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Sample records for qso host galaxy

  1. The Luminosity Function of QSO Host Galaxies

    NASA Technical Reports Server (NTRS)

    Hamilton, Timothy S.; Casertano, Stefano; Turnshek, David A.; White, Nicholas E. (Technical Monitor)

    2002-01-01

    We present some results from our HST archival image study of 71 QSO host galaxies. The objects are selected to have z less than or equal to 0.46 and total absolute magnitude M(sub v) less than or equal to -23 in our adopted cosmology (H(sub 0) = 50 kilometers per second Mpc(sup-1), q(sub 0) = 0.5, lambda = 0)). The aim of this initial study is to investigate the composition of the sample with respect to host morphology and radio loudness, as well as derive the QSO host galaxy luminosity function. We have analyzed available WFPC2 images in R or I band (U in one case), using a uniform set of procedures. The host galaxies span a narrow range of luminosities and are exceptionally bright, much more so than normal galaxies, usually L greater than L*(sub v). The QSOs are almost equally divided among three subclasses: radio-loud QSOs with elliptical hosts, radio-quiet QSOs with elliptical hosts, and radio-quiet QSOs with spiral hosts. Radio-loud QSOs with spiral hosts are extremely rare. Using a weighting procedure, we derive the combined luminosity function of QSO host galaxies. We find that the luminosity function of QSO hosts differs in shape from that of normal galaxies but that they coincide at the highest luminosities. The ratio of the number of quasar hosts to the number of normal galaxies at a luminosity L*(sub v) is R = (Lv/11.48L*(sub v))(sup 2.46), where L*(sub v) corresponds to M*(sub v)= -22.35, and a QSO is defined to be an object with total nuclear plus host light M(sub v) less than or equal to -23. This ratio can be interpreted as the probability that a galaxy with luminosity L(sub V) will host a QSO at redshift z approximately equal to 0.26.

  2. Study of a homogeneous QSO sample: relations between the QSO and its host galaxy

    NASA Astrophysics Data System (ADS)

    Letawe, Y.; Letawe, G.; Magain, P.

    2010-04-01

    We analyse a sample of 69 quasi-stellar objects (QSOs) which have been randomly selected in a complete sample of 104 QSOs (R <= 18,0.142 < z < 0.198,δ < 10°). 60 have been observed with the NTT/SUSI2 at La Silla, through two filters in the optical band (WB 655 and V 812), and the remaining nine are taken from archive data bases. The filter V 812 contains the redshifted Hβ and forbidden [OIII] emission lines, while WB 655 covers a spectral region devoid of emission lines, thus measuring the QSO and stellar continua. The contributions of the QSO and the host are separated thanks to the MCS deconvolution algorithm, allowing a morphological classification of the host, and the computation of several parameters such as the host and nucleus absolute V magnitude, distance between the luminosity centre of the host and the QSO and colour of the host and nucleus. We define a new asymmetry coefficient, independent of any galaxy models and well suited for QSO host studies. The main results from this study are (i) 25 per cent of the total number of QSO hosts are spirals, 51 per cent are ellipticals and 60 per cent show signs of interaction, (ii) highly asymmetric systems tend to have a higher gas ionization level and (iii) elliptical hosts contain a substantial amount of ionized gas and some show off-nuclear activity. These results agree with hierarchical models merger driven evolution. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile, under programme IDs 77.B-0229 and 78.B-0081. E-mail: gletawe@ulg.ac.be

  3. Morphology of QSO host galaxies --- a look at the SED

    NASA Astrophysics Data System (ADS)

    Andrei, A.; Coelho, B.; Anton, S.

    2015-08-01

    The Gaia Initial QSO Catalogue presents several characteristics of its 1,248,372 listed objects, among which the optical morphological type. From this a program studies the host galaxies of QSOs present in the SDSS up to its 8th release, based on retrieving a data bank of images in the five ugriz colors for the 105,783 objects spectroscopically found as QSOs. The first scope of this program is to study QSOs for which the isophotes of the host galaxy are not pronounced, so that the centroid determination is not affected for those fundamental grid-points of the Gaia Celestial Reference Frame. Since the target images come from relatively short exposures, we developed an approach to access disturbances of the target PSF relatively to the nearby stars. Here we focus on the first results for absolute magnitude of QSOs combining the SDSS colors and the SED library from Gaia.

  4. The MUSE QSO Blind Survey: A Census of Absorber Host Galaxies

    NASA Astrophysics Data System (ADS)

    Straka, Lorrie A.

    2017-03-01

    Understanding the distribution of gas in galaxies and its interaction with the IGM is crucial to complete the picture of galaxy evolution. At all redshifts, absorption features seen in QSO spectra serve as a unique probe of the gaseous content of foreground galaxies and the IGM, extending out to 200 kpc. Studies show that star formation history is intimately related to the co-evolution of galaxies and the IGM. In order to study the environments traced by absorption systems and the role of inflows and outflows, it is critical to measure the emission properties of host galaxies and their halos. We overcome the challenge of detecting absorption host galaxies with the MUSE integral field spectrograph on VLT. MUSE's large field of view and sensitivity to emission lines has allowed a never-before seen match between the number density of absorbers along QSO sightlines and the number density of emission line galaxies within 200 kpc of the QSO. These galaxies represent a sample for which previously elusive connections can be made between mass, metallicity, SFR, and absorption.

  5. Adaptive optics imaging of QSO host galaxies with Hokupa'a on the Gemini North telescope

    NASA Astrophysics Data System (ADS)

    Guyon, O.; Sanders, D. B.; Stockton, A.; Baudoz, P.; Potter, D.

    2001-05-01

    We report the initial results of a new near-infrared imaging survey of quasar hosts using the University of Hawaii Hokupa'a Adaptive Optics system on the 8.2m Gemini-North telescope. J,H,K' images of a complete subsample ( 25) of nearby (z <0.3), "bona-fide" optically selected (MB < -23; Ho = 50, qo=0; Schmidt & Green 1983) QSOs are being taken in order to obtain accurate host galaxy magnitudes and colors and to determine two-dimensional structure. In the initial phase of our observations we found that PSF subtraction residuals were severely limiting our ability to characterize the host galaxy. However we were able to obtain a significant increase in stability of the PSF by turning off the Cassegrain rotator during observations (see Roth et al. contribution at this meeting). Our sample of Palomar-Green Bright QSOs includes both radio quiet and radio loud objects plus objects spanning the full range of observed "infrared excess" continuum emission. One of the most surprising results has been the detection of modest scale (3-5" 5 kpc diameter) "bars" and/or circumnuclear "disks" that were not evident in previous one-dimensional profile analyses. These structures may be related to the reservoir of fuel needed to power the QSO and may provide important clues concerning the origin and evolution of QSO hosts.

  6. A Monster At Any Other Epoch: Are Intermediate Redshift ULIRGs the Progenitors of QSO Host Galaxies?

    NASA Astrophysics Data System (ADS)

    Rothberg, Barry; Fischer, Jackie; Rodrigues, Myriam; Pirzkal, Nor

    2015-08-01

    There is a clear progression from merger-induced SF to QSO activity via Ultraluminous Infrared Galaxies (ULIRGs). While not all mergers are ULIRGs, multi-wavelength imaging confirms that all local ULIRGs are mergers. At 0.4 < z < 1.0, the star-formation rates, gas fractions, and masses are believed to be significantly higher than in the local universe (i.e. due to "Downsizing"). ULIRGs begin to dominate the SF activity in the Universe at z˜0.7, and at z>1 are responsible for ˜ 70% of the co-moving IR density. At these earlier epochs ULIRGs contained more gas, formed stars faster, and their number density was much higher. At z>1 there are conflicting conclusions about ULIRGs. Many studies conclude they are massive star-forming galaxies, not major mergers nor AGN. Nearly all studies of ULIRGs at z > 0.4 have selected these systems via scaling observed 24μm or 170μm Spitzer fluxes to integrated 8-1000μm fluxes and inferring masses from scaling photometric fluxes or millimeter observations of CO gas emission. These methods often rely heavily on uncertain assumptions (e.g. gas conversions, SED fitting and templates). Instead, we have assembled a representative sample of "classically" selected ULIRGs (60 and 100μm IRAS fluxes and 12 and 25μm WISE fluxes) for 0.4 < z < 1.0 and obtained optical and near-IR imaging and spectroscopy from Hubble Space Telescope, Keck, and the Large Binocular Telescope. We use the same techniques for measuring the dynamical and BH masses of ULIRGs in the local Universe to measure these parameters in more distant systems. Unlike other methods, we directly measure the mass at an epoch when galaxy formation and evolution appears to have changed dramatically from what we see today and compare these intermediate redshift ULIRGs with their counterparts in the local Universe. Our restframe optical and UV spectroscopy also allow us to directly probe gas-metallicities, outflows, and measure the properties of their stellar populations. Our

  7. PROVIDING STRINGENT STAR FORMATION RATE LIMITS OF z ∼ 2 QSO HOST GALAXIES AT HIGH ANGULAR RESOLUTION

    SciTech Connect

    Vayner, Andrey; Wright, Shelley A.; Do, Tuan; Larkin, James E.; Armus, Lee; Gallagher, S. C.

    2016-04-10

    We present integral field spectrograph (IFS) with laser guide star adaptive optics (LGS-AO) observations of z ∼ 2 quasi-stellar objects (QSOs) designed to resolve extended nebular line emission from the host galaxy. Our data was obtained with W. M. Keck and Gemini North Observatories, using OSIRIS and NIFS coupled with the LGS-AO systems, respectively. We have conducted a pilot survey of five QSOs, three observed with NIFS+AO and two observed with OSIRIS+AO at an average redshift of z = 2.2. We demonstrate that the combination of AO and IFSs provides the necessary spatial and spectral resolutions required to separate QSO emission from its host. We present our technique for generating a point-spread function (PSF) from the broad-line region of the QSO and performing PSF subtraction of the QSO emission to detect the host galaxy emission at a separation of ∼0.″2 (∼1.4 kpc). We detect Hα narrow-line emission for two sources, SDSS J1029+6510 (z{sub Hα} = 2.182) and SDSS J0925+0655 (z{sub Hα} = 2.197), that have evidence for both star formation and extended narrow-line emission. Assuming that the majority of narrow-line Hα emission is from star formation, we infer a star formation rate (SFR) for SDSS J1029+6510 of 78.4 M{sub ⊙} yr{sup −1} originating from a compact region that is kinematically offset by 290–350 km s{sup −1}. For SDSS J0925+0655 we infer a SFR of 29 M{sub ⊙} yr{sup −1} distributed over three clumps that are spatially offset by ∼7 kpc. The null detections on three of the QSOs are used to infer surface brightness limits and we find that at 1.4 kpc from the QSO the un-reddened star formation limit is ≲0.3 M{sub ⊙} yr{sup −1} kpc{sup −2}. If we assume typical extinction values for z = 2 type-1 QSOs, the dereddened SFR for our null detections would be ≲0.6 M{sub ⊙} yr{sup −1} kpc{sup −2}. These IFS observations indicate that while the central black hole is accreting mass at 10%–40% of the Eddington rate, if

  8. High-z QSO Absorption Systems: Metal-Poor Cold Flows and Mg II Absorber Host Galaxies

    NASA Astrophysics Data System (ADS)

    Cooper, Thomas; Simcoe, R. A.; Cooksey, K.; O'Meara, J.

    2014-01-01

    Cosmological simulations have suggested a new model for gas accretion in young galaxies, in which baryons flow into the star-forming disk along filamentary streams without shock heating at the dark matter halo virial radius. Observationally, these cold flows manifest as Lyman Limit Systems with low heavy element abundances. To search for cold flows in the early Universe, we have obtained echellette-resolution spectra of an HI-selected sample of LLS at z>3.5 from the Sloan Digital Sky Survey. The sightlines were selected to exhibit no heavy element absorption at the resolution afforded by SDSS, and the higher resolution data provides metallicity measurements precise enough to determine if they exhibit cold flow accretion characteristics. In a parallel program, we use the Magellan Telescopes and HST/WFC-3 to investigate the connection between Mg II absorbers and proximate galaxies at 3, extending fruitful studies of the circumgalactic medium to larger redshift.

  9. QSO clustering - II. The correlation function of IRAS seyfert galaxies.

    NASA Astrophysics Data System (ADS)

    Georgantopoulos, I.; Shanks, T.

    1994-12-01

    We investigate the clustering properties of 192 Seyfert galaxies from the IRAS all-sky survey. Using the spatial correlation function, we detect evidence of Seyfert clustering at the 2σ confidence level at < 10 h^-1^ Mpc separations, and at the 3{SIGMA} level at < 20 h^-1^ Mpc separations. Comparison of the QSO correlation function amplitude at high redshifts, z = 1.4, with that of Seyferts below 10 h^-1^ comoving Mpc leads us to reject the stable model of AGN clustering evolution at the 4σ level, whereas a comoving model where QSOs randomly sample the galaxy distribution is more consistent. The main uncertainty here now lies in the statistical error on the amplitude of the clustering in the faint QSO surveys at z = 1.4. The Seyfert-QDOT cross-correlation function is measured to be approximately a factor of 2 higher than the QDOT galaxy autocorrelation function, suggesting an enhanced environment for Seyferts with respect to IRAS galaxies, but it is not clear whether this is also the case with respect to optical galaxies. We conclude that the comoving model is probably favoured overall, at least on the r < 10 h^-1^ Mpc scales investigated here, but it is not yet possible to rule out intermediate models: for example, an enhanced-environment, stable model with ξ(r)=(r/3)^-1.8^ at z = 1.4, which is statistically consistent with the faint QSO data.

  10. Probing the Circumgalactic Medium of Submillimeter Galaxies with QSO Absorption Line Spectroscopy

    NASA Astrophysics Data System (ADS)

    Fu, Hai; Hennawi, Joseph F.; Prochaska, Jason X.; Stockton, Alan N.; Mutel, Robert Lucien; Casey, Caitlin; Cooray, Asantha R.; Keres, Dusan

    2017-01-01

    We present first results from an ongoing survey to characterize the circumgalactic medium (CGM) of the massive high-redshift galaxieds detected as submillimeter galaxies (SMGs). By cross-matching far-infrared-selected galaxies from Herschel with spectroscopically confirmed quasars, we constructed a sample of 163 SMG-QSO pairs with separations less than 36". We observed 62 SMG-QSO pairs with the Very Large Array (VLA) and the Atacama Large Millimeter Array (ALMA). These observations obtained sub-arcsecond positions of 31 SMGs and identified seven previously-thought SMG-QSO pairs as submillimeter-luminous QSOs. We are currently conducting a redshift survey of the VLA/ALMA-confirmed SMGs and acquiring high S/N UV-optical specrtoscopy of the background QSOs. For the small sample of three VLA-confirmed SMG-QSO pairs that we have the complete data set, absorption line spectra of the background QSOs allow us to analyze the CGM of SMGs for the first time, providing insight into the fuel-supply ultimately powering their tremendous starbursts. Our observations reveal strong HI Ly-alpha absorption (rest-frame equivalent widths about 2-3 A) around all three SMGs; however, none exhibit compelling evidence for strong neutral absorbers (NHI > 1017.2 cm-2) or metal absorption, allowing us to place an 1-sigma upper limit on the covering factor of optically thick HI gas around SMGs of fC < 36.9%. This is significantly lower than the covering factor around the co-eval population of luminous QSOs. Theoretical models predict that the structure of the CGM is entirely determined by dark matter halo mass. Given that that SMGs are believed to inhabit massive dark matter halos comparable to those hosting quasars, this difference in covering factor is unexpected. Therefore, our results tentatively indicate that SMGs may not have substantial cool gas reservoirs in their halos and that they may inhabit much less massive halos than previously thought.

  11. The Host Galaxies of Nearby, Optically Luminous, AGN

    NASA Astrophysics Data System (ADS)

    Petric, Andreea

    2016-01-01

    Coevolution of galaxies and their central black holes (BH) has been the central theme of much of recent extragalactic astronomical research. Observations of the dynamics of stars and gas in the nuclear regions of nearby galaxies suggest that the majority of spheroidal galaxies in the local Universe contain massive BHs and that the masses of those central BH correlate with the velocity dispersions of the stars in the spheroid and the bulge luminosity. Cold ISM is the basic fuel for star-formation and BH growth so its study is essential to understanding how galaxies evolve.I will present high sensitivity observations taken with the Herschel Space Observatory to measure the cold dust content in a sample of 85 nearby (z <= 0.5) QSOs chosen from the optically luminous broad-line PG QSOs sample (QSO1s) and in a complementary sample of 85 narrow-line QSOs (QSO2s) chosen to match the redshift and optical luminosity distribution of the broad-line targets. The FIR data are combined with NIR and MIR measurements from the Two Micron All Sky Survey and the Wide-Field Infrared Survey Explorer to determine their IR spectral energy distributions which we use to assess and compare the aggregate dust properties of QSO1s and QSO2s. I will also present NIR spectroscopy obtained with Gemini's Near-Infrared Spectrograph of a sub-sample of QSO2s and QSO1s which I use to compare the ratio of cold to warm H2 gas that emits in the NIR in the hosts of QSO1s and QSO2s.Finally I will present a comparison of star-formation in QSO1s and QSO2s. For both QSO1s and QSO2s 3stimates of star-formation rates that are based on the total IR continuum emission correlate with those based on the 11.3 micron PAH feature. However, for the QSO1s, star-formation rates estimated from the FIR continuum are higher than those estimated from the 11.3 micron PAH emission. This result can be attributed to a variety of factors including the possible destruction of the PAHs and that, in some sources, a fraction of the

  12. Confining hot spots in 3C 196 - Implications for QSO-companion galaxies

    NASA Technical Reports Server (NTRS)

    Brown, R. L.; Broderick, J. J.; Mitchell, K. J.

    1986-01-01

    VLBI observations of the extremely compact hot spot in the northern radio lobe of the QSO 3C 196 reveal the angular size of its smallest substructure to be 0.065 arcsec x 0.045 arcsec or about 300 pc at the redshift distance. The morphology of the hot spot and its orientation relative to the more diffuse radio emission suggest that it is formed by an oblique interaction between the nuclear QSO jet and circum-QSO cloud. The inferred density in this cloud, together with its apparent size, imply that the cloud contains a galactic mass, greater than a billion solar masses of gas. The effect of the jet will be to hasten gravitational collapse of the cloud. If many QSOs such as 3C 196 are formed or found in gas-rich environments, the QSO radio phase may commonly stimulate the metamorphosis of circum-QSO gas to QSO-companion galaxies or it may play a significant part in catalyzing star formation in existing companions.

  13. Confining hot spots in 3C 196 - implications for QSO-companion galaxies

    SciTech Connect

    Brown, R.L.; Broderick, J.J.; Mitchell, K.J.

    1986-07-01

    VLBI observations of the extremely compact hot spot in the northern radio lobe of the QSO 3C 196 reveal the angular size of its smallest substructure to be 0.065 arcsec x 0.045 arcsec or about 300 pc at the redshift distance. The morphology of the hot spot and its orientation relative to the more diffuse radio emission suggest that it is formed by an oblique interaction between the nuclear QSO jet and circum-QSO cloud. The inferred density in this cloud, together with its apparent size, imply that the cloud contains a galactic mass, greater than a billion solar masses of gas. The effect of the jet will be to hasten gravitational collapse of the cloud. If many QSOs such as 3C 196 are formed or found in gas-rich environments, the QSO radio phase may commonly stimulate the metamorphosis of circum-QSO gas to QSO-companion galaxies or it may play a significant part in catalyzing star formation in existing companions. 30 references.

  14. Understanding the Relations between QSOs and Their Host Galaxies from Combined HST Imaging and VLT Spectroscopy

    NASA Astrophysics Data System (ADS)

    Letawe, Y.; Magain, P.; Letawe, G.; Courbin, F.; Hutsemékers, D.

    2008-06-01

    The host galaxies of six nearby QSOs are studied on the basis of high-resolution HST optical images and spatially resolved VLT slit spectra. The gas ionization and velocity are mapped as a function of the distance to the central QSO. In the majority of the cases, the QSO significantly contributes to the gas ionization in its whole host galaxy, and sometimes even outside. Reflection or scattering of the QSO Hα line from remote regions of the galaxy is detected in several instances. The line shifts show that, in all cases, the matter responsible for the light reflection moves away from the QSO, likely accelerated by its radiation pressure. The two faintest QSOs reside in spirals, with some signs of a past gravitational perturbation. One of the intermediate-luminosity QSOs resides in a massive elliptical containing gas ionized (and probably pushed away) by the QSO radiation. The other medium-power object is found in a spiral galaxy displaying complex velocity structure, with the central QSO moving with respect to the bulge, probably as a result of a galactic collision. The two most powerful objects are involved in violent gravitational interactions, and one of them has no detected host. These results suggest that (1) large-scale phenomena, such as galactic collisions, are closely related to the triggering and the feeding of the QSO and (2) once ignited, the QSO has significant influence on its large-scale neighborhood (often the whole host and sometimes further away). Based on observations made with the Nasa/ESA Hubble Space Telescope (Cycle 13 proposal 10238), and with ANTU/UT1 at ESO-Paranal observatory in Chile [programs 65.P-0361(A) and 66.B-0139(A)].

  15. The host galaxies of quasi-stellar objects

    NASA Astrophysics Data System (ADS)

    Hamilton, Timothy Scott

    The results of an archival study of 71 medium-redshift QSOs observed with the Wide Field Planetary Camera 2 on board the Hubble Space Telescope are presented. The QSOs have magnitudes MV ≤ -23 mag (total nuclear + host light) and red shifts 0.06 ≤ z ≤ 0.46, with no additional criteria imposed. For each object, the nuclear light component is subtracted, using two-dimensional image fits, and the luminosity and size of the underlying host galaxy are determined by fitting both an r1/4 and an exponential light profile, which represent a bulge and disk component, respectively. The total number of objects considered is more than triple that of previous studies, and the general QSO population for redshifts z ≤ 0.46 is reasonably sampled. A luminosity function which is not grossly affected by selection criteria is derived for the QSO host galaxies. This luminosity function is compared with that of normal galaxies and a ratio of luminosity functions for QSO hosts and normal galaxies is derived. The logarithm of this ratio follows a nearly straight line when plotted against galaxy magnitude. Previous results which indicate that QSO hosts are more luminous than typical bright galaxies are confirmed. The relationship between host and nuclear luminosity is studied in the context of morphology and radio-loudness. The surface brightnesses of the host galaxies are compared to the known relationships between the effective surface magnitude and size of Brightest Cluster Galaxies. The surface brightness distribution is also examined in the context of radio-loudness and the merger history of the hosts. Black hole masses for a subset of the QSOs are taken from the literature and used to calculate the Eddington limit for those objects. The black hole mass, the nuclear luminosity, and the nuclear luminosity as a fraction of the Eddington limit are examined as functions of each other. Multi-parameter analyses are performed using Principal Components Analysis to search for

  16. The low-metallicity QSO HE 2158 - 0107: a massive galaxy growing by accretion of nearly pristine gas from its environment?

    NASA Astrophysics Data System (ADS)

    Husemann, B.; Wisotzki, L.; Jahnke, K.; Sánchez, S. F.

    2011-11-01

    The metallicities of active galactic nuclei (AGN) are usually well above solar in their narrow-line regions, often reaching up to several times solar in their broad-line regions independent of redshift. Low-metallicity AGN are rare objects that have so far always been associated with low-mass galaxies hosting low-mass black holes (MBH106M⊙). We present integral field spectroscopy data of the low-redshift (z = 0.212) quasi-stellar object (QSO) HE 2158 - 0107 for which we find strong evidence of sub-solar NLR metallicities associated with a massive black hole (MBH ~ 3 × 108M⊙). The QSO is surrounded by a large extended emission-line region reaching out to 30 kpc from the QSO in a tail-like geometry. We present optical and near-infrared images and investigate the properties of the host galaxy. The host of HE 2158 - 0107 is most likely a very compact bulge-dominated galaxy with a size of re ~ 1.4 kpc. The multi-colour spectral energy distribution (SED) of the host is quite blue, indicative of a significant young age stellar population formed within the last 1 Gyr. A 3σ upper limit of Lbulge,H < 4.5 × 1010L ⊙ ,H for the H-band luminosity and a corresponding stellar mass upper limit of Mbulge < 3.4 × 1010M⊙ show that the host is offset from the local black hole-bulge relations. This is independently supported by the kinematics of the gas. Although the stellar mass of the host galaxy is lower than expected, it cannot explain the exceptionally low metallicity of the gas. We suggest that the extended emission-line region and the galaxy growth are caused by the infall of nearly pristine gas from the environment of the QSO host. Minor mergers of low-metallicity dwarf galaxies or the theoretically predicted smooth accretion of cold (~ 104 K) gas are both potential drivers behind that process. Because the metallicity of the gas in the QSO narrow-line region is much lower than expected, we suspect that the external gas has already reached the galaxy centre and may

  17. The MG II absorption system in the QSO PKS 2128-12 - A galaxy disc/halo with a radius of 65 KPC

    NASA Astrophysics Data System (ADS)

    Bergeron, J.

    1986-01-01

    An imaging survey of the field around QSO PKS 2128-12, a QSO with low redshift narrow Mg II absorption line systems, is performed to verify the assumption that sharp metal-rich absorption systems found in the spectra of QSO's arise in intervening materials. The absorber has a redshift, z = 0.4299, that is smaller than that of the QSO emission redshift. The closest galaxy to the QSO, lies 64 kpc north-east of it, and has a redshift equal to that of the absorber. It is gas-rich, and its V and red magnitudes are about those expected for a spiral galaxy. Since the absorbing gas is found to have a small velocity dispersion, fairly high abundances and column densities, and a moderate degree of ionization, it is more likely associated with material in the disc of this galaxy than with a large surrounding halo. This QSO-galaxy pair increases by a factor of four the projected distance from a galaxy center at which absorbing ionized gas has been detected, strongly favoring the assumption of intervening galaxies at least for moderately ionized absorbers.

  18. INTERMEDIATE-AGE STELLAR POPULATIONS IN CLASSICAL QUASI-STELLAR OBJECT HOST GALAXIES

    SciTech Connect

    Canalizo, Gabriela; Stockton, Alan E-mail: stockton@ifa.hawaii.edu

    2013-08-01

    Although mergers and starbursts are often invoked in the discussion of quasi-stellar object (QSO) activity in the context of galaxy evolution, several studies have questioned their importance or even their presence in QSO host galaxies. Accordingly, we are conducting a study of z {approx} 0.2 QSO host galaxies previously classified as passively evolving elliptical galaxies. We present deep Keck/LRIS spectroscopy of a sample of 15 hosts and model their stellar absorption spectra using stellar synthesis models. The high signal-to-noise ratio of our spectra allows us to break various degeneracies that arise from different combinations of models, varying metallicities, and contamination from QSO light. We find that none of the host spectra can be modeled by purely old stellar populations and that the majority of the hosts (14/15) have a substantial contribution from intermediate-age populations with ages ranging from 0.7 to 2.4 Gyr. An average host spectrum is strikingly well fit by a combination of an old population and a 2.1 (+0.5, -0.7) Gyr population. The morphologies of the host galaxies suggest that these aging starbursts were induced during the early stages of the mergers that resulted in the elliptical-shaped galaxies that we observe. The current active galactic nucleus activity likely corresponds to the late episodes of accretion predicted by numerical simulations, which occur near the end of the mergers, whereas earlier episodes may be more difficult to observe due to obscuration. Our off-axis observations prevent us from detecting any current star formation or young stellar populations that may be present in the central few kiloparsecs.

  19. Suzaku observations of the type 2 QSO in the central galaxy of the Phoenix cluster

    SciTech Connect

    Ueda, Shutaro; Hayashida, Kiyoshi; Anabuki, Naohisa; Nakajima, Hiroshi; Koyama, Katsuji; Tsunemi, Hiroshi

    2013-11-20

    We report the Suzaku/XIS and HXD and Chandra/ACIS-I results on the X-ray spectra of the Phoenix cluster at the redshift z = 0.596. The spectrum of the intracluster medium (ICM) is well reproduced with the emissions from low-temperature (∼3.0 keV and ∼0.76 solar) and high-temperature (∼11 keV and ∼0.33 solar) plasmas; the former is localized at the cluster core, while the latter distributes over the cluster. In addition to these ICM emissions, a strongly absorbed power-law component is found, which is due to an active galactic nucleus (AGN) in the cluster center. The absorption column density and unobscured luminosity of the AGN are ∼3.2 × 10{sup 23} cm{sup –2} and ∼4.7 × 10{sup 45} erg s{sup –1} (2-10 keV), respectively. Furthermore, a neutral iron (Fe I) K-shell line is discovered for the first time with the equivalent width (EW) of ∼150 eV at the rest frame. The column density and the EW of the Fe I line are exceptionally large for such a high-luminosity AGN, and hence the AGN is classified as a type 2 quasi-stellar object (QSO). We speculate that a significant fraction of the ICM cooled gas would be consumed to maintain the torus and to activate the type 2 QSO. The Phoenix cluster has a massive starburst in the central galaxy, indicating that suppression in the cooling flow is less effective. This may be because the onset of the latest AGN feedback has occurred recently and has not yet been effective. Alternatively, the AGN feedback is predominantly in radiative mode, not in kinetic mode, and the torus may work as a shield to reduce its effect.

  20. Low-redshift quasars in the SDSS Stripe 82. Host galaxy colours and close environment

    NASA Astrophysics Data System (ADS)

    Bettoni, D.; Falomo, R.; Kotilainen, J. K.; Karhunen, K.; Uslenghi, M.

    2015-12-01

    We present a photometrical and morphological multicolour study of the properties of low-redshift (z < 0.3) quasar hosts based on a large and homogeneous data set of quasars derived from the Sloan Digital Sky Survey (DR7). We used quasars that were imaged in the SDSS Stripe82 that is up to 2 mag deeper than standard Sloan images. This sample is part of a larger data set of ˜400 quasars at z < 0.5 for which both the host galaxies and their galaxy environments were studied. For 52 quasars, we undertake a study of the colour of the host galaxies and of their close environments in the u, g, r, i and z bands. We are able to resolve almost all the quasars in the sample in the filters g, r, i and z and also in u for about 50 per cent of the targets. We found that the mean colours of the QSO host galaxy (g - i = 0.82 ± 0.26; r - i = 0.26 ± 0.16 and u - g = 1.32 ± 0.25) are very similar to the values of a sample of inactive galaxies matched in terms of redshift and galaxy luminosity with the quasar sample. There is a suggestion that the most massive QSO hosts have bluer colours. Both quasar hosts and the comparison sample of inactive galaxies have candidates of close (<50 kpc) companion galaxies for ˜30 per cent of the sources with no significant difference between active and inactive galaxies. We do not find significant correlation between the central black hole (BH) mass and the quasar host luminosity that appears to be extra luminous at a given BH mass with respect to the local relation (MBH - Mhost) for inactive galaxies. This confirms previous suggestion that a substantial disc component, not correlated with the BH mass, is present in the galaxies hosting low-z quasars. These results support a scenario where the activation of the nucleus has negligible effects on the global structural and photometrical properties of the hosting galaxies.

  1. Host Galaxy Identification for Supernova Surveys

    NASA Astrophysics Data System (ADS)

    Gupta, Ravi R.; Kuhlmann, Steve; Kovacs, Eve; Spinka, Harold; Kessler, Richard; Goldstein, Daniel A.; Liotine, Camille; Pomian, Katarzyna; D'Andrea, Chris B.; Sullivan, Mark; Carretero, Jorge; Castander, Francisco J.; Nichol, Robert C.; Finley, David A.; Fischer, John A.; Foley, Ryan J.; Kim, Alex G.; Papadopoulos, Andreas; Sako, Masao; Scolnic, Daniel M.; Smith, Mathew; Tucker, Brad E.; Uddin, Syed; Wolf, Rachel C.; Yuan, Fang; Abbott, Tim M. C.; Abdalla, Filipe B.; Benoit-Lévy, Aurélien; Bertin, Emmanuel; Brooks, David; Carnero Rosell, Aurelio; Carrasco Kind, Matias; Cunha, Carlos E.; da Costa, Luiz N.; Desai, Shantanu; Doel, Peter; Eifler, Tim F.; Evrard, August E.; Flaugher, Brenna; Fosalba, Pablo; Gaztañaga, Enrique; Gruen, Daniel; Gruendl, Robert; James, David J.; Kuehn, Kyler; Kuropatkin, Nikolay; Maia, Marcio A. G.; Marshall, Jennifer L.; Miquel, Ramon; Plazas, Andrés A.; Romer, A. Kathy; Sánchez, Eusebio; Schubnell, Michael; Sevilla-Noarbe, Ignacio; Sobreira, Flávia; Suchyta, Eric; Swanson, Molly E. C.; Tarle, Gregory; Walker, Alistair R.; Wester, William

    2016-12-01

    Host galaxy identification is a crucial step for modern supernova (SN) surveys such as the Dark Energy Survey and the Large Synoptic Survey Telescope, which will discover SNe by the thousands. Spectroscopic resources are limited, and so in the absence of real-time SN spectra these surveys must rely on host galaxy spectra to obtain accurate redshifts for the Hubble diagram and to improve photometric classification of SNe. In addition, SN luminosities are known to correlate with host-galaxy properties. Therefore, reliable identification of host galaxies is essential for cosmology and SN science. We simulate SN events and their locations within their host galaxies to develop and test methods for matching SNe to their hosts. We use both real and simulated galaxy catalog data from the Advanced Camera for Surveys General Catalog and MICECATv2.0, respectively. We also incorporate “hostless” SNe residing in undetected faint hosts into our analysis, with an assumed hostless rate of 5%. Our fully automated algorithm is run on catalog data and matches SNe to their hosts with 91% accuracy. We find that including a machine learning component, run after the initial matching algorithm, improves the accuracy (purity) of the matching to 97% with a 2% cost in efficiency (true positive rate). Although the exact results are dependent on the details of the survey and the galaxy catalogs used, the method of identifying host galaxies we outline here can be applied to any transient survey.

  2. Host Galaxy Identification for Supernova Surveys

    SciTech Connect

    Gupta, Ravi R.; Kuhlmann, Steve; Kovacs, Eve; Spinka, Harold; Kessler, Richard; Goldstein, Daniel A.; Liotine, Camille; Pomian, Katarzyna; D’Andrea, Chris B.; Sullivan, Mark; Carretero, Jorge; Castander, Francisco J.; Nichol, Robert C.; Finley, David A.; Fischer, John A.; Foley, Ryan J.; Kim, Alex G.; Papadopoulos, Andreas; Sako, Masao; Scolnic, Daniel M.; Smith, Mathew; Tucker, Brad E.; Uddin, Syed; Wolf, Rachel C.; Yuan, Fang; Abbott, Tim M. C.; Abdalla, Filipe B.; Benoit-Lévy, Aurélien; Bertin, Emmanuel; Brooks, David; Rosell, Aurelio Carnero; Kind, Matias Carrasco; Cunha, Carlos E.; Costa, Luiz N. da; Desai, Shantanu; Doel, Peter; Eifler, Tim F.; Evrard, August E.; Flaugher, Brenna; Fosalba, Pablo; Gaztañaga, Enrique; Gruen, Daniel; Gruendl, Robert; James, David J.; Kuehn, Kyler; Kuropatkin, Nikolay; Maia, Marcio A. G.; Marshall, Jennifer L.; Miquel, Ramon; Plazas, Andrés A.; Romer, A. Kathy; Sánchez, Eusebio; Schubnell, Michael; Sevilla-Noarbe, Ignacio; Sobreira, Flávia; Suchyta, Eric; Swanson, Molly E. C.; Tarle, Gregory; Walker, Alistair R.; Wester, William

    2016-11-08

    Host galaxy identification is a crucial step for modern supernova (SN) surveys such as the Dark Energy Survey (DES) and the Large Synoptic Survey Telescope (LSST), which will discover SNe by the thousands. Spectroscopic resources are limited, so in the absence of real-time SN spectra these surveys must rely on host galaxy spectra to obtain accurate redshifts for the Hubble diagram and to improve photometric classification of SNe. In addition, SN luminosities are known to correlate with host-galaxy properties. Therefore, reliable identification of host galaxies is essential for cosmology and SN science. We simulate SN events and their locations within their host galaxies to develop and test methods for matching SNe to their hosts. We use both real and simulated galaxy catalog data from the Advanced Camera for Surveys General Catalog and MICECATv2.0, respectively. We also incorporate "hostless" SNe residing in undetected faint hosts into our analysis, with an assumed hostless rate of 5%. Our fully automated algorithm is run on catalog data and matches SNe to their hosts with 91% accuracy. We find that including a machine learning component, run after the initial matching algorithm, improves the accuracy (purity) of the matching to 97% with a 2% cost in efficiency (true positive rate). Although the exact results are dependent on the details of the survey and the galaxy catalogs used, the method of identifying host galaxies we outline here can be applied to any transient survey.

