-Newton observations of NGC 4395 (mass 100 times lower, accretion rate ∼20 times lower than for NGC 5548). We find that the UVW1 lags the X-rays by ∼ 470 s. Simultaneous observations at 6 different ground based observatories also allowed the g-band lag (∼ 800s) to be measured. These observations are in agreement with X-ray reprocessing but initial analysis suggests that, for NGC 4395, they do not differ markedly from the predictions of the standard thin disc model.

  15. Naval Cooperation After Korean Unification,

    DTIC Science & Technology

    1996-05-01

    Korean Unification _ ’ - < ~ ■::-■;-■’ "’&■ ■ *>’ -■ ■’■ I Analyses for Defense Analyses Center for Korea ... Korea Institute for Defense Analyses (KIDA) held a workshop in Washington, DC, from December 4 to 6, 1995, to examine the prospects for U.S.- Korean ... Korean Navy, coastal missions are certain to continue. Korea will still require defense of its coastlines; regulatory missions to enforce

  16. THE LICK AGN MONITORING PROJECT 2011: DYNAMICAL MODELING OF THE BROAD-LINE REGION IN Mrk 50

    SciTech Connect

    Pancoast, Anna; Brewer, Brendon J.; Treu, Tommaso; Bennert, Vardha N.; Sand, David J.; Barth, Aaron J.; Cooper, Michael C.; Canalizo, Gabriela; Filippenko, Alexei V.; Li, Weidong; Cenko, S. Bradley; Clubb, Kelsey I.; Gates, Elinor L.; Greene, Jenny E.; Malkan, Matthew A.; Stern, Daniel; Assef, Roberto J.; Woo, Jong-Hak; Bae, Hyun-Jin; Buehler, Tabitha; and others

    2012-07-20

    We present dynamical modeling of the broad-line region (BLR) in the Seyfert 1 galaxy Mrk 50 using reverberation mapping data taken as part of the Lick AGN Monitoring Project (LAMP) 2011. We model the reverberation mapping data directly, constraining the geometry and kinematics of the BLR, as well as deriving a black hole mass estimate that does not depend on a normalizing factor or virial coefficient. We find that the geometry of the BLR in Mrk 50 is a nearly face-on thick disk, with a mean radius of 9.6{sup +1.2}{sub -0.9} light days, a width of the BLR of 6.9{sup +1.2}{sub -1.1} light days, and a disk opening angle of 25 {+-} 10 deg above the plane. We also constrain the inclination angle to be 9{sup +7}{sub -5} deg, close to face-on. Finally, the black hole mass of Mrk 50 is inferred to be log{sub 10}(M{sub BH}/M{sub Sun }) = 7.57{sup +0.44}{sub -0.27}. By comparison to the virial black hole mass estimate from traditional reverberation mapping analysis, we find the normalizing constant (virial coefficient) to be log{sub 10} f = 0.78{sup +0.44}{sub -0.27}, consistent with the commonly adopted mean value of 0.74 based on aligning the M{sub BH}-{sigma}* relation for active galactic nuclei and quiescent galaxies. While our dynamical model includes the possibility of a net inflow or outflow in the BLR, we cannot distinguish between these two scenarios.

  17. Vector-like quarks and leptons, SU(5) ⊗ SU(5) grand unification, and proton decay

    NASA Astrophysics Data System (ADS)

    Lee, Chang-Hun; Mohapatra, Rabindra N.

    2017-02-01

    SU(5) ⊗ SU(5) provides a minimal grand unification scheme for fermions and gauge forces if there are vector-like quarks and leptons in nature. We explore the gauge coupling unification in a non-supersymmetric model of this type, and study its implications for proton decay. The properties of vector-like quarks and intermediate scales that emerge from coupling unification play a central role in suppressing proton decay. We find that in this model, the familiar decay mode p → e +π0 may have a partial lifetime within the reach of currently planned experiments.

  18. Identifying Distant AGNs

    NASA Astrophysics Data System (ADS)

    Trouille, Laura; Barger, Amy; Tremonti, Christy

    2014-07-01

    The Baldwin, Phillips, and Terlevich emission-line ratio diagnostic ([OIII]/Hβ versus [NII]/Hα, hereafter BPT diagram) efficiently separates galaxies whose signal is dominated by star formation (BPT-SF) from those dominated by AGN activity (BPT-AGN). Yet the BPT diagram is limited to z<0.5, the redshift at which [NII]λ6584 leaves the optical spectral window. Using the Sloan Digital Sky Survey (SDSS), we construct a new diagnostic, or TBT diagram, that is based on rest-frame g-z color, [NeIII]λ3869, and [OII]λλ3726+3729 and can be used for galaxies out to z<1.4. The TBT diagram identifies 98.7% of the SDSS BPT-AGN as TBT-AGN and 97% of the SDSS BPT-SF as TBT-SF. Furthermore, it identifies 97% of the OPTX Chandra X-ray selected AGNs as TBT-AGN. This is in contrast to the BPT diagram, which misidentifies 20% of X-ray selected AGNs as BPT-SF.

  19. Signatures of AGN feedback

    NASA Astrophysics Data System (ADS)

    Wylezalek, Dominika; Zakamska, Nadia L.; MaNGA-GMOS Team

    2017-01-01

    Feedback from actively accreting SMBHs (Active Galactic Nuclei, AGN) is now widely considered to be the main driver in regulating the growth of massive galaxies. Observational proof for this scenario has, however, been hard to come by. Many attempts at finding a conclusive observational proof that AGN may be able to quench star formation and regulate the host galaxies' growth have shown that this problem is highly complex.I will present results from several projects that focus on understanding the power, reach and impact of feedback processes exerted by AGN. I will describe recent efforts in our group of relating feedback signatures to the specific star formation rate in their host galaxies, where our results are consistent with the AGN having a `negative' impact through feedback on the galaxies' star formation history (Wylezalek+2016a,b). Furthermore, I will show that powerful AGN-driven winds can be easily hidden and not be apparent in the integrated spectrum of the galaxy. This implies that large IFU surveys, such as the SDSS-IV MaNGA survey, might uncover many previously unknown AGN and outflows that are potentially very relevant for understanding the role of AGN in galaxy evolution (Wylezalek+2016c)!

  20. Neutrinos from AGN

    NASA Technical Reports Server (NTRS)

    Kazanas, Demosthenes; White, Nicholas E. (Technical Monitor)

    2000-01-01

    The great penetrating power of neutrinos makes them ideal probe of astrophysical sites and conditions inaccessible to other forms of radiation. These are the centers of stars (collapsing or not) and the centers of Active Galactic Nuclei (AGN). It has been suggested that AGN presented a very promising source of high energy neutrinos, possibly detectable by underwater neutrino detectors. This paper reviews the evolution of ideas concerning the emission of neutrinos from AGN in view of the more recent developments in gamma-ray astronomy and their implications for the neutrino emission from these class of objects.

  1. Steps Toward Unveiling the True Population of AGN: Photometric Selection of Broad-Line AGN

    NASA Astrophysics Data System (ADS)

    Schneider, Evan; Impey, C.

    2012-01-01

    We present an AGN selection technique that enables identification of broad-line AGN using only photometric data. An extension of infrared selection techniques, our method involves fitting a given spectral energy distribution with a model consisting of three physically motivated components: infrared power law emission, optical accretion disk emission, and host galaxy emission. Each component can be varied in intensity, and a reduced chi-square minimization routine is used to determine the optimum parameters for each object. Using this model, both broad- and narrow-line AGN are seen to fall within discrete ranges of parameter space that have plausible bounds, allowing physical trends with luminosity and redshift to be determined. Based on a fiducial sample of AGN from the catalog of Trump et al. (2009), we find the region occupied by broad-line AGN to be distinct from that of quiescent or star-bursting galaxies. Because this technique relies only on photometry, it will allow us to find AGN at fainter magnitudes than are accessible in spectroscopic surveys, and thus probe a population of less luminous and/or higher redshift objects. With the vast availability of photometric data in large surveys, this technique should have broad applicability and result in large samples that will complement X-ray AGN catalogs.

  2. Study of the mid-infrared properties of obscured AGN

    NASA Astrophysics Data System (ADS)

    Severgnini, P.; Caccianiga, A.; della Ceca, R.

    2008-10-01

    The comprehension of the physical properties of obscured AGNs is one of the main goals of the high energy astronomy given their key role in tracing the accretion history of the Universe. Although X-ray and infrared data of AGN with a different level of absorption could provide a direct tool to test the predictions of the AGN models, only few sparse SED of obscured AGN are available so far. We present here the results obtained from Spitzer observations of a statistically complete sample of obscured AGN drawn from the XMM-Newton Hard Bright Sample. This is the largest hard X-ray sample with a complete spectroscopic identification. The Spitzer data, combined with good X-ray and optical spectroscopic data, has allowed us to define powerful diagnostic plots to select heavily obscured AGNs and to build up their spectral energy distributions.

  3. Optically-selected AGN

    NASA Astrophysics Data System (ADS)

    Richard, Gordon

    2016-08-01

    will discuss the selection and properties of optically-selected AGN as contrasted with other multi-wavelength investigations. While optical surveys are able to identify *more* AGNs than other wavelengths, this size comes with a bias towards brighter, unobscured sources. Although optical surveys are not ideal for probing obscured AGNs, I will discuss how they can guide our search for them. The bias towards unobscured sources in the optical is partially mitigated, however, by an increase in information content for the sources that *are* identified---in the form of physics probed by the combination of optical continuum, absorption, and emission. An example is the ability to estimate the mass of AGNs based on the optical/UV emission lines. I will discuss the range of mass (and accretion rate) probed by the optical in addition to serious biases in the black hole mass scaling relations that corrupt these estimates at high redshift.

  4. Grand unification in higher dimensions

    NASA Astrophysics Data System (ADS)

    Hall, Lawrence J.; Nomura, Yasunori

    2003-07-01

    We have recently proposed an alternative picture for the physics at the scale of gauge coupling unification, where the unified symmetry is realized in higher dimensions but is broken locally by a symmetry breaking defect. Gauge coupling unification, the quantum numbers of quarks and leptons and the longevity of the proton arise as phenomena of the symmetrical bulk, while the lightness of the Higgs doublets and the masses of the light quarks and leptons probe the symmetry breaking defect. Moreover, the framework is extremely predictive if the effective higher dimensional theory is valid over a large energy interval up to the scale of strong coupling. Precise agreement with experiments is obtained in the simplest theory— SU(5) in five dimensions with two Higgs multiplets propagating in the bulk. The weak mixing angle is predicted to be sin 2θw=0.2313±0.0004, which fits the data with extraordinary accuracy. The compactification scale and the strong coupling scale are determined to be M c≃5×10 14 GeV and M s≃1×10 17 GeV, respectively. Proton decay with a lifetime of order 10 34 years is expected with a variety of final states such as e+π0, and several aspects of flavor, including large neutrino mixing angles, are understood by the geometrical locations of the matter fields. When combined with a particular supersymmetry breaking mechanism, the theory predicts large lepton flavor violating μ→ e and τ→ μ transitions, with all superpartner masses determined by only two free parameters. The predicted value of the bottom quark mass from Yukawa unification agrees well with the data. This paper is mainly a review of the work presented in hep-ph/0103125, hep-ph/0111068, and hep-ph/0205067 [1-3].

  5. German Unification and Its Ramifications

    DTIC Science & Technology

    1991-01-01

    national iden- tity. Yet the unification of Germany will do more than finally bring to an end the painful realities of German partition; it will also...the Unite Sn-w te4 esn omomic Polly Groi Meet- * irg in B"d we Ju 7-9 190. %9ý Gerniwu OECD £waomk 8wwpy 1990 M (OECD UVW- Seeavo Pao% 1980). i+ i I Ii...also force painful changes within Germany, as it will open or break up a variety of arrangements that have previously protected uncompetitive sectors of

  6. Modeling X-ray Absorbers in AGNs with MHD-Driven Accretion-Disk Winds

    NASA Astrophysics Data System (ADS)

    Fukumura, Keigo; Kazanas, D.; Shrader, C. R.; Tombesi, F.; Contopoulos, J.; Behar, E.

    2013-04-01

    We have proposed a systematic view of the observed X-ray absorbers, namely warm absorbers (WAs) in soft X-ray and highly-ionized ultra-fast outflows (UFOs), in the context of magnetically-driven accretion-disk wind models. While potentially complicated by variability and thermal instability in these energetic outflows, in this simplistic model we have calculated 2D kinematic field as well as density and ionization structure of the wind with density profile of 1/r corresponding to a constant column distribution per decade of ionization parameter. In particular we show semi-analytically that the inner layer of the disk-wind manifests itself as the strongly-ionized fast outflows while the outer layer is identified as the moderately-ionized absorbers. The computed characteristics of these two apparently distinct absorbers are consistent with X-ray data (i.e. a factor of ~100 difference in column and ionization parameters as well as low wind velocity vs. near-relativistic flow). With the predicted contour curves for these wind parameters one can constrain allowed regions for the presence of WAs and UFOs.The model further implies that the UFO's gas pressure is comparable to that of the observed radio jet in 3C111 suggesting that the magnetized disk-wind with density profile of 1/r is a viable agent to help sustain such a self-collimated jet at small radii.

  7. Comparing Simulations of AGN Feedback

    NASA Astrophysics Data System (ADS)

    Richardson, Mark L. A.; Scannapieco, Evan; Devriendt, Julien; Slyz, Adrianne; Thacker, Robert J.; Dubois, Yohan; Wurster, James; Silk, Joseph

    2016-07-01

    We perform adaptive mesh refinement (AMR) and smoothed particle hydrodynamics (SPH) cosmological zoom simulations of a region around a forming galaxy cluster, comparing the ability of the methods to handle successively more complex baryonic physics. In the simplest, non-radiative case, the two methods are in good agreement with each other, but the SPH simulations generate central cores with slightly lower entropies and virial shocks at slightly larger radii, consistent with what has been seen in previous studies. The inclusion of radiative cooling, star formation, and stellar feedback leads to much larger differences between the two methods. Most dramatically, at z=5, rapid cooling in the AMR case moves the accretion shock to well within the virial radius, while this shock remains near the virial radius in the SPH case, due to excess heating, coupled with poorer capturing of the shock width. On the other hand, the addition of feedback from active galactic nuclei (AGNs) to the simulations results in much better agreement between the methods. For our AGN model, both simulations display halo gas entropies of 100 keV cm2, similar decrements in the star formation rate, and a drop in the halo baryon content of roughly 30%. This is consistent with the AGN growth being self-regulated, regardless of the numerical method. However, the simulations with AGN feedback continue to differ in aspects that are not self-regulated, such that in SPH a larger volume of gas is impacted by feedback, and the cluster still has a lower entropy central core.

  8. Flavor mixing in gauge-Higgs unification

    SciTech Connect

    Adachi, Y.; Kurahashi, N.; Lim, C. S.; Maru, N.; Tanabe, K.

    2012-07-27

    Gauge-Higgs unification is the fascinating scenario solving the hierarchy problem without supersymmetry. In this scenario, the Standard Model (SM) Higgs doublet is identified with extra component of the gauge field in higher dimensions and its mass becomes finite and stable under quantum corrections due to the higher dimensional gauge symmetry. On the other hand, Yukawa coupling is provided by the gauge coupling, which seems to mean that the flavor mixing and CP violation do not arise at it stands. In this talk, we discuss that the flavor mixing is originated from simultaneously non-diagonalizable bulk and brane mass matrices. Then, this mechanism is applied to various flavor changing neutral current (FCNC) processes via Kaluza-Klein (KK) gauge boson exchange at tree level and constraints for compactification scale are obtained.

  9. Asymptotically safe grand unification

    NASA Astrophysics Data System (ADS)

    Bajc, Borut; Sannino, Francesco

    2016-12-01

    Phenomenologically appealing supersymmetric grand unified theories have large gauge representations and thus are not asymptotically free. Their ultraviolet validity is limited by the appearance of a Landau pole well before the Planck scale. One could hope that these theories save themselves, before the inclusion of gravity, by generating an interacting ultraviolet fixed point, similar to the one recently discovered in non-supersymmetric gauge-Yukawa theories. Employing a-maximization, a-theorem, unitarity bounds, as well as positivity of other central charges we nonperturbatively rule out this possibility for a broad class of prime candidates of phenomenologically relevant supersymmetric grand unified theories. We also uncover candidates passing these tests, which have either exotic matter or contain one field decoupled from the superpotential. The latter class of theories contains a model with the minimal matter content required by phenomenology.

  10. JetCurry: Modeling 3D geometry of AGN jets from 2D images

    NASA Astrophysics Data System (ADS)

    Kosak, Katie; Li, KunYang; Avachat, Sayali S.; Perlman, Eric S.

    2017-02-01

    Written in Python, JetCurry models the 3D geometry of jets from 2-D images. JetCurry requires NumPy and SciPy and incorporates emcee (ascl:1303.002) and AstroPy (ascl:1304.002), and optionally uses VPython. From a defined initial part of the jet that serves as a reference point, JetCurry finds the position of highest flux within a bin of data in the image matrix and fits along the x axis for the general location of the bends in the jet. A spline fitting is used to smooth out the resulted jet stream.

  11. Obscured AGN Accretion Across Cosmic Time

    NASA Astrophysics Data System (ADS)

    Coil, Alison

    for the unified model of AGN. Our X-ray absorption study will accurately determine the distribution of AGN absorption column densities. We will measure the dependence of this absorption distribution on both luminosity and redshift to z~3, resolving outstanding discrepancies in the literature. We propose to develop and implement a new Bayesian X-ray spectral fitting technique to obtain unbiased measurements of absorption column densities and their associated uncertainties. By compiling large samples of X-ray sources over a wide range of redshifts and depths and fully propagating the errors in individual measurements of column densities and X-ray luminosities, we will robustly measure the joint evolution of AGN accretion activity and absorption properties. In all of these projects we will adopt advanced methodologies to quantify and correct for selection effects, incompleteness, and biases, which severely hamper such studies if not fully accounted for. Our proposed work will allow us to place strong constraints on the prominence of obscured AGN activity and reveal the true evolution of AGN accretion over the history of the Universe. To ensure the legacy and impact of our findings, we commit to publicly release major, high-level data products. This will build on the substantial archive of public data available from the AEGIS and DEEP survey teams and the forthcoming release from PRIMUS. We will release catalogs providing accurate measurements of X-ray luminosities, column densities, and photometric redshifts with robust error estimates for our large samples of X-ray sources, covering the most prominent extragalactic survey fields.

  12. Internal supersymmetry and unification

    PubMed Central

    Ne'eman, Yuval; Sternberg, Shlomo

    1980-01-01

    We construct a family of finite-dimensional representations of the superalgebra sl(n/m) that depend on an integer parameter for m > 1 and on a complex parameter, b, for m = 1. We describe some models of elementary particles for sl(2/1), sl(3/1), and sl(5/1). This involves the choice of the parameter b and the choice of the operators I3 (the third component of the weak left-handed isospin) and U (the weak hypercharge). These must commute, and are related to the electric charge by the usual formula Q = I3 + ½U. In particular, taking I3 to be in its standard form in su(2) ⊂ sl(5) ⊂ sl(5/1) and requiring that U commute with color su(3) ⊂ sl(5) ⊂ sl(5/1) leaves three free parameters, two for the choice of U and one for the choice of b. We show that there are just two possible choices of these parameters yielding exactly all 32 quark and lepton charges: the Georgi-Glashow U ∈ su(5), corresponding to U(1,-⅔) and arbitrary b and U(0,⅓) ∉ su(5), with b = 2. We provide a general construction of representations of sl(n/1) consisting exactly of sequences of generations of quarks and leptons. PMID:16592837

  13. Unification of quantum information theory

    NASA Astrophysics Data System (ADS)

    Abeyesinghe, Anura

    We present the unification of many previously disparate results in noisy quantum Shannon theory and the unification of all of noiseless quantum Shannon theory. More specifically we deal here with bipartite, unidirectional, and memoryless quantum Shannon theory. We find all the optimal protocols and quantify the relationship between the resources used, both for the one-shot and for the ensemble case, for what is arguably the most fundamental task in quantum information theory: sharing entangled states between a sender and a receiver. We find that all of these protocols are derived from our one-shot superdense coding protocol and relate nicely to each other. We then move on to noisy quantum information theory and give a simple, direct proof of the "mother" protocol, or rather her generalization to the Fully Quantum Slepian-Wolf protocol (FQSW). FQSW simultaneously accomplishes two goals: quantum communication-assisted entanglement distillation, and state transfer from the sender to the receiver. As a result, in addition to her other "children," the mother protocol generates the state merging primitive of Horodecki, Oppenheim, and Winter as well as a new class of distributed compression protocols for correlated quantum sources, which are optimal for sources described by separable density operators. Moreover, the mother protocol described here is easily transformed into the so-called "father" protocol, demonstrating that the division of single-sender/single-receiver protocols into two families was unnecessary: all protocols in the family are children of the mother.

  14. Towards modelling X-ray reverberation in AGN: piecing together the extended corona

    NASA Astrophysics Data System (ADS)

    Wilkins, D. R.; Cackett, E. M.; Fabian, A. C.; Reynolds, C. S.

    2016-05-01

    Models of X-ray reverberation from extended coronae are developed from general relativistic ray tracing simulations. Reverberation lags between correlated variability in the directly observed continuum emission and that reflected from the accretion disc arise due to the additional light travel time between the corona and reflecting disc. X-ray reverberation is detected from an increasing sample of Seyfert galaxies and a number of common properties are observed, including a transition from the characteristic reverberation signature at high frequencies to a hard lag within the continuum component at low frequencies, as well as a pronounced dip in the reverberation lag at 3 keV. These features are not trivially explained by the reverberation of X-rays originating from simple point sources. We therefore model reverberation from coronae extended both over the surface of the disc and vertically. Causal propagation through its extent for both the simple case of constant velocity propagation and propagation linked to the viscous time-scale in the underlying accretion disc is included as well as stochastic variability arising due to turbulence locally on the disc. We find that the observed features of X-ray reverberation in Seyfert galaxies can be explained if the long time-scale variability is dominated by the viscous propagation of fluctuations through the corona. The corona extends radially at low height over the surface of the disc but with a bright central region in which fluctuations propagate up the black hole rotation axis driven by more rapid variability arising from the innermost regions of the accretion flow.

  15. Observational evidence for thin AGN disks

    NASA Technical Reports Server (NTRS)

    Netzer, Hagai

    1992-01-01

    AGN spectrum and spectral features, polarization, inclination, and X-ray line and continuum reflection features are discussed in a critical way in order to determine the ones that are the least model-dependent. The sign and strength of absorption and emission edges are found to be model-dependent, and relativistic broadening and shifting makes them hard to detect. The presence or absence of the predicted Lyman edge polarization feature may be used as a decisive test for thin, bare AGN disks. Other good model-independent tests are several inclination-related line and continuum correlations in big AGN samples. It is shown that electron temperature near the surface of the disk can greatly exceed the disk equilibrium temperature, which causes deviations from LTE. This effect must be incorporated into realistic disk models.

  16. Gravi-weak unification and multiple-point principle

    SciTech Connect

    Das, S. R.; Laperashvili, L. V.; Nielsen, H. B.; Tureanu, A.; Froggatt, C. D.

    2015-05-15

    The problem of self-consistency of the unification of gravity and weak SU(2) interaction in a model that is invariant under the Spin(4, 4) group is studied. For this purpose, consequences of the multicritical-point principle, which admits the existence of two degenerate vacua in the Standard Model, are considered. Also, the existence of a visible and an invisible sector in our Universe is assumed.

  17. Insensitive unification of gauge couplings with three vector-like families

    SciTech Connect

    Dermisek, Radovan

    2013-05-23

    The standard model extended by three vector-like families with masses of order 1 TeV - 100 TeV allows for unification of gauge couplings. The values of gauge couplings at the electroweak scale are highly insensitive to fundamental parameters. The grand unification scale is large enough to avoid the problem with fast proton decay. The electroweak minimum of the Higgs potential is stable.

  18. Parallel unification scheduling in Prolog. Technical report

    SciTech Connect

    Citrin

    1986-09-18

    Unification, the fundamental operation in the Prolog logic programming language can take up to 50% of the execution time of a typical Prolog system. One approach to speeding up the unification operation is to perform it on parallel hardware. Although it has been shown that, in general, there is no parallel algorithm for unification that is better than the best sequential algorithm, there is a substantial subset of unification which may be done in parallel. Identifying these subsets involves gathering data using an extension of Chang's static data-dependency analysis (SDDA), then using that data to schedule the components of a unification for parallel unification. Improvements to the information gathered by SDDA may be achieved through procedures splitting, a source-level transformation of the program. This thesis describes and evaluates the above-mentioned techniques and their implementation. Results are compared to other techniques for speeding up unification. Ways in which these techniques may be applied to the Berkeley PLM machine are also described.

  19. Regular expression order-sorted unification and matching

    PubMed Central

    Kutsia, Temur; Marin, Mircea

    2015-01-01

    We extend order-sorted unification by permitting regular expression sorts for variables and in the domains of function symbols. The obtained signature corresponds to a finite bottom-up unranked tree automaton. We prove that regular expression order-sorted (REOS) unification is of type infinitary and decidable. The unification problem presented by us generalizes some known problems, such as, e.g., order-sorted unification for ranked terms, sequence unification, and word unification with regular constraints. Decidability of REOS unification implies that sequence unification with regular hedge language constraints is decidable, generalizing the decidability result of word unification with regular constraints to terms. A sort weakening algorithm helps to construct a minimal complete set of REOS unifiers from the solutions of sequence unification problems. Moreover, we design a complete algorithm for REOS matching, and show that this problem is NP-complete and the corresponding counting problem is #P-complete. PMID:26523088

  20. Intermittent Activity in AGN

    NASA Astrophysics Data System (ADS)

    Janiuk, A.; Czerny, B.; Siemiginowska, A.

    2004-10-01

    There is a growing evidence that the AGN activity could be intermittent. It remains an open question if this behavior is caused by changes in the fuel sup- ply to the supermassive black hole from the large distances, or rather by a processes intrinsic to the active nucleus. We consider the possibility that ac- cretion onto a supermassive black hole is controlled by an accretion disk which is subject to the hydro- gen ionization instability. This drives the observed on-off activity cycle, since periodically the accretion flow becomes inefficient and the disk goes to quies- cence. We consider effects of the MHD turbulence on the viscosity during the evolution of a standard α - disk. We perform a self-consistency check of the α de- scription of the angular momentum transfer. Hav- ing shown that the viscosity parameter is constant throughout the whole instability cycle, as implied by the strength of the MHD turbulence, we calcu- late the time evolution of the disk under the influ- ence of the ionization instability. We demonstrate that if the accretion onto a supermassive black hole proceeds through an outer standard accretion disk and inner, radiatively inefficient and advection dom- inated flow, the modelled amplitudes of disk lumi- nosity variations are sufficiently high to account for the observations. Key words: accretion disks; galaxies: active.

  1. Evidence for Ultra-Fast Outflows in Radio-Quiet AGNs. 2; Detailed Photoionization Modeling of Fe K-Shell Absorption Lines

    NASA Technical Reports Server (NTRS)

    Tombesi, Francesco; Clapp, M.; Reeves, J. N.; Palumbo, G. G. C.; Braito, V.; Dadina, M.

    2011-01-01

    X-ray absorption line spectroscopy has recently shown evidence for previously unknown Ultra-fast Outflows (UFOs) in radio-quiet AGNs. In the previous paper of this series we defined UFOs as those absorbers with an outflow velocity higher than 10,000km/s and assessed the statistical significance of the associated blue shifted FeK absorption lines in a large sample of 42 local radio-quiet AGNs observed with XMM-Newton. In the present paper we report a detailed curve of growth analysis and directly model the FeK absorbers with the Xstar photo-ionization code. We confirm that the frequency of sources in the radio-quiet sample showing UFOs is >35%. The outflow velocity distribution spans from \\sim10,000km/s (\\sim0.03c) up to \\siml00,000kmis (\\sim0.3c), with a peak and mean value of\\sim42,000km/s (\\sim0.14c). The ionization parameter is very high and in the range log\\xi 3-6 erg s/cm, with a mean value of log\\xi 4.2 erg s/cm. The associated column densities are also large, in the range N_H\\siml0(exp 22)-10(exp 24)/sq cm, with a mean value of N_H\\siml0(exp23)/sq cm. We discuss and estimate how selection effects, such as those related to the limited instrumental sensitivity at energies above 7keV, may hamper the detection of even higher velocities and higher ionization absorbers. We argue that, overall, these results point to the presence of extremely ionized and possibly almost Compton thick outflowing material in the innermost regions of AGNs. This also suggests that UFOs may potentially play a significant role in the expected cosmological feedback from AGNs and their study can provide important clues on the connection between accretion disks, winds and jets.

  2. Grand unification of neutron stars.

    PubMed

    Kaspi, Victoria M

    2010-04-20

    The last decade has shown us that the observational properties of neutron stars are remarkably diverse. From magnetars to rotating radio transients, from radio pulsars to isolated neutron stars, from central compact objects to millisecond pulsars, observational manifestations of neutron stars are surprisingly varied, with most properties totally unpredicted. The challenge is to establish an overarching physical theory of neutron stars and their birth properties that can explain this great diversity. Here I survey the disparate neutron stars classes, describe their properties, and highlight results made possible by the Chandra X-Ray Observatory, in celebration of its 10th anniversary. Finally, I describe the current status of efforts at physical "grand unification" of this wealth of observational phenomena, and comment on possibilities for Chandra's next decade in this field.

  3. Gauge coupling unification and nonequilibrium thermal dark matter.

    PubMed

    Mambrini, Yann; Olive, Keith A; Quevillon, Jérémie; Zaldívar, Bryan

    2013-06-14

    We study a new mechanism for the production of dark matter in the Universe which does not rely on thermal equilibrium. Dark matter is populated from the thermal bath subsequent to inflationary reheating via a massive mediator whose mass is above the reheating scale T(RH). To this end, we consider models with an extra U(1) gauge symmetry broken at some intermediate scale (M(int) ≃ 10(10)-10(12) GeV). We show that not only does the model allow for gauge coupling unification (at a higher scale associated with grand unification) but it can provide a dark matter candidate which is a standard model singlet but charged under the extra U(1). The intermediate scale gauge boson(s) which are predicted in several E6/SO(10) constructions can be a natural mediator between dark matter and the thermal bath. We show that the dark matter abundance, while never having achieved thermal equilibrium, is fixed shortly after the reheating epoch by the relation T(RH)(3)/M(int)(4). As a consequence, we show that the unification of gauge couplings which determines M(int) also fixes the reheating temperature, which can be as high as T(RH) ≃ 10(11) GeV.

  4. The Economic Implications of Korean Unification

    DTIC Science & Technology

    2002-06-01

    the two sides agreed to push for a joint Imjin River flood 80 Byung Chul Koh, ed. Korea: Dynamics...background_notes. 82 Byung Chul Koh, Korea: Dynamics of Diplomacy and Unification, 86. 27 control project at an early date. And they were able to...publications/factbook. 85 Byung Chul Koh, Korea: Dynamics of Diplomacy and Unification, 34. 28 idea as the Korean economy slowly recovers from the Asian

  5. The Role of China in Korean Unification

    DTIC Science & Technology

    2003-06-01

    Westview Press, 1988. p. 21. 63 Byung Chul Koh. The Foreign Policy Systems of North and South Korea. Berkeley and Los Angeles, California...Unification: A Framework for Policy Choices in Korea.” Korea: Dynamics and Diplomacy and Unification. Byung Chul Koh. (Ed.) CA: CMC/KECK, 2001. p. 171. 243...Security Policy in the Era of Reform, 1978-2000. David M. Lampton (Ed.). Stanford, California: Stanford University Press, 2001. Koh, Byung Chul . The

  6. Measuring Feedback in Nearby AGN

    NASA Astrophysics Data System (ADS)

    Crenshaw, D. M.; Fischer, T. C.; Kraemer, S. B.; Schmitt, H. R.; Turner, T. J.

    2012-08-01

    We investigate the impact of feedback from outflowing UV and X-ray absorbers in nearby (z < 0.04) AGN. From studies of the kinematics, physical conditions, and variability of the absorbers in the literature, we calculate the possible ranges in total mass outflow rate (Ṁout) and kinetic luminosity (LK) for each AGN, summed over all of the absorbers. These calculations make use of values (or limits) for the radial locations of the absorbers determined from variability, excited-state absorption, or other considerations. From a sample of 10 Seyfert 1 galaxies with detailed photoionization models for their absorbers, we find that 7 have sufficient constraints on the absorber locations to determine Ṁout and LK. The 6 Seyfert 1s with moderate bolometric luminosities (Lbol = 1043 - 1045 ergs s-1) all have mass outflow rates that are 10 - 1000 times the mass accretion rates needed to generate their observed luminosities, indicating that most of the mass outflow originates from outside the inner accretion disk. Three of these (NGC 4051, NGC 3516, and NGC 3783) have LK in the range 0.5 - 5% Lbol, which is the range typically required by feedback models for efficient self-regulation of black-hole and galactic bulge growth. The other three (NGC 5548, NGC 4151, and NGC 7469) have LK > 0.1%Lbol, although these values may increase if radial locations can be determined for more of the absorbers. We conclude that the outflowing UV and X-ray absorbers in moderate-luminosity AGN have the potential to deliver significant feedback to their environments.

  7. AGN-2979, an inhibitor of tryptophan hydroxylase activation, does not affect serotonin synthesis in Flinders Sensitive Line rats, a rat model of depression, but produces a significant effect in Flinders Resistant Line rats

    PubMed Central

    Kanemaru, Kazuya; Nishi, Kyoko; Diksic, Mirko

    2009-01-01

    The neurotransmitter, serotonin, is involved in several brain functions, including both normal, physiological functions, and pathophysiological functions. Alterations in any of the normal parameters of serotonergic neurotransmission can produce several different psychiatric disorders, including major depression. In many instances, brain neurochemical variables are not able to be studied properly in humans, thus making the use of good animal models extremely valuable. One of these animal models is the Flinders Sensitive Line (FSL) of rats, which has face, predictive and constructive validities in relation to human depression. The objective of this study was to quantify the effect of the tryptophan hydroxylase (TPH) activation inhibitor, AGN-2979, on the FSL rats (rats with depression-like behaviour), and compare it to the effect on the Flinders Resistant Line (FRL) of rats used as the control rats. The effect was evaluated by measuring changes in regional serotonin synthesis in the vehicle treated rats (FSL-VEH and FRL-VEH) relative to those measured in the AGN-2979 treated rats (FSL-AGN and FRL-AGN). Regional serotonin synthesis was measured autoradiographically in more than thirty brain regions. The measurements were performed using α-[14C]methyl-L-tryptophan as the tracer. The results indicate that AGN-2979 did not produce a significant reduction of TPH activity in the AGN-2979 group relative to the vehicle group (a reduction would have been observed if there had been an activation of TPH by the experimental set up) in the FSL rats. On the other hand, there was a highly significant reduction of synthesis in the FRL rats treated by AGN-2979, relative to the vehicle group. Together, the results demonstrate that in the FSL rats, AGN-2979 does not affect serotonin synthesis. This suggests that there was no activation of TPH in the FSL rats during the experimental procedure, but such activation did occur in the FRL rats. Because of this finding, it could be

  8. A UV to mid-IR study of AGN selection

    SciTech Connect

    Chung, Sun Mi; Kochanek, Christopher S.; Assef, Roberto; Brown, Michael J. I.; Stern, Daniel; Jannuzi, Buell T.; Gonzalez, Anthony H.; Hickox, Ryan C.; Moustakas, John

    2014-07-20

    We classify the spectral energy distributions (SEDs) of 431,038 sources in the 9 deg{sup 2} Boötes field of the NOAO Deep Wide-Field Survey (NDWFS). There are up to 17 bands of data available per source, including ultraviolet (GALEX), optical (NDWFS), near-IR (NEWFIRM), and mid-infrared (IRAC and MIPS) data, as well as spectroscopic redshifts for ∼20,000 objects, primarily from the AGN and Galaxy Evolution Survey. We fit galaxy, active galactic nucleus (AGN), stellar, and brown dwarf templates to the observed SEDs, which yield spectral classes for the Galactic sources and photometric redshifts and galaxy/AGN luminosities for the extragalactic sources. The photometric redshift precision of the galaxy and AGN samples are σ/(1 + z) = 0.040 and σ/(1 + z) = 0.169, respectively, with the worst 5% outliers excluded. On the basis of the χ{sub ν}{sup 2} of the SED fit for each SED model, we are able to distinguish between Galactic and extragalactic sources for sources brighter than I = 23.5 mag. We compare the SED fits for a galaxy-only model and a galaxy-AGN model. Using known X-ray and spectroscopic AGN samples, we confirm that SED fitting can be successfully used as a method to identify large populations of AGNs, including spatially resolved AGNs with significant contributions from the host galaxy and objects with the emission line ratios of 'composite' spectra. We also use our results to compare with the X-ray, mid-IR, optical color, and emission line ratio selection techniques. For an F-ratio threshold of F > 10, we find 16,266 AGN candidates brighter than I = 23.5 mag and a surface density of ∼1900 AGN deg{sup –2}.

  9. AGN Variability: Probing Black Hole Accretion

    NASA Astrophysics Data System (ADS)

    Moreno, Jackeline; O'Brien, Jack; Vogeley, Michael S.; Richards, Gordon T.; Kasliwal, Vishal P.

    2017-01-01

    We combine the long temporal baseline of Sloan Digital Sky Survey (SDSS) for quasars in Stripe 82 with the high precision photometry of the Kepler/K2 Satellite to study the physics of optical variability in the accretion disk and supermassive black hole engine. We model the lightcurves directly as Continuous-time Auto Regressive Moving Average processes (C-ARMA) with the Kali analysis package (Kasliwal et al. 2016). These models are extremely robust to irregular sampling and can capture aperiodic variability structure on various timescales. We also estimate the power spectral density and structure function of both the model family and the data. A Green's function kernel may also be estimated for the resulting C-ARMA parameter fit, which may be interpreted as the response to driving impulses such as hotspots in the accretion disk. We also examine available spectra for our AGN sample to relate observed and modelled behavior to spectral properties. The objective of this work is twofold: to explore the proper physical interpretation of different families of C-ARMA models applied to AGN optical flux variability and to relate empirical characteristic timescales of our AGN sample to physical theory or to properties estimated from spectra or simulations like the disk viscosity and temperature. We find that AGN with strong variability features on timescales resolved by K2 are well modelled by a low order C-ARMA family while K2 lightcurves with weak amplitude variability are dominated by outliers and measurement errors which force higher order model fits. This work explores a novel approach to combining SDSS and K2 data sets and presents recovered characteristic timescales of AGN variability.

  10. Graviweak Unification, Invisible Universe and Dark Energy

    NASA Astrophysics Data System (ADS)

    Das, C. R.; Laperashvili, L. V.; Tureanu, A.

    2013-07-01

    We consider a graviweak unification model with the assumption of the existence of a hidden (invisible) sector of our Universe, parallel to the visible world. This Hidden World (HW) is assumed to be a Mirror World (MW) with broken mirror parity. We start with a diffeomorphism invariant theory of a gauge field valued in a Lie algebra g, which is broken spontaneously to the direct sum of the space-time Lorentz algebra and the Yang-Mills algebra: ˜ {g} = {{su}}(2) (grav)L ⊕ {{su}}(2)L — in the ordinary world, and ˜ {g}' = {{su}}(2){' (grav)}R ⊕ {{su}}(2)'R — in the hidden world. Using an extension of the Plebanski action for general relativity, we recover the actions for gravity, SU(2) Yang-Mills and Higgs fields in both (visible and invisible) sectors of the Universe, and also the total action. After symmetry breaking, all physical constants, including the Newton's constants, cosmological constants, Yang-Mills couplings, and other parameters, are determined by a single parameter g present in the initial action, and by the Higgs VEVs. The dark energy problem of this model predicts a too large supersymmetric breaking scale (MSUSY 1010GeV), which is not within the reach of the LHC experiments.

  11. Does the obscured AGN fraction really depend on luminosity?

    NASA Astrophysics Data System (ADS)

    Sazonov, S.; Churazov, E.; Krivonos, R.

    2015-12-01

    We use a sample of 151 local non-blazar active galactic nuclei (AGN) selected from the INTEGRAL all-sky hard X-ray survey to investigate if the observed declining trend of the fraction of obscured (i.e. showing X-ray absorption) AGN with increasing luminosity is mostly an intrinsic or selection effect. Using a torus-obscuration model, we demonstrate that in addition to negative bias, due to absorption in the torus, in finding obscured AGN in hard X-ray flux-limited surveys, there is also positive bias in finding unobscured AGN, due to Compton reflection in the torus. These biases can be even stronger taking into account plausible intrinsic collimation of hard X-ray emission along the axis of the obscuring torus. Given the AGN luminosity function, which steepens at high luminosities, these observational biases lead to a decreasing observed fraction of obscured AGN with increasing luminosity even if this fraction has no intrinsic luminosity dependence. We find that if the central hard X-ray source in AGN is isotropic, the intrinsic (i.e. corrected for biases) obscured AGN fraction still shows a declining trend with luminosity, although the intrinsic obscured fraction is significantly larger than the observed one: the actual fraction is larger than ˜85 per cent at L ≲ 1042.5 erg s-1 (17-60 keV), and decreases to ≲60 per cent at L ≳ 1044 erg s-1. In terms of the half-opening angle θ of an obscuring torus, this implies that θ ≲ 30° in lower luminosity AGN, and θ ≳ 45° in higher luminosity ones. If, however, the emission from the central supermassive black hole is collimated as dL/dΩ ∝ cos α, the intrinsic dependence of the obscured AGN fraction is consistent with a luminosity-independent torus half-opening angle θ ˜ 30°.

  12. NuSTAR Observations of Bright AGNs

    NASA Astrophysics Data System (ADS)

    Elvis, Martin; Ballantyne, D. R.; Blandford, R. D.; Boggs, S.; Boydstun, K.; Brenneman, L.; Cappi, M.; Christensen, F.; Craig, W.; Fabian, A.; Fuerst, F.; Guainazzi, M.; Hailey, C. J.; Harrison, F.; Madejski, G. M.; Marinucci, A.; Matt, G.; Nandra, K.; Reynolds, C. S.; Stern, D.; Walton, D.; Zhang, W.; NuSTAR Team

    2013-01-01

    The dramatically improved signal-to-noise provided by NuSTAR up to ~80 keV allows a qualitative change in our understanding of the X-ray emission of Active Galactic Nuclei (AGNs). Despite intensive investigation for over 30 years, during which the 0.1-10 keV spectra and variability of AGNs have been mapped out in detail, we do not know the origin of the X-ray source in AGNs. The "standard model" of supermassive black hole, accretion disk and relativistic jet does not predict an X-ray source in a straightforward way. It is usually assumed that the X-rays were UV photons from the accretion disk that have been Compton up-scattered in a "hot corona", but the temperature, optical depth and geometry of this corona are unknown - if it exists. NuSTAR enables the measurement of the high energy cut-off of the X-ray spectrum, and so the corona temperature, to be measured precisely for the first time, and tests the relativistic Fe-K line and Compton reflection models. If this model is correct then, with Suzaku and XMM-Newton, NuSTAR can measure black hole spins to high accuracy. We outline the NuSTAR GTO program on bright, unobscured, AGNs including simultaneous observations with Suzaku and XMM-Newton, and show early data.

  13. THE LACK OF TORUS EMISSION FROM BL LACERTAE OBJECTS: AN INFRARED VIEW OF UNIFICATION WITH WISE

    SciTech Connect

    Plotkin, Richard M.; Markoff, Sera; Anderson, Scott F.; Brandt, W. N.; Wu Jianfeng; Shemmer, Ohad

    2012-02-15

    We use data from the Wide-Field Infrared Survey Explorer (WISE) to perform a statistical study on the mid-infrared (IR) properties of a large number ({approx}10{sup 2}) of BL Lac objects-low-luminosity active galactic nuclei (AGNs) with a jet beamed toward the Earth. As expected, many BL Lac objects are so highly beamed that their jet synchrotron emission dominates their IR spectral energy distributions. In other BL Lac objects, however, the jet is not strong enough to completely dilute the rest of the AGN emission. We do not see observational signatures of the dusty torus from these weakly beamed BL Lac objects. The lack of observable torus emission is consistent with suggestions that BL Lac objects are fed by radiatively inefficient accretion disks. Implications for the 'nature versus nurture' debate for FR I and FR II radio galaxies are briefly discussed. Our study supports the notion that, beyond orientation, accretion rate plays an important role in AGN unification.

  14. International Scientific Terminology and Neologisms in the Course of Unification.

    ERIC Educational Resources Information Center

    Stoberski, Zygmunt

    1978-01-01

    Provides a list of international medical and pharmaceutical terminology in three stages of development: (1) established international terms; (2) neologisms in the course of unification; and (3) recent neologisms in the course of unification. (AM)

  15. Starburst or AGN dominance in submm-luminous candidate AGN

    NASA Astrophysics Data System (ADS)

    Coppin, Kristen; Alexander, Dave; Aretxaga, Itziar; Blain, Andrew; Chapman, Scott; Clements, Dave; Dunlop, James; Dunne, Loretta; Dye, Simon; Farrah, Duncan; Hughes, David; Ivison, Rob; Kim, Sungeun; Menendez-Delmestre, Karin; Oliver, Sebastian; Page, Mat; Pope, Alexandra; Rowan-Robinson, Michael; Scott, Douglas; Smail, Ian; Swinbank, Mark; Vaccari, Mattia; van Kampen, Eelco

    2008-03-01

    It is widely believed that starbursts/ULIRGs and AGN activity are triggered by galaxy interactions and merging; and sub-mm selected galaxies (SMGs) seem to be simply high redshift ULIRGs, observed near the peak of activity. In this evolutionary picture every SMG would host an AGN, which would eventually grow a black hole strong enough to blow off all of the gas and dust leaving an optically luminous QSO. In order to probe this evolutionary sequence, a crucial sub-sample to focus on would be the 'missing link' sources, which demonstrate both strong starburst and AGN signatures and to determine if the starburst is the main power source even in SMGs when we have evidence that an AGN is present. The best way to determine if a dominant AGN is present is to look in the mid-IR for their signatures, since often even deep X-ray observations miss identifying the presence of AGN in heavily dust-obscured SMGs. We have selected a sample of SMGs which are good candidates for harboring powerful AGN on the basis of their IRAC colours (S8um/S4.5um>2). Once we confirm these SMGs are AGN-dominated, we can then perform an audit of the energy balance between star-formation and AGN within this special sub-population of SMGs where the BH has grown appreciably to begin heating the dust emission. The proposed observations with IRS will probe the physics of how SMGs evolve from a cold-dust starburst-dominated ULIRG to an AGN/QSO by measuring the level of the mid-IR continuum, PAH luminosity, and Si absorption in these intermediate `transitory' AGN/SMGs.

  16. The Lick AGN Monitoring Project 2016: Extending Reverberation Mapping to Higher Luminosity AGNs

    NASA Astrophysics Data System (ADS)

    U, Vivian; LAMP2016 Collaboration

    2017-01-01

    The technique of reverberation mapping has been used to estimate virial black hole masses and, more fundamentally, to probe the broad line region structure in Seyfert I galaxies. Efforts from the previous Lick AGN Monitoring Project (LAMP) campaigns and other studies to date have culminated in a large sample of reverberation mapped AGNs and measurements of their black hole masses, which in turn enabled major improvement to various AGN scaling relations. However, the high-luminosity end of such relations remains poorly constrained; this is because of observational challenges presented by the weaker continuum flux variations and longer time dilation in these sources. To this end, we have initiated a new LAMP2016 campaign to target AGNs with luminosities of 10^44 erg/s, with predicted H-beta lags of ~20 - 60 days or black hole masses of 10^7 - 10^8.5 Msun. Designed to monitor ~20 AGNs biweekly from Spring 2016 through Winter 2017 with the Kast spectrograph on the 3-m Shane Telescope at Lick Observatory, we aim to probe luminosity-dependent trends in broad line region structure and dynamics, improve calibrations for single-epoch estimates of high-redshift quasar black hole masses, and test photoionization models for the radially-stratified structure of the broad line region. In this talk, I will present the overview and scope of LAMP2016 and show preliminary results from our ongoing campaign.

  17. Disentangling AGN and Star Formation in Soft X-Rays

    NASA Technical Reports Server (NTRS)

    LaMassa, Stephanie M.; Heckman, T. M.; Ptak, A.

    2012-01-01

    We have explored the interplay of star formation and active galactic nucleus (AGN) activity in soft X-rays (0.5-2 keV) in two samples of Seyfert 2 galaxies (Sy2s). Using a combination of low-resolution CCD spectra from Chandra and XMM-Newton, we modeled the soft emission of 34 Sy2s using power-law and thermal models. For the 11 sources with high signal-to-noise Chandra imaging of the diffuse host galaxy emission, we estimate the luminosity due to star formation by removing the AGN, fitting the residual emission. The AGN and star formation contributions to the soft X-ray luminosity (i.e., L(sub x,AGN) and L(sub x,SF)) for the remaining 24 Sy2s were estimated from the power-law and thermal luminosities derived from spectral fitting. These luminosities were scaled based on a template derived from XSINGS analysis of normal star-forming galaxies. To account for errors in the luminosities derived from spectral fitting and the spread in the scaling factor, we estimated L(sub x,AGN) and L(sub x,SF))from Monte Carlo simulations. These simulated luminosities agree with L(sub x,AGN) and L(sub x,SF) derived from Chandra imaging analysis within a 3sigma confidence level. Using the infrared [Ne ii]12.8 micron and [O iv]26 micron lines as a proxy of star formation and AGN activity, respectively, we independently disentangle the contributions of these two processes to the total soft X-ray emission. This decomposition generally agrees with L(sub x,SF) and L(sub x,AGN) at the 3 sigma level. In the absence of resolvable nuclear emission, our decomposition method provides a reasonable estimate of emission due to star formation in galaxies hosting type 2 AGNs.

  18. A Global Picture of AGN Winds

    NASA Technical Reports Server (NTRS)

    Kazanas, D.; Fukumura, K.

    2011-01-01

    We present a unified structure for accretion powered sources across their entire luminosity range from accreting galactic black holes to the most luminous quasars, with emphasis on AGN and their phenomenology. Central to this end is the notion of MHD winds launched from the accretion disks that power these objects. This work similar in spirit to that of Elvis of more that a decade ago, provides, on one hand, only the broadest characteristics of these objects, but on the other, also scaling laws that allow one to make contact with objects of different luminosity. The conclusion of this work is that AGN phenomenology can be accounted for in terms of dot(m), the wind mass flux in units of the Eddington value, the observer's inclination angle theta and alpha_OX the logarithmic slope between UV and X-ray flares. However given the well known correlation between alpha(sub ox) and UV Luminosity, we conclude that the AGN structure depends on only two parameters. The small number of model parameters hence suggests that an understanding of the global AGN properties maybe within reach.

  19. The AGN Luminosity Fraction in Galaxy Mergers

    NASA Astrophysics Data System (ADS)

    Dietrich, Jeremy; Weiner, Aaron; Ashby, Matthew; Martinez-Galarza, Juan Rafael; Smith, Howard Alan

    2017-01-01

    Galaxy mergers are key events in galaxy evolution, generally triggering massive starbursts and AGNs. However, in these chaotic systems, it is not yet known what fraction each of these two mechanisms contributes to the total luminosity. Here we measure and model spectral energy distributions (SEDs) using the Code for Investigating Galaxy Emission (CIGALE) in up to 33 broad bands from the UV to the far-IR for 23 IR-luminous galaxies to estimate the fraction of the bolometric IR luminosity that can be attributed to the AGN. The galaxies are split nearly evenly into two subsamples: late-stage mergers, found in the IRAS Revised Bright Galaxy Sample or Faint Source Catalog, and early-stage mergers found in the Spitzer Interacting Galaxy Sample. We find that the AGN contribution to the total IR luminosity varies greatly from system to system, from 0% up to ~90%, but is substantially greater in the later-stage and brighter mergers. This is consistent with what is known about galaxy evolution and the triggering of AGNs.The SAO REU program is funded in part by the National Science Foundation REU and Department of Defense ASSURE programs under NSF Grant no. 1262851, and by the Smithsonian Institution.

  20. Toward a Unified AGN Structure

    NASA Technical Reports Server (NTRS)

    Kazanas, Demosthenes; Fukumura, Keigo; Shrader, Chris; Behar, Ehud; Contopoulosa, Ioannis

    2012-01-01

    We present a unified model for the structure and appearance of accretion powered sources across their entire luminosity range from galactic X-ray binaries (XRB) to luminous quasars, with emphasis on AG N and their phenomenology. Central to this model is the notion of MHD winds launched by the accretion disks that power these objects. These winds provide the matter that manifests as blueshifted absorption features in the UV and X-ray spectra of a large fraction of these sources; furthermore, their density distribution in the poloidal plane determines their "appearance" (i.e. the column and velocity structure of these absorption features and the obscuration of the continuum source) as a function of the observer inclination angle (a feature to which INTEGRAL has made significant contributions). This work focuses on just the broadest characteristics of these objects; nonetheless, it provides scaling laws that allow one to reproduce within this model the properties of objects extending in luminosity from luminous quasars to XRBs. Our general conclusion is that the AGN phenomenology can be accounted for in terms of three parameters: The wind maSS flux in units of the Eddington value, m(dot), the observers' inclination angle Theta and the logarithmic slope between the 0/UV and X-ray fluxes alpha(sub ox); however because of a correlation between alpha(sub ox) and UV luminosity the number of significant parameters is two. The AGN correlations implied by this model appear to extend to and consistent with the XRB phenomenology, suggesting the presence of a truly unified underlying structure for accretion powered sources.

  1. Host Galaxy Properties of the Swift BAT Ultra Hard X-Ray Selected AGN

    NASA Technical Reports Server (NTRS)

    Koss, Michael; Mushotzky, Richard; Veilleux, Sylvain; Winter, Lisa M.; Baumgartner, Wayne; Tueller, Jack; Gehrels, Neil; Valencic, Lynne

    2011-01-01

    We have assembled the largest sample of ultra hard X-ray selected (14-195 keV) AGN with host galaxy optical data to date, with 185 nearby (z<0.05), moderate luminosity AGN from the Swift Burst Alert Telescope (BAT) sample. The BAT AGN host galaxies have intermediate optical colors (u -- r and g -- r) that are bluer than a comparison sample of inactive galaxies and optically selected AGN from the Sloan Digital Sky Survey (SDSS) which are chosen to have the same stellar mass. Based on morphological classifications from the RC3 and the Galaxy Zoo, the bluer colors of BAT AGN are mainly due to a higher fraction of mergers and massive spirals than in the comparison samples. BAT AGN in massive galaxies (log Stellar Mass >10.5) have a 5 to 10 times higher rate of spiral morphologies than in SDSS AGN or inactive galaxies. We also see enhanced far-IR emission in BAT AGN suggestive of higher levels of star formation compared to the comparison samples. BAT AGN are preferentially found in the most massive host galaxies with high concentration indexes indicative of large bulge-to-disk ratios and large supermassive black holes. The narrow-line (NL) BAT AGN have similar intrinsic luminosities as the SDSS NL Seyferts based on measurements of [O III] Lambda 5007. There is also a correlation between the stellar mass and X-ray emission. The BAT AGN in mergers have bluer colors and greater ultra hard X-ray emission compared to the BAT sample as whole. In agreement with the Unified Model of AGN, and the relatively unbiased nature of the BAT sources, the host galaxy colors and morphologies are independent of measures of obscuration such as X-ray column density or Seyfert type. The high fraction of massive spiral galaxies and galaxy mergers in BAT AGN suggest that host galaxy morphology is related to the activation and fueling of local AGN.

  2. Principles of the Unification of Our Agency

    ERIC Educational Resources Information Center

    Roth, Klas

    2011-01-01

    Do we need principles of the unification of our agency, our mode of acting? Immanuel Kant and Christine Korsgaard argue that the reflective structure of our mind forces us to have some conception of ourselves, others and the world--including our agency--and that it is through will and reason, and in particular principles of our agency, that we…

  3. Top quark mass in supersymmetric SO(10) unification

    SciTech Connect

    Hall, L.J. Physics Department, University of California, Berkeley, California 94720 ); Rattazzi, R.; Sarid, U. )

    1994-12-01

    The successful prediction of the weak mixing angle suggests that the effective theory beneath the grand unification scale is the minimal supersymmetric standard model (MSSM) with just two Higgs doublets. If we further assume that the unified gauge group contains SO(10), that the two light Higgs doublets lie mostly in a single irreducible SO(10) representation, and that the [ital t], [ital b], and [tau] masses originate in renormalizable Yukawa interactions of the form 1[bold 6][sub 3][ital scrO]1[bold 6][sub 3], then also the top quark mass can be predicted in terms of the MSSM parameters. To compute [ital m][sub [ital t

  4. An alternative NMSSM phenomenology with manifest perturbative unification

    SciTech Connect

    Hall, Lawrence; Barbieri, Riccardo; Pappadopulo, Duccio; Rychkov, Vyacheslav S.; Hall, Lawrence J.; Papaioannou, Anastasios Y.

    2007-12-18

    Can supersymmetric models with a moderate stop mass be made consistent with the negative Higgs boson searches at LEP, while keeping perturbative unification manifest? The NMSSM achieves this rather easily, but only if extra matter multiplets filling complete SU(5) representations are present at intermediate energies. As a concrete example which makes use of this feature, we give an analytic description of the phenomenology of a constrained NMSSM close to a Peccei-Quinn symmetry point. The related pseudo-Goldstone boson appears in decays of the Higgs bosons and possibly of the lightest neutralino, and itself decays into (b anti-b) and (tau anti-tau).

  5. Starburst or AGN Dominance in Submillimetre-Luminous Candidate AGN?

    NASA Astrophysics Data System (ADS)

    Coppin, Kristen; Pope, Alexandra; Menéndez-Delmestre, Karín; Alexander, David M.; Dunlop, James

    2010-06-01

    It is widely believed that ultraluminous infrared (IR) galaxies and active galactic nuclei (AGN) activity are triggered by galaxy interactions and merging, with the peak of activity occurring at z~2, where submillimetre galaxies are thousands of times more numerous than local ULIRGs. In this evolutionary picture, submillimetre galaxies (SMGs) would host an AGN, which would eventually grow a black hole (BH) strong enough to blow off all of the gas and dust leaving an optically luminous QSO. To probe this evolutionary sequence we have focussed on the `missing link' sources, which demonstrate both strong starburst (SB) and AGN signatures, in order to determine if the SB is the main power source even in SMGs when we have evidence that an AGN is present from their IRAC colours. The best way to determine if a dominant AGN is present is to look for their signatures in the mid-infrared with the Spitzer IRS, since often even deep X-ray observations miss identifying the presence of AGN in heavily dust-obscured SMGs. We present the results of our audit of the energy balance between star-formation and AGN within this special sub-population of SMGs-where the BH has grown appreciably to begin heating the dust emission.

  6. Multiwavelength Number Counts of AGN in the GOODS Fields

    NASA Astrophysics Data System (ADS)

    Urry, C. M.; Treister, E.; Chatzichristou, E. T.; Van Duyne, J.; Bauer, F. E.; Alexander, D. M.; Koekemoer, A. M.; Moustakas, L. A.; Brandt, W. N.; Grogin, N. A.; Bergeron, J.; Stern, D.; Chary, R.-R.; Conselice, C. J.; Cristiani, S.

    2004-05-01

    We model the X-ray, optical, and far-infrared flux distributions of AGN in the GOODS fields, starting from hard X-ray luminosity functions and spectral energy distributions appropriate to the unified scheme for AGN. The deep optical counts measured from HST ACS images can be well explained by a unified scheme that postulates roughly 3 times as many obscured as unobscured AGN. This scenario is consistent with the observed spectroscopic and photometric redshift distributions of the GOODS AGN once selection effects are considered. The previously reported discrepancy between observed spectroscopic redshift distributions and the predictions of population synthesis models for the X-ray background (which include a similarly large number of obscured AGN) is explained by bias against the most heavily obscured AGN in both X-ray surveys and optical spectroscopic samples. We present the model predictions for the number counts of AGN in the Spitzer MIPS 24 micron and IRAC 3.6-8 micron bands. The GOODS Spitzer observations will verify whether large numbers of obscured AGN are indeed present in the early Universe; these will be very bright far-infrared sources, including some, missed by X-ray observations, that look like ultraluminous infrared galaxies. Based on observations obtained with the NASA/ESA Hubble Space Telescope, which is operated by the Association of Universities for Research in Astronomy (AURA), Inc, under NASA contract NAS5-26555. This work was supported by NASA grants HST-GO-09425(.01-A,.13-A,.26-A); NSF CAREER award AST 99-83783; NASA contract number 1224666 issued by JPL/Caltech under NASA contract 1407; ASI grant I/R/088/02; and a Royal Society University Research Fellowship.

  7. Dark matter, mirror world, and E{sub 6} unification

    SciTech Connect

    Das, Ch. R.; Laperashvili, L. V.

    2009-02-15

    The idea that the ordinary (O) and mirror (M) worlds exist simultaneously is developed. It is shown that, in the case of a violated mirror parity (MP), the renormalization-group evolution of the coupling constants, which is represented in the O world by the dependence {alpha}{sub i}{sup -1} ({mu}) ({mu} is an energy variable), is not identical to the evolution of the coupling constants {alpha}'{sub i}{sup -1}({mu}) in the M world. Here, the index i labels the symmetry group under consideration, while a dash labels quantities defined in the M world. It is assumed that E{sup 6} unification predicted by superstring theory restores MP at the unification scale M{sub SGUT} {approx} 10{sup 18} GeV, this inevitably leading to the difference in the violation of E{sup 6} unification in the O and M worlds at lower energies: E{sup 6} {yields} SO(10) x U(1){sub Z} and E'{sub 6} {yields} SU(6)' x SU(2)'{sub Z}. Considering only asymptotically free theories, we present the evolution of all the inverse coupling constants {alpha}{sub i}{sup -1}({mu}) in the one-loop approximation. In dealing with the M world involving MP violation, we then arrive at the model of the accelerating expansion of our Universe, where the axion ('acceleron') belongs to the SU(2)'{sub Z} group of the M world. The coupling constant g'{sub Z}, which grows indefinitely at the scale {Lambda}'{sub Z} {approx} 10{sup -3} eV, is associated with this group. Within this theory, our Universe is in the false vacuum of the M world, in agreement with the phenomenologically observed cosmological constant of about (3 x 10{sup -3} eV){sup 4}.

  8. AGN Coronae through a Jet Perspective

    NASA Astrophysics Data System (ADS)

    King, Ashley L.; Lohfink, Anne; Kara, Erin

    2017-02-01

    This paper presents an in-depth look at the jet and coronal properties of 41 active galactic nuclei (AGNs). Utilizing the highest quality NuSTAR, XMM-Newton, and NRAO VLA Sky Survey 1.4 GHz data, we find that the radio Eddington luminosity inversely scales with X-ray reflection fraction, and positively scales with the distance between the corona and the reflected regions in the disk. We next investigate a model fit to the data that predicts the corona is outflowing and propagates into the large-scale jet. We find this model describes the data well and predicts that the corona has mildly relativistic velocities, 0.04< β < 0.40. We discuss our results in the context of disk–jet connections in AGNs.