  3. A Morphological And Spectroscopic Atlas Of Emission Line Galaxies With QSO-Like Colors

    NASA Astrophysics Data System (ADS)

    Liu, Charles; Prescott, M.; Carroll, P.; Colon, A.; Roberts, R.; Wong, H.; Capak, P.; Impey, C.; Mobasher, B.; Scoville, N.; COSMOS Collaboration

    2007-12-01

    We present Hubble ACS I814 images, Subaru i images, and 3200A- 9000A optical spectroscopy for a sample of 139 narrow emission-line galaxies with quasar-like optical colors in the COSMOS Hubble Treasury field. These galaxies were all originally identified as quasar candidates in the Sloan Digital Sky Survey, primarily by their location in optical four-color space and secondarily by radio continuum emission. The sample shows the full range of galaxy morphologies, including very luminous galaxies and low surface brightness objects as well as compact dwarf galaxies. At least 17 of the galaxies (12% of the sample) have a close companion of comparable size and strong tidal features, indicating an ongoing merger or interaction. As an initial analysis, we compare the spectroscopic redshifts of these galaxies with their photometrically determined redshifts, and find no significant difference between the accuracy of this sample's photometric redshifts and that of the COSMOS galaxy population as a whole.

  4. AGN Host Galaxy Properties And Mass Function

    NASA Astrophysics Data System (ADS)

    Bongiorno, Angela

    2016-10-01

    Supermassive black hole growth, nuclear activity, and galaxy evolution have been found to be closely related. In the context of AGN-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 AGN feedback as possible responsible mechanism for galaxy quenching.

  5. Imaging the host galaxies of high-redshift radio-quiet QSOs

    NASA Technical Reports Server (NTRS)

    Lowenthal, James D.; Heckman, Timothy M.; Lehnert, Matthew, D.; Elias, J. H.

    1995-01-01

    We present new deep K-band and optical images of four radio-quiet QSOs at z approximately = 1 and six radio-quiet QSOs at z approximately = 2.5, as well as optical images only of six more at z approximately = 2.5. We have examined the images carefully for evidence of extended 'fuzz' from any putative QSO host galaxy. None of the z approximately = 2.5 QSOs shows any extended emission, and only two of the z approximately = 1 QSOs show marginal evidence for extended emission. Our 3 sigma detection limits in the K images, m(sub K) approximately = 21 for an isolated source, would correspond approximately to an unevolved L(sup star) elliptical galaxy at z = 2.5 or 2-3 mag fainter than an L(sup star) elliptical at z = 1, although our limits on host galaxy light are weaker than this due to the difficulty of separating galaxy light from QSO light. We simulate simple models of disk and elliptical host galaxies, and find that the marginal emission around the two z approximately = 1 QSOs can be explained by disks or bulges that are approximately 1-2 mag brighter than an unevolved L(sup star) galaxy in one case and approximately 1.5-2.5 mag brighter than L(sub star) in the other. For two other z approximately = 1 QSOs, we have only upper limits (L approximately = L(sup star)). The hosts of the high-redshift sample must be no brighter than about 3 mag above an unevolved L(sup star) galaxy, and are at least 1 magnitude fainter than the hosts of radio-loud QSOs at the same redshift. If the easily detected K-band light surrounding a previous sample of otherwise similar but radio-loud QSOs is starlight, then it must evolve on timescales of greater than or approximately equal to 10(exp 8) yr (e.g., Chambers & Charlot 1990); therefore our non-detection of host galaxy fuzz around radio-quiet QSOs supports the view that high-redshift radio-quiet and radio-loud QSOs inhabit different host objects, rather than being single types of objects that turn their radio emission on and off over

  6. Black hole accretion and host galaxies of obscured quasars in XMM-COSMOS

    NASA Astrophysics Data System (ADS)

    Mainieri, V.; Bongiorno, A.; Merloni, A.; Aller, M.; Carollo, M.; Iwasawa, K.; Koekemoer, A. M.; Mignoli, M.; Silverman, J. D.; Bolzonella, M.; Brusa, M.; Comastri, A.; Gilli, R.; Halliday, C.; Ilbert, O.; Lusso, E.; Salvato, M.; Vignali, C.; Zamorani, G.; Contini, T.; Kneib, J.-P.; Le Fèvre, O.; Lilly, S.; Renzini, A.; Scodeggio, M.; Balestra, I.; Bardelli, S.; Caputi, K.; Coppa, G.; Cucciati, O.; de la Torre, S.; de Ravel, L.; Franzetti, P.; Garilli, B.; Iovino, A.; Kampczyk, P.; Knobel, C.; Kovač, K.; Lamareille, F.; Le Borgne, J.-F.; Le Brun, V.; Maier, C.; Nair, P.; Pello, R.; Peng, Y.; Perez Montero, E.; Pozzetti, L.; Ricciardelli, E.; Tanaka, M.; Tasca, L.; Tresse, L.; Vergani, D.; Zucca, E.; Aussel, H.; Capak, P.; Cappelluti, N.; Elvis, M.; Fiore, F.; Hasinger, G.; Impey, C.; Le Floc'h, E.; Scoville, N.; Taniguchi, Y.; Trump, J.

    2011-11-01

    Aims: We explore the connection between black hole growth at the center of obscured quasars selected from the XMM-COSMOS survey and the physical properties of their host galaxies. We study a bolometric regime ( ⟨ Lbol ⟩ = 8 × 1045 erg s-1) where several theoretical models invoke major galaxy mergers as the main fueling channel for black hole accretion. Methods: To derive robust estimates of the host galaxy properties, we use an SED fitting technique to distinguish the AGN and host galaxy emission. We evaluate the effect on galaxy properties estimates of being unable to remove the nuclear emission from the SED. The superb multi-wavelength coverage of the COSMOS field allows us to obtain reliable estimates of the total stellar masses and star formation rates (SFRs) of the hosts. We supplement this information with a morphological analysis of the ACS/HST images, optical spectroscopy, and an X-ray spectral analysis. Results: We confirm that obscured quasars mainly reside in massive galaxies (M ⋆ > 1010M⊙) and that the fraction of galaxies hosting such powerful quasars monotonically increases with the stellar mass. We stress the limitation of the use of rest-frame color - magnitude diagrams as a diagnostic tool for studying galaxy evolution and inferring the influence that AGN activity can have on such a process. We instead use the correlation between SFR and stellar mass found for star-forming galaxies to discuss the physical properties of the hosts. We find that at z ~ 1, ≈62% of Type-2 QSOs hosts are actively forming stars and that their rates are comparable to those measured for normal star-forming galaxies. The fraction of star-forming hosts increases with redshift: ≈ 71% at z ~ 2, and 100% at z ~ 3. We also find that the evolution from z ~ 1 to z ~ 3 of the specific SFR of the Type-2 QSO hosts is in excellent agreement with that measured for star-forming galaxies. From the morphological analysis, we conclude that most of the objects are bulge

  7. THE GALAXY ENVIRONMENT OF A QSO AT z {approx} 5.7

    SciTech Connect

    Banados, Eduardo; Venemans, Bram; Walter, Fabian; Kurk, Jaron; Overzier, Roderik; Ouchi, Masami

    2013-08-20

    High-redshift quasars are believed to reside in massive halos in the early universe and should therefore be located in fields with overdensities of galaxies, which are thought to evolve into galaxy clusters seen in the local universe. However, despite many efforts, the relationship between galaxy overdensities and z {approx} 6 quasars is ambiguous. This can possibly be attributed to the difficulty of finding galaxies with accurate redshifts in the vicinity of z {approx} 6 quasars. So far, overdensity searches around z {approx} 6 quasars have been based on studies of Lyman break galaxies (LBGs), which probe a redshift range of {Delta}z Almost-Equal-To 1. This range is large enough to select galaxies that may not be physically related to the quasar. We use deep narrow- and broadband imaging to study the environment of the z = 5.72 quasar ULAS J0203+0012. The redshift range probed by our narrow-band selection of Lyman alpha emitters (LAEs) is {Delta}z Almost-Equal-To 0.1, which is significantly narrower than the LBG searches. This is the first time that LAEs were searched for near a z {approx} 6 quasar, in an effort to provide clues about the environments of quasars at the end of the epoch of reionization. We find no enhancement of LAEs in the surroundings of ULAS J0203+0012 in comparison with blank fields. We explore different explanations and interpretations for this non-detection of a galaxy overdensity, including that (1) the strong ionization from the quasar may prevent galaxy formation in its immediate vicinity and (2) high-redshift quasars may not reside in the center of the most massive dark matter halos.

  8. Optical imaging of the low redshift superluminous QSO 1821 + 643

    SciTech Connect

    Hutchings, J.B.; Neff, S.G. NASA, Goddard Space Flight Center, Greenbelt, MD )

    1991-06-01

    Optical imaging is presented of the luminous z = 0.3 QSO 1821 + 643, with resolution 1.0 and 0.4 arcsec. The host galaxy is resolved and seen to be large, featureless, and red, with slightly displaced outer isophotes. The nucleus is unusually red. There is a rich cluster of galaxies in the field which is probably at a much higher redshift, and extended nebulosity from a nearby star. These results and the IR properties are discussed in terms of a mature merger of a luminous galaxy in which there is still a considerable amount of central dust and molecular clouds. 8 refs.

  9. Optical imaging of the low redshift superluminous QSO 1821 + 643

    NASA Technical Reports Server (NTRS)

    Hutchings, J. B.; Neff, S. G.

    1991-01-01

    Optical imaging is presented of the luminous z = 0.3 QSO 1821 + 643, with resolution 1.0 and 0.4 arcsec. The host galaxy is resolved and seen to be large, featureless, and red, with slightly displaced outer isophotes. The nucleus is unusually red. There is a rich cluster of galaxies in the field which is probably at a much higher redshift, and extended nebulosity from a nearby star. These results and the IR properties are discussed in terms of a mature merger of a luminous galaxy in which there is still a considerable amount of central dust and molecular clouds.

  10. Apparent brightness distribution of GRB host galaxies

    NASA Astrophysics Data System (ADS)

    Bagoly, Zsolt; Rácz, István I.; Balázs, Lajos G.; Horváth, István; Tóth, L. Viktor

    We studied the unbiased optical brightness distribution which was calculated from the survival analysis of host galaxies (HGs) data and its relationship with the Swift GRB data of the host galaxies observed by the Keck telescope. Based on the sample obtained from merging the Swift GRB table and the Keck optical data we also studied the dependence of this distribution on the GRB's data. Finally, we compared the HGs distribution with standard galaxies distribution of the DEEP2 redshift survey and checked the result with the VIPERS catalogue too.

  11. Detection of neutral hydrogen emission and optical nebulosity in the low redshift QSO 0351+026

    NASA Technical Reports Server (NTRS)

    Bothun, G. D.; Chanan, G. A.; Romanishin, W.; Margon, B.; Schommer, R. A.

    1982-01-01

    Spectroscopy, photometry, and imaging of the X-ray source 0351+026 are consistent with an active nucleus with the spectrum of a QSO or type I Seyfert, embedded in a low luminosity host galaxy of colors similar to M31. The H I observations reveal a tremendous amount of neutral gas associated with the system, M(H I)/L(B) = 15 in solar units, and the velocity width of the feature is 1500 km/s. Both parameters substantially exceed those seen in other galaxies and interacting pairs. The unique H I properties of the system combined with the presence of an active nucleus with QSO-like features is a tantalizing, but poorly understood, combination. At slightly larger redshift and thus inferior angular scale, this object would be indistinguishable from a QSO in its optical and X-ray characteristics.

  12. In Search of Quasar Host Galaxies

    NASA Astrophysics Data System (ADS)

    Young, Jason; Eracleous, M.; Gronwall, C.; Shemmer, O.; Netzer, H.; Sturm, E.; Ciardullo, R.

    2011-01-01

    We present a study of the morphology and intensity of star formation in the host galaxies of eight Palomar-Green quasars using observations with the Hubble Space Telescope. Accretion-powered and star formation activity have been shown to coincide, motivating us to search for the star-forming regions in the host galaxies of quasars and to determine the star-formation rates. In this work we use calibrated narrow band emission line (H-beta and Pa-alpha) WFPC2 and NICMOS images as maps for total star formation rate. The main challenge in imaging quasar host galaxies is the separation of the quasar light from the galaxy light, especially in the case of z approximately 0.1 quasars in WFPC2 images where the PSF radius closely matches the expected host scale radius. To this this end we present a novel technique for image decomposition and subtraction of quasar light, which we have validated through extensive simulations using artificial quasar+galaxy images. The other significant challenge in mapping and measuring star forming regions is correcting for extinction, which we address using extinction maps created from the Pa-alpha/H-beta ratio. To determine the source of excitation, we utilize H-beta along with [OIII]5007 and [OII]3727 images in diagnostic line ratio (BPT) diagrams. We detect extended line emission in our targets on scales of order 1-2 kpc. A preliminary analysis suggests star formation rates of order 10 solar masses per year.

  13. Host Galaxies of z=4 Quasars

    NASA Astrophysics Data System (ADS)

    McLeod, Kim K.; Bechtold, J.

    2010-01-01

    We have undertaken a project to investigate the host galaxies and environments of a sample of quasars at z 4. In this paper, we describe deep near-infrared imaging of 34 targets using the Magellan I and Gemini North telescopes. We discuss in detail special challenges of distortion and nonlinearity that must be addressed when performing PSF subtraction with data from these telescopes and their IR cameras, especially in very good seeing. We derive black hole masses from emission-line spectroscopy, and we calculate accretion rates from our Ks-band photometry, which directly samples the rest-frame B for these objects. We introduce a new isophotal diameter technique for estimating host galaxy luminosities. We report the detection of four host galaxies on our deepest, sharpest images, and present upper limits for the others. We find that if host galaxies passively evolve such that they brighten by 2 magnitudes or more in the rest-frame B band between the present and z=4, then high-z hosts are less massive at a given black hole mass than are their low-z counterparts. We argue that the most massive hosts plateau at < 10L*. We estimate the importance of selection effects on this survey and the subsequent limitations of our conclusions. These results are in broad agreement with recent semi-analytical models for the formation of luminous quasars and their host spheroids by mergers of gas-rich galaxies, with significant dissipation, and self-regulation of black hole growth and star-formation by the burst of merger-induced quasar activity.

  14. Apparent brightness distribution of GRB host galaxies

    NASA Astrophysics Data System (ADS)

    Bagoly, Zsolt; Racz, Istvan; Gyorgy Balazs, Lajos; Toth, Viktor; Horvath, Istvan

    2015-08-01

    We studied the relationship between the Swift GRB data and the optical brightness of the host galaxy measured by the Keck telescope. We calculated the unbiased distribution of the host's optical brightness by making use the survival analysis. Based on the sample obtained from merging the Swift GRB table and the Keck optical data we studied also the dependence of this distribution on the GRB's data.

  15. The Spiral Structure of AGN Host Galaxies

    NASA Astrophysics Data System (ADS)

    Kennefick, J.; Barrows, R. S.; Hughes, J. A.; Schilling, A.; Davis, B.; Shields, D.; Madey, A.; Kennefick, D.; Lacy, C.; Seigar, M.

    2014-03-01

    Recent work has uncovered a correlation between the black hole mass, M, in the centers of local spiral galaxies and the pitch angles, P, of their spiral arms. We propose to test this M-P correlation at moderate to high redshifts, using a sample of active galaxies selected from the Great Observatories Origins Survey and the Sloan Digital Sky Survey showing evidence for spiral structure in their host galaxies. The mass of the central black holes are estimated using the Hβ or Mg II lines in existing spectra using luminosity-radius scaling relations. Pitch angles are measured using an iterative 2D FFT algorithm. The aim is to establish this M-P relation beyond our local epoch, test for evolution in its form, and eventually to compute a BH mass function for late-type galaxies out to moderate redshifts.

  16. 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 0.3host 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.

  17. Host Galaxies of z = 4 Quasars

    NASA Astrophysics Data System (ADS)

    McLeod, K. K.; Bechtold, Jill

    2009-10-01

    We have undertaken a project to investigate the host galaxies and environments of a sample of quasars at z ~ 4. In this paper, we describe deep near-infrared imaging of 34 targets using the Magellan I and Gemini North telescopes. We discuss in detail special challenges of distortion and nonlinearity that must be addressed when performing point-spread function (PSF) subtraction with data from these telescopes and their IR cameras, especially in very good seeing. We derive black hole masses from emission-line spectroscopy, and we calculate accretion rates from our Ks -band photometry, which directly samples the rest frame B for these objects. We introduce a new isophotal diameter technique for estimating host galaxy luminosities. We report the detection of four host galaxies on our deepest, sharpest images, and present upper limits for the others. We find that if host galaxies passively evolve such that they brighten by 2 mag or more in the rest-frame B band between the present and z = 4, then high-z hosts are less massive at a given black hole mass than are their low-z counterparts. We argue that the most massive hosts plateau at lsim10 L*. We estimate the importance of selection effects on this survey and the subsequent limitations of our conclusions. These results are in broad agreement with recent semianalytical models for the formation of luminous quasars and their host spheroids by mergers of gas-rich galaxies, with significant dissipation, and self-regulation of black hole growth and star formation by the burst of merger-induced quasar activity. Based on data obtained with the 6.5 m Baade Telescope of the Magellan Telescope, located at the Las Campans Observatory, Chile. Based in part on data taken at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA, and was made possible by the generous financial support of the W. M. Keck Foundation.

  18. Spectral decomposition of broad-line agns and host galaxies

    SciTech Connect

    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.

    2005-09-01

    Using an eigenspectrum decomposition technique, we separate the host galaxy from the broad line active galactic nucleus (AGN) 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 AGN 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 AGN 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 AGN 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 AGNs 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 AGN and host galaxy eigencoefficients, possibly indicating a link between recent star formation and the onset of AGN activity. The catalog of spectral reconstruction parameters is available as an electronic table.

  19. Tomography of a Gamma-ray Burst Progenitor and its Host Galaxy

    NASA Technical Reports Server (NTRS)

    Castro-Tirado, Alberto J.; Moller, Palle; Garcia-Segura, Guillermo; Gorosabel, Javier; Perez, Enrique; deUgartePostigo, Antonio; Solano, Enrique; BarradoyNavascues, David; CastroCeron, Jose Marie; Kouveliotou, Chryssa

    2005-01-01

    We have obtained near-infrared and high-resolution optical spectroscopy of the bright afterglow of the very intense gamma-ray burst recorded on 2002, October 4 (GRB 021004). Besides of line emission in the near-IR allowing an independent measurement of the systemic redshift (z = 2.3304 plus or minus 0.0005), we find several absorption line groups spanning a range of about 3,000 kilometers per second in velocity relative to the redshift of the host galaxy. The absorption profiles are very complex with both velocity-broadened components extending over several 100 kilometers per second and narrow lines with velocity widths of only approximately 20 kilometers per second. By analogy with QSO absorption line studies, the relative velocities, widths, and degrees of ionization of the lines ("line-locking", "ionization-velocity correlation") show that the progenitor had both an extremely strong radiation field and several distinct mass loss phases (winds). These results are consistent with GRB progenitors being massive stars, such as Luminous Blue Variables (LBVs) or Wolf-Rayet stars, providing a detailed picture of the spatial and velocity structure of the GRB progenitor star at the time of explosion. The host galaxy is a prolific star-forming galaxy with a SFR of approximately 10 solar mass yr(sup -l).

  20. Deficiency of "Thin" Stellar Bars in Seyfert Host Galaxies.

    PubMed

    Shlosman; Peletier; Knapen

    2000-06-01

    Using all available major samples of Seyfert galaxies and their corresponding closely matched control samples of nonactive galaxies, we find that the bar ellipticities (or axial ratios) in Seyfert galaxies are systematically different from those in nonactive galaxies. Overall, there is a deficiency of bars with large ellipticities (i.e., "thin" or "strong" bars) in Seyfert galaxies compared to nonactive galaxies. Accompanied with a large dispersion due to small number statistics, this effect is strictly speaking at the 2 sigma level. To obtain this result, the active galaxy samples of near-infrared surface photometry were matched to those of normal galaxies in type, host galaxy ellipticity, absolute magnitude, and, to some extent, redshift. We discuss possible theoretical explanations of this phenomenon within the framework of galactic evolution, and, in particular, of radial gas redistribution in barred galaxies. Our conclusions provide further evidence that Seyfert hosts differ systematically from their nonactive counterparts on scales of a few kiloparsecs.

  1. Coevolution of Supermassive Black Holes and Their Host Galaxies

    NASA Astrophysics Data System (ADS)

    Hiner, Kyle Devon

    The role of black holes in galaxy evolution has come under intense scrutiny since it was discovered that every galaxy in the local universe contains a supermassive black hole (SMBH) at its nucleus. The existence of scaling relations between the SMBH and its host galaxy show that their presence is not coincidental, but rather that SMBHs and their hosts have a shared evolution. The nature of this coevolution is still debated with some proposing it to be a natural result of hierarchical merging models, while others invoke SMBH feedback mechanisms that couple BH growth with that of the host galaxy. In this dissertation, I examine different regimes of SMBH activity and host galaxy properties. I investigate a sample of post-starburst galaxies to gain insight into the morphological and spectrophotometric evolution of galaxies through galaxy interactions and mergers. I plot detailed comparisons of the galaxy kinematics as measured from different stellar populations. I also investigate post-starburst galaxies that simultaneously host an AGN. I develop a technique to study the properties of both the host galaxy and the SMBH in these objects, directly investigating the scaling relation between the two. I describe analysis performed on red quasars in another study that directly probes the scaling relations in the non-local universe. Lastly, I conduct SED fitting of quasars to illuminate the differences between two major spectral types, and investigate host galaxy properties including star formation. All of these projects focus on the relationship between the SMBH and host galaxy. I show that a range of galaxy interactions can lead to black hole growth and are part of galaxy evolution over cosmic time.

  2. AGN multi-wavelength identification and host galaxy properties

    NASA Astrophysics Data System (ADS)

    Azadi, Mojegan; Coil, Alison L.; MOSDEF Team; PRIMUS Team

    2017-01-01

    I present results on AGN identification, selection biases, and host galaxy properties at z~2.3 and results on the relation between AGN accretion and star formation activity at z~0.8. In the MOSDEF survey, with a sample of X-ray, IR, and optically selected AGN at z~2.3, using rest-frame optical spectra obtained with the Keck/MOSFIRE instrument, I find clear selection biases in identifying AGN at these wavelengths. There is a strong bias against identifying AGN at any wavelength in low mass galaxies, and an additional bias against identifying IR AGN in the most massive galaxies. While AGN hosts span a wide range of SFR, IR AGN are mainly in less dusty galaxies with relatively higher SFR and optical AGN are in dusty galaxies with relatively lower SFR in our sample. X-ray AGN 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 AGN in the PRIMUS survey. I do not find a significant correlation between SFR and AGN instantaneous luminosity. However, I find a weak but significant correlation between the average luminosity of AGN and SFR, which likely reflects that AGN luminosities vary on shorter timescales than host galaxies SFR. My results indicate that AGN are also often hosted by quiescent galaxies, and within both the star-forming and quiescent galaxy populations the probability of hosting an AGN 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 AGN of a given specific accretion rate. The probability of a galaxy hosting an AGN is constant across the main sequence of star formation, while in quiescent galaxies increases with SFR.

  3. AGN-host galaxy connection: multiwavelength study

    NASA Astrophysics Data System (ADS)

    Pović, M.; Sánchez-Portal, M.; García, A. M. Pérez; Bongiovanni, A.; Cepa, J.; Cepa

    2013-02-01

    The connection between active galactic nuclei (AGN) 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 AGN 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 AGN 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 AGN 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 AGN 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 AGN 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 AGN feedback mechanisms and evolving to red-sequence galaxies. More details on analysis and results presented here can be found in

  4. Deep imaging of high redshift QSO fields below the Lyman limit. II - Number counts and colors of field galaxies

    NASA Technical Reports Server (NTRS)

    Steidel, Charles C.; Hamilton, Donald

    1993-01-01

    We present an analysis of the number counts and colors of faint galaxies to about 26.5 mag in the fields of two high Galactic latitude, very-high-redshift QSOs. We concentrate on the general properties of the field galaxies at faint magnitudes. In particular, we readdress the faint galaxy number counts and colors as a function of apparent magnitude and we reexamine the possible contribution of very-high-redshift galaxies to the faint samples. We find that the number counts to R = 26 are well fitted by the relation log N(m) = 0.31R + C. The G-band counts for the same galaxies are consistent with the same slope fainter than G about 23.5, but exhibit a much steeper slope at brighter magnitudes. At R = 25.5, the differential number counts have reached about 1.2 x 10 exp 5/sq deg; the same surface density of galaxies is reached at G = 26.5. We confirm the existence of a gradual 'blueing' trend of the field galaxies toward fainter apparent magnitude; however, the blueing trend appears to extend only as faint as G about 24, fainter than which both the (G-R) and (U sub n-G) colors appear to level off. The mean colors of faint galaxies are considerably redder than flat spectrum. There are essentially no objects to R = 26 which have spectral energy distributions which are bluer than flat spectrum. The potential contribution of very-high-redshift galaxies may have been underestimated in previous analyses; the current data are consistent with the same population of relatively luminous galaxies at z about 3 as exist at z about 0.7.

  5. Radio Galaxy Zoo: host galaxies and radio morphologies derived from visual inspection

    NASA Astrophysics Data System (ADS)

    Banfield, J. K.; Wong, O. I.; Willett, K. W.; Norris, R. P.; Rudnick, L.; Shabala, S. S.; Simmons, B. D.; Snyder, C.; Garon, A.; Seymour, N.; Middelberg, E.; Andernach, H.; Lintott, C. J.; Jacob, K.; Kapińska, A. D.; Mao, M. Y.; Masters, K. L.; Jarvis, M. J.; Schawinski, K.; Paget, E.; Simpson, R.; Klöckner, H.-R.; Bamford, S.; Burchell, T.; Chow, K. E.; Cotter, G.; Fortson, L.; Heywood, I.; Jones, T. W.; Kaviraj, S.; López-Sánchez, Á. R.; Maksym, W. P.; Polsterer, K.; Borden, K.; Hollow, R. P.; Whyte, L.

    2015-11-01

    We present results from the first 12 months of operation of Radio Galaxy Zoo, which upon completion will enable visual inspection of over 170 000 radio sources to determine the host galaxy of the radio emission and the radio morphology. Radio Galaxy Zoo uses 1.4 GHz radio images from both the Faint Images of the Radio Sky at Twenty Centimeters (FIRST) and the Australia Telescope Large Area Survey (ATLAS) in combination with mid-infrared images at 3.4 μm from the Wide-field Infrared Survey Explorer (WISE) and at 3.6 μm from the Spitzer Space Telescope. We present the early analysis of the WISE mid-infrared colours of the host galaxies. For images in which there is >75 per cent consensus among the Radio Galaxy Zoo cross-identifications, the project participants are as effective as the science experts at identifying the host galaxies. The majority of the identified host galaxies reside in the mid-infrared colour space dominated by elliptical galaxies, quasi-stellar objects and luminous infrared radio galaxies. We also find a distinct population of Radio Galaxy Zoo host galaxies residing in a redder mid-infrared colour space consisting of star-forming galaxies and/or dust-enhanced non-star-forming galaxies consistent with a scenario of merger-driven active galactic nuclei (AGN) formation. The completion of the full Radio Galaxy Zoo project will measure the relative populations of these hosts as a function of radio morphology and power while providing an avenue for the identification of rare and extreme radio structures. Currently, we are investigating candidates for radio galaxies with extreme morphologies, such as giant radio galaxies, late-type host galaxies with extended radio emission and hybrid morphology radio sources.

  6. A low-luminosity type-1 QSO sample . IV. Molecular gas contents and conditions of star formation in three nearby Seyfert galaxies

    NASA Astrophysics Data System (ADS)

    Moser, Lydia; Krips, Melanie; Busch, Gerold; Scharwächter, Julia; König, Sabine; Eckart, Andreas; Smajić, Semir; García-Marin, Macarena; Valencia-S., Mónica; Fischer, Sebastian; Dierkes, Jens

    2016-03-01

    We present a pilot study of ~3'' resolution observations of low CO transitions with the Submillimeter Array in three nearby Seyfert galaxies, which are part of the low-luminosity quasi-stellar object (LLQSOs) sample consisting of 99 nearby (z = 0.06) type-1 active galactic nuclei (AGN) taken from the Hamburg/ESO quasi-stellar object (QSO) survey. Two sources were observed in 12CO(2-1) and 13CO(2-1) and the third in 12CO(3-2) and HCO+(4-3). None of the sources is detected in continuum emission. More than 80% of the 12CO detected molecular gas is concentrated within a diameter (FWHM) < 1.8 kpc. 13CO is tentatively detected, while HCO+ emission could not be detected. All three objects show indications of a kinematically decoupled central unresolved molecular gas component. The molecular gas masses of the three galaxies are in the range Mmol = (0.7-8.7) × 109M⊙. We give lower limits for the dynamical masses of Mdyn> 1.5 × 109M⊙ and for the dust masses of Mdust> 1.6 × 106M⊙. The R21 = 12CO/13CO(2-1) line luminosity ratios show Galactic values of R21 ~ 5-7 in the outskirts and R21 ≳ 20 in the central region, similar to starbursts and (ultra)luminous infrared galaxies ((U)LIRGs; i.e. LIRGs and ULIRGs), implying higher temperatures and stronger turbulence. All three sources show indications of 12CO(2-1)/12CO(1-0) ratios of ~0.5, suggesting a cold or diffuse gas phase. Strikingly, the 12CO(3-2)/(1-0) ratio of ~1 also indicates a higher excited phase. Since these galaxies have high infrared luminosities of LIR ≥ 1011L⊙ and seem to contain a circumnuclear starburst with minimum surface densities of gas and star formation rate (SFR) around Σmol = 50-550 M⊙pc-2 and ΣSFR = 1.1-3.1 M⊙ kpc-2 yr-1, we conclude that the interstellar medium in the centers of these LIRG Seyferts is strongly affected by violent star formation and better described by the ULIRG mass conversion factor.

  7. Dust effects on LGRB host galaxies in cosmological simulations

    NASA Astrophysics Data System (ADS)

    Bignone, L. A.; Pellizza, L. J.; Tissera, P. B.

    2016-08-01

    The very energetic long gamma-ray bursts (LGRBs) constitute an extremely important tool to study the cosmological evolution of the Universe up to very high redshift. In this work we study the properties of LGRB host galaxies using numerical simulations of galaxy formation. We combine the galaxy catalogue of a hydrodynamical cosmological simulation with a model for LGRBs, which includes constrains for the mass and metallicity of their progenitors. This allows us to analyse the chemical and physical properties of both LGRBs and their hosts. A current problem is to disentangle the bias introduced on the observed host properties by a possible metallicity dependence of the progenitors, from the selection effects produced by dust obscuration in the hosts. We explore this issue by modelling the effect of dust in host galaxies, using radiative transfer codes. In this work we present preliminary results of this research line.

  8. Galaxy Zoo: evidence for rapid, recent quenching within a population of AGN host galaxies

    NASA Astrophysics Data System (ADS)

    Smethurst, R. J.; Lintott, C. J.; Simmons, B. D.; Schawinski, K.; Bamford, S. P.; Cardamone, C. N.; Kruk, S. J.; Masters, K. L.; Urry, C. M.; Willett, K. W.; Wong, O. I.

    2016-12-01

    We present a population study of the star formation history of 1244 Type 2 active galactic nuclei (AGN) host galaxies, compared to 6107 inactive galaxies. A Bayesian method is used to determine individual galaxy star formation histories, which are then collated to visualize the distribution for quenching and quenched galaxies within each population. We find evidence for some of the Type 2 AGN host galaxies having undergone a rapid drop in their star formation rate within the last 2 Gyr. AGN feedback is therefore important at least for this population of galaxies. This result is not seen for the quenching and quenched inactive galaxies whose star formation histories are dominated by the effects of downsizing at earlier epochs, a secondary effect for the AGN host galaxies. We show that histories of rapid quenching cannot account fully for the quenching of all the star formation in a galaxy's lifetime across the population of quenched AGN host galaxies, and that histories of slower quenching, attributed to secular (non-violent) evolution, are also key in their evolution. This is in agreement with recent results showing that both merger-driven and non-merger processes are contributing to the co-evolution of galaxies and supermassive black holes. The availability of gas in the reservoirs of a galaxy, and its ability to be replenished, appear to be the key drivers behind this co-evolution.

  9. Discovery of a bright quasar without a massive host galaxy.

    PubMed

    Magain, Pierre; Letawe, Géraldine; Courbin, Frédéric; Jablonka, Pascale; Jahnke, Knud; Meylan, Georges; Wisotzki, Lutz

    2005-09-15

    A quasar is thought to be powered by the infall of matter onto a supermassive black hole at the centre of a massive galaxy. Because the optical luminosity of quasars exceeds that of their host galaxy, disentangling the two components can be difficult. This led in the 1990s to the controversial claim of the discovery of 'naked' quasars. Since then, the connection between quasars and galaxies has been well established. Here we report the discovery of a quasar lying at the edge of a gas cloud, whose size is comparable to that of a small galaxy, but whose spectrum shows no evidence for stars. The gas in the cloud is excited by the quasar itself. If a host galaxy is present, it is at least six times fainter than would normally be expected for such a bright quasar. The quasar is interacting dynamically with a neighbouring galaxy, whose gas might be feeding the black hole.

  10. The coevolution of supermassive black holes and galaxies at z [ge] 1: Galaxy morphology, gravitational lensing, and quasar host galaxies

    NASA Astrophysics Data System (ADS)

    Peng, Chien Yi

    Supermassive black holes are ubiquitous in nearby galaxies. The strong correlations between black hole masses and their host galaxy bulges suggest they are intimately connected. To understand their coevolution we study quasars where both quantities can be probed out to high redshifts. To overcome the well known obstacles in studying quasar hosts at z > 1, we study 28 gravitationally lensed host galaxies, located at 1 <= z s <= 4.5, which are stretched out into arcs and Einstein rings. Applying two new algorithms, GALFIT and LENSFIT, to images obtained in the HST NICMOS F160W filter, we clearly resolve the host galaxies. Many have evidences of multiple components, interaction, offset galaxy components, or bulges and disks. The host galaxies at z > 1 are mostly brighter than [Special characters omitted.] galaxies today, but would become fainter than [Special characters omitted.] today after accounting for passive evolution. Furthermore, they have modest sizes ( R e < 6 kpc), and the profiles of the hosts are roughly equally split between bulge dominated and disk dominated. Due to these evidences, the quasar hosts may not be fully evolved early-type galaxies undergoing passive evolution if they evolve into [Special characters omitted.] galaxies today. Moreover, comparing the hosts of radio-loud quasars and radio-quiet quasars, there is not a significant difference in their luminosities. Finally, we study the bulge luminosities ( L bulge ) and black hole masses ( [Special characters omitted.] ) at z [approximate] 1 and z [approximate] 2, finding that the hosts at z > 2 already lie near the same L bulge vs. [Special characters omitted.] relationship as for z = 0 normal galaxies . Accounting for an early-type galaxy evolution, they would fade below the relationship at present day. Therefore, the hosts at z [approximate] 2 must undergo a stellar mass buildup by a factor of 3-5, if they evolve into early-type galaxies. This implies their [Special characters omitted

  11. Herschel-ATLAS: the link between accretion luminosity and star formation in quasar host galaxies

    NASA Astrophysics Data System (ADS)

    Bonfield, D. G.; Jarvis, M. J.; Hardcastle, M. J.; Cooray, A.; Hatziminaoglou, E.; Ivison, R. J.; Page, M. J.; Stevens, J. A.; de Zotti, G.; Auld, R.; Baes, M.; Buttiglione, S.; Cava, A.; Dariush, A.; Dunlop, J. S.; Dunne, L.; Dye, S.; Eales, S.; Fritz, J.; Hopwood, R.; Ibar, E.; Maddox, S. J.; Michałowski, M. J.; Pascale, E.; Pohlen, M.; Rigby, E. E.; Rodighiero, G.; Serjeant, S.; Smith, D. J. B.; Temi, P.; van der Werf, P.