  9. Supersymmetric grand unification with light color-triplet

    NASA Astrophysics Data System (ADS)

    Berezhiani, Lasha

    2012-05-01

    We construct a natural model of the supersymmetric SU (6) unification, in which the symmetry breaking, down to the standard model gauge group, results in the number of pseudo-Nambu-Goldstone superfields with interesting properties. Namely, besides the Higgs doublet-antidoublet pair which is responsible for the electroweak phase transition, the Nambu-Goldstone sector consists of multiplets in the anti- and fundamental representations of SU (5). While being strictly massless in the supersymmetric limit, they acquire the weak scale masses as a result of its breaking. The color-triplet components of this light sector could, in principle, mediate an unacceptably fast proton decay; however, because of the natural TeV /MGUT suppression of the Yukawa couplings to the light quarks and leptons, their existence is compatible with the experimental bound on proton lifetime. This suppression is made further interesting, since it results in the lifetime, of the lightest of the above-mentioned colored particles from 1 s to 1 day, long enough for it to appear stable in the detector. Furthermore, we argue that the accommodation of the color-triplet pseudo-Nambu-Goldstones, without fine-tuning or contradicting observations, implies SU (6) unification.

  10. Unification and mass spectrum in a B-L extended MSSM

    SciTech Connect

    Hernandez-Pinto, R. J.; Perez-Lorenzana, A.

    2009-04-20

    The simplest B-L extension of the minimum supersymmetric standard model (MSSM) may change some of the conceptions about the path for gauge unification as well as to affect the predicted spectrum of the supersymmetric particles at low energy. We present our results for the running of gauge coupling constants and mass parameter in this context.

  11. Vertical datum unification for the International Height Reference System (IHRS)

    NASA Astrophysics Data System (ADS)

    Sánchez, Laura; Sideris, Michael G.

    2017-01-01

    SUMMARYThe International Association of Geodesy released in July 2015 a resolution for the definition and realisation of an International Height Reference System (IHRS). According to this resolution, the IHRS coordinates are potential differences referring to the equipotential surface of the Earth's gravity field realised by the conventional value W0 = 62 636 853.4 m2s-2. A main component of the IHRS realisation is the integration of the existing height systems into the global one; i.e. existing vertical coordinates should be referred to one and the same reference level realised by the conventional W0. This procedure is known as vertical datum <span class="hlt">unification</span> and its main result are the vertical datum parameters, i.e., the potential differences between the local and the global reference levels. In this paper, we rigorously derive the observation equations for the vertical datum <span class="hlt">unification</span> in terms of potential quantities based on the geodetic boundary value problem (GBVP) approach. Those observation equations are then empirically evaluated for the vertical datum <span class="hlt">unification</span> of the North American and South American height systems. In the first case, simulations performed in North America provide numerical estimates about the impact of omission errors and direct and indirect effects on the vertical datum parameters. In the second case, a combination of local geopotential numbers, ITRF coordinates, satellite altimetry observations, tide gauge registrations and high-resolution gravity field <span class="hlt">models</span> is performed to estimate the level differences between the South American height systems and the global level W0. Results show that indirect effects vanish when a satellite-only gravity field <span class="hlt">model</span> with a degree higher than n ≥ 180 is used for the solution of the GBVP. However, the component derived from satellite-only global gravity <span class="hlt">models</span> has to be refined with terrestrial gravity data to minimise the omission error and its effect on the vertical datum parameter</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/883237','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/883237"><span>Grand <span class="hlt">Unification</span> as a Bridge Between String Theory and Phenomenology</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Pati, Jogesh C.</p> <p>2006-06-09</p> <p>In the first part of the talk, I explain what empirical evidence points to the need for having an effective grand <span class="hlt">unification</span>-like symmetry possessing the symmetry SU(4)-color in 4D. If one assumes the premises of a future predictive theory including gravity--be it string/M theory or a reincarnation--this evidence then suggests that such a theory should lead to an effective grand <span class="hlt">unification</span>-like symmetry as above in 4D, near the string-GUT-scale, rather than the standard <span class="hlt">model</span> symmetry. Advantages of an effective supersymmetric G(224) = SU(2){sub L} x SU(2){sub R} x SU(4){sup c} or SO(10) symmetry in 4D in explaining (1) observed neutrino oscillations, (2) baryogenesis via leptogenesis, and (3) certain fermion mass-relations are noted. And certain distinguishing tests of a SUSY G(224) or SO(10)-framework involving CP and flavor violations (as in {mu} {yields} e{gamma}, {tau} {yields} {mu}{gamma}, edm's of the neutron and the electron) as well as proton decay are briefly mentioned. Recalling some of the successes we have had in our understanding of nature so far, and the current difficulties of string/M theory as regards the large multiplicity of string vacua, some comments are made on the traditional goal of understanding vis a vis the recently evolved view of landscape and anthropism.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006IJMPD..15.1677P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006IJMPD..15.1677P"><span>Grand <span class="hlt">Unification</span> as a Bridge Between String Theory and Phenomenology</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pati, Jogesh C.</p> <p></p> <p>In the first part of this paper, we explain what empirical evidence points to the need for having an effective grand <span class="hlt">unification</span>-like symmetry possessing the symmetry SU(4)-color in 4D. If one assumes the premises of a future predictive theory including gravity — be it string/M-theory or a reincarnation — this evidence then suggests that such a theory should lead to an effective grand <span class="hlt">unification</span>-like symmetry as above in 4D, near the string-GUT-scale, rather than the standard <span class="hlt">model</span> symmetry. Advantages of an effective supersymmetric G(224) = SU(2)L × SU(2)R × SU(4)c or SO(10) symmetry in 4D in explaining (i) observed neutrino oscillations, (ii) baryogenesis via leptogenesis, and (iii) certain fermion mass-relations are noted. And certain distinguishing tests of a SUSY G(224) or SO(10)-framework involving CP and flavor violations (as in μ → eγ, τ → μγ, edm's of the neutron and the electron) as well as proton decay are briefly mentioned. Recalling some of the successes we have had in our understanding of nature so far, and the current difficulties of string/M-theory as regards the large multiplicity of string vacua, some comments are made on the traditional goal of understanding vis a vis the recently evolved view of landscape and anthropism.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20900785','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20900785"><span>Searching for Dark Matter in <span class="hlt">Unification</span> <span class="hlt">Models</span>: A Hint from Indirect Sensitivities towards Future Signals in Direct Detection and B-decays</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Olive, Keith A.</p> <p>2006-11-28</p> <p>A comparison is made between accelerator and direct detection constraints in constrained versions of the minimal supersymmetric standard <span class="hlt">model</span>. <span class="hlt">Models</span> considered are based on mSUGRA, where scalar and gaugino masses are unified at the GUT scale. In addition, the mSUGRA relation between the (unified) A and B parameters is assumed, as is the relation between m0 and gravitino mass. Also considered are <span class="hlt">models</span> where the latter two conditions are dropped (the CMSSM), and a less constrained version where the Higgs soft masses are not unified at the GUT scale (the NUHM)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1004918','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1004918"><span>Three years of Swift/BAT Survey of <span class="hlt">AGN</span>: Reconciling Theory and Observations?</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Burlon, D.; Ajello, M.; Greiner, J.; Comastri, A.; Merloni, A.; Gehrels, N.; /NASA, Goddard</p> <p>2011-02-07</p> <p>It is well accepted that unabsorbed as well as absorbed <span class="hlt">AGN</span> are needed to explain the nature and the shape of the Cosmic X-ray background, even if the fraction of highly absorbed objects (dubbed Compton-thick sources) substantially still escapes detection. We derive and analyze the absorption distribution using a complete sample of <span class="hlt">AGN</span> detected by Swift-BAT in the first three years of the survey. The fraction of Compton-thick <span class="hlt">AGN</span> represents only 4.6% of the total <span class="hlt">AGN</span> population detected by Swift-BAT. However, we show that once corrected for the bias against the detection of very absorbed sources the real intrinsic fraction of Compton-thick <span class="hlt">AGN</span> is 20{sub -6}{sup +9}%. We proved for the first time (also in the BAT band) that the anti-correlation of the fraction of absorbed <span class="hlt">AGN</span> and luminosity it tightly connected to the different behavior of the luminosity functions (XLFs) of absorbed and unabsorbed <span class="hlt">AGN</span>. This points towards a difference between the two subsamples of objects with absorbed <span class="hlt">AGN</span> being, on average, intrinsically less luminous than unobscured ones. Moreover the XLFs show that the fraction of obscured <span class="hlt">AGN</span> might also decrease at very low luminosity. This can be successfully interpreted in the framework of a disk cloud outflow scenario as the disappearance of the obscuring region below a critical luminosity. Our results are discussed in the framework of population synthesis <span class="hlt">models</span> and the origin of the Cosmic X-ray Background.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003HEAD....7.0902B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003HEAD....7.0902B"><span><span class="hlt">AGN</span> Observations with STACEE</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bramel, D. A.; Boone, L. M.; Carson, J.; Chae, E.; Covault, C. E.; Fortin, P.; Gingrich, D. M.; Hanna, D. S.; Hinton, J. A.; Mukherjee, R.; Mueller, C.; Ong, R. A.; Ragan, K.; Scalzo, R. A.; Schuette, D. R.; Theoret, C. G.; Williams, D. A.; Wong, J.; Zweerink, J.</p> <p>2003-03-01</p> <p>The Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE) is a gamma-ray detector designed to study astrophysical sources at energies between 50 and 500 GeV. It uses 64 large, steerable mirrors at the National Solar Tower Test Facility near Albuquerque, NM, USA to collect Cherenkov light from extended air showers and concentrate it onto an array of photomultiplier tubes. The large light-collection area gives it a lower energy threshold than imaging-type Cherenkov detectors. STACEE is now fully operational, and we report here on the performance of the complete STACEE instrument, as well as preliminary results of recent observations of several <span class="hlt">AGN</span> targets. This work was supported in part by the National Science Foundation (under Grant Numbers PHY-9983836, PHY-0070927, and PHY-0070953), the Natural Sciences and Engineering Research Council, Le Fond Quebecois de la Recherche sur la Nature et les Technologies (FQRNT), the Research Corporation, and the California Space Institute. CEC is a Cottrell Scholar of the Research Corporation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008ASPC..401..235B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008ASPC..401..235B"><span>High-resolution Interferometric Observations of Nova RS Ophiuchi and a Proposed <span class="hlt">Unification</span> <span class="hlt">Model</span> for Persistent Dust Creation in Recurrent Novae</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barry, R. K.; Danchi, W. C.</p> <p>2008-12-01</p> <p>We review observations of nova RS Ophiuchi using long-baseline near-infrared and mid-infrared interferometry at three observatories: the Keck Interferometer in the Nulling mode (KIN), the Palomar Testbed Interferometer (PTI), and the Infrared and Optical Telescope Array (IOTA). We discuss these observations in the context of a unifying <span class="hlt">model</span> of the system that includes an increase in density in the plane of the orbit of the two stars created by a spiral shock wave caused by the motion of the stars through the cool wind of the red giant star. We discuss how recent observations using the Spitzer Space Telescope and the VLTI support this proposed <span class="hlt">model</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016MPLA...3130046C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MPLA...3130046C"><span>Quanta of geometry and <span class="hlt">unification</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chamseddine, Ali H.</p> <p>2016-11-01</p> <p>This is a tribute to Abdus Salam’s memory whose insight and creative thinking set for me a role <span class="hlt">model</span> to follow. In this contribution I show that the simple requirement of volume quantization in spacetime (with Euclidean signature) uniquely determines the geometry to be that of a noncommutative space whose finite part is based on an algebra that leads to Pati-Salam grand unified <span class="hlt">models</span>. The Standard <span class="hlt">Model</span> corresponds to a special case where a mathematical constraint (order one condition) is satisfied. This provides evidence that Salam was a visionary who was generations ahead of his time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Berlin+AND+Wall&id=EJ735623','ERIC'); return false;" href="http://eric.ed.gov/?q=Berlin+AND+Wall&id=EJ735623"><span><span class="hlt">Unification</span> of Theoretical <span class="hlt">Models</span> of Academic Self-Concept/Achievement Relations: Reunification of East and West German School Systems after the Fall of the Berlin Wall</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Marsh, Herbert W.; Koller, Olaf</p> <p>2004-01-01</p> <p>Longitudinal data (five waves) from large cohorts of 7th grade students in East Germany ("n"=2,119) and West Germany ("n"=1,928) were collected from the start of the reunification of the school systems following the fall of the Berlin Wall. Here we integrate the two major theoretical <span class="hlt">models</span> of relations between academic…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016A%26A...588A..78B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016A%26A...588A..78B"><span><span class="hlt">AGN</span> host galaxy mass function in COSMOS. Is <span class="hlt">AGN</span> feedback responsible for the mass-quenching of galaxies?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bongiorno, A.; Schulze, A.; Merloni, A.; Zamorani, G.; Ilbert, O.; La Franca, F.; Peng, Y.; Piconcelli, E.; Mainieri, V.; Silverman, J. D.; Brusa, M.; Fiore, F.; Salvato, M.; Scoville, N.</p> <p>2016-04-01</p> <p>We investigate the role of supermassive black holes in the global context of galaxy evolution by measuring the host galaxy stellar mass function (HGMF) and the specific accretion rate, that is, λSAR, the distribution function (SARDF), up to z ~ 2.5 with ~1000 X-ray selected <span class="hlt">AGN</span> from XMM-COSMOS. Using a maximum likelihood approach, we jointly fit the stellar mass function and specific accretion rate distribution function, with the X-ray luminosity function as an additional constraint. Our best-fit <span class="hlt">model</span> characterizes the SARDF as a double power-law with mass-dependent but redshift-independent break, whose low λSAR slope flattens with increasing redshift while the normalization increases. This implies that for a given stellar mass, higher λSAR objects have a peak in their space density at earlier epoch than the lower λSAR objects, following and mimicking the well-known <span class="hlt">AGN</span> cosmic downsizing as observed in the <span class="hlt">AGN</span> luminosity function. The mass function of active galaxies is described by a Schechter function with an almost constant M∗⋆ and a low-mass slope α that flattens with redshift. Compared to the stellar mass function, we find that the HGMF has a similar shape and that up to log (M⋆/M⊙) ~ 11.5, the ratio of <span class="hlt">AGN</span> host galaxies to star-forming galaxies is basically constant (~10%). Finally, the comparison of the <span class="hlt">AGN</span> HGMF for different luminosity and specific accretion rate subclasses with a previously published phenomenological <span class="hlt">model</span> prediction for the "transient" population, which are galaxies in the process of being mass-quenched, reveals that low-luminosity <span class="hlt">AGN</span> do not appear to be able to contribute significantly to the quenching and that at least at high masses, that is, M⋆ > 1010.7 M⊙, feedback from luminous <span class="hlt">AGN</span> (log Lbol ≳ 46 [erg/s]) may be responsible for the quenching of star formation in the host galaxy.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21504932','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21504932"><span>Radion and Higgs masses in gauge-Higgs <span class="hlt">unification</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sakamura, Yutaka</p> <p>2011-02-01</p> <p>We evaluate the radion and Higgs masses in the gauge-Higgs <span class="hlt">unification</span> <span class="hlt">models</span> on the warped geometry, in which the modulus is stabilized by the Casimir energy. We analyze the one-loop effective potential and clarify the dependences of those masses on the Wilson line phase {theta}{sub H}. The radion mass varies 1-30 GeV for 0.06{<=}sin{theta}{sub H{<=}}0.3, while the Higgs mass is 150-200 GeV and depends on {theta}{sub H} only logarithmically. The radion couplings to the standard <span class="hlt">model</span> particles are sensitive to the warp factor, and are too small to detect at colliders in the region where the five-dimensional description is valid.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997hecn.confE...8M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997hecn.confE...8M"><span><span class="hlt">AGN</span> jets as pion factories</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mannheim, Karl</p> <p></p> <p>There has been a dramatic revolution in gamma-ray astronomy throughout the last few years. Beginning with the discovery made by the spark chamber EGRET on board the Compton Gamma Ray Observatory that <span class="hlt">AGN</span> with jets are the most powerful quasi-steady gamma-ray sources in the Universe, air-Cerenkov telescopes have soon after succeeded in detecting gamma-rays up to TeV energies. In the last year, it has become clear that these <span class="hlt">AGN</span> emit photons even up to 10 TeV and more. This is a strong indication for proton acceleration going on in them, since protons owing to their large mass suffer weaker energy losses than electrons and can thus reach higher energies. Nucleons escaping from the <span class="hlt">AGN</span> jets contribute to the local flux of cosmic rays at highest energies. If <span class="hlt">AGN</span> produce the diffuse gamma-ray background, they would also be able to produce all the cosmic rays above the ankle in the local spectrum. The majority of <span class="hlt">AGN</span> resides at large distances, indicated by their cosmological redshifts, and can therefore not be seen through the fog of electron-positron pairs which they produce interacting with diffuse infrared radiation from the era of galaxy formation. To observe the cosmic accelerators at large redshifts, neutrino observations are required. It is important to understand the astrophysical neutrino sources in order to be able to recognize signatures of new physics, e.g. due to decaying or annihilating particles from the early phases of the Universe.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013MNRAS.436.2346B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013MNRAS.436.2346B"><span>Inverse Compton X-ray signature of <span class="hlt">AGN</span> feedback</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bourne, Martin A.; Nayakshin, Sergei</p> <p>2013-12-01</p> <p>Bright <span class="hlt">AGN</span> frequently show ultrafast outflows (UFOs) with outflow velocities vout ˜ 0.1c. These outflows may be the source of <span class="hlt">AGN</span> feedback on their host galaxies sought by galaxy formation <span class="hlt">modellers</span>. The exact effect of the outflows on the ambient galaxy gas strongly depends on whether the shocked UFOs cool rapidly or not. This in turn depends on whether the shocked electrons share the same temperature as ions (one-temperature regime, 1T) or decouple (2T), as has been recently suggested. Here we calculate the inverse Compton spectrum emitted by such shocks, finding a broad feature potentially detectable either in mid-to-high energy X-rays (1T case) or only in the soft X-rays (2T). We argue that current observations of <span class="hlt">AGN</span> do not seem to show evidence for the 1T component. The limits on the 2T emission are far weaker, and in fact it is possible that the observed soft X-ray excess of <span class="hlt">AGN</span> is partially or fully due to the 2T shock emission. This suggests that UFOs are in the energy-driven regime outside the central few pc, and must pump considerable amounts of not only momentum but also energy into the ambient gas. We encourage X-ray observers to look for the inverse Compton components calculated here in order to constrain <span class="hlt">AGN</span> feedback <span class="hlt">models</span> further.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=bernhard&pg=2&id=ED450104','ERIC'); return false;" href="http://eric.ed.gov/?q=bernhard&pg=2&id=ED450104"><span>Education in Germany since <span class="hlt">Unification</span>. Oxford Studies in Comparative Education.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Phillips, David, Ed.</p> <p></p> <p>This collection of papers discusses issues related to education in Germany since its <span class="hlt">unification</span>. The papers include: "The Legacy of <span class="hlt">Unification</span>" (David Phillips); "Change and Continuity in Education After the 'Wende'" (E. J. Neather); "A Study of Teachers' Perceptions in Brandenburg 'Gesamtschulen'" (Stephanie…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21304880','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21304880"><span>Heavily Obscured <span class="hlt">AGN</span> with SIMBOL-X</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ceca, R. Della; Caccianiga, A.; Severgnini, P.</p> <p>2009-05-11</p> <p>By comparing an optically selected sample of narrow lines <span class="hlt">AGN</span> with an X-ray selected sample of <span class="hlt">AGN</span> we have recently derived an estimate of the intrinsic (i.e. before absorption) 2-10 keV luminosity function (XLF) of Compton Thick <span class="hlt">AGNs</span>. We will use this XLF to derive the number of Compton Thick <span class="hlt">AGN</span> that will be found in the SIMBOL-X survey(s)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AIPC.1126..219D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AIPC.1126..219D"><span>Heavily Obscured <span class="hlt">AGN</span> with SIMBOL-X</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Della Ceca, R.; Caccianiga, A.; Severgnini, P.</p> <p>2009-05-01</p> <p>By comparing an optically selected sample of narrow lines <span class="hlt">AGN</span> with an X-ray selected sample of <span class="hlt">AGN</span> we have recently derived an estimate of the intrinsic (i.e. before absorption) 2-10 keV luminosity function (XLF) of Compton Thick <span class="hlt">AGNs</span>. We will use this XLF to derive the number of Compton Thick <span class="hlt">AGN</span> that will be found in the SIMBOL-X survey(s).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014NuPhS.251...22M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014NuPhS.251...22M"><span>Symmetry-cum-<span class="hlt">Unification</span> in physical theories</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mitra, A. N.</p> <p>2014-06-01</p> <p>A new kind of duality in physical sciences-involving Symmetry (S)on the one hand and <span class="hlt">Unification</span>(U) on the other- is proposed, wherein the two partners obey, not the traditional feature of mutual incompatibility of two canonically conjugate variables, but rather are bound by a cause-effect type of relationship, albeit at a probabilistic level. While a precise mathematical formulation of such relationship is still a distant goal, the possible impact of this new kind of duality on the growth of physical theories vis-a-vis experiment is envisaged.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AAS...22925037K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AAS...22925037K"><span>Searching for Short Term Variable Active Galactic Nuclei: A Vital Step Towards Using <span class="hlt">AGN</span> as Standard Candles</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kilts, Kelly; Gorjian, Varoujan; Rutherford, Thomas; Kohrs, Russell; Urbanowski, Vincent; Bellusci, Nina; Horton, Savannah; Jones, Dana; Jones, Kaytlyn; Pawelski, Peter; Tranum, Haley; Zhang, Emily</p> <p>2017-01-01</p> <p>Current <span class="hlt">models</span> for accretion disk sizes of active galactic nuclei (<span class="hlt">AGN</span>) do not match the limited observational data available, so there is an active need from the <span class="hlt">modeling</span> community for many more accretion disk/dusty torus reverberation mapping campaigns with which to better calibrate <span class="hlt">models</span>. Since short term variable <span class="hlt">AGN</span> can be more easily monitored for reverberation mapping than long term variable <span class="hlt">AGN</span>, they can begin to provide data more quickly. This project looked for short term variable <span class="hlt">AGN</span> in the Young Stellar Object Variability (YSOVAR) survey conducted using the Spitzer Space Telescope. The YSOVAR survey targeted 12 nearby star forming regions for repeated observations. Potential <span class="hlt">AGN</span> from the YSOVAR data were first selected by color ([3.6] - [4.5] > 0.4) and then by magnitude (m < 14) based on previous Spitzer surveys of known <span class="hlt">AGN</span>. Since <span class="hlt">AGN</span> share some similar color characteristics with young stars, images of each YSOVAR region were viewed to remove potential objects near concentrations of known young stellar objects since these were likely also YSOs. The spectral energy distribution (SED) for each remaining potential <span class="hlt">AGN</span> was then examined for <span class="hlt">AGN</span> like characteristics. Several potential short term variable <span class="hlt">AGN</span> were found.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JHEP...05..185E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JHEP...05..185E"><span>Induced gravity II: grand <span class="hlt">unification</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Einhorn, Martin B.; Jones, D. R. Timothy</p> <p>2016-05-01</p> <p>As an illustration of a renormalizable, asymptotically-free <span class="hlt">model</span> of induced gravity, we consider an SO(10) gauge theory interacting with a real scalar multiplet in the adjoint representation. We show that dimensional transmutation can occur, spontaneously breaking SO(10) to SU(5)⊗U(1), while inducing the Planck mass and a positive cosmological constant, all proportional to the same scale v. All mass ratios are functions of the values of coupling constants at that scale. Below this scale (at which the Big Bang may occur), the <span class="hlt">model</span> takes the usual form of Einstein-Hilbert gravity in de Sitter space plus calculable corrections. We show that there exist regions of parameter space in which the breaking results in a local minimum of the effective action giving a positive dilaton (mass)2 from two-loop corrections associated with the conformal anomaly. Furthermore, unlike the singlet case we considered previously, some minima lie within the basin of attraction of the ultraviolet fixed point. Moreover, the asymptotic behavior of the coupling constants also lie within the range of convergence of the Euclidean path integral, so there is hope that there will be candidates for sensible vacua. Although open questions remain concerning unitarity of all such renormalizable <span class="hlt">models</span> of gravity, it is not obvious that, in curved backgrounds such as those considered here, unitarity is violated. In any case, any violation that may remain will be suppressed by inverse powers of the reduced Planck mass.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AAS...22143007E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AAS...22143007E"><span>Time-Dependent Photoionization of Gas Outflows in <span class="hlt">AGN</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Elhoussieny, Ehab E.; Bautista, M.; Garcia, J.; Kallman, T. R.</p> <p>2013-01-01</p> <p>Gas outflows are fundamental components of Active Galactic Nuclei (<span class="hlt">AGN</span>) activity. Time-variability of ionizing radiation, which is characteristic of <span class="hlt">AGN</span> in various different time scales, may produce non-equilibrium photoionization conditions over a significant fraction of the flow and yields supersonically moving cooling/heating fronts. These fast fronts create pressure imbalances that can only be resolved by fragmentation of the flow and acceleration of such fragments. This mechanism can explain the kinematic structure of low ionization BAL systems (FeLoBAL). This mechanism may also have significant effects on other types of outflows given the wide range of variability time scales in <span class="hlt">AGN</span>. We will study these effects in detail by constructing time-dependent photoionization <span class="hlt">models</span> of the outflows and incorporating these <span class="hlt">models</span> into radiative-hydrodynamic simulations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008NatPh...4..404L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008NatPh...4..404L"><span>A thermodynamic <span class="hlt">unification</span> of jamming</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lu, Kevin; Brodsky, E. E.; Kavehpour, H. P.</p> <p>2008-05-01</p> <p>Fragile materials ranging from sand to fire retardant to toothpaste are able to exhibit both solid and fluid-like properties across the jamming transition. Unlike ordinary fusion, systems of grains, foams and colloids jam and cease to flow under conditions that still remain unknown. Here, we quantify jamming using a thermodynamic approach by accounting for the structural ageing and the shear-induced compressibility of dry sand. Specifically, the jamming threshold is defined using a non-thermal temperature that measures the `fluffiness' of a granular mixture. The thermodynamic <span class="hlt">model</span>, cast in terms of pressure, temperature and free volume, also successfully predicts the entropic data of five molecular glasses. Notably, the predicted configurational entropy averts the Kauzmann paradox-an unresolved crisis where the configurational entropy becomes negative-entirely. Without any free parameters, the proposed equation-of-state also governs the mechanism of shear banding and the associated features of shear softening and thickness invariance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ApJ...805...80C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ApJ...805...80C"><span>Analyses of the Variability Asymmetry of Kepler <span class="hlt">AGNs</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Xiao-Yang; Wang, Jun-Xian</p> <p>2015-05-01</p> <p>The high-quality light curves from the Kepler space telescope make it possible to analyze the optical variability of active galactic nuclei (<span class="hlt">AGNs</span>) with unprecedented time resolution. Studying the asymmetry in variations could provide independent constraints on physical <span class="hlt">models</span> for <span class="hlt">AGN</span> variability. In this paper, we use Kepler observations of 19 sources to perform analyses of the variability asymmetry of <span class="hlt">AGNs</span>. We apply smoothing correction to light curves to deduct their bias toward high-frequency variability asymmetry caused by long-term variations that have been poorly sampled due to the limited length of light curves. A parameter β based on structure functions is introduced to quantitively describe the asymmetry and its uncertainty is measured using extensive Monte Carlo simulations. Individual sources show no evidence of asymmetry at timescales of 1˜ 20 days and there is no general trend toward positive or negative asymmetry over the whole sample. Stacking the data from all 19 <span class="hlt">AGNs</span>, we derive an averaged \\bar{β } of 0.00 ± 0.03 and -0.02 ± 0.04 over timescales of 1 ˜ 5 days and 5 ˜ 20 days, respectively, which are statistically consistent with zero. Quasars and Seyfert galaxies show similar asymmetry parameters. Our results indicate that short-term optical variations in <span class="hlt">AGNs</span> are highly symmetric.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015toru.conf..O13M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015toru.conf..O13M"><span>First X-ray Statistical Tests for Clumpy Torii <span class="hlt">Models</span>: Constraints from RXTE monitoring of Seyfert <span class="hlt">AGN</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Markowitz, A.</p> <p>2015-09-01</p> <p>We summarize two papers providing the first X-ray-derived statistical constraints for both clumpy-torus <span class="hlt">model</span> parameters and cloud ensemble properties. In Markowitz, Krumpe, & Nikutta (2014), we explored multi-timescale variability in line-of-sight X-ray absorbing gas as a function of optical classification. We examined 55 Seyferts monitored with the Rossi X-ray Timing Explorer, and found in 8 objects a total of 12 eclipses, with durations between hours and years. Most clouds are commensurate with the outer portions of the BLR, or the inner regions of infrared-emitting dusty tori. The detection of eclipses in type Is disfavors sharp-edged tori. We provide probabilities to observe a source undergoing an absorption event for both type Is and IIs, yielding constraints in [N_0, sigma, i] parameter space. In Nikutta et al., in prep., we infer that the small cloud angular sizes, as seen from the SMBH, imply the presence of >10^7 clouds in BLR+torus to explain observed covering factors. Cloud size is roughly proportional to distance from the SMBH, hinting at the formation processes (e.g. disk fragmentation). All observed clouds are sub-critical with respect to tidal disruption; self-gravity alone cannot contain them. External forces (e.g. magnetic fields, ambient pressure) are needed to contain them, or otherwise the clouds must be short-lived. Finally, we infer that the radial cloud density distribution behaves as 1/r^{0.7}, compatible with VLTI observations. Our results span both dusty and non-dusty clumpy media, and probe <span class="hlt">model</span> parameter space complementary to that for short-term eclipses observed with XMM-Newton, Suzaku, and Chandra.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JPhA...50k5401L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JPhA...50k5401L"><span><span class="hlt">Unification</span> mechanism for gauge and spacetime symmetries</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>László, András</p> <p>2017-03-01</p> <p>A group theoretical mechanism for <span class="hlt">unification</span> of local gauge and spacetime symmetries is introduced. No-go theorems prohibiting such <span class="hlt">unification</span> are circumvented by slightly relaxing the usual requirement on the gauge group: only the so called Levi factor of the gauge group needs to be compact semisimple, not the entire gauge group. This allows a non-conventional supersymmetry-like extension of the gauge group, glueing together the gauge and spacetime symmetries, but not needing any new exotic gauge particles. It is shown that this new relaxed requirement on the gauge group is nothing but the minimal condition for energy positivity. The mechanism is demonstrated to be mathematically possible and physically plausible on a \\text{U}(1) based gauge theory setting. The unified group, being an extension of the group of spacetime symmetries, is shown to be different than that of the conventional supersymmetry group, thus overcoming the McGlinn and Coleman–Mandula no-go theorems in a non-supersymmetric way.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA520956','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA520956"><span><span class="hlt">AGN</span> Feedback in Clusters of Galaxies</span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p>2010-01-01</p> <p>bubbles created by the radio lobes evacuating regions of the ICM vary widely from a few kpc (e.g. Abell 262 [21, 22]) to hundreds of kpc (e.g. MS0735.6...diameters of approximately 200 kpc . The total energy injection required to inflate the cavities and produce the ob- served shocks is 6 × 1061 erg...cluster center, and these are <span class="hlt">modeled</span> as shocks in [32] based on the earlier 163 ksec dataset. These features are at 31 and 46 kpc from the <span class="hlt">AGN</span> and the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015A%26A...575A..22M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015A%26A...575A..22M"><span>Anatomy of the <span class="hlt">AGN</span> in NGC 5548. I. A global <span class="hlt">model</span> for the broadband spectral energy distribution</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mehdipour, M.; Kaastra, J. S.; Kriss, G. A.; Cappi, M.; Petrucci, P.-O.; Steenbrugge, K. C.; Arav, N.; Behar, E.; Bianchi, S.; Boissay, R.; Branduardi-Raymont, G.; Costantini, E.; Ebrero, J.; Di Gesu, L.; Harrison, F. A.; Kaspi, S.; De Marco, B.; Matt, G.; Paltani, S.; Peterson, B. M.; Ponti, G.; Pozo Nuñez, F.; De Rosa, A.; Ursini, F.; de Vries, C. P.; Walton, D. J.; Whewell, M.</p> <p>2015-03-01</p> <p>An extensive multi-satellite campaign on NGC 5548 has revealed this archetypal Seyfert-1 galaxy to be in an exceptional state of persistent heavy absorption. Our observations taken in 2013-2014 with XMM-Newton, Swift, NuSTAR, INTEGRAL, Chandra, HST and two ground-based observatories have together enabled us to establish that this unexpected phenomenon is caused by an outflowing stream of weakly ionised gas (called the obscurer), extending from the vicinity of the accretion disk to the broad-line region. In this work we present the details of our campaign and the data obtained by all the observatories. We determine the spectral energy distribution of NGC 5548 from near-infrared to hard X-rays by establishing the contribution of various emission and absorption processes taking place along our line of sight towards the central engine. We thus uncover the intrinsic emission and produce a broadband continuum <span class="hlt">model</span> for both obscured (average summer 2013 data) and unobscured (<2011) epochs of NGC 5548. Our results suggest that the intrinsic NIR/optical/UV continuum is a single Comptonised component with its higher energy tail creating the "softX-ray excess". This component is compatible with emission from a warm, optically-thick corona as part of the inner accretion disk. We then investigate the effects of the continuum on the ionisation balance and thermal stability of photoionised gas for unobscured and obscured epochs. Appendix A is available in electronic form at http://www.aanda.org</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22518960','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22518960"><span>THE <span class="hlt">UNIFICATION</span> OF POWERFUL QUASARS AND RADIO GALAXIES AND THEIR RELATION TO OTHER MASSIVE GALAXIES</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Podigachoski, Pece; Barthel, Peter; Haas, Martin; Leipski, Christian; Wilkes, Belinda</p> <p>2015-06-10</p> <p>The <span class="hlt">unification</span> <span class="hlt">model</span> for powerful radio galaxies (RGs) and radio-loud quasars postulates that these objects are intrinsically the same but viewed along different angles. Herschel Space Observatory data permit the assessment of that <span class="hlt">model</span> in the far-infrared spectral window. We analyze photometry from Spitzer and Herschel for the distant 3CR hosts, and find that RGs and quasars have different mid-infrared, but indistinguishable far-infrared colors. Both these properties, the former being orientation dependent and the latter orientation invariant, are in line with expectations from the <span class="hlt">unification</span> <span class="hlt">model</span>. Adding powerful radio-quiet active galaxies and typical massive star-forming (SF) galaxies to the analysis, we demonstrate that infrared colors not only provide an orientation indicator, but can also distinguish active from SF galaxies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014atp..prop...22K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014atp..prop...22K"><span>Warm Absorber Diagnostics of <span class="hlt">AGN</span> Dynamics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kallman, Timothy</p> <p></p> <p>Warm absorbers and related phenomena are observable manifestations of outflows or winds from active galactic nuclei (<span class="hlt">AGN</span>) that have great potential value. Understanding <span class="hlt">AGN</span> outflows is important for explaining the mass budgets of the central accreting black hole, and also for understanding feedback and the apparent co-evolution of black holes and their host galaxies. In the X-ray band warm absorbers are observed as photoelectric absorption and resonance line scattering features in the 0.5-10 keV energy band; the UV band also shows resonance line absorption. Warm absorbers are common in low luminosity <span class="hlt">AGN</span> and they have been extensively studied observationally. They may play an important role in <span class="hlt">AGN</span> feedback, regulating the net accretion onto the black hole and providing mechanical energy to the surroundings. However, fundamental properties of the warm absorbers are not known: What is the mechanism which drives the outflow?; what is the gas density in the flow and the geometrical distribution of the outflow?; what is the explanation for the apparent relation between warm absorbers and the surprising quasi-relativistic 'ultrafast outflows' (UFOs)? We propose a focused set of <span class="hlt">model</span> calculations that are aimed at synthesizing observable properties of warm absorber flows and associated quantities. These will be used to explore various scenarios for warm absorber dynamics in order to answer the questions in the previous paragraph. The guiding principle will be to examine as wide a range as possible of warm absorber driving mechanisms, geometry and other properties, but with as careful consideration as possible to physical consistency. We will build on our previous work, which was a systematic campaign for testing important class of scenarios for driving the outflows. We have developed a set of tools that are unique and well suited for dynamical calculations including radiation in this context. We also have state-of-the-art tools for generating synthetic spectra, which are</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015IAUGA..2257803R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015IAUGA..2257803R"><span>The Close <span class="hlt">AGN</span> Reference Survey (CARS)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rothberg, Barry; Husemann, Bernd; Busch, Gerold; Dierkes, Jens; Eckart, Andreas; Krajnovic, Davor; Scharwaechter, Julia; Tremblay, Grant R.; Urrutia, Tanya</p> <p>2015-08-01</p> <p>We present the first science results from the Close <span class="hlt">AGN</span> Reference Survey (CARS). This program is a snapshot survey of 39 local type 1 <span class="hlt">AGN</span> (0.01 < z <0.06) designed to address the issue of <span class="hlt">AGN</span>-driven star formation quenching by characterizing the condition for star formation in <span class="hlt">AGN</span> host galaxies. The primary sample was observed with Multi Unit Spectrscopic Explorer (MUSE), an optical wavelength integral field unit (IFU) with a 1'x1' field of view on the VLT. The optical 3D spectroscopy complements existing sub-mm CO(1-0) data and near-IR imaging to establish a unique dataset combining molecular and stellar masses with star formation rates, gas, stellar kinematics and <span class="hlt">AGN</span> properties. The primary goals of CARS are to:1) investigate if the star formation efficiency and gas depletion time scales are suppressed as a consequence of <span class="hlt">AGN</span> feedback; 2) identify <span class="hlt">AGN</span>-driven outflows and their relation to the molecular gas reservoir of the host galaxy; 3) investigate the the balance of <span class="hlt">AGN</span> feeding and feedback through the ratio of the gas reservoir to the <span class="hlt">AGN</span> luminosity; and 4) provide the community with a reference survey of local <span class="hlt">AGN</span> with a high legacy value. Future work will incorporate near-infrared IFU observations to present a complete spatially resolved picture of the interplay among <span class="hlt">AGN</span>, star-formation, stellar populations, and the ISM.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017hsa9.conf..288O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017hsa9.conf..288O"><span>On the relation between X-ray absorption and optical extinction in <span class="hlt">AGN</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ordovás-Pascual, I.; Mateos, S.; Carrera, F. J.; Wiersema, K.; Caccianiga, A.; Della Ceca, R.; Severgnini, P.; Moretti, A.; Ballo, L.</p> <p>2017-03-01</p> <p>According to the Unified <span class="hlt">Model</span> of Active Galactic Nuclei (<span class="hlt">AGN</span>), an X-ray unabsorbed <span class="hlt">AGN</span> should appear as unobscured in the optical band (the so called type-1 <span class="hlt">AGN</span>). However, there is an important fraction (10–30%) of <span class="hlt">AGN</span> whose optical and X-ray classifications do not match. To provide insight into the origin of such apparent discrepancies, we have conducted two types of analysis: 1) a detailed study of the UV-to-near-IR emission of two X-ray low absorbed <span class="hlt">AGN</span> with high optical extinction drawn from the Bright Ultra-Hard XMM-Newton Survey (BUXS); 2) a statistical analysis of the optical obscuration and X-ray absorption properties of 159 type-1 <span class="hlt">AGN</span> drawn from BUXS to determine the distribution of dust-to-gas ratios in <span class="hlt">AGN</span> over a broad range of luminosities and redshifts. We have determined the impact of contamination from the <span class="hlt">AGN</span> hosts in their optical classification (detection or lack of detection of rest-frame UV-optical broad emission lines). This is an on-going project, but our preliminary results, reported below, are very promising.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AAS...22912103B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AAS...22912103B"><span>Hard X-ray Spectroscopy of Obscured <span class="hlt">AGN</span> with NuSTAR</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Balokovic, Mislav; Harrison, Fiona; NuSTAR Extragalactic Surveys Team</p> <p>2017-01-01</p> <p>The Nuclear Spectroscopic Telescope Array (NuSTAR) has enabled studies of the local active galactic nuclei (<span class="hlt">AGN</span>) to extend into the hard X-ray band, up to 79 keV, with unprecedented spatial resolution and sensitivity. As a part of its extragalactic program, NuSTAR is surveying the nearby population of <span class="hlt">AGN</span> detected at hard X-ray energies by the Swift Burst Alert Telescope (Swift/BAT), selecting even the most obscured local <span class="hlt">AGN</span>. I will highlight some of the results based on broadband X-ray spectroscopy of individual targets and present my work on the large representative sample of more than a hundred nearby obscured <span class="hlt">AGN</span>, which constitutes the largest available atlas of hard X-ray spectra of obscured <span class="hlt">AGN</span> to date. The high quality of the data allows us to probe the details of <span class="hlt">AGN</span> structures such as the X-ray-emitting corona and the toroidal obscurer in the under-explored spectral window above 10 keV. I will present both phenomenological results important for synthesis <span class="hlt">models</span> of the cosmic X-ray background, and a novel approach for constraining the geometry of the gas surrounding the supermassive black hole (including the accretion disk, the broad-line region, and the torus) from the hard X-ray band. Finally, I will discuss how what we learned from this survey of local <span class="hlt">AGN</span> relates to deeper high-redshift X-ray surveys and <span class="hlt">AGN</span> structure probes at other wavelengths.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015sofi.prop...48L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015sofi.prop...48L"><span><span class="hlt">AGN</span> Survey to characterize the clumpy torus using FORCAST</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lopez-Rodriguez, Enrique</p> <p>2015-10-01</p> <p>A geometrically and optically thick torus of gas and dust obscures the black hole and accretion disk in active galactic nuclei (<span class="hlt">AGN</span>) in some lines of sight. One of the most important question that still remain uncertain is: How do the properties, such as torus geometry and distribution of clumps, of the torus depend on the <span class="hlt">AGN</span> luminosity and/or activity class? Infrared (IR) observations are essential to these investigations as the torus intercepts and re-radiates (peaking within 30-40 um) a substantial amount of flux from the central engine. Near-IR (NIR) and mid-IR (MIR) observations from the ground have been key to advance our knowledge in this field. However, the atmosphere is opaque to the 30-40 um range and observations are impossible from ground-based telescopes. FORCAST presents a unique opportunity to explore <span class="hlt">AGN</span>, providing the best angular resolution observations within the 30-40 um range for the current suite of instruments. From our analysis using Cycle 2 observations, we found that FORCAST provides the largest constraining power of the clumpy torus <span class="hlt">models</span> in the suggested wavelength range. We therefore request an <span class="hlt">AGN</span> Survey using FORCAST of snapshot imaging observations of a flux-limited (>500 mJy at 37.1 um) sample of 23 Seyfert galaxies with existing high-angular resolution MIR spectra observed on 8-m class telescopes. Using the FORCAST data requested here in combination with already acquired NIR and MIR data, we will have an unprecedentedly homogeneous <span class="hlt">AGN</span> sample of IR (1-40 um) SED at the largest spatial-resolution, which yield to a better knowledge of the torus structure in the <span class="hlt">AGN</span> unified <span class="hlt">model</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015IAUGA..2225915R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015IAUGA..2225915R"><span>Impact of <span class="hlt">AGN</span> and stellar feedback on the gas of a simulated z~2 star-forming galaxy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Roos, Orianne; Bournaud, Frédéric; Juneau, Stephanie; Gabor, Jared</p> <p>2015-08-01</p> <p>With high-resolution simulations of star-forming disk galaxies at high redshift, we study the effects of combined <span class="hlt">AGN</span> and stellar feedback <span class="hlt">models</span> on the gas of the host-galaxy. <span class="hlt">AGN</span> feedback is <span class="hlt">modeled</span> using a standard thermal recipe of feedback (gas is heated and pushed away) plus a post-processing method to compute <span class="hlt">AGN</span> ionization. We first consider <span class="hlt">AGN</span> feedback only and show that, even though the <span class="hlt">AGN</span> generates powerful outflows, the effects of <span class="hlt">AGN</span> feedback on star formation is relatively weak on time-scales up to a few 100s of Myrs, even when long-range radiative feedback is accounted for. Furthermore, as the combination of stellar feedback <span class="hlt">models</span> generates outflows that are more powerful than the sum of the <span class="hlt">models</span> taken separately, we check whether combined <span class="hlt">AGN</span> and stellar feedback also couple non-linearly. We then include several stellar feedback sources on top of <span class="hlt">AGN</span> feedback, such as young stars creating HII regions through radiative pressure and supernovae releasing thermal and kinetic energy in the ISM. We follow their impact on the gas of high-resolution simulations and study the coupling between the different sources of outflows (<span class="hlt">AGN</span>, young stars, supernovae) , which could produce very fast outflows, with important outflow rates. How do these feedback-driven winds affect the host? What is the amount of expelled gas? What is its density and temperature and what is the consequence for in place and future star formation? Can such outflows change the distribution of existing stars?</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1982paph.conf....1P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1982paph.conf....1P"><span>SU(5) and New Departures in <span class="hlt">Unification</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pakvasa, S.; Tuan, S. F.</p> <p>1982-01-01</p> <p>"Just as today, most of us are certain of the validity of SU(2) × U(l) even though we have not seen a W or Z, so also if proton decay is seen at the expected rate, we can presume that <span class="hlt">unification</span> involves SU(S). Indeed, our faith in SU(2) × U(l) is not based entirely on hard experimental evidence. There is an infinite class of theories which give the same neutral current structure. But compared to SU(2) × U(l), the alternatives are complicated, unnatural and ugly. My faith in SU(5) is likewise based on my belief that the world is simple and beautiful." --Howard Georgi</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004JHEP...08..027C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004JHEP...08..027C"><span>Leptogenesis, neutrino masses and gauge <span class="hlt">unification</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cosme, N.</p> <p>2004-08-01</p> <p>Leptogenesis is considered in its natural context where Majorana neutrinos fit in a gauge <span class="hlt">unification</span> scheme and therefore couple to some extra gauge bosons. The masses of some of these gauge bosons are expected to be similar to those of the heavy Majorana particles, and this can have important consequences for leptogenesis. In fact, the effect can go both ways. Stricter bounds are obtained on one hand due to the dilution of the CP-violating effect by new decay and scattering channels, while, in a re-heating scheme, the presence of gauge couplings facilitates the re-population of the Majorana states. The latter effect allows in particular for smaller Dirac couplings.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1983AN....304..145T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1983AN....304..145T"><span>The problem of the Grand <span class="hlt">Unification</span> Theory</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Treder, H.-J.</p> <p></p> <p>The evolution and fundamental questions of physical theories unifying the gravitational, electromagnetic, and quantum-mechanical interactions are explored, taking Pauli's aphorism as a motto: 'Let no man join what God has cast asunder.' The contributions of Faraday and Riemann, Lorentz, Einstein, and others are discussed, and the criterion of Pauli is applied to Grand <span class="hlt">Unification</span> Theories (GUT) in general and to those seeking to link gravitation and electromagnetism in particular. Formal mathematical symmetry principles must be shown to have real physical relevance by predicting measurable phenomena not explainable without a GUT; these phenomena must be macroscopic because gravitational effects are to weak to be measured on the microscopic level. It is shown that empirical and theoretical studies of 'gravomagnetism', 'gravoelectricity', or possible links between gravoelectrity and the cosmic baryon assymmetry eventually lead back to basic questions which appear philosophical or purely mathematical but actually challenge physics to seek verifiable answers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004PhRvD..69c6003C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004PhRvD..69c6003C"><span>CP violation in weak interactions from orbifold reduction: Possible <span class="hlt">unification</span> structures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cosme, N.; Frère, J.-M.</p> <p>2004-02-01</p> <p>We present a mechanism to generate complex phases from real 4+1 dimensional couplings in a <span class="hlt">model</span> of weak interactions through dimensional reduction of a gauge theory. The orbifolding of a 4+1 dimensional Sp(4)×U(1) group is the minimal setup which provides both CP violation and an SU(2)×U(1) structure. We show that grand <span class="hlt">unification</span> requires at least SO(11).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002AGUFM.U61A0003T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002AGUFM.U61A0003T"><span>Computational <span class="hlt">Unification</span>: a Vision for Connecting Researchers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Troy, R. M.; Kingrey, O. J.</p> <p>2002-12-01</p> <p>Computational <span class="hlt">Unification</span> of science, once only a vision, is becoming a reality. This technology is based upon a scientifically defensible, general solution for Earth Science data management and processing. The computational <span class="hlt">unification</span> of science offers a real opportunity to foster inter and intra-discipline cooperation, and the end of 're-inventing the wheel'. As we move forward using computers as tools, it is past time to move from computationally isolating, "one-off" or discipline-specific solutions into a unified framework where research can be more easily shared, especially with researchers in other disciplines. The author will discuss how distributed meta-data, distributed processing and distributed data objects are structured to constitute a working interdisciplinary system, including how these resources lead to scientific defensibility through known lineage of all data products. Illustration of how scientific processes are encapsulated and executed illuminates how previously written processes and functions are integrated into the system efficiently and with minimal effort. Meta-data basics will illustrate how intricate relationships may easily be represented and used to good advantage. Retrieval techniques will be discussed including trade-offs of using meta-data versus embedded data, how the two may be integrated, and how simplifying assumptions may or may not help. This system is based upon the experience of the Sequoia 2000 and BigSur research projects at the University of California, Berkeley, whose goals were to find an alternative to the Hughes EOS-DIS system and is presently offered by Science Tools corporation, of which the author is a principal.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016agnw.confE..17J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016agnw.confE..17J"><span>Radio <span class="hlt">AGN</span> signatures in massive quiescent galaxies out to z=1.5</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Järvelä, Emilia</p> <p>2016-08-01</p> <p>Detection of gamma-rays from narrow-line Seyfert 1 galaxies (NLS1) by Fermi confirmed the presence of powerful relativistic jets in them, and thus challenged our understanding of active galactic nuclei (<span class="hlt">AGN</span>). In the current <span class="hlt">AGN</span> paradigm powerful relativistic jets are produced in massive elliptical galaxies with supermassive black holes. NLS1s differ from them significantly; they harbour lower mass black holes accreting at higher Eddington ratios, have preferably compact radio morphology, reside mostly in spiral galaxies, and were thought to be radio-quiet.Fermi's discovery invokes questions about the <span class="hlt">AGN</span> evolution; what triggers and maintains the <span class="hlt">AGN</span> activity, and what are the evolutionary lines of the different populations? It is also necessary to revise the <span class="hlt">AGN</span> <span class="hlt">unification</span> schemes to fit in NLS1s. They convolute the whole <span class="hlt">AGN</span> scenario, but offer us a new look on the jet phenomena and will help us construct a more comprehensive big picture of <span class="hlt">AGN</span>.Despite their importance, NLS1s are rather poorly studied as a class. For example, some NLS1s seem to be totally radio-silent, but a considerable fraction are radio-loud and thus probably host jets. This, along with other observational evidence, implies that they do not form a homogeneous class. However, it remains unclear what is triggering the radio loudness in some of them, but, for example, the properties of the host galaxy and the large-scale environment might play a role. Also the parent population of NLS1s remains an open question.We used various statistical methods, for example, multiwavelength correlations and principal component analysis to study a large sample of NLS1 sources. We will present the results and discuss the interplay between their properties, such as emission properties, black hole masses, large-scale environments, and their effect on radio loudness. We will also introduce the Metsähovi Radio Observatory NLS1 galaxy observing programme, which is the first one dedicated to systematical observations</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013A%26A...554A..85S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013A%26A...554A..85S"><span>Low-frequency radio observations of Seyfert galaxies: A test of the <span class="hlt">unification</span> scheme</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Singh, V.; Shastri, P.; Ishwara-Chandra, C. H.; Athreya, R.</p> <p>2013-06-01</p> <p>Aims: We present low-frequency radio imaging and spectral properties of a well-defined sample of Seyfert galaxies using GMRT 240/610 MHz dual frequency observations. Radio spectra of Seyfert galaxies over 240 MHz to 5.0 GHz are investigated using 240 MHz, 610 MHz flux densities derived from GMRT, and 1.4 GHz and 5.0 GHz flux densities mainly from published VLA data. We test the predictions of Seyfert <span class="hlt">unification</span> scheme by comparing the radio properties of Seyfert type 1s and type 2s. Methods: We chose a sample such that the two Seyferts subtypes have matched distributions in parameters that are independent of the orientation of <span class="hlt">AGN</span>, obscuring torus, and the host galaxy. Our sample selection criteria allowed us to assume that the two Seyfert subtypes are intrinsically similar within the framework of the <span class="hlt">unification</span> scheme. Results: The new observations at 240/610 MHz, together with archival observations at 1.4 GHz, 5.0 GHz show that types 1s and 2s have statistically similar radio luminosity distributions at 240 MHz, 610 MHz, 1.4 GHz, and 5.0 GHz. The spectral indices at selected frequency intervals (α240 MHz610 MHz, α610 MHz1.4 GHz, and α1.4 GHz5.0 GHz), as well as index measured over 240 MHz to 5.0 GHz (αint) for the two Seyfert subtypes, have similar distributions with median spectral index (α) ~ -0.7 (Sν ∝ να), consistent with the synchrotron emission from optically thin plasma. In our snapshot 240/610 MHz GMRT observations, most of the Seyfert galaxies primarily show an unresolved central radio component, except for a few sources in which faint kpc-scale extended emission is apparent at 610 MHz. Our results on the statistical comparison of the multifrequency radio properties of our sample Seyfert galaxies agree with the predictions of the Seyfert <span class="hlt">unification</span> scheme. Figures 2, 4 and Appendix A are available in electronic form at http://www.aanda.org</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016MNRAS.457..730P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MNRAS.457..730P"><span>Galaxy And Mass Assembly (GAMA): the 325 MHz radio luminosity function of <span class="hlt">AGN</span> and star-forming galaxies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Prescott, Matthew; Mauch, T.; Jarvis, M. J.; McAlpine, K.; Smith, D. J. B.; Fine, S.; Johnston, R.; Hardcastle, M. J.; Baldry, I. K.; Brough, S.; Brown, M. J. I.; Bremer, M. N.; Driver, S. P.; Hopkins, A. M.; Kelvin, L. S.; Loveday, J.; Norberg, P.; Obreschkow, D.; Sadler, E. M.</p> <p>2016-03-01</p> <p>Measurement of the evolution of both active galactic nuclei (<span class="hlt">AGN</span>) and star-formation in galaxies underpins our understanding of galaxy evolution over cosmic time. Radio continuum observations can provide key information on these two processes, in particular via the mechanical feedback produced by radio jets in <span class="hlt">AGN</span>, and via an unbiased dust-independent measurement of star formation rates. In this paper, we determine radio luminosity functions at 325 MHz for a sample of <span class="hlt">AGN</span> and star-forming galaxies by matching a 138 deg2 radio survey conducted with the Giant Metrewave Radio Telescope, with optical imaging and redshifts from the Galaxy And Mass Assembly survey. We find that the radio luminosity function at 325 MHz for star-forming galaxies closely follows that measured at 1.4 GHz. By fitting the <span class="hlt">AGN</span> radio luminosity function out to z = 0.5 as a double power law, and parametrizing the evolution as Φ ∝ (1 + z)k, we find evolution parameters of k = 0.92 ± 0.95 assuming pure density evolution and k = 2.13 ± 1.96 assuming pure luminosity evolution. We find that the Low Excitation Radio Galaxies are the dominant population in space density at lower luminosities. Comparing our 325 MHz observations with radio continuum imaging at 1.4 GHz, we determine separate radio luminosity functions for steep- and flat-spectrum <span class="hlt">AGN</span>, and show that the beamed population of flat-spectrum sources in our sample can be shifted in number density and luminosity to coincide with the unbeamed population of steep-spectrum sources, as is expected in the orientation-based <span class="hlt">unification</span> of <span class="hlt">AGN</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=terminology+AND+sciences+AND+translation&pg=3&id=EJ217980','ERIC'); return false;" href="http://eric.ed.gov/?q=terminology+AND+sciences+AND+translation&pg=3&id=EJ217980"><span>International Scientific Terminology and Neologisms in the Course of <span class="hlt">Unification</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Stoberski, Zygmunt</p> <p>1979-01-01</p> <p>Presents a glossary of scientific neologisms, compiled by the International Committee For <span class="hlt">Unification</span> of Terminological Neologisms. Entries are presented and defined in French, then glossed in various other languages. (AM)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014MNRAS.445.4155O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014MNRAS.445.4155O"><span>Extremely efficient Zevatron in rotating <span class="hlt">AGN</span> magnetospheres</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Osmanov, Z.; Mahajan, S.; Machabeli, G.; Chkheidze, N.</p> <p>2014-12-01</p> <p>A novel <span class="hlt">model</span> of particle acceleration in the magnetospheres of rotating active galactic nuclei (<span class="hlt">AGN</span>) is constructed. The particle energies may be boosted up to 1021 eV in a two-step mechanism: in the first stage, the Langmuir waves are centrifugally excited and amplified by means of a parametric process that efficiently pumps rotational energy to excite electrostatic fields. In the second stage, the electrostatic energy is transferred to particle kinetic energy via Landau damping made possible by rapid `Langmuir collapse'. The time-scale for parametric pumping of Langmuir waves turns out to be small compared to the kinematic time-scale, indicating high efficiency of the first process. The second process of `Langmuir collapse' - the creation of caverns or low-density regions - also happens rapidly for the characteristic parameters of the <span class="hlt">AGN</span> magnetosphere. The Langmuir collapse creates appropriate conditions for transferring electric energy to boost up already high particle energies to much higher values. It is further shown that various energy loss mechanism are relatively weak, and do not impose any significant constraints on maximum achievable energies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016agnw.confE..35G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016agnw.confE..35G"><span>Gamma-ray-selected <span class="hlt">AGN</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Giommi, Paolo</p> <p>2016-08-01</p> <p>The gamma-ray band is the most energetic part of the electromagnetic spectrum. As such it is also where selection effects are most severe, as it can only be reached by the most extreme non-thermal <span class="hlt">AGN</span>. Blazars, with their emission dominated by non-thermal blue-shifted radiation arising in a relativistic jet pointed in the direction of the observer, naturally satisfy this though requirement. For this reason, albeit these sources are intrisically very rare (orders of magnitude less abundant than radio quiet <span class="hlt">AGN</span> of the same optical magnitude) they almost completely dominate the extragalactic gamma-ray and very high energy sky. I will discuss the emission of different types of blazars and the selection effects that are at play in the gamma-ray band based on recent results from the current generation of gamma-ray astronomy satellites, ground-based Cherenkov telescopes, and Monte Carlo simulations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AAS...22325112C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AAS...22325112C"><span>The Importance of Winds for <span class="hlt">AGN</span> Feedback</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Crenshaw, D. M.; Kraemer, S. B.; Schmitt, H. R.; Fischer, T. C.; Gagne, J.</p> <p>2014-01-01</p> <p>Active galactic nuclei (<span class="hlt">AGN</span>) are fed by accretion of matter onto supermassive black holes (SMBHs), generating huge amounts of radiation from very small volumes. <span class="hlt">AGN</span> also provide feedback to their environments via mass outflows of ionized gas, which could play a critical role in the formation of large-scale structure in the early Universe, chemical enrichment of the intergalactic medium, and self-regulation of SMBH and galactic bulge growth. We provide an update on our research on the winds in nearby moderate-luminosity <span class="hlt">AGN</span>, In particular, we concentrate on winds that occur on relatively large scales (hundreds of parsecs) that are revealed through spatially resolved HST spectra of emission-line gas in the narrow line regions (NLRs) of nearby <span class="hlt">AGN</span>. We discuss the techniques for measuring the mass outflow rates and kinetic luminosities of these <span class="hlt">AGN</span> winds and gauge their importance for providing significant <span class="hlt">AGN</span> feedback.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011JHEP...05..132J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JHEP...05..132J"><span>RG invariants, <span class="hlt">unification</span> and the role of the messenger scale in General Gauge Mediation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jaeckel, Joerg; Khoze, Valentin V.; Wymant, Chris</p> <p>2011-05-01</p> <p>In General Gauge Mediation (GGM) all MSSM soft sfermion masses at a high scale Mmess can be parameterised by three a priori independent scales Λ S; 1,2,3( M mess). (Similarly the gaugino masses are given by Λ G; 1,2,3( M mess).) For the first two generations this parameterisation in terms of a set of running Λ S; 1,2,3( μ) — conveniently obtained from appropriate RG invariants — continues to hold all the way down to the electroweak scale. This is not the case for the third generation because of the large Yukawa couplings. Together these two observations imply that the messenger scale is an additional parameter of GGM <span class="hlt">models</span>. In <span class="hlt">models</span> where all messengers are in complete GUT multiplets (without significant mass splittings), all Λ S, r are equal at M mess. Starting from the observable mass spectrum at the electroweak scale we present a strategy to determine if this <span class="hlt">unification</span> occurs and at which scale. This approach uses data accessible at colliders to gain insight into high scale <span class="hlt">unification</span> physics beyond the <span class="hlt">unification</span> of gauge couplings.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JHEP...08..089A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JHEP...08..089A"><span>LHC phenomenology of natural MSSM with non-universal gaugino masses at the <span class="hlt">unification</span> scale</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Abe, Hiroyuki; Kawamura, Junichiro; Omura, Yuji</p> <p>2015-08-01</p> <p>In this letter, we study collider phenomenology in the supersymmetric Standard <span class="hlt">Model</span> with a certain type of non-universal gaugino masses at the gauge coupling <span class="hlt">unification</span> scale, motivated by the little hierarchy problem. In this scenario, especially the wino mass is relatively large compared to the gluino mass at the <span class="hlt">unification</span> scale, and the heavy wino can relax the fine-tuning of the higgsino mass parameter, so-called μ-parameter. Besides, it will enhance the lightest Higgs boson mass due to the relatively large left-right mixing of top squarks through the renormalization group (RG) effect. Then 125 GeV Higgs boson could be accomplished, even if the top squarks are lighter than 1 TeV and the μ parameter is within a few hundreds GeV. The right-handed top squark tends to be lighter than the other sfermions due to the RG runnings, then we focus on the top squark search at the LHC. Since the top squark is almost right-handed and the higgsinos are nearly degenerate, 2 b + E T miss channel is the most sensitive to this scenario. We figure out current and expected experimental bounds on the lightest top squark mass and <span class="hlt">model</span> parameters at the gauge coupling <span class="hlt">unification</span> scale.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ebha.confE..30F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ebha.confE..30F"><span>Fast Ionized X-ray Absorbers in <span class="hlt">AGNs</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fukumura, K.; Tombesi, F.; Kazanas, D.; Shrader, C.; Behar, E.; Contopoulos, I.</p> <p>2015-07-01</p> <p>We present a study of X-ray ionization of MHD accretion-disk wind <span class="hlt">models</span> in an effort to explain the highly-ionized ultra-fast outflows (UFOs) identified as X-ray absorbers recently detected in various sub-classes of Seyfert <span class="hlt">AGNs</span>. Our primary focus is to show that magnetically-driven outflows are physically plausible candidates to account for the <span class="hlt">AGN</span> X-ray spectroscopic observations. We calculate its X-ray ionization and the ensuing X-ray absorption line spectra in comparison with an XXM-Newton/EPIC spectrum of the narrow-line Seyfert <span class="hlt">AGN</span>, PG 1211+143. We find, through identifying the detected features with Fe Kα transitions, that the absorber has a characteristic ionization parameter of log(xi[erg cm/s]) = 5-6 and a hydrogen-equivalent column density on the order of 1e23 cm-2, outflowing at a sub-relativistic velocity of v/c = 0.1-0.2. The best-fit <span class="hlt">model</span> favors its radial location at R = 200 Rs (Rs is the Schwarzschild radius), with a disk inner truncation radius at Rt = 30Rs. The overall K-shell feature in data is suggested to be dominated by Fe XXV with very little contribution from Fe XXVI and weakly-ionized iron, which is in a good agreement with a series of earlier analysis of the UFOs in various <span class="hlt">AGNs</span> including PG 1211+143.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016HEAD...1510003L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016HEAD...1510003L"><span>New insights into <span class="hlt">AGN</span> coronae</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lohfink, Anne; Fabian, Andrew C.; Malzac, Julien; Belmont, Renaud; Buisson, Douglas</p> <p>2016-04-01</p> <p>Active galactic nuclei (<span class="hlt">AGN</span>) are some of the most energetic sources of radiation in the Universe. The conversion of gravitational energy into radiation is thought to take place in an accretion disk/corona system just outside the black hole. In this system thermal, UV/optical photons from the accretion disk are upscattered in a corona of hot electrons situated above the accretion disk producing X-rays. The nature of this Comptonizing corona remains a key open question in <span class="hlt">AGN</span> physics. The NuSTAR satellite provides the opportunity to study the Comptonization spectrum produced by the corona in great detail. In our talk we will show some key results from these new studies of the Comptonization spectrum. We explore how, together with our growing knowledge of coronal sizes, we are able to draw first conclusions about the physics taking place in the corona. We find evidence for coronae to be hot and radiatively compact, putting them close to the boundary of the region in the compactness-temperature diagram which is forbidden due to runaway pair production. This suggests that pair production and annihilation are essential ingredients in the coronae of <span class="hlt">AGN</span> and that they control the coronal temperature and shape of the observed spectra.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AAS...21922506B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AAS...21922506B"><span>Detecting Dual <span class="hlt">AGN</span> at High Redshift</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barrows, Robert S.</p> <p>2012-01-01</p> <p>The existence of supermassive black holes (SMBHs) in most, if not all, galaxies, along with observations of galaxy mergers, suggests that pairs of SMBHs should exist for some time in the merger remnant. Observational evidence for these systems at kpc-scale separations (i.e. dual <span class="hlt">AGN</span>) has dramatically increased recently through a combination of spectral and morphological selections. I discuss observations of CXOXBJ142607.6+353351 (CXOJ1426+35), a candidate dual <span class="hlt">AGN</span> at z=1.175, and put its properties, including significant obscuration, within the context of other candidate/confirmed dual <span class="hlt">AGN</span> at lower redshifts. Though dual <span class="hlt">AGN</span> are expected to be more common at higher redshifts, they are more difficult to detect. Furthermore, adding to the difficulties of detection are a number of other physical mechanisms which can mimic the spectroscopic signature of two Type 2 <span class="hlt">AGN</span>. In particular, I will discuss the possibility of strong outflows from an <span class="hlt">AGN</span>. These outflow phenomena can be an important feedback mechanism in galaxies and are apparently common in <span class="hlt">AGN</span>, making them a viable alternative to the dual <span class="hlt">AGN</span> scenario. Based on our candidate's luminosity and emission line intensities, we find that an outflow is a possibility. If this is the case, such an outflow would be especially strong and has implications for <span class="hlt">AGN</span> feedback in galaxies. However, the dual <span class="hlt">AGN</span> scenario cannot be ruled out, and at z=1.175, the two putative <span class="hlt">AGN</span> could potentially be resolved with Chandra. Other candidate dual <span class="hlt">AGN</span> at similar redshifts and with significant obscuration could also be confirmed this way. This research was sponsored by the Strategic University Research Partnership Program, the National Aeronautics and Space Administration and the Arkansas NASA EPSCoR program.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AAS...22942901W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AAS...22942901W"><span><span class="hlt">AGN</span> feedback in action? - outflows and star formation in type 2 <span class="hlt">AGNs</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Woo, Jong-Hak</p> <p>2017-01-01</p> <p>We present the statistical constraints on the ionized gas outflows and their connection to star formation, using a large sample of ~110,000 <span class="hlt">AGNs</span> and star-forming galaxies at z < 0.3. First, we find a dramatic difference of the outflow signatures between <span class="hlt">AGNs</span> and star-forming galaxies based on the [OIII] emission line kinematics. While the [OIII] velocity and velocity dispersion of star forming galaxies can be entirely accounted by the gravitational potential of host galaxies, <span class="hlt">AGNs</span> clearly show non-gravitational kinematics, which is comparable to or stronger than the virial motion caused by the gravitational potential. Second, the distribution in the [OIII] velocity - velocity dispersion diagram dramatically expands toward large values with increasing <span class="hlt">AGN</span> luminosity, implying that the outflows are <span class="hlt">AGN</span>-driven. Third, the fraction of <span class="hlt">AGNs</span> with a signature of outflow kinematics, steeply increases with <span class="hlt">AGN</span> luminosity and Eddington ratio. In particular, the majority of luminous <span class="hlt">AGNs</span> presents strong non-gravitational kinematics in the [OIII] profile. Interestingly, we find that the specific star formation of non-outflow <span class="hlt">AGNs</span> is much lower than that of strong outflow <span class="hlt">AGNs</span>, while the star formation rate of strong outflow <span class="hlt">AGNs</span> is comparable to that of star forming galaxies. We interpret this trend as a delayed <span class="hlt">AGN</span> feedback as it takes dynamical time for the outflows to suppress star formation in galactic scales.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JHEP...04..120I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JHEP...04..120I"><span>Exact SU(5) Yukawa matrix <span class="hlt">unification</span> in the general flavour violating MSSM</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Iskrzyński, Mateusz; Kowalska, Kamila</p> <p>2015-04-01</p> <p>We investigate the possibility of satisfying the SU(5) boundary condition Y d = Y eT at the GUT scale within the renormalizable R-parity conserving Minimal Supersymmetric Standard <span class="hlt">Model</span> (MSSM). Working in the super-CKM basis, we consider non-zero flavour off-diagonal entries in the soft SUSY-breaking mass matrices and the A-terms. At the same time, the diagonal A-terms are assumed to be suppressed by the respective Yukawa couplings. We show that a non-trivial flavour structure of the soft SUSY-breaking sector can contribute to achieving precise Yukawa coupling <span class="hlt">unification</span> for all three families, and that the relevant flavour-violating parameters are , , and A {12/21/ d }. We indicate the parameter space regions where the Yukawa <span class="hlt">unification</span> condition can be satisfied, and we demonstrate that it is consistent with a wide set of experimental constraints, including flavour and electroweak observables, Higgs physics and the LHC bounds. However, as a consequence of the down-electron Yukawa <span class="hlt">unification</span> requirement, the MSSM vacuum in our scenario is metastable, though long-lived. We also point out that the lightest neutralino needs to be almost purely bino-like and relatively light, with the mass in the ballpark of 250 GeV. Since the proper value of the dark matter relic density is in this case obtained through co-annihilation with a sneutrino, at least one generation of sleptons must be light. Such a clear experimental prediction makes the flavour-violating SU(5) Yukawa <span class="hlt">unification</span> scenario fully testable at the LHC TeV with the 3-lepton searches for electroweakino production.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016IJMPA..3150102L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016IJMPA..3150102L"><span>SU(2/1) gauge-Higgs <span class="hlt">unification</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Loginov, E. K.</p> <p>2016-06-01</p> <p>We discuss a question whether the observed Weinberg angle and Higgs mass are calculable in the formalism based on a construction in which the electroweak gauge group SU(2) × U(1)Y is embedded in the graded Lie group SU(2/1). Here, we follow original works of Ne’eman and Fairlie believing that bosonic fields take their values in the Lie superalgebra and fermionic fields take their values in its representation space. At the same time, our approach differs significantly. The main one is that while for them the gauge symmetry group is SU(2/1), here we consider only symmetries generated by its even subgroup, i.e. symmetries of the standard electroweak <span class="hlt">model</span>. The reason is that such formalism fixes the quartic Higgs coupling and at the same time removes the sign and statistics problems. The main result is that the presented <span class="hlt">model</span> predicts values of the Weinberg angle and the Higgs mass correctly up to the two-loop level. Moreover, the <span class="hlt">model</span> sets the <span class="hlt">unification</span> scale coinciding with the electroweak scale and automatically describes the fermions correctly with the correct quark and lepton charges.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21325410','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21325410"><span>Dark matter as the signal of grand <span class="hlt">unification</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kadastik, Mario; Kannike, Kristjan; Raidal, Martti</p> <p>2009-10-15</p> <p>We argue that the existence of dark matter (DM) is a possible consequence of grand <span class="hlt">unification</span> (GUT) symmetry breaking. In GUTs like SO(10), discrete Z{sub 2} matter parity (-1){sup 3(B-L)} survives despite broken B-L, and group theory uniquely determines that the only possible Z{sub 2}-odd matter multiplets belong to representation 16. We construct the minimal nonsupersymmetric SO(10) <span class="hlt">model</span> containing one scalar 16 for DM and study its predictions below M{sub G}. We find that electroweak symmetry breaking occurs radiatively due to DM couplings to the standard <span class="hlt">model</span> Higgs boson. For thermal relic DM the mass range M{sub DM}{approx}O(0.1-1) TeV is predicted by <span class="hlt">model</span> perturbativity up to M{sub G}. For M{sub DM}{approx}O(1) TeV to explain the observed cosmic ray anomalies with DM decays, there exists a lower bound on the spin-independent direct detection cross section within the reach of planned experiments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010IAUS..267..402M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010IAUS..267..402M"><span>Feedback from <span class="hlt">AGN</span>: The Kinetic/Radio Luminosity Function</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Melini, Gabriele; La Franca, Fabio; Fiore, Fabrizio</p> <p>2010-05-01</p> <p>We have measured the probability distribution function of the ratio RX = log L1.4/LX, where L1.4/LX = ν Lν(1.4 GHz)/LX(2-10 keV), between the 1.4 GHz and the unabsorbed 2-10 keV luminosities and its dependence on LX and z. We have used a complete sample of ~1800 hard X-ray selected <span class="hlt">AGN</span>, observed in the 1.4 GHz band, cross-correlated in order to exclude FR II-type objects, and thus obtain a contemporaneous measure of the radio and X-ray emission. The distribution P(RX|LX,z) is shown in Figure 1. Convolution of the distribution P(RX|LX,z) with the 2-10 keV X-ray <span class="hlt">AGN</span> luminosity function from La Franca et al. (2005) and the relations between radio power and kinetic energy from Best et al. (2006) and Willott et al. (1999) allows us to derive the <span class="hlt">AGN</span> kinetic power and its evolution. As shown in Figure 1, our results are in good agreement with the predictions of the most recent <span class="hlt">models</span> of galaxy formation and evolution (e.g., Croton et al. 2006), where <span class="hlt">AGN</span> radio feedback is required to quench the star formation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AN....337..454F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AN....337..454F"><span>Fast ionized X-ray absorbers in <span class="hlt">AGNs</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fukumura, K.; Tombesi, F.; Kazanas, D.; Shrader, C.; Behar, E.; Contopoulos, I.