    2011-09-01

    We use the science demonstration field data of the Herschel Astrophysical Terahertz Large Area Survey to study how star formation, traced by the far-infrared Herschel data, is related to both the accretion luminosity and redshift of quasars selected from the Sloan Digital Sky Survey (SDSS) and the 2dF-SDSS luminous red galaxy (LRG) and Quasar Spectroscopic Catalogue survey. By developing a maximum-likelihood estimator to investigate the presence of correlations between the far-infrared and optical luminosities, we find evidence that the star formation in quasar hosts is correlated with both redshift and quasar accretion luminosity. Assuming a relationship of the form LIR∝LθQSO(1 +z)ζ, we find θ= 0.22 ± 0.08 and ζ= 1.6 ± 0.4, although there is substantial additional uncertainty in ζ of the order of ±1, due to uncertainties in the host galaxy dust temperature. We find evidence for a large intrinsic dispersion in the redshift dependence, but no evidence for intrinsic dispersion in the correlation between LQSO and LIR, suggesting that the latter may be due to a direct physical connection between star formation and black hole accretion. This is consistent with the idea that both the quasar activity and star formation are dependent on the same reservoir of cold gas, so that they are both affected by the influx of cold gas during mergers or heating of gas via feedback processes. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  12. Galaxies of all Shapes Host Black Holes

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This artist's concept illustrates the two types of spiral galaxies that populate our universe: those with plump middles, or central bulges (upper left), and those lacking the bulge (foreground).

    New observations from NASA's Spitzer Space Telescope provide strong evidence that the slender, bulgeless galaxies can, like their chubbier counterparts, harbor supermassive black holes at their cores. Previously, astronomers thought that a galaxy without a bulge could not have a supermassive black hole. In this illustration, jets shooting away from the black holes are depicted as thin streams.

    The findings are reshaping theories of galaxy formation, suggesting that a galaxy's 'waistline' does not determine whether it will be home to a big black hole.

  13. Deficiency of ''Thin'' Stellar Bars in Seyfert Host Galaxies

    NASA Technical Reports Server (NTRS)

    Shlosman, Isaac; Peletier, Reynier F.; Knapen, Johan

    1999-01-01

    Using all available major samples of Seyfert galaxies and their corresponding control samples of closely matched non-active galaxies, we find that the bar ellipticities (or axial ratios) in Seyfert galaxies are systematically different from those in non-active galaxies. Overall, there is a deficiency of bars with large ellipticities (i.e., 'fat' or 'weak' bars) in Seyferts, compared to non-active galaxies. Accompanied with a large dispersion due to small number statistics, this effect is strictly speaking at the 2 sigma level. To obtain this result, the active galaxy samples of near-infrared surface photometry were matched to those of normal galaxies in type, host galaxy ellipticity, absolute magnitude, and, to some extent, in redshift. We discuss possible theoretical explanations of this phenomenon within the framework of galactic evolution, and, in particular, of radial gas redistribution in barred galaxies. Our conclusions provide further evidence that Seyfert hosts differ systematically from their non-active counterparts on scales of a few kpc.

  14. HOST GALAXIES OF X-SHAPED RADIO SOURCES

    SciTech Connect

    Springmann, A.; Cheung, C.

    2007-01-01

    Most radiation from galaxies containing active galactic nuclei (AGNs) is emitted not by the stars composing the galaxy, but from an active source at the galactic center, most likely a supermassive black hole. Of particular interest are radio galaxies, active galaxies that emit much of their radiation at radio wavelengths. Within each radio galaxy, an AGN powers a pair of collimated jets of relativistic particles, forming a pair of giant lobes at the end of the jets and thus giving a characteristic double-lobed appearance. A particular class of radio galaxies has an “X”-or winged-shaped morphology: in these, two pairs of lobes appear to originate from the galactic center, producing a distinctive X-shape. Two main mechanisms have been proposed to explain the X-shape morphology: one being a realignment of the black hole within the AGN and the second positing that the radio jets are expanding into an asymmetric medium, causing backflow and producing secondary wings. By analyzing radio host galaxy shapes, the distribution of the stellar mass is compared to the differing model expectations regarding the distribution of the surrounding gas and stellar material about the AGN. Results show elliptical host galaxies with an orthogonal offset between the semi-major axis of the host galaxy and the secondary radio wings, which lends support to the hydrodynamical model. However, results also show circular host galaxies with radio wings, making the realignment scenario a more likely model to describe the formation of these X-shaped radio sources.

  15. Identifying the host galaxy of the short GRB 100628A

    NASA Astrophysics Data System (ADS)

    Nicuesa Guelbenzu, A.; Klose, S.; Palazzi, E.; Greiner, J.; Michałowski, M. J.; Kann, D. A.; Hunt, L. K.; Malesani, D.; Rossi, A.; Savaglio, S.; Schulze, S.; Xu, D.; Afonso, P. M. J.; Elliott, J.; Ferrero, P.; Filgas, R.; Hartmann, D. H.; Krühler, T.; Knust, F.; Masetti, N.; Olivares E., F.; Rau, A.; Schady, P.; Schmidl, S.; Tanga, M.; Updike, A. C.; Varela, K.

    2015-11-01

    We report on the results of a comprehensive observing campaign to reveal the host galaxy of the short GRB 100628A. This burst was followed by a faint X-ray afterglow but no optical counterpart was discovered. However, inside the X-ray error circle a potential host galaxy at a redshift of z = 0.102 was soon reported in the literature. If this system is the host, then GRB 100628A was the cosmologically most nearby unambiguous short burst with a measured redshift so far. We used the multi-colour imager GROND at the ESO/La Silla MPG 2.2 m telescope, ESO/VLT spectroscopy, and deep Australia Telescope Compact Array (ATCA) radio-continuum observations together with publicly available Gemini imaging data to study the putative host and the galaxies in the field of GRB 100628A. We confirm that inside the X-ray error circle the most probable host-galaxy candidate is the morphologically disturbed, interacting galaxy system at z = 0.102. The interacting galaxies are connected by a several kpc long tidal stream, which our VLT/FORS2 spectroscopy reveals strong emission lines of [O ii], [O iii], Hα and Hβ, characteristic for the class of extreme emission-line galaxies and indicative of ongoing star formation. The latter leaves open the possibility that the GRB progenitor was a member of a young stellar population. However, we indentify a second host-galaxy candidate slightly outside the X-ray error circle. It is a radio-bright, luminous elliptical galaxy at a redshift z = 0.311. With a K-band luminosity of 2 × 1011L⊙ this galaxy resembles the probable giant elliptical host of the first well-localized short burst, GRB 050509B. If this is the host, then the progenitor of GRB 100628A was a member of an old stellar population. Based on observations collected at the Very Large Telescope of the European Southern Observatory, Paranal, Chile (ESO programme 087.D-0503 and 290.D-5194; PI: A. Nicuesa Guelbenzu; 090.A-0825; PI: D. Malesani), GROND (PI: J. Greiner), and ATCA (Program C

  16. CORE-COLLAPSE SUPERNOVAE AND HOST GALAXY STELLAR POPULATIONS

    SciTech Connect

    Kelly, Patrick L.; Kirshner, Robert P.

    2012-11-10

    We have used images and spectra of the Sloan Digital Sky Survey to examine the host galaxies of 519 nearby supernovae (SN). The colors at the sites of the explosions, as well as chemical abundances, and specific star formation rates (SFRs) of the host galaxies provide circumstantial evidence on the origin of each SN type. We examine separately SN II, SN IIn, SN IIb, SN Ib, SN Ic, and SN Ic with broad lines (SN Ic-BL). For host galaxies that have multiple spectroscopic fibers, we select the fiber with host radial offset most similar to that of the SN. Type Ic SN explode at small host offsets, and their hosts have exceptionally strongly star-forming, metal-rich, and dusty stellar populations near their centers. The SN Ic-BL and SN IIb explode in exceptionally blue locations, and, in our sample, we find that the host spectra for SN Ic-BL show lower average oxygen abundances than those for SN Ic. SN IIb host fiber spectra are also more metal-poor than those for SN Ib, although a significant difference exists for only one of two strong-line diagnostics. SN Ic-BL host galaxy emission lines show strong central specific SFRs. In contrast, we find no strong evidence for different environments for SN IIn compared to the sites of SN II. Because our SN sample is constructed from a variety of sources, there is always a risk that sampling methods can produce misleading results. We have separated the SN discovered by targeted surveys from those discovered by galaxy-impartial searches to examine these questions and show that our results do not depend sensitively on the discovery technique.

  17. The host galaxies of AGN with powerful relativistic jets

    NASA Astrophysics Data System (ADS)

    Olguín-Iglesias, A.; León-Tavares, J.; Kotilainen, J. K.; Chavushyan, V.; Tornikoski, M.; Valtaoja, E.; Añorve, C.; Valdés, J.; Carrasco, L.

    2016-08-01

    We present deep Near-infrared (NIR) images of a sample of 19 intermediate-redshift (0.310^27 WHz^-1), previously classified as flat-spectrum radio quasars. We also compile host galaxy and nuclear magnitudes for blazars from literature. The combined sample (this work and compilation) contains 100 radio-loud AGN with host galaxy detections and a broad range of radio luminosities L1.4GHz = 10^23.7 - 10^28.3WHz^-1, allowing us to divide our sample into high-excitation (quasar-mode; HERGs) and low-excitation (radio-mode; LERGs) radio galaxies. The host galaxies of our sample are bright and seem to follow the Kormendy relation. Nuclear emission (dominated by non-thermal mechanisms) and host-galaxy magnitudes show a slightly negative weak trend for LERGs. On the other hand, the m_bulge -m_nuc relation is statistically significant for HERGs. Although it may be affected by selection effects, this correlation suggests a close coupling between the relativistic jets and their host galaxy. Our findings are consistent with the excitation state (LERG/HERG) scenario. In this view, LERGs emit the bulk of their energy in the form of radio jets, producing a strong feedback mechanism, and HERGs are affected by galaxy mergers and interactions, which provide a common supply of cold gas to feed both nuclear activity and star formation episodes.

  18. Long-Wavelength Demographics of GRB Host Galaxies

    NASA Astrophysics Data System (ADS)

    Perley, Daniel A.

    2017-01-01

    We present new VLA observations of 32 Swift and pre-Swift GRB host galaxies, supplemented by new ALMA and Herschel observations. Although our observations are quite deep, we securely detect only a few targets in the sample. Indeed, we rule out several claimed detections of ULIRG-like host galaxies in the previous literature, including every pre-Swift ULIRG-like host: these now appear to have been due to residual afterglow contamination or source confusion. Our results indicate that only a small minority of GRBs (~10%) occur in ULIRG-like galaxies and that intense star-formation does little to directly facilitate GRB production. This suggests in turn that dynamical interactions or ultra-massive stellar progenitors are not likely to be critical ingredients in GRB formation. Every GRB securely associated with a ULIRG is observed to significantly dust-obscured, consistent with the large dust optical depths and covering frations thought to be characteristic of these systems.

  19. The SEDs and Host Galaxies of the Dustiest GRB Afterglows

    NASA Technical Reports Server (NTRS)

    Kruhler, T.; Greiner, J.; Schady, P.; Savaglio, S.; Afonso, P. M. J.; Clemens, C.; Elliott, J.; Filgas, R.; Gruber, D.; Kann, D. A.; Klose, S.; Kupcu-Yoldas, A.; McBreen, S.; Olivares, E.; Pierini, D.; Rau, A.; Rossi, A.; Nardini, M.; Nicuesa Guelbenzu, A.; Sudilovsky, V.; Updike, A. C.

    2011-01-01

    The afterglows and host galaxies of long gamma-ray bursts (GRBs) offer unique opportunities to study star-forming galaxies in the high-z Universe, Until recently, however. the information inferred from GRB follow-up observations was mostly limited to optically bright afterglows. biasing all demographic studies against sight-lines that contain large amounts of dust. Aims. Here we present afterglow and host observations for a sample of bursts that are exemplary of previously missed ones because of high visual extinction (A(sub v) (Sup GRB) approx > 1 mag) along the sight-line. This facilitates an investigation of the properties, geometry and location of the absorbing dust of these poorly-explored host galaxies. and a comparison to hosts from optically-selected samples. Methods. This work is based on GROND optical/NIR and Swift/XRT X-ray observations of the afterglows, and multi-color imaging for eight GRB hosts. The afterglow and galaxy spectral energy distributions yield detailed insight into physical properties such as the dust and metal content along the GRB sight-line as well as galaxy-integrated characteristics like the host's stellar mass, luminosity. color-excess and star-formation rate. Results. For the eight afterglows considered in this study we report for the first time the redshift of GRBs 081109 (z = 0.97S7 +/- 0.0005). and the visual extinction towards GRBs 0801109 (A(sub v) (Sup GRB) = 3.4(sup +0.4) (sub -0.3) mag) and l00621A (A(sub v) (Sup GRB) = 3.8 +/- 0.2 mag), which are among the largest ever derived for GRB afterglows. Combined with non-extinguished GRBs. there is a strong anti-correlation between the afterglow's metals-to-dust ratio and visual extinction. The hosts of the dustiest afterglows are diverse in their properties, but on average redder(((R - K)(sub AB)) approximates 1.6 mag), more luminous ( approximates 0.9 L (sup *)) and massive ((log M(sup *) [M(solar]) approximates 9.8) than the hosts of optically-bright events. We hence probe

  20. THE EXTREMELY RED HOST GALAXY OF GRB 080207

    SciTech Connect

    Hunt, Leslie; Cresci, Giovanni; Palazzi, Eliana; Rossi, Andrea; Klose, Sylvio; Savaglio, Sandra; Michalowski, Michal; Pian, Elena

    2011-08-01

    We present optical, near-infrared, and Spitzer IRAC and MIPS observations of the host galaxy of the dark Swift gamma-ray burst GRB 080207. The host is faint, with extremely red optical-infrared colors (R - K = 6.3, 24 {mu}m/R-band flux {approx}1000) making it an extremely red object (ERO) and a dust-obscured galaxy (DOG). The spectral energy distribution (SED) shows the clear signature of the 1.6 {mu}m photometric 'bump', typical of evolved stellar populations. We use this bump to establish the photometric redshift z{sub phot} as 2.2{sup +0.2}{sub -0.3}, using a vast library of SED templates, including M 82. The star formation rate (SFR) inferred from the SED fitting is {approx}119 M{sub sun} yr{sup -1}, the stellar mass 3 x 10{sup 11} M{sub sun}, and A{sub V} extinction from 1 to 2 mag. The ERO and DOG nature of the host galaxy of the dark GRB 080207 may be emblematic of a distinct class of dark GRB hosts, with high SFRs, evolved and metal-rich stellar populations, and significant dust extinction within the host galaxy.

  1. The SEDs and host galaxies of the dustiest GRB afterglows

    NASA Astrophysics Data System (ADS)

    Krühler, T.; Greiner, J.; Schady, P.; Savaglio, S.; Afonso, P. M. J.; Clemens, C.; Elliott, J.; Filgas, R.; Gruber, D.; Kann, D. A.; Klose, S.; Küpcü-Yoldaş, A.; McBreen, S.; Olivares, F.; Pierini, D.; Rau, A.; Rossi, A.; Nardini, M.; Nicuesa Guelbenzu, A.; Sudilovsky, V.; Updike, A. C.

    2011-10-01

    Context. The afterglows and host galaxies of long gamma-ray bursts (GRBs) offer unique opportunities to study star-forming galaxies in the high-z Universe. Until recently, however, the information inferred from GRB follow-up observations was mostly limited to optically bright afterglows, biasing all demographic studies against sight-lines that contain large amounts of dust. Aims: Here we present afterglow and host observations for a sample of bursts that are exemplary of previously missed ones because of high visual extinction (AVGRB ≳ 1 mag) along the sight-line. This facilitates an investigation of the properties, geometry, and location of the absorbing dust of these poorly-explored host galaxies, and a comparison to hosts from optically-selected samples. Methods: This work is based on GROND optical/NIR and Swift/XRT X-ray observations of the afterglows, and multi-color imaging for eight GRB hosts. The afterglow and galaxy spectral energy distributions yield detailed insight into physical properties such as the dust and metal content along the GRB sight-line and galaxy-integrated characteristics such as the host's stellar mass, luminosity, color-excess, and star-formation rate. Results: For the eight afterglows considered in this study, we report for the first time the redshift of GRB 081109 (z = 0.9787 ± 0.0005), and the visual extinction towards GRBs 081109 (AVGRB = 3.4-0.3+0.4 mag) and 100621A (AVGRB = 3.8±0.2 mag), which are among the largest ever derived for GRB afterglows. Combined with non-extinguished GRBs, there is a strong anti-correlation between the afterglow's metal-to-dust ratio and visual extinction. The hosts of the dustiest afterglows are diverse in their properties, but on average redder (⟨ (R - K)AB ⟩ ~ 1.6 mag), more luminous (⟨ L ⟩ ~ 0.9 L∗), and massive (⟨ log M∗ [M⊙] ⟩ ~ 9.8) than the hosts of optically-bright events. Hence, we probe a different galaxy population, suggesting that previous host samples miss most of the

  2. Jet Feedback on the Hosts of Radio Galaxies

    NASA Astrophysics Data System (ADS)

    Lanz, L.; Ogle, P. M.; Alatalo, K.; Appleton, P. N.

    2016-06-01

    Feedback due to active galactic nuclei is one of the key components of the current paradigm of galaxy evolution; however our understanding of the process remains incomplete. Radio galaxies with strong rotational H_2 emission provide an interesting window into the effect of radio jet feedback on their host galaxies, since the large masses of warm (>100 K) H_2 cannot solely be heated by star formation, instead requiring jet-driven ISM turbulence to power the molecular emission. I will discuss the insights multiwavelength (X-ray to submm) observations of 22 H_2 luminous radio galaxies yield on the process of jet feedback in these galaxies and the impact on star formation activity. Specifically, I find that the diffuse X-ray and warm H_2 emission are consistent with both being powered by dissipation of the jet's mechanical energy into the interstellar medium (ISM) and that the resulting turbulence injected into the ISM by this process results in the suppression of star formation activity by a factor of 3--6. The hosts of these galaxies show a wide range of star formation activity and optical and IR colors, indicating a diversity of evolutionary states in which this process may be active.

  3. Coevolution (Or Not) of Supermassive Black Holes and Host Galaxies

    NASA Astrophysics Data System (ADS)

    Kormendy, John; Ho, Luis C.

    2013-08-01

    Supermassive black holes (BHs) have been found in 85 galaxies by dynamical modeling of spatially resolved kinematics. The Hubble Space Telescope revolutionized BH research by advancing the subject from its proof-of-concept phase into quantitative studies of BH demographics. Most influential was the discovery of a tight correlation between BH mass [Formula: see text] and the velocity dispersion σ of the bulge component of the host galaxy. Together with similar correlations with bulge luminosity and mass, this led to the widespread belief that BHs and bulges coevolve by regulating each other's growth. Conclusions based on one set of correlations from [Formula: see text] in brightest cluster ellipticals to [Formula: see text] in the smallest galaxies dominated BH work for more than a decade. New results are now replacing this simple story with a richer and more plausible picture in which BHs correlate differently with different galaxy components. A reasonable aim is to use this progress to refine our understanding of BH-galaxy coevolution. BHs with masses of 105-106M⊙ are found in many bulgeless galaxies. Therefore, classical (elliptical-galaxy-like) bulges are not necessary for BH formation. On the other hand, although they live in galaxy disks, BHs do not correlate with galaxy disks. Also, any [Formula: see text] correlations with the properties of disk-grown pseudobulges and dark matter halos are weak enough to imply no close coevolution. The above and other correlations of host-galaxy parameters with each other and with [Formula: see text] suggest that there are four regimes of BH feedback. (1) Local, secular, episodic, and stochastic feeding of small BHs in largely bulgeless galaxies involves too little energy to result in coevolution. (2) Global feeding in major, wet galaxy mergers rapidly grows giant BHs in short-duration, quasar-like events whose energy feedback does affect galaxy evolution. The resulting hosts are classical bulges and coreless

  4. Disentangling AGN-Host Galaxy Interactions with Chandra

    NASA Astrophysics Data System (ADS)

    Wang, Junfeng

    2014-11-01

    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 AGN-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 AGN systems and signs of past AGN outburst activities.

  5. Simple stellar population modelling of low S/N galaxy spectra and quasar host galaxy applications

    NASA Astrophysics Data System (ADS)

    Mosby, G.; Tremonti, C. A.; Hooper, E. J.; Wolf, M. J.; Sheinis, A. I.; Richards, J. W.

    2015-02-01

    To study the effect of supermassive black holes (SMBHs) on their host galaxies it is important to study the hosts when the SMBH is near its peak activity. A method to investigate the host galaxies of high luminosity quasars is to obtain optical spectra at positions offset from the nucleus where the relative contribution of the quasar and host is comparable. However, at these extended radii the galaxy surface brightness is often low (20-22 mag arcsec-2) and the resulting spectrum might have such low signal-to-noise ratio (S/N) that it hinders analysis with standard stellar population modelling techniques. To address this problem, we have developed a method that can recover galaxy star formation histories (SFHs) from rest-frame optical spectra with S/N ˜ 5 Å-1. This method uses the statistical technique diffusion k-means to tailor the stellar population modelling basis set. Our diffusion k-means minimal basis set, composed of four broad age bins, is successful in recovering a range of galaxy SFHs. Additionally, using an analytic prescription for seeing conditions, we are able to simultaneously model scattered quasar light and the SFH of quasar host galaxies (QHGs). We use synthetic data to compare results of our novel method with previous techniques. We also present the modelling results on a previously published QHG and show that galaxy properties recovered from a diffusion k-means basis set are less sensitive to noise added to this QHG spectrum. Our new method has a clear advantage in recovering information from QHGs and could also be applied to the analysis of other low S/N galaxy spectra such as those typically obtained for high redshift objects or integral field spectroscopic surveys.

  6. Identifying the host galaxy of gravitational wave signals

    SciTech Connect

    Nuttall, Laura K.; Sutton, Patrick J.

    2010-11-15

    One of the goals of the current LIGO-GEO-Virgo science run is to identify transient gravitational wave (GW) signals in near real time to allow follow-up electromagnetic (EM) observations. An EM counterpart could increase the confidence of the GW detection and provide insight into the nature of the source. Current GW-EM campaigns target potential host galaxies based on overlap with the GW sky error box. We propose a new statistic to identify the most likely host galaxy, ranking galaxies based on their position, distance, and luminosity. We test our statistic with Monte Carlo simulations of GWs produced by coalescing binaries of neutron stars and black holes, one of the most promising sources for ground-based GW detectors. Considering signals accessible to current detectors, we find that when imaging a single galaxy, our statistic correctly identifies the true host {approx}20% to {approx}50% of the time, depending on the masses of the binary components. With five narrow-field images the probability of imaging the true host increases from {approx}50% to {approx}80%. When collectively imaging groups of galaxies using large field-of-view telescopes, the probability improves from {approx}30% to {approx}60% for a single image and from {approx}70% to {approx}90% for five images. For the advanced generation of detectors (circa 2015+), and considering binaries within 100 Mpc (the reach of the galaxy catalogue used), the probability is {approx}40% for one narrow-field image, {approx}75% for five narrow-field images, {approx}65% for one wide-field image, and {approx}95% for five wide-field images, irrespective of binary type.

  7. Host Galaxies of X-Shaped Radio Sources

    SciTech Connect

    Springmann, Alessondra; /Wellesley Coll. /SLAC

    2006-09-27

    The majority of radiation from galaxies containing active galactic nuclei (AGNs) is emitted not by the stars composing the galaxy, but from an active source at the galactic center, most likely a supermassive black hole. Of particular interest are radio galaxies, the active galaxies emitting much of their radiation at radio wavelengths. Within each radio galaxy, an AGN powers a pair of collimated jets of relativistic particles, forming a pair of giant lobes at the end of the jets and thus giving a characteristic double-lobed appearance. A particular class of radio galaxies have an ''X''-shaped morphology: in these, two pairs of lobes appear to originate from the galactic center, producing a distinctive X-shape. Two main mechanisms have been proposed to explain the X-shape morphology: one being through the merger of a binary supermassive black hole system and the second being that the radio jets are expanding into an asymmetric medium. By analyzing radio host galaxy shapes, we probe the distribution of the stellar mass to compare the differing model expectations regarding the distribution of the surrounding gas and stellar material about the AGN.

  8. Quasar Metallicities and Host Galaxy Evolution

    NASA Astrophysics Data System (ADS)

    Leah, Simon E.; Hamann, F. W.

    2006-12-01

    From studies of galaxies in the local Universe we find the masses of the galactic spheroidal component corresponds with the mass of the central supermassive black hole (SMBH). This relation is known as the M(gal) M(BH) relation, and suggests a close relationship between the formation of the galaxy and the black hole. We study the metallicities near quasars at high redshift to observe this formation process in action. Associated absorption lines (AALs) provide us with a unique tool for this study, because these lines have a high probability of forming close to the quasar. Most of the work so far, using the emission lines, suggests that quasar environments are typically metal rich, with gas-phase metallicities near solar or higher at all observed redshifts. However, other independant abundance checks, such as AALs, are essential in order to confirm these results. We use very high resolution echelle spectra from VLT-UVES for 8 high redshift (z of 2 to z of 4.6) quasars, selected to contain candidate intrinsic absorbers, and ecompassing a typical rest-frame spectral range from approximatly 900 Angstroms to 2500 Angstroms, designed to include at least Lyman alpha and C IV spectral features. We perform one of the first analyses of absorption line metallicities in high redshift quasars and present lower limits on column densities, as well as estimates for the absorber locations relative to the quasar. We place rough estimates on the abundances where possible. We find covering fractions which vary with velocity, and a significant fraction of absorption lines which exhibit variability, indicating their intrinsic nature. Saturated lines inhibit concrete abundance analysis, but present excellent opportunities for future research proposals.

  9. Quasar Metallicities and Host Galaxy Evolution

    NASA Astrophysics Data System (ADS)

    Simon, Leah; Hamann, F.

    2007-12-01

    From studies of galaxies in the local Universe we find the masses of the galactic spheroidal component corresponds with the mass of the central supermassive black hole (SMBH). This relation is known as the M(gal) - M(BH) relation, and suggests a close relationship between the formation of the galaxy and the black hole. We study the metallicities near quasars at high redshift to observe this formation process in action. Associated absorption lines (AALs) provide us with a unique tool for this study, because these lines have a high probability of forming close to the quasar. Most of the work so far, using the emission lines, suggests that quasar environments are typically metal rich, with gas-phase metallicities near solar or higher at all observed redshifts. However, other independent abundance checks, such as AALs, are essential in order to confirm these results. We use very high resolution echelle spectra from VLT-UVES, Keck-HIRES and Magellan-MIKE for 18 high redshift (z of 2 to z of 4.6) quasars, selected to contain candidate intrinsic absorbers, and encompassing a typical rest-frame spectral range from approximately 900 Angstroms to 2500 Angstroms, designed to include at least Lyman alpha and C IV spectral features. We perform one of the first analyses of absorption line metallicities in high redshift quasars and present column densities, as well as estimates for the absorber locations relative to the quasar. We place solid limits on the C/H abundances, and find a wide range of values, from one hundredth solar to several times solar. We find covering fractions which vary with velocity, indicating the intrinsic nature of the absorbing gas. Saturated lines inhibit concrete abundance analysis in some systems, but are still useful for placing limits based on Gaussian fits to the lines.

  10. EXTREME HOST GALAXY GROWTH IN POWERFUL EARLY-EPOCH RADIO GALAXIES

    SciTech Connect

    Barthel, Peter; Haas, Martin; Leipski, Christian; Wilkes, Belinda

    2012-10-01

    During the first half of the universe's life, a heyday of star formation must have occurred because many massive galaxies are in place after that epoch in cosmic history. Our observations with the revolutionary Herschel Space Observatory reveal vigorous optically obscured star formation in the ultra-massive hosts of many powerful high-redshift 3C quasars and radio galaxies. This symbiotic occurrence of star formation and black hole driven activity is in marked contrast to recent results dealing with Herschel observations of X-ray-selected active galaxies. Three archetypal radio galaxies at redshifts 1.132, 1.575, and 2.474 are presented here, with inferred star formation rates of hundreds of solar masses per year. A series of spectacular coeval active galactic nucleus/starburst events may have formed these ultra-massive galaxies and their massive central black holes during their relatively short lifetimes.

  11. The Host Galaxies of Micro-Jansky Radio Sources

    NASA Astrophysics Data System (ADS)

    Luchsinger, K. M.; Lacy, M.; Jones, K. M.; Mauduit, J. C.; Pforr, J.; Surace, J. A.; Vaccari, M.; Farrah, D.; Gonzales-Solares, E.; Jarvis, M. J.; Maraston, C.; Marchetti, L.; Oliver, S.; Afonso, J.; Cappozi, D.; Sajina, A.

    2015-09-01

    We combine a deep 0.5 deg2, 1.4 GHz deep radio survey in the Lockman Hole with infrared and optical data in the same field, including the Spitzer Extragalactic Representative Volume Survey (SERVS) and UKIDSS near-infrared surveys, to make the largest study to date of the host galaxies of radio sources with typical radio flux densities ˜ 50 μJy. 87% (1274/1467) of radio sources have identifications in SERVS to {AB}≈ 23.1 at 3.6 or 4.5μm, and 9% are blended with bright objects (mostly stars), leaving only 4% (59 objects), which are too faint to confidently identify in the near-infrared. We are able to estimate photometric redshifts for 68% of the radio sources. We use mid-infrared diagnostics to show that the source population consists of a mixture of star-forming galaxies, rapidly accreting (cold mode) active galactic nuclei (AGNs) and low accretion rate (hot mode) AGNs, with neither AGNs nor star-forming galaxies clearly dominating. We see the breakdown in the K-z relation in faint radio source samples, and show that it is due to radio source populations becoming dominated by sources with radio luminosities ˜ {10}23 {{WHz}}-1. At these luminosities, both the star-forming galaxies and the cold mode AGNs have hosts with stellar luminosities of about a factor of two lower than those of hot mode AGNs, which continue to reside in only the most massive hosts. We show that out to at least z˜ 2, galaxies with stellar masses \\gt {10}11.5 {M}⊙ have radio-loud fractions up to ˜30%. This is consistent with there being a sufficient number of radio sources for radio-mode feedback to play a role in galaxy evolution.

  12. HST Observations of the Host Galaxy of GRB970508

    NASA Astrophysics Data System (ADS)

    Fruchter, A.; Pian, E.

    1998-08-01

    The field of GRB970508 was imaged by HST with the STIS CCD in open filter mode (50CCD) on 1998 August 5.78-6.03 for a total exposure time of 11,568 seconds. An extended object, which we believe to be the host galaxy of GRB970508, was detected at the astrometric position of the optical transient of GRB970508. The galaxy has high signal-to-noise in our data and is clearly resolved, with a major axis of approximately 0."5 .

  13. OPTICAL PROPERTIES OF HOST GALAXIES OF EXTRAGALACTIC NUCLEAR WATER MASERS

    SciTech Connect

    Zhu Guangtun; Zaw, Ingyin; Blanton, Michael R.; Greenhill, Lincoln J.

    2011-12-01

    We study the optical properties of the host galaxies of nuclear 22 GHz ({lambda} = 1.35 cm) water masers. To do so, we cross-match the galaxy sample surveyed for water maser emission (123 detections and 3806 non-detections) with the Sloan Digital Sky Survey (SDSS) low-redshift galaxy sample (z < 0.05). Out of 1636 galaxies with SDSS photometry, we identify 48 detections; out of the 1063 galaxies that also have SDSS spectroscopy, we identify 33 detections. We find that maser detection rate is higher at higher optical luminosity (M{sub B} ), larger velocity dispersion ({sigma}), and higher [O III] {lambda}5007 luminosity, with [O III] {lambda}5007 being the dominant factor. These detection rates are essentially the result of the correlations of isotropic maser luminosity with all three of these variables. These correlations are natural if maser strength increases with central black hole mass and the level of active galactic nucleus (AGN) activity. We also find that the detection rate is higher in galaxies with higher extinction. Based on these results, we propose that maser surveys seeking to efficiently find masers should rank AGN targets by extinction-corrected [O III] {lambda}5007 flux when available. This prioritization would improve maser detection efficiency, from an overall {approx}3% without pre-selection to {approx}16% for the strongest intrinsic [O III] {lambda}5007 emitters, by a factor of {approx}5.

  14. The Role of Host Galaxy for the Environmental Dependence of Active Nuclei in Local Galaxies

    NASA Astrophysics Data System (ADS)

    Davies, Richard I.; Hicks, E. K. S.; Erwin, P.; Burtscher, L.; Contursi, A.; Genzel, R.; Janssen, A.; Koss, M.; Lin, M.-Y.; Lutz, D.; Maciejewski, W.; Müller-Sánchez, F.; Orban de Xivry, G.; Ricci, C.; Riffel, R.; Riffel, R. A.; Rosario, D.; Schartmann, M.; Schnorr-Müller, A.; Shimizu, T.; Sternberg, A.; Sturm, E.; Storchi-Bergmann, T.; Tacconi, L.; Veilleux, S.

    2017-01-01

    We discuss the environment of local hard X-ray selected active galaxies, with reference to two independent group catalogues. We find that the fraction of these AGN in S0 host galaxies decreases strongly as a function of galaxy group size (halo mass) - which contrasts with the increasing fraction of galaxies of S0 type in denser environments. However, there is no evidence for an environmental dependence of AGN in spiral galaxies. Because most AGN are found in spiral galaxies, this dilutes the signature of environmental dependence for the population as a whole. We argue that the differing results for AGN in disk-dominated and bulge-dominated galaxies is related to the source of the gas fuelling the AGN, and so may also impact the luminosity function, duty cycle, and obscuration. We find that there is a significant difference in the luminosity function for AGN in spiral and S0 galaxies, and tentative evidence for some difference in the fraction of obscured AGN.

  15. WEAVE-QSO: A Massive Intergalactic Medium Survey for the William Herschel Telescope

    NASA Astrophysics Data System (ADS)

    Pieri, M. M.; Bonoli, S.; Chaves-Montero, J.; Pâris, I.; Fumagalli, M.; Bolton, J. S.; Viel, M.; Noterdaeme, P.; Miralda-Escudé, J.; Busca, N. G.; Rahmani, H.; Peroux, C.; Font-Ribera, A.; Trager, S. C.

    2016-12-01

    In these proceedings we describe the WEAVE-QSO survey, which will observe around 400,000 high redshift quasars starting in 2018. This survey is part of a broader WEAVE survey to be conducted at the 4.2m William Herschel Telescope. We will focus on chiefly on the science goals, but will also briefly summarise the target selection methods anticipated and the expected survey plan. Understanding the apparent acceleration in the expansion of the Universe is one of the key scientific challenges of our time. Many experiments have been proposed to study this expansion, using a variety of techniques. Here we describe a survey that can measure this acceleration and therefore help elucidate the nature of dark energy: a survey of the Lyα forest (and quasar absorption in general) in spectra towards z>2 quasars (QSOs). Further constraints on neutrino masses and warm dark matter are also anticipated. The same data will also shed light on galaxy formation via study of the properties of inflowing/outflowing gas associated with nearby galaxies and in a cosmic web context. Gas properties are sensitive to density, temperature, UV radiation, metallicity and abundance pattern, and so constraint galaxy formation in a variety of ways. WEAVE-QSO will study absorbers with a dynamic range spanning more than 8 orders of magnitude in column density, their thermal broadening, and a host of elements and ionization species. A core principal of the WEAVE-QSO survey is the targeting of QSOs with near 100% efficiency principally through use of the J-PAS (r < 23.2) and Gaia (r ≲ 20) data.