</p> <p>2016-05-01</p> <p>We investigate the physics of the X-ray ionized absorbers often identified as warm absorbers (WAs) and ultra-fast outflows (UFOs) in Seyfert <span class="hlt">AGNs</span> from spectroscopic studies in the context of magnetically-driven accretion-disk wind scenario. Launched and accelerated by the action of a global magnetic field anchored to an underlying accretion disk around a black hole, outflowing plasma is irradiated and ionized by an <span class="hlt">AGN</span> radiation field characterized by its spectral energy density (SED). By numerically solving the Grad-Shafranov equation in the magnetohydrodynamic (MHD) framework, the physical property of the magnetized disk-wind is determined by a wind parameter set, which is then incorporated into radiative transfer calculations with xstar photoionization code under heating-cooling equilibrium state to compute the absorber's properties such as column density N_H, line-of-sight (LoS) velocity v, ionization parameter ξ, among others. Assuming that the wind density scales as n ∝ r-1, we calculate theoretical absorption measure distribution (AMD) for various ions seen in <span class="hlt">AGNs</span> as well as line spectra especially for the Fe Kα absorption feature by focusing on a bright quasar PG 1211+143 as a case study and show the <span class="hlt">model</span>'s plausibility. In this note we demonstrate that the proposed MHD-driven disk-wind scenario is not only consistent with the observed X-ray data, but also help better constrain the underlying nature of the <span class="hlt">AGN</span> environment in a close proximity to a central engine.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016MNRAS.460.2979V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MNRAS.460.2979V"><span>The cosmic evolution of massive black holes in the Horizon-<span class="hlt">AGN</span> simulation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Volonteri, M.; Dubois, Y.; Pichon, C.; Devriendt, J.</p> <p>2016-08-01</p> <p>We analyse the demographics of black holes (BHs) in the large-volume cosmological hydrodynamical simulation Horizon-<span class="hlt">AGN</span>. This simulation statistically <span class="hlt">models</span> how much gas is accreted on to BHs, traces the energy deposited into their environment and, consequently, the back-reaction of the ambient medium on BH growth. The synthetic BHs reproduce a variety of observational constraints such as the redshift evolution of the BH mass density and the mass function. Strong self-regulation via <span class="hlt">AGN</span> feedback, weak supernova feedback, and unresolved internal processes result in a tight BH-galaxy mass correlation. Starting at z ˜ 2, tidal stripping creates a small population of BHs over-massive with respect to the halo. The fraction of galaxies hosting a central BH or an <span class="hlt">AGN</span> increases with stellar mass. The <span class="hlt">AGN</span> fraction agrees better with multi-wavelength studies, than single-wavelength ones, unless obscuration is taken into account. The most massive haloes present BH multiplicity, with additional BHs gained by ongoing or past mergers. In some cases, both a central and an off-centre <span class="hlt">AGN</span> shine concurrently, producing a dual <span class="hlt">AGN</span>. This dual <span class="hlt">AGN</span> population dwindles with decreasing redshift, as found in observations. Specific accretion rate and Eddington ratio distributions are in good agreement with observational estimates. The BH population is dominated in turn by fast, slow, and very slow accretors, with transitions occurring at z = 3 and z = 2, respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015IAUGA..2268103B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015IAUGA..2268103B"><span>Towards an understanding of the Radio-mode <span class="hlt">AGN</span> Feedback at higher redshifts</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bîrzan, Laura</p> <p>2015-08-01</p> <p>Direct evidence for feedback by active galactic nuclei (<span class="hlt">AGN</span>) on the intra-cluster medium (ICM) of nearby groups and clusters has been provided by Chandra X-ray images. They show that the radio lobes emitted by the <span class="hlt">AGN</span> create cavities in the hot cluster atmosphere, whichaffects the cooling gas that leads to star formation and galaxy growth and allow a direct measurement of the bulk of the <span class="hlt">AGN</span>'s power. Consequently, <span class="hlt">AGN</span> feedback is now recognized as a necessary ingredient for galaxy formation <span class="hlt">models</span> to prevent overcooling in massive halos. It is therefore important to study <span class="hlt">AGN</span> feedback at redshifts where clusters are known to form (z ~ 1) and <span class="hlt">AGN</span> feedback is predicted to regulate star formation in the most massive galaxies. Together with radio data, the cavities allow us to derive scaling relations that can be used to estimate the <span class="hlt">AGN</span> feedback power using only radio data. I will review the importance of such relations for extending current studies of feedback with new and upcoming radio telescopes such as LOFAR and SKA, and I will present preliminary results from deep low-frequency LOFAR observations of the NEP field to understand if the local cooling-to-heating balance and the corresponding scaling relations (between jet power and radio luminosity) hold at these redshifts (z > 0.5).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12754432','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12754432"><span>[World microbiological <span class="hlt">unification</span> according to Woodrow Borah].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sabbatani, Sergio</p> <p>2002-12-01</p> <p>Now that developments in communication media are turning the world into a "global village" and there are risks of global epidemics due to infectious agents spread by possible terrorist attacks, this article aims to remind us of what happened in the "New World", where in the space of a few decades the indigenous civilizations disappeared. When, following the geographical discoveries of the 15th, 16th and 17th centuries, millions of people met European sailors, soldiers and traders, the outbreak of pathocenosis was destructive--the intensity of this effect was directly related to the degree of isolation of the indigenous populations colonised by the Europeans. The author of this article recalls the Woodrow Borah thesis. Borah, a former History Professor at Berkeley University, elaborated a theory according to which the microbiological <span class="hlt">unification</span> of the world is the prime cause of the genocide of the indigenous population in America and Oceania. The author emphasises that the events following the discovery of the American continent are very similar to the plague epidemic which started in 1348 in Europe.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PTEP.2016i3B01F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PTEP.2016i3B01F"><span>Toward realistic gauge-Higgs grand <span class="hlt">unification</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Furui, Atsushi; Hosotani, Yutaka; Yamatsu, Naoki</p> <p>2016-09-01</p> <p>The SO(11) gauge-Higgs grand <span class="hlt">unification</span> in the Randall-Sundrum warped space is presented. The 4D Higgs field is identified as the zero mode of the fifth-dimensional component of the gauge potentials, or as the fluctuation mode of the Aharonov-Bohm phase θ along the fifth dimension. Fermions are introduced in the bulk in the spinor and vector representations of SO(11). SO(11) is broken to SO(4)×SO(6) by the orbifold boundary conditions, which is broken to SU2×U1×SU3 by a brane scalar. Evaluating the effective potential V(θ), we show that the electroweak symmetry is dynamically broken to U1. The quark-lepton masses are generated by the Hosotani mechanism and brane interactions, with which the observed mass spectrum is reproduced. Proton decay is forbidden thanks to the new fermion number conservation. It is pointed out that there appear light exotic fermions. The Higgs boson mass is determined with the quark-lepton masses given; however, it turns out to be smaller than the observed value.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/58051','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/58051"><span>Yukawa <span class="hlt">unification</span>: The good, the bad, and the ugly</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Rattazzi, R.; Sarid, U.; Hall, L.J.</p> <p>1993-05-01</p> <p>We analyze some consequences of grand <span class="hlt">unification</span> of the third-generation Yukawa couplings, in the context of the minimal supersymmetric standard <span class="hlt">model</span>. We address two issues: the prediction of the top quark mass, and the generation of the top-bottom mass hierarchy through a hierarchy of Higgs vacuum expectation values. The top mass is strongly dependent on a certain ratio of superpartner masses. And the VEV hierarchy always entails some tuning of the GUT-scale parameters. We study the RG equations and their semi-analytic solutions, which exhibit several interesting features, such as a focusing effect for a large Yukawa coupling in the limit of certain symmetries and a correlation between the A terms (which contribute to b {yields} s{gamma}) and the gaugino masses. This study shows that non-universal soft-SUSY-breaking masses are favored (in particular for splitting the Higgs-doublets via D-terms and for allowing more natural scenarios of symmetry breaking), and hints at features desired in Yukawa-unified <span class="hlt">models</span>. Several phenomenological implications are also revealed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009JHEP...08..002T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009JHEP...08..002T"><span>Probing Yukawa <span class="hlt">unification</span> with K and B mixing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Trine, Stéphanie; Westhoff, Susanne; Wiesenfeldt, Sören</p> <p>2009-08-01</p> <p>We consider corrections to the <span class="hlt">unification</span> of down-quark and charged-lepton Yukawa couplings in supersymmetric GUTs, which links the large ντ-νμ mixing angle to b → s transitions. These corrections generically occur in simple grand-unified <span class="hlt">models</span> with small Higgs representations and affect s → d and b → d transitions via the mixing of the corresponding right-handed superpartners. On the basis of a specific SUSY-SO(10) <span class="hlt">model</span>, we analyze the constraints from K-bar K and Bd-bar Bd mixing on the additional tilde dR-tilde sR rotation angle θ. We find that epsilonK already sets a stringent bound on θ, θmax ~ Script O(1°), indicating a very specific flavor structure of the correction operators. The impact of the large neutrino mixings on the unitarity triangle analysis is also briefly discussed, as well as their ability to account for the sizeable CP-violating phase observed recently in Bs → J/ψphi decays.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1023783','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1023783"><span><span class="hlt">AGN</span> Clustering in the Local Universe: An Unbiased Picture from Swift-BAT</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Cappelluti, N.; Ajello, M.; Burlon, D.; Krumpe, M.; Miyaji, T.; Bonoli, S.; Greiner, J.; /Garching, Max Planck Inst., MPE</p> <p>2011-08-11</p> <p>We present the clustering measurement of hard X-ray selected <span class="hlt">AGN</span> in the local Universe. We used a sample of 199 sources spectroscopically confirmed detected by Swift-BAT in its 15-55 keV all-sky survey. We measured the real space projected auto-correlation function and detected a signal significant on projected scales lower than 200 Mpc/h. We measured a correlation length of r{sub 0} = 5.56{sup +0.49}{sub -0.43} Mpc/h and a slope {gamma} = 1.64{sup -0.08}{sub -0.07}. We also measured the auto-correlation function of Tyep I and Type II <span class="hlt">AGN</span> and found higher correlation length for Type I <span class="hlt">AGN</span>. We have a marginal evidence of luminosity dependent clustering of <span class="hlt">AGN</span>, as we detected a larger correlation length of luminous <span class="hlt">AGN</span> than that of low luminosity sources. The corresponding typical host DM halo masses of Swift-BAT are {approx} log(M{sub DMH) {approx} 12-14 h{sup -1}M/M{sub {circle_dot}} which is the typical mass of a galaxy group. We estimated that the local <span class="hlt">AGN</span> population has a typical lifetime {tau}{sub <span class="hlt">AGN</span>} {approx}0.7 Gyr, it is powered by SMBH with mass M{sub BH} {approx}1-10x10{sup 8} M{sub {circle_dot}} and accreting with very low efficiency, log({epsilon}){approx}-2.0>. We also conclude that local <span class="hlt">AGN</span> galaxies are typically red-massive galaxies with stellar mass of the order 2-80x10{sup 10} h{sup -1}M{sub {circle_dot}}. We compared our results with clustering predictions of merger-driven <span class="hlt">AGN</span> triggering <span class="hlt">models</span> and found a good agreement.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhDT.......104S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhDT.......104S"><span>A radio view of high-energy emitting <span class="hlt">AGNs</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schulz, Robert Frank</p> <p>2016-07-01</p> <p>Active galactic nuclei (<span class="hlt">AGNs</span>) are among the most energetic objects in the Universe. These galaxies that are dominated in part or even throughout the electromagnetic spectrum by emission from their central, compact region. <span class="hlt">AGNs</span> are extensively studied by multi-wavelength observations. In the standard picture, the main driver of an <span class="hlt">AGN</span> is a supermassive black hole (SMBH) in its centre that is surrounded by an accretion disk. Perpendicular to the disk, in the vicinity of highly magnetized SMBH relativistic outflows of plasma, so-called jets, can form on either side that can reach far beyond the host galaxy. Only about 10% of all <span class="hlt">AGNs</span> are dominated by emission from these jets due to relativistic beaming effects and these so-called blazars dominate the extragalactic gamma-ray sky. It is commonly accepted that the low-energy emission (radio to UV/X-ray) is due to synchrotron emission from the jet. The high-energy emission is considered to stem from inverse-Compton scattering of photons on the jet particles, but different sources for these photons are discussed (internal or external to the <span class="hlt">AGN</span>) and other <span class="hlt">models</span> for the high-energy emission have also been proposed. The nature of the high-energy emission is strongly linked to the location of the emission region in the jet which requires a detailed understanding of the formation and evolution of jets. Radio observations especially using very long baseline interferometry (VLBI) provide the best way to gain direct information on the intrinsic properties of jets down to sub-pc scales, close to their formation region. In this thesis, I focus on the properties of three different <span class="hlt">AGNs</span>, IC 310, PKS2004-447, and 3C 111 that belong to the small non-blazar population of gamma-ray-loud <span class="hlt">AGNs</span>. I study them in detail with a variety of radio astronomical instruments with respect to their high-energy emission and in the context of the large monitoring programmes MOJAVE (Monitoring Of Jets in Active galactic nuclei with VLBA Experiments) and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015IAUGA..2257581B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015IAUGA..2257581B"><span>Results from the NuSTAR Survey of Swift/BAT <span class="hlt">AGN</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Balokovic, Mislav; Harrison, Fiona</p> <p>2015-08-01</p> <p>The Nuclear Spectroscopic Telescope Array (NuSTAR) has enabled studies of the local active galactic nuclei (<span class="hlt">AGN</span>) to extend into the spectral window above 10 keV with unprecedented spatial resolution and two orders of magnitude better sensitivity than any other instrument operating in that energy range. As a part of its long-term extragalactic program NuSTAR is surveying the nearby population of <span class="hlt">AGN</span> detected at hard X-ray energies by the Swift Burst Alert Telescope (Swift/BAT). We present results based on 15-25 ks observations of ~150 Swift/BAT <span class="hlt">AGN</span> surveyed in the first 2.5 years of NuSTAR operation. This sample forms an atlas of the highest quality hard X-ray spectra available to date for a large number of <span class="hlt">AGN</span>. Assuming a range of hard X-ray spectral <span class="hlt">models</span>, phenomenological as well as physically motivated, we constrain the main spectral parameters for each source individually and test the applicability of the <span class="hlt">models</span> on a large sample for the first time. This analysis allows us to determine distributions of the main spectral parameters (spectral index, high-energy cut-off, absorption column, reflection strength, iron line equivalent width) in a well-defined population of nearby <span class="hlt">AGN</span>. We find that approximately 70% of obscured <span class="hlt">AGN</span> spectra can be well <span class="hlt">modeled</span> in terms of simple <span class="hlt">models</span> used in the literature, while the rest requires careful consideration of more advanced <span class="hlt">models</span>. We will discuss the implications for the local <span class="hlt">AGN</span> population, the effects on interpretation of high-redshift <span class="hlt">AGN</span> observations, and the limitations of the current results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080039128','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080039128"><span>SWIFT BAT Survey of <span class="hlt">AGN</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tueller, J.; Mushotzky, R. F.; Barthelmy, S.; Cannizzo, J. K.; Gehrels, N.; Markwardt, C. B.; Skinner, G. K.; Winter, L. M.</p> <p>2008-01-01</p> <p>We present the results1 of the analysis of the first 9 months of data of the Swift BAT survey of <span class="hlt">AGN</span> in the 14-195 keV band. Using archival X-ray data or follow-up Swift XRT observations, we have identified 129 (103 <span class="hlt">AGN</span>) of 130 objects detected at [b] > 15deg and with significance > 4.8-delta. One source remains unidentified. These same X-ray data have allowed measurement of the X-ray properties of the objects. We fit a power law to the logN - log S distribution, and find the slope to be 1.42+/-0.14. Characterizing the differential luminosity function data as a broken power law, we find a break luminosity logL*(ergs/s)= 43.85+/-0.26. We obtain a mean photon index 1.98 in the 14-195 keV band, with an rms spread of 0.27. Integration of our luminosity function gives a local volume density of <span class="hlt">AGN</span> above 10(exp 41) erg/s of 2.4x10(exp -3) Mpc(sup -3), which is about 10% of the total luminous local galaxy density above M* = -19.75. We have obtained X-ray spectra from the literature and from Swift XRT follow-up observations. These show that the distribution of log nH is essentially flat from nH = 10(exp 20)/sq cm to 10(exp 24)/sq cm, with 50% of the objects having column densities of less than 10(exp 22)/sq cm. BAT Seyfert galaxies have a median redshift of 0.03, a maximum log luminosity of 45.1, and approximately half have log nH > 22.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004ASPC..311...37W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004ASPC..311...37W"><span>Spectral Energy Distributions of Quasars and <span class="hlt">AGN</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wilkes, B.</p> <p>2004-06-01</p> <p>Active Galactic Nuclei (<span class="hlt">AGN</span>) are multiwavelength emitters. To have any hope of understanding them, or even to determine their energy output, we must observe them in multiple wavebands using many telescopes. I will review what we have learned from broad-band observations of relatively bright, low-redshift <span class="hlt">AGN</span> over the past ˜ 15 years. <span class="hlt">AGN</span> can be found at all wavelengths but each provides a different view of the intrinsic population, often with little overlap between samples selected in different wavebands. I look forward to the full view of the intrinsic population which we will obtain over the next few years with surveys using today's new, sensitive observatories. These surveys are already finding enough new and different <span class="hlt">AGN</span> candidates to pose the question ``What IS an <span class="hlt">AGN</span>?".</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AAS...22741903D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AAS...22741903D"><span>The Swift <span class="hlt">AGN</span> and Cluster Survey</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Danae Griffin, Rhiannon; Dai, Xinyu; Kochanek, Christopher S.; Bregman, Joel N.; Nugent, Jenna</p> <p>2016-01-01</p> <p>The Swift active galactic nucleus (<span class="hlt">AGN</span>) and Cluster Survey (SACS) uses 125 deg^2 of Swift X-ray Telescope serendipitous fields with variable depths surrounding X-ray bursts to provide a medium depth (4 × 10^-15 erg cm^-2 s^-1) and area survey filling the gap between deep, narrow Chandra/XMM-Newton surveys and wide, shallow ROSAT surveys. Here, we present the first two papers in a series of publications for SACS. In the first paper, we introduce our method and catalog of 22,563 point sources and 442 extended sources. We examine the number counts of the <span class="hlt">AGN</span> and galaxy cluster populations. SACS provides excellent constraints on the <span class="hlt">AGN</span> number counts at the bright end with negligible uncertainties due to cosmic variance, and these constraints are consistent with previous measurements. The depth and areal coverage of SACS is well suited for galaxy cluster surveys outside the local universe, reaching z ˜ 1 for massive clusters. In the second paper, we use Sloan Digital Sky Survey (SDSS) DR8 data to study the 203 extended SACS sources that are located within the SDSS footprint. We search for galaxy over-densities in 3-D space using SDSS galaxies and their photometric redshifts near the Swift galaxy cluster candidates. We find 103 Swift clusters with a > 3σ over-density. The remaining targets are potentially located at higher redshifts and require deeper optical follow-up observations for confirmations as galaxy clusters. We present a series of cluster properties including the redshift, BCG magnitude, BCG-to-X-ray center offset, optical richness, X-ray luminosity and red sequences. We compare the observed redshift distribution of the sample with a theoretical <span class="hlt">model</span>, and find that our sample is complete for z ≤ 0.3 and 80% complete for z ≤ 0.4, consistent with the survey depth of SDSS. We also match our SDSS confirmed Swift clusters to existing cluster catalogs, and find 42, 2 and 1 matches in optical, X-ray and SZ catalogs, respectively, so the majority of these</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19970025807&hterms=Marsden&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DMarsden','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19970025807&hterms=Marsden&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DMarsden"><span>RXTE observations of <span class="hlt">AGN</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rothschild, R. E.; Heindl, W. A.; Blanco, P. R.; Gruber, D. E.; Marsden, D. C.; Pelling, M. R.; Jahoda, K.; Madejski, G.; Swank, J. H.; Zdziarski, A. A.; Gierlinski, M.; Hink, P. L.</p> <p>1997-01-01</p> <p>The Rossi X-ray Timing Explorer (RXTE) observed three active galaxies during its in-orbit verification phase: NGC 4151; NGC 4945, and MCG 8-11-11. All three were detected from 2 keV to more than 100 keV by a combination of the proportional counter array (PCA) and the high energy X-ray timing experiment (HEXTE). The PCA contains five, xenon/methane, multilayer, multiwire, gas proportional counters covering the 2 to 60 keV range, while HEXTE is an array of eight NaI/CsI phoswich scintillation counters covering the 15 to 250 keV range. The three active galaxies represent the classes of Seyfert 1, Seyfert 2 and intermediate Seyfert galaxies. The results of the fitting of various <span class="hlt">models</span> containing partial covering fractions, Compton reflection components and high energy spectral breaks are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AAS...22940205K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AAS...22940205K"><span>The BAT <span class="hlt">AGN</span> Spectroscopic Survey (BASS)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Koss, Michael; Trakhtenbrot, Benny; Ricci, Claudio; Lamperti, Isabella; Oh, Kyuseok; Berney, Simon; Schawinski, Kevin; Balokovic, Mislav; Baronchelli, Linda; Gehrels, Neil; Stern, Daniel; Mushotzky, Richard; Veilleux, Sylvain; Ueda, Yoshihiro; Crenshaw, D. Michael; Harrison, Fiona; Fischer, Travis C.; Treister, Ezequiel; BASS Team; Swift BAT Team</p> <p>2017-01-01</p> <p>We present the Swift BAT <span class="hlt">AGN</span> Spectroscopic Survey (BASS) and discus the first four papers. The catalog represents an unprecedented census of hard-X-ray selected <span class="hlt">AGN</span> in the local universe, with ~90% of sources at z<0.2. Starting from an all-sky catalog of <span class="hlt">AGN</span> detected based on their 14-195 keV flux from the 70-month Swift/BAT catalog, we analyze a total of 1279 optical spectra, taken from twelve dierent telescopes, for a total of 642 spectra of unique <span class="hlt">AGN</span>. We present the absorption and emission line measurements as well as black hole masses and accretion rates for the majority of obscured and un-obscured <span class="hlt">AGN</span> (473), representing more than a factor of 10 increase from past studies. Consistent with previous surveys, we find an increase in the fraction of un-obscured (type 1) <span class="hlt">AGN</span>, as measured from broad Hbeta and Halpha, with increasing 14-195 keV and 2-10 keV luminosity. We find the FWHM of the emission lines to show broad agreement with the X-ray obscuration measurements. Compared to narrow line <span class="hlt">AGN</span> in the SDSS, the X-ray selected <span class="hlt">AGN</span> in our sample with emission lines have a larger fraction of dustier galaxies suggesting these types of galaxies are missed in optical <span class="hlt">AGN</span> surveys using emission line diagnostics. Additionally, we discuss follow-on efforts to study the variation of [OIII] to Xray measurements, a new method to measure accretion rates from using line ratios, a sample of 100 <span class="hlt">AGN</span> observed with NIR spectroscopy, and an effort to measure the accretion rates and obscuration with merger stage in a subsample of mergers.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015yCat..22190001O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015yCat..22190001O"><span>VizieR Online Data Catalog: Catalog of Type-1 <span class="hlt">AGNs</span> from SDSS-DR7 (Oh+, 2015)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Oh, K.; Yi, S. K.; Schawinski, K.; Koss, M.; Trakhtenbrot, B.; Soto, K.</p> <p>2015-08-01</p> <p>We have recently identified a substantial number of type 1 active galactic nuclei (<span class="hlt">AGNs</span>) featuring weak broad-line regions (BLRs) at z<0.2 from detailed analysis of galaxy spectra in the Sloan Digital Sky Survey Data Release 7. These objects predominantly show a stellar continuum but also a broad Hα emission line, indicating the presence of a low-luminosity <span class="hlt">AGN</span> oriented so that we are viewing the central engine directly without significant obscuration. These accreting black holes have previously eluded detection due to their weak nature. The newly discovered BLR <span class="hlt">AGNs</span> have increased the number of known type 1 <span class="hlt">AGNs</span> by 49%. Some of these new BLR <span class="hlt">AGNs</span> were detected with the Chandra X-ray Observatory, and their X-ray properties confirm that they are indeed type 1 <span class="hlt">AGNs</span>. Based on our new and more complete catalog of type 1 <span class="hlt">AGNs</span>, we derived the type 1 fraction of <span class="hlt">AGNs</span> as a function of [OIII]λ5007 emission luminosity and explored the possible dilution effect on obscured <span class="hlt">AGNs</span> due to star formation. The new type 1 <span class="hlt">AGN</span> fraction shows much more complex behavior with respect to black hole mass and bolometric luminosity than has been suggested previously by the existing receding torus <span class="hlt">model</span>. The type 1 <span class="hlt">AGN</span> fraction is sensitive to both of these factors, and there seems to be a sweet spot (ridge) in the diagram of black hole mass and bolometric luminosity. Furthermore, we present the possibility that the Eddington ratio plays a role in determining opening angles. (2 data files).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22348219','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22348219"><span><span class="hlt">Unification</span> of binary star ephemeris solutions</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wilson, R. E.; Van Hamme, W. E-mail: vanhamme@fiu.edu</p> <p>2014-01-10</p> <p>Time-related binary system characteristics such as orbital period, its rate of change, apsidal motion, and variable light-time delay due to a third body, are measured in two ways that can be mutually complementary. The older way is via eclipse timings, while ephemerides by simultaneous whole light and velocity curve analysis have appeared recently. Each has its advantages, for example, eclipse timings typically cover relatively long time spans while whole curves often have densely packed data within specific intervals and allow access to systemic properties that carry additional timing information. Synthesis of the two information sources can be realized in a one step process that combines several data types, with automated weighting based on their standard deviations. Simultaneous light-velocity-timing solutions treat parameters of apsidal motion and the light-time effect coherently with those of period and period change, allow the phenomena to interact iteratively, and produce parameter standard errors based on the quantity and precision of the curves and timings. The logic and mathematics of the <span class="hlt">unification</span> algorithm are given, including computation of theoretical conjunction times as needed for generation of eclipse timing residuals. Automated determination of eclipse type, recovery from inaccurate starting ephemerides, and automated data weighting are also covered. Computational examples are given for three timing-related cases—steady period change (XY Bootis), apsidal motion (V526 Sagittarii), and the light-time effect due to a binary's reflex motion in a triple system (AR Aurigae). Solutions for all combinations of radial velocity, light curve, and eclipse timing input show consistent results, with a few minor exceptions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApJ...833...98C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApJ...833...98C"><span>AGNfitter: A Bayesian MCMC Approach to Fitting Spectral Energy Distributions of <span class="hlt">AGNs</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Calistro Rivera, Gabriela; Lusso, Elisabeta; Hennawi, Joseph F.; Hogg, David W.</p> <p>2016-12-01</p> <p>We present AGNfitter, a publicly available open-source algorithm implementing a fully Bayesian Markov Chain Monte Carlo method to fit the spectral energy distributions (SEDs) of active galactic nuclei (<span class="hlt">AGNs</span>) from the sub-millimeter to the UV, allowing one to robustly disentangle the physical processes responsible for their emission. AGNfitter makes use of a large library of theoretical, empirical, and semi-empirical <span class="hlt">models</span> to characterize both the nuclear and host galaxy emission simultaneously. The <span class="hlt">model</span> consists of four physical emission components: an accretion disk, a torus of <span class="hlt">AGN</span> heated dust, stellar populations, and cold dust in star-forming regions. AGNfitter determines the posterior distributions of numerous parameters that govern the physics of <span class="hlt">AGNs</span> with a fully Bayesian treatment of errors and parameter degeneracies, allowing one to infer integrated luminosities, dust attenuation parameters, stellar masses, and star-formation rates. We tested AGNfitter’s performance on real data by fitting the SEDs of a sample of 714 X-ray selected <span class="hlt">AGNs</span> from the XMM-COSMOS survey, spectroscopically classified as Type1 (unobscured) and Type2 (obscured) <span class="hlt">AGNs</span> by their optical-UV emission lines. We find that two independent <span class="hlt">model</span> parameters, namely the reddening of the accretion disk and the column density of the dusty torus, are good proxies for <span class="hlt">AGN</span> obscuration, allowing us to develop a strategy for classifying <span class="hlt">AGNs</span> as Type1 or Type2, based solely on an SED-fitting analysis. Our classification scheme is in excellent agreement with the spectroscopic classification, giving a completeness fraction of ˜ 86 % and ˜ 70 % , and an efficiency of ˜ 80 % and ˜ 77 % , for Type1 and Type2 <span class="hlt">AGNs</span>, respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1038008','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1038008"><span>The 60-month all-sky BAT Survey of <span class="hlt">AGN</span> and the Anisotropy of Nearby <span class="hlt">AGN</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ajello, M.; Alexander, D.M.; Greiner, J.; Madejski, G.M.; Gehrels, N.; Burlon, D.; /Garching, Max Planck Inst., MPE</p> <p>2012-04-02</p> <p>Surveys above 10 keV represent one of the the best resources to provide an unbiased census of the population of Active Galactic Nuclei (<span class="hlt">AGN</span>). We present the results of 60 months of observation of the hard X-ray sky with Swift/BAT. In this timeframe, BAT detected (in the 15-55 keV band) 720 sources in an all-sky survey of which 428 are associated with <span class="hlt">AGN</span>, most of which are nearby. Our sample has negligible incompleteness and statistics a factor of {approx}2 larger over similarly complete sets of <span class="hlt">AGN</span>. Our sample contains (at least) 15 bona-fide Compton-thick <span class="hlt">AGN</span> and 3 likely candidates. Compton-thick <span class="hlt">AGN</span> represent a {approx}5% of <span class="hlt">AGN</span> samples detected above 15 keV. We use the BAT dataset to refine the determination of the LogN-LogS of <span class="hlt">AGN</span> which is extremely important, now that NuSTAR prepares for launch, towards assessing the <span class="hlt">AGN</span> contribution to the cosmic X-ray background. We show that the LogN-LogS of <span class="hlt">AGN</span> selected above 10 keV is now established to a {approx}10% precision. We derive the luminosity function of Compton-thick <span class="hlt">AGN</span> and measure a space density of 7.9{sub -2.9}{sup +4.1} x 10{sup -5} Mpc{sup -3} for objects with a de-absorbed luminosity larger than 2 x 10{sup 42} erg s{sup -1}. As the BAT <span class="hlt">AGN</span> are all mostly local, they allow us to investigate the spatial distribution of <span class="hlt">AGN</span> in the nearby Universe regardless of absorption. We find concentrations of <span class="hlt">AGN</span> that coincide spatially with the largest congregations of matter in the local ({le} 85 Mpc) Universe. There is some evidence that the fraction of Seyfert 2 objects is larger than average in the direction of these dense regions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009PhDT.........1D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009PhDT.........1D"><span>Spitzer's contribution to the <span class="hlt">AGN</span> population</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Donley, Jennifer Lynn</p> <p>2009-06-01</p> <p>Using large multiwavelength datasets, we study obscured <span class="hlt">AGN</span> in the distant universe that have been missed via traditional selection techniques (e.g. UV/ optical/X-ray). To do so, we take particular advantage of the mid-IR, which is minimally affected by obscuration. We first select as <span class="hlt">AGN</span> candidates those objects whose radio emission is significantly brighter, relative to the mid-IR, than would be predicted by the well known radio/infrared correlation, indicating that the radio emission originates in the central engine. We find that of the 27 such sources identified in the CDF-N, 60% lack solid X-ray detections and 25% lack even 2s X-ray emission. The absorbing columns of the faint X-ray-detected objects indicate that they are obscured but unlikely to be Compton thick, whereas the radio-excess <span class="hlt">AGN</span> which are X-ray non-detected are Compton-thick candidates. We similarly use the infrared emission to select IRAC (3.6-8.0 mm) power-law <span class="hlt">AGN</span>. In these luminous <span class="hlt">AGN</span>, the hot dust emission from the <span class="hlt">AGN</span> fills in the gap in a galaxy's SED between the 1.6 mm stellar bump and the long-wavelength dust emission feature. While sources selected in this way are more luminous than the radio-excess <span class="hlt">AGN</span>, we find a similar X-ray detection fraction. Of the 62 power- law galaxies in the CDF-N, only 55% are detected in the X-ray, and 15% lack evidence for even weak 2s X-ray emission. A study of their X-ray properties indicates that ~ 75% are obscured. Finally, we test IRAC color-color and infrared-excess selection criteria. We find that while these selection techniques identify a number of obscured <span class="hlt">AGN</span>, they may also select a significant number of star-forming galaxies. By combining only the secure <span class="hlt">AGN</span> candidates selected via all methods discussed above, we estimate that the addition of Spitzer-selected <span class="hlt">AGN</span> candidates to the deepest X-ray selected <span class="hlt">AGN</span> samples directly increases the number of known <span class="hlt">AGN</span> by 54-77%, and implies a total increase to the number of <span class="hlt">AGN</span> of 71-94%.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AAS...21714256R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AAS...21714256R"><span>Starburst and <span class="hlt">AGN</span> Indicators in Optically Faint X-ray Sources in the Cosmic Evolution Survey</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Robins, Derek; Elvis, M.; Civano, F.</p> <p>2011-01-01</p> <p>A sample of 55 faint, X-ray selected objects were chosen for analysis from the COSMOS survey with high quality Keck DEIMOS data. The average redshift of the sample was 1.36, consistent with the average redshift of type 1 <span class="hlt">AGN</span> in COSMOS of 1.4. Emission lines, NeV - an indicator of <span class="hlt">AGN</span> luminosity - and OII - an indicator of star formation rate, were measured for a subset of 34 objects. Line properties for these objects were measured. The combination of the two lines is evidence for significant star formation in these obscured <span class="hlt">AGN</span>. Differences between OII and NeV redshifts were measured carefully. Significant differences between OII and NeV redshifts were found in 10-14 objects, implying OII outflows. The results are consistent with current <span class="hlt">models</span> of galaxy evolution that invoke an interplay between <span class="hlt">AGN</span> activity and star formation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2011-03-21/pdf/2011-6720.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2011-03-21/pdf/2011-6720.pdf"><span>76 FR 15209 - 150th Anniversary of the <span class="hlt">Unification</span> of Italy, 2011</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2011-03-21</p> <p>... the <span class="hlt">Unification</span> of Italy, 2011 By the President of the United States of America A Proclamation On March 17, Italy celebrates the 150th anniversary of its <span class="hlt">unification</span> as a single state. On this day, we... own Union, Giuseppe Garibaldi's campaign for the <span class="hlt">unification</span> of Italy inspired many around the...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015toru.conf..F03K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015toru.conf..F03K"><span>Quasar <span class="hlt">Unification</span> Via Disk Winds: From Phenomenology to Physics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Knigge, C.</p> <p>2015-09-01</p> <p>I will give an overview of a collaborative project aimed at testing the viability of QSO <span class="hlt">unification</span> via accretion disk winds. In this scenario, most of the characteristic spectral features of QSOs are formed in these outflows. More specifically, broad absorption lines (BALs) are produced for sight lines within the outflow, while broad emission lines (BELs) are observed for other viewing angles. In order to test these ideas, we use a state-of- the-art Monte Carlo radiative transfer and photoionization code to predict emergent spectra for a wide range of viewing angles and quasar properties (black hole mass, accretion rate, X-ray luminosity, etc). It turns out to be relatively straightforward to produce BALs, but harder to obtain sufficiently strong BELs. We also find that it is easy to overionize the wind with realistic X-ray luminosities. In addition, we are using our code to test and improve hydrodynamic disk wind <span class="hlt">models</span> for quasars. So far, we have been able to demonstrate that the treatment of ionization in existing hydrodynamic <span class="hlt">models</span> of line-driven disk winds is too simplistic to yield realistic results: the <span class="hlt">modelled</span> outflows would be strongly overionized and hence would not feel the line-driving forces that are asssumed to produce them. We have therefore embarked on an effort to <span class="hlt">model</span> line-driven disk winds self-consistently by linking a hydrodynamics code with our ionization and radiative transfer code. Finally, we can also predict the reverberation signatures produced by disk winds, which can be directly compared to the results of the latest reverberation mapping campaigns.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016sf2a.conf...57G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016sf2a.conf...57G"><span>Understanding Active Galactic Nuclei using near-infrared high angular resolution polarimetry I : Mont<span class="hlt">AGN</span> - STOKES comparison</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Grosset, L.; Marin, F.; Gratadour, D.; Goosmann, R.; Rouan, D.; Clénet, Y.; Pelat, D.; Rojas Lobos, P. A.</p> <p>2016-12-01</p> <p>In this first research note of a series of two, we present a comparison between two Monte Carlo radiative transfer codes: Mont<span class="hlt">AGN</span> and STOKES. Both were developed in order to better understand the observed polarisation of Active Galactic Nuclei (<span class="hlt">AGN</span>). Our final aim is to use these radiative transfer codes to simulate the polarisation maps of a prototypical type-2 radio-quiet <span class="hlt">AGN</span> on a wide range of wavelengths, from the infrared band with Mont<span class="hlt">AGN</span> to the X-ray energies with STOKES. Doing so, we aim to analyse in depth the recent SPHERE/IRDIS polarimetric observations conducted on NGC 1068. In order to validate the codes and obtain preliminary results, we set for both codes a common and simple <span class="hlt">AGN</span> <span class="hlt">model</span>, and compared their polaro-imaging results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001ASPC..249..389W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001ASPC..249..389W"><span>X-Ray Properties of the Central kpc of <span class="hlt">AGN</span> and Starbursts: The Latest News from Chandra</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Weaver, Kimberly A.</p> <p></p> <p>The X-ray properties of 15 nearby (v < 3000 kms-1) galaxies that possess <span class="hlt">AGN</span> and/or starbursts are discussed. Two-thirds have nuclear extended emission on scales from ~0.5 to ~1.5 kpc that is either clearly associated with a nuclear outflow or morphologically resembles an outflow. Galaxies that are <span class="hlt">AGN</span>-dominated tend to have linear structures while starburst-dominated galaxies tend to have plume-like structures. Significant X-ray absorption is present in the starburst regions, indicating that a circumnuclear starburst is sufficient to block an <span class="hlt">AGN</span> at optical wavelengths. Galaxies with starburst activity possess more X-ray point sources within their central kpc than non-starbursts. Many of these sources are more luminous than typical X-ray binaries. The Chandra results are discussed in terms of the starburst--<span class="hlt">AGN</span> connection, a revised unified <span class="hlt">model</span> for <span class="hlt">AGN</span>, and possible evolutionary scenarios.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012xmm..prop..151L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012xmm..prop..151L"><span>Resolving <span class="hlt">AGN</span> with PanSTARRS transients</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lawrence, Andy</p> <p>2012-10-01</p> <p>With PanSTARRS we have discovered a new class of slow, blue nuclear transients which we believe to be rare examples of background <span class="hlt">AGN</span> microlensed by stars in foreground galaxies, amplified by a factor of 10--100. The background <span class="hlt">AGN</span> should be somewhat resolved by the foreground lens, providing a unique new diagnostic of <span class="hlt">AGN</span> size and structure - the UV, optical, IR, BLR, and X-ray regions should have differing evolutions during the event. This proposal is a first step towards understanding the structure of the X-ray source : testing the microlensing hypothesis, characterising the SED, and establishing the first two epochs in an expected gradual decline.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014cosp...40E2375O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014cosp...40E2375O"><span>Looking for the broad emission lines in <span class="hlt">AGN</span>2 with deep NIR spectroscopy and the measure of the mass of Intermediate Mass BH</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Onori, Francesca; La Franca, Fabio; Ricci, Federica</p> <p></p> <p>According to the current <span class="hlt">models</span> of galaxy evolution, in a hierarchical cosmology low mass Black Holes (10 (4) - 10 (7) M_⊙) at low redshift contain clues about the formation of the first Black Holes and Galaxies. Moreover, as they extend the dynamic range of the BH-mass/galaxy scaling relations to extreme values, they could be very useful in constraining the <span class="hlt">AGN</span>/Galaxy co-evolutionary <span class="hlt">models</span>. In the past years, in the framework of the verification of the <span class="hlt">AGN</span> unified <span class="hlt">model</span>, there have been several attempts to detect faint broad emission lines in type 2 <span class="hlt">AGN</span> with both NIR and polarised spectroscopy. We here present the new results from a systematic study, performed using deep NIR (VLT and LBT) spectroscopy, of about 50 <span class="hlt">AGN</span>2, drawn from the complete SWIFT/BAT 22-month had X-ray selected sample. A new virial relation able to measure the BH mass using the broad component of the Paschenbeta line will be also presented. Thanks to the above relation we have been able to directly measure, when the BLR has been detected, the BH mass of type 2 <span class="hlt">AGNs</span>, finding that <span class="hlt">AGN</span>2 show on average lower masses than the <span class="hlt">AGN</span>1 population. The implications to the <span class="hlt">AGN</span> unified <span class="hlt">model</span> and <span class="hlt">AGN</span>/galaxy co-evolution scenarios will be discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012BAAA...55..305L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012BAAA...55..305L"><span>Evolución en Núcleos Activos de Galaxias y QSOs I. Relación Starbursts y <span class="hlt">AGNs</span> en Galaxias Próximas</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lípari, S.; Merlo, D.; Moyano, M.</p> <p></p> <p>We have started a new part of our program: ``Study of Evolution of <span class="hlt">AGNs</span> & QSOs''. This new part is mainly a study of the relation between Starbursts and <span class="hlt">AGNs</span>-QSOs in nearby galaxies (using our <span class="hlt">model</span> of Evolutive, Composite & Explosive <span class="hlt">AGNs</span>-QSOs). In particular, we have started spectrophotometric and imaging observations at CASLEO, Bosque Alegre, Gemini, Calar Alto, etc. This study also includes the analysis of Archive Data. Here we show our first results for NGC 1097. FULL TEXT IN SPANISH</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApJ...832..111J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApJ...832..111J"><span>Differences in Halo-scale Environments between Type 1 and Type 2 <span class="hlt">AGNs</span> at Low Redshift</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jiang, Ning; Wang, Huiyuan; Mo, Houjun; Dong, Xiao-Bo; Wang, Tinggui; Zhou, Hongyan</p> <p>2016-12-01</p> <p>Using low-redshift (z\\lt 0.09) samples of active galactic nuclei (<span class="hlt">AGNs</span>), normal galaxies and groups of galaxies selected from the Sloan Digital Sky Survey, we study the environments of Type 1 and Type 2 <span class="hlt">AGNs</span>, both on small and large scales. Comparisons are made for galaxy samples matched in redshift, r-band luminosity, [O iii] luminosity, and also the position in groups (central or satellite). We find that Type 2 <span class="hlt">AGNs</span> and normal galaxies reside in similar environments. Type 1 and Type 2 <span class="hlt">AGNs</span> have similar clustering properties on large scales (≳ 1 {h}-1 {Mpc}), but at scales smaller than 100 {h}-1 {kpc}, Type 2s have significantly more neighbors than Type 1s (3.09 ± 0.69 times more for central <span class="hlt">AGNs</span> at ≲ 30 {h}-1 {kpc}). These results suggest that Type 1 and Type 2 <span class="hlt">AGNs</span> are hosted by halos of similar masses, as can also be seen directly from the mass distributions of their host groups (˜ {10}12 {h}-1 {M}⊙ for centrals and ˜ {10}13 {h}-1 {M}⊙ for satellites). Type 2s have significantly more satellites around them, and the distribution of their satellites is also more centrally concentrated. The host galaxies of both types of <span class="hlt">AGNs</span> have similar optical properties, but their infrared colors are significantly different. Our results suggest that the simple unified <span class="hlt">model</span> based solely on torus orientation is not sufficient, but that galaxy interactions in dark matter halos must have played an important role in the formation of the dust structure, which obscures <span class="hlt">AGNs</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Review+AND+Nationalism&pg=4&id=EJ471766','ERIC'); return false;" href="http://eric.ed.gov/?q=Review+AND+Nationalism&pg=4&id=EJ471766"><span>Growing Together, Coming Apart: German Society since <span class="hlt">Unification</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Torpey, John</p> <p>1993-01-01</p> <p>Reviews the impact of German <span class="hlt">unification</span> on German society, politics, and culture. Contends that four decades of separation created political and cultural differences that are difficult to overcome. Expresses concern about the growth of intolerant attitudes and nationalism among citizens of the former East Germany. (CFR)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=inequalities+AND+social&pg=3&id=EJ1019347','ERIC'); return false;" href="http://eric.ed.gov/?q=inequalities+AND+social&pg=3&id=EJ1019347"><span>Educational Systems and Rising Inequality: Eastern Germany after <span class="hlt">Unification</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>von Below, Susanne; Powell, Justin J. W.; Roberts, Lance W.</p> <p>2013-01-01</p> <p>Educational systems considerably influence educational opportunities and the resulting social inequalities. Contrasting institutional regulations of both structures and contents, the authors present a typology of educational system types in Germany to analyze their effects on social inequality in eastern Germany after <span class="hlt">unification</span>. After 1990, the…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17930741','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17930741"><span>Gauge coupling <span class="hlt">unification</span> and light exotica in string theory.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Raby, Stuart; Wingerter, Akin</p> <p>2007-08-03</p> <p>In this Letter we consider the consequences for the CERN Large Hadron Collider of light vectorlike exotica with fractional electric charge. It is shown that such states are found in orbifold constructions of the heterotic string. Moreover, these exotica are consistent with gauge coupling <span class="hlt">unification</span> at one loop, even though they do not come in complete multiplets of SU(5).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AIPC.1126..141B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AIPC.1126..141B"><span>Compton Reflection in <span class="hlt">AGN</span> with Simbol-X</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Beckmann, V.; Courvoisier, T. J.-L.; Gehrels, N.; Lubiński, P.; Malzac, J.; Petrucci, P. O.; Shrader, C. R.; Soldi, S.</p> <p>2009-05-01</p> <p><span class="hlt">AGN</span> exhibit complex hard X-ray spectra. Our current understanding is that the emission is dominated by inverse Compton processes which take place in the corona above the accretion disk, and that absorption and reflection in a distant absorber play a major role. These processes can be directly observed through the shape of the continuum, the Compton reflection hump around 30 keV, and the iron fluorescence line at 6.4 keV. We demonstrate the capabilities of Simbol-X to constrain complex <span class="hlt">models</span> for cases like MCG-05-23-016, NGC 4151, NGC 2110, and NGC 4051 in short (10 ksec) observations. We compare the simulations with recent observations on these sources by INTEGRAL, Swift and Suzaku. Constraining reflection <span class="hlt">models</span> for <span class="hlt">AGN</span> with Simbol-X will help us to get a clear view of the processes and geometry near to the central engine in <span class="hlt">AGN</span>, and will give insight to which sources are responsible for the Cosmic X-ray background at energies >20 keV.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21255166','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21255166"><span>Reconfinement shocks in relativistic <span class="hlt">AGN</span> jets</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Nalewajko, Krzysztof; Sikora, Marek</p> <p>2008-12-24</p> <p>Stationary knots observed in many <span class="hlt">AGN</span> jets can be explained in terms of a reconfinement shock that forms when relativistic flow of the jet matter collides with the external medium. The position of these knots can be used, together with information on external pressure profile, to constrain dynamical parameters of the jet. We present a semi-analytical <span class="hlt">model</span> for the dynamical structure of reconfinement shocks, taking into account exact conservation laws both across the shock surface and in the zone of the shocked jet matter. We show that, due to the transverse pressure gradient in the shock zone, the position of the reconfinement is larger than predicted by simple <span class="hlt">models</span>. A portion of kinetic energy is converted at the shock surface to internal energy, with efficiency increasing strongly with both bulk Lorentz factor of the jet matter and the jet half-opening angle. Our <span class="hlt">model</span> may be useful as a framework for <span class="hlt">modeling</span> non-thermal radiation produced within the stationary features.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006HEAD....9.1007T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006HEAD....9.1007T"><span>The Evolution of Obscuration in <span class="hlt">AGN</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Treister, Ezequiel; Urry, M.; Virani, S.</p> <p>2006-09-01</p> <p>One fundamental ingredient in our understanding of the <span class="hlt">AGN</span> population is the ratio of obscured to unobscured <span class="hlt">AGN</span> and whether this ratio depends on other parameters like intrinsic luminosity or redshift. Observationally, deep X-ray surveys found that the obscured <span class="hlt">AGN</span> fraction depends on luminosity. However, the dependence on redshift is less clear. In this work, we constructed the largest sample to date of <span class="hlt">AGN</span> selected in hard X-rays, containing a total of 1229 sources, 631 of them obscured, with a high spectroscopic completeness in order to study the possible dependence of the fraction of obscured sources with redshift and/or luminosity. We confirm that this fraction decreases with increasing luminosity as previously reported and found that at the same time it increases with increasing redshift. This is the first time that this evolution is significantly detected using only optical spectroscopy to separate obscured and unobscured <span class="hlt">AGN</span>. Additionally, we use the spectral shape and intensity of the X-ray background as a separate constraint on the evolution of the obscured <span class="hlt">AGN</span> fraction finding consistent results. This result can be interpreted as an evolution in the location of the obscuration, from the central parsec-scale region (the torus) at low redshift to kiloparsec scales (the host galaxy) at high redshift, as it is known that most galaxies contained more dust in the past. Using these results, we calculate the integrated bolometric <span class="hlt">AGN</span> emission finding it to be at most 5% of the total extragalactic light. Hence, while <span class="hlt">AGN</span> contribute most of the light at X-ray wavelengths, they constitute only a small fraction of the integrated extragalactic light. We thank the support of the Centro de Astrof\\'{\\i}sica FONDAP and from NASA/{\\it INTEGRAL} grant NNG05GM79G.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016agnw.confE..32P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016agnw.confE..32P"><span>First Detections of Compact <span class="hlt">AGN</span>-triggered Radio Cores in RQ <span class="hlt">AGNs</span> in the ECDFS</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Prandoni, I.; Maini, A.; Norris, R. P.; Giovannini, G.; Spitler, L. R.</p> <p>2016-08-01</p> <p>The mechanism triggering the radio emission in Radio-Quiet (RQ) Active Galactic Nuclei (<span class="hlt">AGN</span>), found to be a relevant component of the faint radio population in deep fields, is hotly debated. Most RQ <span class="hlt">AGNs</span> are unresolved or barely resolved at a few arcsec scale, comparable to the host galaxy size. RQ <span class="hlt">AGNs</span> have also been found to share many properties with Star Forming Galaxies (SFG). They have similar radio luminosities and similar optical- /infrared-to-radio flux ratios. Their radio luminosity functions show similar evolutionary trends, and their host galaxies have similar colours, optical morphologies and stellar masses. For all these reasons it was concluded that the radio emission in such RQ <span class="hlt">AGNs</span> is mainly triggered by star formation (SF). However in the local Universe (z<0.5) it is well known that both <span class="hlt">AGN</span> and SF processes can contribute to the total radio emission in RQ <span class="hlt">AGNs</span> (see e.g., Seyfert 2 galaxies), and there is growing evidence that composite SF/<span class="hlt">AGN</span> systems are common at mid to high redshift (z>1-2). We used the Australian Long Baseline Array to observe a number of RQ <span class="hlt">AGNs</span> in the Extended Chandra Deep Field South (ECDFS), and we detected compact, high-surface-brightness radio cores in some of them. Our pilot study shows that at least some of the sources classified as radio quiet contain an <span class="hlt">AGN</span> that can contribute significantly (~50% or more) to the total radio emission. This is a first direct evidence of the presence of such <span class="hlt">AGN</span>-triggered radio emission in RQ <span class="hlt">AGNs</span> at cosmological redshifts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015IAUGA..2254320T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015IAUGA..2254320T"><span>The <span class="hlt">AGN</span> Population and the Cosmic X-ray Background</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Treister, Ezequiel; Urry, C. Meg; Schawinski, Kevin</p> <p>2015-08-01</p> <p>In order to fully understand galaxy formation we need to know when in the cosmic history are supermassive black holes (SMBHs) growing more intensively, in what type of galaxies this growth is happening and what fraction of these sources are invisible at most wavelengths due to obscuration. Active Galactic Nuclei (<span class="hlt">AGN</span>) population synthesis <span class="hlt">models</span> that can explain the spectral shape and intensity of the cosmic X-ray background (CXRB) indicate that most of the SMBH growth occurs in moderate-luminosity (Lx~1044 erg/s) sources (Seyfert-type <span class="hlt">AGN</span>), at z~0.5-1 and in heavily obscured but Compton-thin, NH~1023 cm-2, systems.However, this is not the complete history, as a large fraction of black hole growth does not emit significantly in X-rays either due to obscuration, intrinsic low luminosities or large distances. Using a combination of X-ray stacking and multi wavelength selection techniques we constrain the amount of black hole accretion as a function of cosmic history, from z~0 to z~6. The integrated intensity at high energies indicates that a significant fraction of the total black hole growth, 22%, occurs in heavily-obscured systems that are not individually detected in even the deepest X-ray observations.We finally investigate the <span class="hlt">AGN</span> triggering mechanism as a function of bolometric luminosity, finding evidence for a strong connection between significant black hole growth events and major galaxy mergers from z~0 to z~3, while less spectacular but longer accretion episodes are most likely due to other (stochastic) processes. <span class="hlt">AGN</span> activity triggered by major galaxies is responsible for ~60% of the total black hole growth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013RAA....13..899L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013RAA....13..899L"><span>Triggering star formation by both radiative and mechanical <span class="hlt">AGN</span> feedback</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Chao; Gan, Zhao-Ming; Xie, Fu-Guo</p> <p>2013-08-01</p> <p>We perform two dimensional hydrodynamic numerical simulations to study the positive active galactic nucleus (<span class="hlt">AGN</span>) feedback which triggers, rather than suppresses, star formation. Recently, it was shown by Nayakshin et al. and Ishibashi et al. that star formation occurs when the cold interstellar medium (ISM) is squeezed by the impact of mass outflow or radiation pressure, respectively. Mass outflow is ubiquitous in this astrophysical context, and radiation pressure is also important if the <span class="hlt">AGN</span> is luminous. For the first time in this subject, we incorporate both mass outflow feedback and radiative feedback into our <span class="hlt">model</span>. Consequently, the ISM is shocked into shells by the <span class="hlt">AGN</span> feedback, and these shells soon fragment into clumps and filaments because of Rayleigh-Taylor and thermal instabilities. We have two major findings: (1) the star formation rate can indeed be very large in the clumps and filaments. However, the resultant star formation rate density is too large compared with previous works, which is mainly because we ignore the fact that most of the stars that are formed would be disrupted when they move away from the galactic center. (2) Although radiation pressure feedback has a limited effect, when mass outflow feedback is also included, they reinforce each other. Specifically, in the gas-poor case, mass outflow is always the dominant contributor to feedback.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AAS...22931902A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AAS...22931902A"><span><span class="hlt">AGN</span> multi-wavelength identification and host galaxy properties</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Azadi, Mojegan; Coil, Alison L.; MOSDEF Team; PRIMUS Team</p> <p>2017-01-01</p> <p>I present results on <span class="hlt">AGN</span> identification, selection biases, and host galaxy properties at z~2.3 and results on the relation between <span class="hlt">AGN</span> accretion and star formation activity at z~0.8. In the MOSDEF survey, with a sample of X-ray, IR, and optically selected <span class="hlt">AGN</span> at z~2.3, using rest-frame optical spectra obtained with the Keck/MOSFIRE instrument, I find clear selection biases in identifying <span class="hlt">AGN</span> at these wavelengths. There is a strong bias against identifying <span class="hlt">AGN</span> at any wavelength in low mass galaxies, and an additional bias against identifying IR <span class="hlt">AGN</span> in the most massive galaxies. While <span class="hlt">AGN</span> hosts span a wide range of SFR, IR <span class="hlt">AGN</span> are mainly in less dusty galaxies with relatively higher SFR and optical <span class="hlt">AGN</span> are in dusty galaxies with relatively lower SFR in our sample. X-ray <span class="hlt">AGN</span> selection does not display a bias with host SFR. I also consider the relation between the growth of galaxies and their SMBHs using a large sample of X-ray <span class="hlt">AGN</span> in the PRIMUS survey. I do not find a significant correlation between SFR and <span class="hlt">AGN</span> instantaneous luminosity. However, I find a weak but significant correlation between the average luminosity of <span class="hlt">AGN</span> and SFR, which likely reflects that <span class="hlt">AGN</span> luminosities vary on shorter timescales than host galaxies SFR. My results indicate that <span class="hlt">AGN</span> are also often hosted by quiescent galaxies, and within both the star-forming and quiescent galaxy populations the probability of hosting an <span class="hlt">AGN</span> is a power-law distribution as a function of specific accretion rate. However, at a given stellar mass, I find that a star-forming galaxy is ~2-3 times more likely than a quiescent galaxy to host an <span class="hlt">AGN</span> of a given specific accretion rate. The probability of a galaxy hosting an <span class="hlt">AGN</span> is constant across the main sequence of star formation, while in quiescent galaxies increases with SFR.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015MNRAS.451.4328K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015MNRAS.451.4328K"><span>Are the variability properties of the Kepler <span class="hlt">AGN</span> light curves consistent with a damped random walk?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kasliwal, Vishal P.; Vogeley, Michael S.; Richards, Gordon T.</p> <p>2015-08-01</p> <p>We test the consistency of active galactic nuclei (<span class="hlt">AGN</span>) optical flux variability with the damped random walk (DRW) <span class="hlt">model</span>. Our sample consists of 20 multiquarter Kepler <span class="hlt">AGN</span> light curves including both Type 1 and 2 Seyferts, radio-loud and -quiet <span class="hlt">AGN</span>, quasars, and blazars. Kepler observations of <span class="hlt">AGN</span> light curves offer a unique insight into the variability properties of <span class="hlt">AGN</span> light curves because of the very rapid (11.6-28.6 min) and highly uniform rest-frame sampling combined with a photometric precision of 1 part in 105 over a period of 3.5 yr. We categorize the light curves of all 20 objects based on visual similarities and find that the light curves fall into five broad categories. We measure the first-order structure function of these light curves and <span class="hlt">model</span> the observed light curve with a general broken power-law power spectral density (PSD) characterized by a short-time-scale power-law index γ and turnover time-scale τ. We find that less than half the objects are consistent with a DRW and observe variability on short time-scales (˜2 h). The turnover time-scale τ ranges from ˜10-135 d. Interesting structure function features include pronounced dips on rest-frame time-scales ranging from 10-100 d and varying slopes on different time-scales. The range of observed short-time-scale PSD slopes and the presence of dip and varying slope features suggests that the DRW <span class="hlt">model</span> may not be appropriate for all <span class="hlt">AGN</span>. We conclude that <span class="hlt">AGN</span> variability is a complex phenomenon that requires a more sophisticated statistical treatment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002PhRvD..66g5004H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002PhRvD..66g5004H"><span>Complete theory of grand <span class="hlt">unification</span> in five dimensions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hall, Lawrence J.; Nomura, Yasunori</p> <p>2002-10-01</p> <p>A fully realistic unified theory is constructed, with SU(5) gauge symmetry and supersymmetry both broken by boundary conditions in a fifth dimension. Despite the resulting explicit breaking of SU(5) locally at a boundary of the dimension, when the size of the extra dimension is taken to be large precise predictions emerge for gauge coupling <span class="hlt">unification</span>, αs(MZ)=0.118+/-0.003, and for Yukawa coupling <span class="hlt">unification</span>, mb(MZ)=3.3+/-0.2 GeV. The 5D theory is then valid over a large energy interval from the compactification scale, Mc~=1×1015 GeV, to the scale of strong coupling, Ms~=1×1017 GeV. A complete understanding of the Higgs sector of the minimal supersymmetric standard <span class="hlt">model</span> is given, with explanations for why the Higgs triplets are heavy, why the Higgs doublets are protected from a large tree-level mass, and why the μ and B parameters are naturally generated to be of order the supersymmetry breaking scale. All sources of proton decay from operators of dimension four and five are forbidden, while a new origin for baryon number violating dimension six operators is found to be important. The exchange of the superheavy gauge boson, with a brane-localized kinetic energy interaction, leads to τp~1034 yr, with several branching ratios determined in terms of a single mixing parameter. The theory is only realistic for an essentially unique choice of matter location in the fifth dimension: the ten-plets of the first two generations must lie in the bulk, with all other matter located on the SU(5) preserving boundary. Several aspects of flavor follow from this geometry: only the third generation possesses an SU(5) mass relation, and the lighter two generations have only small mixings with the heaviest generation except for neutrinos. The entire superpartner spectrum is predicted in terms of only two free parameters. The squark and slepton masses have sizes determined by their location in the fifth dimension, allowing a significant experimental test of the detailed</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016agnw.confE..18F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016agnw.confE..18F"><span>Nebular emission from <span class="hlt">AGN</span> in the ultraviolet/optical: diagnostics of the ionizing source and gas properties</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Feltre, A.</p> <p>2016-08-01</p> <p>Spectroscopic studies of active galactic nuclei (<span class="hlt">AGN</span>) are powerful means of probing the physical properties of the ionized gas within them. In particular, forthcoming facilities such as JWST and the E-ELT, will provide rest-frame ultraviolet and optical spectra of the very distant <span class="hlt">AGN</span>. To lay the groundwork for the interpretation of these revolutionary datasets, we have recently computed new photoionization <span class="hlt">models</span> of the narrow-line emitting regions (NLR) of <span class="hlt">AGN</span> and combined them with similar <span class="hlt">models</span> of the nebular emission from star-forming galaxies. In this talk, I will first describe how new ultraviolet and standard optical spectral diagnostics allow one to distinguish between nuclear activity and star formation. I will then explain how predictions of <span class="hlt">AGN</span> nebular emission can be best used to understand the physical properties of the <span class="hlt">AGN</span> NLR gas. In particular, I will present recent results from a study on one of the most comprehensive set of optical spectra (from VIMOS/VLT) sampling the rest-frame ultraviolet range of ~90 type 2 <span class="hlt">AGN</span> (1.5 < z < 3), drawn from the z-COSMOS deep survey. To conclude, I will show how the implementation of <span class="hlt">AGN</span> photoionization calculations in an innovative Bayesian fitting code can help us best interpret current, and future, spectro-photometric data on active galaxies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011A%26A...535A..73H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011A%26A...535A..73H"><span>Photometric <span class="hlt">AGN</span> reverberation mapping - an efficient tool for BLR sizes, black hole masses, and host-subtracted <span class="hlt">AGN</span> luminosities</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Haas, M.; Chini, R.; Ramolla, M.; Pozo Nuñez, F.; Westhues, C.; Watermann, R.; Hoffmeister, V.; Murphy, M.</p> <p>2011-11-01</p> <p>Photometric reverberation mapping employs a wide band pass to measure the <span class="hlt">AGN</span> continuum variations and a suitable narrow band to trace the echo of an emission line in the broad line region (BLR). The narrow band catches both the emission line and the underlying continuum, and one needs to extract the pure emission line light curve. We performed a test on two local <span class="hlt">AGNs</span>, PG0003+199 and Ark120, by observing well-sampled broad- (B, V) and narrow-band light curves with the robotic 15 cm telescope VYSOS-6 on Cerro Armazones, Chile. We find that, as long as the emission line contributes 50% to the band pass, the pure emission line light curve can be reconstructed from photometric monitoring data so that the time lag τ can be measured. For both objects the lags are consistent with spectroscopic reverberation results. We calculated virial black hole masses in agreement with literature values, by combining the BLR size RBLR (τ) from photometric monitoring with the velocity dispersion of a single contemporaneous spectrum. Applying the flux variation gradient method, we estimate the host galaxy contribution in the apertures used and the host-subtracted restframe 5100 Å luminosity LAGN. Our LAGN differs significantly from previous estimates, placing both sources ~50% closer to the RBLR - LAGN relation. This suggests that the scatter in the current RBLR - LAGN relation is largely caused by uncertainties in RBLR due to undersampled light curves and by uncertainties in the host-subtracted <span class="hlt">AGN</span> luminosities inferred so far. If the scatter can be reduced, then two quasar samples matching in RBLR should also match in intrinsic LAGN, independent of redshift, thus offering the prospect of probing cosmological <span class="hlt">models</span>. Photometric reverberation mapping opens the door to efficiently measuring hundreds of BLR sizes and host-subtracted <span class="hlt">AGN</span> luminosities even with small telescopes, but also routinely with upcoming large survey telescopes like the LSST.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22167210','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22167210"><span>SUPERNOVAE AND <span class="hlt">AGN</span> DRIVEN GALACTIC OUTFLOWS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sharma, Mahavir; Nath, Biman B. E-mail: biman@rri.res.in</p> <p>2013-01-20</p> <p>We present analytical solutions for winds from galaxies with a Navarro-Frank-White (NFW) dark matter halo. We consider winds driven by energy and mass injection from multiple supernovae (SNe), as well as momentum injection due to radiation from a central black hole. We find that the wind dynamics depends on three velocity scales: (1) v{sub *}{approx}( E-dot / 2 M-dot ){sup 1/2} describes the effect of starburst activity, with E-dot and M-dot as energy and mass injection rate in a central region of radius R; (2) v {sub .} {approx} (GM {sub .}/2R){sup 1/2} for the effect of a central black hole of mass M {sub .} on gas at distance R; and (3) v{sub s}=(GM{sub h} / 2Cr{sub s}){sup 1/2}, which is closely related to the circular speed (v{sub c} ) for an NFW halo, where r{sub s} is the halo scale radius and C is a function of the halo concentration parameter. Our generalized formalism, in which we treat both energy and momentum injection from starbursts and radiation from the central active galactic nucleus (<span class="hlt">AGN</span>), allows us to estimate the wind terminal speed to be (4v {sup 2} {sub *} + 6({Gamma} - 1)v {sub .} {sup 2} - 4v {sup 2} {sub s}){sup 1/2}, where {Gamma} is the ratio of force due to radiation pressure to gravity of the central black hole. Our dynamical <span class="hlt">model</span> also predicts the following: (1) winds from quiescent star-forming galaxies cannot escape from 10{sup 11.5} M {sub Sun} {<=} M{sub h} {<=} 10{sup 12.5} M {sub Sun} galaxies; (2) circumgalactic gas at large distances from galaxies should be present for galaxies in this mass range; (3) for an escaping wind, the wind speed in low- to intermediate-mass galaxies is {approx}400-1000 km s{sup -1}, consistent with observed X-ray temperatures; and (4) winds from massive galaxies with <span class="hlt">AGNs</span> at Eddington limit have speeds {approx}> 1000 km s{sup -1}. We also find that the ratio [2v {sup 2} {sub *} - (1 - {Gamma})v {sub .} {sup 2}]/v {sup 2} {sub c} dictates the amount of gas lost through winds. Used in conjunction with</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1987PhST...15....5B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1987PhST...15....5B"><span>CHAIRMEN'S PREFACE AND EDITORS' NOTE: <span class="hlt">Unification</span> of Fundamental Interactions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brink, Lars; Nilsson, Jan S.; Salomonson, Per; Skagerstam, Bo-Sture</p> <p>1987-01-01</p> <p>Chairmen's PrefaceIn 1984 we obtained a grant from the Nobel Foundation to organize a Nobel Symposium on "<span class="hlt">Unification</span> of the Fundamental Interactions". In our proposal which we submitted in the fall of 1983 we stated that we wanted to cover the various attempts to <span class="hlt">unification</span> such as GUT'S, supergravity, Kaluza-Klein theories and superstrings. What has happened in particle physics since then is already history. With the realization that certain superstring theories could be anomaly free, it became clear that these <span class="hlt">models</span> could encompass earlier attempts to <span class="hlt">unification</span> as well as solving the fundamental problem of quantum gravity. The excitement that some of us had felt for some time now spread through most of the particle physics community and this excitement certainly was evident during the Symposium. With the international advisory committee we originally chose a list of around 30 invitees which could best represent the various subjects listed above. When it came to the final planning of the programme essentially all talks dealt with superstrings! We were very fortunate that almost all of the invitees managed to come to the Symposium. From the western world only three were unable to participate, André Neveu, Steven Weinberg and Bruno Zumino. We certainly missed them during the meeting. We were particularly happy that Stephen Hawking managed to take part actively. Our real problem was to get participants from the Soviet Union. Out of eight invitations only one came through. We were very happy to have Renata Kallosh, who really did her utmost to enlighten us about not only her own work but also about recent progress in the USSR, However, we were very sorry that in spite of all our letters, telegrammes and endless attempts to get telephone calls through and despite the good relations between the Swedish and Soviet Academies of Sciences we had to miss Ludwig Faddeev, Valodja Gribov, Andrej Linde, Victor Ogievetsky, Sasha Polyakov, Misha Shifman and Arkadij</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014IAUS..304..164P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014IAUS..304..164P"><span>The ROSAT/NVSS <span class="hlt">AGN</span> sample</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Paronyan, Gurgen M.; Abrahamyan, Hayk V.; Harutyunyan, Gohar S.; Mickaelian, Areg M.</p> <p>2014-07-01</p> <p>We attempt to create an X-ray/radio <span class="hlt">AGN</span> catalog and make its multiwavelength studies. ROSAT Bright Source Catalogue (BSC) contains 18,806 and ROSAT Faint Source Catalogue (FSC), 105,922 X-ray sources giving the total number of ROSAT X-ray sources 124,727 (one source is listed twice). On the other hand, NVSS radio catalogue contains 1,773,484 sources. Taking into account that X-ray sources contain <span class="hlt">AGN</span>, bright stars and galaxies, clusters, white dwarfs (WD), cataclysmic variables (CV), etc., the cross-identification with radio catalogue may distinguish the extragalactic sources. We have cross-correlated ROSAT catalogs with NVSS one with a search radius 30 arcsec. 9,193 associations have been found. To distinguish <span class="hlt">AGN</span> from the normal bright galaxies and clusters, Veron-Cetty & Veron <span class="hlt">AGN</span> catalog (v.13, 2010; VCV-13) containing 168,940 objects have been used. A cross-correlation of the 9,193 ROSAT/NVSS sources with the VCV-13 with a search radius 30 arcsec resulted in 3,094 associations. Thus we are left with more 6,099 X-ray/radio sources without an optical identification. Brighter objects are normal bright galaxies, while we believe that all faint ones are candidate <span class="hlt">AGN</span> with some contamination of distant clusters. SDSS spectroscopic survey allows us classify objects by activity types, and a number of our candidate <span class="hlt">AGN</span> is found to be present in SDSS. We attempt to find connections between the fluxes in different wavelength ranges, which will allow us to confirm <span class="hlt">AGN</span> and blazars candidates and in some cases find new ones.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015A%26A...583A.120S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015A%26A...583A.120S"><span>Self-consistent two-phase <span class="hlt">AGN</span> torus models⋆. SED library for observers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Siebenmorgen, Ralf; Heymann, Frank; Efstathiou, Andreas</p> <p>2015-11-01</p> <p>We assume that dust near active galactic nuclei (<span class="hlt">AGNs</span>) is distributed in a torus-like geometry, which can be described as a clumpy medium or a homogeneous disk, or as a combination of the two (i.e. a two-phase medium). The dust particles considered are fluffy and have higher submillimeter emissivities than grains in the diffuse interstellar medium. The dust-photon interaction is treated in a fully self-consistent three-dimensional radiative transfer code. We provide an <span class="hlt">AGN</span> library of spectral energy distributions (SEDs). Its purpose is to quickly obtain estimates of the basic parameters of the <span class="hlt">AGNs</span>, such as the intrinsic luminosity of the central source, the viewing angle, the inner radius, the volume filling factor and optical depth of the clouds, and the optical depth of the disk midplane, and to predict the flux at yet unobserved wavelengths. The procedure is simple and consists of finding an element in the library that matches the observations. We discuss the general properties of the <span class="hlt">models</span> and in particular the 10 μm silicate band. The <span class="hlt">AGN</span> library accounts well for the observed scatter of the feature strengths and wavelengths of the peak emission. <span class="hlt">AGN</span> extinction curves are discussed and we find that there is no direct one-to-one link between the observed extinction and the wavelength dependence of the dust cross sections. We show that objects in the library cover the observed range of mid-infrared colors of known <span class="hlt">AGNs</span>. The validity of the approach is demonstrated by matching the SEDs of a number of representative objects: Four Seyferts and two quasars for which we present new Herschel photometry, two radio galaxies, and one hyperluminous infrared galaxy. Strikingly, for the five luminous objects we find that pure <span class="hlt">AGN</span> <span class="hlt">models</span> fit the SED without needing to postulate starburst activity. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.The SED</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011A%26A...536A..35F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011A%26A...536A..35F"><span>Optically faint radio sources: reborn <span class="hlt">AGN</span>?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Filho, M. E.; Brinchmann, J.; Lobo, C.; Antón, S.</p> <p>2011-12-01</p> <p>We present our discovery of several relatively strong radio sources in the field-of-view of SDSS galaxy clusters that have no optical counterparts down to the magnitude limits of the SDSS. The optically faint radio sources appear as double-lobed or core-jet objects in the FIRST radio images and have projected angular sizes ranging from 0.5 to 1.0 arcmin. We followed-up these sources with near-infrared imaging using the wide-field imager HAWK-I on the VLT. We detected Ks-band emitting regions, about 1.5 arcsec in size and coincident with the centers of the radio structures, in all sources, with magnitudes in the range 17-20 mag. We used spectral <span class="hlt">modelling</span> to characterize the sample sources. In general, the radio properties are similar to those observed in 3CRR sources but the optical-radio slopes are consistent with those of moderate to high redshift (z < 4) gigahertz-peaked spectrum sources. Our results suggest that these unusual objects are galaxies whose black hole has been recently re-ignited but that retain large-scale radio structures, which are signatures of previous <span class="hlt">AGN</span> activity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApJ...835..257L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApJ...835..257L"><span>Dust-deficient Palomar-Green Quasars and the Diversity of <span class="hlt">AGN</span> Intrinsic IR Emission</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lyu, Jianwei; Rieke, G. H.; Shi, Yong</p> <p>2017-02-01</p> <p>To elucidate the intrinsic broadband infrared (IR) emission properties of active galactic nuclei (<span class="hlt">AGNs</span>), we analyze the spectral energy distributions (SEDs) of 87 z ≲ 0.5 Palomar-Green (PG) quasars. While the Elvis <span class="hlt">AGN</span> template with a moderate far-IR correction can reasonably match the SEDs of the <span class="hlt">AGN</span> components in ∼60% of the sample (and is superior to alternatives such as that by Assef), it fails on two quasar populations: (1) hot-dust-deficient (HDD) quasars that show very weak emission thoroughly from the near-IR to the far-IR, and (2) warm-dust-deficient (WDD) quasars that have similar hot dust emission as normal quasars but are relatively faint in the mid- and far-IR. After building composite <span class="hlt">AGN</span> templates for these dust-deficient quasars, we successfully fit the 0.3–500 μm SEDs of the PG sample with the appropriate <span class="hlt">AGN</span> template, an infrared template of a star-forming galaxy, and a host galaxy stellar template. 20 HDD and 12 WDD quasars are identified from the SED decomposition, including seven ambiguous cases. Compared with normal quasars, the HDD quasars have <span class="hlt">AGNs</span> with relatively low Eddington ratios and the fraction of WDD quasars increases with <span class="hlt">AGN</span> luminosity. Moreover, both the HDD and WDD quasar populations show relatively stronger mid-IR silicate emission. Virtually identical SED properties are also found in some quasars from z = 0.5 to 6. We propose a conceptual <span class="hlt">model</span> to demonstrate that the observed dust deficiency of quasars can result from a change of structures of the circumnuclear tori that can occur at any cosmic epoch.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AAS...22840008B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AAS...22840008B"><span>Obscuring Torus Geometry from the NuSTAR Survey of Swift/BAT <span class="hlt">AGN</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Balokovic, Mislav; Harrison, Fiona; NuSTAR</p> <p>2016-06-01</p> <p>The Nuclear Spectroscopic Telescope Array (NuSTAR) has enabled studies of the local active galactic nuclei (<span class="hlt">AGN</span>) to extend into the spectral window above 10 keV with unprecedented spatial resolution and two orders of magnitude better sensitivity than any other instrument operating in that energy range. As a part of its long-term extragalactic program NuSTAR is surveying the nearby population of <span class="hlt">AGN</span> detected at hard X-ray energies by the Swift Burst Alert Telescope (Swift/BAT). I will present spectroscopic results based on NuSTAR and Swift observations of ~150 Swift/BAT <span class="hlt">AGN</span> surveyed in the first three years of NuSTAR operation. This sample forms an atlas of the highest quality hard X-ray spectra available to date for a large number of <span class="hlt">AGN</span>, providing unprecedented insight into the variety <span class="hlt">AGN</span> spectra in the hard X-ray band. In addition to phenomenology, which is an essential ingredient of Cosmic X-ray Background studies, it is possible to use new fitting <span class="hlt">models</span> to directly probe the geometry of the toroidal obscurer (torus). Its main spectral features lie within the NuSTAR bandpass, making it possible to test the common assumption that a similar Compton-thick torus exists around essentially every Seyfert-type <span class="hlt">AGN</span>. I will discuss torus geometry constraints based on the X-ray spectra in relation to those from other wavelengths, the effects on interpretation of high-redshift <span class="hlt">AGN</span> observations, and the limitations of the current results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AAS...22730301M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AAS...22730301M"><span>The star formation-<span class="hlt">AGN</span> interplay in merging galaxies: insights from hydrodynamical simulations and observations.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Martinez Galarza, Juan R.; Smith, Howard Alan; Weiner, Aaron; Hayward, Christopher C.; Lanz, Lauranne; Zezas, Andreas; Rosenthal, Lee; Ashby, Matthew</p> <p>2016-01-01</p> <p>Thermal emission from an Active Galactic Nucleus (<span class="hlt">AGN</span>) can provide a significant contribution to the bolometric luminosity of galaxies, and its effect at infrared wavelengths can mimic the process of star-formation, jeopardizing star formation rate (SFR) diagnostics. It is therefore important to <span class="hlt">model</span> the <span class="hlt">AGN</span> emission and to quantify its effect on the estimated SFRs when SED fitting tools are applied. We tackle this problem by studying the dust radiative transfer calculations of hydrodynamically simulated binary galaxy mergers covering a broad range of parameters, including stellar mas ratios, gas contents, <span class="hlt">AGN</span> luminosity and viewing angles. We apply the energy balance SED fitting codes CHIBURST and CIGALE to the mock SEDs of our simulated merger, and then compare with the results of applying the same codes to the SEDs of observed merging galaxies in the Local Universe. At different stages of the interaction, we compare their derived SFRs and <span class="hlt">AGN</span> fractions with those predicted by the hydrodynamical simulations, for a broad range of the interaction parameters, but focus on the stages near coalescence, when the <span class="hlt">AGN</span> contribution exceed 10% of the total luminosity. We show that the contribution to IR luminosity is greatest during and immediately after coalescence, when the two supermassive black holes of the interacting pair merge and undergo and enhanced period of accretion. Under certain conditions, CIGALE succeeds at recovering the SFRs and <span class="hlt">AGN</span> fractions with higher accuracy than other available codes, such as MAGPHYS, even during these extreme stages. Our results show that using the IR luminosity as a simple surrogate for star formation can significantly overestimate the true SFR by underestimating the contribution from the <span class="hlt">AGN</span>. Finally, we study the effect of using different parametric star formation histories (SFHs) when fitting the SEDs of galaxies, and show that a delayed SFH is usually a reasonable choice for merging galaxies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/430780','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/430780"><span>Left-corner <span class="hlt">unification</span>-based natural language processing</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lytinen, S.L.; Tomuro, N.</p> <p>1996-12-31</p> <p>In this paper, we present an efficient algorithm for parsing natural language using <span class="hlt">unification</span> grammars. The algorithm is an extension of left-corner parsing, a bottom-up algorithm which utilizes top-down expectations. The extension exploits <span class="hlt">unification</span> grammar`s uniform representation of syntactic, semantic, and domain knowledge, by incorporating all types of grammatical knowledge into parser expectations. In particular, we extend the notion of the reachability table, which provides information as to whether or not a top-down expectation can be realized by a potential subconstituent, by including all types of grammatical information in table entries, rather than just phrase structure information. While our algorithm`s worst-case computational complexity is no better than that of many other algorithms, we present empirical testing in which average-case linear time performance is achieved. Our testing indicates this to be much improved average-case performance over previous leftcomer techniques.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MNRAS.464.1693H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MNRAS.464.1693H"><span>Cosmology with <span class="hlt">AGN</span> dust time lags-simulating the new VEILS survey</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hönig, S. F.; Watson, D.; Kishimoto, M.; Gandhi, P.; Goad, M.; Horne, K.; Shankar, F.; Banerji, M.; Boulderstone, B.; Jarvis, M.; Smith, M.; Sullivan, M.</p> <p>2017-01-01</p> <p>The time lag between optical and near-infrared continuum emission in active galactic nuclei (<span class="hlt">AGN</span>) shows a tight correlation with luminosity and has been proposed as a standardizable candle for cosmology. In this paper, we explore the use of these <span class="hlt">AGN</span> hot-dust time lags for cosmological <span class="hlt">model</span> fitting under the constraints of the new VISTA Extragalactic Infrared Legacy Survey (VEILS). This new survey will target a 9 deg2 field observed in J and Ks band with a 14-d cadence and will run for 3 yr. The same area will be covered simultaneously in the optical griz bands by the Dark Energy Survey, providing complementary time-domain optical data. We perform realistic simulations of the survey setup, showing that we expect to recover dust time lags for about 450 objects out of a total of 1350 optical type 1 <span class="hlt">AGN</span>, spanning a redshift range of 0.1 < z < 1.2. We use the lags recovered from our simulations to calculate precise distance moduli, establish a Hubble diagram, and fit cosmological <span class="hlt">models</span>. Assuming realistic scatter in the distribution of the dust around the <span class="hlt">AGN</span> as well as in the normalization of the lag-luminosity relation, we are able to constrain Ω _Λ in ΛCDM with similar accuracy as current supernova samples. We discuss the benefits of combining <span class="hlt">AGN</span> and supernovae for cosmology and connect the present work to future attempts to reach out to redshifts of z > 4.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA460613','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA460613"><span>On Deftly Introducing Procedural Elements into <span class="hlt">Unification</span> Parsing</span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p>1990-01-01</p> <p>be represented by a substitution list that binds ?AGR to the disjunction itself, but the following case (AGR ?P ?N) lq (:OR (AGR (2ND) (SNG)) (AGR...identifies the two values by binding them both to a single variable, the conditions for our constrained disjunction are met. However, if the...be unknown in different circumstances. Either class, for example, can be unknown in questions or anaphors . While <span class="hlt">unification</span> can certainly handle</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014MNRAS.443.3538H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014MNRAS.443.3538H"><span>Higher prevalence of X-ray selected <span class="hlt">AGN</span> in intermediate-age galaxies up to z ˜ 1</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hernán-Caballero, Antonio; Alonso-Herrero, Almudena; Pérez-González, Pablo G.; Barro, Guillermo; Aird, James; Ferreras, Ignacio; Cava, Antonio; Cardiel, Nicolás; Esquej, Pilar; Gallego, Jesús; Nandra, Kirpal; Rodríguez-Zaurín, Javier</p> <p>2014-10-01</p> <p>We analyse the stellar populations in the host galaxies of 53 X-ray selected optically dull active galactic nuclei (<span class="hlt">AGN</span>) at 0.34 < z < 1.07 with ultradeep (mAB = 26.5, 3σ) optical medium-band (R ˜ 50) photometry from the Survey for High-z Absorption Red and Dead Sources (SHARDS). The spectral resolution of SHARDS allows us to consistently measure the strength of the 4000 Å break, Dn(4000), a reliable age indicator for stellar populations. We confirm that most X-ray selected moderate-luminosity <span class="hlt">AGN</span> (LX < 1044 erg s-1) are hosted by massive galaxies (typically M* >1010.5 M⊙) and that the observed fraction of galaxies hosting an <span class="hlt">AGN</span> increases with the stellar mass. A careful selection of random control samples of inactive galaxies allows us to remove the stellar mass and redshift dependences of the <span class="hlt">AGN</span> fraction to explore trends with several stellar age indicators. We find no significant differences in the distribution of the rest-frame U - V colour for <span class="hlt">AGN</span> hosts and inactive galaxies, in agreement with previous results. However, we find significantly shallower 4000 Å breaks in <span class="hlt">AGN</span> hosts, indicative of younger stellar populations. With the help of a <span class="hlt">model</span>-independent determination of the extinction, we obtain extinction-corrected U - V colours and light-weighted average stellar ages. We find that <span class="hlt">AGN</span> hosts have younger stellar populations and higher extinction compared to inactive galaxies with the same stellar mass and at the same redshift. We find a highly significant excess of <span class="hlt">AGN</span> hosts with Dn(4000) ˜ 1.4 and light-weighted average stellar ages of 300-500 Myr, as well as a deficit of <span class="hlt">AGN</span> in intrinsic red galaxies. We interpret failure in recognizing these trends in previous studies as a consequence of the balancing effect in observed colours of the age-extinction degeneracy.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22357149','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22357149"><span>Satellites of radio <span class="hlt">AGN</span> in SDSS: Insights into <span class="hlt">agn</span> triggering and feedback</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Pace, Cameron; Salim, Samir E-mail: salims@indiana.edu</p> <p>2014-04-10</p> <p>We study the effects of radio jets on galaxies in their vicinity (satellites) and the role of satellites in triggering radio-loud active galactic nuclei (<span class="hlt">AGNs</span>). The study compares the aggregate properties of satellites of a sample of 7220 radio <span class="hlt">AGNs</span> at z < 0.3 (identified by Best and Heckman from the SDSS and NVSS+FIRST surveys) to the satellites of a control sample of radio-quiet galaxies, which are matched in redshift, color, luminosity, and axis ratio, as well as by environment type: field galaxies, cluster members, and brightest cluster galaxies (BCGs). Remarkably, we find that radio <span class="hlt">AGNs</span> exhibit on average a 50% excess (17σ significance) in the number of satellites within 100 kpc even though the cluster membership was controlled (e.g., radio BCGs have more satellites than radio-quiet BCGs, etc.). Satellite excess is not confirmed for high-excitation sources, which are only 2% of radio <span class="hlt">AGN</span>. Extra satellites may be responsible for raising the probability for hot gas <span class="hlt">AGN</span> accretion via tidal effects or may otherwise enhance the intensity or duration of the radio-emitting phase. Furthermore, we find that the incidence of radio <span class="hlt">AGNs</span> among potential hosts (massive ellipticals) is similar for field galaxies and for non-BCG cluster members, suggesting that <span class="hlt">AGN</span> fueling depends primarily on conditions in the host halo rather than the parent, cluster halo. Regarding feedback, we find that radio <span class="hlt">AGNs</span>, either high or low excitation, have no detectable effect on star formation in their satellites, as neither induced star formation nor star formation quenching is present in more than ∼1% of radio <span class="hlt">AGN</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014ApJ...785...66P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ApJ...785...66P"><span>Satellites of Radio <span class="hlt">AGN</span> in SDSS: Insights into <span class="hlt">AGN</span> Triggering and Feedback</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pace, Cameron; Salim, Samir</p> <p>2014-04-01</p> <p>We study the effects of radio jets on galaxies in their vicinity (satellites) and the role of satellites in triggering radio-loud active galactic nuclei (<span class="hlt">AGNs</span>). The study compares the aggregate properties of satellites of a sample of 7220 radio <span class="hlt">AGNs</span> at z < 0.3 (identified by Best & Heckman from the SDSS and NVSS+FIRST surveys) to the satellites of a control sample of radio-quiet galaxies, which are matched in redshift, color, luminosity, and axis ratio, as well as by environment type: field galaxies, cluster members, and brightest cluster galaxies (BCGs). Remarkably, we find that radio <span class="hlt">AGNs</span> exhibit on average a 50% excess (17σ significance) in the number of satellites within 100 kpc even though the cluster membership was controlled (e.g., radio BCGs have more satellites than radio-quiet BCGs, etc.). Satellite excess is not confirmed for high-excitation sources, which are only 2% of radio <span class="hlt">AGN</span>. Extra satellites may be responsible for raising the probability for hot gas <span class="hlt">AGN</span> accretion via tidal effects or may otherwise enhance the intensity or duration of the radio-emitting phase. Furthermore, we find that the incidence of radio <span class="hlt">AGNs</span> among potential hosts (massive ellipticals) is similar for field galaxies and for non-BCG cluster members, suggesting that <span class="hlt">AGN</span> fueling depends primarily on conditions in the host halo rather than the parent, cluster halo. Regarding feedback, we find that radio <span class="hlt">AGNs</span>, either high or low excitation, have no detectable effect on star formation in their satellites, as neither induced star formation nor star formation quenching is present in more than ~1% of radio <span class="hlt">AGN</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/AD1004294','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/AD1004294"><span>Korean <span class="hlt">Unification</span> and the Future of the U.S.-ROK Alliance</span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p>2016-02-01</p> <p>from December 2012 to April 2015. Key Points ◆◆ <span class="hlt">Unification</span> of the Korean Peninsula would remove the primary threat that has animated the U.S.–Repub...development.4 By eliminating the central threat that has animated the U.S.-ROK alliance, <span class="hlt">unification</span> would also give rise to questions about the future...offensive, render a North Korean aggression scenario, while dangerous , relatively remote. Although peaceful <span class="hlt">unification</span> would be preferred and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AAS...22941402F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AAS...22941402F"><span>Reverberation Mapping of <span class="hlt">AGN</span> Accretion Disks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fausnaugh, Michael; AGN STORM Collaboration</p> <p>2017-01-01</p> <p>I will discuss new reverberation mapping results that allow us to investigate the temperature structure of <span class="hlt">AGN</span> accretion disks. By measuring time-delays between broad-band continuum light curves, we can determine the size of the disk as a function of wavelength. I will discuss the detection of continuum lags in NGC 5548 reported by the <span class="hlt">AGN</span> STORM project and implications for the accretion disk. I will also present evidence for continuum lags in two other <span class="hlt">AGN</span> for which we recently measured black hole masses from continuum-Hbeta reverberations. The mass measurements allow us to compare the continuum lags to predictions from standard thin disk theory, and our results indicate that the accretion disks are larger than the simplest expectations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016agnt.confE..39P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016agnt.confE..39P"><span>Probing <span class="hlt">AGN</span> Accretion History Through X-Ray Variability</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Paolillo, Maurizio; Papadakis, I.; Brandt, W. N.; Xue, Y. Q.; Luo, B.; Tozzi, P.; Shemmer, O.; Allevato, V.; Bauer, F.; Koekemoer, A.; Vignali, C.; Vito, F.; Yang, G.; Wang, J. X.; Zheng, X.</p> <p>2016-10-01</p> <p>I will present recent results on <span class="hlt">AGN</span> variability in the CDFS survey. Using over 10 years of X-ray monitoring and comparison with local <span class="hlt">AGNs</span> we are able to constrain the variability dependence on BH mass and accreton rate, and use it to trace the accretion hisory of the <span class="hlt">AGN</span> population up to z=3.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016agnt.confE..10B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016agnt.confE..10B"><span><span class="hlt">AGN</span> Host Galaxy Properties And Mass Function</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bongiorno, Angela</p> <p>2016-10-01</p> <p>Supermassive black hole growth, nuclear activity, and galaxy evolution have been found to be closely related. In the context of <span class="hlt">AGN</span>-galaxy coevolution, I will discuss about the relation found between the host galaxy properties and the central BH and I will present the latest determination of the host galaxy stellar mass function (HGMF), and the specific accretion rate distribution function (SARDF), derived from the XMM-COSMOS sample up to z˜2.5, with particular focus on <span class="hlt">AGN</span> feedback as possible responsible mechanism for galaxy quenching.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010ATel.2725....1D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010ATel.2725....1D"><span>PS1-1000305 an <span class="hlt">AGN</span> outburst?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Drake, A. J.; Mahabal, A. A.; Djorgovski, S. G.; Graham, M. J.; Williams, R.; Prieto, J.; Catelan, M.; Christensen, E.; Beshore, E. C.; Larson, S. M.</p> <p>2010-07-01</p> <p>Kankare et al. (2010, ATel#2716) recently reported the discovery of an <span class="hlt">AGN</span> outburst (PS1-1000305) detected in PS1 taken data on May 19.3 UT. The redshift of the <span class="hlt">AGN</span> is given by Kankare et al. as z=0.77 with the host galaxy SDSS J152844.16+425722.5. We have extracted the five year archival CSS/CRTS lightcurve at the location of <a href='http://nesssi.cacr.caltech.edu/catalina/20010706/107061430624100001p.html'>PS1-1000305</a>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016agnt.confE..48G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016agnt.confE..48G"><span>Multi-Frequency View Of Jetted <span class="hlt">AGN</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Giroletti, Marcello; Orienti, M.; D'Ammando, F.; Lico, R.; Giovannini, G.:</p> <p>2016-10-01</p> <p>I will present a review on the context and the most recent results about radio loud <span class="hlt">AGNs</span> as seen in different parts of the electromagnetic spectrum, with an eye also to multi-messenger astrophysics and neutrinos in particular. I will focus on various topics of interest about RL <span class="hlt">AGNs</span>, such as: the study of the physics of relativistic jets and particle acceleration, in particular through VLBI and gamma ray observations; the feedback to the host galaxy and on galaxy cluster scales; the possibility to probe distant and obscured environments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014IAUS..304..307D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014IAUS..304..307D"><span>Revealing <span class="hlt">AGN</span>, young and old stellar populations in HzRGs with PEGASE.3</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Drouart, Guillaume; De Breuck, Carlos; Vernet, Joël; Volmerange, Brigitte Rocca; Seymour, Nicholas</p> <p>2014-07-01</p> <p>The HeRGÉ (Herschel Radio Galaxy Evolution) project consists of a sample of 70 radio galaxies in the range 1 < z < 5.2. They benefit from continuous coverage from 3 to 870μm with Spitzer, Herschel and sub-mm ground-based instruments (SCUBA, LABOCA). As a calorimeter, IR is an excellent proxy to estimate the contribution of both <span class="hlt">AGN</span> and starburst, making of radio galaxies perfect candidates to provide new insights into the relationship between <span class="hlt">AGN</span> and their host galaxies. The IR SED fitting with empirical templates reveals that radio galaxies are luminous and that their black holes and their host galaxies are not growing simultaneously. Extending the SED to optical/near-IR on a subsample of 12 radio galaxies spanning 1 < z < 4 reveal the necessity of three components to reproduce the observations. Making use of the evolutionary code PEGASE.3 and an <span class="hlt">AGN</span> torus <span class="hlt">model</span>, we are able to estimate parameters from the <span class="hlt">AGN</span> torus, the evolved stellar population and the starburst (SB). They reveal that radio galaxies are massive, evolved, forming the bulk of their mass at very high redshift in a short timescale, but experience episodic, strong SB events, often associated with an <span class="hlt">AGN</span> activity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AAS...22934734G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AAS...22934734G"><span>Correlating The Star Formation Histories Of MaNGA Galaxies With Their Past <span class="hlt">AGN</span> Activity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gonzalez Ortiz, Andrea</p> <p>2017-01-01</p> <p>We investigate active galactic nuclei (<span class="hlt">AGN</span>) as a primary mechanism affecting star formation in MaNGA galaxies. Using the Pipe3D code, we <span class="hlt">modeled</span> the stellar population from MaNGA spectra and derived the star formation histories of 53 <span class="hlt">AGN</span> host galaxies. We seek to compare the star formation histories of the host galaxies of <span class="hlt">AGN</span> with the ages of their radio lobes to better understand the role of <span class="hlt">AGN</span> feedback in the star formation histories of MaNGA galaxies. MaNGA (Mapping Nearby Galaxies at APO) is one of the three core programs in the fourth generation Sloan Digital Sky Survey(SDSS). MaNGA will investigate the internal kinematics of nearly 10,000 local galaxies through dithered observations using fiber integral field units (IFUs) that vary in diameter from 12" (19 fibers) to 32" (127 fibers). In this poster, we present initial results on the star formation histories of MaNGA <span class="hlt">AGN</span> host galaxies. This work was supported by the SDSS Research Experience for Undergraduates program, which is funded by a grant from Sloan Foundation to the Astrophysical Research Consortium.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016agnw.confE..84T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016agnw.confE..84T"><span>Disks and cones: interferometry of the dusty and molecular material of <span class="hlt">AGN</span> on parsec sales</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tristam, Konrad R. W.</p> <p>2016-08-01</p> <p>The central engine of Active Galactic Nuclei (<span class="hlt">AGN</span>) is surrounded by dense molecular and dusty material on parsec scales. Typically referred to as the ""dusty torus"", this material is a key ingredient of <span class="hlt">AGN</span> because it (1) provides the angle dependent obscuration of the central engine and (2) most likely plays an important role for the accretion of the material onto the supermassive black hole. Observations using interferometry in the infrared have, in the last ten years, resolved and characterised the thermal emission from the dust heated by the <span class="hlt">AGN</span> beyond simple fits of the spectral energy distribution, leading to a great leap forward in our view of the dusty material surrounding <span class="hlt">AGN</span>. In general the torus is parsec-sized, with a large scatter in extension between individual objects. Our studies have led to the surprising discovery that the dust emission is clearly separated into two distinct components: an inner disk-like emission region which is surrounded by a polar elongated emitter. I will demonstrate these discoveries using the results obtained for the Circinus galaxy, and discuss how the results for this galaxy compare to other well studied sources. While putting strong constraints on torus <span class="hlt">models</span>, our findings are in good qualitative agreement with recent hydrodynamic simulations of <span class="hlt">AGN</span> tori. The next big step forward can be expected from sub-mm interferometry and I will give a short glimpse at the results from our recent ALMA observations of the outer torus in the Circinus galaxy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20216357','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20216357"><span>Polarimetry and <span class="hlt">Unification</span> of Low-Redshift Radio Galaxies</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Cohen, Marshall H.; Ogle, Patrick M.; Tran, Hien D.; Goodrich, Robert W.; Miller, Joseph S.</p> <p>1999-11-01</p> <p>We have made high-quality measurements of the polarization spectra of 13 FR II radio galaxies and taken polarization images for 11 of these with the Keck telescopes. Seven of the eight narrow-line radio galaxies (NLRGs) are polarized, and six of the seven show prominent broad Balmer lines in polarized light. The broad lines are also weakly visible in total flux. Some of the NLRGs show bipolar regions with roughly circumferential polarization vectors, revealing a large reflection nebula illuminated by a central source. Our observations powerfully support the hidden quasar hypothesis for some NLRGs. According to this hypothesis, the continuum and broad lines are blocked by a dusty molecular torus, but can be seen by reflected, hence polarized, light. Classification as a NLRG, a broad-line radio galaxy (BLRG), or a quasar therefore depends on orientation. However, not all objects fit into this <span class="hlt">unification</span> scheme. Our sample is biased toward objects known in advance to be polarized, but the combination of our results with the 1996 findings of Hill, Goodrich, and DePoy show that at least six out of a complete, volume and flux-limited sample of nine FR II NLRGs have broad lines, seen either in polarization or P{alpha}.The BLRGs in our sample range from 3C 382, which has a quasar-like spectrum, to the highly reddened IRAS source FSC 2217+259. This reddening sequence suggests a continuous transition from unobscured quasar to reddened BLRG to NLRG. Apparently the obscuring torus does not have a distinct edge. The BLRGs have polarization images that are consistent with a point source broadened by seeing and diluted by starlight. We do not detect extended nebular or scattered emission, perhaps because it is swamped by the nuclear source. Our starlight-corrected BLRG spectra can be explained with a two-component <span class="hlt">model</span>: a quasar viewed through dust and quasar light scattered by dust. The direct flux is more reddened than the scattered flux, causing the polarization to rise</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016bpce.book..499S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016bpce.book..499S"><span>An Adynamical, Graphical Approach to Quantum Gravity and <span class="hlt">Unification</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stuckey, W. M.; Silberstein, Michael; McDevitt, Timothy</p> <p></p> <p>We use graphical field gradients in an adynamical, background independent fashion to propose a new approach to quantum gravity (QG) and <span class="hlt">unification</span>. Our proposed reconciliation of general relativity (GR) and quantum field theory (QFT) is based on a modification of their graphical instantiations, i.e. Regge calculus and lattice gauge theory (LGT), respectively, which we assume are fundamental to their continuum counterparts. Accordingly, the fundamental structure is a graphical amalgam of space, time, and sources (in parlance of QFT) called a "space-time source element". These are fundamental elements of space, time, and sources, not source elements in space and time. The transition amplitude for a space-time source element is computed using a path integral with discrete graphical action. The action for a space-time source element is constructed from a difference matrix K and source vector J on the graph, as in lattice gauge theory. K is constructed from graphical field gradients so that it contains a non-trivial null space and J is then restricted to the row space of K, so that it is divergence-free and represents a conserved exchange of energy-momentum. This construct of K and J represents an adynamical global constraint (AGC) between sources, the space-time metric, and the energy-momentum content of the element, rather than a dynamical law for time-evolved entities. In this view, one manifestation of quantum gravity becomes evident when, for example, a single space-time source element spans adjoining simplices of the Regge calculus graph. Thus, energy conservation for the space-time source element includes contributions to the deficit angles between simplices. This idea is used to correct proper distance in the Einstein-de Sitter (EdS) cosmology <span class="hlt">model</span> yielding a fit of the Union2 Compilation supernova data that matches ΛCDM without having to invoke accelerating expansion or dark energy. A similar modification to LGT results in an adynamical account of quantum</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/14572926','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/14572926"><span>Changing health inequalities in east and west Germany since <span class="hlt">unification</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nolte, Ellen; McKee, Martin</p> <p>2004-01-01</p> <p>The <span class="hlt">unification</span> of Germany in 1990 brought about substantial social and economic changes in its eastern part, with new uncertainties and, despite increasing overall income, rising inequality. This paper explores the potential impact on health of these changes during the 1990s, looking specifically at income-related health inequalities in east and west Germany and its modulation by psychosocial factors. We used data from the German Socio-Economic Panel (GSOEP) for the years 1992 and 1997, including individuals aged 25+. We investigated changes in self-perceived health in the two parts of Germany and its socio-economic and psychosocial determinants. Analyses estimated odds ratios of less than good health using logistic regression. In 1992, 47% of east Germans rated their health worse than good compared with 54% in the west. By 1997, the east-west gap in self-rated health had disappeared, with the prevalence of poor health increasing to 56% in both parts. Income and education were important determinants of health in east and west, with, in the age-sex-adjusted <span class="hlt">model</span>, those having available less than 60% of median equivalent income being at increased risk of poor health in 1992 (OR(east) 2.39, 1.45-3.94; OR(west) 2.04, 1.65-2.52). Addition of education reduced the strength of this relationship only slightly. In the west, income-related health inequalities widened between 1992 and 1997 yet the initially stronger gradient declined in the east, despite an overall increase in income inequality (OR(east) 1.63, 1.04-2.56; OR(west) 2.65, 2.19-3.21). The impact of education remained stable. Psychosocial variables were important determinants, mediating the effects of income, with leisure-cultural social involvement exerting the strongest effect in both east and west.The results show that, unlike in the west, the overall increase in income inequality in east Germany between 1992 and 1997 was not accompanied by a simultaneous increase in income-related health inequalities. This</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009MNRAS.396.1404M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009MNRAS.396.1404M"><span>The spatial distribution of X-ray selected <span class="hlt">AGN</span> in the Chandra deep fields: a theoretical perspective</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marulli, Federico; Bonoli, Silvia; Branchini, Enzo; Gilli, Roberto; Moscardini, Lauro; Springel, Volker</p> <p>2009-07-01</p> <p>We study the spatial distribution of X-ray selected active galactic nuclei (<span class="hlt">AGN</span>) in the framework of hierarchical coevolution of supermassive black holes and their host galaxies and dark matter haloes. To this end, we have applied the theoretical <span class="hlt">model</span> developed by Croton et al., De Lucia & Blaizot and Marulli et al. to the output of the Millennium Run and obtained hundreds of realizations of past light cones from which we have extracted realistic mock <span class="hlt">AGN</span> catalogues that mimic the Chandra deep fields. We find that the <span class="hlt">model</span> <span class="hlt">AGN</span> number counts are in fair agreement with observations both in the soft and in the hard X-ray bands, except at fluxes <~10-15ergcm-2s-1, where the <span class="hlt">model</span> systematically overestimates the observations. However, a large fraction of these faint objects are typically excluded from the spectroscopic <span class="hlt">AGN</span> samples of the Chandra fields. We find that the spatial two-point correlation function predicted by the <span class="hlt">model</span> is well described by a power-law relation out to 20h-1Mpc, in close agreement with observations. Our <span class="hlt">model</span> matches the correlation length r0 of <span class="hlt">AGN</span> in the Chandra Deep Field-North but underestimates it in the Chandra Deep Field-South. When fixing the slope to γ = 1.4, as in Gilli et al., the statistical significance of the mismatch is 2σ-2.5σ, suggesting that the predicted cosmic variance, which dominates the error budget, may not account for the different correlation length of the <span class="hlt">AGN</span> in the two fields. However, the overall mismatch between the <span class="hlt">model</span> and the observed correlation function decreases when both r0 and γ are allowed to vary, suggesting that more realistic <span class="hlt">AGN</span> <span class="hlt">models</span> and a full account of all observational errors may significantly reduce the tension between <span class="hlt">AGN</span> clustering in the two fields. While our results are robust to changes in the <span class="hlt">model</span> prescriptions for the <span class="hlt">AGN</span> light curves, the luminosity dependence of the clustering is sensitive to the different light-curve <span class="hlt">models</span> adopted. However, irrespective of the <span class="hlt">model</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015MNRAS.451.3649J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015MNRAS.451.3649J"><span>High-energy neutrino fluxes from <span class="hlt">AGN</span> populations inferred from X-ray surveys</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jacobsen, Idunn B.; Wu, Kinwah; On, Alvina Y. L.; Saxton, Curtis J.</p> <p>2015-08-01</p> <p>High-energy neutrinos and photons are complementary messengers, probing violent astrophysical processes and structural evolution of the Universe. X-ray and neutrino observations jointly constrain conditions in active galactic nuclei (<span class="hlt">AGN</span>) jets: their baryonic and leptonic contents, and particle production efficiency. Testing two standard neutrino production <span class="hlt">models</span> for local source Cen A (Koers & Tinyakov and Becker & Biermann), we calculate the high-energy neutrino spectra of single <span class="hlt">AGN</span> sources and derive the flux of high-energy neutrinos expected for the current epoch. Assuming that accretion determines both X-rays and particle creation, our parametric scaling relations predict neutrino yield in various <span class="hlt">AGN</span> classes. We derive redshift-dependent number densities of each class, from Chandra and Swift/BAT X-ray luminosity functions (Silverman et al. and Ajello et al.). We integrate the neutrino spectrum expected from the cumulative history of <span class="hlt">AGN</span> (correcting for cosmological and source effects, e.g. jet orientation and beaming). Both emission scenarios yield neutrino fluxes well above limits set by IceCube (by ˜4-106 × at 1 PeV, depending on the assumed jet <span class="hlt">models</span> for neutrino production). This implies that: (i) Cen A might not be a typical neutrino source as commonly assumed; (ii) both neutrino production <span class="hlt">models</span> overestimate the efficiency; (iii) neutrino luminosity scales with accretion power differently among <span class="hlt">AGN</span> classes and hence does not follow X-ray luminosity universally; (iv) some <span class="hlt">AGN</span> are neutrino-quiet (e.g. below a power threshold for neutrino production); (v) neutrino and X-ray emission have different duty cycles (e.g. jets alternate between baryonic and leptonic flows); or (vi) some combination of the above.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5368089','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5368089"><span>Monopoles of SU(15) grand <span class="hlt">unification</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Pal, P.B.</p> <p>1991-03-01</p> <p>In a recently analyzed grand unified <span class="hlt">model</span> based on the gauge group SU(15), monopoles are automatically consistent with the cosmological mass density bound. The Parker bound of monopole flux puts some constaints on the <span class="hlt">model</span> which can be easily satisfied.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009xmm..prop...38H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009xmm..prop...38H"><span>The X-ray nuclei of radio-loud <span class="hlt">AGN</span> from the 2Jy sample</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hardcastle, Martin</p> <p>2009-10-01</p> <p>X-ray observations of <span class="hlt">AGN</span> samples provide crucial information about both the <span class="hlt">AGN</span> themselves and the material that obscures them. Understanding the properties of the active nuclei of radio-loud <span class="hlt">AGN</span> is particularly vital given that these objects seem likely to have a key role in <span class="hlt">models</span> of galaxy formation and evolution. The 2Jy sample of radio galaxies and quasars has uniquely good multiwavelength data, but until recently has been poorly studied in the X-ray. We have recently been awarded time to observe all the low-z 2Jy steep-spectrum sample with Chandra, and here propose short observations of the high-z half of the sample with XMM which will give us a complete picture of the nuclear activity in these objects, and allow a wide range of projects to be carried out.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010xmm..prop...75H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010xmm..prop...75H"><span>The X-ray nuclei of radio-loud <span class="hlt">AGN</span> from the 2Jy sample</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hardcastle, Martin</p> <p>2010-10-01</p> <p>X-ray observations of <span class="hlt">AGN</span> samples provide crucial information about both the <span class="hlt">AGN</span> themselves and the material that obscures them. Understanding the properties of the active nuclei of radio-loud <span class="hlt">AGN</span> is particularly vital given that these objects seem likely to have a key role in <span class="hlt">models</span> of galaxy formation and evolution. The 2Jy sample of radio galaxies and quasars has uniquely good multiwavelength data, but until recently has been poorly studied in the X-ray. We have recently been awarded time to observe all the low-z 2Jy steep-spectrum sample with Chandra, and here propose short observations of the high-z half of the sample with XMM which will give us a complete picture of the nuclear activity in these objects, and allow a wide range of projects to be carried out.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016MNRAS.463.3948D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MNRAS.463.3948D"><span>The HORIZON-<span class="hlt">AGN</span> simulation: morphological diversity of galaxies promoted by <span class="hlt">AGN</span> feedback</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dubois, Yohan; Peirani, Sébastien; Pichon, Christophe; Devriendt, Julien; Gavazzi, Raphaël; Welker, Charlotte; Volonteri, Marta</p> <p>2016-12-01</p> <p>The interplay between cosmic gas accretion on to galaxies and galaxy mergers drives the observed morphological diversity of galaxies. By comparing the state-of-the-art hydrodynamical cosmological simulations HORIZON-<span class="hlt">AGN</span> and HORIZON-NOAGN, we unambiguously identify the critical role of active galactic nuclei (<span class="hlt">AGN</span>) in setting up the correct galaxy morphology for the massive end of the population. With <span class="hlt">AGN</span> feedback, typical kinematic and morpho-metric properties of galaxy populations as well as the galaxy-halo mass relation are in much better agreement with observations. Only <span class="hlt">AGN</span> feedback allows massive galaxies at the centre of groups and clusters to become ellipticals, while without <span class="hlt">AGN</span> feedback those galaxies reform discs. It is the merger-enhanced <span class="hlt">AGN</span> activity that is able to freeze the morphological type of the post-merger remnant by durably quenching its quiescent star formation. Hence morphology is shown to be driven not only by mass but also by the nature of cosmic accretion: at constant galaxy mass, ellipticals are galaxies that are mainly assembled through mergers, while discs are preferentially built from the in situ star formation fed by smooth cosmic gas infall.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=frozen&pg=4&id=EJ851560','ERIC'); return false;" href="http://eric.ed.gov/?q=frozen&pg=4&id=EJ851560"><span>Mabel <span class="hlt">Agnes</span> Elliott, We Hardly Knew You</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>McGonigal, Kathryn; Galliher, John F.</p> <p>2008-01-01</p> <p>Sociologist Mabel <span class="hlt">Agnes</span> Elliott was elected the fourth president of the Society for the Study of Social Problems in 1956-1957 and was the first woman to hold this position. She was an anti-war activist, a feminist and a creative and diligent writer. Yet she experienced many challenges. The Federal Bureau of Investigation kept an active file on…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016agnw.confE..64R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016agnw.confE..64R"><span>What are the galaxies that host MIR-selected <span class="hlt">AGN</span>?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rosario, David</p> <p>2016-08-01</p> <p>Infra-red selection techniques, sensitive to dust strongly heated by an <span class="hlt">AGN</span>, offer a way to identify some of the most obscured accretion events in the Universe. I will describe the results of a comprehensive multi-wavelength study of <span class="hlt">AGN</span> to z>2 selected using Spitzer/IRAC based methods in the COSMOS field. Armed with <span class="hlt">AGN</span>-optimised redshifts and stellar masses, we explore the dust emission from the active nucleus and the host galaxy. We demonstrate that IR-selected <span class="hlt">AGN</span> tend to be found in low mass host galaxies, when compared to other <span class="hlt">AGN</span> identification methods. The star-formation rates of obscured and unobscured IR-selected <span class="hlt">AGN</span> are very similar, implying that large-scale obscuration with co-eval star-bursts are not found in a major proportion of heavily obscured <span class="hlt">AGN</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22521599','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22521599"><span>THE GLOBAL IMPLICATIONS OF THE HARD EXCESS. II. ANALYSIS OF THE LOCAL POPULATION OF RADIO-QUIET <span class="hlt">AGNs</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Tatum, M. M.; Turner, T. J.; Reeves, J. N.; DiLiello, J.; Gofford, J.; Miller, L.; Clayton, M.; Patrick, A.</p> <p>2016-02-10</p> <p>Active galactic nuclei (<span class="hlt">AGNs</span>) show evidence for reprocessing gas, outflowing from the accreting black hole. The combined effects of absorption and scattering from the circumnuclear material likely explain the “hard excess” of X-ray emission above 20 keV, compared with the extrapolation of spectra from lower X-ray energies. In a recent Suzaku study, we established that the ubiquitous hard excess in hard, X-ray-selected, radio-quiet type 1 <span class="hlt">AGNs</span> is consistent with a reprocessing of the X-ray continuum in an ensemble of clouds, located tens to hundreds of gravitational radii from the nuclear black hole. Here we add hard X-ray-selected, type 2 <span class="hlt">AGNs</span> to extend our original study and show that the gross X-ray spectral properties of the entire local population of radio-quiet <span class="hlt">AGNs</span> may be described by a simple unified scheme. We find a broad, continuous distribution of spectral hardness ratio and Fe Kα equivalent width across all <span class="hlt">AGN</span> types, which can be reproduced by varying the observer's sightline through a single, simple <span class="hlt">model</span> cloud ensemble, provided that the radiative transfer through the <span class="hlt">model</span> cloud distribution includes not only photoelectric absorption but also three-dimensional (3D) Compton scattering. Variation in other parameters of the cloud distribution, such as column density or ionization, should be expected between <span class="hlt">AGNs</span>, but such variation is not required to explain the gross X-ray spectral properties.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013IAUS..290..295P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013IAUS..290..295P"><span><span class="hlt">AGN</span>-host galaxy connection: multiwavelength study</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pović, M.; Sánchez-Portal, M.; García, A. M. Pérez; Bongiovanni, A.; Cepa, J.; Cepa</p> <p>2013-02-01</p> <p>The connection between active galactic nuclei (<span class="hlt">AGN</span>) and their hosts showed to be important for understanding the formation and evolution of active galaxies. Using X-ray and deep optical data, we study how morphology and colours are related to X-ray properties at redshifts z<=2.0 for a sample of > 300 X-ray detected <span class="hlt">AGN</span> in the Subaru/XMM-Newton Deep Survey (SXDS; Furusawa et al. 2008) and Groth-Westphal Strip (GWS; Pović et al. 2009) fields. We performed our morphological classification using the galSVM code (Huertas-Company et al. 2008), which is a new method that is particularly suited when dealing with high-redshift sources. To separate objects between X-ray unobscured and obscured, we used X-ray hardness ratio HR(0.5-2 keV/2-4.5 keV). Colour-magnitude diagrams were studied in relationship to redshift, morphology, X-ray obscuration, and X-ray-to-optical flux ratio. Around 50% of X-ray detected <span class="hlt">AGN</span> at z<=2.0 analysed in this work reside in spheroidal and bulge-dominated galaxies, while at least 18% have disk-dominated hosts. This suggests that different mechanisms may be responsible for triggering the nuclear activity. When analysing populations of X-ray detected <span class="hlt">AGN</span> in both colour-magnitude (CMD) and colour-stellar mass diagrams (Figure 1), the highest number of sources is found to reside in the green valley at redshifts ~ 0.5-1.5. For the first time we studied CMD of these <span class="hlt">AGN</span> in relation to morphology and X-ray obscuration, finding that they can reside in both early- and late-type hosts, where both morphological types cover similar ranges of X-ray obscuration (Figure 1). Our findings appear to confirm some previous suggestions that X-ray selected <span class="hlt">AGN</span> residing in the green valley represent a transitional population (e.g. Nandra et al. 2007, Silverman et al. 2008, Treister et al. 2009), quenching star formation by means of different <span class="hlt">AGN</span> feedback mechanisms and evolving to red-sequence galaxies. More details on analysis and results presented here can be found in</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016agnw.confE..49C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016agnw.confE..49C"><span>AGNfitter: An MCMC Approach to Fitting SEDs of <span class="hlt">AGN</span> and galaxies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Calistro Rivera, Gabriela; Lusso, Elisabeta; Hennawi, Joseph; Hogg, David W.</p> <p>2016-08-01</p> <p>I will present AGNfitter: a tool to robustly disentangle the physical processes responsible for the emission of active galactic nuclei (<span class="hlt">AGN</span>). AGNfitter is the first open-source algorithm based on a Markov Chain Monte Carlo method to fit the spectral energy distributions of <span class="hlt">AGN</span> from the sub-mm to the UV. The code makes use of a large library of theoretical, empirical, and semi-empirical <span class="hlt">models</span> to characterize both the host galaxy and the nuclear emission simultaneously. The <span class="hlt">model</span> consists in four physical components comprising stellar populations, cold dust distributions in star forming regions, accretion disk, and hot dust torus emissions. AGNfitter is well suited to infer numerous parameters that rule the physics of <span class="hlt">AGN</span> with a proper handling of their confidence levels through the sampling and assumptions-free calculation of their posterior probability distributions. The resulting parameters are, among many others, accretion disk luminosities, dust attenuation for both galaxy and accretion disk, stellar masses and star formation rates. We describe the relevance of this fitting machinery, the technicalities of the code, and show its capabilities in the context of unobscured and obscured <span class="hlt">AGN</span>. The analyzed data comprehend a sample of 714 X-ray selected <span class="hlt">AGN</span> of the XMM-COSMOS survey, spectroscopically classified as Type1 and Type2 sources by their optical emission lines. The inference of variate independent obscuration parameters allows AGNfitter to find a classification strategy with great agreement with the spectroscopical classification for ˜ 86% and ˜ 70% for the Type1 and Type2 <span class="hlt">AGNs</span> respectively. The variety and large number of physical properties inferred by AGNfitter has the potential of contributing to a wide scope of science-cases related to both active and quiescent galaxies studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AAS...22543204S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AAS...22543204S"><span>A spectral energy distribution analysis of <span class="hlt">AGN</span> host galaxies in the Chandra-COSMOS Legacy Survey</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Suh, Hyewon; Civano, Francesca M.; Hasinger, Guenther; Elvis, Martin; Marchesi, Stefano</p> <p>2015-01-01</p> <p>We present the host galaxy properties of a large sample of ~ 4000 X-ray selected Active Galactic Nuclei (<span class="hlt">AGN</span>) in the Chandra COSMOS Legacy Survey to investigate the connection between BH accretion and host galaxy. The COSMOS Legacy survey reaching X-ray fluxes of 2x10-16 (cgs) in the 0.5-2 keV band, bridges the gap between large area shallow surveys and pencil beamed one. Making use of the existing multi-wavelength photometric data available for 96.6% of the sources, COSMOS Legacy survey provides a uniquely large sample to derive host galaxy properties for both obscured and unobscured sources. We perform a multi-component <span class="hlt">modeling</span> from far-infrared (500 μm) when available to UV (1500 Å) using a 3-component fitting (nuclear hot dust, galaxy and starburst components) for obscured <span class="hlt">AGN</span> and a 4-component fitting (nuclear hot dust, <span class="hlt">AGN</span> big blue bump, galaxy, and starburst components) for unobscured <span class="hlt">AGN</span>. Galaxy templates are from the stellar population synthesis <span class="hlt">models</span> of Bruzual & Charlot (2003), nuclear hot dust templates are taken from Silva et al. (2004), and <span class="hlt">AGN</span> big blue bump templates are from Richards et al. (2006). We use the column density information measured in the X-ray to constrain the <span class="hlt">AGN</span> in the infrared band when available. Through detailed analysis of the broad-band spectral energy distribution, we derive the stellar masses and the star formation rates of the host galaxy as well as the nuclear and galaxy contribution at each frequency. We study the dependence of host galaxy properties on redshifts, luminosities, and black hole masses to infer the growth history of galaxies and black holes and we compare with a sample of inactive galaxies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MPLA...3250030Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MPLA...3250030Y"><span><span class="hlt">Unification</span> of gravity and quantum field theory from extended noncommutative geometry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yu, Hefu; Ma, Bo-Qiang</p> <p>2017-02-01</p> <p>We make biframe and quaternion extensions on the noncommutative geometry, and construct the biframe spacetime for the <span class="hlt">unification</span> of gravity and quantum field theory (QFT). The extended geometry distinguishes between the ordinary spacetime based on the frame bundle and an extra non-coordinate spacetime based on the biframe bundle constructed by our extensions. The ordinary spacetime frame is globally flat and plays the role as the spacetime frame in which the fields of the Standard <span class="hlt">Model</span> are defined. The non-coordinate frame is locally flat and is the gravity spacetime frame. The field defined in both frames of such “flat” biframe spacetime can be quantized and plays the role as the gravity field which couples with all the fields to connect the gravity effect with the Standard <span class="hlt">Model</span>. Thus, we provide a geometric paradigm in which gravity and QFT can be unified.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ebha.confE..24C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ebha.confE..24C"><span>'Harder when Brighter' Spectral Variability in Low-Luminosity <span class="hlt">AGN</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Connolly, S.; McHardy, I.; Skipper, C.; Dwelly, T.</p> <p>2015-07-01</p> <p>We present X-ray spectral variability of four low accretion rate <span class="hlt">AGN</span> - M81, NGC 1097, NGC 1052 and NGC 3998 - as observed by Swift and RXTE. All four objects were selected due to having spectra which hardened with increasing count rate, converse to the `softer when brighter' behaviour normally observed in <span class="hlt">AGN</span> with higher accretion rates. The spectra were summed in flux bins and fitted with a variety of <span class="hlt">models</span>. A simple absorbed power law <span class="hlt">model</span> was found to fit the spectra of M81, NGC 1097 and NGC 3998 well, whilst NGC 1052 required a partially covered power law <span class="hlt">model</span>. In all four cases, the most likely main source of spectral variability is found to be luminosity-dependent changes in the photon index of the power law component. An anticorrelation between the photon index and the count rate is found in all of the sources. The anticorrelation is likely to be caused by accretion via a radiatively-inefficient accretion flow, expected in low-Eddington ratio systems such as these, and/or due to the presence of a jet. This behaviour is similar to that seen in the `hard state' of X-ray binaries, implying that these LLAGN are in a similar state.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21576889','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21576889"><span>A POWERFUL <span class="hlt">AGN</span> OUTBURST IN RBS 797</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Cavagnolo, K. W.; McNamara, B. R.; Wise, M. W.; Nulsen, P. E. J.; Gitti, M.; Brueggen, M.; Rafferty, D. A.</p> <p>2011-05-10</p> <p>Utilizing {approx}50 ks of Chandra X-Ray Observatory imaging, we present an analysis of the intracluster medium (ICM) and cavity system in the galaxy cluster RBS 797. In addition to the two previously known cavities in the cluster core, the new and deeper X-ray image has revealed additional structure associated with the active galactic nucleus (<span class="hlt">AGN</span>). The surface brightness decrements of the two cavities are unusually large and are consistent with elongated cavities lying close to our line of sight. We estimate a total <span class="hlt">AGN</span> outburst energy and mean jet power of {approx}(3-6) x 10{sup 60} erg and {approx}(3-6) x 10{sup 45} erg s{sup -1}, respectively, depending on the assumed geometrical configuration of the cavities. Thus, RBS 797 is apparently among the most powerful <span class="hlt">AGN</span> outbursts known in a cluster. The average mass accretion rate needed to power the <span class="hlt">AGN</span> by accretion alone is {approx}1 M{sub sun} yr{sup -1}. We show that accretion of cold gas onto the <span class="hlt">AGN</span> at this level is plausible, but that Bondi accretion of the hot atmosphere is probably not. The brightest cluster galaxy (BCG) harbors an unresolved, non-thermal nuclear X-ray source with a bolometric luminosity of {approx}2 x 10{sup 44} erg s{sup -1}. The nuclear emission is probably associated with a rapidly accreting, radiatively inefficient accretion flow. We present tentative evidence that star formation in the BCG is being triggered by the radio jets and suggest that the cavities may be driving weak shocks (M {approx} 1.5) into the ICM, similar to the process in the galaxy cluster MS 0735.6+7421.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006PhDT........22E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006PhDT........22E"><span>Supersymmetry, grand <span class="hlt">unification</span> and flavor symmetry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Enkhbat, Tsedenbaljir</p> <p></p> <p>In this thesis I have presented the findings of my research pursued during my Ph.D. study. The purpose of this thesis was to study different theoretical ideas in high energy physics <span class="hlt">model</span> building addressed primarily towards understanding the fermion mass problem and the gauge hierarchy problem. These include: Anomalous flavor U(1) symmetry and its experimental implications, finite GUT <span class="hlt">models</span> with discrete family symmetry, and a product GUT <span class="hlt">model</span> in a 2D deconstructed theory space. The second and third chapters of the thesis describe our study of lepton flavor violation (LFV) and electric dipole moments (EDM) induced by a flavor-dependent anomalous U(1) gauge symmetry of string origin. The <span class="hlt">models</span> considered also address the fermion mass hierarchy problem successfully. We have shown that the U(1) sector induces significant LFV and EDMs through the SUSY breaking parameters. These effects arise via renormalization group evolution of the parameters in the momentum regime between the string and the anomalous U(1) breaking scale. The fourth chapter of the thesis contains our work on a concrete realization of SUSY breaking using interference between the anomalous U(1) flavor gauge symmetry and a strongly coupled SU(N c), leading to the so called Split SUSY spectrum where the sfermions and the gravitino acquire masses of order 105 ÷ 108 GeV while the gauginos and the Higgsinos have masses of order 102 ÷ 103 GeV. We have calculated the leading order supergravity corrections and have presented a class of explicit <span class="hlt">models</span> of Split SUSY which are phenomenologically consistent. In the fifth chapter I have presented <span class="hlt">models</span> for realistic quark masses and mixings in the context of finite SU(5) GUT wherein the beta functions for the gauge and the Yukawa couplings vanish to all orders in perturbation theory. The <span class="hlt">models</span> presented are based on non-Abelian discrete symmetries. In the case of (Z4)3 x P and A4 symmetries we have found <span class="hlt">models</span> finite to all order of perturbation theory</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21064105','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21064105"><span>Grand <span class="hlt">Unification</span> with and without Supersymmetry</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Melfo, Alejandra</p> <p>2007-06-19</p> <p>Grand Unified Theories based on the group SO(10) generically provide interesting and testable relations between the charged fermions and neutrino sector masses and mixings. In the light of the recent neutrino data, we reexamine these relations both in supersymmetric and non-supersymmetric <span class="hlt">models</span>, and give a brief review of their present status.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2012-01-25/pdf/2012-1405.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2012-01-25/pdf/2012-1405.pdf"><span>77 FR 3787 - Notice of Submission of Proposed Information Collection to OMB; Family <span class="hlt">Unification</span> Program (FUP)</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2012-01-25</p> <p>... URBAN DEVELOPMENT Notice of Submission of Proposed Information Collection to OMB; Family <span class="hlt">Unification</span>... comments on the subject proposal. Application for the Family <span class="hlt">Unification</span> Program: Makes Housing Choice Vouchers available to eligible families to promote family reunification. Youths 18 to 21 who left...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/102325','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/102325"><span>Supergravity grand <span class="hlt">unification</span>, proton decay and cosmological constraints</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Arnowitt, R. |; Nath, P.</p> <p>1995-05-01</p> <p>Properties and experimental predictions of a broad class of supergravity grand unified <span class="hlt">models</span> possessing an SU(5)-type proton decay and R parity are described. <span class="hlt">Models</span> of this type can be described in terms of four parameters at the Gut scale in addition to those of the Standard <span class="hlt">Model</span> i.e. m{sub 0} (universal scalar mass), m{sub 1/2} (universal gaugino mass), A{sub 0} (cubic soft breaking parameter) and tan {beta} = <H{sub 2}>/<H{sub 1}>. Thus the 32 SUSY masses can be expressed in terms of m{sub 0}, M{sub 1/2}, A{sub 0} tan {beta} and the as yet unknown t-quark mass M{sub t}. Gut thresholds are examined and a simple <span class="hlt">model</span> leads to grand <span class="hlt">unification</span> consistent with p-decay data when 0.114 < {alpha}{sub 3}(M{sub z}) < 0.135, in agreement with current values of {alpha}{sub 3}(M{sub Z}). Proton decay is examined for the superheavy Higgs triplet mass H{sub H3} < 10M{sub G}(M{sub G} {approx_equal} 1.5 {times} 10{sup 16} GeV) and squarks and gluinos lighter than 1 TeV. Throughout most of the parameter space chargino-neutralino scaling relations are predicted to hold: 2m{sub {anti Z}}{sub 1} {congruent} m{sub {anti W}}{sub 1} {congruent} m{sub {anti Z}}{sub 2}, m{sub {anti W}}{sub 1} {approx_equal} (1/4)m{sub {anti g}} (for {mu} > 0) or m{sub {anti W}}{sub 1} {approx_equal} (1/3)m{sub {anti g}} (for {mu} < 0), while m{sub {anti W}}{sub 2} {congruent} m{sub {anti Z}}{sub 3} {congruent} m{sub {anti Z}}{sub 4} {much_gt} m{sub {anti Z}}{sub 1}. Future proton decay experiments combined with LEP2 lead to further predictions, e.g. for the entire parameter space either proton decay should be seen at these or the {anti W}{sub 1} seen at LEP2. Relic density constraints on the {anti Z}{sub 1} further constrain the parameter space e.g. so that m{sub t} < 165 GeV, M{sub h} < 105 GeV, m{sub {anti W}}{sub 1} < 100 GeV and m{sub {anti Z}}{sub 1} < 50 GeV when M{sub H}{sub 3}/M{sub G} < 6.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19740021432','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19740021432"><span>Global parallel <span class="hlt">unification</span> for large question-answering systems</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Auguston, J. G.; Minker, J.</p> <p>1974-01-01</p> <p>An efficient means of storing data in a first-order predicate calculus theorem-proving system is described. The data structure is oriented for large scale question-answering (QA) systems. An algorithm is outlined which uses the data structure to unify a given literal in parallel against all literals in all clauses in the data base. The data structure permits a compact representation of data within a QA system. Some suggestions are made for heuristics which can be used to speed-up the <span class="hlt">unification</span> algorithm in systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015IAUGA..2256886K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015IAUGA..2256886K"><span>The SRG/eROSITA All-Sky Survey: A new era of large-scale structure studies with <span class="hlt">AGN</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kolodzig, Alexander; Gilfanov, Marat; Hütsi, Gert; Sunyaev, Rashid</p> <p>2015-08-01</p> <p>The four-year X-ray All-Sky Survey (eRASS) of the eROSITA telescope aboard the Spektrum-Roentgen-Gamma (SRG) satellite will detect about 3 million active galactic nuclei (<span class="hlt">AGN</span>) with a median redshift of z~1 and typical luminosity of L0.5-2.0keV ~ 1044 erg/s. We demonstrate that this unprecedented <span class="hlt">AGN</span> sample, complemented with redshift information, will supply us with outstanding opportunities for large-scale structure (LSS) studies.We show that with this sample of X-ray selected <span class="hlt">AGN</span>, it will become possible for the first time to perform detailed redshift- and luminosity-resolved studies of the <span class="hlt">AGN</span> clustering. This enable us to put strong constraints on different <span class="hlt">AGN</span> triggering/fueling <span class="hlt">models</span> as a function of <span class="hlt">AGN</span> environment, which will dramatically improve our understanding of super-massive black hole growth and its correlation with the co-evolving LSS.Further, the eRASS <span class="hlt">AGN</span> sample will become a powerful cosmological probe. We demonstrate for the first time that, given the breadth and depth of eRASS, it will become possible to convincingly detect baryonic acoustic oscillations (BAOs) with ~8σ confidence in the 0.8 < z < 2.0 range, currently uncovered by any existing BAO survey.Finally, we discuss the requirements for follow-up missions and demonstrate that in order to fully exploit the potential of the eRASS <span class="hlt">AGN</span> sample, photometric and spectroscopic surveys of large areas and a sufficient depth will be needed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016agnw.confE.105V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016agnw.confE.105V"><span>Multi-wavelength properties and SMBH's masses of the isolated <span class="hlt">AGNs</span> in the Local Universe</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vavilova, I. B.; Vasylenko, A. A.; Babyk, Iu. V.; Pulatova, N. G.</p> <p>2016-08-01</p> <p>The sample of 36 nearest isolated <span class="hlt">AGNs</span> was cross-matched by 2MIG and Veron-Cetty catalogues and limited to Ks ≤ 12.0m and Vr < 15 000 km/s in the northern sky (δ ≥ -15°). These objects were in isolation during ~ 3 Gyrs. For revealing their multi-wavelength properties we used all the available databases obtained with ground-based and space observatories (from radio to X-ray ranges). It is allowed us to separate the internal evolution mechanisms from the environment influence and consider them as two separate processes related to fueling nuclear activity and accretion on the SMBHs outside of the environment. In this report we present briefly main results, which were already published (Pulatova N., Vavilova I., Sawangwit U. et al. The 2MIG isolated <span class="hlt">AGNs</span> - I. General and multiwavelength properties of <span class="hlt">AGNs</span> and host galaxies in the northern sky, MNRAS, 447, Issue 3, p. 2209-2223 (2015)). We accentuate that for the first time we revealed that the host isolated galaxies with <span class="hlt">AGNs</span> of Sy1 type (without faint companions) appear to possess the bar morphological features (e.g., the interaction with neighboring galaxies is not necessary condition for broad-line region formation). We give also current results as concerns with more detail X-ray analysis, emission features and spectral <span class="hlt">models</span> for several <span class="hlt">AGNs</span> for which a cumulative soft and hard energy spectrum was reconstructed. The estimates of SMBH masses show that are systematically lower than the SMBH masses of <span class="hlt">AGNs</span> located in a dense environment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20130013386','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20130013386"><span>On the Star Formation-<span class="hlt">AGN</span> Connection at zeta (is) approximately greater than 0.3</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>LaMassa, Stephanie M.; Heckman, T. M.; Ptak, Andrew; Urry, C. Megan</p> <p>2013-01-01</p> <p>Using the spectra of a sample of approximately 28,000 nearby obscured active galaxies from Data Release 7 of the Sloan Digital Sky Survey (SDSS), we probe the connection between active galactic nucleus (<span class="hlt">AGN</span>) activity and star formation over a range of radial scales in the host galaxy. We use the extinction-corrected luminosity of the [O iii] 5007A line as a proxy of intrinsic <span class="hlt">AGN</span> power and supermassive black hole (SMBH) accretion rate. The star formation rates (SFRs) are taken from the MPA-JHU value-added catalog and are measured through the 3 inch SDSS aperture. We construct matched samples of galaxies covering a range in redshifts. With increasing redshift, the projected aperture size encompasses increasing amounts of the host galaxy. This allows us to trace the radial distribution of star formation as a function of <span class="hlt">AGN</span> luminosity. We find that the star formation becomes more centrally concentrated with increasing <span class="hlt">AGN</span> luminosity and Eddington ratio. This implies that such circumnuclear star formation is associated with <span class="hlt">AGN</span> activity, and that it increasingly dominates over omnipresent disk star formation at higher <span class="hlt">AGN</span> luminosities, placing critical constraints on theoretical <span class="hlt">models</span> that link host galaxy star formation and SMBH fueling. We parameterize this relationship and find that the star formation on radial scales (is) less than 1.7 kpc, when including a constant disk component, has a sub-linear dependence on SMBH accretion rate: SFR in proportion to solar mass(sup 0.36), suggesting that angular momentum transfer through the disk limits accretion efficiency rather than the supply from stellar mass loss.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22130842','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22130842"><span>ON THE STAR FORMATION-<span class="hlt">AGN</span> CONNECTION AT z {approx}< 0.3</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>LaMassa, Stephanie M.; Urry, C. Megan; Heckman, T. M.; Ptak, A.</p> <p>2013-03-10</p> <p>Using the spectra of a sample of {approx}28,000 nearby obscured active galaxies from Data Release 7 of the Sloan Digital Sky Survey (SDSS), we probe the connection between active galactic nucleus (<span class="hlt">AGN</span>) activity and star formation over a range of radial scales in the host galaxy. We use the extinction-corrected luminosity of the [O III] 5007 A line as a proxy of intrinsic <span class="hlt">AGN</span> power and supermassive black hole (SMBH) accretion rate. The star formation rates (SFRs) are taken from the MPA-JHU value-added catalog and are measured through the 3'' SDSS aperture. We construct matched samples of galaxies covering a range in redshifts. With increasing redshift, the projected aperture size encompasses increasing amounts of the host galaxy. This allows us to trace the radial distribution of star formation as a function of <span class="hlt">AGN</span> luminosity. We find that the star formation becomes more centrally concentrated with increasing <span class="hlt">AGN</span> luminosity and Eddington ratio. This implies that such circumnuclear star formation is associated with <span class="hlt">AGN</span> activity, and that it increasingly dominates over omnipresent disk star formation at higher <span class="hlt">AGN</span> luminosities, placing critical constraints on theoretical <span class="hlt">models</span> that link host galaxy star formation and SMBH fueling. We parameterize this relationship and find that the star formation on radial scales <1.7 kpc, when including a constant disk component, has a sub-linear dependence on SMBH accretion rate: SFR{proportional_to} M-dot {sup 0.36}, suggesting that angular momentum transfer through the disk limits accretion efficiency rather than the supply from stellar mass loss.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AAS...22925051B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AAS...22925051B"><span>Tracing the Far-Infrared Roles of <span class="hlt">AGN</span> in Dusty Star-Forming Galaxies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brown, Arianna; Nayyeri, Hooshang; Cooray, Asantha R.; Mitchell-Wynne, Ketron</p> <p>2017-01-01</p> <p>Active galactic nuclei (<span class="hlt">AGNs</span>) are suggested to play an important role in quenching their host galaxy’s star formation rate (SFR) by heating up and/or consuming the cool gas necessary to create stars. This mechanism is theorized as a critical step in <span class="hlt">AGN</span> evolutionary <span class="hlt">models</span>. The efforts to study this effect suffer in part from low-number statistics at high x-ray luminosities (LXR > 1044 ergs/s) for <span class="hlt">AGNs</span> at z≈1-3, and a lack of separately estimated SFRs for <span class="hlt">AGN</span> in dusty, star-forming galaxies (DSFGs). In this work, we extend our analysis to build a more complete picture using the variety of available multi-wavelength data in the XBoötes region. The Chandra XBoötes Survey is a 5-ks X-ray survey of the 9.3 square degree Boötes Field of the NOAO Deep Wide-Field Survey, a survey imaged from the optical to the near-IR. We estimate <span class="hlt">AGN</span> spectral energy distributions and SFRs for ~400 x-ray sources using available data in all four Spitzer IRAC bands, the Spitzer MIPS 24µm band, all five Herschel SPIRE and PACS bands, along with NEWFIRM optical bands. Preliminary results show an exponential correlation between x-ray luminosity and star formation. As a comparison, we will use a stacking technique for the ~500 x-ray sources that were not detected at submillimeter wavelengths, where sources are binned by x-ray luminosity. We will compare these two samples and expect to see a difference in slope. Using these techniques, we hope to place tighter constraints on the mean SFRs of high-luminosity <span class="hlt">AGNs</span> inside DSFGs, and determine if x-ray luminosities are independent of average SFRs for our sample in the Boötes field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApJ...835..250K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApJ...835..250K"><span>A Method to Measure the Unbiased Decorrelation Timescale of the <span class="hlt">AGN</span> Variable Signal from Structure Functions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kozłowski, Szymon</p> <p>2017-02-01</p> <p>A simple, <span class="hlt">model</span>-independent method to quantify the stochastic variability of active galactic nuclei (<span class="hlt">AGNs</span>) is the structure function (SF) analysis. If the SF for the timescales shorter than the decorrelation timescale τ is a single power law and for the longer ones becomes flat (i.e., white noise), then the auto-correlation function (ACF) of the signal can have the form of the power exponential (PE). We show that the signal decorrelation timescale can be measured directly from the SF as the timescale matching the amplitude 0.795 of the flat SF part (at long timescales), and only then is the measurement independent of the ACF PE power. Typically, the timescale has been measured at an arbitrarily fixed SF amplitude, but as we prove, this approach provides biased results, because the <span class="hlt">AGN</span> SF/power spectral density slopes, and thus the ACF shape, are not constant and depend on either the <span class="hlt">AGN</span> luminosity and/or the black hole mass. In particular, we show that using such a method for the simulated SFs that includes a combination of empirically known dependencies between the <span class="hlt">AGN</span> luminosity L and both the SF amplitude and the PE power, and having no intrinsic τ–L dependence, produces a fake τ \\propto {L}κ relation with 0.3≲ κ ≲ 0.6, which otherwise is expected from theoretical works (κ \\equiv 0.5). Our method provides an alternative means for analyzing <span class="hlt">AGN</span> variability to the standard SF fitting. The caveats, for both methods, are that the light curves must be sufficiently long (with a several year rest frame) and the ensemble SF assumes <span class="hlt">AGNs</span> to have the same underlying variability process.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JHEP...01..023D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JHEP...01..023D"><span>D = 3 <span class="hlt">unification</span> of curious supergravities</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Duff, M. J.; Ferrara, S.; Marrani, A.</p> <p>2017-01-01</p> <p>We consider the dimensional reduction to D = 3 of four maximal-rank super-gravities which preserve minimal supersymmetry in D = 11, 7, 5 and 4. Such " curious" theories were investigated some time ago, and the four-dimensional one corresponds to an N=1 supergravity with 7 chiral multiplets spanning the seven-disk manifold. Recently, this latter theory provided cosmological <span class="hlt">models</span> for α-attractors, which are based on the disk geometry with possible restrictions on the parameter α. A unified picture emerges in D = 3, where the Ehlers group of General Relativity merges with the S-, T- and U-dualities of the D = 4 parent theories.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016agnw.confE..42S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016agnw.confE..42S"><span><span class="hlt">AGN</span> flickering on 10-100 kyr timescales</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sartori, Lia F.; Schawinski, Kevin; Kill, Bill; Maksym, Peter; Koss, Michael; Argo, Megan; Urry, Meg; Wong, Ivy; Lintott, Chris</p> <p>2016-08-01</p> <p>The study of <span class="hlt">AGN</span> variability on timescales of 10^4-10^5 years is important in order to understand the BH - host galaxy interaction and coevolution. The discovery of "Hanny's Voorwerp" (HV), an extended emission line region associated with the nearby galaxy IC 2497, provided us with a laboratory to study <span class="hlt">AGN</span> variability over such timescales. HV was illuminated by a strong quasar in IC 2497, but this quasar significantly shut down in the last 200 kyrs. Thanks to its recent shutdown we can now explore the host galaxy unimpeded by the presence of a quasar dominating the observations, while the Voorwerp preserves the echoes of its past activity. Recent studies on the optical properties of hard X-ray selected <span class="hlt">AGN</span> suggest that <span class="hlt">AGN</span> may flicker on and off hundreds or thousands times with each burst lasting ~10^5 yrs. Systems similar to IC 2497 and HV, the so-called Voorwerpjes, allow us to constrain the last stages of the <span class="hlt">AGN</span> lifecycle. On the other hand, we recently suggested that the switch on phase may be observed in the so-called optically elusive <span class="hlt">AGN</span>. In this talk I will review both observational evidence and results from simulation work which support this picture, and explain how optically elusive <span class="hlt">AGN</span> and Voorwerpjes galaxies can help us to understand different phases of the <span class="hlt">AGN</span> lifecycle. Moreover, I will discuss possible implications for <span class="hlt">AGN</span> feedback, BH - host galaxy coevolution, and the analogy between <span class="hlt">AGN</span> and X-ray binaries accretion physics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20100014805&hterms=Black+bear&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DBlack%2Bbear','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20100014805&hterms=Black+bear&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DBlack%2Bbear"><span>Active Galaxy <span class="hlt">Unification</span> in the Era of X-Ray Polarimetry</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Dorodnitsyn, A.; Kallman, T.</p> <p>2010-01-01</p> <p>Active galactic nuclei (<span class="hlt">AGNs</span>), Seyfert galaxies, and quasars are powered by luminous accretion and often accompanied by winds that are powerful enough to affect the <span class="hlt">AGN</span> mass budget, and whose observational appearance bears an imprint of processes that are happening within the central parsec around the black hole (BH). One example of such a wind is the partially ionized gas responsible for X-ray and UV absorption (warm absorbers). Here, we show that such gas will have a distinct signature when viewed in polarized X-rays. Observations of such polarization can test <span class="hlt">models</span> for the geometry of the flow and the gas responsible for launching and collimating it. We present calculations that show that the polarization depends on the hydrodynamics of the flow, the quantum mechanics of resonance-line scattering, and the transfer of polarized X-ray light in the highly ionized moving gas. The results emphasize the three-dimensional nature of the wind for <span class="hlt">modeling</span> spectra. We show that the polarization in the 0.1-10 keV energy range is dominated by the effects of resonance lines. We predict a 5%-25% X-ray polarization signature of type-2 objects in this energy range. These results are generalized to flows that originate from a cold torus-like structure, located approximately 1 pc from the BH, which wraps the BH and is ultimately responsible for the apparent dichotomy between type 1 and type 2 <span class="hlt">AGNs</span>. Such signals will be detectable by future dedicated X-ray polarimetry space missions, such as the NASA Gravity and Extreme Magnetism Small Explorer SMEX, "GEMS" Swank et al. (2008).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21305098','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21305098"><span>ACTIVE GALAXY <span class="hlt">UNIFICATION</span> IN THE ERA OF X-RAY POLARIMETRY</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Dorodnitsyn, A.; Kallman, T.</p> <p>2010-03-10</p> <p>Active galactic nuclei (<span class="hlt">AGNs</span>), Seyfert galaxies, and quasars are powered by luminous accretion and often accompanied by winds that are powerful enough to affect the <span class="hlt">AGN</span> mass budget, and whose observational appearance bears an imprint of processes that are happening within the central parsec around the black hole (BH). One example of such a wind is the partially ionized gas responsible for X-ray and UV absorption (warm absorbers). Here, we show that such gas will have a distinct signature when viewed in polarized X-rays. Observations of such polarization can test <span class="hlt">models</span> for the geometry of the flow and the gas responsible for launching and collimating it. We present calculations that show that the polarization depends on the hydrodynamics of the flow, the quantum mechanics of resonance-line scattering, and the transfer of polarized X-ray light in the highly ionized moving gas. The results emphasize the three-dimensional nature of the wind for <span class="hlt">modeling</span> spectra. We show that the polarization in the 0.1-10 keV energy range is dominated by the effects of resonance lines. We predict a 5%-25% X-ray polarization signature of type-2 objects in this energy range. These results are generalized to flows that originate from a cold torus-like structure, located {approx}1 pc from the BH, which wraps the BH and is ultimately responsible for the apparent dichotomy between type 1 and type 2 <span class="hlt">AGNs</span>. Such signals will be detectable by future dedicated X-ray polarimetry space missions, such as the NASA Gravity and Extreme Magnetism Small Explorer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AIPC.1467....7M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AIPC.1467....7M"><span>Gauged flavor, supersymmetry and grand <span class="hlt">unification</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mohapatra, Rabindra N.