  16. What are the galaxies that host MIR-selected AGN?

    NASA Astrophysics Data System (ADS)

    Rosario, David

    2016-08-01

    Infra-red selection techniques, sensitive to dust strongly heated by an AGN, 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 AGN to z>2 selected using Spitzer/IRAC based methods in the COSMOS field. Armed with AGN-optimised redshifts and stellar masses, we explore the dust emission from the active nucleus and the host galaxy. We demonstrate that IR-selected AGN tend to be found in low mass host galaxies, when compared to other AGN identification methods. The star-formation rates of obscured and unobscured IR-selected AGN are very similar, implying that large-scale obscuration with co-eval star-bursts are not found in a major proportion of heavily obscured AGN.

  17. Probing the Black Hole-Galaxy Connection with AGN Host Galaxy Morphologies

    NASA Astrophysics Data System (ADS)

    Simmons, Brooke; Urry, C. M.; COSMOS Team

    2006-12-01

    There is increasing evidence that galaxies and supermassive black holes form and evolve together, exerting mutual feedback that governs the galaxy dynamics and the black hole mass. During their growth phase, supermassive black holes are readily visible as Active Galactic Nuclei (AGN). The morphologies of AGN host galaxies offer a powerful, direct probe of the AGN-galaxy connection. We are carrying out morphological analysis of large AGN samples from deep multi-wavelength surveys, comparing the results to well-selected samples of inactive galaxies. To interpret the results properly requires understanding the observational bias introduced by the central point source, which can hide compact features and thus influence the extracted AGN host morphological parameters. Therefore, we performed extensive simulations, involving a variety of galaxy types over a range of redshifts. Here we present results of these simulations and describe preliminary work on deep HST ACS images from the COSMOS field. We gratefully acknowledge support from HST grants AR-10689.01-A and GO-09822.09-A, and Yale University.

  18. Probing the Black Hole-Galaxy Connection with AGN Host Galaxy Morphologies

    NASA Astrophysics Data System (ADS)

    Simmons, Brooke; Urry, C. M.; COSMOS Team

    2007-05-01

    There is increasing evidence that galaxies and supermassive black holes form and evolve together, exerting mutual feedback that governs the galaxy dynamics and the black hole mass. During their growth phase, supermassive black holes are readily visible as Active Galactic Nuclei (AGN). The morphologies of AGN host galaxies offer a powerful, direct probe of the AGN-galaxy connection. We are carrying out morphological analysis of large AGN samples from deep multi-wavelength surveys, comparing the results to well-selected samples of inactive galaxies. To interpret the results properly requires understanding the observational bias introduced by the central point source, which can hide compact features and thus influence the extracted AGN host morphological parameters. Therefore, we performed extensive simulations, involving a variety of galaxy types over a range of redshifts. Here we present results of these simulations and describe preliminary work on deep HST ACS images from the COSMOS field. We gratefully acknowledge support from HST grants AR-10689.01-A and GO-09822.09-A, and Yale University.

  19. REVISITING THE FIRST GALAXIES: THE EFFECTS OF POPULATION III STARS ON THEIR HOST GALAXIES

    SciTech Connect

    Muratov, Alexander L.; Gnedin, Oleg Y.; Zemp, Marcel; Gnedin, Nickolay Y.

    2013-08-01

    We revisit the formation and evolution of the first galaxies using new hydrodynamic cosmological simulations with the adaptive refinement tree code. Our simulations feature a recently developed model for H{sub 2} formation and dissociation, and a star formation recipe that is based on molecular rather than atomic gas. Here, we develop and implement a recipe for the formation of metal-free Population III (Pop III) stars in galaxy-scale simulations that resolve primordial clouds with sufficiently high density. We base our recipe on the results of prior zoom-in simulations that resolved the protostellar collapse in pre-galactic objects. We find the epoch during which Pop III stars dominated the energy and metal budget of the first galaxies to be short-lived. Galaxies that host Pop III stars do not retain dynamical signatures of their thermal and radiative feedback for more than 10{sup 8} years after the lives of the stars end in pair-instability supernovae, even when we consider the maximum reasonable efficiency of the feedback. Though metals ejected by the supernovae can travel well beyond the virial radius of the host galaxy, they typically begin to fall back quickly, and do not enrich a large fraction of the intergalactic medium. Galaxies with a total mass in excess of 3 Multiplication-Sign 10{sup 6} M{sub Sun} re-accrete most of their baryons and transition to metal-enriched Pop II star formation.

  20. GRB 990712 optical decay: indication of bright host galaxy.

    NASA Astrophysics Data System (ADS)

    Hjorth, J.; Courbin, F.; Cuadra, J.; Minniti, D.

    We have obtained a 5-min R-band exposure of the optical afterglow of GRB 990712 (Frontera, GCN #385; Bakos et al., GCN #387) with the ESO 3.5-m NTT on 16.403 July 1999 UT. We detect an unresolved (seeing FWHM = 1.8") object at RA (2000) = 22 31 53.03, Dec (2000) = -73 24 28.3 (with a positional uncertainty of +- 0.6" relative to the USNO-A2.0 system), consistent with the position of the bright decaying source discovered by Bakos et al. (IAUC 7225). We have tied our photometry to the PLANET photometric zeropoint (K. Sahu, personal communication) and find that the object has continued to fade to R = 21.48 +- 0.02 (systematic) +- 0.05 (random). The combined SAAO data (Bakos et al., IAUC 7225) and NTT data indicate that the light curve is leveling off relative to a power law decline. Assuming that the light curve can be modeled as the combined effects of a power law decline of the OT and a constant contribution from the host galaxy we find an OT decay slope of -0.81 (i.e. a rather slow decay) and a bright host galaxy with R = 22.0. Such a bright host galaxy would be consistent with its fairly low redshift (z = 0.43) and would possibly even account for the prominent emission lines seen in the VLT spectrum (Galama et al., GCN #388). We caution however that the hypothesis of a bright host galaxy is based on just a few data points. To test this hypothesis continued monitoring of the system is therefore urged. The NTT image and the R-band light curve are posted at http://www.astro.ku.dk/~jens/grb990712/ .

  1. Locating star-forming regions in quasar host galaxies

    NASA Astrophysics Data System (ADS)

    Young, J. E.; Eracleous, M.; Shemmer, O.; Netzer, H.; Gronwall, C.; Lutz, Dieter; Ciardullo, R.; Sturm, Eckhard

    2014-02-01

    We present a study of the morphology and intensity of star formation in the host galaxies of eight Palomar-Green quasars using observations with the Hubble Space Telescope. Our observations are motivated by recent evidence for a close relationship between black hole growth and the stellar mass evolution in its host galaxy. We use narrow-band [O II]λ3727, Hβ, [O III]λ5007 and Paα images, taken with the Wide Field Planetary Camera 2 and NICMOS instruments, to map the morphology of line-emitting regions, and, after extinction corrections, diagnose the excitation mechanism and infer star-formation rates. Significant challenges in this type of work are the separation of the quasar light from the stellar continuum and the quasar-excited gas from the star-forming regions. To this end, we present a novel technique for image decomposition and subtraction of quasar light. Our primary result is the detection of extended line-emitting regions with sizes ranging from 0.5 to 5 kpc and distributed symmetrically around the nucleus, powered primarily by star formation. We determine star-formation rates of the order of a few tens of M⊙ yr-1. The host galaxies of our target quasars have stellar masses of the order of 1011 M⊙ and specific star-formation rates on a par with those of M82 and luminous infrared galaxies. As such they fall at the upper envelope or just above the star-formation mass sequence in the specific star formation versus stellar mass diagram. We see a clear trend of increasing star-formation rate with quasar luminosity, reinforcing the link between the growth of the stellar mass of the host and the black hole mass found by other authors.

  2. SUPERMASSIVE BLACK HOLES AND THEIR HOST SPHEROIDS. I. DISASSEMBLING GALAXIES

    SciTech Connect

    Savorgnan, G. A. D.; Graham, A. W.

    2016-01-15

    Several recent studies have performed galaxy decompositions to investigate correlations between the black hole mass and various properties of the host spheroid, but they have not converged on the same conclusions. This is because their models for the same galaxy were often significantly different and not consistent with each other in terms of fitted components. Using 3.6 μm Spitzer imagery, which is a superb tracer of the stellar mass (superior to the K band), we have performed state-of-the-art multicomponent decompositions for 66 galaxies with directly measured black hole masses. Our sample is the largest to date and, unlike previous studies, contains a large number (17) of spiral galaxies with low black hole masses. We paid careful attention to the image mosaicking, sky subtraction, and masking of contaminating sources. After a scrupulous inspection of the galaxy photometry (through isophotal analysis and unsharp masking) and—for the first time—2D kinematics, we were able to account for spheroids; large-scale, intermediate-scale, and nuclear disks; bars; rings; spiral arms; halos; extended or unresolved nuclear sources; and partially depleted cores. For each individual galaxy, we compared our best-fit model with previous studies, explained the discrepancies, and identified the optimal decomposition. Moreover, we have independently performed one-dimensional (1D) and two-dimensional (2D) decompositions and concluded that, at least when modeling large, nearby galaxies, 1D techniques have more advantages than 2D techniques. Finally, we developed a prescription to estimate the uncertainties on the 1D best-fit parameters for the 66 spheroids that takes into account systematic errors, unlike popular 2D codes that only consider statistical errors.

  3. Supermassive Black Holes and Their Host Spheroids. I. Disassembling Galaxies

    NASA Astrophysics Data System (ADS)

    Savorgnan, G. A. D.; Graham, A. W.

    2016-01-01

    Several recent studies have performed galaxy decompositions to investigate correlations between the black hole mass and various properties of the host spheroid, but they have not converged on the same conclusions. This is because their models for the same galaxy were often significantly different and not consistent with each other in terms of fitted components. Using 3.6 μm Spitzer imagery, which is a superb tracer of the stellar mass (superior to the K band), we have performed state-of-the-art multicomponent decompositions for 66 galaxies with directly measured black hole masses. Our sample is the largest to date and, unlike previous studies, contains a large number (17) of spiral galaxies with low black hole masses. We paid careful attention to the image mosaicking, sky subtraction, and masking of contaminating sources. After a scrupulous inspection of the galaxy photometry (through isophotal analysis and unsharp masking) and—for the first time—2D kinematics, we were able to account for spheroids large-scale, intermediate-scale, and nuclear disks bars rings spiral arms halos extended or unresolved nuclear sources; and partially depleted cores. For each individual galaxy, we compared our best-fit model with previous studies, explained the discrepancies, and identified the optimal decomposition. Moreover, we have independently performed one-dimensional (1D) and two-dimensional (2D) decompositions and concluded that, at least when modeling large, nearby galaxies, 1D techniques have more advantages than 2D techniques. Finally, we developed a prescription to estimate the uncertainties on the 1D best-fit parameters for the 66 spheroids that takes into account systematic errors, unlike popular 2D codes that only consider statistical errors.

  4. Quasars, their host galaxies and their central black holes

    NASA Astrophysics Data System (ADS)

    Dunlop, J. S.; McLure, R. J.; Kukula, M. J.; Baum, S. A.; O'Dea, C. P.; Hughes, D. H.

    2003-04-01

    We present the final results from our deep Hubble Space Telescope (HST) imaging study of the host galaxies of radio-quiet quasars (RQQs), radio-loud quasars (RLQs) and radio galaxies (RGs). We describe and analyse new Wide Field & Planetary Camera 2 (WFPC2) R-band observations for 14 objects, which when combined with the first tranche of HST imaging reported in McLure et al., provide a complete and consistent set of deep, red, line-free images for statistically matched samples of 13 RQQs, 10 RLQs and 10 RGs in the redshift band 0.1 < z < 0.25. We also report the results of new deep VLA imaging that has yielded a 5-GHz detection of all but one of the 33 active galactic nuclei (AGN) in our sample. Careful modelling of our images, aided by a high dynamic-range point spread function, has allowed us to determine accurately the morphology, luminosity, scalelength and axial ratio of every host galaxy in our sample. Armed with this information we have undertaken a detailed comparison of the properties of the hosts of these three types of powerful AGN, both internally and with the galaxy population in general. We find that spheroidal hosts become more prevalent with increasing nuclear luminosity such that, for nuclear luminosities MV < -23.5, the hosts of both radio-loud and radio-quiet AGN are virtually all massive ellipticals. Moreover, we demonstrate that the basic properties of these hosts are indistinguishable from those of quiescent, evolved, low-redshift ellipticals of comparable mass. This result rules out the possibility that radio-loudness is determined by host-galaxy morphology, and also sets severe constraints on evolutionary schemes that attempt to link low-z ultraluminous infrared galaxies with RQQs. Instead, we show that our results are as expected given the relationship between black hole and spheroid mass established for nearby galaxies, and apply this relation to estimate the mass of the black hole in each object. The results agree remarkably well with

  5. Fast outflows and star formation quenching in quasar host galaxies

    NASA Astrophysics Data System (ADS)

    Carniani, S.; Marconi, A.; Maiolino, R.; Balmaverde, B.; Brusa, M.; Cano-Díaz, M.; Cicone, C.; Comastri, A.; Cresci, G.; Fiore, F.; Feruglio, C.; La Franca, F.; Mainieri, V.; Mannucci, F.; Nagao, T.; Netzer, H.; Piconcelli, E.; Risaliti, G.; Schneider, R.; Shemmer, O.

    2016-06-01

    Negative feedback from active galactic nuclei (AGN) is considered a key mechanism in shaping galaxy evolution. Fast, extended outflows are frequently detected in the AGN host galaxies at all redshifts and luminosities, both in ionised and molecular gas. However, these outflows are only potentially able to quench star formation, and we are still lacking decisive evidence of negative feedback in action. Here we present observations obtained with the Spectrograph for INtegral Field Observations in the Near Infrared (SINFONI) H- and K-band integral-field of two quasars at z ~ 2.4 that are characterised by fast, extended outflows detected through the [Oiii]λ5007 line. The high signal-to-noise ratio of our observations allows us to identify faint narrow (FWHM< 500 km s-1) and spatially extended components in [Oiii]λ5007 and Hα emission associated with star formation in the host galaxy. This star formation powered emission is spatially anti-correlated with the fast outflows. The ionised outflows therefore appear to be able to suppress star formation in the region where the outflow is expanding. However, the detection of narrow spatially extended Hα emission indicates star formation rates of at least ~50-90 M⊙ yr-1, suggesting either that AGN feedback does not affect the whole galaxy or that many feedback episodes are required before star formation is completely quenched. On the other hand, the narrow Hα emission extending along the edges of the outflow cone may also lead also to a positive feedback interpretation. Our results highlight the possible double role of galaxy-wide outflows in host galaxy evolution. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile, P.ID: 086.B-0579(A) and 091.A-0261(A).The reduced data cubes are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/591/A28

  6. VizieR Online Data Catalog: SDSS-RM project: z<1 QSO host galaxies (Matsuoka+, 2015)

    NASA Astrophysics Data System (ADS)

    Matsuoka, Y.; Strauss, M. A.; Shen, Y.; Brandt, W. N.; Greene, J. E.; Ho, L. C.; Schneider, D. P.; Sun, M.; Trump, J. R.

    2016-01-01

    We use the data acquired in the Sloan Digital Sky Survey Reverberation Mapping (SDSS-RM) project, in which a single spectroscopic field was repeatedly observed to explore the variability of quasars. The full technical details of the project are found in Shen et al. (2015, J/ApJS/216/4). SDSS-RM was conducted during the dark/gray time in the final season (2013-2014) of the SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS; Dawson et al. 2013AJ....145...10D). The target field (centered at RAJ2000=14:14:49.00, DEJ2000=+53:05:00.0) coincides with the Panoramic Survey Telescope & Rapid Response System 1 (Pan-STARRS 1; Kaiser et al. 2010SPIE.7733E..0EK) Medium Deep Field MD07, which lies within the Canada-France-Hawaii Telescope Legacy Survey W3 field. (1 data file).

  7. Dissecting High-Redshift Galaxies with GRBs: Three Hosts at z 6 Observed with HST

    NASA Astrophysics Data System (ADS)

    McGuire, J. T. W.

    2016-10-01

    The first detection of three GRB hosts at z 6 is presented, along with their comparison to Lyman-break galaxies, potential star formation histories and a brief look at their impact on the high-redshift galaxy luminosity function.

  8. Quasar Host Galaxies and the MSMBH–σ* Relation

    NASA Astrophysics Data System (ADS)

    Sheinis, A. I.; López-Sánchez, Á. R.

    2017-02-01

    We analyze the emission line profiles detected in deep optical spectra of quasars to derive the mass of their super-massive black holes (SMBH) following the single-epoch virial method. Our sample consists in six radio-loud (RL) quasars and four radio-quiet (RQ) quasars. We carefully fit a broad and narrow Gaussian component for each emission line in both the Hβ (10 objects) and Hα regions (5 objects). A very good agreement of the derived SMBH masses, {M}{SMBH}, is found using the fitted broad Hβ and Hα emission lines. We compare our {M}{SMBH} results with those found by previous studies. We study the relationship between the {M}{SMBH} of the quasar and the stellar velocity dispersion, {σ }* , of the host galaxy. We use the measured {M}{SMBH} and {σ }* to investigate the {M}{SMBH}–{σ }* relation for both the RL and radio-quiet subsamples. Besides the scatter, we find a good agreement between radio-quiet quasars and AGN+quiescent galaxies and between RL quasars and AGN. Our analysis does not support the hypothesis of using σ([O iii] λ5007) as a surrogate for stellar velocity dispersions in high-mass, high-luminosity quasars. We also investigate the relationship between the 5 GHz radio-continuum luminosity, {L}5{GHz}, of the quasar host galaxy with both {M}{SMBH} and {σ }* . We do not find any correlation between {L}5{GHz} and {M}{SMBH}, although we observe a trend that galaxies with larger stellar velocity dispersions have larger {L}5{GHz}. Using the results of our fitting for the narrow emission lines of [O iii] λ5007 and [N ii] λ6583 we estimate the gas-phase oxygen abundance of six quasars, being sub-solar in all cases.

  9. EARLY-TYPE HOST GALAXIES OF TYPE II AND Ib SUPERNOVAE

    SciTech Connect

    Suh, Hyewon; Jeong, Hyunjin; Yi, Sukyoung K.; Yoon, Sung-chul

    2011-04-01

    Recent studies find that some early-type galaxies host Type II or Ibc supernovae (SNe II, Ibc). This may imply recent star formation activities in these SNe host galaxies, but a massive star origin of the SNe Ib so far observed in early-type galaxies has been questioned because of their intrinsic faintness and unusually strong Ca lines shown in the nebular phase. To address the issue, we investigate the properties of early-type SNe host galaxies using the data with Galaxy Evolution Explorer (GALEX) ultraviolet photometry and the Sloan Digital Sky Survey optical data. Our sample includes eight SNe II and one peculiar SN Ib (SN 2000ds) host galaxies as well as 32 SN Ia host galaxies. The host galaxy of SN 2005cz, another peculiar SN Ib, is also analyzed using the GALEX data and the NASA/IPAC Extragalactic Database optical data. We find that the NUV-optical colors of SN II/Ib host galaxies are systematically bluer than those of SN Ia host galaxies, and some SN II/Ib host galaxies with NUV - r colors markedly bluer than the others exhibit strong radio emission. We perform a stellar population synthesis analysis and find a clear signature of recent star formation activities in most of the SN II/Ib host galaxies. Our results generally support the association of the SNe II/Ib hosted in early-type galaxies with core collapse of massive stars. We briefly discuss implications for the progenitors of the peculiar SNe Ib 2000ds and 2005cz.

  10. Simple Stellar Population Modeling of Quasar Host Galaxies with Diffusion K-Means Test Results

    NASA Astrophysics Data System (ADS)

    Mosby, Gregory; Moravec, E. A.; Tremonti, C. A.; Wolf, M. J.

    2013-01-01

    In the last decade, the correlation of the masses of supermassive black holes (SMBHs) and their host galaxy stellar spheroid velocity dispersions (the M-sigma relation) was greeted as clear evidence for the co-evolution of host galaxies and their SMBHs. However, studies in the last five years have posited that this relation could arise from central-limit properties of hierarchical formation alone. To address the question of whether and how often the SMBHs evolve with their host galaxies, it is necessary to look at galaxies whose SMBHs are actively growing—quasars—and determine the host galaxy properties. The central nuclei of quasar host galaxies complicate this type of study because their high luminosity tends to wash out their host galaxies. But, by using 3-D spectroscopy with the integral field unit (IFU) Sparsepak on the WIYN telescope, we have shown that the quasar light can be mostly isolated to one fiber in order to obtain the spectra of the quasar and the host galaxy concurrently. We can then model simultaneously the scattered quasar light and the stellar populations in the host galaxy fiber using a new simple stellar population (SSP) modeling method called diffusion k-means (DFK). The objectives of the research presented in this poster are to model synthetic quasar host galaxies using a DFK basis and a more traditional basis, compare the accuracy of both modeling methods, and test the affects of various prescriptions for masking the quasar lines in the host galaxy fiber. We present results from our SSP modeling and Markov Chain Monte Carlo (MCMC) results for DFK and traditional modeling schemes using synthetic data. By determining and then using the more robust stellar population modeling method, we can more confidently study quasar host galaxies to answer remaining questions in galaxy evolution. This work was partially supported by a National Science Foundation Graduate Fellowship (NSF Grant DGE-0718123) and through the NSF's REU program (NSF Award

  11. Herschel Observed Stripe 82 Quasars and Their Host Galaxies: Connections between AGN Activity and host Galaxy Star Formation

    NASA Astrophysics Data System (ADS)

    Dong, X. Y.; Wu, Xue-Bing

    2016-06-01

    In this work, we present a study of 207 quasars selected from the Sloan Digital Sky Survey quasar catalogs and the Herschel Stripe 82 survey. Quasars within this sample are high-luminosity quasars with a mean bolometric luminosity of 1046.4 erg s-1. The redshift range of this sample is within z < 4, with a mean value of 1.5 ± 0.78. Because we only selected quasars that have been detected in all three Herschel-SPIRE bands, the quasar sample is complete yet highly biased. Based on the multi-wavelength photometric observation data, we conducted a spectral energy distribution (SED) fitting through UV to FIR. Parameters such as active galactic nucleus (AGN) luminosity, far-IR (FIR) luminosity, stellar mass, as well as many other AGN and galaxy properties are deduced from the SED fitting results. The mean star formation rate (SFR) of the sample is 419 M ⊙ yr-1 and the mean gas mass is ˜1011.3 M ⊙. All of these results point to an IR luminous quasar system. Compared with star formation main sequence (MS) galaxies, at least 80 out of 207 quasars are hosted by starburst galaxies. This supports the statement that luminous AGNs are more likely to be associated with major mergers. The SFR increases with the redshift up to z = 2. It is correlated with the AGN bolometric luminosity, where {L}{{FIR}}\\propto {L}{{Bol}}0.46+/- 0.03. The AGN bolometric luminosity is also correlated with the host galaxy mass and gas mass. Yet the correlation between L FIR and L Bol has higher significant level, implies that the link between AGN accretion and the SFR is more primal. The M BH/M * ratio of our sample is 0.02, higher than the value 0.005 in the local universe. It might indicate an evolutionary trend of the M BH-M * scaling relation.

  12. The host galaxy of a fast radio burst.

    PubMed

    Keane, E F; Johnston, S; Bhandari, S; Barr, E; Bhat, N D R; Burgay, M; Caleb, M; Flynn, C; Jameson, A; Kramer, M; Petroff, E; Possenti, A; van Straten, W; Bailes, M; Burke-Spolaor, S; Eatough, R P; Stappers, B W; Totani, T; Honma, M; Furusawa, H; Hattori, T; Morokuma, T; Niino, Y; Sugai, H; Terai, T; Tominaga, N; Yamasaki, S; Yasuda, N; Allen, R; Cooke, J; Jencson, J; Kasliwal, M M; Kaplan, D L; Tingay, S J; Williams, A; Wayth, R; Chandra, P; Perrodin, D; Berezina, M; Mickaliger, M; Bassa, C

    2016-02-25

    In recent years, millisecond-duration radio signals originating in distant galaxies appear to have been discovered in the so-called fast radio bursts. These signals are dispersed according to a precise physical law and this dispersion is a key observable quantity, which, in tandem with a redshift measurement, can be used for fundamental physical investigations. Every fast radio burst has a dispersion measurement, but none before now have had a redshift measurement, because of the difficulty in pinpointing their celestial coordinates. Here we report the discovery of a fast radio burst and the identification of a fading radio transient lasting ~6 days after the event, which we use to identify the host galaxy; we measure the galaxy's redshift to be z = 0.492 ± 0.008. The dispersion measure and redshift, in combination, provide a direct measurement of the cosmic density of ionized baryons in the intergalactic medium of ΩIGM = 4.9 ± 1.3 per cent, in agreement with the expectation from the Wilkinson Microwave Anisotropy Probe, and including all of the so-called 'missing baryons'. The ~6-day radio transient is largely consistent with the radio afterglow of a short γ-ray burst, and its existence and timescale do not support progenitor models such as giant pulses from pulsars, and supernovae. This contrasts with the interpretation of another recently discovered fast radio burst, suggesting that there are at least two classes of bursts.

  13. Gemini 3D spectroscopy of BAL+IR+FeII QSOs - II. IRAS 04505-2958, an explosive QSO with hypershells and a new scenario for galaxy formation and galaxy end phase

    NASA Astrophysics Data System (ADS)

    Lípari, S.; Bergmann, M.; Sanchez, S. F.; Garcia-Lorenzo, B.; Terlevich, R.; Mediavilla, E.; Taniguchi, Y.; Zheng, W.; Punsly, B.; Ahumada, A.; Merlo, D.

    2009-09-01

    From a study of broad absorption line (BAL) + infrared (IR) + FeII quasi-stellar objects (QSOs) [using deep Gemini Multi-Object Spectrograph Integral Field Unit (GMOS-IFU) spectroscopy], new results are presented for IRAS 04505-2958. Specifically, we have studied in detail the outflow (OF) process at two large galactic scales: (i) two blobs/shells at radius r ~ 1.1 and 2.2 kpc, and (ii) an external hypergiant shell at r ~ 11 kpc. In addition, the presence of two very extended hypergiant shells at r ~ 60-80 kpc is also discussed. From this GMOS study the following main results were obtained. (i) For the external hypergiant shell, the kinematics GMOS maps of the ionized gas ([OII], [NeIII], [OIII], Hβ) show a small-scale bipolar OF, with similar properties to those observed in the prototype of exploding external supershells: NGC 5514. (ii) Three main knots - of this hypershell S3 - show the presence of a young starburst. (iii) The two internal shells show OF components with typical properties of nuclear shells. (iv) The two blobs and the hypershell are aligned at PA ~ 131° showing bipolar OF shape at ~10-15 kpc scale. In addition, the more external shells (at ~60-80 kpc scale) are aligned at PA ~ 40° also with bipolar OF shape (perpendicular to the more internal OF). (v) A strong blue continuum and multiple emission-line components were detected in all the GMOS fields. The new GMOS data show a good agreement with an extreme + explosive OF scenario for IRAS 04505-2958, in which part of the interstellar medium (ISM) of the host galaxy was ejected (in multiple shells). This extreme OF could also be associated with two main processes in the evolution of QSOs: (i) the formation of companion/satellite galaxies by giant explosions; and (ii) to define the final mass of the host galaxy, and even if the explosive nuclear OF is extremely energetic, this process could disrupt an important fraction of the host galaxy. Finally, the generation of ultra-high-energy cosmic rays

  14. Host Galaxies of Type Ia Supernovae from the Nearby Supernova Factory

    NASA Astrophysics Data System (ADS)

    Childress, M.; Aldering, G.; Antilogus, P.; Aragon, C.; Bailey, S.; Baltay, C.; Bongard, S.; Buton, C.; Canto, A.; Cellier-Holzem, F.; Chotard, N.; Copin, Y.; Fakhouri, H. K.; Gangler, E.; Guy, J.; Hsiao, E. Y.; Kerschhaggl, M.; Kim, A. G.; Kowalski, M.; Loken, S.; Nugent, P.; Paech, K.; Pain, R.; Pecontal, E.; Pereira, R.; Perlmutter, S.; Rabinowitz, D.; Rigault, M.; Runge, K.; Scalzo, R.; Smadja, G.; Tao, C.; Thomas, R. C.; Weaver, B. A.; Wu, C.

    2013-06-01

    We present photometric and spectroscopic observations of galaxies hosting Type Ia supernovae (SNe Ia) observed by the Nearby Supernova Factory. Combining Galaxy Evolution Explorer (GALEX) UV data with optical and near-infrared photometry, we employ stellar population synthesis techniques to measure SN Ia host galaxy stellar masses, star formation rates (SFRs), and reddening due to dust. We reinforce the key role of GALEX UV data in deriving accurate estimates of galaxy SFRs and dust extinction. Optical spectra of SN Ia host galaxies are fitted simultaneously for their stellar continua and emission lines fluxes, from which we derive high-precision redshifts, gas-phase metallicities, and Hα-based SFRs. With these data we show that SN Ia host galaxies present tight agreement with the fiducial galaxy mass-metallicity relation from Sloan Digital Sky Survey (SDSS) for stellar masses log(M */M ⊙) > 8.5 where the relation is well defined. The star formation activity of SN Ia host galaxies is consistent with a sample of comparable SDSS field galaxies, though this comparison is limited by systematic uncertainties in SFR measurements. Our analysis indicates that SN Ia host galaxies are, on average, typical representatives of normal field galaxies.

  15. Low-redshift quasars in the SDSS Stripe 82: associated companion galaxies and signature of star formation

    NASA Astrophysics Data System (ADS)

    Bettoni, D.; Falomo, R.; Kotilainen, J. K.; Karhunen, K.

    2017-04-01

    We obtained optical spectroscopy of close (<80 kpc) companion objects of a sample of 12 low-redshift quasars (z < 0.3) selected from the SDSS Stripe82 area and that are in the subsample of 52 QSOs for which both multicolour host galaxies properties and galaxy environment were recently investigated in detail. We found that for 8 out of 12 sources the companion galaxy is associated with the QSO having a difference of radial velocity that is less than 400 km s-1. Many of these associated companions exhibit [OII] λ3727 Å emission lines suggestive of episodes of (recent) star formation possibly induced by past interactions. The star formation rate of the companion galaxies as derived from [O II] line luminosity is, however, modest, with a median value of 1.0 ± 0.8 M⊙ yr-1, and the emission lines are barely consistent with expectation from gas ionization by the QSO. The role of the QSO for inducing star formation in close companion galaxies appears meager. For three objects we also detect the starlight spectrum of the QSO host galaxy, which is characterized by absorption lines of old stellar population and [O II] emission line.

  16. VizieR Online Data Catalog: Properties of SN host galaxies (Kelly+, 2014)

    NASA Astrophysics Data System (ADS)

    Kelly, P. L.; Filippenko, A. V.; Modjaz, M.; Kocevski, D.

    2017-03-01

    We study the host galaxies of both nearby (z<0.2) core-collapse SNe discovered by "galaxy-untargeted" transient searches (e.g., the Palomar Transient Factory (PTF); Rau et al., 2009PASP..121.1334R; Law et al., 2009PASP..121.1395L), which do not target specific potential hosts or z<1.2 LGRBs detected by gamma-ray satellites. We use the SDSS spectroscopic sample to build a control sample of low-redshift star-forming galaxies and SDSS photometry and spectroscopy to measure properties of both the sample of low-redshift star-forming galaxies and the host galaxies of the nearby SNe. For the host galaxies of z<1.2 LGRBs, we estimate host properties using published photometry and HST imaging. (2 data files).

  17. Quasar Host Galaxies/Neptune Rotation/Galaxy Building Blocks/Hubble Deep Field/Saturn Storm

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Computerized animations simulate a quasar erupting in the core of a normal spiral galaxy, the collision of two interacting galaxies, and the evolution of the universe. Hubble Space Telescope (HST) images show six quasars' host galaxies (including spirals, ellipticals, and colliding galaxies) and six clumps of galaxies approximately 11 billion light years away. A false color time lapse movie of Neptune displays the planet's 16-hour rotation, and the evolution of a storm on Saturn is seen though a video of the planet's rotation. A zoom sequence starts with a ground-based image of the constellation Ursa major and ends with the Hubble Deep Field through progressively narrower and deeper views.

  18. An observational study of quasar host galaxies, radio galaxies, and lyman alpha emitters

    NASA Astrophysics Data System (ADS)

    Wold, Isak George Bayard

    In this thesis I provide observational constraints on quasar host galaxies, radio galaxies, and Lyman Alpha Emitters (LAEs). I develop and implement a method to provide stellar age constraints for the host galaxies of nearby (z<0.3) quasars. The observational strategy is to spectroscopically observe quasar host galaxies offset from the bright central point source to maximize the signal-to-noise of the stellar light. The central quasar is also spectroscopically observed, so that any nuclear light scattered into our off-axis spectrum can be efficiently modeled and subtracted. The reliability of my technique is tested via a Monte-Carlo routine in which the correspondence between synthetic spectra with known parameters and the model output is determined. Application of this model to a preliminary sample of 10 objects is presented and compared to previous studies. I present 1.4 GHz catalogs for the cluster fields A370 and A2390 observed with the Very Large Array. These are two of the deepest radio images of cluster fields ever taken. I construct differential number counts for each field and find results consistent with previous studies. I emphasize the need to account for cosmic variance. These high resolution, ultra-deep radio catalogs will be vital to future multiwavelength studies. Finally, I apply a newly developed search method to all of the deep GALEX grism fields, which correspond to some of the most intensively studied regions in the sky. My work provides the first large sample of z=0.67-1.16 LAEs (N=60) that can be used to investigate the physical properties of these galaxies. I catalog the candidate z=1 LAE samples in each field and give optical redshifts from both archival and newly obtained observations. With X-ray, UV, and optical data, I determine the false detection rate (cases where the emission line is either not confirmed or is not Lya) and the AGN contamination rate of my sample. With the remaining LAEs, I compute the LAE galaxy luminosity function

  19. The Hubble Space Telescope Survey of BL Lacertae Objects. IV. Infrared Imaging of Host Galaxies

    NASA Astrophysics Data System (ADS)

    Scarpa, Riccardo; Urry, C. Megan; Padovani, Paolo; Calzetti, Daniela; O'Dowd, Matthew

    2000-11-01

    The Hubble Space Telescope NICMOS Camera 2 was used for H-band imaging of 12 BL Lacertae objects taken from the larger sample observed with the WFPC2 in the R band by Urry and coworkers and Scarpa and coworkers. Ten of the 12 BL Lacs are clearly resolved, and the detected host galaxies are large, bright ellipticals with average absolute magnitude =-26.2+/-0.45 mag and effective radius =10+/-5 kpc. The rest-frame integrated color of the host galaxies is on average =2.3+/-0.3, consistent with the value for both radio galaxies and normal, nonactive elliptical galaxies and indicating that the dominant stellar population is old. The host galaxies tend to be bluer in their outer regions than in their cores, with average color gradient Δ(R-H)/Δlogr=-0.2 mag, again consistent with results for normal nonactive elliptical galaxies. The infrared Kormendy relation, derived for the first time for BL Lac host galaxies, is μe=3.8logre+14.8, fully in agreement with the relation for normal ellipticals. The close similarity between BL Lac host galaxies and normal ellipticals suggests that the active nucleus has surprisingly little effect on the host galaxy. This supports a picture in which all elliptical galaxies harbor black holes that can be actively accreting for some fraction of their lifetime.