</p> <p>2012-07-01</p> <p>I review a recent work on gauged flavor with left-right symmetry, where all masses and all Yukawa couplings owe their origin to spontaneous flavor symmetry breaking. This is suggested as a precursor to a full understanding of flavor of quarks and leptons. An essential ingredient of this approach is the existence of heavy vector-like fermions, which is the home of flavor, which subsequently gets transmitted to the familiar quarks and leptons via the seesaw mechanism. I then discuss implications of extending this idea to include supersymmetry and finally speculate on a possible grand unified <span class="hlt">model</span> based on the gauge group SU(5)L×SU(5)R which provides a group theoretic origin for the vector-like fermions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15601146','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15601146"><span>Warped <span class="hlt">unification</span>, proton stability, and dark matter.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Agashe, Kaustubh; Servant, Géraldine</p> <p>2004-12-03</p> <p>We show that solving the problem of baryon-number violation in nonsupersymmetric grand unified theories (GUT's) in warped higher-dimensional spacetime can lead to a stable Kaluza-Klein particle. This exotic particle has gauge quantum numbers of a right-handed neutrino, but carries fractional baryon number and is related to the top quark within the higher-dimensional GUT. A combination of baryon number and SU(3) color ensures its stability. Its relic density can easily be of the right value for masses in the 10 GeV-few TeV range. An exciting aspect of these <span class="hlt">models</span> is that the entire parameter space will be tested at near future dark matter direct detection experiments. Other exotic GUT partners of the top quark are also light and can be produced at high energy colliders with distinctive signatures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGeod..90...45A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGeod..90...45A"><span>The GBVP approach for vertical datum <span class="hlt">unification</span>: recent results in North America</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Amjadiparvar, B.; Rangelova, E.; Sideris, M. G.</p> <p>2016-01-01</p> <p>Two levelling-based vertical datums have been used in North America, namely CGVD28 in Canada and NAVD88 in the USA and Mexico. Although the two datums will be replaced by a common and continent-wide vertical datum in a few years, their connection and <span class="hlt">unification</span> are of great interest to the scientific and user communities. In this paper, the geodetic boundary value problem (GBVP) approach is studied as a rigorous method for connecting two or more vertical datums through computed datum offsets from a global equipotential surface defined by a GOCE-based geoid. The so-called indirect bias term, the effect of the GOCE geoid omission error, the effect of the systematic levelling datum errors and distortions, and the effect of the geodetic data errors on the datum <span class="hlt">unification</span> are four important factors affecting the practical implementation of this approach. These factors are investigated numerically using the GNSS-levelling and tide gauge stations in Canada, the USA, Alaska, and Mexico. The results show that the indirect bias term can be omitted if a GOCE-based global geopotential <span class="hlt">model</span> is used in gravimetric geoid computations. The omission of the indirect bias term simplifies the linear system of equations for the estimation of the datum offset(s). Because of the existing systematic levelling errors and distortions in the Canadian and US levelling networks, the datum offsets are investigated in eight smaller regions along the Canadian and US coastal areas. Using GNSS-levelling stations in the US coastal regions, the mean datum offset can be estimated with a 1 cm standard deviation if the GOCE geoid omission error is taken into account by means of the local gravity and topographic information. In the Canadian Atlantic and Pacific regions, the datum offsets can be estimated with 2.3 and 3.5 cm standard deviation, respectively, using GNSS-levelling stations. However, due to the low number of tide gauge stations, the standard deviation of the CGVD28 and NAVD88 datum</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21567680','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21567680"><span>THE BULK OF THE BLACK HOLE GROWTH SINCE z {approx} 1 OCCURS IN A SECULAR UNIVERSE: NO MAJOR MERGER-<span class="hlt">AGN</span> CONNECTION</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Cisternas, Mauricio; Jahnke, Knud; Inskip, Katherine J.; Robaina, Aday R.; Andrae, Rene; Kartaltepe, Jeyhan; Koekemoer, Anton M.; Lisker, Thorsten; Scodeggio, Marco; Sheth, Kartik; Capak, Peter; Trump, Jonathan R.; Impey, Chris D.; Miyaji, Takamitsu; Lusso, Elisabeta; Brusa, Marcella; Cappelluti, Nico; Civano, Francesca; Ilbert, Olivier; Leauthaud, Alexie</p> <p>2011-01-10</p> <p>What is the relevance of major mergers and interactions as triggering mechanisms for active galactic nuclei (<span class="hlt">AGNs</span>) activity? To answer this long-standing question, we analyze 140 XMM-Newton-selected <span class="hlt">AGN</span> host galaxies and a matched control sample of 1264 inactive galaxies over z {approx} 0.3-1.0 and M{sub *} < 10{sup 11.7} M{sub sun} with high-resolution Hubble Space Telescope/Advanced Camera for Surveys imaging from the COSMOS field. The visual analysis of their morphologies by 10 independent human classifiers yields a measure of the fraction of distorted morphologies in the <span class="hlt">AGN</span> and control samples, i.e., quantifying the signature of recent mergers which might potentially be responsible for fueling/triggering the <span class="hlt">AGN</span>. We find that (1) the vast majority (>85%) of the <span class="hlt">AGN</span> host galaxies do not show strong distortions and (2) there is no significant difference in the distortion fractions between active and inactive galaxies. Our findings provide the best direct evidence that, since z {approx} 1, the bulk of black hole (BH) accretion has not been triggered by major galaxy mergers, therefore arguing that the alternative mechanisms, i.e., internal secular processes and minor interactions, are the leading triggers for the episodes of major BH growth. We also exclude an alternative interpretation of our results: a substantial time lag between merging and the observability of the <span class="hlt">AGN</span> phase could wash out the most significant merging signatures, explaining the lack of enhancement of strong distortions on the <span class="hlt">AGN</span> hosts. We show that this alternative scenario is unlikely due to (1) recent major mergers being ruled out for the majority of sources due to the high fraction of disk-hosted <span class="hlt">AGNs</span>, (2) the lack of a significant X-ray signal in merging inactive galaxies as a signature of a potential buried <span class="hlt">AGN</span>, and (3) the low levels of soft X-ray obscuration for <span class="hlt">AGNs</span> hosted by interacting galaxies, in contrast to <span class="hlt">model</span> predictions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016A%26A...592A..46C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016A%26A...592A..46C"><span>The effect of <span class="hlt">AGN</span> feedback on the X-ray morphologies of clusters: Simulations vs. observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chon, Gayoung; Puchwein, Ewald; Böhringer, Hans</p> <p>2016-07-01</p> <p>Clusters of galaxies probe the large-scale distribution of matter and are a useful tool to test the cosmological <span class="hlt">models</span> by constraining cosmic structure growth and the expansion of the Universe. It is the scaling relations between mass observables and the true mass of a cluster through which we obtain the cosmological constraints by comparing to theoretical cluster mass functions. These scaling relations are, however, heavily influenced by cluster morphology. The presence of the slight tension in recent cosmological constraints on Ωm and σ8 based on the CMB and clusters has boosted the interests in looking for possible sources for the discrepancy. Therefore we study here the effect of active galactic nucleus (<span class="hlt">AGN</span>) feedback as one of the major mechanisms modifying the cluster morphology influencing scaling relations. It is known that <span class="hlt">AGN</span> feedback injects energies up to 1062 erg into the intracluster medium, controls the heating and cooling of a cluster, and re-distributes cold gas from the centre to outer radii. We have also learned that cluster simulations with <span class="hlt">AGN</span> feedback can reproduce observed cluster properties, for example, the X-ray luminosity, temperature, and cooling rate at the centre better than without the <span class="hlt">AGN</span> feedback. In this paper using cosmological hydrodynamical simulations we investigate how the <span class="hlt">AGN</span> feedback changes the X-ray morphology of the simulated systems, and compare this to the observed Representative XMM-Newton Cluster Structure Survey (REXCESS) clusters. We apply two substructure measures, centre shifts (w) and power ratios (e.g. P3/P0), to characterise the cluster morphology, and find that our simulated clusters are more substructured than the observed clusters based on the values of w and P3/P0. We also show that the degree of this discrepancy is affected by the inclusion of <span class="hlt">AGN</span> feedback. While the clusters simulated with the <span class="hlt">AGN</span> feedback are in much better agreement with the REXCESS LX-T relation, they are also more substructured</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009JHEP...10..059G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009JHEP...10..059G"><span>Viable and testable SUSY GUTs with Yukawa <span class="hlt">unification</span>: the case of split trilinears</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Guadagnoli, Diego; Raby, Stuart; Straub, David M.</p> <p>2009-10-01</p> <p>We explore general SUSY GUT <span class="hlt">models</span> with exact third-generation Yukawa <span class="hlt">unification</span>, but where the requirement of universal soft terms at the GUT scale is relaxed. We consider the scenario in which the breaking of universality inherits from the Yukawa couplings, i.e. is of minimal flavor violating (MFV) type. In particular, the MFV principle allows for a splitting between the up-type and the down-type soft trilinear couplings. We explore the viability of this trilinear splitting scenario by means of a fitting procedure to electroweak observables, quark masses as well as flavor-changing neutral current processes. Phenomenological viability singles out one main scenario. This scenario is characterized by a sizable splitting between the trilinear soft terms and a large μ term. Remarkably, this scenario does not invoke a partial decoupling of the sparticle spectrum, as in the case of universal soft terms, but instead it requires part of the spectrum, notably the lightest stop, the gluino and the lightest charginos and neutralinos to be very close to the current experimental limits. The above mechanism is mostly triggered by a non-trivial interplay between the requirements of negative, sizable SUSY threshold corrections to mb and an instead negligible modification of the B → Xsγ decay rate, in presence of various other constraints, most notably a successful EWSB and a not too large BR(Bs → μ+μ-). We present a <span class="hlt">model</span>-building interpretation of our discussed scenario and emphasize the crucial role of SUSY spectrum determinations at the LHC for either falsifying Yukawa <span class="hlt">unification</span> or else providing important hints on the mechanism of SUSY breaking at work.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvD..94i5001H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvD..94i5001H"><span>Quasi-Yukawa <span class="hlt">unification</span> and fine-tuning in U(1) extended SSM</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hiçyılmaz, Yaşar; Ceylan, Meltem; Altaş, Aslı; Solmaz, Levent; Ün, Cem Salih</p> <p>2016-11-01</p> <p>We consider the low scale implications in the U(1 ) ' extended minimal supersymmetric Standard <span class="hlt">Model</span> (UMSSM). We restrict the parameter space such that the lightest supersymmetric particle (LSP) is always the lightest neutralino. In addition, we impose quasi-Yukawa <span class="hlt">unification</span> (QYU) at the grand <span class="hlt">unification</span> scale (MGUT). QYU strictly requires the ratios among the Yukawa couplings as yt/yb˜1.2 , yτ/yb˜1.4 , and yt/yτ˜0.8 . We find that the need for fine-tuning over the fundamental parameter space of QYU is in the acceptable range (ΔEW≤1 03), even if the universal boundary conditions are imposed at MGUT, in contrast to CMSSM and nonuniversal Higgs masses. The UMSSM with universal boundary conditions yields heavy stops (mt ˜≳2.5 TeV ), gluinos (mg ˜≳2 TeV ), and squarks from the first two families (mq ˜≳4 TeV ). Similarly, the stau mass is bounded from below at about 1.5 TeV. Despite this heavy spectrum, we find ΔEW≳300 , which is much lower than that needed for the minimal supersymmetric <span class="hlt">models</span>. In addition, the UMSSM yields a relatively small μ term, and the LSP neutralino is mostly formed by the Higgsinos of mass ≳700 GeV . We also obtain bino-like dark matter of mass about 400 GeV. The wino is usually found to be heavier than Higgsinos and binos, but there is a small region where μ ˜M1˜M2˜1 TeV . We also identify a chargino-neutralino coannihilation channel and A -resonance solutions which reduce the relic abundance of LSP neutralinos down to the ranges compatible with the current WMAP and Planck measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010APS..APR.M1027S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010APS..APR.M1027S"><span><span class="hlt">Unification</span> of Einstein's Gravity with Quantum Chromodynamics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sarfatti, Jack</p> <p>2010-02-01</p> <p>The four tetrad and six spin-connection Cartan 1-forms of Einstein's GeoMetroDynamic (GMD) field emerge from the eight virtual gluon macro-quantum coherent QCD post-inflation vacuum condensates that form in the inflationary phase transition. This joint emergence of gravity and the strong force is similar to the emergence of irrotational superflow with vortex defects in liquid helium below the Lambda Point. Repulsive dark energy is from the residual random virtual bosons that did not cohere in the moment of inflation. Similarly, attractive dark matter is from the residual random virtual fermion-antifermion pairs. Therefore, I predict that the LHC will not detect any on-mass-shell real particles that can explain φDM˜0.23. As first suggested by Abdus Salam (f-gravity) the low energy tail of the nuclear force can be explained as strong short-range Yukawa gravity. QCD's IR confinement and UV asymptotic freedom are elementary consequences in this simple <span class="hlt">model</span>. )</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21129589','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21129589"><span>[Laboratory <span class="hlt">unification</span>: advantages and disadvantages for clinical microbiology].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Andreu, Antonia; Matas, Lurdes</p> <p>2010-10-01</p> <p>This article aims to reflect on which areas or tasks of microbiology laboratories could be unified with those of clinical biochemistry, hematology, immunology or pathology laboratories to benefit patients and the health system, as well as the areas that should remain independent since their amalgamation would not only fail to provide a benefit but could even jeopardize the quality of microbiological diagnosis, and consequently patient care. To do this, the distinct analytic phases of diagnosis are analyzed, and the advantages and disadvantages of amalgamation are evaluated in each phase. The pros and cons of the <span class="hlt">unification</span> of certain areas such as the computer system, occupational risk units, customer service, purchasing logistics, and materials storage, etc, are also discussed. Lastly, the effect of <span class="hlt">unification</span> on urgent microbiology diagnosis is analyzed. Microbiological diagnosis should be unique. The microbiologist should perform an overall evaluation of the distinct techniques used for a particular patient, both those that involve direct diagnosis (staining, culture, antigen detection techniques or molecular techniques) and indirect diagnosis (antibody detection). Moreover, the microbiology laboratory should be independent, with highly trained technicians and specialists in microbiology that provide added value as experts in infection and as key figures in the process of establishing a correct etiological diagnosis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003GReGr..35.2217B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003GReGr..35.2217B"><span>A Dynamical <span class="hlt">Unification</span> Scheme from General Conservation Laws</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Basini, Giuseppe; Capozziello, Salvatore</p> <p>2003-12-01</p> <p>The aim of this work is to present an <span class="hlt">unification</span> scheme of fundamental interactions based on a well defined dynamics, the non-introduction of ad hoc hypotheses and the consideration of the minimal necessary number of free parameters and dimensions. A dynamical <span class="hlt">unification</span> scheme of fundamental interactions can be achieved assuming a 5D space where conservation laws are always and absolutely valid, i.e. never violated. This approach gives rise to an induced-matter theory in the usual 4D space-time through a process of embedding and dimensional reduction by which masses, spins and charges of particles naturally spring out, and also the the hierarchy problem can be successfully faced thanks to the mass spectrum. The emergence of asymptotic freedom also for gravitational interaction, the existence of two time arrows together with the possibility of closed time-like paths are intrinsic results of such a theory, leading to a recovering of the causality principle and to a formal, dynamical explanation of several paradoxes and questioning problems of modern physics e.g. entanglement of EPR-type quantum states, quantum teleportation, gamma ray bursts origin, black hole singularities and cosmic primary antimatter absence.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1984RpEEE.......30M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1984RpEEE.......30M"><span>Establishment and use of time <span class="hlt">unification</span> system for civil aviation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Malyy, M. M.</p> <p>1984-11-01</p> <p>Precise and fail proof operation of the various services used by civil aviation throughout the territory of the USSR depends largely on synchronization, the latter requiring periodic indication of time scales and involving the concept of time <span class="hlt">unification</span>. The principal users of a time <span class="hlt">unification</span> system are the traffic control service and the flight crew. Since 1974 electromechanical hand-and-dial clocks in airports have been gradually replaced with modern signal clocks. Installation of secondary clocks in control towers, time encoding in the secondary clocks, and interfacing the clock room with the computer of the appropriate automatic control system are improvements made in the control tower. Time indicating and time keeping equipment is also installed in airplanes for tie-in with airports by means of radio signals over metric wave or decametric-wave communication channels. The necessary short range radio navigation system with the inclusion of satellites for transmittal of unified time information from airports to airplanes and equipment characterized by satisfactory technical accuracy and high stability with means for automatic or semiautomatic time correction guaranteeing high reliability for a period of 10 years is produced.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApJ...832..163S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApJ...832..163S"><span>Radio Properties of the BAT <span class="hlt">AGNs</span>: the FIR-radio Relation, the Fundamental Plane, and the Main Sequence of Star Formation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Smith, Krista Lynne; Mushotzky, Richard F.; Vogel, Stuart; Shimizu, Thomas T.; Miller, Neal</p> <p>2016-12-01</p> <p>We conducted 22 GHz 1″ JVLA imaging of 70 radio-quiet active galactic nuclei (<span class="hlt">AGNs</span>) from the Swift-BAT survey. We find radio cores in all but three objects. The radio morphologies of the sample fall into three groups: compact and core-dominated, extended, and jet-like. We spatially decompose each image into core flux and extended flux, and compare the extended radio emission with that predicted from previous Herschel observations using the canonical FIR-radio relation. After removing the <span class="hlt">AGN</span> contribution to the FIR and radio flux densities, we find that the relation holds remarkably well despite the potentially different star formation physics in the circumnuclear environment. We also compare our core radio flux densities with predictions of coronal <span class="hlt">models</span> and scale-invariant jet <span class="hlt">models</span> for the origin of radio emission in radio-quiet <span class="hlt">AGNs</span>, and find general consistency with both <span class="hlt">models</span>. However, we find that the L R/L X relation does not distinguish between star formation and non-relativistic <span class="hlt">AGN</span>-driven outflows as the origin of radio emission in radio-quiet <span class="hlt">AGNs</span>. Finally, we examine where objects with different radio morphologies fall in relation to the main sequence (MS) of star formation, and conclude that those <span class="hlt">AGNs</span> that fall below the MS, as X-ray selected <span class="hlt">AGNs</span> have been found to do, have core-dominated or jet-like 22 GHz morphologies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/919788','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/919788"><span><span class="hlt">AGN</span>-Induced Cavities in NGC 1399 And NGC 4649</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Shurkin, K.; Dunn, R.J.H.; Gentile, G.; Taylor, G.B.; Allen, S.W.; /KIPAC, Menlo Park</p> <p>2007-11-14</p> <p>We present an analysis of archival Chandra and VLA observations of the E0 galaxy NGC1399 and the E2 galaxy NGC4649 in which we investigate cavities in the surrounding X-ray emitting medium caused by the central <span class="hlt">AGN</span>. We calculate the jet power required for the <span class="hlt">AGN</span> to evacuate these cavities and find values of {approx} 8x10{sup 41} erg s-1 and {approx} 14x10{sup 41} erg s{sup -1} for the lobes of NGC1399 and {approx} 7x10{sup 41} erg s{sup -1} and {approx} 6x1041 erg s{sup -1} for those of NGC4649. We also calculate the k/f values for each cavity, where k is the ratio of the total particle energy to that of electrons radiating in the range of 10 MHz to 10 GHz, and f is the volume filling factor of the plasma in the cavity. We find that the values of k/f for the lobes of NGC1399 are {approx} 93 and {approx} 190, and those of the lobes of NGC4649 are {approx} 15000 and {approx} 12000. We conclude that the assumed spectrum describes the electron distribution in the lobes of NGC1399 reasonably well, and that there are few entrained particles. For NGC4649, either there are many entrained particles or the <span class="hlt">model</span> spectrum does not accurately describe the population of electrons.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016HEAD...1510103G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016HEAD...1510103G"><span><span class="hlt">AGN</span> feedback in the Perseus cluster</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gendron-Marsolais, Marie-Lou; Hlavacek-Larrondo, Julie; Clarke, Tracy E.; Intema, Huib; Fabian, Andrew C.; Taylor, Gregory B.; Blundell, Katherine</p> <p>2016-04-01</p> <p>Deep Chandra images of the Perseus cluster of galaxies have revealed a succession of cavities created by the jets of the central supermassive black hole, pushing away the X-ray emitting gas and leaving bubbles filled with radio emission. Perseus is one of the rare examples showing buoyantly rising lobes from past radio outbursts, characterized by a steep spectral index and known as ghost cavities. All of these structures trace the complete history of mechanical <span class="hlt">AGN</span> feedback over the past 500 Myrs. I will present results on new, ultra deep 230-470 MHz JVLA data. This low-frequency view of the Perseus cluster will probe the old radio-emitting electron population and will allow us to build the most detailed map of <span class="hlt">AGN</span> feedback in a cluster thus far.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22133982','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22133982"><span>DOES SIZE MATTER? THE UNDERLYING INTRINSIC SIZE DISTRIBUTION OF RADIO SOURCES AND IMPLICATIONS FOR <span class="hlt">UNIFICATION</span> BY ORIENTATION</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>DiPompeo, M. A.; Runnoe, J. C.; Myers, A. D.; Boroson, T. A.</p> <p>2013-09-01</p> <p><span class="hlt">Unification</span> by orientation is a ubiquitous concept in the study of active galactic nuclei. A gold standard of the orientation paradigm is the hypothesis that radio galaxies and radio-loud quasars are intrinsically the same, but are observed over different ranges of viewing angles. Historically, strong support for this <span class="hlt">model</span> was provided by the projected sizes of radio structure in luminous radio galaxies, which were found to be significantly larger than those of quasars, as predicted due to simple geometric projection. Recently, this test of the simplest prediction of orientation-based <span class="hlt">models</span> has been revisited with larger samples that cover wider ranges of fundamental properties-and no clear difference in projected sizes of radio structure is found. Cast solely in terms of viewing angle effects, these results provide convincing evidence that <span class="hlt">unification</span> of these objects solely through orientation fails. However, it is possible that conflicting results regarding the role orientation plays in our view of radio sources simply result from insufficient sampling of their intrinsic size distribution. We test this possibility using Monte Carlo simulations constrained by real sample sizes and properties. We develop <span class="hlt">models</span> for the real intrinsic size distribution of radio sources, simulate observations by randomly sampling intrinsic sizes and viewing angles, and analyze how likely each sample is to support or dispute <span class="hlt">unification</span> by orientation. We find that, while it is possible to reconcile conflicting results purely within a simple, orientation-based framework, it is very unlikely. We analyze the effects that sample size, relative numbers of radio galaxies and quasars, the critical angle that separates the two subclasses, and the shape of the intrinsic size distribution have on this type of test.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20150023330&hterms=alpha+ray&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dalpha%2Bray','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20150023330&hterms=alpha+ray&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dalpha%2Bray"><span>Delving into X-Ray Obscuration of Type 2 <span class="hlt">AGN</span>, Near and Far</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lamassa, Stephanie M.; Yaqoob, Tahir; Ptak, Andrew F.; Jia, Jianjun; Heckman, Timothy M.; Gandhi, Poshak; Urry, C. Meg</p> <p>2014-01-01</p> <p>Using self-consistent, physically motivated <span class="hlt">models</span>, we investigate the X-ray obscuration in 19 Type 2 [O iii] 5007Å selected active galactic nuclei (<span class="hlt">AGNs</span>), 9 of which are local Seyfert 2 galaxies and 10 of which are Type 2 quasar candidates. We derive reliable line-of-sight and global column densities for these objects, which is the first time this has been reported for an <span class="hlt">AGN</span> sample; four <span class="hlt">AGNs</span> have significantly different global and line-of-sight column densities. Five sources are heavily obscured to Compton-thick. We comment on interesting sources revealed by our spectral <span class="hlt">modeling</span>, including a candidate "naked" Sy2. After correcting for absorption, we find that the ratio of the rest-frame, 2-10 keV luminosity (L2-10 keV,in) to L[O iii] is 1.54 +/- 0.49 dex which is essentially identical to the mean Type 1 <span class="hlt">AGN</span> value. The Fe K(alpha) luminosity is significantly correlated with L[O iii] but with substantial scatter. Finally, we do not find a trend between L2-10 keV,in and global or line-of-sight column density, between column density and redshift, between column density and scattering fraction, or between scattering fraction and redshift. Key words: galaxies: active - galaxies: Seyfert - X-rays: general</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016MNRAS.457..496Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MNRAS.457..496Z"><span>A simple way to improve <span class="hlt">AGN</span> feedback prescription in SPH simulations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zubovas, Kastytis; Bourne, Martin A.; Nayakshin, Sergei</p> <p>2016-03-01</p> <p>Active galactic nuclei (<span class="hlt">AGN</span>) feedback is an important ingredient in galaxy evolution, however its treatment in numerical simulations is necessarily approximate, requiring subgrid prescriptions due to the dynamical range involved in the calculations. We present a suite of smoothed particle hydrodynamics simulations designed to showcase the importance of the choice of a particular subgrid prescription for <span class="hlt">AGN</span> feedback. We concentrate on two approaches to treating wide-angle <span class="hlt">AGN</span> outflows: thermal feedback, where thermal and kinetic energy is injected into the gas surrounding the supermassive black hole (SMBH) particle, and virtual particle feedback, where energy is carried by tracer particles radially away from the <span class="hlt">AGN</span>. We show that the latter <span class="hlt">model</span> produces a far more complex structure around the SMBH, which we argue is a more physically correct outcome. We suggest a simple improvement to the thermal feedback <span class="hlt">model</span> - injecting the energy into a cone, rather than spherically symmetrically - and show that this markedly improves the agreement between the two prescriptions, without requiring any noticeable increase in the computational cost of the simulation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApJ...835..175G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApJ...835..175G"><span>The Effect of <span class="hlt">AGN</span> Heating on the Low-redshift Lyα Forest</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gurvich, Alex; Burkhart, Blakesley; Bird, Simeon</p> <p>2017-02-01</p> <p>We investigate the effects of <span class="hlt">AGN</span> heating and the ultraviolet background on the low-redshift Lyα forest column density distribution (CDD) using the Illustris simulation. We show that Illustris reproduces observations at z = 0.1 in the column density range {10}12.5{--}{10}13.5 cm‑2, relevant for the “photon underproduction crisis.” We attribute this to the inclusion of <span class="hlt">AGN</span> feedback, which changes the gas distribution so as to mimic the effect of extra photons, as well as the use of the Faucher-Giguère ultraviolet background, which is more ionizing at z = 0.1 than the Haardt & Madau background previously considered. We show that the difference between simulations run with smoothed particle hydrodynamics and simulations using a moving mesh is small in this column density range but can be more significant at larger column densities. We further consider the effect of supernova feedback, Voigt profile fitting, and finite resolution, all of which we show to have little influence on the CDD. Finally, we identify a discrepancy between our simulations and observations at column densities {10}14{--}{10}16 cm‑2, where Illustris produces too few absorbers, which suggests the <span class="hlt">AGN</span> feedback <span class="hlt">model</span> should be further refined. Since the “photon underproduction crisis” primarily affects lower column density systems, we conclude that <span class="hlt">AGN</span> feedback and standard ionizing background <span class="hlt">models</span> can resolve the crisis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110012808','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110012808"><span>Complete Hard X-Ray Surveys, <span class="hlt">AGN</span> Luminosity Functions and the X-Ray Background</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tueller, Jack</p> <p>2011-01-01</p> <p><span class="hlt">AGN</span> are believed to make up most of the Cosmic X-Ray Background (CXB) above a few keV, but this background cannot be fully resolved at energies less than 10 keV due to absorption. The Swift/BAT and INTEGRAL missions are performing the first complete hard x-ray surveys with minimal bias due to absorption. The most recent results for both missions will be presented. Although the fraction of the CXB resolved by these surveys is small, it is possible to derive unbiased number counts and luminosity functions for <span class="hlt">AGN</span> in the local universe. The survey energy range from 15-150 keV contains the important reflection and cutoff spectral features dominate the shape of the <span class="hlt">AGN</span> contribution to the CXB. Average spectral characteristics of survey detected <span class="hlt">AGN</span> will be presented and compared with <span class="hlt">model</span> distributions. The numbers of hard x-ray blazars detected in these surveys are finally sufficient to estimate this important component's contribution the cosmic background. Constraints on CXB <span class="hlt">models</span> and their significance will be discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22356826','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22356826"><span>Delving into X-ray obscuration of type 2 <span class="hlt">AGN</span>, near and far</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>LaMassa, Stephanie M.; Meg Urry, C.; Yaqoob, Tahir; Ptak, Andrew F.; Gandhi, Poshak</p> <p>2014-05-20</p> <p>Using self-consistent, physically motivated <span class="hlt">models</span>, we investigate the X-ray obscuration in 19 Type 2 [O III] 5007 Å selected active galactic nuclei (<span class="hlt">AGNs</span>), 9 of which are local Seyfert 2 galaxies and 10 of which are Type 2 quasar candidates. We derive reliable line-of-sight and global column densities for these objects, which is the first time this has been reported for an <span class="hlt">AGN</span> sample; four <span class="hlt">AGNs</span> have significantly different global and line-of-sight column densities. Five sources are heavily obscured to Compton-thick. We comment on interesting sources revealed by our spectral <span class="hlt">modeling</span>, including a candidate 'naked' Sy2. After correcting for absorption, we find that the ratio of the rest-frame, 2-10 keV luminosity (L{sub 2-10} {sub keV,} {sub in}) to L{sub [O} {sub III]} is 1.54 ± 0.49 dex which is essentially identical to the mean Type 1 <span class="hlt">AGN</span> value. The Fe Kα luminosity is significantly correlated with L{sub [O} {sub III]} but with substantial scatter. Finally, we do not find a trend between L {sub 2-10keV,} {sub in} and global or line-of-sight column density, between column density and redshift, between column density and scattering fraction, or between scattering fraction and redshift.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22047810','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22047810"><span>AGES: THE <span class="hlt">AGN</span> AND GALAXY EVOLUTION SURVEY</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kochanek, C. S.; Eisenstein, D. J.; Caldwell, N.; Jones, C.; Murray, S. S.; Forman, W. R.; Green, P.; Cool, R. J.; Assef, R. J.; Eisenhardt, P.; Stern, D.; Jannuzi, B. T.; Dey, A.; Brown, M. J. I.; Gonzalez, A. H.</p> <p>2012-05-01</p> <p>The <span class="hlt">AGN</span> and Galaxy Evolution Survey (AGES) is a redshift survey covering, in its standard fields, 7.7 deg{sup 2} of the Booetes field of the NOAO Deep Wide-Field Survey. The final sample consists of 23,745 redshifts. There are well-defined galaxy samples in 10 bands (the B{sub W} , R, I, J, K, IRAC 3.6, 4.5, 5.8, and 8.0 {mu}m, and MIPS 24 {mu}m bands) to a limiting magnitude of I < 20 mag for spectroscopy. For these galaxies, we obtained 18,163 redshifts from a sample of 35,200 galaxies, where random sparse sampling was used to define statistically complete sub-samples in all 10 photometric bands. The median galaxy redshift is 0.31, and 90% of the redshifts are in the range 0.085 < z < 0.66. Active galactic nuclei (<span class="hlt">AGNs</span>) were selected as radio, X-ray, IRAC mid-IR, and MIPS 24 {mu}m sources to fainter limiting magnitudes (I < 22.5 mag for point sources). Redshifts were obtained for 4764 quasars and galaxies with <span class="hlt">AGN</span> signatures, with 2926, 1718, 605, 119, and 13 above redshifts of 0.5, 1, 2, 3, and 4, respectively. We detail all the AGES selection procedures and present the complete spectroscopic redshift catalogs and spectral energy distribution decompositions. Photometric redshift estimates are provided for all sources in the AGES samples.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013MmSAI..84..691C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013MmSAI..84..691C"><span>Ultra-fast outflows (aka UFOs) from <span class="hlt">AGNs</span> and QSOs</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cappi, M.; Tombesi, F.; Giustini, M.</p> <p></p> <p>During the last decade, strong observational evidence has been accumulated for the existence of massive, high velocity winds/outflows (aka Ultra Fast Outflows, UFOs) in nearby <span class="hlt">AGNs</span> and in more distant quasars. Here we briefly review some of the most recent developments in this field and discuss the relevance of UFOs for both understanding the physics of accretion disk winds in <span class="hlt">AGNs</span>, and for quantifying the global amount of <span class="hlt">AGN</span> feedback on the surrounding medium.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007A%26A...472..443B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007A%26A...472..443B"><span>The VVDS type-1 <span class="hlt">AGN</span> sample: the faint end of the luminosity function</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bongiorno, A.; Zamorani, G.; Gavignaud, I.; Marano, B.; Paltani, S.; Mathez, G.; Møller, P.; Picat, J. P.; Cirasuolo, M.; Lamareille, F.; Bottini, D.; Garilli, B.; Le Brun, V.; Le Fèvre, O.; Maccagni, D.; Scaramella, R.; Scodeggio, M.; Tresse, L.; Vettolani, G.; Zanichelli, A.; Adami, C.; Arnouts, S.; Bardelli, S.; Bolzonella, M.; Cappi, A.; Charlot, S.; Ciliegi, P.; Contini, T.; Foucaud, S.; Franzetti, P.; Guzzo, L.; Ilbert, O.; Iovino, A.; McCracken, H. J.; Marinoni, C.; Mazure, A.; Meneux, B.; Merighi, R.; Pellò, R.; Pollo, A.; Pozzetti, L.; Radovich, M.; Zucca, E.; Hatziminaoglou, E.; Polletta, M.; Bondi, M.; Brinchmann, J.; Cucciati, O.; de la Torre, S.; Gregorini, L.; Mellier, Y.; Merluzzi, P.; Temporin, S.; Vergani, D.; Walcher, C. J.</p> <p>2007-09-01</p> <p>In a previous paper (Gavignaud et al. 2006, A&A, 457, 79), we presented the type-1 Active Galactic Nuclei (<span class="hlt">AGN</span>) sample obtained from the first epoch data of the VIMOS-VLT Deep Survey (VVDS). The sample consists of 130 faint, broad-line <span class="hlt">AGN</span> with redshift up to z=5 and 17.5<I_AB<24.0, selected on the basis of their spectra. The sample is thus free of the morphological and color selection biases, that lead to significant incompleteness in the optical surveys of faint <span class="hlt">AGN</span>. In this paper we present the measurement of the Optical Luminosity Function up to z=3.6 derived from this sample, we compare our results with previous results from brighter samples both at low and at high redshift and finally, through the estimate of the bolometric luminosity function, we compare them also with the results from X-ray and mid-IR selected samples. Our data, more than one magnitude fainter than previous optical surveys, allow us to constrain the faint part of the luminosity function up to high redshift. A comparison of our data with the 2dF sample at low redshift (1 < z < 2.1) shows that the VVDS data can not be well fitted with the PLE <span class="hlt">models</span> derived by previous samples. Qualitatively, this appears to be due to the fact that our data suggest the presence of an excess of faint objects at low redshift (1.0<z<1.5) with respect to these <span class="hlt">models</span>. By combining our faint VVDS sample with the large sample of bright <span class="hlt">AGN</span> extracted from the SDSS DR3 (Richards et al. 2006b, AJ, 131, 2766) and testing a number of different evolutionary <span class="hlt">models</span>, we find that the <span class="hlt">model</span> which better represents the combined luminosity functions, over a wide range of redshift and luminosity, is a luminosity dependent density evolution (LDDE) <span class="hlt">model</span>, similar to those derived from the major X-surveys. Such a parameterization allows the redshift of the <span class="hlt">AGN</span> space density peak to change as a function of luminosity and explains the excess of faint <span class="hlt">AGN</span> that we find at 1.0 < z < 1.5. On the basis of this <span class="hlt">model</span> we find, for the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016IAUS..319...59H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016IAUS..319...59H"><span>The Keck OSIRIS Nearby <span class="hlt">AGN</span> (KONA) Survey: <span class="hlt">AGN</span> Fueling and Feedback</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hicks, Erin K. S.; Müller-Sánchez, Francisco; Malkan, Matthew A.; Yu, Po-Chieh</p> <p></p> <p>In an effort to better constrain the relevant physical processes dictating the co-evolution of supermassive black holes and the galaxies in which they reside we turn to local Seyfert <span class="hlt">AGN</span>. It is only with these local <span class="hlt">AGN</span> that we can reach the spatial resolution needed to adequately characterize the inflow and outflow mechanisms thought to be the driving forces in establishing the relationship between black holes and their host galaxies at higher redshift. We present the first results from the KONA (Keck OSIRIS Nearby <span class="hlt">AGN</span>) survey, which takes advantage of the integral field unit OSIRIS plus laser and natural guide star adaptive optics to probe down to scales of 5-30 parsecs in a sample of 40 local Seyfert galaxies. With these K-band data we measure the two-dimensional distribution and kinematics of the nuclear stars, molecular gas, and ionized gas within the central few hundred parsecs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950039751&hterms=wind+exposure&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dwind%2Bexposure','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950039751&hterms=wind+exposure&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dwind%2Bexposure"><span>Disk-driven hydromagnetic winds as a key ingredient of active galactic nuclei <span class="hlt">unification</span> schemes</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Konigl, Arieh; Kartje, John F.</p> <p>1994-01-01</p> <p>Centrifugally driven winds from the surfaces of magnetized accretion disks have been recognized as an attractive mechanism of removing the angular momentum of the accreted matter and of producing the bipolar outflows and jets that are often associated with compact astronomical objects. As previously suggested in the context of young stellar objects, such winds have unique observational manifestations stemming from their highly stratified density and velocity structure and from their exposure to the strong continuum radiation field of the compact object. We have applied this scenario to active galactic nuclei (<span class="hlt">AGNs</span>) and investigated the properties of hydromagnetic outflows that originate within approximately 10(M(sub 8)) pc of the central 10(exp 8)(M(sub 8)) solar mass black hole. On the basis of our results, we propose that hydromagnetic disk-driven winds may underlie the classification of broad-line and narrow-line <span class="hlt">AGNs</span> (e.g., the Seyfert 1/Seyfert 2 dichotomy) as well as the apparent dearth of luminous Seyfert 2 galaxies. More generally, we demonstrate that such winds could strongly influence the spectral characteristics of Seyfert galaxies, QSOs, and BL Lac objects (BLOs). In our picture, the torus is identified with the outer regions of the wind where dust uplifted from the disk surfaces by gas-grain collisions is embedded in the outflow. Using an efficient radiative transfer code, we show that the infrared emission of Seyfert galaxies and QSOs can be attributed to the reprocessing of the UV/soft X-ray <span class="hlt">AGN</span> continuum by the dust in the wind and the disk. We demonstrate that the radiation pressure force flattens the dust distribution in objects with comparatively high (but possibly sub-Eddington) bolometric luminosities, and we propose this as one likely reason for the apparent paucity of narrow-line objects among certain high-luminosity <span class="hlt">AGNs</span>. Using the XSTAR photoionization code, we show that the inner regions of the wind could naturally account for the warm</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApJ...819..111A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApJ...819..111A"><span>Hot Dust Obscured Galaxies with Excess Blue Light: Dual <span class="hlt">AGN</span> or Single <span class="hlt">AGN</span> Under Extreme Conditions?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Assef, R. J.; Walton, D. J.; Brightman, M.; Stern, D.; Alexander, D.; Bauer, F.; Blain, A. W.; Diaz-Santos, T.; Eisenhardt, P. R. M.; Finkelstein, S. L.; Hickox, R. C.; Tsai, C.-W.; Wu, J. W.</p> <p>2016-03-01</p> <p>Hot dust-obscured galaxies (Hot DOGs) are a population of hyper-luminous infrared galaxies identified by the Wide-field Infrared Survey Explorer (WISE) mission from their very red mid-IR colors, and characterized by hot dust temperatures (T > 60 K). Several studies have shown clear evidence that the IR emission in these objects is powered by a highly dust-obscured active galactic nucleus (<span class="hlt">AGN</span>) that shows close to Compton-thick absorption at X-ray wavelengths. Thanks to the high <span class="hlt">AGN</span> obscuration, the host galaxy is easily observable, and has UV/optical colors usually consistent with those of a normal galaxy. Here we discuss a sub-population of eight Hot DOGs that show enhanced rest-frame UV/optical emission. We discuss three scenarios that might explain the excess UV emission: (i) unobscured light leaked from the <span class="hlt">AGN</span> by reflection over the dust or by partial coverage of the accretion disk; (ii) a second unobscured <span class="hlt">AGN</span> in the system; or (iii) a luminous young starburst. X-ray observations can help discriminate between these scenarios. We study in detail the blue excess Hot DOG WISE J020446.13-050640.8, which was serendipitously observed by Chandra/ACIS-I for 174.5 ks. The X-ray spectrum is consistent with a single, hyper-luminous, highly absorbed <span class="hlt">AGN</span>, and is strongly inconsistent with the presence of a secondary unobscured <span class="hlt">AGN</span>. Based on this, we argue that the excess blue emission in this object is most likely either due to reflection or a co-eval starburst. We favor the reflection scenario as the unobscured star formation rate needed to power the UV/optical emission would be ≳1000 M⊙ yr-1. Deep polarimetry observations could confirm the reflection hypothesis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22521443','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22521443"><span>HOT DUST OBSCURED GALAXIES WITH EXCESS BLUE LIGHT: DUAL <span class="hlt">AGN</span> OR SINGLE <span class="hlt">AGN</span> UNDER EXTREME CONDITIONS?</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Assef, R. J.; Diaz-Santos, T.; Walton, D. J.; Brightman, M.; Stern, D.; Eisenhardt, P. R. M.; Tsai, C.-W.; Alexander, D.; Bauer, F.; Blain, A. W.; Finkelstein, S. L.; Hickox, R. C.; Wu, J. W.</p> <p>2016-03-10</p> <p>Hot dust-obscured galaxies (Hot DOGs) are a population of hyper-luminous infrared galaxies identified by the Wide-field Infrared Survey Explorer (WISE) mission from their very red mid-IR colors, and characterized by hot dust temperatures (T > 60 K). Several studies have shown clear evidence that the IR emission in these objects is powered by a highly dust-obscured active galactic nucleus (<span class="hlt">AGN</span>) that shows close to Compton-thick absorption at X-ray wavelengths. Thanks to the high <span class="hlt">AGN</span> obscuration, the host galaxy is easily observable, and has UV/optical colors usually consistent with those of a normal galaxy. Here we discuss a sub-population of eight Hot DOGs that show enhanced rest-frame UV/optical emission. We discuss three scenarios that might explain the excess UV emission: (i) unobscured light leaked from the <span class="hlt">AGN</span> by reflection over the dust or by partial coverage of the accretion disk; (ii) a second unobscured <span class="hlt">AGN</span> in the system; or (iii) a luminous young starburst. X-ray observations can help discriminate between these scenarios. We study in detail the blue excess Hot DOG WISE J020446.13–050640.8, which was serendipitously observed by Chandra/ACIS-I for 174.5 ks. The X-ray spectrum is consistent with a single, hyper-luminous, highly absorbed <span class="hlt">AGN</span>, and is strongly inconsistent with the presence of a secondary unobscured <span class="hlt">AGN</span>. Based on this, we argue that the excess blue emission in this object is most likely either due to reflection or a co-eval starburst. We favor the reflection scenario as the unobscured star formation rate needed to power the UV/optical emission would be ≳1000 M{sub ⊙} yr{sup −1}. Deep polarimetry observations could confirm the reflection hypothesis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AAS...22930701C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AAS...22930701C"><span><span class="hlt">AGN</span> Triggering in Kpc-scale Separation Merging Galaxies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Comerford, Julia M.</p> <p>2017-01-01</p> <p>As supermassive black holes in galaxy mergers evolve from Mpc to mpc separations, the kpc-scale separations are pivotal for igniting <span class="hlt">AGN</span> activity. At these separations the galaxy mergers drive central inflows of gas, which can trigger <span class="hlt">AGN</span> activity in one or both supermassive black holes, in systems known as offset <span class="hlt">AGN</span> and dual <span class="hlt">AGN</span>, respectively. Offset and dual <span class="hlt">AGN</span> are direct tracers of the connection between galaxy mass growth (via galaxy mergers) and supermassive black hole mass growth (via gas accretion). These systems are also the smallest separation supermassive black hole pairs that have been observationally confirmed, offering the last glimpse of supermassive black hole pair dynamics before gravitational wave emission dominates and drives the coalescence of the supermassive black holes. I will present multiwavelength approaches to building catalogs of offset <span class="hlt">AGN</span> and dual <span class="hlt">AGN</span>, and show the results of our observing campaigns with HST, Chandra, VLA, and Keck. Finally, I will discuss what our results show about whether galaxy mergers preferentially fuel the most luminous <span class="hlt">AGN</span>, which supermassive black hole in a merger is more efficient at accreting gas, and where in a merger the <span class="hlt">AGN</span> fueling occurs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012hcxa.confE.127T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012hcxa.confE.127T"><span><span class="hlt">AGN</span> physics - A Chandra-Swift Census of <span class="hlt">AGN</span> activity in Compact Groups</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tzanavaris, Panayiotis</p> <p>2012-09-01</p> <p>We present a missing link in the study of <span class="hlt">AGN</span> activity in compact groups of galaxies. The level of this activity in compact groups remains controversial, but has only been studied with optical and infrared diagnostics. We present the first systematic study of 40 compact group galaxies in 9 groups, combining Chandra and Swift data, and providing the first X-ray/UV view of galactic nuclei in compact groups. Our results provide independent evidence that the level of <span class="hlt">AGN</span> activity in compact groups is representative of their unique environment, which is distinct to that of rich clusters and the field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016MNRAS.457.4195M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MNRAS.457.4195M"><span>The clustering amplitude of X-ray-selected <span class="hlt">AGN</span> at z ˜ 0.8: evidence for a negative dependence on accretion luminosity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mountrichas, G.; Georgakakis, A.; Menzel, M.-L.; Fanidakis, N.; Merloni, A.; Liu, Z.; Salvato, M.; Nandra, K.</p> <p>2016-04-01</p> <p>The northern tile of the wide-area and shallow XMM-XXL X-ray survey field is used to estimate the average dark matter halo mass of relatively luminous X-ray-selected active galactic nucleus (<span class="hlt">AGN</span>) [log {L}_X (2-10 keV)= 43.6^{+0.4}_{-0.4} erg s^{-1}] in the redshift interval z = 0.5-1.2. Spectroscopic follow-up observations of X-ray sources in the XMM-XXL field by the Sloan telescope are combined with the VIMOS Public Extragalactic Redshift Survey spectroscopic galaxy survey to determine the cross-correlation signal between X-ray-selected <span class="hlt">AGN</span> (total of 318) and galaxies (about 20 000). We <span class="hlt">model</span> the large scales (2-25 Mpc) of the correlation function to infer a mean dark matter halo mass of log M / (M_{{⊙}} h^{-1}) = 12.50 ^{+0.22} _{-0.30} for the X-ray-selected <span class="hlt">AGN</span> sample. This measurement is about 0.5 dex lower compared to estimates in the literature of the mean dark matter halo masses of moderate-luminosity X-ray <span class="hlt">AGN</span> [LX(2-10 keV) ≈ 1042-1043 erg s- 1] at similar redshifts. Our analysis also links the mean clustering properties of moderate-luminosity <span class="hlt">AGN</span> with those of powerful ultraviolet/optically selected QSOs, which are typically found in haloes with masses few times 1012 M⊙. There is therefore evidence for a negative luminosity dependence of the <span class="hlt">AGN</span> clustering. This is consistent with suggestions that <span class="hlt">AGN</span> have a broad dark matter halo mass distribution with a high mass tail that becomes subdominant at high accretion luminosities. We further show that our results are in qualitative agreement with semi-analytic <span class="hlt">models</span> of galaxy and <span class="hlt">AGN</span> evolution, which attribute the wide range of dark matter halo masses among the <span class="hlt">AGN</span> population to different triggering mechanisms and/or black hole fuelling modes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20100014856&hterms=Chiral&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DChiral','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20100014856&hterms=Chiral&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DChiral"><span>Poynting Robertson Battery and the Chiral Magnetic Fields of <span class="hlt">AGN</span> Jets</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kazanas, Demosthenes</p> <p>2010-01-01</p> <p>We propose that the magnetic fields in the accretion disks of active galactic nuclei (<span class="hlt">AGNs</span>) are generated by azimuthal electric currents due to the difference between the plasma electron and ion velocities that arises when the electrons are retarded by interactions with the <span class="hlt">AGN</span> photons (the Poynting Robertson battery). This process provides a unique relation between the polarity of the poloidal B field to the angular velocity Omega of the accretion disk (B is parallel to Omega), a relation absent in the more popular dynamo B-field generation. This then leads to a unique direction for the toroidal B field induced by disk rotation. Observations of the toroidal fields of 29 <span class="hlt">AGN</span> jets revealed by parsec-scale Faraday rotation measurements show a clear asymmetry that is consistent with this <span class="hlt">model</span>, with the probability that this asymmetry comes about by chance being approx.0.06 %. This lends support to the hypothesis that the universe is seeded by B fields that are generated in <span class="hlt">AGNs</span> via this mechanism and subsequently injected into intergalactic space by the jet outflows.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015MNRAS.451L..60G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015MNRAS.451L..60G"><span>Shaping the X-ray spectrum of galaxy clusters with <span class="hlt">AGN</span> feedback and turbulence</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gaspari, M.</p> <p>2015-07-01</p> <p>The hot plasma filling galaxy clusters emits copious X-ray radiation. The classic unheated and unperturbed cooling flow <span class="hlt">model</span> predicts dramatic cooling rates and an isobaric X-ray spectrum with constant differential luminosity distribution. The observed cores of clusters (and groups) show instead a strong deficit of soft X-ray emission: dLx/dT ∝ (T/Thot)α = 2 ± 1. Using 3D hydrodynamic simulations, we show that such deficit arises from the tight self-regulation between thermal instability condensation and <span class="hlt">AGN</span> outflow injection: condensing clouds boost the <span class="hlt">AGN</span> outflows, which quench cooling as they thermalize through the core. The resultant average distribution slope is α ≃ 2, oscillating within the observed 1 < α < 3. In the absence of thermal instability, the X-ray spectrum remains isothermal (α ≳ 8), while unopposed cooling drives a too shallow slope, α < 1. <span class="hlt">AGN</span> outflows deposit their energy inside-out, releasing more heat in the inner cooler phase; radially distributed heating alone induces a declining spectrum, 1 < α < 2. Turbulence further steepens the spectrum and increases the scatter: the turbulent Mach number in the hot phase is subsonic, while it becomes transonic in the cooler phase, making perturbations to depart from the isobaric mode. Such increase in dln P/dln T leads to α ≈ 3. Self-regulated <span class="hlt">AGN</span> outflow feedback can address the soft X-ray problem through the interplay of heating and turbulence.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007MNRAS.377.1113T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007MNRAS.377.1113T"><span>Is the dependence of spectral index on luminosity real in optically selected <span class="hlt">AGN</span> samples?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tang, Su Min; Zhang, Shuang Nan; Hopkins, Philip F.</p> <p>2007-05-01</p> <p>We critically examine the dependence of spectral index on luminosity in optically selected <span class="hlt">AGN</span> samples. An analysis of optically selected high-z quasars showed an anticorrelation of αOX, the spectral index between the rest-frame 2500 Å and 2 keV, with optical luminosity. We examine this relationship by means of Monte Carlo simulations and conclude that a constant αOX independent of optical luminosity is still consistent with this high-z sample. We further find that contributions of large dispersions and narrow range of optical luminosity are most important for the apparent, yet artificial, αOX-lo correlation reported. We also examine another, but more complete, low-z optical selected <span class="hlt">AGN</span> sub-sample from Steffen et al., and our analysis shows that a constant αOX independent of optical luminosity is also consistent with the data. By comparing X-ray and optical luminosity functions, we find that a luminosity-independent αOX is in fact more preferred than the luminosity-dependent αOX <span class="hlt">model</span>. We also discuss the selection effects caused by flux limits, which might systematically bias the lX-lo relation and cause discrepancy in optically selected and X-ray selected <span class="hlt">AGN</span> samples. To correctly establish a dependence of αOX of <span class="hlt">AGNs</span> on their luminosity, a larger and more complete sample is needed and consequences of luminosity dispersions and selection effects in flux-limited samples must be taken into account properly.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFMSH51A0257V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFMSH51A0257V"><span>Data <span class="hlt">Unification</span> and Analysis Services for VxO"s</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vandegriff, J.; Merka, J.; Narock, T.; Szabo, A.</p> <p>2007-12-01</p> <p>We present a prototype data <span class="hlt">unification</span> mechanism for space physics data. The ultimate goal is to create a service that provides scientists with a simple yet scalable way to obtain immediately usable data from multiple, diverse, distributed data holdings. While emerging VxO's simplify the discovery of specific data products, the actual product files discovered are still in multiple formats and have widely varying layouts even with the same format. Thus when trying to make, for example, custom plots of data from different missions each of which uses a different format/layout, all the datasets must be first converted to a format and layout suitable for the researcher's own plotting tools, and this can be very time consuming and frustrating. Our service will read the data files from various online, remote locations and convert them into a standardized, internal representation. Once captured in a mission independent form, subsequent use of the data (display, analysis, output into other formats/layouts) can be completely ignorant of any dataset specific details. The prototype version of our service will be available as a set of IDL routines (i.e., a client side mechanism) that can be embedded into custom analysis programs, and eventually this functionality will be available through a REST style interface (i.e., a server side mechanism). The VxO's are an enabling piece of the <span class="hlt">unification</span> process because VxOs provide uniform metadata that allows the creation of conversion routines to bring the data into a mission independent internal representation. Access to a sampling of magnetic field and plasma datasets available through the Virtual Heliophsyics Observatory (VHO) and the Virtual Magnetospheric Observatory (VMO) will be demonstrated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/840225','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/840225"><span>Logarithmic <span class="hlt">unification</span> from symmetries enhanced in the sub-millimeter infrared</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Arkani-Hamed, Nima; Dimopoulos, Savas; March-Russell, John</p> <p>1999-08-21</p> <p>In theories with TeV string scale and sub-millimeter extra dimensions the attractive picture of logarithmic gauge coupling <span class="hlt">unification</span> at 10{sup 16} GeV is seemingly destroyed. In this paper we argue to the contrary that logarithmic <span class="hlt">unification</span> can occur in such theories. The rationale for <span class="hlt">unification</span> is no longer that a gauge symmetry is restored at short distances, but rather that a geometric symmetry is restored at large distances in the bulk away from our 3-brane. The apparent ''running'' of the gauge couplings to energies far above the string scale actually arises from the logarithmic variation of classical fields in (sets of) two large transverse dimensions. We present a number of N = 2 and N = 1 supersymmetric D-brane constructions illustrating this picture for <span class="hlt">unification</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MNRAS.tmp..166C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MNRAS.tmp..166C"><span>Unveiling slim accretion disc in <span class="hlt">AGN</span> through X-ray and Infrared observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Castelló-Mor, Núria; Kaspi, Shai; Netzer, Hagai; Du, Pu; Hu, Chen; Ho, Luis C.; Bai, Jin-Ming; Bian, Wei-Hao; Yuan, Ye-Fei; Wang, Jian-Min</p> <p>2017-01-01</p> <p>In this work, which is a continuation of Castello-Mor et al. (2016), we present new X-ray and infrared (IR) data for a sample of active galactic nuclei (<span class="hlt">AGN</span>) covering a wide range in Eddington ratio over a small luminosity range. In particular, we rigorously explore the dependence of the optical-to-X-ray spectral index αOX and the IR-to-optical spectral index on the dimensionless accretion rate, dot{M}=dot{m}/η where dot{m}=LAGN/LEdd and η is the mass-to-radiation conversion efficiency, in low and high accretion rate sources. We find that the SED of the faster accreting sources are surprisingly similar to those from the comparison sample of sources with lower accretion rate. In particular: I) the optical-to-UV <span class="hlt">AGN</span> SED of slow and fast accreting <span class="hlt">AGN</span> can be fitted with thin AD <span class="hlt">models</span>. II) The value of αOX is very similar in slow and fast accreting systems up to a dimensionless accretion rate dot{M}c ˜10. We only find a correlation between αOX and dot{M} for sources with dot{M}>dot{M}c. In such cases, the faster accreting sources appear to have systematically larger αOX values. III) We also find that the torus in the faster accreting systems seems to be less efficient in reprocessing the primary <span class="hlt">AGN</span> radiation having lower IR-to-optical spectral slopes. These findings, failing to recover the predicted differences between the SEDs of slim and thin ADs within the observed spectral window, suggest that additional physical processes or very special geometry act to reduce the extreme UV radiation in fast accreting <span class="hlt">AGN</span>. This may be related to photon trapping, strong winds, and perhaps other yet unknown physical processes.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApJ...836...20B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApJ...836...20B"><span>X-ray and Ultraviolet Properties of <span class="hlt">AGNs</span> in Nearby Dwarf Galaxies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Baldassare, Vivienne F.; Reines, Amy E.; Gallo, Elena; Greene, Jenny E.</p> <p>2017-02-01</p> <p>We present new Chandra X-ray Observatory and Hubble Space Telescope observations of eight optically selected broad-line active galactic nucleus (<span class="hlt">AGN</span>) candidates in nearby dwarf galaxies (z < 0.055). Including archival Chandra observations of three additional sources, our sample contains all 10 galaxies from Reines et al. (2013) with both broad Hα emission and narrow-line <span class="hlt">AGN</span> ratios (six <span class="hlt">AGNs</span>, four composites), as well as one low-metallicity dwarf galaxy with broad Hα and narrow-line ratios characteristic of star formation. All 11 galaxies are detected in X-rays. Nuclear X-ray luminosities range from L 0.5–7keV ≈ 5 × 1039 to 1 × 1042 ergs‑1. In all cases except for the star-forming galaxy, the nuclear X-ray luminosities are significantly higher than would be expected from X-ray binaries, providing strong confirmation that <span class="hlt">AGNs</span> and composite dwarf galaxies do indeed host actively accreting black holes (BHs). Using our estimated BH masses (which range from ∼7 × 104 to 1 × 106 M ⊙), we find inferred Eddington fractions ranging from ∼0.1% to 50%, i.e., comparable to massive broad-line quasars at higher redshift. We use the HST imaging to determine the ratio of UV to X-ray emission for these <span class="hlt">AGNs</span>, finding that they appear to be less X-ray luminous with respect to their UV emission than more massive quasars (i.e., α OX values an average of 0.36 lower than expected based on the relation between α OX and 2500 Å luminosity). Finally, we discuss our results in the context of different accretion <span class="hlt">models</span> onto nuclear BHs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/799037','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/799037"><span>Synergy Between Observations of <span class="hlt">AGN</span> with GLAST and MAXI</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Madejski, Grzegorz</p> <p>2002-03-25</p> <p>In five years' time we will witness the launch of two important missions developed to observe celestial sources in the high energy regime: GLAST, sensitive in the high energy {gamma}-ray band, and MAXI, the all-sky X-ray monitor. Simultaneous monitoring observations by the two instruments will be particularly valuable for variable sources, allowing cross-correlations of time series between the two bands. We present the anticipated results from such observations of active galaxies, and in particular, of the jet-dominated sub-class of <span class="hlt">AGN</span> known as blazars. We discuss the constraints on the structure and emission processes--and in particular, on the internal shock <span class="hlt">models</span> currently invoked to explain the particle acceleration processes in blazars--that can be derived with simultaneous {gamma}-ray and X-ray data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016agnt.confE..45M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016agnt.confE..45M"><span>Obscured <span class="hlt">AGN</span> With NuSTAR</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marinucci, Andrea; Bianchi, S.; Matt, G.; Balokovic, M.; Bauer, F. E.; Brandt W. N.; Gandhi, P.; Guainazzi, M.; Harrison, F.; Iwasawa, K.; Nicastro, F.; Puccetti, S.; Ricci, C.; Walton, D. J.; Stern, D.</p> <p>2016-10-01</p> <p>The Nuclear Spectroscopic Telescope Array (NuSTAR) is the first orbiting telescope to focus high energy X-ray light above 10 keV. Compared to the previous generation of coded mask observatories, this change in technology provides NuSTAR with 10x sharper images and 100x improved sensitivityThe unprecedented spectral quality in the 3-80 keV band has provided unique information about the circumnuclear reflecting environment of AGNI will present and discuss results from the NuSTAR observations of nearby Obscured <span class="hlt">AGN</span> in its first four years of science.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21607948','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21607948"><span>Sparticle spectroscopy with neutralino dark matter from t-b-{tau} quasi-Yukawa <span class="hlt">unification</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Dar, Shahida; Gogoladze, Ilia; Shafi, Qaisar; Uen, Cem Salih</p> <p>2011-10-15</p> <p>We consider two classes of t-b-{tau} quasi-Yukawa <span class="hlt">unification</span> scenarios which can arise from realistic supersymmetric SO(10) and SU(4){sub C}xSU(2){sub L}xSU(2){sub R} <span class="hlt">models</span>. We show that these scenarios can be successfully implemented in the nonuniversal Higgs <span class="hlt">model</span> with m{sub H{sub u}}=m{sub H{sub d}}{ne}m{sub 0} and the constrained minimal sumersymmetric <span class="hlt">model</span> frameworks, and they yield a variety of sparticle spectra with Wilkinson Microwave Anisotropy Probe compatible neutralino dark matter. In the nonuniversal Higgs <span class="hlt">model</span> with m{sub H{sub u}}=m{sub H{sub d}}{ne}m{sub 0}, we find bino-Higgsino dark matter as well as the stau coannihilation and A-funnel solutions. The constrained minimal sumersymmetric <span class="hlt">model</span> case yields the stau coannihilation and A-funnel solutions. The gluino and squark masses are found to lie in the TeV range.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ASPC..505..107L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ASPC..505..107L"><span>Clues to the Structure of <span class="hlt">AGN</span> Through Massive Variability Surveys</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lawrence, A.</p> <p>2016-06-01</p> <p>Variability studies hold information on otherwise unresolvable regions in Active Galactic Nuclei (<span class="hlt">AGN</span>). Population studies of large samples likewise have been very productive for our understanding of <span class="hlt">AGN</span>. These two themes are coming together in the idea of systematic variability studies of large samples - with SDSS, PanSTARRS, and soon, LSST. I summarise what we have learned about the optical and UV variability of <span class="hlt">AGN</span>, and what it tells us about accretion discs and the BLR. The most exciting recent results have focused on rare large-scale outbursts and collapses - Tidal Disruption Events, changing-look <span class="hlt">AGN</span>, and large amplitude microlensing. All of these promise to give us new insight into <span class="hlt">AGN</span> physics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AAS...207.2007V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AAS...207.2007V"><span>Searching for Compton-thick <span class="hlt">AGN</span> with INTEGRAL</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Virani, S. N.; Treister, E.; Urry, C. M.; Maccarone, T.; Bird, T.; Beckmann, V.; Lira, P.; Coppi, P.; Uchiyama, Y.</p> <p>2005-12-01</p> <p>The 30 keV peak in the X-ray background strongly suggests there should be a large number of highly obscured <span class="hlt">AGN</span> in the local universe. However, the exact number of these objects remains unknown, even though they could nearly double the space density of supermassive black holes. These Compton-thick <span class="hlt">AGN</span> can be detected in the hard X-rays with INTEGRAL. As part of the current observing cycle, we were awarded 2 Msec to perform INTEGRAL imaging of the XMM-LSS field in order to find highly obscured <span class="hlt">AGN</span> in the local Universe. In this paper, we present preliminary results for the ˜1 Ms of IBIS data obtained so far, including new hard X-ray detections of <span class="hlt">AGN</span>. We also present the 20---200 keV spectra of the brightest <span class="hlt">AGN</span> including the z<0.1 Seyfert galaxies NGC 788, NGC 1068, and NGC 1142.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016MNRAS.461.2374C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MNRAS.461.2374C"><span>Exploring <span class="hlt">AGN</span>-starburst coexistence in galaxies at z ˜ 0.8 using the [O III]4959+5007/[O III]4363 line ratio</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Contini, M.</p> <p>2016-09-01</p> <p>Using detailed <span class="hlt">modelling</span>, we analyse the spectra observed from the sample galaxies at z ˜ 0.8 presented by Ly et al., constraining the <span class="hlt">models</span> by the [O III]5007+4959/[O III]4363 line ratios. Composite <span class="hlt">models</span> (shock + photoionization) are adopted. Shock velocities ≥100 km s-1 and pre-shock densities n0 ˜ 200 cm-3 characterize the gas surrounding the starburst (SB), while n0 are higher by a factor of 1.5-10 in the <span class="hlt">AGN</span> emitting gas. SB effective temperatures are similar to those of quiescent galaxies (T* ˜ 4-7 × 104 K). Cloud geometrical thicknesses in the SB are ≤1016 cm, indicating major fragmentation, while in <span class="hlt">AGN</span> they reach >10 pc. O/H are about solar for all the objects, except for a few <span class="hlt">AGN</span> clouds with O/H = 0.3-0.5 solar. SB <span class="hlt">models</span> reproduce most of the data within the observational errors. About half of the objects' spectra are well fitted by an accreting <span class="hlt">AGN</span>. Some galaxies show multiple radiation sources, such as SB + <span class="hlt">AGN</span>, or a double <span class="hlt">AGN</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015MNRAS.453.2075K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015MNRAS.453.2075K"><span>Do the Kepler <span class="hlt">AGN</span> light curves need reprocessing?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kasliwal, Vishal P.; Vogeley, Michael S.; Richards, Gordon T.; Williams, Joshua; Carini, Michael T.</p> <p>2015-10-01</p> <p>We gauge the impact of spacecraft-induced effects on the inferred variability properties of the light curve of the Seyfert 1 <span class="hlt">AGN</span> Zw 229-15 observed by Kepler. We compare the light curve of Zw 229-15 obtained from the Kepler MAST data base with a reprocessed light curve constructed from raw pixel data. We use the first-order structure function, SF(δt), to fit both light curves to the damped power-law PSD (power spectral density) of Kasliwal et al. On short time-scales, we find a steeper log PSD slope (γ = 2.90 to within 10 per cent) for the reprocessed light curve as compared to the light curve found on MAST (γ = 2.65 to within 10 per cent) - both inconsistent with a damped random walk (DRW) which requires γ = 2. The log PSD slope inferred for the reprocessed light curve is consistent with previous results that study the same reprocessed light curve. The turnover time-scale is almost identical for both light curves (27.1 and 27.5 d for the reprocessed and MAST data base light curves). Based on the obvious visual difference between the two versions of the light curve and on the PSD <span class="hlt">model</span> fits, we conclude that there remain significant levels of spacecraft-induced effects in the standard pipeline reduction of the Kepler data. Reprocessing the light curves will change the <span class="hlt">model</span> inferenced from the data but is unlikely to change the overall scientific conclusions reached by Kasliwal et al. - not all <span class="hlt">AGN</span> light curves are consistent with the DRW.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApJ...817..108W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApJ...817..108W"><span>The Prevalence of Gas Outflows in Type 2 <span class="hlt">AGNs</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Woo, Jong-Hak; Bae, Hyun-Jin; Son, Donghoon; Karouzos, Marios</p> <p>2016-02-01</p> <p>To constrain the nature and fraction of the ionized gas outflows in active galactic nuclei (<span class="hlt">AGNs</span>), we perform a detailed analysis on gas kinematics as manifested by the velocity dispersion and shift of the [{{O}}\\{{III}}] λ5007 emission line, using a large sample of ˜39,000 type 2 <span class="hlt">AGNs</span> at z < 0.3. First, we confirm a broad correlation between [{{O}} {{III}}] and stellar velocity dispersions, indicating that the bulge gravitational potential plays a main role in determining the [{{O}} {{III}}] kinematics. However, [{{O}} {{III}}] velocity dispersion is on average larger than stellar velocity dispersion by a factor of 1.3-1.4 for <span class="hlt">AGNs</span> with double Gaussian [{{O}} {{III}}], suggesting that the non-gravitational component, i.e., outflows, is almost comparable to the gravitational component. Second, the increase of the [{{O}} {{III}}] velocity dispersion (after normalized by stellar velocity dispersion) with both <span class="hlt">AGN</span> luminosity and Eddington ratio suggests that non-gravitational kinematics are clearly linked to <span class="hlt">AGN</span> accretion. The distribution in the [{{O}} {{III}}] velocity-velocity dispersion diagram dramatically expands toward large values with increasing <span class="hlt">AGN</span> luminosity, implying that the launching velocity of gas outflows increases with <span class="hlt">AGN</span> luminosity. Third, the majority of luminous <span class="hlt">AGNs</span> present the non-gravitational kinematics in the [{{O}} {{III}}] profile. These results suggest that ionized gas outflows are prevalent among type 2 <span class="hlt">AGNs</span>. On the other hand, we find no strong trend of the [{{O}} {{III}}] kinematics with radio luminosity, once we remove the effect of the bulge gravitational potential, indicating that ionized gas outflows are not directly related to radio activity for the majority of type 2 <span class="hlt">AGNs</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020091604','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020091604"><span>X-ray Properties of the Central kpc of <span class="hlt">AGN</span> and Starbursts: The Latest News from Chandra</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Weaver, Kimberly A.; White, Nicholas E. (Technical Monitor)</p> <p>2001-01-01</p> <p>The X-ray properties of 15 nearby (v less than 3,000 km/s) galaxies that possess <span class="hlt">AGN</span> (active galactic nuclei) and/or starbursts are discussed. Two-thirds have nuclear extended emission on scales from approx. 0.5 to approx. 1.5 kpc that is either clearly associated with a nuclear outflow or morphologically resembles an outflow. Galaxies that are <span class="hlt">AGN</span>-dominated tend to have linear structures while starburst-dominated galaxies tend to have plume-like structures. Significant X-ray absorption is present in the starburst regions, indicating that a circumnuclear starburst is sufficient to block an <span class="hlt">AGN</span> at optical wavelengths. Galaxies with starburst activity possess more X-ray point sources within their central kpc than non-starbursts. Many of these sources are more luminous than typical X-ray binaries. The Chandra results are discussed in terms of the starburst-<span class="hlt">AGN</span> connection, a revised unified <span class="hlt">model</span> for <span class="hlt">AGN</span>, and possible evolutionary scenarios.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvD..95f5008B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvD..95f5008B"><span>Two loop <span class="hlt">unification</span> of non-SUSY SO(10) GUT with TeV scalars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brennan, T. Daniel</p> <p>2017-03-01</p> <p>In this paper we examine gauge coupling <span class="hlt">unification</span> of the non-SUSY SO(10) grand unified theory proposed by Babu and Mohapatra [Phys. Lett. B 715, 328 (2012), 10.1016/j.physletb.2012.08.006] at the two loop level. This theory breaks down to the standard <span class="hlt">model</span> in a single step and has the distinguishing feature of TeV nonstandard <span class="hlt">model</span> scalars. This leads to a plethora of interesting new physics at the TeV scale and the discovery of new particles at the LHC. This <span class="hlt">model</span> gives rise to testable proton decay, neutron-antineutron oscillations, provides a mechanism for baryogenesis, and contains potential dark matter candidates. In this paper, we compute the two loop beta function and show that this <span class="hlt">model</span> unifies to two loop order around 1 015 GeV . We then compute the proton lifetime, taking into account threshold effects and show that these effects place it above the Super-Kamiokande limit [K. Abe et al. (Super-Kamiokande Collaboration), Phys. Rev. D 95, 012004 (2017)., 10.1103/PhysRevD.95.012004].</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014MNRAS.445...81S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014MNRAS.445...81S"><span>The jet-disc connection in <span class="hlt">AGN</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sbarrato, T.; Padovani, P.; Ghisellini, G.</p> <p>2014-11-01</p> <p>We present our latest results on the connection between accretion rate and relativistic jet power in active galactic nuclei (<span class="hlt">AGN</span>), by using a large sample which includes mostly blazars, but contains also some radio galaxies. The jet power can be traced by γ-ray luminosity in the case of blazars, and radio luminosity for both classes. The accretion-disc luminosity is instead traced by the broad emission lines. Among blazars, we find a correlation between broad line emission and the γ-ray or radio luminosities, suggesting a direct tight connection between jet power and accretion rate. We confirm that the observational differences between blazar subclasses reflect differences in the accretion regime, but with blazars only we cannot properly access the low-accretion regime. By introducing radio galaxies, we succeed in observing the fingerprint of the transition between radiatively efficient and inefficient accretion discs in the jetted <span class="hlt">AGN</span> family. The transition occurs at the standard critical value Ld/LEdd ˜ 10-2 and it appears smooth. Below this value, the ionizing luminosity emitted by the accretion structure drops significantly.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JHEP...10..088B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JHEP...10..088B"><span>Light staus and enhanced Higgs diphoton rate with non-universal gaugino masses and SO(10) Yukawa <span class="hlt">unification</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Badziak, Marcin; Olechowski, Marek; Pokorski, Stefan</p> <p>2013-10-01</p> <p>It is shown that substantially enhanced Higgs to diphoton rate induced by light staus with large left-right mixing in MSSM requires at the GUT scale non-universal gaugino masses with bino and/or wino lighter than gluino. The possibility of such enhancement is investigated in MSSM <span class="hlt">models</span> with arbitrary gaugino masses at the GUT scale with additional restriction of top-bottom-tau Yukawa <span class="hlt">unification</span>, as predicted by minimal SO(10) GUTs. Many patterns of gaugino masses leading to enhanced Higgs to diphoton rate and the Yukawa <span class="hlt">unification</span> are identified. Some of these patterns can be accommodated in a well-motivated scenarios such as mirage mediation or SUSY breaking F -terms being a non- singlet of SO(10). Phenomenological implications of a scenario with non-universal gaugino masses generated by a mixture of the singlet F -term and the F -term in a 24-dimensional representation of SU(5) ⊂ SO(10) are studied in detail. Possible non-universalities of other soft terms generated by such F-terms are discussed. The enhancement of Higgs to diphoton rate up to 30% can be obtained in agreement with all phenomenological constraints, including vacuum metastability bounds. The lightest sbottom and pseudoscalar Higgs are within easy reach of the 14 TeV LHC. The LSP can be either bino-like or wino-like. The thermal relic abundance in the former case may be in agreement with the cosmological data thanks to efficient stau coannihilation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015MNRAS.449.4105C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015MNRAS.449.4105C"><span>The impact of mechanical <span class="hlt">AGN</span> feedback on the formation of massive early-type galaxies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Choi, Ena; Ostriker, Jeremiah P.; Naab, Thorsten; Oser, Ludwig; Moster, Benjamin P.</p> <p>2015-06-01</p> <p>We employ cosmological hydrodynamical simulations to investigate the effects of <span class="hlt">AGN</span> feedback on the formation of massive galaxies with present-day stellar masses of M_stel= 8.8 × 10^{10}-6.0 × 10^{11} M_{⊙}. Using smoothed particle hydrodynamics simulations with a pressure-entropy formulation that allows an improved treatment of contact discontinuities and fluid mixing, we run three sets of simulations of 20 haloes with different <span class="hlt">AGN</span> feedback <span class="hlt">models</span>: (1) no feedback, (2) thermal feedback, and (3) mechanical and radiation feedback. We assume that seed black holes are present at early cosmic epochs at the centre of emerging dark matter haloes and trace their mass growth via gas accretion and mergers with other black holes. Both feedback <span class="hlt">models</span> successfully recover the observed MBH-σ relation and black hole-to-stellar mass ratio for simulated central early-type galaxies. The baryonic conversion efficiencies are reduced by a factor of 2 compared to <span class="hlt">models</span> without any <span class="hlt">AGN</span> feedback at all halo masses. However, massive galaxies simulated with thermal <span class="hlt">AGN</span> feedback show a factor of ˜10-100 higher X-ray luminosities than observed. The mechanical/radiation feedback <span class="hlt">model</span> reproduces the observed correlation between X-ray luminosities and velocity dispersion, e.g. for galaxies with σ = 200 km s- 1, the X-ray luminosity is reduced from 1042 erg s- 1 to 1040 erg s- 1. It also efficiently suppresses late-time star formation, reducing the specific star formation rate from 10-10.5 yr- 1 to 10-14 yr- 1 on average and resulting in quiescent galaxies since z = 2, whereas the thermal feedback <span class="hlt">model</span> shows higher late-time in situ star formation rates than observed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008yCat..34870475P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008yCat..34870475P"><span>VizieR Online Data Catalog: X-ray variability of <span class="hlt">AGNs</span> in Lockman Hole (Papadakis+, 2008)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Papadakis, I. E.; Chatzopoulos, E.; Athanasiadis, D.; Markowitz, A.; Georgantopoulos, I.</p> <p>2008-05-01</p> <p>We present the results from a detailed X-ray variability analysis of 66 <span class="hlt">AGN</span> in the Lockman Hole, which have optical spectroscopic identifications. We compare, quantitatively, their variability properties with the properties of local <span class="hlt">AGN</span>, and we study the "variability - luminosity" relation as a function of redshift, and the "variability - redshift" relation in two luminosity bins. We use archival data from the last 10 XMM-Newton observations of the Lockman Hole field to extract light curves in the rest frame, 2-10keV band. We use the "normalized excess variance" to quantify the variability amplitude. Using the latest results regarding the <span class="hlt">AGN</span> power spectral shape and its dependence on black hole mass and accretion rate, we are able to compute <span class="hlt">model</span> "variability - luminosity" curves, which we compare with the relations we observe. When we consider all the sources in our sample, we find that their variability amplitude decreases with increasing redshift and luminosity. (1 data file).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016A%26A...594A..73A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016A%26A...594A..73A"><span>Compton-thick <span class="hlt">AGN</span> in the 70-month Swift-BAT All-Sky Hard X-ray Survey: A Bayesian approach</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Akylas, A.; Georgantopoulos, I.; Ranalli, P.; Gkiokas, E.; Corral, A.; Lanzuisi, G.</p> <p>2016-10-01</p> <p>The 70-month Swift-BAT catalogue provides a sensitive view of the extragalactic X-ray sky at hard energies (>10 keV) containing about 800 active galactic nuclei (<span class="hlt">AGN</span>). We explore its content in heavily obscured, Compton-thick <span class="hlt">AGN</span> by combining the BAT (14-195 keV) with the lower energy XRT (0.3-10 keV) data. We apply a Bayesian methodology using Markov chains to estimate the exact probability distribution of the column density for each source. We find 53 possible Compton-thick sources (probability range 3-100%) translating to a ~7% fraction of the <span class="hlt">AGN</span> in our sample. We derive the first parametric luminosity function of Compton-thick <span class="hlt">AGN</span>. The unabsorbed luminosity function can be represented by a double power law with a break at L⋆ ~ 2 × 1042erg s-1 in the 20-40 keV band. The Compton-thick <span class="hlt">AGN</span> contribute ~17% of the total <span class="hlt">AGN</span> emissivity. We derive an accurate Compton-thick number count distribution taking into account the exact probability of a source being Compton-thick and the flux uncertainties. This number count distribution is critical for the calibration of the X-ray background synthesis <span class="hlt">models</span>, i.e. for constraining the intrinsic fraction of Compton-thick <span class="hlt">AGN</span>. We find that the number counts distribution in the 14-195 keV band agrees well with our <span class="hlt">models</span> which adopt a low intrinsic fraction of Compton-thick <span class="hlt">AGN</span> (~ 12%) among the total <span class="hlt">AGN</span> population and a reflected emission of ~ 5%. In the extreme case of zero reflection, the number counts can be <span class="hlt">modelled</span> with a fraction of at most 30% Compton-thick <span class="hlt">AGN</span> of the total <span class="hlt">AGN</span> population and no reflection. Moreover, we compare our X-ray background synthesis <span class="hlt">models</span> with the number counts in the softer 2-10 keV band. This band is more sensitive to the reflected component and thus helps us to break the degeneracy between the fraction of Compton-thick <span class="hlt">AGN</span> and the reflection emission. The number counts in the 2-10 keV band are well above the <span class="hlt">models</span> which assume a 30% Compton-thick <span class="hlt">AGN</span> fraction and zero reflection, while</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20080037805&hterms=Wisdom&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DWisdom','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20080037805&hterms=Wisdom&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DWisdom"><span>Mini-Survey on SDSS OIII <span class="hlt">AGN</span> with Swift</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Angelini, Lorella</p> <p>2008-01-01</p> <p>The number of <span class="hlt">AGN</span> and their luminosity distribution are crucial parameters for our understanding of the <span class="hlt">AGN</span> phenomenon. There is a common wisdom that every massive galaxy has a massive black hole. However, most of these objects either are not radiating or until recently have been very difficult to detect. The Sloan Digital Sky Survey (SDSS) data, based on the [OIII] line indicate that perhaps up to 20% of all galaxies may be classified as <span class="hlt">AGN</span> a surprising result that must be checked with independent data. X-ray surveys have revealed that hard X-ray selected <span class="hlt">AGN</span> show a strong luminosity dependent evolution and their luminosity function (LF) shows a dramatic break towards low $L_X$ (at all $z$). This is seen for all types of <span class="hlt">AGN</span>, but is stronger for the broad-line objects. In sharp contrast, the local LF of {it optically-selected samples} shows no such break and no differences between narrow and broad-line objects. Assuming both hard X-ray and [O{\\sc iii}] emission are fair indicators of <span class="hlt">AGN</span> activity, it is important to understand this discrepancy. We present here the results of a min-survey done with Swift on a selected sample of SDSS selected <span class="hlt">AGN</span>. The objects have been sampled at different L([O{\\sc iii}]) to check the relation with the $L_X$ observed with Swift.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/15020358','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/15020358"><span>Spectral decomposition of broad-line <span class="hlt">agns</span> and host galaxies</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Vanden Berk, Daniel E.; Shen, Jiajian; Yip, Ching-Wa; Schneider, Donald P.; Connolly, Andrew J.; Burton, Ross E.; Jester, Sebastian; Hall, Patrick B.; Szalay, Alex S.; Brinkmann, John; /Apache Point Observ.</p> <p>2005-09-01</p> <p>Using an eigenspectrum decomposition technique, we separate the host galaxy from the broad line active galactic nucleus (<span class="hlt">AGN</span>) in a set of 4666 spectra from the Sloan Digital Sky Survey (SDSS), from redshifts near zero up to about 0.75. The decomposition technique uses separate sets of galaxy and quasar eigenspectra to efficiently and reliably separate the <span class="hlt">AGN</span> and host spectroscopic components. The technique accurately reproduces the host galaxy spectrum, its contributing fraction, and its classification. We show how the accuracy of the decomposition depends upon S/N, host galaxy fraction, and the galaxy class. Based on the eigencoefficients, the sample of SDSS broad-line <span class="hlt">AGN</span> host galaxies spans a wide range of spectral types, but the distribution differs significantly from inactive galaxies. In particular, post-starburst activity appears to be much more common among <span class="hlt">AGN</span> host galaxies. The luminosities of the hosts are much higher than expected for normal early-type galaxies, and their colors become increasingly bluer than early-type galaxies with increasing host luminosity. Most of the <span class="hlt">AGNs</span> with detected hosts are emitting at between 1% and 10% of their estimated Eddington luminosities, but the sensitivity of the technique usually does not extend to the Eddington limit. There are mild correlations among the <span class="hlt">AGN</span> and host galaxy eigencoefficients, possibly indicating a link between recent star formation and the onset of <span class="hlt">AGN</span> activity. The catalog of spectral reconstruction parameters is available as an electronic table.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016agnw.confE..28G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016agnw.confE..28G"><span>Compton Thick <span class="hlt">AGN</span> in the 70 Month Swift-BAT All-Sky Hard X-ray Survey: a Bayesian approach</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Georgantopoulos, I.; Akylas, A.; Ranalli, P.; Corral, A.; Lanzuisi, G.</p> <p>2016-08-01</p> <p>The 70 month Swift/BAT catalogue provides a sensitive view of the extragalactic X-ray sky at hard energies 14-195 keV containing about 800 Active Galactic Nuclei. We explore its content in heavily obscured Compton-thick <span class="hlt">AGN</span> by combining the BAT (14-195 keV) with the XRT data (0.3-10 keV) at lower energies. We apply a Bayesian methodology using Markov chains to estimate the exact probability distribution of the column density. We find 54 possible Compton-thick sources (from 3 to 100 % probability) translating to a 7% fraction of the total <span class="hlt">AGN</span> population. We derive an accurate Compton-thick number count distribution taking into account the exact probability of a source being Compton-thick as well as the flux errors. The number density of Compton-thick <span class="hlt">AGN</span> is critical for the calibration of X-ray background synthesis <span class="hlt">models</span>. We find that the number count distribution agrees with <span class="hlt">models</span> that adopt a low intrinsic fraction of Compton-thick <span class="hlt">AGN</span> (15%) among the total <span class="hlt">AGN</span> population and a reflected emission of (~5%). Finally, we derive the first parametric luminosity function of Compton-thick <span class="hlt">AGN</span> in the local universe. The unabsorbed luminosity function can be represented by a double power-law with a break at L* ~2 x 10^42 ergs in the 20-40 keV band. The Compton-thick <span class="hlt">AGN</span> constitute a substantial fraction of the <span class="hlt">AGN</span> density at low luminosities (<10^42 erg/s).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MNRAS.466..677G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MNRAS.466..677G"><span>Raining on black holes and massive galaxies: the top-down multiphase condensation <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gaspari, M.; Temi, P.; Brighenti, F.</p> <p>2017-04-01</p> <p>The plasma haloes filling massive galaxies, groups and clusters are shaped by active galactic nucleus (<span class="hlt">AGN</span>) heating and subsonic turbulence (σv ∼ 150 km s-1), as probed by Hitomi. Novel 3D high-resolution simulations show the soft X-ray, keV hot plasma cools rapidly via radiative emission at the high-density interface of the turbulent eddies, stimulating a top-down condensation cascade of warm 104 K filaments. The kpc-scale ionized (optical/ultraviolet) filaments form a skin enveloping the neutral filaments (optical/infrared/21 cm). The peaks of the warm filaments further condense into cold molecular clouds (<50 K; radio) with total mass of several 107 M⊙ and inheriting the turbulent kinematics. In the core, the clouds collide inelastically, mixing angular momentum and leading to Chaotic Cold Accretion (CCA). The black hole accretion rate (BHAR) can be <span class="hlt">modelled</span> via quasi-spherical viscous accretion, dot{M}_bullet ∝ ν _c, with clump collisional viscosity νc ≡ λc σv and λc ∼ 100 pc. Beyond the core, pressure torques shape the angular momentum transport. In CCA, the BHAR is recurrently boosted up to 2 dex compared with the disc evolution, which arises as turbulence becomes subdominant. With negligible rotation too, compressional heating inhibits the molecular phase. The CCA BHAR distribution is lognormal with pink noise, f-1 power spectrum characteristic of fractal phenomena. Such chaotic fluctuations can explain the rapid luminosity variability of <span class="hlt">AGN</span> and high-mass X-ray binaries. An improved criterium to trace non-linear condensation is proposed: σv/vcool ≲ 1. The three-phase CCA reproduces key observations of cospatial multiphase gas in massive galaxies, including Chandra X-ray images, SOAR Hα filaments and kinematics, Herschel [C+] emission and ALMA molecular associations. CCA plays important role in <span class="hlt">AGN</span> feedback and <span class="hlt">unification</span>, the evolution of BHs, galaxies and clusters.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JHEP...07..149H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JHEP...07..149H"><span>750 GeV diphotons: implications for supersymmetric <span class="hlt">unification</span> II</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hall, Lawrence J.; Harigaya, Keisuke; Nomura, Yasunori</p> <p>2016-07-01</p> <p>Perturbative supersymmetric gauge coupling <span class="hlt">unification</span> is possible in six theories where complete SU (5) TeV-scale multiplets of vector matter account for the size of the reported 750 GeV diphoton resonance, interpreted as a singlet multiplet S=(s+ia)/√{2} . One of these has a full generation of vector matter and a unified gauge coupling α G ˜ 1. The diphoton signal rate is enhanced by loops of vector squarks and sleptons, especially when the trilinear A couplings are large. If the SH u H d coupling is absent, both s and a can contribute to the resonance, which may then have a large apparent width if the mass splitting from s and a arises from loops of vector matter. The width depends sensitively on A parameters and phases of the vector squark and slepton masses. Vector quarks and/or squarks are expected to be in reach of the LHC. If the SH u H d coupling is present, a leads to a narrow diphoton resonance, while a second resonance with decays s → hh, W + W - , ZZ is likely to be discovered at future LHC runs. In some of the theories a non-standard origin or running of the soft parameters is required, for example involving conformal hidden sector interactions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/377148','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/377148"><span>Toward <span class="hlt">unification</span> of taxonomy databases in a distributed computer environment</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kitakami, Hajime; Tateno, Yoshio; Gojobori, Takashi</p> <p>1994-12-31</p> <p>All the taxonomy databases constructed with the DNA databases of the international DNA data banks are powerful electronic dictionaries which aid in biological research by computer. The taxonomy databases are, however not consistently unified with a relational format. If we can achieve consistent <span class="hlt">unification</span> of the taxonomy databases, it will be useful in comparing many research results, and investigating future research directions from existent research results. In particular, it will be useful in comparing relationships between phylogenetic trees inferred from molecular data and those constructed from morphological data. The goal of the present study is to unify the existent taxonomy databases and eliminate inconsistencies (errors) that are present in them. Inconsistencies occur particularly in the restructuring of the existent taxonomy databases, since classification rules for constructing the taxonomy have rapidly changed with biological advancements. A repair system is needed to remove inconsistencies in each data bank and mismatches among data banks. This paper describes a new methodology for removing both inconsistencies and mismatches from the databases on a distributed computer environment. The methodology is implemented in a relational database management system, SYBASE.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994NuPhB.432...49B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994NuPhB.432...49B"><span>Flavour in supersymmetric Grand <span class="hlt">Unification</span>: A democratic approach</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barbieri, Riccardo; Dvali, Gia; Strumia, Alessandro; Berezhiani, Zurab; Hall, Lawrence</p> <p>1994-12-01</p> <p>We consider the flavour problem in a supersymmetric Grand Unified theory with gauged SU(6) group, where the Higgs doublets are understood as pseudo-Goldstone bosons of a larger SU(6) ⊗ SU(6) global symmetry of the Higgs superpotential. A key element of this work is that we never appeal to any flavour symmetry. One main interesting feature emerges: only one of the light fermions, an up-type quark, to be identified with the top, can get a Yukawa coupling at renormalizable level. This fact, together with bottom-tau Yukawa <span class="hlt">unification</span>, also implied in our scheme, gives rise to a characteristic correlation between the top and the Higgs mass. By including a flavour-blind discrete symmetry and requiring that all higher dimensional operators be mediated by the exchanges of appropriate heavy multiplets, it is possible to give an approximate description of all masses and mixing angles in term of a hierarchy of Grand Unified scales. A special "texture" arises, implying a relation between the top mass and the third generation mixing angles. Several other possible consequences of this approach are pointed out, concerning the μ/s mass ratio, the Cabibbo angle and the proton decay.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4145176','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4145176"><span><span class="hlt">Unification</span> of Neuronal Spikes, Seizures, and Spreading Depression</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wei, Yina; Ullah, Ghanim</p> <p>2014-01-01</p> <p>The pathological phenomena of seizures and spreading depression have long been considered separate physiological events in the brain. By incorporating conservation of particles and charge, and accounting for the energy required to restore ionic gradients, we extend the classic Hodgkin–Huxley formalism to uncover a <span class="hlt">unification</span> of neuronal membrane dynamics. By examining the dynamics as a function of potassium and oxygen, we now account for a wide range of neuronal activities, from spikes to seizures, spreading depression (whether high potassium or hypoxia induced), mixed seizure and spreading depression states, and the terminal anoxic “wave of death.” Such a unified framework demonstrates that all of these dynamics lie along a continuum of the repertoire of the neuron membrane. Our results demonstrate that unified frameworks for neuronal dynamics are feasible, can be achieved using existing biological structures and universal physical conservation principles, and may be of substantial importance in enabling our understanding of brain activity and in the control of pathological states. PMID:25164668</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19870051112&hterms=john+morris&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Djohn%2Bmorris','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19870051112&hterms=john+morris&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Djohn%2Bmorris"><span>X-ray-selected <span class="hlt">AGNs</span> near bright galaxies</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stocke, John T.; Schneider, Peter; Morris, Simon L.; Gioia, Isabella M.; Maccacaro, Tommaso</p> <p>1987-01-01</p> <p>Among the numerous low-redshift low-luminosity X-ray sources discovered with the Einstein Observatory, ten <span class="hlt">AGNs</span> were identified that are projected within three optical diameters of bright (V less than 18) foreground galaxies. These <span class="hlt">AGNs</span> near galaxies have significantly higher redshifts than the sample as a whole. This discovery is interpreted in terms of gravitational 'microlensing' in which stars in the foreground galaxy have significantly brightened the X-ray emission from these higher redshift <span class="hlt">AGNs</span>, allowing their detection. It is suggested that microlensing may be responsible for a significant alteration of the inherent QSO luminosity function.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008ApJ...688..190C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008ApJ...688..190C"><span>Chandra Evidence for <span class="hlt">AGN</span> Feedback in the Spiral Galaxy NGC 6764</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Croston, J. H.; Hardcastle, M. J.; Kharb, P.; Kraft, R. P.; Hota, A.</p> <p>2008-11-01</p> <p>We report the Chandra detection of X-ray emission spatially coincident with the kiloparsec-scale radio bubbles in the nearby (DL ~ 31 Mpc) <span class="hlt">AGN</span>-starburst galaxy NGC 6764. The X-ray emission originates in hot gas (kT ~ 0.75 keV), which may either be contained within the radio bubbles, or in a shell of hot gas surrounding them. We consider three <span class="hlt">models</span> for the origin of the hot gas: (1) a starburst-driven galactic wind, (2) shocked gas associated with the expanding radio bubbles, and (3) gas heated and entrained into the bubbles by jet/ISM interactions in the inner <span class="hlt">AGN</span> outflow. We rule out a galactic wind based on significant differences from known galactic wind systems. The tight correspondence between the brightest X-ray emission and the radio emission in the inner outflow from the Seyfert nucleus, as well as a correlation between X-ray and radio spectral features suggestive of shocks and particle acceleration, lead us to favor the third <span class="hlt">model</span>; however, we cannot firmly rule out a <span class="hlt">model</span> in which the bubbles are driving large-scale shocks into the galaxy ISM. In either <span class="hlt">AGN</span>-driven heating scenario, the total energy stored in the hot gas is high, ~1056 ergs, comparable to the energetic impact of low-power radio galaxies such as Centaurus A, and will have a dramatic impact on the galaxy and its surroundings.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016MNRAS.456.1960S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MNRAS.456.1960S"><span>Accretion disc time lag distributions: applying CREAM to simulated <span class="hlt">AGN</span> light curves</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Starkey, D. A.; Horne, Keith; Villforth, C.</p> <p>2016-02-01</p> <p>Active galactic nuclei (<span class="hlt">AGN</span>) vary in their brightness across all wavelengths. Moreover, longer wavelength ultraviolet-optical continuum light curves appear to be delayed with respect to shorter wavelength light curves. A simple way to <span class="hlt">model</span> these delays is by assuming thermal reprocessing of a variable point source (a lamp post) by a blackbody accretion disc. We introduce a new method, CREAM (Continuum REprocessed <span class="hlt">AGN</span> Markov Chain Monte Carlo), that <span class="hlt">models</span> continuum variations using this lamp post <span class="hlt">model</span>. The disc light curves lag the lamp post emission with a time delay distribution sensitive to the disc temperature-radius profile and inclination. We test CREAM's ability to recover both inclination and product of black hole mass and accretion rate {Mdot{M}}, and show that the code is also able to infer the shape of the driving light curve. CREAM is applied to synthetic light curves expected from 1000 s exposures of a 17th magnitude <span class="hlt">AGN</span> with a 2-m telescope in Sloan g and i bands with Signal-to-Noise Ratio (SNR) of 500-900 depending on the filter and lunar phase. We also test CREAM on poorer quality g and i light curves with SNR = 100. We find in the high-SNR case that CREAM can recover the accretion disc inclination to within an uncertainty of 5° and an {Mdot{M}} to within 0.04 dex.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EPJA...52..270C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EPJA...52..270C"><span>On the <span class="hlt">unification</span> of nuclear-structure theory: A response to Bortignon and Broglia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cook, Norman D.</p> <p>2016-09-01</p> <p>Nuclear-structure theory is unusual among the diverse fields of quantum physics. Although it provides a coherent description of all known isotopes on the basis of a quantum-mechanical understanding of nucleon states, nevertheless, in the absence of a fundamental theory of the nuclear force acting between nucleons, the prediction of all ground-state and excited-state nuclear binding energies is inherently semi-empirical. I suggest that progress can be made by returning to the foundational work of Eugene Wigner from 1937, where the mathematical symmetries of nucleon states were first defined. Those symmetries were later successfully exploited in the development of the independent-particle <span class="hlt">model</span> ( IPM ˜ shell <span class="hlt">model</span> , but the geometrical implications noted by Wigner were neglected. Here I review how the quantum-mechanical, but remarkably easy-to-understand geometrical interpretation of the IPM provides constraints on the parametrization of the nuclear force. The proposed "geometrical IPM" indicates a way forward toward the <span class="hlt">unification</span> of nuclear-structure theory that Bortignon and Broglia have called for.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23815662','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23815662"><span><span class="hlt">Unification</span> of regression-based methods for the analysis of natural selection.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Morrissey, Michael B; Sakrejda, Krzysztof</p> <p>2013-07-01</p> <p>Regression analyses are central to characterization of the form and strength of natural selection in nature. Two common analyses that are currently used to characterize selection are (1) least squares-based approximation of the individual relative fitness surface for the purpose of obtaining quantitatively useful selection gradients, and (2) spline-based estimation of (absolute) fitness functions to obtain flexible inference of the shape of functions by which fitness and phenotype are related. These two sets of methodologies are often implemented in parallel to provide complementary inferences of the form of natural selection. We unify these two analyses, providing a method whereby selection gradients can be obtained for a given observed distribution of phenotype and characterization of a function relating phenotype to fitness. The method allows quantitatively useful selection gradients to be obtained from analyses of selection that adequately <span class="hlt">model</span> nonnormal distributions of fitness, and provides <span class="hlt">unification</span> of the two previously separate regression-based fitness analyses. We demonstrate the method by calculating directional and quadratic selection gradients associated with a smooth regression-based generalized additive <span class="hlt">model</span> of the relationship between neonatal survival and the phenotypic traits of gestation length and birth mass in humans.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016pas..conf...72R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016pas..conf...72R"><span><span class="hlt">AGN</span> warm absorption with the ATHENA</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Różańska, Agata; Gronkiewicz, Dominik; Hryniewicz, Krzysztof; Adhikari, Tek Prasad; Rataj, Mirosław; Skup, Konrad</p> <p>2016-06-01</p> <p>X-ray astronomy requires satellites to make progress in searching the distribution of hot matter in the Universe. Approximately 15 years period of time is needed for full construction of the flight instrument from the mission concept up to the launch. A new generation X-ray telescope ATHENA (the Advanced Telescope for High Energy Astrophysics) was approved by European Space Agency as a large mission with a launch foreseen in 2028. In this paper we show how microcalorimeter on the board of ATHENA will help us to study warm absorption observed in active galactic nuclei (<span class="hlt">AGN</span>). We show that future observations will allow us to identify hundreds of lines from highly ionized elements and to measure Galactic warm absorption with very high precision.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016agnt.confE..24T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016agnt.confE..24T"><span>Inter-Stellar Medium Absorption Lines As Outflow Tracers - A Comparison Between <span class="hlt">AGNs</span> And SFGs</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Talia, Margherita; Cimatti, A.; Brusa, M.</p> <p>2016-10-01</p> <p>To reproduce the properties of galaxies in the local Universe, as well as the scaling relations between host galaxies and black holes properties, many galaxy formation <span class="hlt">models</span> invoke the presence of fast and energetic winds extending over galaxy scales. These massive gas outflows can be powered either by star-formation (SF) or <span class="hlt">AGN</span> activity, though the relative dominance and efficiency of the different mechanisms is not yet fully understoodIn the last decade much effort has been put in the search for observational evidence of such phenomena, especially at the peak of both SF and <span class="hlt">AGN</span> activity through cosmic time (1<z<3), in an attempt to explain the rapid quenching of SF and the link between the evolution of <span class="hlt">AGNs</span> and their host galaxies. Spectroscopy at different wavelengths is the most powerful tool to find and investigate outflows. Blue-shifted inter-stellar medium (ISM) absorption lines in the UV regime, as well as broad, blue-shifted profiles in optical emission lines have been observed in galaxies at all redshifts and are usually interpreted as evidence of fast material moving towards our line of sight. More recently, especially thanks to new facilities like ALMA, outflows are being observed also in neutral and molecular gasIn order to study the differences and possible synergy between the two main driving outflow mechanisms (<span class="hlt">AGN</span> or SF activity) and to understand the role that outflows might play in SF quenching and galaxy evolution, we collected a large sample of <span class="hlt">AGNs</span> and SFGs at z>1.7 from large optical spectroscopic surveys (zCOSMOS, VUDS, ESO public surveys), complemented with HST imaging, X-ray (Chandra) and IR data. The richness of available data for our sample allowed us to map a large portion of the physical parameters space. We concentrated our analysis on the ISM absorption lines in the rest-frame UV wavelength range. Through stacking tecniques we studied the relation between such lines and <span class="hlt">AGN</span> and SFG properties. I will present our results (Talia et al</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010adap.prop..177S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010adap.prop..177S"><span>Ultra-Fast Outflows in Radio-Loud <span class="hlt">AGN</span>: New Constraints on Jet-Disk Connection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sambruna, Rita</p> <p></p> <p>There is strong observational and theoretical evidence that outflows/jets are coupled to accretion disks in black hole accreting systems, from Galactic to extragalactic sizes. While in radio-quiet <span class="hlt">AGN</span> there is ample evidence for the presence of Ultra-Fast Outflows (UFOs) from the presence of blue-shifted absorption features in their 4-10~keV spectra, sub-relativistic winds are expected on theoretical basis in radio-loud <span class="hlt">AGN</span> but have not been observed until now. Our recent Suzaku observations of 5 bright Broad- Line Radio Galaxies (BLRGs, the radio-loud counterparts of Seyferts) has started to change this picture. We found strong evidence for UFOs in 3 out of 5 BLRGs, with ionization parameters, column densities, and velocities of the absorber similar to Seyferts. Moreover, the outflows in BLRGs are likely to be energetically very significant: from the Suzaku data of the three sources, outflow masses similar to the accretion masses and kinetic energies of the wind similar to the X-ray luminosity and radio power of the jet are inferred. Clearly, UFOs in radio-loud <span class="hlt">AGN</span> represent a new key ingredient to understand their central engines and in particular, the jet-disk linkage. Our discovery of UFOs in a handful of BLRGs raises the questions of how common disk winds are in radio-loud <span class="hlt">AGN</span>, what the absorber physical and dynamical characteristics are, and what is the outflow role in broader picture of galaxy-black hole connection for radio sources, i.e., for large-scale feedback <span class="hlt">models</span>. To address these and other issues, we propose to use archival XMM-Newton and Suzaku spectra to search for Ultra-Fast Outflows in a large number of radio sources. Over a period of two years, we will conduct a systematic, uniform analysis of the archival X-ray data, building on our extensive experience with a similar previous project for Seyferts, and using robust analysis and statistical methodologies. As an important side product, we will also obtain accurate, self- consistent measurements</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007Ap%26SS.310...93T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007Ap%26SS.310...93T"><span>Neutrino radiation of the <span class="hlt">AGN</span> black holes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ter-Kazarian, G.; Shidhani, S.; Sargsyan, L.</p> <p>2007-07-01</p> <p>In the framework of ‘microscopic’ theory of black holes (J. Phys. Soc. Jpn. Suppl. B 70, 84, 2001; Astrophys. USSR 4, 659, 1996; 35, 335, 1991, 33, 143, 1990, 31, 345, 1989a; Astrophys. Space Sci. 1, 1992; Dokl. Akad. Nauk USSR 309, 97, 1989b), and references therein, we address the ‘pre-radiation time’ (PRT) of neutrinos from black holes, which implies the lapse of time from black hole’s birth till radiation of an extremely high energy neutrinos. For post-PRT lifetime, the black hole no longer holds as a region of spacetime that cannot communicate with the external universe. We study main features of spherical accretion onto central BH and infer a mass accretion rate onto it, and, further, calculate the resulting PRT versus bolometric luminosity due to accretion onto black hole. We estimate the PRTs of <span class="hlt">AGN</span> black holes, with the well-determined masses and bolometric luminosities, collected from the literature by Woo Jong-Hak and Urry (Astrophys. J. 579, 530, 2002) on which this paper is partially based. The simulations for the black holes of masses M BH ≃(1.1ṡ106 ÷4.2ṡ109) M ⊙ give the values of PRTs varying in the range of about T BH ≃(4.3ṡ105 ÷5.6ṡ1011) yr. The derived PRTs for the 60 <span class="hlt">AGN</span> black holes are longer than the age of the universe (˜13.7 Gyr) favored today. At present, some of remaining 174 BHs may radiate neutrinos. However, these results would be underestimated if the reservoir of gas for accretion in the galaxy center is quite modest, and no obvious way to feed the BHs with substantial accretion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015toru.conf..F04R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015toru.conf..F04R"><span>Key Radio <span class="hlt">Unification</span> Steps Before 1980 and Some Related Recent Radio Observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Readhead, A.</p> <p>2015-09-01</p> <p>Early radio work on <span class="hlt">unification</span> culminated in the first VLBI images using closure phases as well as visibility amplitudes (1976-1979), which (i) convinced even the skeptics of the reality of superluminal motion; (ii) showed that the nuclear structures in both quasars and radio galaxies are one-sided jets, with the jets in radio galaxies aligned with the outer lobes and quasar jets usually strongly curved; (iii) showed that in radio galaxies the nuclear and outer jets (where present) point in the same direction; and (iv) explained the existence of the two populations of steep spectrum extended and flat spectrum compact radio sources by ascribing all these observational effects to orientation relative to the jet axis -- i.e. to projection and relativistic beaming effects. Curiously this early <span class="hlt">unification</span> work in the radio has been overlooked in most <span class="hlt">unification</span> discussions even though it preceded the observations of broad lines in polarized emission from galaxies, which provided strong evidence for the torus. The early radio <span class="hlt">unification</span> work will be briefly reviewed and some interesting developments in radio <span class="hlt">unification</span> of the last few years will be presented and discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApJ...833...60R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApJ...833...60R"><span>The Role of Star Formation and <span class="hlt">AGN</span> in Dust Heating of z=0.3-2.8 Galaxies - II. Informing IR <span class="hlt">AGN</span> Fraction Estimates through Simulations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Roebuck, Eric; Sajina, Anna; Hayward, Christopher C.; Pope, Alexandra; Kirkpatrick, Allison; Hernquist, Lars; Yan, Lin</p> <p>2016-12-01</p> <p>A key question in extragalactic studies is the determination of the relative roles of stars and active galactic nuclei (<span class="hlt">AGNs</span>) in powering dusty galaxies at z ˜ 1-3 where the bulk of star formation and <span class="hlt">AGN</span> activity took place. In Paper I, we present a sample of 336 24 μm selected (Ultra)Luminous Infrared Galaxies, (U)LIRGs, at z˜ 0.3-2.8, where we focus on determining the <span class="hlt">AGN</span> contribution to the IR luminosity. Here, we use hydrodynamic simulations with dust radiative transfer of isolated and merging galaxies to investigate how well the simulations reproduce our empirical IR <span class="hlt">AGN</span> fraction estimates and determine how IR <span class="hlt">AGN</span> fractions relate to the UV-mm <span class="hlt">AGN</span> fraction. We find that: (1) IR <span class="hlt">AGN</span> fraction estimates based on simulations are in qualitative agreement with the empirical values when host reprocessing of the <span class="hlt">AGN</span> light is considered; (2) for star-forming galaxy (SFG)-<span class="hlt">AGN</span> composites our empirical methods may be underestimating the role of <span class="hlt">AGN</span>, as our simulations imply \\gt 50 % <span class="hlt">AGN</span> fractions, ˜ 3× higher than previous estimates; (3) 6% of our empirically classified SFGs have <span class="hlt">AGN</span> fractions ≳50%. While this is a small percentage of SFGs, if confirmed it would imply that the true number density of <span class="hlt">AGNs</span> may be underestimated; (4) this comparison depends on the adopted <span class="hlt">AGN</span> template—those that neglect the contribution of warm dust lower the empirical fractions by up to two times; and (5) the IR <span class="hlt">AGN</span> fraction is only a good proxy for the intrinsic UV-mm <span class="hlt">AGN</span> fraction when the extinction is high ({A}V≳ 1 or up to and including coalescence in a merger).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016agnt.confE..29D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016agnt.confE..29D"><span><span class="hlt">AGN</span> STORM: A Leap Forward In Reverberation Mapping</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dalla Bontà, Elena; AGN STORM Team</p> <p>2016-10-01</p> <p>Reverberation mapping is a tomographic technique that can be used to determine the structure and kinematics of the broad- line emitting region at the center of active galactic nuclei. By-products of these investigations are the masses of the central black holes and information about the structure of the accretion disk. I will show some of the most recent results from the <span class="hlt">AGN</span> Space Telescope and Optical Reverberation Mapping (<span class="hlt">AGN</span> STORM) project, which was built around 180 daily observations of the bright Seyfert 1 galaxy NGC 5548 with the Cosmic Origins Spectrograph on Hubble Space Telescope. <span class="hlt">AGN</span> STORM included observations made with Swift, XMM, and several ground-based telescopes, including the 1.22-m telescope at Asiago Observatory. Elena Dalla Bonta` on behalf of the <span class="hlt">AGN</span> STORM Team.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20060029783&hterms=lensing&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dlensing','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20060029783&hterms=lensing&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dlensing"><span><span class="hlt">AGN</span>-selected clusters as revealed by weak lensing</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wold, M.; Lacy, M.; Dahle, H.; Lilje, P. B.; Ridgway, S. E.</p> <p>2002-01-01</p> <p>We discuss the results in light of the cooling flow and the merger/interaction scenarios for triggering and fuelling <span class="hlt">AGN</span> in clusters, but find that the data do not point unambiguously to neither of the two.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19980002697','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19980002697"><span>Theoretical and Observational Studies of the Central Engines of <span class="hlt">AGN</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sivron, Ran</p> <p>1995-01-01</p> <p>In Active Galactic Nuclei (<span class="hlt">AGN</span>) the luminosity is so intense that the effect of radiation pressure on a particle may exceed the gravitational attraction. It was shown that when such luminosities are reached, relatively cold (not completely ionized) thermal matter clouds may form in the central engines of <span class="hlt">AGN</span>, where most of the luminosity originates. We show that the spectrum of emission from cold clouds embedded in hot relativistic matter is similar to the observed spectrum. We also show that within the hot relativistic matter, cold matter moves faster than the speed of sound or the Alfven speed, and shocks form. The shocks provide a mechanism by which a localized perturbation can propagate throughout the central engine. The shocked matter can emit the observed luminosity, and can explain the flux and spectral variability. It may also provide an efficient mechanism for the outward transfer of angular momentum and provide the outward flow of winds. With observations from X-ray satellites, emission features from the cold and hot matter may be revealed. Our analysis of X-ray data from the Seyfert 1 galaxy MCG - 6-30-15 over five years using detectors on the Ginga and Rosat satellites, revealed some interesting variable features. A source with hot matter emits non-thermal radiation which is Compton reflected from cold matter and then absorbed by warm (partially ionized) absorbing matter in the first <span class="hlt">model</span>, which can be fit to the data if both the cold and warm absorbers are near the central engine. An alternative <span class="hlt">model</span> in which the emission from the hot matter is partially covered by very warm matter (in which all elements except Iron are mostly ionized) is also successful. In this <span class="hlt">model</span> the cold and warm matter may be at distances of up to 100 times the size of the central engine, well within the region where broad optical lines are produced. The flux variability is more naturally explained by the second <span class="hlt">model</span>. Our results support the existence of cold matter in, or</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20783027','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20783027"><span>Gauge-Higgs <span class="hlt">unification</span> and quark-lepton phenomenology in the warped spacetime</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hosotani, Y.; Noda, S.; Sakamura, Y.; Shimasaki, S.</p> <p>2006-05-01</p> <p>In the dynamical gauge-Higgs <span class="hlt">unification</span> of electroweak interactions in the Randall-Sundrum warped spacetime, the Higgs boson mass is predicted in the range 120-290 GeV, provided that the spacetime structure is determined at the Planck scale. Couplings of quarks and leptons to gauge bosons and their Kaluza-Klein excited states are determined by the masses of quarks and leptons. All quarks and leptons other than top quarks have very small couplings to the Kaluza-Klein excited states of gauge bosons. The universality of weak interactions is slightly broken by magnitudes of 10{sup -8}, 10{sup -6}, and 10{sup -2} for {mu}-e, {tau}-e and t-e, respectively. Yukawa couplings become substantially smaller than those in the standard <span class="hlt">model</span>, by a factor cos(1/2){theta}{sub W} where {theta}{sub W} is the non-Abelian Aharonov-Bohm phase (the Wilson line phase) associated with dynamical electroweak symmetry breaking.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JAGI....7....1R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JAGI....7....1R"><span>The Sigma Cognitive Architecture and System: Towards Functionally Elegant Grand <span class="hlt">Unification</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rosenbloom, Paul S.; Demski, Abram; Ustun, Volkan</p> <p>2016-12-01</p> <p>Sigma (Σ) is a cognitive architecture and system whose development is driven by a combination of four desiderata: grand <span class="hlt">unification</span>, generic cognition, functional elegance, and sufficient efficiency. Work towards these desiderata is guided by the graphical architecture hypothesis, that key to progress on them is combining what has been learned from over three decades' worth of separate work on cognitive architectures and graphical <span class="hlt">models</span>. In this article, these four desiderata are motivated and explained, and then combined with the graphical architecture hypothesis to yield a rationale for the development of Sigma. The current state of the cognitive architecture is then introduced in detail, along with the graphical architecture that sits below it and implements it. Progress in extending Sigma beyond these architectures and towards a full cognitive system is then detailed in terms of both a systematic set of higher level cognitive idioms that have been developed and several virtual humans that are built from combinations of these idioms. Sigma as a whole is then analyzed in terms of how well the progress to date satisfies the desiderata. This article thus provides the first full motivation, presentation and analysis of Sigma, along with a diversity of more specific results that have been generated during its development.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20080037784&hterms=Bats&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DBats','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20080037784&hterms=Bats&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DBats"><span>Broad Band Properties of the BAT Selected <span class="hlt">AGN</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mushotzky, Richard; Winter, Lisa; Tueller, jack</p> <p>2008-01-01</p> <p>We will present the x-ray spectral properties of approximately 150 Burst Alert Telescope (BAT) selected active galactic nuclei (<span class="hlt">AGN</span>) focusing on the issues of spectral complexity, x-ray absorption and its distribution and that contribution of sources to the x-ray background. If time permits we will also present the nature of the host galaxies of the <span class="hlt">AGN</span> and their relationship to merger candidates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AAS...22724325M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AAS...22724325M"><span>Combining Chandra Observations and Near-Infrared Imaging to Search for Dual <span class="hlt">AGNs</span> Among Double-Peaked [O III] SDSS <span class="hlt">AGN</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McGurk, Rosalie C.; Max, Claire E.; Holden, Bradford; Shields, Gregory A.; Medling, Anne</p> <p>2016-01-01</p> <p>When galaxies merge, gas accretes onto both central supermassive black holes. Thus, one expects to see close pairs of active galactic nuclei (<span class="hlt">AGNs</span>), or dual <span class="hlt">AGNs</span>, in a fraction of galaxy mergers. However, finding them remains a challenge. We studied a sample of double-peaked SDSS [O III] <span class="hlt">AGNs</span> using Keck 2 Laser Guide Star Adaptive Optics assisted imaging to find that 30% of double-peaked SDSS <span class="hlt">AGNs</span> have two spatial components within a 3" radius. However, the identity of the companion object is not revealed with imaging; X-ray observations can confirm these galaxy pairs as systems containing two <span class="hlt">AGNs</span>. We performed Chandra X-ray ACIS-S observations on 12 double-peaked candidate dual <span class="hlt">AGNs</span> with a possible near-infrared companion 1-3" away. Using our observations and 8 archival observations of additional candidate dual <span class="hlt">AGNs</span>, we compare the distribution of X-ray photons to our spatially double near-IR images, measure X-ray luminosities and hardness ratios, and estimate column densities. Additionally, we can compare our near-IR spatially double candidates with 7 double-peaked [O III] SDSS <span class="hlt">AGNs</span> that are spatially single in our near-IR imaging and have archival Chandra ACIS-S observations. By assessing what fraction of double- peaked emission line SDSS <span class="hlt">AGNs</span> are true dual <span class="hlt">AGNs</span>, we can better determine whether double-peaked [O III] is an efficient dual <span class="hlt">AGN</span> indicator and constrain the statistics of dual <span class="hlt">AGNs</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930014928','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930014928"><span>Modernization and <span class="hlt">unification</span>: Strategic goals for NASA STI program</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Blados, W.; Cotter, Gladys A.</p> <p>1993-01-01</p> <p>Information is increasingly becoming a strategic resource in all societies and economies. The NASA Scientific and Technical Information (STI) Program has initiated a modernization program to address the strategic importance and changing characteristics of information. This modernization effort applies new technology to current processes to provide near-term benefits to the user. At the same time, we are developing a long-term modernization strategy designed to transition the program to a multimedia, global 'library without walls.' Notwithstanding this modernization program, it is recognized that no one information center can hope to collect all the relevant data. We see information and information systems changing and becoming more international in scope. We are finding that many nations are expending resources on national systems which duplicate each other. At the same time that this duplication exists, many useful sources of aerospace information are not being collected because of resource limitations. If nations cooperate to develop an international aerospace information system, resources can be used efficiently to cover expanded sources of information. We must consider forming a coalition to collect and provide access to disparate, multidisciplinary sources of information, and to develop standardized tools for documenting and manipulating this data and information. In view of recent technological developments in information science and technology, as well as the reality of scarce resources in all nations, it is time to explore the mutually beneficial possibilities offered by cooperation and international resource sharing. International resources need to be mobilized in a coordinated manner to move us towards this goal. This paper reviews the NASA modernization program and raises for consideration new possibilities for <span class="hlt">unification</span> of the various aerospace database efforts toward a cooperative international aerospace database initiative that can optimize the cost</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013MNRAS.435.1300G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013MNRAS.435.1300G"><span>Improved characterization of intranight optical variability of prominent <span class="hlt">AGN</span> classes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Goyal, Arti; Gopal-Krishna, Wiita, Paul J.; Stalin, C. S.; Sagar, Ram</p> <p>2013-10-01</p> <p>The incidence of intranight optical variability (INOV) is known to differ significantly among different classes of powerful active galactic nuclei (<span class="hlt">AGN</span>). A number of statistical methods have been employed in the literature for testing the presence of INOV in the light curves, sometimes leading to discordant results. In this paper, we compare the INOV characteristics of six prominent classes of <span class="hlt">AGN</span>, as evaluated using three commonly used statistical tests, namely the χ2-test, the modified C-test and the F-test, which has recently begun to gain popularity. The <span class="hlt">AGN</span> classes considered are: radio-quiet quasars, radio-intermediate quasars, lobe-dominated quasars, low optical polarization core-dominated quasars, high optical polarization core-dominated quasars and TeV blazars. Our analysis is based on a large body of <span class="hlt">AGN</span> monitoring data, involving 262 sessions of intranight monitoring of a total 77 <span class="hlt">AGN</span>, using 1-2 m class optical telescopes located in India. In order to compare the usefulness of the statistical tests, we have also subjected them to a `sanity check' by comparing the number of false positives yielded by each test with the corresponding statistical prediction. The present analysis is intended to serve as a benchmark for future INOV studies of <span class="hlt">AGN</span> of different classes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080045745','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080045745"><span>Mini-Survey Of SDSS of [OIII] <span class="hlt">AGN</span> With Swift</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Angelini, L.; George, I. M.; Hill, J.; Padgett, C. A.; Mushotzky, R. F.</p> <p>2008-01-01</p> <p>The number of <span class="hlt">AGN</span> and their luminosity distribution are crucial parameters for our understanding of the <span class="hlt">AGN</span> phenomenon. Recent work (e.g. Ferrarese and Merritt 2000) strongly suggests every massive galaxy has a central black hole. However, most of these objects either are not radiating or have been very difficult to detect. We are now in the era of large surveys, and the luminosity function (LF) of <span class="hlt">AGN</span> has been estimated in various ways. In the X-ray band, Chandra and XMM surveys (e.g., Barger et al. 2005; Hasinger, et al. 2005) have revealed that the LF of Hard X-ray selected <span class="hlt">AGN</span> shows a strong luminosity-dependent evolution with a dramatic break towards low L(x) (at al z). This is seen for all types of <span class="hlt">AGN</span>, but is stronger for the broad-line objects (e.g., Steffen et al. 2004). In sharp contrast, the local LF of optically-selected samples shows no such break and no differences between narrow and broad-line objects (Hao et al. 2005). If, as been suggested, hard X-ray and optical emission line can both be fair indicators of <span class="hlt">AGN</span> activity, it is important to first understand how reliable these characteristics are if we hope to understand the apparent discrepancy in the LFs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MNRAS.465..302M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MNRAS.465..302M"><span>Lyman continuum leaking <span class="hlt">AGN</span> in the SSA22 field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Micheva, Genoveva; Iwata, Ikuru; Inoue, Akio K.</p> <p>2017-02-01</p> <p>Subaru/SuprimeCam narrow-band photometry of the SSA22 field reveals the presence of four Lyman continuum (LyC) candidates among a sample of 14 active galactic nuclei (<span class="hlt">AGNs</span>). Two show offsets and likely have stellar LyCin nature or are foreground contaminants. The remaining two LyC candidates are type I <span class="hlt">AGN</span>. We argue that the average LyC escape fraction of high-redshift, low-luminosity <span class="hlt">AGN</span> is not likely to be unity, as often assumed in the literature. From direct measurement we obtain the average LyC-to-UV flux density ratio and ionizing emissivity for a number of <span class="hlt">AGN</span> classes and find it at least a factor of 2 lower than values obtained assuming fesc = 1. Comparing to recent Ly α forest measurements, <span class="hlt">AGNs</span> at redshift z ˜ 3 make up at most ˜12 per cent and as little as ˜5 per cent of the total ionizing budget. Our results suggest that <span class="hlt">AGNs</span> are unlikely to dominate the ionization budget of the Universe at high redshifts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22363990','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22363990"><span>YOUNG <span class="hlt">AGN</span> OUTBURST RUNNING OVER OLDER X-RAY CAVITIES</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bogdán, Ákos; Van Weeren, Reinout J.; Kraft, Ralph P.; Forman, William R.; Randall, Scott; Jones, Christine; Giacintucci, Simona; Churazov, Eugene; O'Dea, Christopher P.; Baum, Stefi A.; Noell-Storr, Jacob</p> <p>2014-02-20</p> <p>Although the energetic feedback from active galactic nuclei (<span class="hlt">AGNs</span>) is believed to have a profound effect on the evolution of galaxies and clusters of galaxies, details of <span class="hlt">AGN</span> heating remain elusive. Here, we study NGC 193—a nearby lenticular galaxy—based on X-ray (Chandra) and radio (Very Large Array and Giant Meter-wave Radio Telescope) observations. These data reveal the complex <span class="hlt">AGN</span> outburst history of the galaxy: we detect a pair of inner X-ray cavities, an outer X-ray cavity, a shock front, and radio lobes extending beyond the inner cavities. We suggest that the inner cavities were produced ∼78 Myr ago by a weaker <span class="hlt">AGN</span> outburst, while the outer cavity, the radio lobes, and the shock front are due to a younger (13-26 Myr) and 4-8 times more powerful outburst. Combining this with the observed morphology of NGC 193, we conclude that NGC 193 likely represents the first example of a second, more powerful, <span class="hlt">AGN</span> outburst overrunning an older, weaker outburst. These results help us to understand how the outburst energy is dissipated uniformly in the core of galaxies, and therefore may play a crucial role in resolving how <span class="hlt">AGN</span> outbursts suppress the formation of large cooling flows at cluster centers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015IAUGA..2257168B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015IAUGA..2257168B"><span>Young <span class="hlt">AGN</span> Outburst Running over Older X-Ray Cavities</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bogdan, Akos; van Weeren, Reinout Johannes; Kraft, Ralph; Forman, William; Scott, Randall; Giacintucci, Simona; Churazov, Eugene; O'Dea, Christopher; Baum, Stefi; Noell-Storr, Jacob; Jones, Christine</p> <p>2015-08-01</p> <p>Although the energetic feedback from active galactic nuclei (<span class="hlt">AGNs</span>) is believed to have a profound effect on the evolution of galaxies and clusters of galaxies, details of <span class="hlt">AGN</span> heating remain elusive. Here, we study NGC 193 -- a nearby lenticular galaxy in a group -- based on X-ray and radio observations. These data reveal the complex <span class="hlt">AGN</span> outburst history of the galaxy: we detect a pair of inner X-ray cavities, an outer X-ray cavity, a shock front, and radio lobes extending beyond the inner cavities. We suggest that the inner cavities were produced about 78 Myr ago by a weaker <span class="hlt">AGN</span> outburst, while the outer cavity, the radio lobes, and the shock front are due to a younger (13-26 Myr) and 4-8 times more powerful outburst. Combining this with the observed morphology of NGC 193, we conclude that NGC 193 likely represents the first example of a second, more powerful, <span class="hlt">AGN</span> outburst overrunning an older, weaker outburst. These results help us to understand how the outburst energy is dissipated uniformly in the core of galaxies, and therefore may play a crucial role in resolving how <span class="hlt">AGN</span> outbursts suppress the formation of large cooling flows at cluster centers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ebha.confE..11R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ebha.confE..11R"><span>Unwrapping the X-ray Spectra of <span class="hlt">AGN</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reynolds, C.</p> <p>2015-07-01</p> <p>Active galactic nuclei (<span class="hlt">AGN</span>) are complex phenomena. At the heart of an <span class="hlt">AGN</span> is a relativistic accretion disk around the spinning supermassive black hole with a compact, probably pair-regulated, X-ray corona. On larger scales, the outer accretion disk and molecular torus act as the reservoirs of gas for the continuing <span class="hlt">AGN</span> activity. And on all scales from the black hole outwards, powerful winds (and sometimes jets) are seen and can dominate the source energetics. As I shall review in this talk, each of these components imprints its own characteristic signature into the (time-variable) X-ray spectrum of the <span class="hlt">AGN</span>. I shall then touch upon a few contemporary topics : (i) the use of new spectral timing techniques for aiding in the decomposition of the spectrum and for probing the geometry of the <span class="hlt">AGN</span> central engine, (ii) the determination of supermassive black hole spin, (iii) direct confirmation of quasar-mode feedback in some luminous systems. The prospect of <span class="hlt">AGN</span> observations with Astro-H will be discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016agnw.confE..14D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016agnw.confE..14D"><span>Properties and evolution of radio-<span class="hlt">AGN</span> hosts since z~4</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Delvecchio, Ivan</p> <p>2016-08-01</p> <p>We analyse the multi-wavelength properties of about 6200 radio (3-GHz) selected sources in the COSMOS field to investigate the impact of <span class="hlt">AGN</span> activity on the integrated properties of their hosts. Two main classes of <span class="hlt">AGN</span> are identified: radiatively-efficient <span class="hlt">AGN</span>, by combining X-ray, mid-IR diagnostics and SED decomposition, and radiatively-inefficient <span class="hlt">AGN</span>, that show up only in radio. Interestingly, we find significantly distinct galaxy properties for the two <span class="hlt">AGN</span> classes, as a function of redshift. At z<2, radiatively-inefficient <span class="hlt">AGN</span> are typically found in more massive and less star-forming galaxies than radiatively-efficient <span class="hlt">AGN</span>, while at higher redshift we observe a possible reversal of their stellar mass distributions. We interpret these trends in the context of the anti-hierarchical growth of <span class="hlt">AGN</span> host galaxies, with a particular focus on the role of <span class="hlt">AGN</span> feedback over cosmic time in radio-selected samples.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016agnt.confE..15D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016agnt.confE..15D"><span>Properties And Evolution Of Radio-<span class="hlt">AGN</span> Hosts Since z ~ 4</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Delvecchio, Ivan; Smolčić, V.; Zamorani, G.; Del P. Lagos, C.; Berta, S.; Delhaize, J.; Baran, N.; Alexander, D.; Rosario, D.; et al.</p> <p>2016-10-01</p> <p>We analyse the multi-wavelength properties of about 7500 radio (3-GHz) selected sources in the COSMOS field to investigate the impact of <span class="hlt">AGN</span> activity on the integrated properties of their hosts. Two main classes of <span class="hlt">AGN</span> are identified: radiatively- efficient <span class="hlt">AGN</span>, by combining X-ray, mid-IR diagnostics and SED decomposition, and radiatively-inefficient <span class="hlt">AGN</span>, that show up only in radio. Interestingly, we find significantly distinct galaxy properties for the two <span class="hlt">AGN</span> classes, as a function of redshift. At z<1.5, radiatively-inefficient <span class="hlt">AGN</span> are typically found in more massive and less star-forming galaxies than radiatively-efficient <span class="hlt">AGN</span>, while at higher redshift we observe a possible reversal of their stellar mass distributions. We interpret these trends in the context of the anti-hierarchical growth of <span class="hlt">AGN</span> host galaxies, with a particular focus on the role of <span class="hlt">AGN</span> feedback over cosmic time in radio-selected samples.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MNRAS.465.4872G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MNRAS.465.4872G"><span>Hiding in plain sight - recovering clusters of galaxies with the strongest <span class="hlt">AGN</span> in their cores</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Green, T. S.; Edge, A. C.; Ebeling, H.; Burgett, W. S.; Draper, P. W.; Kaiser, N.; Kudritzki, R.-P.; Magnier, E. A.; Metcalfe, N.; Wainscoat, R. J.; Waters, C.</p> <p>2017-03-01</p> <p>A key challenge in understanding the feedback mechanism of active galactic nucleus (<span class="hlt">AGN</span>) in Brightest Cluster Galaxies (BCGs) is the inherent rarity of catching an <span class="hlt">AGN</span> during its strong outburst phase. This is exacerbated by the ambiguity of differentiating between <span class="hlt">AGN</span> and clusters in X-ray observations. If there is evidence for an <span class="hlt">AGN</span> then the X-ray emission is commonly assumed to be dominated by the <span class="hlt">AGN</span> emission, introducing a selection effect against the detection of <span class="hlt">AGN</span> in BCGs. In order to recover these 'missing' clusters, we systematically investigate the colour-magnitude relation around some ∼3500 ROSAT All-Sky Survey selected <span class="hlt">AGN</span>, looking for signs of a cluster red sequence. Amongst our 22 candidate systems, we independently rediscover several confirmed systems, where a strong <span class="hlt">AGN</span> resides in a central galaxy. We compare the X-ray luminosity to red sequence richness distribution of our <span class="hlt">AGN</span> candidate systems with that of a similarly selected comparison sample of ∼1000 confirmed clusters and identify seven 'best' candidates (all of which are BL Lac objects), where the X-ray flux is likely to be a comparable mix between cluster and <span class="hlt">AGN</span> emission. We confirm that the colours of the red sequence are consistent with the redshift of the <span class="hlt">AGN</span>, that the colours of the <span class="hlt">AGN</span> host galaxy are consistent with <span class="hlt">AGN</span>, and, by comparing their luminosities with those from our comparison clusters, confirm that the <span class="hlt">AGN</span> hosts are consistent with BCGs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014OptLE..55..189L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014OptLE..55..189L"><span>A practical coordinate <span class="hlt">unification</span> method for integrated tactile-optical measuring system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Feng; Peter Longstaff, Andrew; Fletcher, Simon; Myers, Alan</p> <p>2014-04-01</p> <p>To meet the requirement of both high speed and high accuracy 3D measurements for dimensional metrology, multi-sensor measuring systems have been developed to measure, analyse and reverse engineer the geometry of objects. This paper presents a new development in coordinate <span class="hlt">unification</span> called the "centroid of spherical centres" method, which can be used instead of the traditional method which uses three datum-points to perform the geometric transformation and <span class="hlt">unification</span> of tactile and optical sensors. The benefits of the proposed method are improved accuracy in coordinate <span class="hlt">unification</span> and the method is used to integrate a coordinate measuring machine (CMM) and optical sensors (structured light scanning system and FaroArm laser line probe). A sphere-plate artefact is developed for data fusion of the multi-sensor system and experimental results validate the accuracy and effectiveness of this method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25666170','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25666170"><span>Fast oscillatory dynamics during language comprehension: <span class="hlt">Unification</span> versus maintenance and prediction?</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lewis, Ashley Glen; Wang, Lin; Bastiaansen, Marcel</p> <p>2015-09-01</p> <p>The role of neuronal oscillations during language comprehension is not yet well understood. In this paper we review and reinterpret the functional roles of beta- and gamma-band oscillatory activity during language comprehension at the sentence and discourse level. We discuss the evidence in favor of a role for beta and gamma in <span class="hlt">unification</span> (the <span class="hlt">unification</span> hypothesis), and in light of mounting evidence that cannot be accounted for under this hypothesis, we explore an alternative proposal linking beta and gamma oscillations to maintenance and prediction (respectively) during language comprehension. Our maintenance/prediction hypothesis is able to account for most of the findings that are currently available relating beta and gamma oscillations to language comprehension, and is in good agreement with other proposals about the roles of beta and gamma in domain-general cognitive processing. In conclusion we discuss proposals for further testing and comparing the prediction and <span class="hlt">unification</span> hypotheses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EPJWC..6800019I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EPJWC..6800019I"><span>Exploring the Use of Enterprise Content Management Systems in <span class="hlt">Unification</span> Types of Organizations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Izza Arshad, Noreen; Mehat, Mazlina; Ariff, Mohamed Imran Mohamed</p> <p>2014-03-01</p> <p>The aim of this paper is to better understand how highly standardized and integrated businesses known as <span class="hlt">unification</span> types of organizations use Enterprise Content Management Systems (ECMS) to support their business processes. Multiple case study approach was used to study the ways two <span class="hlt">unification</span> organizations use their ECMS in their daily work practices. Arising from these case studies are insights into the differing ways in which ECMS is used to support businesses. Based on the comparisons of the two cases, this study proposed that <span class="hlt">unification</span> organizations may use ECMS in four ways, for: (1) collaboration, (2) information sharing that supports a standardized process structure, (3) building custom workflows that support integrated and standardized processes, and (4) providing links and access to information systems. These findings may guide organizations that are highly standardized and integrated in fashion, to achieve their intended ECMS-use, to understand reasons for ECMS failures and underutilization and to exploit technologies investments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1813573V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1813573V"><span>GOCE-based height system <span class="hlt">unification</span> between Greece and Turkey. First considerations over marine and land areas</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vergos, Georgios S.; Erol, Bihter; Natsiopoulos, Dimitrios A.; Grigoriadis, Vassilios N.; Serkan Işık, Mustafa; Tziavos, Ilias N.</p> <p>2016-04-01</p> <p>The <span class="hlt">unification</span> of local vertical Datums (LVDs) at a country-wide scale has gained significant attention lately, due to the availability of GOCE-based Global Geopotential <span class="hlt">Models</span> (GGMs). The latter, offer unprecedented geoid height accuracies at the 1-1.5 cm level for spherical harmonic expansions to d/o 225-230. Within a single country, several LVDs may be used, especially in the event of islandic nations, therefore the <span class="hlt">unification</span> of all of them to a single nation-wide LVD is of utmost importance. The same holds for neighboring countries, where the <span class="hlt">unification</span> of their vertical datums is necessary as a tool of engineering, cross-border collaboration and environmental and risk management projects. The aforementioned set the main scope of the work carried out in the frame of the present study, which referred to the use of GOCE and GOCE/GRACE GGMs in order to unify the LVDs of Greece and Turkey. It is well-known that the two countries share common borders and are a path for large-scale engineering projects in the energy sector. Therefore, the availability of a common reference for orthometric heights in both countries and/or the determination of the relative offset of their individual zero-level geopotential value poses an emerging issue. The determination of the geopotential value Wo(LVD) for the Greek and Turkish LVDs was first carried out separately for each region performing as well different estimates for the marine area of the Aegean Sea and the terrestrial border-region along eastern Thrace. From that, possible biases of the Hellenic and Turkish LVDs themselves have been drawn and analyzed to determine spatial correlations. Then, the relative offset between the two LVDs was determined employing GPS/Levelling data for both areas and the latest GO-DIR-R5, GO-TIM-R5 and GOCO05s <span class="hlt">models</span> as well as EGM2008. The estimation of the mean offset was used to provide as well a direct link between the Greek and Turkish LVDs with the IAG conventional value recently proposed</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApJ...833...35L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApJ...833...35L"><span>Revisiting the Structure and Spectrum of the Magnetic-reconnection-heated Corona in Luminous <span class="hlt">AGNs</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, J. Y.; Qiao, E. L.; Liu, B. F.</p> <p>2016-12-01</p> <p>It is believed that the hard X-ray emission in the luminous active galactic nuclei (<span class="hlt">AGNs</span>) is from the hot corona above the cool accretion disk. However, the formation of the corona is still debated. Liu et al. investigated the spectrum of the corona heated by the reconnection of the magnetic field generated by dynamo action in the thin disk and emerging into the corona as a result of buoyancy instability. In the present paper, we improve this <span class="hlt">model</span> to interpret the observed relation of the hard X-ray spectrum becoming softer at higher accretion rate in luminous <span class="hlt">AGNs</span>. The magnetic field is characterized by {β }0, i.e., the ratio of the sum of gas pressure and radiation pressure to the magnetic pressure in the disk ({β }0=({P}g,d+{P}r,d)/{P}B). Besides, both the intrinsic disk photons and reprocessed photons by the disk are included as the seed photons for inverse Compton scattering. These improvements are crucial for investigating the effect of magnetic field on the accretion disk corona when it is not clear whether the radiation pressure or gas pressure dominates in the thin disk. We change the value of {β }0 in order to constrain the magnetic field in the accretion disk in luminous <span class="hlt">AGNs</span>. We find that the energy fraction released in the corona (f) gradually increases with the decrease of {β }0 for the same accretion rate. When {β }0 decreases to less than 50, the structure and spectrum of the disk corona are independent of accretion rate, which is similar to the hard spectrum found in Liu et al. Comparing with the observational results of the hard X-ray bolometric correction factor in a sample of luminous <span class="hlt">AGNs</span>, we suggest that the value of {β }0 is about 100-200 for α = 0.3, and the energy fraction f should be larger than 30% for hard X-ray emission.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120016056','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120016056"><span>Evidence for Ultra-Fast Outflows in Radio-Quiet <span class="hlt">AGNs</span>: III - Location and Energetics</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tombesi, F.; Cappi, M.; Reeves, J. N.; Braito, V.</p> <p>2012-01-01</p> <p>Using the results of a previous X-ray photo-ionization <span class="hlt">modelling</span> of blue-shifted Fe K absorption lines on a sample of 42 local radio-quiet <span class="hlt">AGNs</span> observed with XMM-Newton, in this letter we estimate the location and energetics of the associated ultrafast outflows (UFOs). Due to significant uncertainties, we are essentially able to place only lower/upper limits. On average, their location is in the interval approx.0.0003-0.03pc (approx.10(exp 2)-10(exp 4)tau(sub s) from the central black hole, consistent with what is expected for accretion disk winds/outflows. The mass outflow rates are constrained between approx.0.01- 1 Stellar Mass/y, corresponding to approx. or >5-10% of the accretion rates. The average lower-upper limits on the mechanical power are logE(sub K) approx. or = 42.6-44.6 erg/s. However, the minimum possible value of the ratio between the mechanical power and bolometric luminosity is constrained to be comparable or higher than the minimum required by simulations of feedback induced by winds/outflows. Therefore, this work demonstrates that UFOs are indeed capable to provide a significant contribution to the <span class="hlt">AGN</span> r.osmological feedback, in agreement with theoretical expectations and the recent observation of interactions between <span class="hlt">AGN</span> outflows and the interstellar medium in several Seyferts galaxies .</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012MNRAS.422L...1T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012MNRAS.422L...1T"><span>Evidence for ultrafast outflows in radio-quiet <span class="hlt">AGNs</span> - III. Location and energetics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tombesi, F.; Cappi, M.; Reeves, J. N.; Braito, V.</p> <p>2012-05-01</p> <p>Using the results of a previous X-ray photoionization <span class="hlt">modelling</span> of blueshifted Fe K absorption lines on a sample of 42 local radio-quiet <span class="hlt">AGNs</span> observed with XMM-Newton, in this Letter we estimate the location and energetics of the associated ultrafast outflows (UFOs). Due to significant uncertainties, we are essentially able to place only lower/upper limits. On average, their location is in the interval ˜0.0003-0.03 pc (˜ 102-104rs) from the central black hole, consistent with what is expected for accretion disc winds/outflows. The mass outflow rates are constrained between ˜0.01 and 1 M⊙ yr-1, corresponding to >rsim5-10 per cent of the accretion rates. The average lower/upper limits on the mechanical power are log? 42.6-44.6 erg s-1. However, the minimum possible value of the ratio between the mechanical power and bolometric luminosity is constrained to be comparable or higher than the minimum required by simulations of feedback induced by winds/outflows. Therefore, this work demonstrates that UFOs are indeed capable to provide a significant contribution to the <span class="hlt">AGN</span> cosmological feedback, in agreement with theoretical expectations and the recent observation of interactions between <span class="hlt">AGN</span> outflows and the interstellar medium in several Seyfert galaxies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080046144','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080046144"><span>Constraints on Black Hole Spin in a Sample of Broad Iron Line <span class="hlt">AGN</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Brenneman, Laura W.; Reynolds, Christopher S.</p> <p>2008-01-01</p> <p>We present a uniform X-ray spectral analysis of nine type-1 active galactic nuclei (<span class="hlt">AGN</span>) that have been previously found to harbor relativistically broadened iron emission lines. We show that the need for relativistic effects in the spectrum is robust even when one includes continuum "reflection" from the accretion disk. We then proceed to <span class="hlt">model</span> these relativistic effects in order to constrain the spin of the supermassive black holes in these <span class="hlt">AGN</span>. Our principal assumption, supported by recent simulations of geometrically-thin accretion disks, is that no iron line emission (or any associated Xray reflection features) can originate from the disk within the innermost stable circular orbit. Under this assumption, which tends to lead to constraints in the form of lower limits on the spin parameter, we obtain non-trivial spin constraints on five <span class="hlt">AGN</span>. The spin parameters of these sources range from moderate (a approximates 0.6) to high (a > 0.96). Our results allow, for the first time, an observational constraint on the spin distribution function of local supermassive black holes. Parameterizing this as a power-law in dimensionless spin parameter (f(a) varies as absolute value of (a) exp zeta), we present the probability distribution for zeta implied by our results. Our results suggest 90% and 95% confidence limits of zeta > -0.09 and zeta > -0.3 respectively.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21289588','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21289588"><span>The Effect of Ag and <span class="hlt">Ag+N</span> Ion Implantation on Cell Attachment Properties</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Urkac, Emel Sokullu; Oztarhan, Ahmet; Gurhan, Ismet Deliloglu; Iz, Sultan Gulce; Tihminlioglu, Funda; Oks, Efim; Nikolaev, Alexey; Ila, Daryush</p> <p>2009-03-10</p> <p>Implanted biomedical prosthetic devices are intended to perform safely, reliably and effectively in the human body thus the materials used for orthopedic devices should have good biocompatibility. Ultra High Molecular Weight Poly Ethylene (UHMWPE) has been commonly used for total hip joint replacement because of its very good properties. In this work, UHMWPE samples were Ag and <span class="hlt">Ag+N</span> ion implanted by using the Metal-Vapor Vacuum Arc (MEVVA) ion implantation technique. Samples were implanted with a fluency of 1017 ion/cm2 and extraction voltage of 30 kV. Rutherford Backscattering Spectrometry (RBS) was used for surface studies. RBS showed the presence of Ag and N on the surface. Cell attachment properties investigated with <span class="hlt">model</span> cell lines (L929 mouse fibroblasts) to demonstrate that the effect of Ag and <span class="hlt">Ag+N</span> ion implantation can favorably influence the surface of UHMWPE for biomedical applications. Scanning electron microscopy (SEM) was used to demonstrate the cell attachment on the surface. Study has shown that <span class="hlt">Ag+N</span> ion implantation represents more effective cell attachment properties on the UHMWPE surfaces.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012A%26A...546A..58R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012A%26A...546A..58R"><span>GOODS-Herschel: ultra-deep XMM-Newton observations reveal <span class="hlt">AGN</span>/star-formation connection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rovilos, E.; Comastri, A.; Gilli, R.; Georgantopoulos, I.; Ranalli, P.; Vignali, C.; Lusso, E.; Cappelluti, N.; Zamorani, G.; Elbaz, D.; Dickinson, M.; Hwang, H. S.; Charmandaris, V.; Ivison, R. J.; Merloni, A.; Daddi, E.; Carrera, F. J.; Brandt, W. N.; Mullaney, J. R.; Scott, D.; Alexander, D. M.; Del Moro, A.; Morrison, G.; Murphy, E. J.; Altieri, B.; Aussel, H.; Dannerbauer, H.; Kartaltepe, J.; Leiton, R.; Magdis, G.; Magnelli, B.; Popesso, P.; Valtchanov, I.