  20. ON THE COSMIC EVOLUTION OF THE SCALING RELATIONS BETWEEN BLACK HOLES AND THEIR HOST GALAXIES: BROAD-LINE ACTIVE GALACTIC NUCLEI IN THE zCOSMOS SURVEY

    SciTech Connect

    Merloni, A.; Bongiorno, A.; Brusa, M.; Bolzonella, M.; Comastri, A.; Gilli, R.; Lusso, E.; Mignoli, M.; Civano, F.; Elvis, M.; Hao, H.; Fiore, F.; Jahnke, K.; Koekemoer, A. M.; Mainieri, V.; Miyaji, T.; Renzini, A.; Salvato, M.; Silverman, J.; Trump, J.

    2010-01-01

    We report on the measurement of the physical properties (rest-frame K-band luminosity and total stellar mass) of the hosts of 89 broad-line (type-1) active galactic nuclei (AGNs) detected in the zCOSMOS survey in the redshift range 1 < z < 2.2. The unprecedented multi-wavelength coverage of the survey field allows us to disentangle the emission of the host galaxy from that of the nuclear black hole in their spectral energy distributions (SEDs). We derive an estimate of black hole masses through the analysis of the broad Mg II emission lines observed in the medium-resolution spectra taken with VIMOS/VLT as part of the zCOSMOS project. We found that, as compared to the local value, the average black hole to host-galaxy mass ratio appears to evolve positively with redshift, with a best-fit evolution of the form (1+z){sup 0.68+}-{sup 0.12+0.6{sub -0.3}}, where the large asymmetric systematic errors stem from the uncertainties in the choice of initial mass function, in the calibration of the virial relation used to estimate BH masses and in the mean QSO SED adopted. On the other hand, if we consider the observed rest-frame K-band luminosity, objects tend to be brighter, for a given black hole mass, than those on the local M{sub BH}-M{sub K} relation. This fact, together with more indirect evidence from the SED fitting itself, suggests that the AGN hosts are likely actively star-forming galaxies. A thorough analysis of observational biases induced by intrinsic scatter in the scaling relations reinforces the conclusion that an evolution of the M{sub BH}-M{sub *} relation must ensue for actively growing black holes at early times: either its overall normalization, or its intrinsic scatter (or both) appear to increase with redshift. This can be interpreted as signature of either a more rapid growth of supermassive black holes at high redshift, a change of structural properties of AGN hosts at earlier times, or a significant mismatch between the typical growth times of

  1. Host galaxy spectra and consequences for supernova typing from the SDSS SN survey

    SciTech Connect

    Olmstead, Matthew D.; Brown, Peter J.; Brownstein, Joel R.; Dawson, Kyle S.; Sako, Masao; Gupta, Ravi R.; Bassett, Bruce; Kunz, Martin; Bizyaev, Dmitry; Brinkmann, J.; Brewington, Howard; Ebelke, Garrett L.; Campbell, Heather; D'Andrea, Chris B.; Lampeitl, Hubert; Frieman, Joshua A.; Galbany, Lluís; Garnavich, Peter; Hlozek, Renee; Jha, Saurabh W.; and others

    2014-04-01

    We present the spectroscopy from 5254 galaxies that hosted supernovae (SNe) or other transient events in the Sloan Digital Sky Survey II (SDSS-II). Obtained during SDSS-I, SDSS-II, and the Baryon Oscillation Spectroscopic Survey, this sample represents the largest systematic, unbiased, magnitude limited spectroscopic survey of SN host galaxies. Using the host galaxy redshifts, we test the impact of photometric SN classification based on SDSS imaging data with and without using spectroscopic redshifts of the host galaxies. Following our suggested scheme, there are a total of 1166 photometrically classified SNe Ia when using a flat redshift prior and 1126 SNe Ia when the host spectroscopic redshift is assumed. For 1024 (87.8%) candidates classified as likely SNe Ia without redshift information, we find that the classification is unchanged when adding the host galaxy redshift. Using photometry from SDSS imaging data and the host galaxy spectra, we also report host galaxy properties for use in future analysis of SN astrophysics. Finally, we investigate the differences in the interpretation of the light curve properties with and without knowledge of the redshift. Without host galaxy redshifts, we find that SALT2 light curve fits are systematically biased toward lower photometric redshift estimates and redder colors in the limit of low signal-to-noise data. The general improvements in performance of the light curve fitter and the increased diversity of the host galaxy sample highlights the importance of host galaxy spectroscopy for current photometric SN surveys such as the Dark Energy Survey and future surveys such as the Large Synoptic Survey Telescope.

  2. Host Galaxy Spectra and Consequences for SN Typing from the SDSS SN Survey

    SciTech Connect

    Olmstead, Matthew D.; Brown, Peter J.; Sako, Masao; Bassett, Bruce; Bizyaev, Dmitry; Brinkmann, J.; Brownstein, Joel R.; Brewington, Howard; Campbell, Heather; D’Andrea, Chris B.; Dawson, Kyle S.; Ebelke, Garrett L.; Frieman, Joshua A.; Galbany, Lluís; Garnavich, Peter; Gupta, Ravi R.; Hlozek, Renee; Jha, Saurabh W.; Kunz, Martin; Lampeitl, Hubert; Malanushenko, Elena; Malanushenko, Viktor; Marriner, John; Miquel, Ramon; Montero-Dorta, Antonio D.; Nichol, Robert C.; Oravetz, Daniel J.; Pan, Kaike; Schneider, Donald P.; Simmons, Audrey E.; Smith, Mathew; Snedden, Stephanie A.

    2014-03-06

    We present the spectroscopy from 5254 galaxies that hosted supernovae (SNe) or other transient events in the Sloan Digital Sky Survey II (SDSS-II). Obtained during SDSS-I, SDSS-II, and the Baryon Oscillation Spectroscopic Survey (BOSS), this sample represents the largest systematic, unbiased, magnitude limited spectroscopic survey of supernova (SN) host galaxies. Using the host galaxy redshifts, we test the impact of photometric SN classification based on SDSS imaging data with and without using spectroscopic redshifts of the host galaxies. Following our suggested scheme, there are a total of 1166 photometrically classified SNe Ia when using a flat redshift prior and 1126 SNe Ia when the host spectroscopic redshift is assumed. For 1024 (87.8%) candidates classified as likely SNe Ia without redshift information, we find that the classification is unchanged when adding the host galaxy redshift. Using photometry from SDSS imaging data and the host galaxy spectra, we also report host galaxy properties for use in future nalysis of SN astrophysics. Finally, we investigate the differences in the interpretation of the light curve properties with and without knowledge of the redshift. When using the SALT2 light curve fitter, we find a 21% increase in the number of fits that converge when using the spectroscopic redshift. Without host galaxy redshifts, we find that SALT2 light curve fits are systematically biased towards lower photometric redshift estimates and redder colors in the limit of low signal-to-noise data. The general improvements in performance of the light curve fitter and the increased diversity of the host galaxy sample highlights the importance of host galaxy spectroscopy for current photometric SN surveys such as the Dark Energy Survey and future surveys such as the Large Synoptic Survey Telescope.

  3. Host Galaxies of Young Dust-Reddened Quasars

    NASA Astrophysics Data System (ADS)

    Urrutia, T.; Lacy, M.; Becker, R.; Glikman, E.

    2009-10-01

    We present results on a multiwavelength campaign to identify the nature of dust-reddened Type 1 quasars. These quasars were selected by matching FIRST, 2MASS and very red optical counterparts with r'-K > 5. We find a very high fraction of Low Ionization Broad Absorption Line Quasars (LoBALs) among AGN selected with this method, perhaps a sign of quasar feedback. From X-ray observations and Balmer decrement measurements, the obscuring dust is most likely located in a cold absorber such as the host galaxy, rather than from a torus near the AGN. Hubble ACS imaging of a sub-sample of these sources showed a very high fraction of interacting and merging systems. The quasars appear to be very young in which dust from the merging galaxies is still settling in. Spitzer IRS and MIPS data show star formation signatures and deep Silicate absorption features in these objects, but overall the quasar is the dominant source in the Mid-infrared.

  4. The MOSDEF Survey: AGN Multi-wavelength Identification, Selection Biases, and Host Galaxy Properties

    NASA Astrophysics Data System (ADS)

    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

    2017-01-01

    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 (AGNs) at 1.4< z< 3.8. We obtain rest-frame optical spectra of galaxies and AGNs and use the BPT diagram to identify optical AGNs. We examine the uniqueness and overlap of the AGNs identified at different wavelengths. There is a strong bias against identifying AGNs at any wavelength in low-mass galaxies, and an additional bias against identifying IR AGNs in the most massive galaxies. AGN 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 AGNs are in less dusty galaxies with relatively higher SFR and optical AGNs in dusty galaxies with relatively lower SFR. X-ray AGN 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 AGNs in galaxies with similar physical properties as inactive galaxies, with no evidence for AGN activity in particular types of galaxies. This is consistent with AGNs being fueled stochastically in any star-forming host galaxy. We do not detect a significant correlation between SFR and AGN luminosity for individual AGN hosts, which may indicate the timescale difference between the growth of galaxies and their supermassive black holes.

  5. EARLY-TYPE HOST GALAXIES OF TYPE Ia SUPERNOVAE. I. EVIDENCE FOR DOWNSIZING

    SciTech Connect

    Kang, Yijung; Kim, Young-Lo; Lim, Dongwook; Chung, Chul; Lee, Young-Wook

    2016-03-15

    Type Ia supernova (SN Ia) cosmology provides the most direct evidence for the presence of dark energy. This result is based on the assumption that the lookback time evolution of SN Ia luminosity, after light curve corrections, would be negligible. Recent studies show, however, that the Hubble residual (HR) of SN Ia is correlated with the mass and morphology of host galaxies, implying the possible dependence of SN Ia luminosity on host galaxy properties. In order to investigate this more directly, we have initiated a spectroscopic survey for early-type host galaxies, for which population age and metallicity can be more reliably determined from the absorption lines. In this first paper of the series, we present here the results from high signal-to-noise ratio (≳100 per pixel) spectra for 27 nearby host galaxies in the southern hemisphere. For the first time in host galaxy studies, we find a significant (∼3.9σ) correlation between host galaxy mass (velocity dispersion) and population age, which is consistent with the “downsizing” trend among non-host early-type galaxies. This result is rather insensitive to the choice of population synthesis models. Since we find no correlation with metallicity, our result suggests that stellar population age is mainly responsible for the relation between host mass and HR. If confirmed, this would imply that the luminosity evolution plays a major role in the systematic uncertainties of SN Ia cosmology.

  6. The host galaxies and black hole-to-galaxy mass ratios of luminous quasars at z≃ 4

    NASA Astrophysics Data System (ADS)

    Targett, Thomas A.; Dunlop, James S.; McLure, Ross J.

    2012-03-01

    Deep K-band imaging of the most luminous z≃ 4 quasars currently offers the earliest possible view of the mass-dominant stellar populations of the host galaxies which house the first supermassive black holes in the Universe. This is because, until the advent of the James Webb Space Telescope, it is not possible to obtain the necessary deep, sub-arcsec resolution imaging at rest-frame wavelengths λrest > 4000 Å at any higher redshift. We here present and analyse the deepest, high-quality KS-band images ever obtained of luminous quasars at z≃ 4, in an attempt to determine the basic properties of their host galaxies less than 1 Gyr after the first recorded appearance of black holes with Mbh > 109 M⊙. To maximize the robustness of our results, we have carefully selected two Sloan Digital Sky Survey quasars at z≃ 4. With absolute magnitudes Mi < -28, these quasars are representative of the most luminous quasars known at this epoch, but they also, crucially, lie within 40 arcsec of comparably bright foreground stars (required for accurate point spread function definition), and have redshifts which ensure line-free KS-band imaging. The data were obtained in excellent seeing conditions (<0.4 arcsec) at the European Southern Observatory on the Very Large Telescope with integration times of ≃5.5 h per source. Via carefully controlled separation of host galaxy and nuclear light, we estimate the luminosities and stellar masses of the host galaxies, and set constraints on their half-light radii. The apparent KS-band magnitudes of the quasar host galaxies are consistent with those of luminous radio galaxies at comparable redshifts, suggesting that these quasar hosts are also among the most massive galaxies in existence at this epoch. However, the quasar hosts are a factor ˜5 smaller (= 1.8 kpc) than the host galaxies of luminous low-redshift quasars. We estimate the stellar masses of the z≃ 4 host galaxies to lie in the range 2-10 × 1011 M⊙, and use the C

  7. QSO selection in the ALHAMBRA survey

    NASA Astrophysics Data System (ADS)

    Matute, I.; Márquez, I.; Masegosa, J.; Perea, J.; Del Olmo, A.; Husillos, C.

    2011-11-01

    During the past decade photometric redshift (photo-z) determination for the extragalactic population has been drastically improved. This improvement has allow to close the gap between the several hundred thousand of objects per deg^2 detected in modern cosmological surveys and their identification through spectroscopic follow-ups. Only recently, a similar level of precision has been achieved for AGN as for normal galaxies. We characterize the efficiency of the ALHAMBRA survey to derive highly accurate photometric redshifts (photo-z) for the brightest of the AGN sample, the QSOs. This characterization is required before any further analysis whether it implies individual objects or statistical properties of the QSO population as a whole (e.g. luminosity functions). We present the results for the QSO photo-z calibration making use of the published spectroscopic information from other major cosmological surveys overlapping with ALHAMBRA (e.g. COSMOS, GOODS, SDSS, DEEP, SWIRE & AEGIS). With the appropriate selection of templates and priors, the analysis of the ALHAMBRA fields shows an excellent agreement between the spectro-z and photo-z, obtaining σ[Δ z/(1+z)] < 0.02 with a low fraction (<7%) of catastrophic failures.

  8. Type Ia Supernova Hubble Residuals and Host-Galaxy Properties

    SciTech Connect

    Nearby Supernova Factory; Kim, A. G.; Aldering, G.; Antilogus, P.; Aragon, C.; Bailey, S.; Baltay, C.; Bongard, S.; Buton, C.; Canto, A.; Cellier-Holzem, F.; Childress, M.; Chotard, N.; Copin, Y.; Fakhouri, H. K.; Feindt, U.; Fleury, M.; Gangler, E.; Greskovic, P.; Guy, J.; Kowalski, M.; Lombardo, S.; Nordin, J.; Nugent, P.; Pain, R.; Pecontal, E.; Pereira, R.; Perlmutter, S.; Rabinowitz, D.; Rigault, M.; Runge, K.; Saunders, C.; Scalzo, R.; Smadja, G.; Tao, C.; Thomas, R. C.; Weaver, B. A.

    2014-01-17

    Kim et al. (2013) [K13] introduced a new methodology for determining peak- brightness absolute magnitudes of type Ia supernovae from multi-band light curves. We examine the relation between their parameterization of light curves and Hubble residuals, based on photometry synthesized from the Nearby Supernova Factory spec- trophotometric time series, with global host-galaxy properties. The K13 Hubble residual step with host mass is 0.013 ? 0.031 mag for a supernova subsample with data coverage corresponding to the K13 training; at ? 1?, the step is not significant and lower than previous measurements. Relaxing the data coverage requirement the Hubble residual step with host mass is 0.045 ? 0.026 mag for the larger sample; a calculation using the modes of the distributions, less sensitive to outliers, yields a step of 0.019 mag. The analysis of this article uses K13 inferred luminosities, as distinguished from previous works that use magnitude corrections as a function of SALT2 color and stretch param- eters: Steps at> 2? significance are found in SALT2 Hubble residuals in samples split by the values of their K13 x(1) and x(2) light-curve parameters. x(1) affects the light- curve width and color around peak (similar to the∆m15 and stretch parameters), and x(2) affects colors, the near-UV light-curve width, and the light-curve decline 20 to 30 days after peak brightness. The novel light-curve analysis, increased parameter set, and magnitude corrections of K13 may be capturing features of SN Ia diversity arising from progenitor stellar evolution.

  9. Type Ia supernova Hubble residuals and host-galaxy properties

    SciTech Connect

    Kim, A. G.; Aldering, G.; Aragon, C.; Bailey, S.; Fakhouri, H. K.; Antilogus, P.; Bongard, S.; Canto, A.; Cellier-Holzem, F.; Fleury, M.; Guy, J.; Baltay, C.; Buton, C.; Feindt, U.; Greskovic, P.; Kowalski, M.; Childress, M.; Chotard, N.; Copin, Y.; Gangler, E. [Université de Lyon, F-69622 Lyon; Université de Lyon 1, Villeurbanne; CNRS and others

    2014-03-20

    Kim et al. introduced a new methodology for determining peak-brightness absolute magnitudes of type Ia supernovae from multi-band light curves. We examine the relation between their parameterization of light curves and Hubble residuals, based on photometry synthesized from the Nearby Supernova Factory spectrophotometric time series, with global host-galaxy properties. The K13 Hubble residual step with host mass is 0.013 ± 0.031 mag for a supernova subsample with data coverage corresponding to the K13 training; at <<1σ, the step is not significant and lower than previous measurements. Relaxing the data coverage requirement of the Hubble residual step with the host mass is 0.045 ± 0.026 mag for the larger sample; a calculation using the modes of the distributions, less sensitive to outliers, yields a step of 0.019 mag. The analysis of this article uses K13 inferred luminosities, as distinguished from previous works that use magnitude corrections as a function of SALT2 color and stretch parameters: steps at >2σ significance are found in SALT2 Hubble residuals in samples split by the values of their K13 x(1) and x(2) light-curve parameters. x(1) affects the light-curve width and color around peak (similar to the Δm {sub 15} and stretch parameters), and x(2) affects colors, the near-UV light-curve width, and the light-curve decline 20-30 days after peak brightness. The novel light-curve analysis, increased parameter set, and magnitude corrections of K13 may be capturing features of SN Ia diversity arising from progenitor stellar evolution.

  10. The Host Galaxies of High-Luminosity Obscured Quasars at 2.5

    NASA Astrophysics Data System (ADS)

    Ross, Nicholas; Strauss, M. A.; Greene, J. E.; Zakamska, N. L.; Brandt, W. N.; Alexandroff, R.; Liu, G.; Smith, P. S.; The SDSS-III BOSS Quasar Working Group

    2014-01-01

    Active Galactic Nuclei play a key role in the evolution of galaxies. However, very little is known about the host galaxies of the most luminous quasars at redshift 2.5, the epoch when massive black hole growth peaked. The brightness of the quasar itself, which can easily outshine a galaxy by a large factor, makes it very difficult to study emission from extended gas or stars in the host galaxy. However, we have imaged the extended emission from the host galaxies of a unique sample of six optically extinguished (Type II) luminous quasars with 2.5, with the Hubble Space Telescope (Cycle 20, GO 13014) using ACS/F814W to access the rest-frame near-ultraviolet, and WFC3/F160W for the rest-frame optical longward of 4000A. These objects are selected from the spectroscopic database of the SDSS/Baryon Oscillation Spectroscopic Survey to have strong, narrow emission lines and weak continua. With these images, we have quantified the luminosity, morphology, and dynamical state of the host galaxies, and searched for extended scattered light from the obscured central engine. These observations are the first comprehensive study of both host galaxy light and scattered light in high-luminosity quasars at the epoch of maximum black hole growth, and give insights into the relationship between host galaxies and black holes during this important, and yet largely unexplored period.

  11. PROPERTIES OF QSO METAL-LINE ABSORPTION SYSTEMS AT HIGH REDSHIFTS: NATURE AND EVOLUTION OF THE ABSORBERS AND NEW EVIDENCE ON ESCAPE OF IONIZING RADIATION FROM GALAXIES

    SciTech Connect

    Boksenberg, Alec; Sargent, Wallace L. W.

    2015-05-15

    Using Voigt-profile-fitting procedures on Keck High Resolution Spectrograph spectra of nine QSOs, we identify 1099 C IV absorber components clumped in 201 systems outside the Lyman forest over 1.6 ≲ z ≲ 4.4. With associated Si IV, C II, Si II  and N V where available, we investigate the bulk statistical and ionization properties of the components and systems and find no significant change in redshift for C IV and Si IV while C II, Si II  and N V change substantially. The C IV components exhibit strong clustering, but no clustering is detected for systems on scales from 150 km s{sup –1} out to 50,000 km s{sup –1}. We conclude that the clustering is due entirely to the peculiar velocities of gas present in the circumgalactic media of galaxies. Using specific combinations of ionic ratios, we compare our observations with model ionization predictions for absorbers exposed to the metagalactic ionizing radiation background augmented by proximity radiation from their associated galaxies and find that the generally accepted means of radiative escape by transparent channels from the internal star-forming sites is spectrally not viable for our stronger absorbers. We develop an active scenario based on runaway stars with resulting changes in the efflux of radiation that naturally enable the needed spectral convergence, and in turn provide empirical indicators of morphological evolution in the associated galaxies. Together with a coexisting population of relatively compact galaxies indicated by the weaker absorbers in our sample, the collective escape of radiation is sufficient to maintain the intergalactic medium ionized over the full range 1.9 < z ≲ 4.4.

  12. Properties of QSO Metal-line Absorption Systems at High Redshifts: Nature and Evolution of the Absorbers and New Evidence on Escape of Ionizing Radiation from Galaxies

    NASA Astrophysics Data System (ADS)

    Boksenberg, Alec; Sargent, Wallace L. W.

    2015-05-01

    Using Voigt-profile-fitting procedures on Keck High Resolution Spectrograph spectra of nine QSOs, we identify 1099 C IV absorber components clumped in 201 systems outside the Lyman forest over 1.6 <~ z <~ 4.4. With associated Si IV, C II, Si II and N V where available, we investigate the bulk statistical and ionization properties of the components and systems and find no significant change in redshift for C IV and Si IV while C II, Si II and N V change substantially. The C IV components exhibit strong clustering, but no clustering is detected for systems on scales from 150 km s-1 out to 50,000 km s-1. We conclude that the clustering is due entirely to the peculiar velocities of gas present in the circumgalactic media of galaxies. Using specific combinations of ionic ratios, we compare our observations with model ionization predictions for absorbers exposed to the metagalactic ionizing radiation background augmented by proximity radiation from their associated galaxies and find that the generally accepted means of radiative escape by transparent channels from the internal star-forming sites is spectrally not viable for our stronger absorbers. We develop an active scenario based on runaway stars with resulting changes in the efflux of radiation that naturally enable the needed spectral convergence, and in turn provide empirical indicators of morphological evolution in the associated galaxies. Together with a coexisting population of relatively compact galaxies indicated by the weaker absorbers in our sample, the collective escape of radiation is sufficient to maintain the intergalactic medium ionized over the full range 1.9 < z <~ 4.4. The data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck

  13. Comparing the host galaxies of type Ia, type II, and type Ibc supernovae

    SciTech Connect

    Shao, X.; Liang, Y. C.; Chen, X. Y.; Zhong, G. H.; Deng, L. C.; Zhang, B.; Shi, W. B.; Zhou, L.; Dennefeld, M.; Hammer, F.; Flores, H. E-mail: ycliang@bao.ac.cn

    2014-08-10

    We compare the host galaxies of 902 supernovae (SNe), including SNe Ia, SNe II, and SNe Ibc, which are selected by cross-matching the Asiago Supernova Catalog with the Sloan Digital Sky Survey (SDSS) Data Release 7. We selected an additional 213 galaxies by requiring the light fraction of spectral observations to be >15%, which could represent well the global properties of the galaxies. Among these 213 galaxies, 135 appear on the Baldwin-Phillips-Terlevich diagram, which allows us to compare the hosts in terms of whether they are star-forming (SF) galaxies, active galactic nuclei (AGNs; including composites, LINERs, and Seyfert 2s) or absorption-line galaxies (Absorps; i.e., their related emission lines are weak or non-existent). The diagrams related to the parameters D{sub n}(4000), Hδ{sub A}, stellar masses, star formation rates (SFRs), and specific SFRs for the SNe hosts show that almost all SNe II and most of the SNe Ibc occur in SF galaxies, which have a wide range of stellar masses and low D{sub n}(4000). The SNe Ia hosts as SF galaxies following similar trends. A significant fraction of SNe Ia occurs in AGNs and absorption-line galaxies, which are massive and have high D{sub n}(4000). The stellar population analysis from spectral synthesis fitting shows that the hosts of SNe II have a younger stellar population than hosts of SNe Ia. These results are compared with those of the 689 comparison galaxies where the SDSS fiber captures less than 15% of the total light. These comparison galaxies appear biased toward higher 12+log(O/H) (∼0.1 dex) at a given stellar mass. Therefore, we believe the aperture effect should be kept in mind when the properties of the hosts for different types of SNe are discussed.

  14. The Luminosity Function of the Host Galaxies of QSOs and BL Lac Objects

    NASA Astrophysics Data System (ADS)

    Carangelo, Nicoletta; Falomo, Renato; Treves, Aldo

    A clear insight of the galaxies hosting active galactic nuclei is of fundamental importance for understanding the processes of galaxies and nuclei formation and their cosmic evolution. A good characterization of the host galaxies properties requires images of excellent quality in order to disentangle the light of the galaxy from that of the bright nucleus. To this aim HST has provided a major improvement of data on QSOs (Disney et al. 1995; Bahcall et al. 1996,1997; Boyce et al. 1998; McLure et al. 1999; Hamilton et al. 2000; Kukula et al. 2001) and BL Lacs (Scarpa et al. 2000, Urry et al. 2000).

  15. Modeling The GRB Host Galaxy Mass Distribution: Are GRBs Unbiased Tracers of Star Formation?

    SciTech Connect

    Kocevski, Daniel; West, Andrew A.; Modjaz, Maryam; /UC, Berkeley, Astron. Dept.

    2009-08-03

    We model the mass distribution of long gamma-ray burst (GRB) host galaxies given recent results suggesting that GRBs occur in low metallicity environments. By utilizing measurements of the redshift evolution of the mass-metallicity (M-Z) relationship for galaxies, along with a sharp host metallicity cut-off suggested by Modjaz and collaborators, we estimate an upper limit on the stellar mass of a galaxy that can efficiently produce a GRB as a function of redshift. By employing consistent abundance indicators, we find that sub-solar metallicity cut-offs effectively limit GRBs to low stellar mass spirals and dwarf galaxies at low redshift. At higher redshifts, as the average metallicity of galaxies in the Universe falls, the mass range of galaxies capable of hosting a GRB broadens, with an upper bound approaching the mass of even the largest spiral galaxies. We compare these predicted limits to the growing number of published GRB host masses and find that extremely low metallicity cut-offs of 0.1 to 0.5 Z{sub {circle_dot}} are effectively ruled out by a large number of intermediate mass galaxies at low redshift. A mass function that includes a smooth decrease in the efficiency of producing GRBs in galaxies of metallicity above 12+log(O/H){sub KK04} = 8.7 can, however, accommodate a majority of the measured host galaxy masses. We find that at z {approx} 1, the peak in the observed GRB host mass distribution is inconsistent with the expected peak in the mass of galaxies harboring most of the star formation. This suggests that GRBs are metallicity biased tracers of star formation at low and intermediate redshifts, although our model predicts that this bias should disappear at higher redshifts due to the evolving metallicity content of the universe.

  16. The Effect of Host Galaxies on Type Ia Supernovae in the SDSS-II Supernova Survey

    SciTech Connect

    Lampeitl, Hubert; Smith, Mathew; Nichol, Robert C.; Bassett, Bruce; Cinabro, David; Dilday, Benjamin; Foley, Ryan J.; Frieman, Joshua A.; Garnavich, Peter M.; Goobar, Ariel; Im, Myungshin; /Seoul Natl. U. /Rutgers U., Piscataway

    2010-05-01

    We present an analysis of the host galaxy dependencies of Type Ia Supernovae (SNe Ia) from the full three year sample of the SDSS-II Supernova Survey. We re-discover, to high significance, the strong correlation between host galaxy type and the width of the observed SN light curve, i.e., fainter, quickly declining SNe Ia favor passive host galaxies, while brighter, slowly declining Ia's favor star-forming galaxies. We also find evidence (at between 2 to 3{sigma}) that SNe Ia are {approx_equal} 0.1 magnitudes brighter in passive host galaxies, than in star-forming hosts, after the SN Ia light curves have been standardized using the light curve shape and color variations: This difference in brightness is present in both the SALT2 and MCLS2k2 light curve fitting methodologies. We see evidence for differences in the SN Ia color relationship between passive and star-forming host galaxies, e.g., for the MLCS2k2 technique, we see that SNe Ia in passive hosts favor a dust law of R{sub V} {approx_equal} 1, while SNe Ia in star-forming hosts require R{sub V} {approx} 2. The significance of these trends depends on the range of SN colors considered. We demonstrate that these effects can be parameterized using the stellar mass of the host galaxy (with a confidence of > 4{sigma}) and including this extra parameter provides a better statistical fit to our data. Our results suggest that future cosmological analyses of SN Ia samples should include host galaxy information.

  17. Molecular Gas in the Host Galaxies of Long-Duration Gamma-Ray Bursts

    NASA Astrophysics Data System (ADS)

    Hatsukade, B.; Ohta, K.; Kohno, K.; Nakanishi, K.; Tamura, Y.; Endo, A.; Hashimoto, T.

    2016-10-01

    We conducted CO observations in 10 GRB hosts with ALMA and detected in 6 hosts (z = 1-2). We found the hosts have a star-formation efficiency similar to normal star-forming galaxies at z 1-2, suggesting that GRBs occur in normal environments at z 1-2.

  18. Long-Duration Gamma-Ray Burst Host Galaxies in Emission and Absorption

    NASA Astrophysics Data System (ADS)

    Perley, Daniel A.; Niino, Yuu; Tanvir, Nial R.; Vergani, Susanna D.; Fynbo, Johan P. U.

    2016-12-01

    The galaxy population hosting long-duration GRBs provides a means to constrain the progenitor and an opportunity to use these violent explosions to characterize the nature of the high-redshift universe. Studies of GRB host galaxies in emission reveal a population of star-forming galaxies with great diversity, spanning a wide range of masses, metallicities, and redshifts. However, as a population GRB hosts are significantly less massive and poorer in metals than the hosts of other core-collapse transients, suggesting that GRB production is only efficient at metallicities significantly below Solar. GRBs may also prefer compact galaxies, and dense and/or central regions of galaxies, more than other types of core-collapse explosion. Meanwhile, studies of hosts in absorption against the luminous GRB optical afterglow provide a unique means of unveiling properties of the ISM in even the faintest and most distant galaxies; these observations are helping to constrain the chemical evolution of galaxies and the properties of interstellar dust out to very high redshifts. New ground- and space-based instrumentation, and the accumulation of larger and more carefully-selected samples, are continually enhancing our view of the GRB host population.

  19. A Bayesian approach to multi-messenger astronomy: identification of gravitational-wave host galaxies

    SciTech Connect

    Fan, XiLong; Messenger, Christopher; Heng, Ik Siong

    2014-11-01

    We present a general framework for incorporating astrophysical information into Bayesian parameter estimation techniques used by gravitational wave data analysis to facilitate multi-messenger astronomy. Since the progenitors of transient gravitational wave events, such as compact binary coalescences, are likely to be associated with a host galaxy, improvements to the source sky location estimates through the use of host galaxy information are explored. To demonstrate how host galaxy properties can be included, we simulate a population of compact binary coalescences and show that for ∼8.5% of simulations within 200 Mpc, the top 10 most likely galaxies account for a ∼50% of the total probability of hosting a gravitational wave source. The true gravitational wave source host galaxy is in the top 10 galaxy candidates ∼10% of the time. Furthermore, we show that by including host galaxy information, a better estimate of the inclination angle of a compact binary gravitational wave source can be obtained. We also demonstrate the flexibility of our method by incorporating the use of either the B or K band into our analysis.

  20. Continuum Fitting HST QSO Spectra

    NASA Technical Reports Server (NTRS)

    Tytler, David; Oliversen, Ronald J. (Technical Monitor)

    2002-01-01

    The Principal Component Analysis (PCA) method which we are using to fit and describe QSO spectra relies upon the fact that QSO continuum are generally very smooth and simple except for emission and absorption lines. To see this we need high signal-to-noise (S/N) spectra of QSOs at low redshift which have relatively few absorption lines in the Lyman-a forest. We need a large number of such spectra to use as the basis set for the PCA analysis which will find the set of principal component spectra which describe the QSO family as a whole. We have found that too few HST spectra have the required S/N and hence we need to supplement them with ground based spectra of QSOs at higher redshift. We have many such spectra and we have been working to make them suitable for this analysis. We have concentrated on this topic since 12/15/01.

  1. Gamma-ray Bursts: Radio Afterglow and Host Galaxy Study with The FAST Telescope

    NASA Astrophysics Data System (ADS)

    Li, L. B.; Huang, Y. F.; Kong, S. W.; Zhang, Z. B.; Li, D.; Luo, J. J.

    2016-02-01

    For four types of GRBs, namely high-luminosity, low-luminosity, standard and failed GRBs, we calculated their radio afterglow light curves. Meanwhile, considering contributions from host galaxies in radio bands, we statistically investigated the effect of hosts on radio afterglows. It is found that a tight anti-correlation exists between the ratio of radio flux (RRF) of host galaxy to the total radio afterglow peak flux and the observed frequency. Using this method, the host flux densities of those bursts without host measurements can be estimated at low or medium frequencies. We predicted that almost all types of radio afterglows, except that of low-luminosity GRBs, can be observed by FAST up to z = 15 or even more. FAST is expected to significantly expand the samples of GRB radio afterglows and host galaxies.

  2. 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.

  3. A spectral energy distribution analysis of AGN host galaxies in the Chandra-COSMOS Legacy Survey

    NASA Astrophysics Data System (ADS)

    Suh, Hyewon; Civano, Francesca M.; Hasinger, Guenther; Elvis, Martin; Marchesi, Stefano

    2015-01-01

    We present the host galaxy properties of a large sample of ~ 4000 X-ray selected Active Galactic Nuclei (AGN) 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 modeling 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 AGN and a 4-component fitting (nuclear hot dust, AGN big blue bump, galaxy, and starburst components) for unobscured AGN. Galaxy templates are from the stellar population synthesis models of Bruzual & Charlot (2003), nuclear hot dust templates are taken from Silva et al. (2004), and AGN big blue bump templates are from Richards et al. (2006). We use the column density information measured in the X-ray to constrain the AGN 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.

  4. The Host Galaxies of Type Ia Supernovae Discovered by the Palomar Transient Factory

    NASA Technical Reports Server (NTRS)

    Pan, Y.-C.; Sullivan, M.; McGuire, K.; Hook, I. M.; Nugent, P. E.; Howell, D. A.; Arcavi, I.; Botyanszki, J.; Cenko, Stephen Bradley; DeRose, J.

    2013-01-01

    We present spectroscopic observations of the host galaxies of 82 low-redshift type Ia supernovae (SNe Ia) discovered by the Palomar Transient Factory (PTF). We determine star-formation rates, gas-phase stellar metallicities, and stellar masses and ages of these objects. As expected, strong correlations between the SN Ia light-curve width (stretch) and the host age mass metallicity are found: fainter, faster-declining events tend to be hosted by older massive metal-rich galaxies. There is some evidence that redder SNe Ia explode in higher metallicity galaxies, but we found no relation between the SN colour and host galaxy extinction based on the Balmer decrement, suggesting that the colour variation of these SNe does not primarily arise from this source. SNe Ia in higher-mass metallicity galaxies also appear brighter after stretch colour corrections than their counterparts in lower mass hosts, and the stronger correlation is with gas-phase metallicity suggesting this may be the more important variable. We also compared the host stellar mass distribution to that in galaxy targeted SN surveys and the high-redshift untargeted Supernova Legacy Survey (SNLS). SNLS has many more low mass galaxies, while the targeted searches have fewer. This can be explained by an evolution in the galaxy stellar mass function, coupled with a SN delay-time distribution proportional to t1. Finally, we found no significant difference in the mass--metallicity relation of our SN Ia hosts compared to field galaxies, suggesting any metallicity effect on the SN Ia rate is small.

  5. Constraining the nature of the most distant gamma-ray burst host galaxies

    NASA Astrophysics Data System (ADS)

    Basa, S.; Cuby, J. G.; Savaglio, S.; Boissier, S.; Clément, B.; Flores, H.; Le Borgne, D.; Mazure, A.