</p> <p>2012-10-01</p> <p><span class="hlt">Models</span> of galaxy evolution assume some connection between the <span class="hlt">AGN</span> and star formation activity in galaxies. We use the multi-wavelength information of the CDFS to assess this issue. We select the <span class="hlt">AGNs</span> from the 3 Ms XMM-Newton survey and measure the star-formation rates of their hosts using data that probe rest-frame wavelengths longward of 20 μm, predominantly from deep 100 μm and 160 μm Herschel observations, but also from Spitzer-MIPS-70 μm. Star-formation rates are obtained from spectral energy distribution fits, identifying and subtracting an <span class="hlt">AGN</span> component. Our sample consists of sources in the z ≈ 0.5-4 redshift range, with star-formation rates SFR ≈ 101-103 M⊙ yr-1 and stellar masses M⋆ ≈ 1010-1011.5 M⊙. We divide the star-formation rates by the stellar masses of the hosts to derive specific star-formation rates (sSFR) and find evidence for a positive correlation between the <span class="hlt">AGN</span> activity (proxied by the X-ray luminosity) and the sSFR for themost active systems with X-ray luminosities exceeding Lx ≃ 1043 erg s-1 and redshifts z ≳ 1. We do not find evidence for such a correlation for lower luminosity systems or those at lower redshifts, consistent with previous studies. We do not find any correlation between the SFR (or the sSFR) and the X-ray absorption derived from high-quality XMM-Newton spectra either, showing that the absorption is likely to be linked to the nuclear region rather than the host, while the star-formation is not nuclear. Comparing the sSFR of the hosts to the characteristic sSFR of star-forming galaxies at the same redshift (the so-called "main sequence") we find that the <span class="hlt">AGNs</span> reside mostly in main-sequence and starburst hosts, reflecting the <span class="hlt">AGN</span>-sSFR connection; however the infrared selection might bias this result. Limiting our analysis to the highest X-ray luminosity <span class="hlt">AGNs</span> (X-ray QSOs with Lx > 1044 erg s-1), we find that the highest-redshift QSOs (with z ≳ 2) reside predominantly in starburst hosts, with an average s</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080040874','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080040874"><span>Mini Survey of SDSS [OIII] <span class="hlt">AGN</span> with Swift: Testing the Hypothesis that L(sub [OIII]) Traces <span class="hlt">AGN</span> Luminosity</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2007-01-01</p> <p>The number of <span class="hlt">AGN</span> and their luminosity distribution are crucial parameters for our understanding of the <span class="hlt">AGN</span> phenomenon. Recent work strongly suggests every massive galaxy has a central black hole. However most of these objects either are not radiating or have been very difficult to detect We are now in the era of large surveys, and the luminosity function (LF] of <span class="hlt">AGN</span> has been estimated in various ways. In the X-ray band. Chandra and XMM surveys have revealed that the LF of hard X-ray selected <span class="hlt">AGN</span> shows a strong luminosity-dependent evolution with a dramatic break towards low L(sub x) (at all z). This is seen for all types of <span class="hlt">AGN</span>, but is stronger for the broad-line objects. In sharp contrast, the local LF of optically-selected samples shows no such break and no differences between narrow and broad-line objects. If as been suggested, hard X ray and optical emission line can both can be fair indicators of <span class="hlt">AGN</span> activity, it is important to first understand how reliable these characteristics are if we hope to understand the apparent discrepancy in the LFs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007SIGMA...3..098B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007SIGMA...3..098B"><span>Quantum Gravity: <span class="hlt">Unification</span> of Principles and Interactions, and Promises of Spectral Geometry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Booß-Bavnbek, Bernhelm; Esposito, Giampiero; Lesch, Matthias</p> <p>2007-10-01</p> <p>Quantum gravity was born as that branch of modern theoretical physics that tries to unify its guiding principles, i.e., quantum mechanics and general relativity. Nowadays it is providing new insight into the <span class="hlt">unification</span> of all fundamental interactions, while giving rise to new developments in modern mathematics. It is however unclear whether it will ever become a falsifiable physical theory, since it deals with Planck-scale physics. Reviewing a wide range of spectral geometry from index theory to spectral triples, we hope to dismiss the general opinion that the mere mathematical complexity of the <span class="hlt">unification</span> programme will obstruct that programme.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApJ...826...17G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApJ...826...17G"><span>On the Importance of Very Light Internally Subsonic <span class="hlt">AGN</span> Jets in Radio-mode <span class="hlt">AGN</span> Feedback</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Guo, Fulai</p> <p>2016-07-01</p> <p>Radio-mode active galactic nucleus (<span class="hlt">AGN</span>) feedback plays a key role in the evolution of galaxy groups and clusters. Its physical origin lies in the kiloparsec-scale interaction of <span class="hlt">AGN</span> jets with the intracluster medium. Large-scale jet simulations often initiate light internally supersonic jets with density contrast 0.01 < η < 1. Here we argue for the first time for the importance of very light (η < 0.01) internally subsonic jets. We investigated the shapes of young X-ray cavities produced in a suite of hydrodynamic simulations, and found that bottom-wide cavities are always produced by internally subsonic jets, while internally supersonic jets inflate cylindrical, center-wide, or top-wide cavities. We found examples of real cavities with shapes analogous to those inflated in our simulations by internally subsonic and internally supersonic jets, suggesting a dichotomy of <span class="hlt">AGN</span> jets according to their internal Mach numbers. We further studied the long-term cavity evolution, and found that old cavities resulted from light jets spread along the jet direction, while those produced by very light jets are significantly elongated along the perpendicular direction. The northwestern ghost cavity in Perseus is pancake shaped, providing tentative evidence for the existence of very light jets. Our simulations show that very light internally subsonic jets decelerate faster and rise much slower in the intracluster medium than light internally supersonic jets, possibly depositing a larger fraction of jet energy to cluster cores and alleviating the problem of low coupling efficiencies found previously. The internal Mach number points to the jet’s energy content, and internally subsonic jets are energetically dominated by non-kinetic energy, such as thermal energy, cosmic rays, or magnetic fields.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhDT.......301L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhDT.......301L"><span>A total and polarized infrared flux view of the <span class="hlt">AGN</span> clumpy torus</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lopez Rodriguez, Enrique</p> <p>2013-12-01</p> <p>Magnetohydrodynamical theories consider the torus of Active Galactic Nuclei (<span class="hlt">AGN</span>) to be part of an outflow wind moving away from the central engine. In this framework, the torus is a particular region of the wind, where dusty and optically thick clouds are formed. The outflows are strongly related to the accretion rate and magnetic field strength, which play an important role in the creation, morphology and evolution of the torus. Through infrared (IR) imaging and polarimetry observations, this dissertation (1) searches for signatures of dusty tori in low-luminosity <span class="hlt">AGN</span> (LLAGN); (2) explores the role and strength of magnetic field in the torus; and (3) investigates the nucleus of radio-loud <span class="hlt">AGN</span>. Recent theoretical <span class="hlt">models</span> predicted that LLAGN do not host a Seyfert-like torus, since low-luminosities (<1042 erg s-1 ) cannot sustain the required outflow rate. High-spatial resolution mid-IR (MIR) imaging and nuclear spectral energy distribution of 22 LLAGN reveals different IR characteristics by dividing the sample in terms of the Eddington ratio. These galaxies show a diversity of nuclear morphologies and have a high MIR/X-ray luminosity ratio compared to higher-luminosity <span class="hlt">AGN</span>. Star formation, jets and/or truncated accretion disk can explain the MIR excess. Although several <span class="hlt">models</span> have been made to account for the outflowing dusty winds from the central engine, the magnetic field strength at the position of the torus remains poorly characterized. Through a novel study using near-IR polarimetry, the magnetic field strength in the clumpy torus was estimated. Specifically, if paramagnetic alignment is assumed in the dusty clouds of the torus, the magnetic field strength of the torus of IC5063 is estimated to be in the range of 12--128 mG. Alternatively, Chandrasekhar-Fermi method suggests a lower-limit magnetic field strength of 13 mG. For the archetypical radio-loud <span class="hlt">AGN</span>, Cygnus A, MIR polarimetry using CanariCam on the 10.4-m Gran Telescopio de Canarias revealed a high</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AAS...22910302B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AAS...22910302B"><span>Exploring Quenching, Morphological Transformation and <span class="hlt">AGN</span>-Driven Winds with Simulations of Galaxy Evolution</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brennan, Ryan; CANDELS</p> <p>2017-01-01</p> <p>We present an examination of the spheroid growth and star formation quenching experienced by galaxies since z~3 by studying the evolution with redshift of the quiescent and spheroid-dominated fractions of galaxies from the CANDELS and GAMA surveys. We compare these fractions with predictions from a semi-analytic <span class="hlt">model</span> which includes prescriptions for bulge growth and <span class="hlt">AGN</span> feedback due to mergers and disk instabilities. We then subdivide our population into the four quadrants of the specific star-formation rate (sSFR)-Sersic index plane. We find that the fraction of star forming disks declines steadily while the fraction of quiescent spheroids increases with cosmic time. The fraction of star-forming spheroids and quiescent disks are both non-negligible and remain nearly constant. Our <span class="hlt">model</span> is qualitatively successful at reproducing these fractions, suggesting a plausible explanation for the observed correlations between star formation activity and galaxy structure.Next, we study the correlation of galaxy structural properties with their location relative to the star-formation rate-stellar mass correlation, or the star forming main sequence. We find that as we move from observed galaxies above the main sequence to those below it, we see a nearly monotonic trend towards higher median Sersic index, smaller radius, lower SFR density and higher stellar mass density. Our <span class="hlt">model</span> again qualitatively reproduces these trends, supporting a picture in which bulges and black holes co-evolve and <span class="hlt">AGN</span> feedback plays a critical role in galaxy quenching.Finally, we examine <span class="hlt">AGN</span>-driven winds in a suite of cosmological zoom simulations including a novel mechanical and radiation-driven <span class="hlt">AGN</span> feedback prescription and compare the gas cycle with a matched suite of zoom simulations that include only feedback from supernovae and young stars. We find that while stellar feedback can drive mass out of galaxies, it is unlikely to be able to keep the gas from re-accreting, whereas in our <span class="hlt">AGN</span> runs it</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017hsa9.conf..232S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017hsa9.conf..232S"><span>Probing relativistic effects in the central engine of <span class="hlt">AGN</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sanfrutos, M.; Miniutti, G.</p> <p>2017-03-01</p> <p>Active Galactic Nuclei (<span class="hlt">AGN</span>) are perfect laboratories to check General Relativity (GR) effects by using Broad Line Region (BLR) clouds eclipses to probe the innermost regions of the accretion disk. A new relativistic X–ray spectral <span class="hlt">model</span> for X–ray eclipses is introduced. First we present the different observables that are involved in X–ray eclipses, including the X–ray emitting regions size, the emissivity index, the cloud's column density, ionization, size and velocity, the black hole spin, and the system's inclination. Then we highlight some theoretical predictions on the observables by using XMM–Newton simulations, finding that absorption varies depending on the photons' energy range, being maximum when the approaching side of the X–ray–emitting region is covered. Finally, we fit our relativistic <span class="hlt">model</span> to actual XMM–Newton data from a long observation of the NLS1 galaxy SWIFT J2127.4+5654, and compare our results with a previous work, in which we addressed the BLR cloud eclipse from a non–relativistic prespective.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016HEAD...1511106D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016HEAD...1511106D"><span>Early Results from Swift <span class="hlt">AGN</span> and Cluster Survey</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dai, Xinyu; Griffin, Rhiannon; Nugent, Jenna; Kochanek, Christopher S.; Bregman, Joel N.</p> <p>2016-04-01</p> <p>The Swift <span class="hlt">AGN</span> and Cluster Survey (SACS) uses 125 deg^2 of Swift X-ray Telescope serendipitous fields with variable depths surrounding gamma-ray bursts to provide a medium depth (4 × 10^-15 erg cm^-2 s^-1) and area survey filling the gap between deep, narrow Chandra/XMM-Newton surveys and wide, shallow ROSAT surveys. Here, we present the first two papers in a series of publications for SACS. In the first paper, we introduce our method and catalog of 22,563 point sources and 442 extended sources. SACS provides excellent constraints on the <span class="hlt">AGN</span> and cluster number counts at the bright end with negligible uncertainties due to cosmic variance, and these constraints are consistent with previous measurements. The depth and areal coverage of SACS is well suited for galaxy cluster surveys outside the local universe, reaching z > 1 for massive clusters. In the second paper, we use SDSS DR8 data to study the 203 extended SACS sources that are located within the SDSS footprint. We search for galaxy over-densities in 3-D space using SDSS galaxies and their photometric redshifts near the Swift galaxy cluster candidates. We find 103 Swift clusters with a > 3σ over-density. The remaining targets are potentially located at higher redshifts and require deeper optical follow-up observations for confirmations as galaxy clusters. We present a series of cluster properties including the redshift, BCG magnitude, BCG-to-X-ray center offset, optical richness, X-ray luminosity and red sequences. We compare the observed redshift distribution of the sample with a theoretical <span class="hlt">model</span>, and find that our sample is complete for z ≤ 0.3 and 80% complete for z ≤ 0.4, consistent with the survey depth of SDSS. These analysis results suggest that our Swift cluster selection algorithm presented in our first paper has yielded a statistically well-defined cluster sample for further studying cluster evolution and cosmology. In the end, we will discuss our ongoing optical identification of z>0.5 cluster</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999AAS...195.1904K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999AAS...195.1904K"><span>Spectropolarimetry of <span class="hlt">AGN</span>, and `Women &\\ Science'</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kay, L.</p> <p>1999-12-01</p> <p>I have been using optical spectropolarimetry to investigate the nature of <span class="hlt">AGN</span>. For the CAREER project, I have worked with A. M. Magalhães of the IAG in Brazil to use a visiting polarimetry module with the RC Spectrograph at CTIO, as well as conduct observations at Lick. Projects include observations of broad--line radio galaxies with double--peaked emission line profiles suggestive of accretion disks, and observations of a sample of X-ray selected narrow--line Seyfert 1 galaxies. Another project involves optical and X-ray observations of a complete sample of nearby Seyfert 2 galaxies in order to investigate the frequency of obscured broad--line regions and to determine their contribution to the X-ray background. In addition to involving undergraduate students in research, my educational efforts have focused on getting science into our Women's Studies program. I teach a course on the history and sociology of women in science, co-teach a course on feminist science studies, helped to create a course on women's health, organized a faculty seminar on gender and science issues, and lead a project at Barnard on gender and scientific literacy. I gratefully acknowledge support from NSF CAREER grant AST-9501835, as well as support from NSF International Research Fellowship INT-9423970, and from NSF grant EHR-9555808 to the AAC&U for the Gender and Scientific Literacy project.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015toru.conf..O27O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015toru.conf..O27O"><span>The relative wavelength independence of IR lags in <span class="hlt">AGNs</span>: implications for the distribution of the hot dust</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Oknyansky, V.</p> <p>2015-09-01</p> <p>As seen from the central source, the dusty torus of <span class="hlt">AGNs</span> has a puzzlingly high covering factor. If the torus consists of clouds of dust, each with a relatively unobscured view of the higher energy photons from nearer the center of the <span class="hlt">AGN</span>, the temperature of each dust cloud will fall off as roughly the inverse square root of the radius. Since the dust is heated by the central radiation, in such a <span class="hlt">model</span> the Near and Mid IR lag would increase with the wavelength to a power of 2 to 2.8. We show that, contrary to this simple prediction, for a significant fraction of <span class="hlt">AGNs</span> the lags of the J, H, K, and L bands with respect to the optical show at best only a small difference. This means that rather than there being an extended radial temperature gradient, the hot dust reprocessing the central radiation is effectively in a relatively thin shell. We show that this can be explained by the hot dust being on the surface of a cone that is approximately tangential to the paraboloidal isodelay surface. We note that a number of the <span class="hlt">AGNs</span> showing similar J, H, K, and L lags are also Seyferts that have changed between type 1 and type 2. It is not clear whether this is related or is merely a consequence of these objects being well studied for a long time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002A%26A...396..833R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002A%26A...396..833R"><span>Particle acceleration in rotating and shearing jets from <span class="hlt">AGN</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rieger, F. M.; Mannheim, K.</p> <p>2002-12-01</p> <p>We <span class="hlt">model</span> the acceleration of energetic particles due to shear and centrifugal effects in rotating astrophysical jets. The appropriate equation describing the diffusive transport of energetic particles in a collisionless, rotating background flow is derived and analytical steady state solutions are discussed. In particular, by considering velocity profiles from rigid, over flat to Keplerian rotation, the effects of centrifugal and shear acceleration of particles scattered by magnetic inhomogeneities are distinguished. In the case where shear acceleration dominates, it is confirmed that power law particle momentum solutions f(p) ~ p-(3+alpha ) exist, if the mean scattering time tauc ~ palpha is an increasing function of momentum. We show that for a more complex interplay between shear and centrifugal acceleration, the recovered power law momentum spectra might be significantly steeper but flatten with increasing azimuthal velocity due to the increasing centrifugal effects. The possible relevance of shear and centrifugal acceleration for the observed extended emission in <span class="hlt">AGN</span> is demonstrated for the case of the jet in the quasar 3C273.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011HEAD...12.3918M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011HEAD...12.3918M"><span>Average Heating Rate of Hot Atmospheres in Distant Galaxy Clusters by Radio <span class="hlt">AGN</span>: Evidence for Continuous <span class="hlt">AGN</span> Heating</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ma, Cheng-Jiun; McNamara, B.; Nulsen, P.; Schaffer, R.</p> <p>2011-09-01</p> <p>X-ray observations of nearby clusters and galaxies have shown that energetic feedback from <span class="hlt">AGN</span> is heating hot atmospheres and is probably the principal agent that is offsetting cooling flows. Here we examine <span class="hlt">AGN</span> heating in distant X-ray clusters by cross correlating clusters selected from the 400 Square Degree X-ray Cluster survey with radio sources in the NRAO VLA Sky Survey. The jet power for each radio source was determined using scaling relations between radio power and cavity power determined for nearby clusters, groups, and galaxies with atmospheres containing X-ray cavities. Roughly 30% of the clusters show radio emission above a flux threshold of 3 mJy within the central 250 kpc that is presumably associated with the brightest cluster galaxy. We find no significant correlation between radio power, hence jet power, and the X-ray luminosities of clusters in redshift range 0.1 -- 0.6. The detection frequency of radio <span class="hlt">AGN</span> is inconsistent with the presence of strong cooling flows in 400SD, but cannot rule out the presence of weak cooling flows. The average jet power of central radio <span class="hlt">AGN</span> is approximately 2 10^{44} erg/s. The jet power corresponds to an average heating of approximately 0.2 keV/particle for gas within R_500. Assuming the current <span class="hlt">AGN</span> heating rate remained constant out to redshifts of about 2, these figures would rise by a factor of two. Our results show that the integrated energy injected from radio <span class="hlt">AGN</span> outbursts in clusters is statistically significant compared to the excess entropy in hot atmospheres that is required for the breaking of self-similarity in cluster scaling relations. It is not clear that central <span class="hlt">AGN</span> in 400SD clusters are maintained by a self-regulated feedback loop at the base of a cooling flow. However, they may play a significant role in preventing the development of strong cooling flows at early epochs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22167204','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22167204"><span>CHARACTERIZATION OF A SAMPLE OF INTERMEDIATE-TYPE <span class="hlt">AGNs</span>. I. SPECTROSCOPIC PROPERTIES AND SERENDIPITOUS DISCOVERY OF NEW DUAL <span class="hlt">AGNs</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Benitez, Erika; Cruz-Gonzalez, Irene; Martinez, Benoni; Jimenez-Bailon, Elena; Mendez-Abreu, Jairo; Lopez-Martin, Luis; Fuentes-Carrera, Isaura; Leon-Tavares, Jonathan; Chavushyan, Vahram H.</p> <p>2013-01-20</p> <p>A sample of 10 nearby intermediate-type active galactic nuclei (<span class="hlt">AGNs</span>) drawn from the Sloan Digital Sky Survey is presented. The aim of this work is to provide estimations of the black hole (BH) mass for the sample galaxies from the dynamics of the broad-line region. For this purpose, a detailed spectroscopic analysis of the objects was done. Using Baldwin-Phillips-Terlevich diagnostic diagrams, we have carefully classified the objects as true intermediate-type <span class="hlt">AGNs</span> and found that 80%{sup +7.2%} {sub -17.3%} are composite <span class="hlt">AGNs</span>. The BH mass estimated for the sample is within 6.54 {+-} 0.16 < log M {sub BH} < 7.81 {+-} 0.14. Profile analysis shows that five objects (J120655.63+501737.1, J121607.08+504930.0, J141238.14+391836.5, J143031.18+524225.8, and J162952.88+242638.3) have narrow double-peaked emission lines in both the red (H{alpha}, [N II] {lambda}{lambda}6548,6583 and [S II] {lambda}{lambda}6716, 6731) and the blue (H{beta} and [O III] {lambda}{lambda}4959, 5007) regions of the spectra, with velocity differences ({Delta}V) between the double peaks within 114 km s{sup -1} < {Delta}V < 256 km s{sup -1}. Two of them, J121607.08+504930.0 and J141238.14+391836.5, are candidates for dual <span class="hlt">AGNs</span> since their double-peaked emission lines are dominated by <span class="hlt">AGN</span> activity. In searches of dual <span class="hlt">AGNs</span>, type 1, type II, and intermediate-type <span class="hlt">AGNs</span> should be carefully separated, due to the high serendipitous number of narrow double-peaked sources (50% {+-} 14.4%) found in our sample.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4089931','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4089931"><span><span class="hlt">Unification</span> of multi-species vertebrate anatomy ontologies for comparative biology in Uberon</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2014-01-01</p> <p>Background Elucidating disease and developmental dysfunction requires understanding variation in phenotype. Single-species <span class="hlt">model</span> organism anatomy ontologies (ssAOs) have been established to represent this variation. Multi-species anatomy ontologies (msAOs; vertebrate skeletal, vertebrate homologous, teleost, amphibian AOs) have been developed to represent ‘natural’ phenotypic variation across species. Our aim has been to integrate ssAOs and msAOs for various purposes, including establishing links between phenotypic variation and candidate genes. Results Previously, msAOs contained a mixture of unique and overlapping content. This hampered integration and coordination due to the need to maintain cross-references or inter-ontology equivalence axioms to the ssAOs, or to perform large-scale obsolescence and modular import. Here we present the <span class="hlt">unification</span> of anatomy ontologies into Uberon, a single ontology resource that enables interoperability among disparate data and research groups. As a consequence, independent development of TAO, VSAO, AAO, and vHOG has been discontinued. Conclusions The newly broadened Uberon ontology is a unified cross-taxon resource for metazoans (animals) that has been substantially expanded to include a broad diversity of vertebrate anatomical structures, permitting reasoning across anatomical variation in extinct and extant taxa. Uberon is a core resource that supports single- and cross-species queries for candidate genes using annotations for phenotypes from the systematics, biodiversity, medical, and <span class="hlt">model</span> organism communities, while also providing entities for logical definitions in the Cell and Gene Ontologies. The ontology release files associated with the ontology merge described in this manuscript are available at: http://purl.obolibrary.org/obo/uberon/releases/2013-02-21/ Current ontology release files are available always available at: http://purl.obolibrary.org/obo/uberon/releases/ PMID:25009735</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21607817','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21607817"><span>Collider signatures of the SO(5)xU(1) gauge-Higgs <span class="hlt">unification</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hosotani, Yutaka; Tanaka, Minoru; Uekusa, Nobuhiro</p> <p>2011-10-01</p> <p>Collider signatures of the SO(5)xU(1) gauge-Higgs <span class="hlt">unification</span> <span class="hlt">model</span> in the Randall-Sundrum warped space are explored. Gauge couplings of quarks and leptons receive small corrections from the fifth dimension whose effects are tested by the precision data. It is found that the forward-backward asymmetries in e{sup +}e{sup -} collisions on the Z pole are well explained in a wide range of the warp factor z{sub L}, but the <span class="hlt">model</span> is consistent with the branching fractions of Z decay only for large z{sub L} > or approx. 10{sup 15}. Kaluza-Klein (KK) spectra of gauge bosons, quarks, and leptons as well as gauge and Higgs couplings of low-lying KK excited states are determined. Right-handed quarks and leptons have larger couplings to the KK gauge bosons than left-handed ones. Production rates of Higgs bosons and KK states at the Tevatron, LHC, and International Linear Collider are evaluated. The first KK Z has a mass 1130 GeV with a width 422 GeV for z{sub L}=10{sup 15}. The current limit on the Z' production at the Tevatron and LHC indicates z{sub L}>10{sup 15}. A large effect of parity violation appears in the difference between the rapidity distributions of e{sup +} and e{sup -} in the decay of the first KK Z. The first KK gauge bosons decay into light and heavy quarks evenly.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20070030246&hterms=Wisdom&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DWisdom','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20070030246&hterms=Wisdom&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DWisdom"><span>Mini-Survey of SDSS OIII <span class="hlt">AGN</span> with Swift</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Angelina, Lorella; George, Ian</p> <p>2007-01-01</p> <p>There is a common wisdom that every massive galaxy has a massive block hole. However, most of these objects either are not radiating or until recently have been very difficult to detect. The Sloan Digital Sky Survey (SDSS) data, based on the [OIII] line indicate that perhaps up to 20% of all galaxies may be classified as <span class="hlt">AGN</span> a surprising result that must be checked with independent data. X-ray surveys have revealed that hard X-ray selected <span class="hlt">AGN</span> show a strong luminosity dependent evolution and their luminosity function (LF) shows a dramatic break towards low Lx (at all z). This is seen for all types of <span class="hlt">AGN</span>, but is stronger for the broad-line objects. In sharp contrast, the local LF of (optically-selected samples) shows no such break and no differences between narrow and broad-line objects. Assuming both hard X-ray and [OIII] emission are fair indicators of <span class="hlt">AGN</span> activity, it is important to understand this discrepancy. We present here the results of a mini-survey done with Swift on a selected sample of SDSS selected <span class="hlt">AGN</span>. The objects have been sampled at different L([OIII]) to check the relation with the Lx observed with Swift.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016sofi.prop..167Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016sofi.prop..167Y"><span>Mid-infrared Flux Variability in an Awakening <span class="hlt">AGN</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yeh, Sherry</p> <p></p> <p>We propose FORCAST spectroscopic observations between 8 um to 40 um near the nucleus of NGC 660. NGC 660 underwent an <span class="hlt">AGN</span> outburst 6 years ago, which is an ideal case for studying <span class="hlt">AGN</span> astrophysics in a rather quiecent system. However, this rare event has not yet been monitored. Our immidiate goal is to verify the MIR spectroscipic variabilitiy in NGC 660, and to study the <span class="hlt">AGN</span> effects on dust destruction and ISM. We will compare the FORCAST spectra with the Spitzer IRS spectra (taken before the <span class="hlt">AGN</span> outburst), including dust continuum, PAH emission, and high- and low-ionization emission lines. FORCAST's slit width is a close match to the IRS slit width, allowing a direct comparison of the spectra between FORCAST and IRS. Our single-slit Subaru COMICS spectrum taken after the outburst shows significantly weakened PAH emission and dust continuum, suggesting dust destruction. However, it is difficult to draw robust intepretations due to systematic uncertainties in the Subaru data. If dust destruction is confirmed in the post-outburst FORCAST observaitons, we will evaluate the energy budget using the MIR line ratio diagnostics, with archival X-ray and radio data. We will then propose cadence observations of MGC 660's nucleus to monitor the MIR flux variability, and employ the reverberation mapping technique to study NGC 660's <span class="hlt">AGN</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016agnw.confE..15B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016agnw.confE..15B"><span>Star-forming galaxies versus low- and high-excitation radio <span class="hlt">AGN</span> in the VLA-COSMOS 3GHz Large Project</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Baran, Nikola; Smolcic, Vernesa; Delvecchio, Ivan; Novak, Mladen; Delhaize, Jacinta; Laigle, Clotilde; Ilbert, Olivier; (Vla-)Cosmos Collaboration</p> <p>2016-08-01</p> <p>We study the composition of the faint radio population selected from the VLA-COSMOS 3GHz Large Project, a radio continuum survey performed at 10 cm wavelength. The survey covers the full 2 square degree COSMOS field with mean rms ˜ 2.3 μJy/beam, cataloging 10,899 source components above 5× rms. By combining these radio data with UltraVISTA, optical, nearinfrared, and Spitzer/IRAC mid-infrared data, as well as X-ray data from the Chandra Legacy, Chandra COSMOS surveys, we gain insight into the emission mechanisms within our radio sources out to redshifts of z ˜ 5. From these emission characteristics we classify our sources as star forming galaxies or <span class="hlt">AGN</span>. Using their multi-wavelength properties we further separate the <span class="hlt">AGN</span> into sub-samples dominated by radiatively efficient and inefficient <span class="hlt">AGN</span>, often referred to as high- and low-excitation emission line <span class="hlt">AGN</span>.We compare our method with other results based on fitting of the sources' spectral energy distributions using both galaxy and <span class="hlt">AGN</span> spectral <span class="hlt">models</span>, and those based on the infrared-radio correlation. We study the fractional contributions of these sub-populations down to radio flux levels of ˜10 μJy. We find that at 3 GHz flux densities above ˜400 μJy quiescent, red galaxies, consistent with the low-excitation radio <span class="hlt">AGN</span> class constitute the dominant fraction. Below densities of ˜200 μJy star-forming galaxies begin to constitute the largest fraction, followed by the low-excitation, and X-ray- and IR-identified high-excitation radio <span class="hlt">AGN</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=adult+AND+behaviour+AND+towards+AND+environment&pg=2&id=EJ816132','ERIC'); return false;" href="http://eric.ed.gov/?q=adult+AND+behaviour+AND+towards+AND+environment&pg=2&id=EJ816132"><span>Presidential Address: Social Change and Human Development--Experiences from German <span class="hlt">Unification</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Silbereisen, Rainer K.</p> <p>2005-01-01</p> <p>It is well known that human development is influenced by social change. In particular, as evidenced by research on German <span class="hlt">unification</span>, the rapid change of social institutions can impact on various aspects of behaviour and development. Based on my own research experience in this field, I want to show the necessity for a better interdisciplinary…</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED413752.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED413752.pdf"><span>Humor (High-Speed <span class="hlt">Unification</span> Morphology): A Morphological System for Corpus Analysis.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Proszeky, Gabor</p> <p></p> <p>Humor, a reversible, string-based <span class="hlt">unification</span> approach for lemmatizing and disambiguating language data, has been used for both language corpus analysis and creation of a variety of linguistic software applications such as spell-checking. The system is language-independent, allowing multilingual applications for a variety of language types. Its…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=running+AND+Benefits&pg=3&id=EJ1010253','ERIC'); return false;" href="http://eric.ed.gov/?q=running+AND+Benefits&pg=3&id=EJ1010253"><span>Building a Larger Tent for Public Health: Implications of the SOPHE-AAHE <span class="hlt">Unification</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Goodman, Robert Mark</p> <p>2013-01-01</p> <p>The <span class="hlt">unification</span> of the American Association for Health Education (AAHE) and the Society for Public Health Education (SOPHE) generates a long-desired synergy, a ramping up of our leadership influence in promoting health. It also serves as an ongoing opportunity to reflect on how we synergize the distinct philosophic, scientific, and practical…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AAS...20712703A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AAS...20712703A"><span>Circular Polarization in <span class="hlt">AGNs</span>: Polarity and Spectra</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Aller, M. F.; Aller, H. D.; Plotkin, R. M.</p> <p>2005-12-01</p> <p>Circular polarization (Stokes V) observations potentially provide information on the nature and origin of the underlying magnetic fields in <span class="hlt">AGNs</span>. We have been systematically monitoring a group of sources with detectable circular polarization (V>0.1 percent, a level set by the instrumental polarization of our system) in all 4 Stokes parameters at 8.0 and 4.8 GHz since 2000, and also at 14.5 GHz since November 2003, with the University of Michigan prime focus paraboloid antenna. These data are compared with historical observations obtained with the same instrument at 8.0 and 4.8 GHz extending back to 1978. Specific goals are to study the temporal spectral behavior of Stokes V and its relation to variability in total flux and linear polarization, and to investigate the question of polarity stability on decade-long time scales using data obtained with the same instrumentation and at the same frequencies. The data are consistent with linear-to-circular mode conversion in partially opaque regions of the source. We find examples of polarity changes with time at one or more frequencies associated with outbursts in total flux and linear polarization, and polarity differences within the 3 frequencies at a single epoch in one case, 3C 279. Such behavior argues against the notion that the sign of Stokes V is a simple tracer of the net flow of magnetic energy from the central engine to the jet or an indicator of the direction of rotation of the spinning central black hole/accretion disk via the winding up of the initial seed magnetic field. This work was supported in part by NSF grant AST-0307629 and by funds from the University of Michigan.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004APS..MAR.N7001H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004APS..MAR.N7001H"><span><span class="hlt">Agnes</span> Pockels: Life, Letters and Papers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Helm, Christiane A.</p> <p>2004-03-01</p> <p><span class="hlt">Agnes</span> Pockels (1862 - 1935) was a German woman, whose studies pioneered surface science. She was born in malaria infected North Italy while her father served in the Austrian army. Because he suffered adverse health effects, the family moved in1871 to Braunschweig (North Germany). There, Pockels went to high school. She was interested in science, but formal training was not available for girls. She took on the role of household manager and nurse as her parents' health deteriorated further. Her diary illustrates the difficulties she faced in trying to maintain her own health, the health of her parents and her scientific research at the same time. When Pockels was 18 or 19, she designed a ring tensiometer. Additionally, she found a new method to introduce water-insoluble compounds to the water surface by dissolving them in an organic solvent, and applying drops of the solution. Her surface film balance technique from 1882 is the basis for the method later developed by Langmuir. Since her experimental work was highly original and in a new field, she failed to get it recognized in her own country. When she was 28, she wrote to Lord Rayleigh, since she had read about his recent experiments in surface physics. Rayleigh was so impressed with her experimental methods and results that he had her letter translated from German and published it in Nature (1891). She continued her research on surface films, interactions of solutions and contact angles (more papers, 3 in Nature). Still, she did all experiments at home. With the death of her brother in 1913 and the onset of the war, she retired into private life. Thus she was surprised when she was awarded in her late 60ies with a honorary doctorate by the TU Braunschweig (1932) and the annual prize of the German Colloid Society (1931).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016agnw.confE..20M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016agnw.confE..20M"><span><span class="hlt">AGN</span> variability in the radio band</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Max-Moerbeck, Walter</p> <p>2016-08-01</p> <p>Variability is an important and defining characteristic of <span class="hlt">AGN</span>, that along with their broadband spectral energy distribution make their study interesting and challenging. A complete understanding of the physics of these objects requires monitoring observations over the whole electromagnetic spectrum, and includes studying their properties at a given band and also the relationship between multiple wavelengths. Here we present the main results obtained so far with the ongoing OVRO 40m blazar monitoring program at 15 GHz with twice a week cadence. This program started in mid-2007 and is currently monitoring about 1800 blazars, including most of the bright blazars north of declination -20 degrees. These results include: characterization of the variability in the radio band; its relationship with optical and gamma-ray properties; and its relationship to gamma-ray emission as observed with Fermi-LAT, which can provide constrains on the location of the gamma-ray emission region. We will also discuss our ongoing work on the characterization of radio variability using the power spectral density. For this, we are using 8 years of OVRO 40m data for ~1200 sources, and also F-GAMMA monitoring data taken with the Effelsberg 100m telescope for 60 sources with about monthly cadence monitoring data at 8 frequencies between 2.6 and 43.0 GHz. These studies will provide an improved understanding of blazar variability, a better basis to evaluate the statistics of correlated variability between different emission bands, and a long and consistent record of radio observations to be used in gamma-ray and multi-wavelength investigations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MNRAS.464.1466O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MNRAS.464.1466O"><span>BAT <span class="hlt">AGN</span> Spectroscopic Survey - III. An observed link between <span class="hlt">AGN</span> Eddington ratio and narrow-emission-line ratios</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Oh, Kyuseok; Schawinski, Kevin; Koss, Michael; Trakhtenbrot, Benny; Lamperti, Isabella; Ricci, Claudio; Mushotzky, Richard; Veilleux, Sylvain; Berney, Simon; Crenshaw, D. Michael; Gehrels, Neil; Harrison, Fiona; Masetti, Nicola; Soto, Kurt T.; Stern, Daniel; Treister, Ezequiel; Ueda, Yoshihiro</p> <p>2017-01-01</p> <p>We investigate the observed relationship between black hole mass (MBH), bolometric luminosity (Lbol) and Eddington ratio (λEdd) with optical emission-line ratios ([N II] λ6583/Hα, [S II] λλ6716, 6731/Hα, [O I] λ6300/Hα, [O III] λ5007/Hβ, [Ne III] λ3869/Hβ and He II λ4686/Hβ) of hard X-ray-selected active galactic nuclei (<span class="hlt">AGN</span>) from the BAT <span class="hlt">AGN</span> Spectroscopic Survey. We show that the [N II] λ6583/Hα ratio exhibits a significant correlation with λEdd (RPear = -0.44, p-value = 3 × 10-13, σ = 0.28 dex), and the correlation is not solely driven by MBH or Lbol. The observed correlation between [N II] λ6583/Hα ratio and MBH is stronger than the correlation with Lbol, but both are weaker than the λEdd correlation. This implies that the large-scale narrow lines of <span class="hlt">AGN</span> host galaxies carry information about the accretion state of the <span class="hlt">AGN</span> central engine. We propose that [N II] λ6583/Hα is a useful indicator of Eddington ratio with 0.6 dex of rms scatter, and that it can be used to measure λEdd and thus MBH from the measured Lbol, even for high-redshift obscured <span class="hlt">AGN</span>. We briefly discuss possible physical mechanisms behind this correlation, such as the mass-metallicity relation, X-ray heating, and radiatively driven outflows.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014fysc.confP..67W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014fysc.confP..67W"><span>Disentangling <span class="hlt">AGN</span>-Host Galaxy Interactions with Chandra</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Junfeng</p> <p>2014-11-01</p> <p>The circum-nuclear region in active galaxies is often complex with presence of high excitation gas, collimated radio outflow, and star forming regions, besides the active central supermassive black hole. In Chandra studies of a number of archetypal Seyfert galaxies to investigate <span class="hlt">AGN</span>-host galaxy interaction, we were able to evaluate the mass outflow rate and shock heating by radio jet. For galaxies in the throes of a violent merging event such as NGC6240, we were able to resolve 70MK hot gas surrounding the double nuclei and discovered a large scale soft X-ray halo. The unique resolving power of Chandra also enables more discovery of such dual <span class="hlt">AGN</span> systems and signs of past <span class="hlt">AGN</span> outburst activities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015MNRAS.447...72P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015MNRAS.447...72P"><span>Revealing the X-ray variability of <span class="hlt">AGN</span> with principal component analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Parker, M. L.; Fabian, A. C.; Matt, G.; Koljonen, K. I. I.; Kara, E.; Alston, W.; Walton, D. J.; Marinucci, A.; Brenneman, L.; Risaliti, G.</p> <p>2015-02-01</p> <p>We analyse a sample of 26 active galactic nuclei (<span class="hlt">AGN</span>) with deep XMM-Newton observations, using principal component analysis (PCA) to find <span class="hlt">model</span>-independent spectra of the different variable components. In total, we identify at least 12 qualitatively different patterns of spectral variability, involving several different mechanisms, including five sources which show evidence of variable relativistic reflection (MCG-6-30-15, NGC 4051, 1H 0707-495, NGC 3516 and Mrk 766) and three which show evidence of varying partial covering neutral absorption (NGC 4395, NGC 1365 and NGC 4151). In over half of the sources studied, the variability is dominated by changes in a power-law continuum, both in terms of changes in flux and power-law index, which could be produced by propagating fluctuations within the corona. Simulations are used to find unique predictions for different physical <span class="hlt">models</span>, and we then attempt to qualitatively match the results from the simulations to the behaviour observed in the real data. We are able to explain a large proportion of the variability in these sources using simple <span class="hlt">models</span> of spectral variability, but more complex <span class="hlt">models</span> may be needed for the remainder. We have begun the process of building up a library of different principal components, so that spectral variability in <span class="hlt">AGN</span> can quickly be matched to physical processes. We show that PCA can be an extremely powerful tool for distinguishing different patterns of variability in <span class="hlt">AGN</span>, and that it can be used effectively on the large amounts of high-quality archival data available from the current generation of X-ray telescopes. We will make our PCA code available upon request to the lead author.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010ESSD....2..133V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010ESSD....2..133V"><span>CARINA data synthesis project: pH data scale <span class="hlt">unification</span> and cruise adjustments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Velo, A.; Pérez, F. F.; Lin, X.; Key, R. M.; Tanhua, T.; de La Paz, M.; Olsen, A.; van Heuven, S.; Jutterström, S.; Ríos, A. F.</p> <p>2010-05-01</p> <p>Data on carbon and carbon-relevant hydrographic and hydrochemical parameters from 188 previously non-publicly available cruise data sets in the Artic Mediterranean Seas (AMS), Atlantic Ocean and Southern Ocean have been retrieved and merged to a new database: CARINA (CARbon IN the Atlantic Ocean). These data have gone through rigorous quality control (QC) procedures to assure the highest possible quality and consistency. The data for most of the measured parameters in the CARINA database were objectively examined in order to quantify systematic differences in the reported values. Systematic biases found in the data have been corrected in the data products, three merged data files with measured, calculated and interpolated data for each of the three CARINA regions; AMS, Atlantic Ocean and Southern Ocean. Out of a total of 188 cruise entries in the CARINA database, 59 reported pH measured values. All reported pH data have been unified to the Sea-Water Scale (SWS) at 25 °C. Here we present details of the secondary QC of pH in the CARINA database and the scale <span class="hlt">unification</span> to SWS at 25 °C. The pH scale has been converted for 36 cruises. Procedures of quality control, including crossover analysis between cruises and inversion analysis are described. Adjustments were applied to the pH values for 21 of the cruises in the CARINA dataset. With these adjustments the CARINA database is consistent both internally as well as with the GLODAP data, an oceanographic data set based on the World Hydrographic Program in the 1990s. Based on our analysis we estimate the internal consistency of the CARINA pH data to be 0.005 pH units. The CARINA data are now suitable for accurate assessments of, for example, oceanic carbon inventories and uptake rates, for ocean acidification assessment and for <span class="hlt">model</span> validation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AAS...22711904S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AAS...22711904S"><span>Quenching histories of galaxies and the role of <span class="hlt">AGN</span> feedback</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Smethurst, Rebecca Jane; Lintott, Chris; Simmons, Brooke; Galaxy Zoo Team</p> <p>2016-01-01</p> <p>Two open issues in modern astrophysics are: (i) how do galaxies fully quench their star formation and (ii) how is this affected - or not - by <span class="hlt">AGN</span> feedback? I present the results of a new Bayesian-MCMC analysis of the star formation histories of over 126,000 galaxies across the colour magnitude diagram showing that diverse quenching mechanisms are instrumental in the formation of the present day red sequence. Using classifications from Galaxy Zoo we show that the rate at which quenching can occur is morphologically dependent in each of the blue cloud, green valley and red sequence. We discuss the nature of these possible quenching mechanisms, considering the influence of secular evolution, galaxy interactions and mergers, both with and without black hole activity. We focus particularly on the relationship between these quenched star formation histories and the presence of an <span class="hlt">AGN</span> by using this new Bayesian method to show a population of type 2 <span class="hlt">AGN</span> host galaxies have recently (within 2 Gyr) undergone a rapid (τ < 1 Gyr) drop in their star formation rate. With this result we therefore present the first statistically supported observational evidence that <span class="hlt">AGN</span> feedback is an important mechanism for the cessation of star formation in this population of galaxies. The diversity of this new method also highlights that such rapid quenching histories cannot account fully for all the quenching across the current <span class="hlt">AGN</span> host population. We demonstrate that slower (τ > 2 Gyr) quenching rates dominate for high stellar mass (log10[M*/M⊙] > 10.75) hosts of <span class="hlt">AGN</span> with both early- and late-type morphology. We discuss how these results show that both merger-driven and non-merger processes are contributing to the co-evolution of galaxies and supermassive black holes across the entirety of the colour magnitude diagram.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015A%26A...578A.120L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015A%26A...578A.120L"><span>The most obscured <span class="hlt">AGN</span> in the COSMOS field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lanzuisi, G.; Perna, M.; Delvecchio, I.; Berta, S.; Brusa, M.; Cappelluti, N.; Comastri, A.; Gilli, R.; Gruppioni, C.; Mignoli, M.; Pozzi, F.; Vietri, G.; Vignali, C.; Zamorani, G.</p> <p>2015-06-01</p> <p>Highly obscured active galactic nuclei (<span class="hlt">AGN</span>) are common in nearby galaxies, but are difficult to observe beyond the local Universe, where they are expected to significantly contribute to the black hole accretion rate density. Furthermore, Compton-thick (CT) absorbers (NH ≳ 1024 cm-2) suppress even the hard X-ray (2-10 keV) <span class="hlt">AGN</span> nuclear emission, and therefore the column density distribution above 1024 cm-2 is largely unknown. We present the identification and multi-wavelength properties of a heavily obscured (NH ≳ 1025 cm-2), intrinsically luminous (L2-10 > 1044 erg s-1) <span class="hlt">AGN</span> at z = 0.353 in the COSMOS field. Several independent indicators, such as the shape of the X-ray spectrum, the decomposition of the spectral energy distribution and X-ray/[NeV] and X-ray/6 μm luminosity ratios, agree on the fact that the nuclear emission must be suppressed by a ≳1025 cm-2 column density. The host galaxy properties show that this highly obscured <span class="hlt">AGN</span> is hosted in a massive star-forming galaxy, showing a barred morphology, which is known to correlate with the presence of CT absorbers. Finally, asymmetric and blueshifted components in several optical high-ionization emission lines indicate the presence of a galactic outflow, possibly driven by the intense <span class="hlt">AGN</span> activity (LBol/LEdd = 0.3-0.5). Such highly obscured, highly accreting <span class="hlt">AGN</span> are intrinsically very rare at low redshift, whereas they are expected to be much more common at the peak of the star formation and BH accretion history, at z ~ 2-3. We demonstrate that a fully multi-wavelength approach can recover a sizable sample of such peculiar sources in large and deep surveys such as COSMOS.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014cosp...40E2007M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014cosp...40E2007M"><span>The NuSTAR view of radio-quiet <span class="hlt">AGN</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marinucci, Andrea</p> <p></p> <p>AUTHORS: A. Marinucci and the NuSTAR Team ABSTRACT: The Nuclear Spectroscopic Telescope Array (NuSTAR), thanks to its improved sensitivity in hard X-rays with respect to coded aperture observatories, is providing new and exciting results on radio-quiet <span class="hlt">AGN</span>. In this talk I will present results from the NuSTAR <span class="hlt">AGN</span> Physics program after the first two years of science operations. In particular, measurements of the black hole spin and coronal temperature in nearby sources will be discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApJ...835...27A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApJ...835...27A"><span>The MOSDEF Survey: <span class="hlt">AGN</span> Multi-wavelength Identification, Selection Biases, and Host Galaxy Properties</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Azadi, Mojegan; Coil, Alison L.; Aird, James; Reddy, Naveen; Shapley, Alice; Freeman, William R.; Kriek, Mariska; Leung, Gene C. K.; Mobasher, Bahram; Price, Sedona H.; Sanders, Ryan L.; Shivaei, Irene; Siana, Brian</p> <p>2017-01-01</p> <p>We present results from the MOSFIRE Deep Evolution Field (MOSDEF) survey on the identification, selection biases, and host galaxy properties of 55 X-ray, IR, and optically selected active galactic nuclei (<span class="hlt">AGNs</span>) at 1.4< z< 3.8. We obtain rest-frame optical spectra of galaxies and <span class="hlt">AGNs</span> and use the BPT diagram to identify optical <span class="hlt">AGNs</span>. We examine the uniqueness and overlap of the <span class="hlt">AGNs</span> identified at different wavelengths. There is a strong bias against identifying <span class="hlt">AGNs</span> at any wavelength in low-mass galaxies, and an additional bias against identifying IR <span class="hlt">AGNs</span> in the most massive galaxies. <span class="hlt">AGN</span> hosts span a wide range of star formation rates (SFRs), similar to inactive galaxies once stellar mass selection effects are accounted for. However, we find (at ∼2–3σ significance) that IR <span class="hlt">AGNs</span> are in less dusty galaxies with relatively higher SFR and optical <span class="hlt">AGNs</span> in dusty galaxies with relatively lower SFR. X-ray <span class="hlt">AGN</span> selection does not display a bias with host galaxy SFR. These results are consistent with those from larger studies at lower redshifts. Within star-forming galaxies, once selection biases are accounted for, we find <span class="hlt">AGNs</span> in galaxies with similar physical properties as inactive galaxies, with no evidence for <span class="hlt">AGN</span> activity in particular types of galaxies. This is consistent with <span class="hlt">AGNs</span> being fueled stochastically in any star-forming host galaxy. We do not detect a significant correlation between SFR and <span class="hlt">AGN</span> luminosity for individual <span class="hlt">AGN</span> hosts, which may indicate the timescale difference between the growth of galaxies and their supermassive black holes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017yCat..17890112C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017yCat..17890112C"><span>VizieR Online Data Catalog: Offset <span class="hlt">AGN</span> Candidates (Comerford+, 2014)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Comerford, J. M.; Greene, J. E.</p> <p>2017-03-01</p> <p>Our selection criteria for offset <span class="hlt">AGNs</span> are as follows. In the OSSY catalog (Oh et al. 2011ApJS..195...13O), all forbidden lines are forced to have the same kinematics, while all the Balmer lines are fit with a separate kinematical <span class="hlt">model</span> (e.g., Tremonti et al. 2004ApJ...613..898T). We use the velocities of the forbidden lines, Balmer lines, and stellar absorption features measured in OSSY to derive line-of-sight velocity offsets of the forbidden and Balmer lines relative to the stars. (1 data file).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..1414438G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..1414438G"><span>The Complex Physics of Climate Change and Climate Sensitivity: A Grand <span class="hlt">Unification</span> (Alfred Wegener Medal Lecture)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ghil, M.</p> <p>2012-04-01</p> <p>Recent estimates of climate evolution over the coming century still differ by several degrees. This uncertainty motivates in part the work presented in this lecture. The complex physics of climate change arises from the large number of components of the climate system, as well as from the wealth of processes occurring in each of the components and across them. This complexity has given rise to countless attempts to <span class="hlt">model</span> each component and process, as well as to two overarching approaches to apprehend the complexity as a whole: deterministically nonlinear and stochastically linear. Call them the Ed Lorenz and the Klaus Hasselmann approach, respectively, for short. We propose a "grand <span class="hlt">unification</span>" of these two approaches that relies on the theory of random dynamical systems (RDS). In particular, we apply this theory to the problem of climate sensitivity, and study the random attractors of nonlinear, stochastically perturbed systems, as well as the time-dependent probability densities associated with these attractors. The random attractors so obtained are visually spectacular objects that generalize the strange attractors of the Lorenz approach. Results are presented for several simple climate <span class="hlt">models</span>, from the classical Lorenz convection <span class="hlt">model</span> to El Nino-Southern Oscillation <span class="hlt">models</span>. Their attractors carry probability densities with nice physical properties. Implications of these properties for climate predictability on interannual and decadal time scales are discussed. The RDS setting allows one to examine the interaction of internal climate variability with the forcing, whether natural or anthropogenic, and to provide a definition of climate sensitivity that takes into account the climate system's non-equilibrium behavior. Such a definition is of the essence in studying systematically the sensitivity of global climate <span class="hlt">models</span> (GCMs) to the uncertainties in tens of semi-empirical parameters; it is given here in terms of the response of the appropriate probability</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PASJ...64...37T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PASJ...64...37T"><span>A Method of Identifying <span class="hlt">AGNs</span> Based on Emission-Line Excess and the Nature of Low-Luminosity <span class="hlt">AGNs</span> in the Sloan Digital Sky Survey. II. The Nature of Low-Luminosity <span class="hlt">AGNs</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tanaka, Masayuki</p> <p>2012-04-01</p> <p>We have developed a new method of identifying active galactic nuclei (<span class="hlt">AGNs</span>) and studied the nature of low-luminosity <span class="hlt">AGNs</span> in the Sloan Digital Sky Survey. This is the latter part of a series of papers in which we consider correlations between the <span class="hlt">AGN</span> activities and the host-galaxy properties. Based on a sample of <span class="hlt">AGNs</span> identified by a new method developed in the former part (2012, PASJ, 64, 36), we found that <span class="hlt">AGNs</span> typically show extinction of τV = 1.2, and exhibit a wide range of ionization levels. The finding of ionization levels motivated us to use [O II] + [O III] as an indicator of <span class="hlt">AGN</span> power. We found that <span class="hlt">AGNs</span> are preferentially located in massive, red, early-type galaxies. Taking into account a selection bias of the Oxygen-excess method, we showed that strong <span class="hlt">AGNs</span> are located in active star-forming galaxies, and that rapidly growing super-massive black holes are located in rapidly growing galaxies, which clearly shows the coevolution of super-massive black holes and their host galaxies. This is a surprising phenomenon, given that the growths of black holes and host galaxies occur on their respective physical scales which are very different. Interestingly, the <span class="hlt">AGN</span> power does not strongly correlate with the host-galaxy mass. It seems that the mass works as a ``switch'' for activating <span class="hlt">AGNs</span>. The absence of <span class="hlt">AGNs</span> in low-mass galaxies might be due to the absence of super-massive black holes there, but a dedicated observation of the nuclear region of nearby low-mass galaxies would be necessary to obtain a deeper insight into it.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MNRAS.464.2139A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MNRAS.464.2139A"><span>Probing the active galactic nucleus unified <span class="hlt">model</span> torus properties in Seyfert galaxies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Audibert, Anelise; Riffel, Rogério; Sales, Dinalva A.; Pastoriza, Miriani G.; Ruschel-Dutra, Daniel</p> <p>2017-01-01</p> <p>We studied the physical parameters of a sample comprising of all Spitzer/Infrared Spectrograph public spectra of Seyfert galaxies in the mid-infrared (5.2-38 μm range) under the active galactic nucleus (<span class="hlt">AGN</span>) unified <span class="hlt">model</span>. We compare the observed spectra with ˜106 CLUMPY <span class="hlt">model</span> spectral energy distributions, which consider a torus composed of dusty clouds. We find a slight difference in the distribution of line-of-sight inclination angle, i, requiring larger angles for Seyfert 2 (Sy 2) and a broader distribution for Seyfert 1 (Sy 1). We found small differences in the torus angular width, σ, indicating that Sy 1 may host a slightly narrower torus than Sy 2. The torus thickness, together with the bolometric luminosities derived, suggests a very compact torus up to ˜6 pc from the central <span class="hlt">AGN</span>. The number of clouds along the equatorial plane, N, as well the index of the radial profile, q, is nearly the same for both types. These results imply that the torus cloud distribution is nearly the same for type 1 and type 2 objects. The torus mass is almost the same for both types of activity, with values in the range of Mtor ˜ 104-107 M⊙. The main difference appears to be related to the clouds' intrinsic properties: type 2 sources present higher optical depths τV. The results presented here reinforce the suggestion that the classification of a galaxy may also depend on the intrinsic properties of the torus clouds rather than simply on their inclination. This is in contradiction with the simple geometric idea of the <span class="hlt">unification</span> <span class="hlt">model</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApJ...827...58S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApJ...827...58S"><span>Obscured <span class="hlt">AGNs</span> in Bulgeless Hosts discovered by WISE: The Case Study of SDSS J1224+5555</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Satyapal, S.; Secrest, N. J.; Rothberg, B.; O'Connor, J. A.; Ellison, S. L.; Hickox, R. C.; Constantin, A.; Gliozzi, M.; Rosenberg, J. L.</p> <p>2016-08-01</p> <p>There is mounting evidence that supermassive black holes (SMBHs) form and grow in bulgeless galaxies. However, a robust determination of the fraction of active galactic nuclei (<span class="hlt">AGNs</span>) in bulgeless galaxies, an important constraint to <span class="hlt">models</span> of SMBH seed formation and merger-free <span class="hlt">models</span> of <span class="hlt">AGN</span> fueling, is unknown, since optical studies have been shown to be incomplete for <span class="hlt">AGNs</span> in low-mass galaxies. In a recent study using the Wide-field Infrared Survey Explorer, we discovered hundreds of bulgeless galaxies that display mid-infrared signatures of extremely hot dust suggestive of powerful accreting massive black holes, despite having no signatures of black hole activity at optical wavelengths. Here we report X-ray follow-up observations of J122434.66+555522.3, a nearby (z = 0.052) isolated bulgeless galaxy that contains an unresolved X-ray source detected at the 3σ level by XMM-Newton with an observed luminosity uncorrected for intrinsic absorption of {L}2-10{keV}=(1.1+/- 0.4)× {10}40 erg s-1. Ground-based near-infrared spectroscopy with the Large Binocular Telescope and multiwavelength observations from ultraviolet to millimeter wavelengths together suggest that J1224+5555 harbors a highly absorbed <span class="hlt">AGN</span> with an intrinsic absorption of {N}{{H}}\\gt {10}24 cm-2. The hard X-ray luminosity of the putative <span class="hlt">AGN</span> corrected for absorption is {L}2-10{keV}˜ 3× {10}42 erg s-1, which, depending on the bolometric correction factor, corresponds to a bolometric luminosity of the <span class="hlt">AGN</span> of {L}{bol}.˜ 6× {10}43-3 × 1044 {erg} {{{s}}}-1 and a lower mass limit for the black hole of {M}{BH}≃ 2× {10}6 {M}⊙ , based on the Eddington limit. While enhanced X-ray emission and hot dust can be produced by star formation in extremely low metallicity environments typical in dwarf galaxies, J1224+5555 has a stellar mass of ˜ 2.0× {10}10 {M}⊙ and an above solar metallicity (12 + {logO}/{{H}} = 9.11), typical of our WISE-selected bulgeless galaxy sample. While collectively these</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016cosp...41E.774G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016cosp...41E.774G"><span>Review of Space VLBI RadioAstron studies of <span class="hlt">AGN</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gurvits, Leonid; Kovalev, Yuri</p> <p>2016-07-01</p> <p>Space VLBI offers an unrivalled resolution in studies of the <span class="hlt">AGN</span> phenomena. Since 2011, the Russia-led SVLBI mission RadioAstron conducts observations at 92, 18, 6 and 1.3 cm with baselines an order of magnitude longer than the Earth diameter, therefore offering an order of magnitude "sharper" view at the brightest radio sources than achieved with Earth-based VLBI systems. In our presentation we will review the current status of the RadioAstron's scientific programme. Over the first 4.5 years of the in-orbit operations, the mission achieved successful VLBI detections of extragalactic continuum radio sources at all four observing bands. To date, detections on SVLBI baselines have been obtained for more than 150 <span class="hlt">AGN</span>'s at projected baselines up to 350 000 km (about 28 Earth diameters, ED). The highest resolution achieved is 14 microarcscends from 1.3 cm observations. RadioAstron is an international project; it conducts observations with up to 30 Earth-based radio telescopes located on different continents. We will review results of total intensity and polarisation imaging with extreme angular resolution of blazars and nearby active galaxies. We will also discuss typical and maximum brightness temperatures of blazar cores from the <span class="hlt">AGN</span> Survey obtained with RadioAstron. Physical implications for the <span class="hlt">AGN</span> jets formation, magnetic field and emission mechanism will be discussed on the basis of the results obtained to date.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=wilcox&id=EJ750559','ERIC'); return false;" href="http://eric.ed.gov/?q=wilcox&id=EJ750559"><span>Converting the Audience: A Conversation with <span class="hlt">Agnes</span> Wilcox</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Becker, Becky</p> <p>2006-01-01</p> <p>This article presents a conversation with <span class="hlt">Agnes</span> Wilcox, Executive Director of Prison Performing Arts in St. Louis, Missouri, about Prison Performing Arts. Although the average person might balk at the notion of interacting with prison inmates, finding it intimidating, worrisome, or self-sacrificial, for Wilcox, Prison Performing Arts is a…</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AAS...21915423T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AAS...21915423T"><span>X-Ray Selected <span class="hlt">AGN</span> in A Merging Cluster</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Taylor, Joanna M.; Norman, D.; Soechting, I.; Coldwell, G.</p> <p>2012-01-01</p> <p>We investigate the X-ray <span class="hlt">AGN</span> population and evolution in the merging galaxy cluster DLSCL J0522.2-4820 discovered via weak gravitational lensing shear from the Deep Lens Survey (DLS). Since weak lensing shear is dependent only on mass, it does not introduce the biases that typical cluster selection methods do. This cluster is of particular interest due to both its extended multiple X-ray emission peaks and the large number of X-ray point sources identified in the field. We measured the redshifts of X-ray <span class="hlt">AGN</span> as well as cluster galaxies in order to investigate the 3-dimensional distribution and possible clustering of <span class="hlt">AGN</span> in galaxy clusters. Of the 125 objects in our sample, 54 are galaxies in the cluster; the cluster redshift is determined to be z=0.2997±0.0096. This agrees well with a previous value of z=0.296±0.001. We identified several broad line <span class="hlt">AGN</span> at high redshift including a quasar pair at redshift z=1.8. Currently, we have found no X-ray point sources to be within the cluster. This project was supported by the NOAO/KPNO Research Experiences for Undergraduates (REU) Program which is funded by the National Science Foundation Research Experiences for Undergraduates Program and the Department of Defense ASSURE program through Scientific Program Order No. 13 (AST-0754223) of the Cooperative Agreement No. AST-0132798 between the Association of Universities for Research in Astronomy (AURA) and the NSF.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013HEAD...1310816B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013HEAD...1310816B"><span>First Results from the NuSTAR <span class="hlt">AGN</span> Physics Program</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brenneman, Laura; Fuerst, F.; Matt, G.; Walton, D.; Madejski, G. M.; Marinucci, A.; Elvis, M.; Risaliti, G.; Harrison, F.; Stern, D.; Boggs, S.; Christensen, F.; Craig, W. W.; Zhang, W.; NuSTAR Team</p> <p>2013-04-01</p> <p>The Nuclear Spectroscopic Telescope Array (NuSTAR, launched June 2012) is revolutionizing our knowledge of the physics at work in active galactic nuclei (<span class="hlt">AGN</span>). With its high collecting area, focusing optics and low background from 3-79 keV, NASA's newest X-ray observatory is providing an unprecedented look at the spectral and timing properties of <span class="hlt">AGN</span> in this energy range, which have been notoriously difficult to access. NuSTAR has observed several <span class="hlt">AGN</span> to date simultaneously with XMM-Newton, Suzaku and/or Swift for the purposes of understanding their coronal properties (e.g., plasma temperature, optical depth) and measuring the spins of their supermassive black holes. We present the first results from these observing campaigns, highlighting the spectral and timing analysis of the bright, nearby <span class="hlt">AGN</span> IC 4329A, NGC 4151, NGC 1365 and MCG--6-30-15. These are the highest signal-to-noise datasets ever obtained across the 0.2-79 keV energy band for these three sources, allowing us to cleanly deconvolve the X-ray continuum, absorption and reflection components in each galaxy for the first time via time-averaged and time-resolved spectroscopy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015MNRAS.450.1538W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015MNRAS.450.1538W"><span>Radio-<span class="hlt">AGN</span> feedback: when the little ones were monsters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Williams, W. L.; Röttgering, H. J. A.</p> <p>2015-06-01</p> <p>We present a study of the evolution of the fraction of radio-loud active galactic nuclei (<span class="hlt">AGN</span>) as a function of their host stellar mass. We make use of two samples of radio galaxies: one in the local Universe, 0.01 < z ≤ 0.3, using a combined SDSS-NVSS (Sloan Digital Sky Survey NRAO Very Large Array Sky Survey) sample and the other at higher redshifts, 0.5 < z ≤ 2, constructed from the VLA-COSMOS_DEEP Radio Survey at 1.4 GHz and a Ks-selected catalogue of the COSMOS/UltraVISTA field. We observe an increase of more than an order of magnitude in the fraction of lower mass galaxies (M* < 1010.75 M⊙) which host radio-loud <span class="hlt">AGN</span> with radio powers P1.4 GHz > 1024 W Hz-1 at z ˜ 1-2 while the radio-loud fraction for higher mass galaxies (M* > 1011.25 M⊙) remains the same. We argue that this increase is driven largely by the increase in cold or radiative mode accretion with increasing cold gas supply at earlier epochs. The increasing population of low-mass radio-loud <span class="hlt">AGN</span> can thus explain the upturn in the radio luminosity function at high redshift which is important for understanding the impact of <span class="hlt">AGN</span> feedback in galaxy evolution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017hsa9.conf..169H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017hsa9.conf..169H"><span>Unveiling the physics of <span class="hlt">AGN</span> through X-ray variability</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hernández-García, L.; González-Martín, O.; Masegosa, J.; Márquez, I.</p> <p>2017-03-01</p> <p>Although variability is a general property characterizing active galactic nuclei (<span class="hlt">AGN</span>), it is not well established whether the changes occur in the same way in every nuclei. The main purpose of this work is to study the X-ray variability pattern(s) in <span class="hlt">AGN</span> selected at optical wavelengths in a large sample, including low ionization nuclear emission line regions (LINERs) and type 1.8, 1.9, and 2 Seyferts, using the public archives in Chandra and/or XMM–Newton. Spectra of the same source gathered at different epochs were simultaneously fitted to study long term variations; the variability patterns were studied allowing different parameters to vary during the spectral fit. Whenever possible, short term variations from the analysis of the light curves and long term UV flux variability were studied. Variations at X-rays in timescales of months/years are very common in all <span class="hlt">AGN</span> families but short term variations are only found in type 1.8 and 1.9 Seyferts. The main driver of the long term X-ray variations seems to be related to changes in the nuclear power. Other variability patterns cannot be discarded in a few cases. We discuss the geometry and physics of <span class="hlt">AGN</span> through the X-ray variability analysis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AAS...22710405P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AAS...22710405P"><span>Understanding <span class="hlt">AGNs</span> in the Local Universe through Optical Reverberation Mapping</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pei, Liuyi</p> <p>2016-01-01</p> <p>I present the results of observational projects aimed at measuring the mass of the black hole at the center of active galactic nuclei (<span class="hlt">AGNs</span>) and understanding the structure and kinematics of the broad-line emitting gas within the black hole's sphere of influence.The first project aims to measure the black hole mass in the Kepler-field <span class="hlt">AGN</span> KA1858. We obtained simultaneous spectroscopic data from the Lick Observatory 3-m telescope using the Kast Double Spectrograph and photometry data from five ground-based telescopes, and used reverberation mapping (RM) techniques to measure the emission-line light curves' lags relative to continuum variations. We obtained lags for H-beta, H-gamma, H-delta, and He II, and obtained the first black hole mass measurement for this object. Our results will serve as a reference point for future studies on relations between black hole mass and continuum variability characteristics using Kepler <span class="hlt">AGN</span> light curves.The second project, in collaboration with the <span class="hlt">AGN</span> STORM team, aims to understand the structure and dynamics of the broad line region (BLR) in NGC 5548 in both UV and optical wavelengths. To supplement 6 months of HST UV observations, we obtained simultaneous optical spectroscopic data from six ground-based observatories. We obtained emission-line lags for the optical H-beta and He II lines as well as velocity-resolved lag measurements for H-beta. We also compared the velocity-resolved lags for H-beta to the UV emission lines C IV and Ly-alpha and found similar lag profiles for all three lines.Finally, I will discuss my contributions to two other collaborations in <span class="hlt">AGN</span> RM. A key component in RM is monitoring continuum variability, which is often done through ground-based photometry. I will present a pipeline that performs aperture photometry on any number of images of an <span class="hlt">AGN</span> with WCS coordinates and immediately produces relative light curves. This pipeline enables quick looks of <span class="hlt">AGN</span> variability in real time and has been used in the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AJ....151...81W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AJ....151...81W"><span>A Direct Linkage between <span class="hlt">AGN</span> Outflows in the Narrow-line Regions and the X-Ray Emission from the Accretion Disks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, J.; Xu, D. W.; Wei, J. Y.</p> <p>2016-03-01</p> <p>The origin of outflow in the narrow-line region (NLR) of the active galactic nucleus (<span class="hlt">AGN</span>) is studied in this paper by focusing on the relationship between the [O iii]λ5007 line profile and the hard-X-ray (in a bandpass of 2-10 keV) emission from the central super-massive black hole (SMBH) in type-I <span class="hlt">AGNs</span>. A sample of 47 local X-ray selected type-I <span class="hlt">AGNs</span> at z\\lt 0.2 is extracted from the 2XMMi/SDSS-DR7 catalog, which was originally cross-matched by Pineau et al. The X-ray luminosities in an energy band from 2 to 10 keV of these luminous <span class="hlt">AGNs</span> range from 1042 to {10}44 {erg} {{{s}}}-1. A joint spectral analysis is performed on their optical and X-ray spectra, in which the [O iii] line profile is <span class="hlt">modeled</span> by a sum of several Gaussian functions to quantify its deviation from a pure Gaussian function. The statistics allow us to identify a moderate correlation with a significance level of 2.78σ: luminous <span class="hlt">AGNs</span> with stronger [O iii] blue asymmetry tend to have steeper hard-X-ray spectra. By identifying the role of L/{L}{Edd} on the correlation at a 2-3σ significance level in both direct and indirect ways, we argue that the photon index versus the asymmetry correlation provides evidence that the AGN’s outflow commonly observed in its NLR is related to the accretion process occurring around the central SMBH, which favors the wind/radiation <span class="hlt">model</span> as the origin of the outflow in luminous <span class="hlt">AGNs</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016A%26A...594A..44H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016A%26A...594A..44H"><span>Large-scale outflows in luminous QSOs revisited. The impact of beam smearing on <span class="hlt">AGN</span> feedback efficiencies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Husemann, B.; Scharwächter, J.; Bennert, V. N.; Mainieri, V.; Woo, J.-H.; Kakkad, D.</p> <p>2016-10-01</p> <p>Context. Feedback from active galactic nuclei (<span class="hlt">AGN</span>) is thought to play an important role in quenching star formation in galaxies. However, the efficiency with which <span class="hlt">AGN</span> dissipate their radiative energy into the ambient medium remains strongly debated. Aims: Enormous observational efforts have been made to constrain the energetics of <span class="hlt">AGN</span> feedback by mapping the kinematics of the ionized gas on kpc scale. We study how the observed kinematics and inferred energetics are affected by beam smearing of a bright unresolved narrow-line region (NLR) due to seeing. Methods: We re-analyse optical integral-field spectroscopy of a sample of twelve luminous unobscured quasi-stellar objects (QSOs) (0.4 <z< 0.7) previously presented in the literature. The point-spread function (PSF) for the observations is directly obtained from the light distribution of the broad Hβ line component. Therefore, we are able to compare the ionized gas kinematics and derived energetics of the total, truly spatially extended, and unresolved [O iii] emission. Results: We find that the spatially resolved [O iii] line width on kpc scales is significantly narrower than the one before PSF deblending. The extended NLRs (ENLRs) appear intrinsically offset from the QSO position or more elongated which can be interpreted in favour of a conical outflow on large scales while a spherical geometry cannot be ruled out for the unresolved NLR. We find that the kinetic power at 5 kpc distance based on a spherical <span class="hlt">model</span> is reduced by two orders of magnitude for a conical outflow and one order of magnitude for the unresolved NLR after PSF deblending. This reduced kinetic power corresponds to only 0.01-0.1 per cent of the bolometric <span class="hlt">AGN</span> luminosity. This is smaller than the 5-10% feedback efficiency required by some cosmological simulations to reproduce the massive galaxy population. The injected momentum fluxes are close or below the simple radiation-pressure limit Lbol/c for the conical outflow <span class="hlt">model</span> for the NLR and ENLR</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005A%26A...444..431S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005A%26A...444..431S"><span>INTEGRAL observations of six <span class="hlt">AGN</span> in the Galactic Plane</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Soldi, S.; Beckmann, V.; Bassani, L.; Courvoisier, T. J.-L.; Landi, R.; Malizia, A.; Dean, A. J.; de Rosa, A.; Fabian, A. C.; Walter, R.</p> <p>2005-12-01</p> <p>We present results on approximately one year of INTEGRAL observations of six <span class="hlt">AGN</span> detected during the regular scans of the Galactic Plane. The sample is composed by five Seyfert 2 objects (MCG 05 23 16, NGC 4945, the Circinus galaxy, NGC 6300, ESO 103 G35) and the radio galaxy Centaurus A. The continuum emission of each of these sources is well represented by a highly absorbed (N_H>1022 cm-2) power law, with average spectral index Γ = 1.9 ± 0.3. A high energy exponential cut-off at Ec ˜ 50 ~keV is required to fit the spectrum of the Circinus galaxy, whereas a lower limit of 130 keV has been found for NGC 4945 and no cut-off has been detected for NGC 6300 in the energy range covered by these INTEGRAL data. The flux of Centaurus A was found to vary by a factor of ~2 in 10 months, showing a spectral change between the high and low state, which can be <span class="hlt">modelled</span> equally well by a change in the absorption (NH from 17 to 33 × 1022 cm-2) or by the presence of a cut-off at ⪆120 keV in the low state spectrum. A comparison with recently reprocessed BeppoSAX/PDS data shows a general agreement with INTEGRAL results. The high energy cut-off in the hard X-ray spectra appears to be a common but not universal characteristic of Seyfert 2 and to span a wide range of energies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AAS...22934735W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AAS...22934735W"><span>Incidence of WISE-Selected Obscured <span class="hlt">AGNs</span> in Major Mergers and Interactions from the SDSS</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Weston, Madalyn; McIntosh, Daniel H.; Brodwin, Mark; Mann, Justin; Cooper, Andrew; McConnell, Adam; Nielson, Jennifer L.</p> <p>2017-01-01</p> <p>We use the Wide-field Infrared Survey Explorer (WISE) and the Sloan Digital Sky Survey (SDSS) to confirm a connection between dust-obscured active galactic nuclei (<span class="hlt">AGNs</span>) and galaxy merging. Using a new, volume-limited (z≤0.08) catalog of visually-selected major mergers and galaxy-galaxy interactions from the SDSS, with stellar masses above 2×10^10 M⊙, we find that major mergers (interactions) are 5--17 (3--5) times more likely to have red [3.4]-[4.6] colors associated with dust-obscured or `dusty' <span class="hlt">AGNs</span>, compared to non-merging galaxies with similar masses. Using published fiber spectral diagnostics, we map the [3.4]-[4.6] versus [4.6]-[12] colors of different emission-line galaxies and find one-quarter of Seyferts have colors indicative of a dusty <span class="hlt">AGN</span>. We find that <span class="hlt">AGNs</span> are five times more likely to be obscured when hosted by a merging galaxy, half of <span class="hlt">AGNs</span> hosted by a merger are dusty, and we find no enhanced frequency of optical <span class="hlt">AGNs</span> in merging over non-merging galaxies. We conclude that undetected <span class="hlt">AGNs</span> missed at shorter wavelengths are at the heart of the ongoing <span class="hlt">AGN</span>-merger connection debate. The vast majority of mergers hosting dusty <span class="hlt">AGNs</span> are star-forming and located at the centers of Mhalo<10^13 M⊙ groups. Assuming plausibly short duration dusty-<span class="hlt">AGN</span> phases, we speculate that a large fraction of gas-rich mergers experience a brief obscured <span class="hlt">AGN</span> phase, in agreement with the strong connectio