    2012-06-01

    Aims: Long duration gamma-ray bursts (GRBs) allow us to explore the distant Universe, and are potentially the most effective tracer of the most distant objects. Our current knowledge of the properties of GRB host galaxies at redshifts ≳ 5 is very scarce. We propose to improve this situation by obtaining more observations of high-redshift hosts to better understand their properties and help enable us to use GRBs as probes of the high-redshift universe. Methods: We performed very deep photometric observations of three high-redshift GRB host galaxies, GRB 080913 at z = 6.7, GRB 060927 at z = 5.5 and GRB 060522 at z = 5.1. Our FORS2 and HAWK-I observations at the Very Large Telescope (VLT) targeted the rest-frame ultraviolet continuum of these galaxies, allowing us to constrain their star formation rates (SFRs). In addition, we completed deep spectroscopic observations of the GRB 080913 host galaxy with X-Shooter at the VLT to search for Ly-α emission. For the sake of the discussion, we use published results on another high-redshift GRB host, GRB 050904 at z = 6.3. The sample of GRB host galaxies studied in this paper consists of four out of the five spectroscopically confirmed GRBs at z > 5. Results: Despite our presented observations being the deepest ever reported of high-redshift GRB host galaxies, we do not detect any of the hosts, neither in photometry nor in spectroscopy in the case of GRB 080913. These observations indicate that the GRB host galaxies seem to evolve with time and to have lower SFRs at z > 5 than they have at z ≲ 1. In addition, the host galaxy of GRB 080913 at z = 6.7 does not show Ly-α emission. Conclusions: While the measured properties of the galaxies in our sample agree with the properties of the general galaxy population at z > 5, our observations are not sufficiently sensitive to allow us to infer further conclusions on whether this specific population is representative of the general one. The characterization of high-redshift GRB

  6. Ionised outflows in z ~ 2.4 quasar host galaxies

    NASA Astrophysics Data System (ADS)

    Carniani, S.; Marconi, A.; Maiolino, R.; Balmaverde, B.; Brusa, M.; Cano-Díaz, M.; Cicone, C.; Comastri, A.; Cresci, G.; Fiore, F.; Feruglio, C.; La Franca, F.; Mainieri, V.; Mannucci, F.; Nagao, T.; Netzer, H.; Piconcelli, E.; Risaliti, G.; Schneider, R.; Shemmer, O.

    2015-08-01

    Aims: Outflows driven by active galactic nuclei (AGN) are invoked by galaxy evolutionary models to quench star formation and to explain the origin of the relations observed locally between super-massive black holes and their host galaxies. We here aim to detect extended ionised outflows in luminous quasars, where we expect the highest activity both in star formation and in black-hole accretion. Currently, there are only a few studies based on spatially resolved observations of outflows at high redshift, z > 2. Methods: We analysed a sample of six luminous (L > 1047 erg/s) quasars at z ~ 2.4, observed in H-band using the near-IR integral field spectrometer SINFONI at the VLT. We performed a kinematic analysis of the [Oiii] emission line at λ = 5007 Å. Results: We detect fast, spatially extended outflows in five out of six targets. [Oiii]λ5007 has a complex gas kinematic, with blue-shifted velocities of a few hundreds of km s-1 and line widths up to 1500 km s-1. Using the spectroastrometric method, we infer a size of the ionised outflows of up to ~2 kpc. The properties of the ionised outflows, mass outflow rate, momentum rate, and kinetic power, are correlated with the AGN luminosity. The increase in outflow rate with increasing AGN luminosity is consistent with the idea that a luminous AGN pushes away the surrounding gas through fast outflows that are driven by radiation pressure, which depends on the emitted luminosity. Conclusions: We derive mass outflow rates of about 6-700 M⊙ yr-1 for our sample, which are lower than those observed in molecular outflows. The physical properties of ionised outflows show dependences on AGN luminosity that are similar to those of molecular outflows, but indicate that the mass of ionised gas is lower than that of molecular outflows. Alternatively, this discrepancy between ionised and molecular outflows could be explained with different acceleration mechanisms. Based on Observations collected at the European Organisation for

  7. H0LiCOW. VI. Testing the fidelity of lensed quasar host galaxy reconstruction

    NASA Astrophysics Data System (ADS)

    Ding, Xuheng; Liao, Kai; Treu, Tommaso; Suyu, Sherry H.; Chen, Geoff C.-F.; Auger, Matthew W.; Marshall, Philip J.; Agnello, Adriano; Courbin, Frederic; Nierenberg, Anna M.; Rusu, Cristian E.; Sluse, Dominique; Sonnenfeld, Alessandro; Wong, Kenneth C.

    2017-03-01

    The empirical correlation between the mass of a supermassive black hole (M_BH) and its host galaxy properties is widely considered to be an evidence of their co-evolution. A powerful way to test the co-evolution scenario and learn about the feedback processes linking galaxies and nuclear activity is to measure these correlations as a function of redshift. Unfortunately, currently M_BH can only be estimated in active galaxies at cosmological distances. At these distances, bright active galactic nuclei (AGNs) can outshine the host galaxy, making it extremely difficult to measure the host's luminosity. Strongly lensed AGNs provide in principle a great opportunity to improve the sensitivity and accuracy of the host galaxy luminosity measurements as the host galaxy is magnified and more easily separated from the point source, provided the lens model is sufficiently accurate. In order to measure the M_BH-L correlation with strong lensing, it is necessary to ensure that the lens modelling is accurate, and that the host galaxy luminosity can be recovered to at least a precision and accuracy better than that of the typical M_BH measurement. We carry out extensive and realistic simulations of deep Hubble Space Telescope observations of lensed AGNs obtained by our collaboration. We show that the host galaxy luminosity can be recovered with better accuracy and precision than the typical uncertainty in M_BH(∼0.5 dex) for hosts as faint as 2-4 mag dimmer than the AGN itself. Our simulations will be used to estimate bias and uncertainties in the actual measurements to be presented in a future paper.

  8. DUST-CORRECTED COLORS REVEAL BIMODALITY IN THE HOST-GALAXY COLORS OF ACTIVE GALACTIC NUCLEI AT z {approx} 1

    SciTech Connect

    Cardamone, Carolin N.; Megan Urry, C.; Brammer, Gabriel; Schawinski, Kevin; Treister, Ezequiel; Gawiser, Eric

    2010-09-20

    Using new, highly accurate photometric redshifts from the MUSYC medium-band survey in the Extended Chandra Deep Field-South (ECDF-S), we fit synthetic stellar population models to compare active galactic nucleus (AGN) host galaxies to inactive galaxies at 0.8 {<=} z {<=} 1.2. We find that AGN host galaxies are predominantly massive galaxies on the red sequence and in the green valley of the color-mass diagram. Because both passive and dusty galaxies can appear red in optical colors, we use rest-frame near-infrared colors to separate passively evolving stellar populations from galaxies that are reddened by dust. As with the overall galaxy population, {approx}25% of the 'red' AGN host galaxies and {approx}75% of the 'green' AGN host galaxies have colors consistent with young stellar populations reddened by dust. The dust-corrected rest-frame optical colors are the blue colors of star-forming galaxies, which imply that these AGN hosts are not passively aging to the red sequence. At z {approx} 1, AGN activity is roughly evenly split between two modes of black hole growth: the first in passively evolving host galaxies, which may be heating up the galaxy's gas and preventing future episodes of star formation, and the second in dust-reddened young galaxies, which may be ionizing the galaxy's interstellar medium and shutting down star formation.

  9. Globular cluster systems and their host galaxies: comparison of spatial distributions and colors

    SciTech Connect

    Hargis, Jonathan R.; Rhode, Katherine L.

    2014-11-20

    We present a study of the spatial and color distributions of four early-type galaxies and their globular cluster (GC) systems observed as part of our ongoing wide-field imaging survey. We use BVR KPNO 4 m+MOSAIC imaging data to characterize the galaxies' GC populations, perform surface photometry of the galaxies, and compare the projected two-dimensional shape of the host galaxy light to that of the GC population. The GC systems of the ellipticals NGC 4406 and NGC 5813 both show an elliptical distribution consistent with that of the host galaxy light. Our analysis suggests a similar result for the giant elliptical NGC 4472, but a smaller GC candidate sample precludes a definite conclusion. For the S0 galaxy NGC 4594, the GCs have a circular projected distribution, in contrast to the host galaxy light, which is flattened in the inner regions. For NGC 4406 and NGC 5813, we also examine the projected shapes of the metal-poor and metal-rich GC subpopulations and find that both subpopulations have elliptical shapes that are consistent with those of the host galaxy light. Lastly, we use integrated colors and color profiles to compare the stellar populations of the galaxies to their GC systems. For each galaxy, we explore the possibility of color gradients in the individual metal-rich and metal-poor GC subpopulations. We find statistically significant color gradients in both GC subpopulations of NGC 4594 over the inner ∼5 effective radii (∼20 kpc). We compare our results to scenarios for the formation and evolution of giant galaxies and their GC systems.

  10. Quasar induced galaxy formation: a new paradigm?

    NASA Astrophysics Data System (ADS)

    Elbaz, D.; Jahnke, K.; Pantin, E.; Le Borgne, D.; Letawe, G.

    2009-12-01

    Aims: We discuss observational evidence that quasars play a key role in the formation of galaxies, starting from the detailed study of the quasar HE0450-2958 and extending the discussion to a series of converging evidence that radio jets may trigger galaxy formation. Methods: We use mid infrared imaging with VISIR at the ESO-VLT to model the mid to far infrared energy distribution of the system and the stellar population of the companion galaxy using optical VLT-FORS spectroscopy. The results are combined with optical, CO, radio continuum imaging from ancillary data. Results: The direct detection with VISIR of the 7 kpc distant companion galaxy of HE0450-2958 allows us to spatially separate the sites of quasar and star formation activity in this composite system made of two ultra-luminous infrared galaxies (ULIRGs), where the quasar generates the bulk of the mid infrared light and the companion galaxy powered by star formation dominates in the far infrared. No host galaxy has yet been detected for this quasar, but the companion galaxy stellar mass would bring HE0450-2958 in the local M{BH} - Mstar^bulge relation if it were to merge with the QSO. This is bound to happen because of their close distance (7 kpc) and low relative velocity ( 60-200 km s-1). We conclude that we may be witnessing the building of the M{BH} - Mstar^bulge relation, or at least of a major event in that process. The star formation rate ( 340 M⊙ yr-1), age (40-200 Myr) and stellar mass ( [5-6]×1010 M⊙) are consistent with jet-induced formation of the companion galaxy. We suggest that HE0450-2958 may be fueled by fresh material from cold gas accretion from intergalactic filaments. We map the projected galaxy density surrounding the QSO as a potential tracer of intergalactic filaments and discuss a putative detection. Comparison to other systems suggest that an inside-out formation of quasar host galaxies and jet-induced galaxy formation may be a common process. Two tests are proposed for

  11. Improving Type Ia Supernova Standard Candle Cosmology Measurements Using Observations of Early-Type Host Galaxies

    NASA Astrophysics Data System (ADS)

    Meyers, Joshua Evan

    Type Ia supernovae (SNe Ia) are the current standard-bearers for dark energy but face several hurdles for their continued success in future large surveys. For example, spectroscopic classification of the myriad SNe soon to be discovered will not be possible, and systematics from uncertainties in dust corrections and the evolution of SN demographics and/or empirical calibrations used to standardize SNe Ia must be studied. Through the identification of low-dust host galaxies and through increased understanding of both the SN - progenitor connections and empirical calibrations, host galaxy information may offer opportunities to improve the cosmological utility of SNe Ia. The first half of this thesis analyzes the sample of SNe Ia discovered by the Hubble Space Telescope (HST) Cluster Supernova Survey augmented with HST-observed SNe Ia in the Great Observatories Origins Deep Survey (GOODS) fields. Correlations between properties of SNe and their host galaxies are examined at high redshift. Using galaxy color and quantitative morphology to determine the red sequence in 25 clusters, a model is developed to distinguish passively evolving early-type galaxies from star-forming galaxies in both clusters and the field. With this approach, 6 early-type cluster member hosts and 11 SN Ia early-type field hosts are identified. For the first time at z > 0.9, the correlation between host galaxy type and the rise and fall time of SN Ia light curves is confirmed. The relatively simple spectral energy distributions of early-type galaxies also enables stellar mass measurements for these hosts. In combination with literature host mass measurements, these measurements are used to show, at z > 0.9, a hint of the correlation between host mass and Hubble residuals reported at lower redshift. By simultaneously fitting cluster galaxy formation histories and dust content to the scatter of the cluster red sequences, it is shown that dust reddening of early-type cluster SN hosts is likely less

  12. The Coevolution of Nuclear Star Clusters, Massive Black Holes, and Their Host Galaxies

    NASA Astrophysics Data System (ADS)

    Antonini, Fabio; Barausse, Enrico; Silk, Joseph

    2015-10-01

    Studying how nuclear star clusters (NSCs) form and how they are related to the growth of the central massive black holes (MBHs) and their host galaxies is fundamental for our understanding of the evolution of galaxies and the processes that have shaped their central structures. We present the results of a semi-analytical galaxy formation model that follows the evolution of dark matter halos along merger trees, as well as that of the baryonic components. This model allows us to study the evolution of NSCs in a cosmological context, by taking into account the growth of NSCs due to both dynamical-friction-driven migration of stellar clusters and star formation triggered by infalling gas, while also accounting for dynamical heating from (binary) MBHs. We find that in situ star formation contributes a significant fraction (up to ∼80%) of the total mass of NSCs in our model. Both NSC growth through in situ star formation and that through star cluster migration are found to generate NSC—host galaxy scaling correlations that are shallower than the same correlations for MBHs. We explore the role of galaxy mergers on the evolution of NSCs and show that observational data on NSC—host galaxy scaling relations provide evidence of partial erosion of NSCs by MBH binaries in luminous galaxies. We show that this observational feature is reproduced by our models, and we make predictions about the NSC and MBH occupation fraction in galaxies. We conclude by discussing several implications for theories of NSC formation.

  13. STAR CLUSTER COMPLEXES AND THE HOST GALAXY IN THREE H II GALAXIES: Mrk 36, UM 408, AND UM 461

    SciTech Connect

    Lagos, P.; Telles, E.; Nigoche-Netro, A.

    2011-11-15

    We present a stellar population study of three H II galaxies (Mrk 36, UM 408, and UM 461) based on the analysis of new ground-based high-resolution near-infrared J, H, and K{sub p} broadband and Br{gamma} narrowband images obtained with Gemini/NIRI. We identify and determine the relative ages and masses of the elementary star clusters and/or star cluster complexes of the starburst regions in each of these galaxies by comparing the colors with evolutionary synthesis models that include the contribution of stellar continuum, nebular continuum, and emission lines. We found that the current star cluster formation efficiency in our sample of low-luminosity H II galaxies is {approx}10%. Therefore, most of the recent star formation is not in massive clusters. Our findings seem to indicate that the star formation mode in our sample of galaxies is clumpy, and that these complexes are formed by a few massive star clusters with masses {approx}>10{sup 4} M{sub Sun }. The age distribution of these star cluster complexes shows that the current burst started recently and likely simultaneously over short timescales in their host galaxies, triggered by some internal mechanism. Finally, the fraction of the total cluster mass with respect to the low surface brightness (or host galaxy) mass, considering our complete range in ages, is less than 1%.

  14. Broad Absorption Line Quasars and Galaxy Evolution

    NASA Astrophysics Data System (ADS)

    Wills, B. J.

    2009-12-01

    Luminous QSOs are signposts to galaxy evolution. Local supermassive black holes are the faded relics of quasars in their heyday at redshifts ˜2. Relationships between the masses of these local supermassive black holes and their host galaxy bulges reveal an intimate link, fundamental to galaxy evolution: the newly evolving galaxy fuels the seed black hole through its accretion disk and by loss of angular momentum and energy in the form of outflowing winds. As the central engine approaches Eddington luminosities, winds drive away dusty gas, revealing a luminous QSO and halting star formation in the galaxy bulge. Relativistic winds are manifested in powerful radio jets in ˜10% of quasars, and sub-relativistic winds are revealed by broad blueshifted absorption troughs in the “broad absorption line” (BAL) quasars. Historically, BALs avoid powerful radio quasars. Here we examine the BALs to investigate this inverse connection.

  15. Supernovae and their host galaxies - II. The relative frequencies of supernovae types in spirals

    NASA Astrophysics Data System (ADS)

    Hakobyan, A. A.; Nazaryan, T. A.; Adibekyan, V. Zh.; Petrosian, A. R.; Aramyan, L. S.; Kunth, D.; Mamon, G. A.; de Lapparent, V.; Bertin, E.; Gomes, J. M.; Turatto, M.

    2014-11-01

    We present an analysis of the relative frequencies of different supernova (SN) types in spirals with various morphologies and in barred or unbarred galaxies. We use a well-defined and homogeneous sample of spiral host galaxies of 692 SNe from the Sloan Digital Sky Survey in different stages of galaxy-galaxy interaction and activity classes of nucleus. We propose that the underlying mechanisms shaping the number ratios of SNe types can be interpreted within the framework of interaction-induced star formation, in addition to the known relations between morphologies and stellar populations. We find a strong trend in behaviour of the NIa/NCC ratio depending on host morphology, such that early spirals include more Type Ia SNe. The NIbc/NII ratio is higher in a broad bin of early-type hosts. The NIa/NCC ratio is nearly constant when changing from normal, perturbed to interacting galaxies, then declines in merging galaxies, whereas it jumps to the highest value in post-merging/remnant galaxies. In contrast, the NIbc/NII ratio jumps to the highest value in merging galaxies and slightly declines in post-merging/remnant subsample. The interpretation is that the star formation rates and morphologies of galaxies, which are strongly affected in the final stages of interaction, have an impact on the number ratios of SNe types. The NIa/NCC (NIbc/NII) ratio increases (decreases) from star-forming to active galactic nuclei (AGN) classes of galaxies. These variations are consistent with the scenario of an interaction-triggered starburst evolving into AGN during the later stages of interaction, accompanied with the change of star formation and transformation of the galaxy morphology into an earlier type.

  16. Massive star-forming host galaxies of quasars on Sloan digital sky survey stripe 82

    SciTech Connect

    Matsuoka, Yoshiki; Strauss, Michael A.; Price, Ted N. III; DiDonato, Matthew S.

    2014-01-10

    The stellar properties of about 800 galaxies hosting optically luminous, unobscured quasars at z < 0.6 are analyzed. Deep co-added Sloan Digital Sky Survey (SDSS) images of the quasars on Stripe 82 are decomposed into nucleus and host galaxy using point spread function and Sérsic models. The systematic errors in the measured galaxy absolute magnitudes and colors are estimated to be less than 0.5 mag and 0.1 mag, respectively, with simulated quasar images. The effect of quasar light scattered by the interstellar medium is also carefully addressed. The measured quasar-to-galaxy ratio in total flux decreases toward longer wavelengths, from ∼8 in the u band to ∼1 in the i and z bands. We find that the SDSS quasars are hosted exclusively by massive galaxies (stellar mass M {sub star} > 10{sup 10} M {sub ☉}), which is consistent with previous results for less luminous narrow-line (obscured) active galactic nuclei (AGNs). The quasar hosts are very blue and almost absent on the red sequence, showing stark contrast to the color-magnitude distribution of normal galaxies. The fact that more powerful AGNs reside in galaxies with higher star-formation efficiency may indicate that negative AGN feedback, if it exists, is not concurrent with the most luminous phase of AGNs. We also find positive correlation between the mass of supermassive black holes (SMBHs; M {sub BH}) and host stellar mass, but the M {sub BH}-M {sub star} relation is offset toward large M {sub BH} or small M {sub star} compared to the local relation. While this could indicate that SMBHs grow earlier than do their host galaxies, such an argument is not conclusive, as the effect may be dominated by observational biases.

  17. Hubble Residuals of Nearby SN Ia Are Correlated with Host Galaxy Masses

    SciTech Connect

    Kelly, Patrick L.; Hicken, Malcolm; Burke, David L.; Mandel, Kaisey S.; Kirshner, Robert P.; /Harvard-Smithsonian Ctr. Astrophys.

    2010-05-03

    From Sloan Digital Sky Survey u{prime} g{prime} r{prime} i{prime} z{prime} imaging, we estimate the stellar masses of the host galaxies of 70 low redshift SN Ia (0.015 < z < 0.08) from the hosts absolute luminosities and mass-to-light ratios. These nearby SN were discovered largely by searches targeting luminous galaxies, and we find that their host galaxies are substantially more massive than the hosts of SN discovered by the flux-limited Supernova Legacy Survey. Testing four separate light curve fitters, we detect {approx}2.5{sigma} correlations of Hubble residuals with both host galaxy size and stellar mass, such that SN Ia occurring in physically larger, more massive hosts are {approx}10% brighter after light curve correction. The Hubble residual is the deviation of the inferred distance modulus to the SN, calculated from its apparent luminosity and light curve properties, away from the expected value at the SN redshift. Marginalizing over linear trends in Hubble residuals with light curve parameters shows that the correlations cannot be attributed to a light curve-dependent calibration error. Combining 180 higher-redshift ESSENCE, SNLS, and HigherZ SN with 30 nearby SN whose host masses are less than 10{sup 10.8} M{circle_dot} n a cosmology fit yields 1 + w = 0.22{sub -0.108}{sup +0.152}, while a combination where the 30 nearby SN instead have host masses greater than 10{sup 10.8} M{circle_dot} yields 1 + w = ?0.03{sub -0.143}{sup +0.217}. Progenitor metallicity, stellar population age, and dust extinction correlate with galaxy mass and may be responsible for these systematic effects. Host galaxy measurements will yield improved distances to SN Ia.

  18. AGN host galaxy mass function in COSMOS. Is AGN feedback responsible for the mass-quenching of galaxies?

    NASA Astrophysics Data System (ADS)

    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.

    2016-04-01

    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 AGN 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 model 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 AGN cosmic downsizing as observed in the AGN 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 AGN host galaxies to star-forming galaxies is basically constant (~10%). Finally, the comparison of the AGN HGMF for different luminosity and specific accretion rate subclasses with a previously published phenomenological model prediction for the "transient" population, which are galaxies in the process of being mass-quenched, reveals that low-luminosity AGN 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 AGN (log Lbol ≳ 46 [erg/s]) may be responsible for the quenching of star formation in the host galaxy.

  19. Bulgeless Galaxies Hosting 107 M⊙ AGN in Galaxy Zoo: The Growth of Black Holes via Secular Processes

    NASA Astrophysics Data System (ADS)

    Simmons, Brooke; Lintott, C. J.; Schawinski, K.; Moran, E. C.; Han, A.; Kaviraj, S.; Masters, K. L.; Urry, C. M.; Willett, K.; Bamford, S. P.; Nichol, R.

    2013-01-01

    The growth of supermassive black holes (SMBHs) appears to proceed via multiple pathways including mergers and secular processes, but these are difficult to disentangle for most galaxies given their complex evolutionary histories. In order to understand the effects of secular galaxy evolution on black hole growth, we require a sample of active galactic nuclei (AGN) in galaxies with a calm formation history free of significant mergers, a population that heretofore has been difficult to locate. Here we present a sample of 13 AGN in massive galaxies lacking the classical bulges believed inevitably to result from mergers; they also either lack or have extremely small pseudobulges, meaning they have had very calm accretion histories. This is the largest sample to date of massive, bulgeless AGN host galaxies selected without any direct restriction on the SMBH mass. The broad-line objects in the sample have black hole masses of 106-7 M⊙ Eddington arguments imply similar masses for the rest of the sample, meaning these black holes have grown substantially in the absence of mergers or other bulge-building processes such as violent disk instabilities. The black hole masses are systematically higher than expected from established bulge-black hole relations. However, these systems may be consistent with the correlation between black hole mass and total stellar mass. We discuss these results in the context of other studies and consider the implication that the details of stellar galaxy evolution and dynamics may not be fundamental to the co-evolution of galaxies and black holes.

  20. Do Typical Galaxies in Adolescence Already Host Growing Black Holes?

    NASA Astrophysics Data System (ADS)

    Trump, Jonathan

    2012-10-01

    This archival grism proposal achieves a 100-fold gain in high-quality {5+sigma} information for discovering which properties of adolescent {0.7galaxies of typical mass and SFR are linked to AGN activity. We propose to analyze 147 WFC3 G141 and 111 ACS 800L pointings of 2-orbit grism data in the CANDELS fields, for a sample of 3000 galaxies reaching SFR 5 Msun/yr and stellar masses of log{M*/Msun} 9 at z 1.5. We will leverage spatially-resolved line ratios to uniquely distinguish a nuclear AGN from extended low-metallicity or shocked gas. Compared to our 30-galaxy published sample that hints at AGNs in low-mass z 2 galaxies {Trump et al. 2011}, this 3000 galaxy sample enables a 100-fold gain in divisions by galaxy morphology, SFR, and stellar mass to discover which galaxy properties correlate most with rapid SMBH growth. We will stack the deep {0.8-4 Ms} Chandra data available in these fields as an independent check of the grism AGN/SF diagnostics. The unique ancillary data in these fields also include ACS+WFC3 imaging for morphologies, deep multiwavelength data for well-sampled SEDs and stellar masses, and previous optical {and future near-IR} spectroscopy to supplement the G141 coverage. Based on discussions with the GOODS-N and 3D-HST teams, our proposed AGN science does not overlap with their proposed or funded science goals. As a value-added product for the community we will release, via the public Rainbow-CANDELS database server, an atlas of spatial maps of emission lines and line ratios {and associated errors} for the entire sample of 3000 galaxies.

  1. The Co-evolution of QSOs and Galaxies

    NASA Astrophysics Data System (ADS)

    Coziol, R.; Torres-Papaqui, J. P.; Andernach, H.

    2015-07-01

    Using two large samples of QSOs detected in the mid-infrared (MIR) with WISE, we find that the change of W2-W3 colors with redshift suggests that star formation in their host galaxies increases by a factor of 3 from z = 0 to 2.7, then stays constant up to z = 4, and decreases above z=4. This behavior is slightly different from the best fits for the star formation history of field galaxies as deduced from the Optical-UV and IR, but is consistent with what is observed for sub-mm galaxies at high z. Our results constitute the clearest evidence, so far, that QSO host galaxies form their stars before field galaxies, and are in good agreement with the hierarchical biased structure formation paradigm.

  2. Scaling Relations Between Warm Galactic Outflows and Their Host Galaxies

    NASA Astrophysics Data System (ADS)

    Chisholm, John; Tremonti, Christy A.; Leitherer, Claus; Chen, Yanmei; Wofford, Aida; Lundgren, Britt

    2015-10-01

    We report on a sample of 48 nearby, star-forming galaxies observed with the Cosmic Origin Spectrograph on the Hubble Space Telescope. We measure the kinematics of warm gas in galactic outflows using a combination of four Si ii absorption lines. We use multi-wavelength ancillary data to estimate stellar masses (M*), star formation rates (SFR), circular velocities (vcirc), and morphologies. The galaxies cover four orders of magnitude in M* and SFR, and sample a wide range of morphologies from starbursting mergers to normal star-forming galaxies. We derive 3.0-3.5σ relations between outflow velocity and SFR, M*, and vcirc. The outflow velocities scale as SFR0.08-0.22, {M}*0.12-0.20 and {v}{circ}0.44-0.87, with the range depending on whether we use a maximum or a central velocity to quantify the outflow velocity. After accounting for their increased SFR, mergers drive 32% faster outflows than non-merging galaxies, with all of the highest velocity outflows arising from mergers. Low-mass galaxies (log(M*/ M⊙) < 10.5) lose some low-ionization gas through galactic outflows, while more massive galaxies retain all of their low-ionization gas, unless they undergo a merger.

  3. The Relation between Luminous AGNs and Star Formation in Their Host Galaxies

    NASA Astrophysics Data System (ADS)

    Xu, Lei; Rieke, G. H.; Egami, E.; Haines, C. P.; Pereira, M. J.; Smith, G. P.

    2015-08-01

    We study the relation of active galactic nuclei (AGNs) to star formation in their host galaxies. Our sample includes 205 Type-1 and 85 Type-2 AGNs, 162 detected with Herschel, from fields surrounding 30 galaxy clusters in the Local Cluster Substructure Survey. The sample is identified by optical line widths and ratios after selection to be brighter than 1 mJy at 24 μm. We show that Type-2 AGN [O iii]λ5007 line fluxes at high z can be contaminated by their host galaxies with typical spectrograph entrance apertures (but our sample is not compromised in this way). We use spectral energy distribution (SED) templates to decompose the galaxy SEDs and estimate star formation rates (SFRs), AGN luminosities, and host galaxy stellar masses (described in an accompanying paper). The AGNs arise from massive black holes (˜ 3× {10}8{M}⊙ ) accreting at ˜10% of the Eddington rate and residing in galaxies with stellar mass \\gt 3× {10}10{M}⊙ ; those detected with Herschel have IR luminosity from star formation in the range of {L}{SF,{IR}}˜ {10}10-{10}12{L}⊙ . We find that (1) the specific SFRs in the host galaxies are generally consistent with those of normal star-forming (main sequence) galaxies; (2) there is a strong correlation between the luminosities from star formation and the AGN; and (3) the correlation may not result from a causal connection, but could arise because the black hole mass (and hence AGN Eddington luminosity) and star formation are both correlated with the galaxy mass.

  4. Do Nuclear Star Clusters and Supermassive Black Holes Follow the Same Host-Galaxy Correlations?

    DOE PAGES

    Erwin, Peter; Gadotti, Dimitri Alexei

    2012-01-01

    Smore » tudies have suggested that there is a strong correlation between the masses of nuclear star clusters (NSCs) and their host galaxies, a correlation which is said to be an extension of the well-known correlations between supermassive black holes (SMBHs) and their host galaxies. But careful analysis of disk galaxies—including 2D bulge/disk/bar decompositions—shows that whileMBHs correlate with the stellar mass of the bulge component of galaxies, the masses of NSCs correlate much better with the total galaxy stellar mass. In addition, the mass ratio M NSC / M ⋆ ,  tot for NSCs in spirals (at least those with Hubble typesc and later) is typically an order of magnitude smaller than the mass ratio M BH / M ⋆ ,  bul ofMBHs. The absence of a universal “central massive object” correlation argues against common formation and growth mechanisms for bothMBHs and NSCs. We also discuss evidence for a break in the NSC-host galaxy correlation, galaxies with Hubble types earlier thanbc appear to host systematically more massive NSCs than do typesc and later.« less

  5. A statistical study of H i gas in nearby narrow-line AGN-hosting galaxies

    SciTech Connect

    Zhu, Yi-Nan; Wu, Hong E-mail: hwu@bao.ac.cn

    2015-01-01

    As a quenching mechanism, active galactic nucleus (AGN) feedback could suppress on going star formation in host galaxies. On the basis of a sample of galaxies selected from the Arecibo Legacy Fast ALFA (ALFALFA) H i survey, the dependence of the H i mass (M{sub H} {sub i}), stellar mass (M{sub *}), and H i-to-stellar mass ratio (M{sub H} {sub i}/M{sub *}) on various tracers of AGN activity are presented and analyzed in this paper. Almost all the AGN hostings in this sample are gas-rich galaxies, and there is not any evidence to indicate that the AGN activity could increase or decrease either M{sub H} {sub i} or M{sub H} {sub i}/M{sub *}. The position of the cold neutral gas cannot be fixed accurately based only on available H i data, due to the large beam size of ALFALFA survey. In addition, even though AGN hostings are more easily detected by an H i survey compared with absorption line galaxies, these two types of galaxies show similar star formation history. If an AGN hosting would ultimately evolve into an old red galaxy with low cold gas, then when and how the gas has been exhausted must be solved by future hypotheses and observations.

  6. Radio Loudness of AGNs: Host Galaxy Morphology and the Spin Paradigm

    SciTech Connect

    Stawarz, L.; Sikora, M.; Lasota, J.-P.

    2007-10-15

    We investigate how the total radio luminosity of AGN-powered radio sources depends on their accretion luminosity and the central black hole mass. We find that AGNs form two distinct and well separated sequences on the radio-loudness -- Eddington-ratio plane. We argue that these sequences mark the real upper bounds of radio-loudness of two distinct populations of AGNs: those hosted respectively by elliptical and disk galaxies. Both sequences show the same dependence of the radio-loudness on the Eddington ratio (an increase with decreasing Eddington ratio), which suggests that another parameter in addition to the accretion rate must play a role in determining the jet production efficiency in active galactic nuclei, and that this parameter is related to properties of the host galaxy. The revealed host-related radio dichotomy breaks down at high accretion rates where the dominant fraction of luminous quasars hosted by elliptical galaxies is radio quiet. We argue that the huge difference between the radio-loudness reachable by AGNs in disc and elliptical galaxies can be explained by the scenario according to which the spin of a black hole determines the outflows power, and central black holes can reach large spins only in early type galaxies (following major mergers), and not (in a statistical sense) in spiral galaxies.

  7. Energy input from quasars regulates the growth and activity of black holes and their host galaxies.

    PubMed

    Di Matteo, Tiziana; Springel, Volker; Hernquist, Lars

    2005-02-10

    In the early Universe, while galaxies were still forming, black holes as massive as a billion solar masses powered quasars. Supermassive black holes are found at the centres of most galaxies today, where their masses are related to the velocity dispersions of stars in their host galaxies and hence to the mass of the central bulge of the galaxy. This suggests a link between the growth of the black holes and their host galaxies, which has indeed been assumed for a number of years. But the origin of the observed relation between black hole mass and stellar velocity dispersion, and its connection with the evolution of galaxies, have remained unclear. Here we report simulations that simultaneously follow star formation and the growth of black holes during galaxy-galaxy collisions. We find that, in addition to generating a burst of star formation, a merger leads to strong inflows that feed gas to the supermassive black hole and thereby power the quasar. The energy released by the quasar expels enough gas to quench both star formation and further black hole growth. This determines the lifetime of the quasar phase (approaching 100 million years) and explains the relationship between the black hole mass and the stellar velocity dispersion.

  8. Interstellar Mg II and C IV absorption toward Markarian 205 by NGC 4319 - An 'optically thick' QSO absorption system

    NASA Technical Reports Server (NTRS)

    Bowen, David V.; Blades, J. C.

    1993-01-01

    We have used the Goddard High-Resolution Spectrograph aboard HST to detect interstellar Mg II and C IV absorption lines toward Mrk 205, a QSO whose sightline passes within 3/h kpc of the foreground galaxy NGC 4319. Absorption is detected from both local Milky Way gas and from NGC 4319, making this the first observation of an isolated, low-redshift galaxy causing an 'optically thick' QSO absorption system. We also observed for the first time Mg II absorption from two local High Velocity Clouds along this same sightline. The data support the premise that metal absorption lines seen at higher redshift in QSO spectra originate in gas associated with intervening galaxies. However, neither the strong absorption by (half) of our own Galaxy, nor the weak absorption by NGC 4319, may be typical of absorbers in general.

  9. Supernovae and their host galaxies - IV. The distribution of supernovae relative to spiral arms

    NASA Astrophysics Data System (ADS)

    Aramyan, L. S.; Hakobyan, A. A.; Petrosian, A. R.; de Lapparent, V.; Bertin, E.; Mamon, G. A.; Kunth, D.; Nazaryan, T. A.; Adibekyan, V.; Turatto, M.

    2016-07-01

    Using a sample of 215 supernovae (SNe), we analyse their positions relative to the spiral arms of their host galaxies, distinguishing grand-design (GD) spirals from non-GD (NGD) galaxies. We find that: (1) in GD galaxies, an offset exists between the positions of Ia and core-collapse (CC) SNe relative to the peaks of arms, while in NGD galaxies the positions show no such shifts; (2) in GD galaxies, the positions of CC SNe relative to the peaks of arms are correlated with the radial distance from the galaxy nucleus. Inside (outside) the corotation radius, CC SNe are found closer to the inner (outer) edge. No such correlation is observed for SNe in NGD galaxies nor for SNe Ia in either galaxy class; (3) in GD galaxies, SNe Ibc occur closer to the leading edges of the arms than do SNe II, while in NGD galaxies they are more concentrated towards the peaks of arms. In both samples of hosts, the distributions of SNe Ia relative to the arms have broader wings. These observations suggest that shocks in spiral arms of GD galaxies trigger star formation in the leading edges of arms affecting the distributions of CC SNe (known to have short-lived progenitors). The closer locations of SNe Ibc versus SNe II relative to the leading edges of the arms supports the belief that SNe Ibc have more massive progenitors. SNe Ia having less massive and older progenitors, have more time to drift away from the leading edge of the spiral arms.

  10. HUBBLE SPACE TELESCOPE Imaging of the Host Galaxies of High-RedshiftRadio-loud Quasars

    NASA Astrophysics Data System (ADS)

    Lehnert, Matthew D.; van Breugel, Wil J. M.; Heckman, Timothy M.; Miley, George K.

    1999-09-01

    We present rest-frame UV and Lyα images of spatially resolved structures (``hosts'') around five high-redshift radio-loud quasars obtained with the WFPC2 camera on the Hubble Space Telescope (HST). The quasars were imaged with the PC1 through the F555W (``V''-band) filter, which at the redshifts of the quasars (2.1host galaxies that appeared to have properties similar to those of high-redshift radio galaxies. Our HST observations allow a more detailed investigation of quasar host morphologies and a comparison with similar HST studies of radio galaxies by others. Using several methods to measure and quantify the host properties we find that all five quasars are extended and that this ``fuzz'' contains ~5%-40% of the total continuum flux and 15%-65% of the Lyα flux within a radius of about 1.5". The rest-frame UV luminosities of the hosts are log λPλ~11.9-12.5 Lsolar (assuming no internal dust extinction), comparable to the luminous radio galaxies at similar redshifts and a factor 10 higher than both radio-quiet field galaxies at z~2-3 and the most UV-luminous low-redshift starburst galaxies. The Lyα luminosities of the hosts are log LLyα~44.3-44.9 ergs s-1, which are also similar to the those of luminous high-redshift radio galaxies and considerably larger than the Lyα luminosities of high-redshift field galaxies. To generate the Lyα luminosities of the hosts would require roughly a few percent of the total observed ionizing luminosity of the quasar. The UV continuum morphologies of the hosts appear complex and knotty at the relatively high surface brightness levels of our exposures (about 24 V mag arcsec-2). In two quasars we find evidence for foreground galaxies that confuse the

  11. Supermassive black holes: Coevolution (or not) of black holes and host galaxies

    NASA Astrophysics Data System (ADS)

    Kormendy, John

    2013-07-01

    Supermassive black holes (BHs) have been found in 75 galaxies by observing spatially resolved dynamics. The Hubble Space Telescope (HST) revolutionized BH work by advancing the subject from its `proof of concept' phase into quantitative studies of BH demographics. Most influential was the discovery of a tight correlation between BH masses M • and the velocity dispersions σ of stars in the host galaxy bulge components at radii where the stars mostly feel each other and not the BH. Together with correlations between M • and bulge luminosity, with the `missing light' that defines galaxy cores, and with numbers of globular clusters, this has led to the conclusion that BHs and bulges coevolve by regulating each other's growth. This simple picture with one set of correlations for all galaxies dominated BH work in the past decade. New results are now replacing the above, simple story with a richer and more plausible picture in which BHs correlate differently with different kinds of galaxy components. BHs with masses of 105-106 M ⊙ live in some bulgeless galaxies. So classical (merger-built) bulges are not necessary equipment for BH formation. On the other hand, while they live in galaxy disks, BHs do not correlate with galaxy disks or with disk-grown pseudobulges. They also have no special correlation with dark matter halos beyond the fact that halo gravity controls galaxy formation. This leads to the suggestion that there are two modes of BH feeding, (1) local, secular and episodic feeding of small BHs in largely bulgeless galaxies that involves too little energy feedback to drive BH-host-galaxy coevolution and (2) global feeding in major galaxy mergers that rapidly grows giant BHs in short-duration events whose energy feedback does affect galaxy formation. After these quasar-like phases, maintenance-mode BH feedback into hot, X-ray-emitting gas continues to have a primarily negative effect in preventing late-time star formation when cold gas or gas-rich galaxies

  12. Supermassive black holes and central star clusters: Connection with the host galaxy kinematics and color

    NASA Astrophysics Data System (ADS)

    Zasov, A. V.; Cherepashchuk, A. M.

    2013-11-01

    The relationship between the masses of the central, supermassive black holes ( M bh) and of the nuclear star clusters ( M nc) of disk galaxies with various parameters galaxies are considered: the rotational velocity at R = 2 kpc V (2), the maximum rotational velocity V max, the indicative dynamical mass M 25, the integrated mass of the stellar population M *, and the integrated color index B-V. The rotational velocities andmasses of the central objects were taken from the literature. Themass M nc correlatesmore closely with the kinematic parameters and the disk mass than M bh, including with the velocity V max, which is closely related to the virial mass of the dark halo. On average, lenticular galaxies are characterized by higher masses M bh compared to other types of galaxies with similar characteristics. The dependence of the blackhole mass on the color index is bimodal: galaxies of the red group (red-sequence) with B-V >0.6-0.7 which are mostly early-type galaxies with weak star formation, differ appreciably from blue galaxies, which have higher values of M nc and M bh. At the dependences we consider between the masses of the central objects and the parameters of the host galaxies (except for the dependence of M bh on the central velocity dispersion), the red-group galaxies have systematically higher M bh values, even when the host-galaxy parameters are similar. In contrast, in the case of nuclear star clusters, the blue and red galaxies form unified sequences. The results agree with scenarios in which most red-group galaxies form as a result of the partial or complete loss of interstellar gas in a stage of high nuclear activity in galaxies whose central black-hole masses exceed 106-107 M ⊙ (depending on the mass of the galaxy itself). The bulk of disk galaxies with M bh > 107 M ⊙ are lenticular galaxies (types S0, E/S0) whose disks are practically devoid of gas.

  13. Molecular gas in the host galaxy of a quasar at redshift z = 6.42.

    PubMed

    Walter, Fabian; Bertoldi, Frank; Carilli, Chris; Cox, Pierre; Lo, K Y; Neri, Roberto; Fan, Xiaohui; Omont, Alain; Strauss, Michael A; Menten, Karl M

    2003-07-24

    Observations of molecular hydrogen in quasar host galaxies at high redshifts provide fundamental constraints on galaxy evolution, because it is out of this molecular gas that stars form. Molecular hydrogen is traced by emission from the carbon monoxide molecule, CO; cold H2 itself is generally not observable. Carbon monoxide has been detected in about ten quasar host galaxies with redshifts z > 2; the record-holder is at z = 4.69 (refs 1-3). Here we report CO emission from the quasar SDSS J114816.64 + 525150.3 (refs 5, 6) at z = 6.42. At that redshift, the Universe was only 1/16 of its present age, and the era of cosmic reionization was just ending. The presence of about 2 x 1010 M\\circ of H2 in an object at this time demonstrates that molecular gas enriched with heavy elements can be generated rapidly in the youngest galaxies.

  14. CEPHEID VARIABLES IN THE MASER-HOST GALAXY NGC 4258

    SciTech Connect

    Hoffmann, Samantha L.; Macri, Lucas M.

    2015-06-15

    We present results of a ground-based survey for Cepheid variables in NGC 4258. This galaxy plays a key role in the Extragalactic Distance Scale due to its very precise and accurate distance determination via very long baseline interferometry observations of water masers. We imaged two fields within this galaxy using the Gemini North telescope and the Gemini Multi-Object Spectrograph, obtaining 16 epochs of data in the Sloan Digital Sky Survey gri bands over 4 yr. We carried out point-spread function photometry and detected 94 Cepheids with periods between 7 and 127 days, as well as an additional 215 variables which may be Cepheids or Population II pulsators. We used the Cepheid sample to test the absolute calibration of theoretical gri Period–Luminosity relations and found good agreement with the maser distance to this galaxy. The expected data products from the Large Synoptic Survey Telescope should enable Cepheid searches out to at least 10 Mpc.

  15. The Galaxy Hosts And Large-Scale Environments of Short-Hard Gamma-Ray Bursts

    SciTech Connect

    Prochaska, Jason X.; Bloom, J.S.; Chen, H.-W.; Foley, R.J.; Perley, D.A.; Ramirez-Ruiz, E.; Granot, J.; Lee, W.H.; Pooley, D.; Alatalo, K.; Hurley, K.; Cooper, M.C.; Dupree, A.K.; Gerke, B.F.; Hansen, B.M.S.; Kalirai, J.S.; Newman, J.A.; Rich, R.M.; Richer, H.; Stanford, S.A.; Stern, D.; /Lick Observ. /UC, Berkeley, Astron. Dept. /Chicago U., Astron. Astrophys. Ctr. /Princeton, Inst. Advanced Study /KIPAC, Menlo Park /UNAM, Inst. Astron. /UC, Berkeley, Space Sci. Dept. /Harvard-Smithsonian Ctr. Astrophys. /UC, Berkeley /UCLA /LBL, Berkeley /British Columbia U. /UC, Davis /LLNL, Livermore /Caltech, JPL

    2005-10-07

    The rapid succession of discovery of short-duration hard-spectrum GRBs has led to unprecedented insights into the energetics of the explosion and nature of the progenitors. Yet short of the detection of a smoking gun, like a burst of coincident gravitational radiation or a Li-Paczynski mini-supernova, it is unlikely that a definitive claim can be made for the progenitors. As was the case with long-duration soft-spectrum GRBs, however, the expectation is that a systematic study of the hosts and the locations of short GRBs could begin to yield fundamental clues about their nature. We present the first aggregate study of the host galaxies of short-duration hard-spectrum GRBs. In particular, we present the Gemini-North and Keck discovery spectra of the galaxies that hosted three short GRBs and a moderate-resolution (R {approx} 6000) spectrum of a fourth host. We find that these short-hard GRBs originate in a variety of low-redshift (z < 1) environments that differ substantially from those of long-soft GRBs, both on individual galaxy scales and on galaxy-cluster scales. Specifically, three of the bursts are found to be associated with old and massive galaxies with no current (< 0.1M{sub {circle_dot}} yr{sup -1}) or recent star formation. Two of these galaxies are located within a cluster environment. These observations support an origin from the merger of compact stellar remnants, such as double neutron stars of a neutron star-black hole binary. The fourth event, in contrast, occurred within a dwarf galaxy with a star formation rate exceeding 0.5 M{sub {circle_dot}} yr{sup -1}. Therefore, it appears that like supernovae of Type Ia, the progenitors of short-hard bursts are created in all galaxy types, suggesting a corresponding class with a wide distribution of delay times between formation and explosion.

  16. The Black Hole-Bulge Mass Relation in Megamaser Host Galaxies

    NASA Astrophysics Data System (ADS)

    Läsker, Ronald; Greene, Jenny E.; Seth, Anil; van de Ven, Glenn; Braatz, James A.; Henkel, Christian; Lo, K. Y.

    2016-07-01

    We present Hubble Space Telescope (HST) images for nine megamaser disk galaxies with the primary goal of studying photometric BH-galaxy scaling relations. The megamaser disks provide the highest-precision extragalactic BH mass measurements, while our high-resolution HST imaging affords us the opportunity to decompose the complex nuclei of their late-type hosts in detail. Based on the morphologies and shapes of the galaxy nuclei, we argue that most of these galaxies’ central regions contain secularly evolving components (pseudo-bulges), and in many cases we photometrically identify co-existing “classical” bulge components as well. Using these decompositions, we draw the following conclusions. (1) The megamaser BH masses span two orders of magnitude (106-{10}8 {M}⊙ ) while the stellar mass of their spiral host galaxies are all ˜ {10}11 {M}⊙ within a factor of three. (2) The BH masses at a given bulge mass or total stellar mass in the megamaser host spiral galaxies tend to be lower than expected when compared to an extrapolation of the BH-bulge relation based on early-type galaxies. (3) The observed large intrinsic scatter of BH masses in the megamaser host galaxies raises the question of whether scaling relations exist in spiral galaxies. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program 12185.

  17. Radio constraints on heavily obscured star formation within dark gamma-ray burst host galaxies

    SciTech Connect

    Perley, D. A.; Perley, R. A.

    2013-12-01

    Highly dust-obscured starbursting galaxies (submillimeter galaxies and their ilk) represent the most extreme sites of star formation in the distant universe and contribute significantly to overall cosmic star formation beyond z > 1.5. Some stars formed in these environments may also explode as gamma-ray bursts (GRBs) and contribute to the population of 'dark' bursts. Here we present Very Large Array wideband radio-continuum observations of 15 heavily dust-obscured Swift GRBs to search for radio synchrotron emission associated with intense star formation in their host galaxies. Most of these targets (11) are not detected. Of the remaining four objects, one detection is marginal, and for two others we cannot yet rule out the contribution of a long-lived radio afterglow. The final detection is secure, but indicates a star formation rate (SFR) roughly consistent with the dust-corrected UV-inferred value. Most galaxies hosting obscured GRBs are therefore not forming stars at extreme rates, and the amount of optical extinction seen along a GRB afterglow sightline does not clearly correlate with the likelihood that the host has a sufficiently high SFR to be radio-detectable. While some submillimeter galaxies do readily produce GRBs, these GRBs are often not heavily obscured—suggesting that the outer (modestly obscured) parts of these galaxies overproduce GRBs and the inner (heavily obscured) parts underproduce GRBs relative to their respective contributions to star formation, hinting at strong chemical or initial mass function gradients within these systems.

  18. The galaxy hosts and large-scale environments of short-hard (gamma)-ray bursts

    SciTech Connect

    Prochaska, J X; Bloom, J S; Chen, H; Foley, R J; Perley, D A; Ramirez-Ruiz, E; Granot, J; Lee, W H; Pooley, D; Alatalo, K; Hurley, K; Cooper, M C; Dupree, A K; Gerke, B F; Hansen, B S; Kalirai, J S; Newman, J A; Rich, R M; Richer, H; Stanford, S A; Stern, D; van Breugel, W

    2006-04-07

    The nature of the progenitors of short duration, hard spectrum, gamma-ray bursts (GRBs) has remained a mystery. Even with the recent localizations of four short-hard GRBs, no transient emission has been found at long wavelengths that directly constrains the progenitor nature. Instead, as was the case in studying the different morphological subclasses of supernovae and the progenitors of long-duration GRBs, we suggest that the progenitors of short bursts can be meaningfully constrained by the environment in which the bursts occur. Here we present the discovery spectra of the galaxies that hosted three short-hard GRBs and the spectrum of a fourth host. The results indicate that these environments, both at the galaxy scale and galaxy-cluster scale, differ substantially from those of long-soft GRBs. The spatial offset of three bursts from old and massive galaxy hosts strongly favors an origin from the merger of compact stellar remnants, such as double neutron stars or a neutron-star black hole binary. The star-forming host of another GRB provides confirmation that, like supernovae of Type Ia, the progenitors of short-hard bursts are created in all galaxy types. This indicates a class of progenitors with a wide distribution of delay times between formation and explosion.

  19. The nuclear properties and extended morphologies of powerful radio galaxies: the roles of host galaxy and environment

    NASA Astrophysics Data System (ADS)

    Miraghaei, H.; Best, P. N.

    2017-01-01

    Powerful radio galaxies exist as either compact or extended sources, with the extended sources traditionally classified by their radio morphologies as Fanaroff-Riley (FR) type I and II sources. FRI/II and compact radio galaxies have also been classified by their optical spectra into two different types: high excitation (HERG; quasar-mode) and low excitation (LERG; jet-mode). We present a catalogue of visual morphologies for a complete sample of >1000 1.4-GHz-selected extended radio sources from the Sloan Digital Sky Survey. We study the environment and host galaxy properties of FRI/II and compact sources, classified into HERG/LERG types, in order to separate and distinguish the factors that drive the radio morphological variations from those responsible for the spectral properties. Comparing FRI LERGs with FRII LERGs at fixed stellar mass and radio luminosity, we show that FRIs typically reside in richer environments and are hosted by smaller galaxies with higher mass surface density; this is consistent with extrinsic effects of jet disruption driving the FR dichotomy. Using matched samples of HERGs and LERGs, we show that HERG host galaxies are more frequently star-forming, with more evidence for disk-like structure than LERGs, in accordance with currently-favoured models of fundamentally different fuelling mechanisms. Comparing FRI/II LERGs with compact LERGs, we find the primary difference is that compact objects typically harbour less massive black holes. This suggests that lower-mass black holes may be less efficient at launching stable radio jets, or do so for shorter times. Finally, we investigate rarer sub-classes: wide-angle tail, head-tail, FR-hybrid and double-double sources.

  20. Tracing the evolution of active galactic nuclei host galaxies over the last 9 Gyr of cosmic time

    SciTech Connect

    Goulding, A. D.; Forman, W. R.; Jones, C.; Murray, S. S.; Paggi, A.; Ashby, M. L. N.; Huang, J.-S.; Kraft, R.; Willner, S. P.; Hickox, R. C.; Coil, A. L.; Cooper, M. C.; Newman, J. A.; Weiner, B. J.

    2014-03-01

    We present the results of a combined galaxy population analysis for the host galaxies of active galactic nuclei (AGN) identified at 0 < z < 1.4 within the Sloan Digital Sky Survey, Boötes, and DEEP2 surveys. We identified AGN in a uniform and unbiased manner at X-ray, infrared, and radio wavelengths. Supermassive black holes undergoing radiatively efficient accretion (detected as X-ray and/or infrared AGN) appear to be hosted in a separate and distinct galaxy population than AGN undergoing powerful mechanically dominated accretion (radio AGN). Consistent with some previous studies, radiatively efficient AGN appear to be preferentially hosted in modest star-forming galaxies, with little dependence on AGN or galaxy luminosity. AGN exhibiting radio-emitting jets due to mechanically dominated accretion are almost exclusively observed in massive, passive galaxies. Crucially, we now provide strong evidence that the observed host-galaxy trends are independent of redshift. In particular, these different accretion-mode AGN have remained as separate galaxy populations throughout the last 9 Gyr. Furthermore, it appears that galaxies hosting AGN have evolved along the same path as galaxies that are not hosting AGN with little evidence for distinctly separate evolution.

  1. THE COEVOLUTION OF NUCLEAR STAR CLUSTERS, MASSIVE BLACK HOLES, AND THEIR HOST GALAXIES

    SciTech Connect

    Antonini, Fabio; Barausse, Enrico; Silk, Joseph

    2015-10-10

    Studying how nuclear star clusters (NSCs) form and how they are related to the growth of the central massive black holes (MBHs) and their host galaxies is fundamental for our understanding of the evolution of galaxies and the processes that have shaped their central structures. We present the results of a semi-analytical galaxy formation model that follows the evolution of dark matter halos along merger trees, as well as that of the baryonic components. This model allows us to study the evolution of NSCs in a cosmological context, by taking into account the growth of NSCs due to both dynamical-friction-driven migration of stellar clusters and star formation triggered by infalling gas, while also accounting for dynamical heating from (binary) MBHs. We find that in situ star formation contributes a significant fraction (up to ∼80%) of the total mass of NSCs in our model. Both NSC growth through in situ star formation and that through star cluster migration are found to generate NSC—host galaxy scaling correlations that are shallower than the same correlations for MBHs. We explore the role of galaxy mergers on the evolution of NSCs and show that observational data on NSC—host galaxy scaling relations provide evidence of partial erosion of NSCs by MBH binaries in luminous galaxies. We show that this observational feature is reproduced by our models, and we make predictions about the NSC and MBH occupation fraction in galaxies. We conclude by discussing several implications for theories of NSC formation.

  2. The Spitzer/Swift Gamma-Ray Burst Host Galaxy Legacy Survey

    NASA Astrophysics Data System (ADS)

    Perley, Daniel; Berger, Edo; Butler, Nathaniel; Cenko, S. Bradley; Chary, Ranga-Ram; Cucchiara, Antonino; Ellis, Richard; Fong, Wen-fai; Fruchter, Andrew; Fynbo, Johan; Gehrels, Neil; Graham, John; Greiner, Jochen; Hjorth, Jens; Hunt, Leslie; Jakobsson, Pall; Kruehler, Thomas; Laskar, Tanmoy; Le Floc'h, Emerich; Levan, Andrew; Levesque, Emily; Littlejohns, Owen; Malesani, Daniele; Michalowski, Michal; Milvang-Jensen, Bo; Prochaska, J. Xavier; Salvaterra, Ruben; Schulze, Steve; Schady, Patricia; Tanvir, Nial; de Ugarte Postigo, Antonio; Vergani, Susanna; Watson, Darach

    2016-08-01

    Long-duration gamma-ray bursts act as beacons to the sites of star-formation in the distant universe. GRBs reveal galaxies too faint and star-forming regions too dusty to characterize in detail using any other method, and provide a powerful independent constraint on the evolution of the cosmic star-formation rate density at high-redshift. However, a full understanding of the GRB phenomenon and its relation to cosmic star-formation requires connecting the observations obtained from GRBs to the properties of the galaxies hosting them. The large majority of GRBs originate at moderate to high redshift (z>1) and Spitzer has proven crucial for understanding the host population, given its unique ability to observe the rest-frame NIR and its unrivaled sensitivity and efficiency. We propose to complete a comprehensive public legacy survey of the Swift GRB host population to build on our earlier successes and push beyond the statistical limits of previous, smaller efforts. Our survey will enable a diverse range of GRB and galaxy science including: (1) to quantitatively and robustly map the connection between GRBs and cosmic star-formation to constrain the GRB progenitor and calibrate GRB rate-based measurements of the high-z cosmic star-formation rate; (2) to constrain the luminosity function of star-forming galaxies at the faint end and at high redshift; (3) to understand how the ISM properties seen in absorption in high-redshift galaxies unveiled by GRBs - metallicity, dust column, dust properties - connect to global properties of the host galaxies such as mass and age. Building on a decade of experience at both observatories, our observations will create an enduring joint Swift-Spitzer legacy sample - providing the definitive resource with which to examine all aspects of the GRB/galaxy connection for years to come and setting the stage for intensive JWST follow-up of the most interesting sources from our sample.

  3. Detection of Three Gamma-ray Burst Host Galaxies at z ˜ 6

    NASA Astrophysics Data System (ADS)

    McGuire, J. T. W.; Tanvir, N. R.; Levan, A. J.; Trenti, M.; Stanway, E. R.; Shull, J. M.; Wiersema, K.; Perley, D. A.; Starling, R. L. C.; Bremer, M.; Stocke, J. T.; Hjorth, J.; Rhoads, J. E.; Curtis-Lake, E.; Schulze, S.; Levesque, E. M.; Robertson, B.; Fynbo, J. P. U.; Ellis, R. S.; Fruchter, A. S.

    2016-07-01

    Long-duration gamma-ray bursts (GRBs) allow us to pinpoint and study star-forming galaxies in the early universe, thanks to their orders of magnitude brighter peak luminosities compared to other astrophysical sources, and their association with the deaths of massive stars. We present Hubble Space Telescope Wide Field Camera 3 detections of three Swift GRB host galaxies lying at redshifts z = 5.913 (GRB 130606A), z = 6.295 (GRB 050904), and z = 6.327 (GRB 140515A) in the F140W (wide-JH band, {λ }{{obs}}˜ 1.4 μ {{m}}) filter. The hosts have magnitudes (corrected for Galactic extinction) of {m}{λ {obs},{AB}}={26.34}-0.16+0.14,{27.56}-0.22+0.18, and {28.30}-0.33+0.25, respectively. In all three cases, the probability of chance coincidence of lower redshift galaxies is ≲ 2 % , indicating that the detected galaxies are most likely the GRB hosts. These are the first detections of high-redshift (z\\gt 5) GRB host galaxies in emission. The galaxies have luminosities in the range 0.1-0.6 {L}z=6* (with {M}1600* =-20.95+/- 0.12) and half-light radii in the range 0.6-0.9 {{kpc}}. Both their half-light radii and luminosities are consistent with existing samples of Lyman-break galaxies at z˜ 6. Spectroscopic analysis of the GRB afterglows indicate low metallicities ([{{M/H}}]≲ -1) and low dust extinction ({A}{{V}}≲ 0.1) along the line of sight. Using stellar population synthesis models, we explore the implications of each galaxy’s luminosity for its possible star-formation history and consider the potential for emission line metallicity determination with the upcoming James Webb Space Telescope.

  4. Spectroscopic Properties of Star-Forming Host Galaxies and Type Ia Supernova Hubble Residuals in a Nearly Unbiased Sample

    SciTech Connect

    D'Andrea, Chris B.; et al.

    2011-12-20

    We examine the correlation between supernova host galaxy properties and their residuals on the Hubble diagram. We use supernovae discovered during the Sloan Digital Sky Survey II - Supernova Survey, and focus on objects at a redshift of z < 0.15, where the selection effects of the survey are known to yield a complete Type Ia supernova sample. To minimize the bias in our analysis with respect to measured host-galaxy properties, spectra were obtained for nearly all hosts, spanning a range in magnitude of -23 < M_r < -17. In contrast to previous works that use photometric estimates of host mass as a proxy for global metallicity, we analyze host-galaxy spectra to obtain gas-phase metallicities and star-formation rates from host galaxies with active star formation. From a final sample of ~ 40 emission-line galaxies, we find that light-curve corrected Type Ia supernovae are ~ 0.1 magnitudes brighter in high-metallicity hosts than in low-metallicity hosts. We also find a significant (> 3{\\sigma}) correlation between the Hubble residuals of Type Ia supernovae and the specific star-formation rate of the host galaxy. We comment on the importance of supernova/host-galaxy correlations as a source of systematic bias in future deep supernova surveys.

  5. SPECTROSCOPIC PROPERTIES OF STAR-FORMING HOST GALAXIES AND TYPE Ia SUPERNOVA HUBBLE RESIDUALS IN A NEARLY UNBIASED SAMPLE

    SciTech Connect

    D'Andrea, Chris B.; Gupta, Ravi R.; Sako, Masao; Morris, Matt; Nichol, Robert C.; Campbell, Heather; Lampeitl, Hubert; Brown, Peter J.; Olmstead, Matthew D.; Frieman, Joshua A.; Kessler, Richard; Garnavich, Peter; Jha, Saurabh W.; Marriner, John; Schneider, Donald P.; Smith, Mathew

    2011-12-20

    We examine the correlation between supernova (SN) host-galaxy properties and their residuals in the Hubble diagram. We use SNe discovered during the Sloan Digital Sky Survey-II Supernova Survey, and focus on objects at a redshift of z < 0.15, where the selection effects of the survey are known to yield a complete Type Ia supernova (SN Ia) sample. To minimize the bias in our analysis with respect to measured host-galaxy properties, spectra were obtained for nearly all hosts, spanning a range in magnitude of -23 < M{sub r} < -17. In contrast to previous works that use photometric estimates of host mass as a proxy for global metallicity, we analyze host-galaxy spectra to obtain gas-phase metallicities and star formation rates (SFRs) from host galaxies with active star formation. From a final sample of {approx}40 emission-line galaxies, we find that light-curve-corrected SNe Ia are {approx}0.1 mag brighter in high-metallicity hosts than in low-metallicity hosts. We also find a significant (>3{sigma}) correlation between the Hubble Residuals of SNe Ia and the specific SFR of the host galaxy. We comment on the importance of SN/host-galaxy correlations as a source of systematic bias in future deep SN surveys.

  6. The black hole-host galaxy relation for very low mass quasars

    NASA Astrophysics Data System (ADS)

    Sanghvi, J.; Kotilainen, J. K.; Falomo, R.; Decarli, R.; Karhunen, K.; Uslenghi, M.

    2014-12-01

    Recently, the relation between the masses of the black hole (MBH) and the host galaxy (Mhost) in quasars has been probed down to the parameter space of MBH ˜ 108 M⊙ and Mhost ˜ 1011 M⊙ at z < 0.5. In this study, we have investigated the MBH-Mhost log-linear relation for a sample of 37 quasars with low black hole masses (107 M⊙ < MBH < 108.3 M⊙) at 0.5 < z < 1.0. The black hole masses were derived using virial mass estimates from Sloan Digital Sky Survey (SDSS) optical spectra. For 25 quasars, we detected the presence of the host galaxy from deep near-infrared H-band imaging, whereas upper limits for the host galaxy luminosity (mass) were estimated for the 12 unresolved quasars. We combined our previous studies with the results from this work to create a sample of 89 quasars at z < 1.0 having a large range of black hole masses (107 M⊙ < MBH < 1010 M⊙) and host galaxy masses (1010 M⊙ < Mhost < 1013 M⊙). Most of the quasars at the low-mass end lie below the extrapolation of the local relation. This apparent break in the linearity of the entire sample is due to increasing fraction of disc-dominated host galaxies in the low-mass quasars. After correcting for the disc component, and considering only the bulge component, the bilinear regression for the entire quasar sample holds over 3.5 dex in both the black hole mass and the bulge mass, and is in very good agreement with the local relation. We advocate secular evolution of discs of galaxies being responsible for the relatively strong disc domination.

  7. Sub-millimeter emission from type Ia supernova host galaxies at z=0.5

    NASA Astrophysics Data System (ADS)

    Clements, D. L.; Farrah, D.; Fox, M.; Rowan-Robinson, M.; Afonso, J.

    2004-05-01

    We present deep sub-millimetre (sub-mm) observations of sixteen galaxies at z=0.5, selected through being hosts of a type Ia supernova. Two galaxies are detected directly, and the sample, excluding the brightest detected galaxy, is detected statistically with a mean 850 μm flux of 0.92 ± 0.33 mJy. We infer that the mean value of AV in normal galaxies is 0-80% higher than locally, in agreement with galaxy chemical evolution models. The dust in the brightest sub-mm object in our sample is best interpreted as normal `cirrus' dust similar to that seen locally. This result, when combined with local surveys of type Ia supernovae, suggests that dust in supernova host galaxies at z=0.5 could produce a dimming that is comparable to the dimming attributed to accelerated expansion. This emphasizes the need to carefully monitor dust extinction when using type Ia supernovae to measure the cosmological parameters. As supernova surveys push to higher redshifts and to greater precision in extracted cosmological parameters, understanding the role of dust in these objects will become even more important.

  8. Accreting SMBH in the COSMOS field: the connection to their host galaxies .

    NASA Astrophysics Data System (ADS)

    Merloni, A.; Bongiorno, A.

    Using the rich multi-band photometry in the COSMOS field we explore the host galaxy properties of a large, complete, sample of X-ray and spectroscopically selected AGN. Based on a two-components fit to their Spectral Energy Distribution (SED) we derive rest-frame magnitudes, colours, stellar masses and star formation rates up to z˜ 3. The probability for a galaxy to host a black hole growing at any given specific accretion rate (the ratio of X-ray luminosity to the host stellar mass) is independent of the galaxy mass and follows a power-law distribution in L_X/M. By looking at the normalisation of such a probability distribution, we show how the incidence of AGN increases with redshift as rapidly as (1+z)4.2, in close resemblance with the overall evolution of the specific star formation rate. Although AGN activity and star formation appear to have a common triggering mechanism, we do not find any 'smoking gun' signalling powerful AGN influence on the global properties of their host galaxies.

  9. VizieR Online Data Catalog: Long & short GRBs with host galaxies data (Li+, 2016)

    NASA Astrophysics Data System (ADS)

    Li, Y.; Zhang, B.; Lu, H.-J.

    2017-01-01

    Our main sample includes 375 GRBs with spectroscopic redshift measurements in the literature before 2014 June 30. Also included are 32 GRBs with host galaxy information, even though no spectroscopic redshifts have been reported for these bursts. Altogether we have 407 GRBs. (5 data files).

  10. The metallicity and dust content of a redshift 5 gamma-ray burst host galaxy

    SciTech Connect

    Sparre, M.; Krühler, T.; Fynbo, J. P. U.; Watson, D. J.; De Ugarte Postigo, A.; Hjorth, J.; Malesani, D.; Hartoog, O. E.; Kaper, L.; Wiersema, K.; D'Elia, V.; Afonso, P. M. J.; Covino, S.; Flores, H.; Goldoni, P.; Jakobsson, P.; Klose, S.; Levan, A. J.; and others

    2014-04-20

    Observations of the afterglows of long gamma-ray bursts (GRBs) allow the study of star-forming galaxies across most of cosmic history. Here we present observations of GRB 111008A, from which we can measure metallicity, chemical abundance patterns, dust-to-metals ratio (DTM), and extinction of the GRB host galaxy at z = 5.0. The host absorption system is a damped Lyα absorber with a very large neutral hydrogen column density of log N(H I)/cm{sup −2}=22.30±0.06 and a metallicity of [S/H] = –1.70 ± 0.10. It is the highest-redshift GRB with such a precise metallicity measurement. The presence of fine-structure lines confirms the z = 5.0 system as the GRB host galaxy and makes this the highest redshift where Fe II fine-structure lines have been detected. The afterglow is mildly reddened with A{sub V} = 0.11 ± 0.04 mag, and the host galaxy has a DTM that is consistent with being equal to or lower than typical values in the Local Group.

  11. ASASSN-17di: Discovery of A Probable Supernova in an Uncatalogued Host Galaxy

    NASA Astrophysics Data System (ADS)

    Brimacombe, J.; Post, R. S.; Brown, J. S.; Stanek, K. Z.; Holoien, T. W.-S.; Kochanek, C. S.; Shields, J.; Thompson, T. A.; Shappee, B. J.; Prieto, J. L.; Bersier, D.; Dong, Subo; Bose, S.; Chen, Ping; Cruz, I.; Fernandez, J. M.; Koff, R. A.; Stone, G.

    2017-03-01

    During the ongoing All Sky Automated Survey for SuperNovae (ASAS-SN, Shappee et al. 2014), using data from the quadruple 14-cm "Cassius" telescope in Cerro Tololo, Chile, we discovered a new transient source, most likely a supernova, in an uncatalogued host galaxy.

  12. Kinematics and host-galaxy properties suggest a nuclear origin for calcium-rich supernova progenitors

    NASA Astrophysics Data System (ADS)

    Foley, Ryan J.

    2015-09-01

    Calcium-rich supernovae (Ca-rich SNe) are peculiar low-luminosity SNe Ib with relatively strong Ca spectral lines at ˜2 months after peak brightness. This class also has an extended projected offset distribution, with several members of the class offset from their host galaxies by 30-150 kpc. There is no indication of any stellar population at the SN positions. Using a sample of 13 Ca-rich SNe, we present kinematic evidence that the progenitors of Ca-rich SNe originate near the centres of their host galaxies and are kicked to the locations of the SN explosions. Specifically, SNe with small projected offsets have large line-of-sight velocity shifts as determined by nebular lines, while those with large projected offsets have no significant velocity shifts. Therefore, the velocity shifts must not be primarily the result of the SN explosion. Additionally, nearly every Ca-rich SN is hosted by a galaxy with indications of a recent merger and/or is in a dense environment. We propose a progenitor model which fits all current data: the progenitor system for a Ca-rich SN is a double white dwarf (WD) system where at least one WD has a significant He abundance. This system, through an interaction with a super-massive black hole (SMBH) is ejected from its host galaxy and the binary is hardened, significantly reducing the merger time. After 10-100 Myr (on average), the system explodes with a large physical offset. The rate for such events is significantly enhanced for galaxies which have undergone recent mergers, potentially making Ca-rich SNe new probes of both the galaxy merger rate and (binary) SMBH population.

  13. A COMPACT GROUP OF GALAXIES AT Z = 2.48 HOSTING AN AGN-DRIVEN OUTFLOW

    SciTech Connect

    Shih, Hsin-Yi; Stockton, Alan E-mail: stockton@ifa.hawaii.edu

    2015-12-10

    We present observations of a remarkable compact group of galaxies at z = 2.48. Four galaxies, all within 40 kpc of each other, surround a powerful high-redshift radio source. This group comprises two compact red passive galaxies and a pair of merging galaxies. One of the red galaxies, with an apparent stellar mass of 3.6 × 10{sup 11}M{sub ⊙} and an effective radius of 470 pc, is one of the most extreme examples of a massive quiescent compact galaxy found so far. One of the pair of merging galaxies hosts the active galactic nucleus (AGN) producing the large powerful radio structure. The merger is massive and enriched, consistent with the mass–metallicity relation expected at this redshift. Close to the merging nuclei, the emission lines exhibit broad and asymmetric profiles that suggest outflows powered either by a very young expanding radio jet or by AGN radiation. At ≳50 kpc from the system, we found a fainter extended-emission region that may be a part of a radio-jet-driven outflow.

  14. Imaging Polarimetry of Scattered Light from the Buried QSO in IRAS F15307+3252

    NASA Astrophysics Data System (ADS)

    Gerber, Jeffrey; Hines, D. C.

    2013-01-01

    We present new imaging polarimetry observations of the Hyperluminous Infrared Galaxy and Type 2 QSO IRAS F15307+3252 (z = 0.9257). The observations were obtained with the High-Resolution Camera (HRC) of the Advance Camera for Surveys (ACS) aboard the Hubble Space Telescope (HST). The images show strongly polarized (p ≥ 20%) light extending ~8 kpc southwest from the center of the galaxy. The overall shape suggests that the extended emission has a single-sided, conical structure of apparent half-opening angle ~16 degrees and apex centered at the galaxy nucleus. The polarization position angle (at each resolution element) is perpendicular to the axis of the extended emission, implying that the structure is illuminated by a central source in the galaxy nucleus that is not seen directly. F15307+3252 is known to harbor a buried QSO that was revealed in a polarized spectrum by Hines et al. (1995); the degree of polarization and position angle of this polarized spectrum match those of the extended structure seen in our new HST/ACS data. We thus conclude that this extended emission is light from the buried QSO that is scattered (thus polarized) into our line of sight, and importantly, this object would be classified optically as a Type 1 QSO if viewed from the vantage point of the scattering material. The conical structure of the scattered light suggests that the material blocking our direct line of sight to the QSO has a spatial distribution similar to the dusty torus in lower redshift Active Galactic Nuclei (AGNs). Assuming that the scattered-light-cone half-opening angle is the same as the dusty torus half-opening angle, we derive a dust-covering fraction of ≥ 95%. This, and comparison between the observed spectral energy distribution of F15307+3252 and that of a composite Type 1 QSO, suggests that the majority of the luminosity in F15307+3252 is powered by the central QSO. Deep HST/ACS images in total light also show clearly that F15307+3252 sits at the center of a

  15. Which haloes host Herschel-ATLAS galaxies in the local Universe?

    NASA Astrophysics Data System (ADS)

    Guo, Qi; Cole, Shaun; Lacey, Cedric G.; Baugh, Carlton M.; Frenk, Carlos S.; Norberg, Peder; Auld, R.; Baldry, I. K.; Bamford, S. P.; Bourne, N.; Buttiglione, E. S.; Cava, A.; Cooray, A.; Croom, S.; Dariush, A.; de Zotti, G.; Driver, S.; Dunne, L.; Dye, S.; Eales, S.; Fritz, J.; Hopkins, A.; Hopwood, R.; Ibar, E.; Ivison, R. J.; Jarvis, M.; Jones, D. H.; Kelvin, L.; Liske, J.; Loveday, J.; Maddox, S. J.; Parkinson, H.; Pascale, E.; Peacock, J. A.; Pohlen, M.; Prescott, M.; Rigby, E. E.; Robotham, A.; Rodighiero, G.; Sharp, R.; Smith, D. J. B.; Temi, P.; van Kampen, E.

    2011-04-01

    We measure the projected cross-correlation between low-redshift (z < 0.5) far-infrared selected galaxies in the science demonstration phase (SDP) field of the Herschel-ATLAS (H-ATLAS) survey and optically selected galaxies from the Galaxy and Mass Assembly (GAMA) redshift survey. In order to obtain robust correlation functions, we restrict the analysis to a subset of 969 out of 6900 H-ATLAS galaxies, which have reliable optical counterparts with r < 19.4 mag and well-determined spectroscopic redshifts. The overlap region between the two surveys is 12.6 deg2; the matched sample has a median redshift of z≈ 0.2. The cross-correlation of GAMA and H-ATLAS galaxies within this region can be fitted by a power law, with correlation length r0≈ 4.63 ± 0.51 Mpc. Comparing with the corresponding autocorrelation function of GAMA galaxies within the SDP field yields a relative bias (averaged over 2-8 Mpc) of H-ATLAS and GAMA galaxies of bH/bG≈ 0.6. Combined with clustering measurements from previous optical studies, this indicates that most of the low-redshift H-ATLAS sources are hosted by haloes with masses comparable to that of the Milky Way. The correlation function appears to depend on the 250-μm luminosity, L250, with bright (median luminosity νL250˜ 1.6 × 1010 L⊙) objects being somewhat more strongly clustered than faint (νL250˜ 4.0 × 109 L⊙) objects. This implies that galaxies with higher dust-obscured star formation rates are hosted by more massive haloes.

  16. Far-infrared observations of an unbiased sample of gamma-ray burst host galaxies

    NASA Astrophysics Data System (ADS)

    Kohn, S. A.; Michałowski, M. J.; Bourne, N.; Baes, M.; Fritz, J.; Cooray, A.; De Looze, I.; De Zotti, G.; Dannerbauer, H.; Dunne, L.; Dye, S.; Eales, S.; Furlanetto, C.; Gonzalez-Nuevo, J.; Ibar, E.; Ivison, R. J.; Maddox, S. J.; Scott, D.; Smith, D. J. B.; Smith, M. W. L.; Symeonidis, M.; Valiante, E.

    2015-04-01

    Gamma-ray bursts (GRBs) are the most energetic phenomena in the Universe; believed to result from the collapse and subsequent explosion of massive stars. Even though it has profound consequences for our understanding of their nature and selection biases, little is known about the dust properties of the galaxies hosting GRBs. We present analysis of the far-infrared properties of an unbiased sample of 20 BeppoSAX and Swift GRB host galaxies (at an average redshift of z = 3.1) located in the Herschel Astrophysical Terahertz Large Area Survey, the Herschel Virgo Cluster Survey, the Herschel Fornax Cluster Survey, the Herschel Stripe 82 Survey and the Herschel Multi-tiered Extragalactic Survey, totalling 880 deg2, or ˜3 per cent of the sky in total. Our sample selection is serendipitous, based only on whether the X-ray position of a GRB lies within a large-scale Herschel survey - therefore our sample can be considered completely unbiased. Using deep data at wavelengths of 100-500 μm, we tentatively detected 1 out of 20 GRB hosts located in these fields. We constrain their dust masses and star formation rates (SFRs), and discuss these in the context of recent measurements of submillimetre galaxies and ultraluminous infrared galaxies. The average far-infrared flux of our sample gives an upper limit on SFR of <114 M⊙ yr-1. The detection rate of GRB hosts is consistent with that predicted assuming that GRBs trace the cosmic SFR density in an unbiased way, i.e. that the fraction of GRB hosts with SFR > 500 M⊙ yr-1 is consistent with the contribution of such luminous galaxies to the cosmic star formation density.

  17. The Host Galaxy and Redshift of the Repeating Fast Radio Burst FRB 121102

    NASA Astrophysics Data System (ADS)

    Tendulkar, S. P.; Bassa, C. G.; Cordes, J. M.; Bower, G. C.; Law, C. J.; Chatterjee, S.; Adams, E. A. K.; Bogdanov, S.; Burke-Spolaor, S.; Butler, B. J.; Demorest, P.; Hessels, J. W. T.; Kaspi, V. M.; Lazio, T. J. W.; Maddox, N.; Marcote, B.; McLaughlin, M. A.; Paragi, Z.; Ransom, S. M.; Scholz, P.; Seymour, A.; Spitler, L. G.; van Langevelde, H. J.; Wharton, R. S.

    2017-01-01

    The precise localization of the repeating fast radio burst (FRB 121102) has provided the first unambiguous association (chance coincidence probability p ≲ 3 × 10‑4) of an FRB with an optical and persistent radio counterpart. We report on optical imaging and spectroscopy of the counterpart and find that it is an extended (0.″6–0.″8) object displaying prominent Balmer and [O iii] emission lines. Based on the spectrum and emission line ratios, we classify the counterpart as a low-metallicity, star-forming, mr‧ = 25.1 AB mag dwarf galaxy at a redshift of z = 0.19273(8), corresponding to a luminosity distance of 972 Mpc. From the angular size, the redshift, and luminosity, we estimate the host galaxy to have a diameter ≲4 kpc and a stellar mass of M* ∼ (4–7) × 107 M⊙, assuming a mass-to-light ratio between 2 to 3 M⊙ L⊙‑1. Based on the Hα flux, we estimate the star formation rate of the host to be 0.4 M⊙ yr‑1 and a substantial host dispersion measure (DM) depth ≲324 pc cm‑3. The net DM contribution of the host galaxy to FRB 121102 is likely to be lower than this value depending on geometrical factors. We show that the persistent radio source at FRB 121102’s location reported by Marcote et al. is offset from the galaxy’s center of light by ∼200 mas and the host galaxy does not show optical signatures for AGN activity. If FRB 121102 is typical of the wider FRB population and if future interferometric localizations preferentially find them in dwarf galaxies with low metallicities and prominent emission lines, they would share such a preference with long gamma-ray bursts and superluminous supernovae.

  18. X-Ray Spectrum of a Narrow-Line QSO

    NASA Technical Reports Server (NTRS)

    Halpern, Jules P.

    1998-01-01

    During the reporting period, seven papers using ASCA data, supported in whole or in part by this grant, were published or submitted to refereed journals. Their abstracts are given in this report, and the complete bibliographic references are listed in the Appendix. Titles include (1) A Broad-Band X-ray Study of the Geminga Pulsar; (2) ASCA Observations of PSR 1920+10 and PSR 0950+08; (3) X-ray and Optical Spectroscopy of IRAS 20181-2244: Not a Type 2 QSO, but a I Zw I Object; (4) Models for X-ray Emission from Isolated Pulsars; (5) Optical and X-ray Spectroscopy of 1E 0449.4-1823: Demise of the Original Type 2 QSO; (6) The ASCA Spectrum of the Broad-Line Radio Galaxy Pictor A: A Simple Power Law with No Fe Ka Line; and (7) ASCA Spectra of NGC 4388 and ESO 103-G35: Absorption, Reflection, and Variability in Intermediate Type Seyfert Galaxies.

  19. The Dependence of Cluster Galaxy Properties on the Central Entropy of their Host Cluster

    NASA Astrophysics Data System (ADS)

    Kim, Jae-Woo; Ko, Jongwan; Hwang, Ho Seong; Edge, Alastair C.; Lee, Joon Hyeop; Lee, Jong Chul; Jeong, Hyunjin

    2017-02-01

    We present a study of the connection between brightest cluster galaxies (BCGs) and their host galaxy clusters. Using galaxy clusters at 0.1< z< 0.3 from the Hectospec Cluster Survey (HeCS) with X-ray information from the Archive of Chandra Cluster Entropy Profile Tables (ACCEPT), we confirm that BCGs in low central entropy clusters are well aligned with the X-ray center. Additionally, the magnitude difference between BCG and the second brightest galaxy also correlates with the central entropy of the intracluster medium. From the red-sequence (RS) galaxies, we cannot find significant dependence of RS color scatter and stellar population on the central entropy of the intracluster medium of their host cluster. However, BCGs in low-entropy clusters are systematically less massive than those in high-entropy clusters, although this is dependent on the method used to derive the stellar mass of BCGs. In contrast, the stellar velocity dispersion of BCGs shows no dependence on BCG activity and cluster central entropy. This implies that the potential of the BCG is established earlier and the activity leading to optical emission lines is dictated by the properties of the intracluster medium in the cluster core.

  20. The Host Galaxies of Fast-Ejecta Core-Collapse Supernovae

    NASA Technical Reports Server (NTRS)

    Kelly, Patrick L.; Filippenko, Alexei V.; Modjaz, Maryam; Kocevski, Daniel

    2014-01-01

    Spectra of broad-lined Type Ic supernovae (SN Ic-BL), the only kind of SN observed at the locations of long-duration gamma-ray bursts (LGRBs), exhibit wide features indicative of high ejecta velocities ((is) approximately 0.1c). We study the host galaxies of a sample of 245 low-redshift (z (is) less than 0.2) core-collapse SN, including 17 SN Ic-BL, discovered by galaxy-untargeted searches, and 15 optically luminous and dust-obscured z (is) less than 1.2 LGRBs. We show that, in comparison with SDSS galaxies having similar stellar masses, the hosts of low-redshift SN Ic- BL and z (is) is less than 1.2 LGRBs have high stellar-mass and star-formation-rate densities. Core-collapse SN having typical ejecta velocities, in contrast, show no preference for such galaxies. Moreover, we find that the hosts of SN Ic-BL, unlike those of SN Ib/Ic and SN II, exhibit high gas velocity dispersions for their stellar masses. The patterns likely reflect variations among star-forming environments, and suggest that LGRBs can be used as probes of conditions in high-redshift galaxies. They may be caused by efficient formation of massive binary progenitors systems in densely star-forming regions, or, less probably, a higher fraction of stars created with the initial masses required for a SN Ic-BL or LGRB. Finally, we show that the preference of SN Ic-BL and LGRBs for galaxies with high stellar-mass and star-formation-rate densities cannot be attributed to a preference for low metal abundances but must reflect the influence of a separate environmental factor.

  1. The host galaxies of fast-ejecta core-collapse supernovae

    SciTech Connect

    Kelly, Patrick L.; Filippenko, Alexei V.; Modjaz, Maryam; Kocevski, Daniel

    2014-07-01

    Spectra of broad-lined Type Ic supernovae (SNe Ic-BL), the only kind of SN observed at the locations of long-duration gamma-ray bursts (LGRBs), exhibit wide features indicative of high ejecta velocities (∼0.1c). We study the host galaxies of a sample of 245 low-redshift (z < 0.2) core-collapse SNe, including 17 SNe Ic-BL, discovered by galaxy-untargeted searches, and 15 optically luminous and dust-obscured z < 1.2 LGRBs. We show that, in comparison with Sloan Digital Sky Survey galaxies having similar stellar masses, the hosts of low-redshift SNe Ic-BL and z < 1.2 LGRBs have high stellar mass and star formation rate densities. Core-collapse SNe having typical ejecta velocities, in contrast, show no preference for such galaxies. Moreover, we find that the hosts of SNe Ic-BL, unlike those of SNe Ib/Ic and SNe II, exhibit high gas velocity dispersions for their stellar masses. The patterns likely reflect variations among star-forming environments and suggest that LGRBs can be used as probes of conditions in high-redshift galaxies. They may be caused by efficient formation of massive binary progenitor systems in densely star-forming regions, or, less probably, a higher fraction of stars created with the initial masses required for an SN Ic-BL or LGRB. Finally, we show that the preference of SNe Ic-BL and LGRBs for galaxies with high stellar mass and star formation rate densities cannot be attributed to a preference for low metal abundances but must reflect the influence of a separate environmental factor.

  2. The host galaxies of active galactic nuclei with powerful relativistic jets

    NASA Astrophysics Data System (ADS)

    Olguín-Iglesias, A.; León-Tavares, J.; Kotilainen, J. K.; Chavushyan, V.; Tornikoski, M.; Valtaoja, E.; Añorve, C.; Valdés, J.; Carrasco, L.

    2016-08-01

    We present deep near-infrared (NIR) images of a sample of 19 intermediate-redshift (0.3 < z < 1.0) radio-loud active galactic nuclei (AGN) with powerful relativistic jets (L1.4 GHz > 1027 W Hz-1), previously classified as flat-spectrum radio quasars. We also compile host galaxy and nuclear magnitudes for blazars from literature. The combined sample (this work and compilation) contains 100 radio-loud AGN with host galaxy detections and a broad range of radio luminosities L1.4 GHz ˜ 1023.7-1028.3 W Hz-1, allowing us to divide our sample into high-luminosity blazars (HLBs) and low-luminosity blazars (LLBs). The host galaxies of our sample are bright and seem to follow the μe-Reff relation for ellipticals and bulges. The two populations of blazars show different behaviours in the MK,nuclear -MK,bulge plane, where a statistically significant correlation is observed for HLBs. Although it may be affected by selection effects, this correlation suggests a close coupling between the accretion mode of the central supermassive black hole and its host galaxy, which could be interpreted in terms of AGN feedback. Our findings are consistent with semi-analytical models where low-luminosity AGN emit the bulk of their energy in the form of radio jets, producing a strong feedback mechanism, and high-luminosity AGN are affected by galaxy mergers and interactions, which provide a common supply of cold gas to feed both nuclear activity and star formation episodes.

  3. The GRB 030329 host: a blue low metallicity subluminous galaxy with intense star formation

    NASA Astrophysics Data System (ADS)

    Gorosabel, J.; Pérez-Ramírez, D.; Sollerman, J.; de Ugarte Postigo, A.; Fynbo, J. P. U.; Castro-Tirado, A. J.; Jakobsson, P.; Christensen, L.; Hjorth, J.; Jóhannesson, G.; Guziy, S.; Castro Cerón, J. M.; Björnsson, G.; Sokolov, V. V.; Fatkhullin, T. A.; Nilsson, K.

    2005-12-01

    We present broad band photometry and spectroscopic observations of the host galaxy of GRB 030329. Analysis of the spectral emission lines shows that the host is likely a low metallicity galaxy (Z˜0.004). The spectral energy distribution (SED) constructed with the photometric points has been fitted using synthetic and observational templates. The best SED fit is obtained with a starburst template with an age of 150 Myr and an extinction Av ˜ 0.6. We find that the GRB 030329 host galaxy is a subluminous galaxy (L ˜ 0.016 Lstar) with a stellar mass of ≳ 108 M⊙. Three independent diagnostics, based on the restframe UV continuum, the [O II], and the Balmer emission lines, provide a consistent unextinguished star formation rate of ˜ 0.6 M⊙ yr-1, implying a high unextinguished specific star formation rate ( 34 M⊙ yr-1 (L/Lstar)-1). We estimate that the unextinguished specific star formation rate of the GRB 030329 host is higher than 93.5% of the galaxies at a similar redshift. Based on observations made with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway, and Sweden, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias. Based on data taken at the 2.2-m and 3.5-m telescopes of the Centro Astronómico Hispano Alemán de Calar Alto, operated by the Max Planck institute of Heidelberg and Centro Superior de Investigaciones Científicas. The spectral observations were obtained at the European Southern Observatory, Cerro Paranal (Chile), under the Director's Discretionary Time programme 271.D-5006(A).

  4. Supernova Candidate in MACSJ1149 Galaxy Cluster Field With No Detected Host Galaxy

    NASA Astrophysics Data System (ADS)

    Kelly, Patrick L.; Diego, Jose Maria; Nonino, Mario; Zitrin, Adi; Jauzac, Mathilde; Filippenko, Alexei V.

    2017-01-01

    We report discovery of a supernova (SN) candidate in the MACSJ1149 (z=0.54) galaxy-cluster field. In Hubble Space Telescope (HST) data taken on January 23, 2017 UT, we found a bright source (dubbed 'Amos') in WFC3 UVIS F606W ( 23.3 mag AB) and WFC3 IR F110W ( 23.7 mag) exposures.

  5. X-RAY SELECTED AGN HOST GALAXIES ARE SIMILAR TO INACTIVE GALAXIES OUT TO z = 3: RESULTS FROM CANDELS/CDF-S

    SciTech Connect

    Rosario, D. J.; Wuyts, S.; Nandra, K.; Mozena, M.; Faber, S. M.; Koo, D. C.; Koekemoer, A.; Ferguson, H.; Grogin, N.; McGrath, E.; Hathi, N. P.; Dekel, A.; Donley, J.; Dunlop, J. S.; Giavalisco, M.; Guo, Y.; Kocevski, D. D.; Laird, E.; Rangel, C.; Newman, J.; and others

    2013-01-20

    We use multi-band spatially resolved photometry from the Cosmic Assembly Near-IR Deep Legacy Survey in the 4 Ms Chandra Deep Field-South to explore the nuclear and extended colors, color gradients, and stellar populations of the host galaxies of X-ray selected active galactic nuclei (AGNs) out to z = 3. Based on a study of their central light, we develop X-ray based criteria to exclude objects with strong AGN contamination. We use stellar masses from the FIREWORKS database to understand and account for stellar mass selection effects and carefully study, for the first time, the resolved host galaxy properties of AGNs at z {approx} 2 in their rest-frame optical light without substantial nuclear contamination. AGN hosts span a sizable range of stellar masses, colors, and color gradients at these redshifts. Their colors, color gradients, and stellar population properties are very similar to inactive galaxies of the same stellar mass. At z {approx} 1, we find a slightly narrower range in host colors compared to inactive galaxies, as well as hints of more recent star formation. These differences are weaker or non-existent among AGN hosts at z {approx} 2. We discuss the importance of AGN-driven feedback in the quenching of galaxies at z {approx}> 1 and speculate on possible evolution in the relationship between black hole accretion and the host galaxy toward high redshifts.

  6. Supernovae and their host galaxies - III. The impact of bars and bulges on the radial distribution of supernovae in disc galaxies

    NASA Astrophysics Data System (ADS)

    Hakobyan, A. A.; Karapetyan, A. G.; Barkhudaryan, L. V.; Mamon, G. A.; Kunth, D.; Petrosian, A. R.; Adibekyan, V.; Aramyan, L. S.; Turatto, M.

    2016-03-01

    We present an analysis of the impact of bars and bulges on the radial distributions of the different types of supernovae (SNe) in the stellar discs of host galaxies with various morphologies. We use a well-defined sample of 500 nearby (≤100 Mpc) SNe and their low-inclined (i ≤ 60°) and morphologically non-disturbed S0-Sm host galaxies from the Sloan Digital Sky Survey. We find that in Sa-Sm galaxies, all core-collapse (CC) and vast majority of SNe Ia belong to the disc, rather than the bulge component. The radial distribution of SNe Ia in S0-S0/a galaxies is inconsistent with their distribution in Sa-Sm hosts, which is probably due to the contribution of the outer bulge SNe Ia in S0-S0/a galaxies. In Sa-Sbc galaxies, the radial distribution of CC SNe in barred hosts is inconsistent with that in unbarred ones, while the distributions of SNe Ia are not significantly different. At the same time, the radial distributions of both types of SNe in Sc-Sm galaxies are not affected by bars. We propose that the additional mechanism shaping the distributions of Type Ia and CC SNe can be explained within the framework of substantial suppression of massive star formation in the radial range swept by strong bars, particularly in early-type spirals. The radial distribution of CC SNe in unbarred Sa-Sbc galaxies is more centrally peaked and inconsistent with that in unbarred Sc-Sm hosts, while the distribution of SNe Ia in unbarred galaxies is not affected by host morphology. These results can be explained by the distinct distributions of massive stars in the discs of early- and late-type spirals.

  7. 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.

  8. LONG GRBs ARE METALLICITY-BIASED TRACERS OF STAR FORMATION: EVIDENCE FROM HOST GALAXIES AND REDSHIFT DISTRIBUTION

    SciTech Connect

    Wang, F. Y.; Dai, Z. G. E-mail: dzg@nju.edu.cn

    2014-07-01

    We investigate the mass distribution of long gamma-ray burst (GRB) host galaxies and the redshift distribution of long GRBs by considering that long GRBs occur in low-metallicity environments. We calculate the upper limit on the stellar mass of a galaxy which can produce long GRBs by utilizing the mass-metallicity (M-Z) relation of galaxies. After comparing with the observed GRB host galaxies masses, we find that the observed GRB host galaxy masses can fit the predicted masses well if GRBs occur in low-metallicity 12 + log (O/H){sub KK04} < 8.7. GRB host galaxies have low metallicity, low mass, and high star formation rate compared with galaxies of seventh data release of the Sloan Digital Sky Survey. We also study the cumulative redshift distribution of the latest Swift long GRBs by adding dark GRBs and 10 new GRBs redshifts from the TOUGH survey. The observed discrepancy between the GRB rate and the star formation history can be reconciled by considering that GRBs tend to occur in low-metallicity galaxies with 12 + log (O/H){sub KK04} < 8.7. We conclude that the metallicity cutoff that can produce long GRBs is about 12 + log (O/H){sub KK04} < 8.7 from the host mass distribution and redshift distribution.

  9. HST WFC3/IR OBSERVATIONS OF ACTIVE GALACTIC NUCLEUS HOST GALAXIES AT z {approx} 2: SUPERMASSIVE BLACK HOLES GROW IN DISK GALAXIES

    SciTech Connect

    Schawinski, Kevin; Urry, C. Megan; Treister, Ezequiel; Cardamone, Carolin N.; Simmons, Brooke; Yi, Sukyoung K.

    2011-02-01

    We present the rest-frame optical morphologies of active galactic nucleus (AGN) host galaxies at 1.5 < z < 3, using near-infrared imaging from the Hubble Space Telescope Wide Field Camera 3, the first such study of AGN host galaxies at these redshifts. The AGNs are X-ray-selected from the Chandra Deep Field South and have typical luminosities of 10{sup 42} erg s{sup -1}host galaxies of these AGNs have low Sersic indices indicative of disk-dominated light profiles, suggesting that secular processes govern a significant fraction of the cosmic growth of black holes. That is, many black holes in the present-day universe grew much of their mass in disk-dominated galaxies and not in early-type galaxies or major mergers. The properties of the AGN host galaxies are furthermore indistinguishable from their parent galaxy population and we find no strong evolution in either effective radii or morphological mix between z {approx} 2 and z {approx} 0.05.

  10. Supermassive black holes and their host galaxies. II. The correlation with near-infrared luminosity revisited

    SciTech Connect

    Läsker, Ronald; Van de Ven, Glenn; Ferrarese, Laura; Shankar, Francesco

    2014-01-01

    We present an investigation of the scaling relations between supermassive black hole (SMBH) masses, M {sub •}, and their host galaxies' K-band bulge (L {sub bul}) and total (L {sub tot}) luminosities. The wide-field WIRCam imager at the Canada-France-Hawaii-Telescope was used to obtain the deepest and highest resolution near-infrared images available for a sample of 35 galaxies with securely measured M {sub •}, selected irrespective of Hubble type. For each galaxy, we derive bulge and total magnitudes using a two-dimensional image decomposition code that allows us to account, if necessary, for large- and small-scale disks, cores, bars, nuclei, rings, envelopes, and spiral arms. We find that the present-day M {sub •}-L {sub bul} and M {sub •}-L {sub tot} relations have consistent intrinsic scatter, suggesting that M {sub •} correlates equally well with bulge and total luminosity of the host. Our analysis provides only mild evidence of a decreased scatter if the fit is restricted to elliptical galaxies. The log-slopes of the M {sub •}-L {sub bul} and M {sub •}-L {sub tot} relations are 0.75 ± 0.10 and 0.92 ± 0.14, respectively. However, while the slope of the M {sub •}-L {sub bul} relation depends on the detail of the image decomposition, the characterization of M {sub •}-L {sub tot} does not. Given the difficulties and ambiguities of decomposing galaxy images into separate components, our results indicate that L {sub tot} is more suitable as a tracer of SMBH mass than L {sub bul}, and that the M {sub •}-L {sub tot} relation should be used when studying the co-evolution of SMBHs and galaxies.

  11. A Herschel Study of 24 μμm-Selected AGNs and Their Host Galaxies

    NASA Astrophysics Data System (ADS)

    Xu, Lei; Rieke, G. H.; Egami, E.; Pereira, M. J.; Haines, C. P.; Smith, G. P.

    2015-08-01

    We present a sample of 290 24 μm-selected active galactic nuclei (AGNs) mostly at z ˜ 0.3-2.5, within 5.2 {{deg}}2 distributed as 25\\prime × 25\\prime fields around each of 30 galaxy clusters in the Local Cluster Substructure Survey. The sample is nearly complete to 1 mJy at 24 μm, and has a rich multiwavelength set of ancillary data; 162 are detected by Herschel. We use spectral templates for AGNs, stellar populations, and infrared (IR) emission by star-forming galaxies to decompose the spectral energy distributions (SEDs) of these AGNs and their host galaxies, and estimate their star formation rates, AGN luminosities, and host galaxy stellar masses. The set of templates is relatively simple: a standard Type-1 quasar template; another for the photospheric output of the stellar population; and a far-infrared star-forming template. For the Type-2 AGN SEDs, we substitute templates including internal obscuration, and some Type-1 objects require a warm component (T≳ 50 K). The individually Herschel-detected Type-1 AGNs and a subset of 17 Type-2 AGNs typically have luminosities \\gt {10}45 {ergs} {{{s}}}-1, and supermassive black holes of ˜ 3× {10}8 {M}⊙ emitting at ˜10% of the Eddington rate. We find them in about twice the numbers of AGNs identified in SDSS data in the same fields, i.e., they represent typical high-luminosity AGNs, not an IR-selected minority. These AGNs and their host galaxies are studied further in an accompanying paper.

  12. The impact of compact radio sources on their host galaxies: observations

    NASA Astrophysics Data System (ADS)

    Tadhunter, C.

    2016-02-01

    I review the observational evidence that CSS/GPS radio sources have a significant impact on the evolution of their host galaxies, particularly on the kpc-scales of the galaxy bulges. Starting with an overview of the observational evidence for jet-cloud interactions and warm ionised outflows in CSS/GPS sources, I then consider the challenges involved in quantifying the feedback effect of the warm outflows in terms of their mass outflow rates and kinetic powers. For the best-observed cases it is shown that the warm outflows may have a major negative feedback effect in the very central regions, but probably lack the power to heat and eject the full cool ISM contents of the host galaxies. In contrast, the recently-discovered neutral and molecular outflows are more massive and powerful and therefore carry more destructive potential. However, the feedback effect of such outflows is not necessarily negative: there is now clear observational evidence that the molecular outflows are formed as the hot, compressed gas cools behind fast shocks driven into the ISM by the relativistic jets. The natural endpoint of this process is the formation of stars. Therefore, jet-induced star formation may be a significant process in CSS/GPS radio galaxies. Finally, I discuss whether CSS/GPS sources are ``imposters'' in flux-limited radio samples, due the flux boosting of the radio sources by strong jet-cloud interactions in the early stages of radio source evolution.

  13. Systematic Effects in Type-1a Supernovae Surveys from Host Galaxy Spectra

    SciTech Connect

    Strauss, Michael A.

    2013-08-23

    The physical relation between the properties of Type Ia supernovae and their host galaxies is investigated. Such supernovae are used to constrain the properties of dark energy, making it crucial to understand their physical properties and to check for systematic effects relating to the stellar populations of the progenitor stars from which these supernovae arose. This grant found strong evidence for two distinct populations of supernovae, and correlations between the progenitor stellar populations and the nature of the supernova light curves.

  14. DISSECTING THE QUASAR MAIN SEQUENCE: INSIGHT FROM HOST GALAXY PROPERTIES

    SciTech Connect

    Sun, Jiayi; Shen, Yue

    2015-05-01

    The diverse properties of broad-line quasars appear to follow a well-defined main sequence along which the optical Fe ii strength increases. It has been suggested that this sequence is mainly driven by the Eddington ratio (L/L{sub Edd}) of the black hole (BH) accretion. Shen and Ho demonstrated with quasar clustering analysis that the average BH mass decreases with increasing Fe ii strength when quasar luminosity is fixed, consistent with this suggestion. Here we perform an independent test by measuring the stellar velocity dispersion σ{sub *} (hence, the BH mass via the M–σ{sub *} relation) from decomposed host spectra in low-redshift Sloan Digital Sky Survey quasars. We found that at fixed quasar luminosity, σ{sub *} systematically decreases with increasing Fe ii strength, confirming that the Eddington ratio increases with Fe ii strength. We also found that at fixed luminosity and Fe ii strength, there is little dependence of σ{sub *} on the broad Hβ FWHM. These new results reinforce the framework that the Eddington ratio and orientation govern most of the diversity seen in broad-line quasar properties.

  15. Origin of the Correlations Between Supermassive Black Holes and Their Host Galaxies

    NASA Astrophysics Data System (ADS)

    Sherman, Sydney; Li, Y.; Zhu, Q.

    2013-01-01

    It has been well established from observations that suppermassive black holes in nearby elliptical galaxies correlate tightly with the stellar velocity dispersion (the M - σ relation) and mass (the MBH - Mhost relation) of their host spheroids. However, the origin of these correlations remains ambiguous. Here, we compile a sample of observed galaxies with different properties (e.g., mass, type, kinematics, growth history, etc.) and examine the dependence of the above correlations on these parameters. We find that galaxies that satisfy the M - σ correlation appear to have reached virial equilibrium, as indicated by the ratio between kinetic energy and gravitational potential, 2K/U ~ 1. Furthermore, the ratio of black hole accretion rate to star formation rate remains nearly constant, AR /SFR ~ 10-3, over a wide range of galaxy mass from redshift z=0 - 2. These results confirm our previous theoretical model that the observed correlations have different origins: the M - σ relation may be the result of virial equilibrium, while MBH - Mhost relation may be the result of self-regulated star formation and black hole growth in galaxies.

  16. The Sloan Digital Sky Survey Reverberation Mapping Project: Post-Starburst Signatures in Quasar Host Galaxies at z > 1

    NASA Astrophysics Data System (ADS)

    Matsuoka, Yoshiki; Strauss, Michael A.; Shen, Yue; Brandt, William N.; Greene, Jenny E.; Ho, Luis C.; Schneider, Donald P.; Sun, Mouyuan; Trump, Jonathan R.

    2015-10-01

    Quasar host galaxies are key for understanding the relation between galaxies and the supermassive black holes (SMBHs) at their centers. We present a study of 191 broad-line quasars and their host galaxies at z\\lt 1, using high signal-to-noise ratio (S/N) spectra produced by the Sloan Digital Sky Survey Reverberation Mapping project. Clear detection of stellar absorption lines allows a reliable decomposition of the observed spectra into nuclear and host components, using spectral models of quasar and stellar radiations as well as emission lines from the interstellar medium. We estimate age, mass {M}*, and velocity dispersion {σ }* of the host stars, the star formation rate (SFR), quasar luminosity, and SMBH mass {M}\\bullet , for each object. The quasars are preferentially hosted by massive galaxies with {M}*˜ {10}11 {M}⊙ characterized by stellar ages around 1 billion yr, which coincides with the transition phase of normal galaxies from the blue cloud to the red sequence. The host galaxies have relatively low SFRs and fall below the main sequence of star-forming galaxies at similar redshifts. These facts suggest that the hosts have experienced an episode of major star formation sometime in the past 1 billion yr, which was subsequently quenched or suppressed. The derived {M}\\bullet -{σ }* and {M}\\bullet -{M}* relations agree with our past measurements and are consistent with no evolution from the local universe. The present analysis demonstrates that reliable measurements of stellar properties of quasar host galaxies are possible with high-S/N fiber spectra, which will be acquired in large numbers with future powerful instruments such as the Subaru Prime Focus Spectrograph.

  17. GRB host galaxies with VLT/X-Shooter: properties at 0.8 < z < 1.3

    NASA Astrophysics Data System (ADS)

    Piranomonte, S.; Japelj, J.; Vergani, S. D.; Savaglio, S.; Palazzi, E.; Covino, S.; Flores, H.; Goldoni, P.; Cupani, G.; Krühler, T.; Mannucci, F.; Onori, F.; Rossi, A.; D'Elia, V.; Pian, E.; D'Avanzo, P.; Gomboc, A.; Hammer, F.; Randich, S.; Fiore, F.; Stella, L.; Tagliaferri, G.

    2015-10-01

    Long gamma-ray bursts (LGRBs) are associated with the death of massive stars. Their host galaxies therefore represent a unique class of objects tracing star formation across the observable Universe. Indeed, recently accumulated evidence shows that GRB hosts do not differ substantially from general population of galaxies at high (z > 2) redshifts. However, it has been long recognized that the properties of z < 1.5 hosts, compared to general star-forming population, are unusual. To better understand the reasons for the supposed difference in LGRB hosts properties at z < 1.5, we obtained Very Large Telescope (VLT)/X-Shooter spectra of six hosts lying in the redshift range of 0.8 < z < 1.3. Some of these hosts have been observed before, yet we still lack well-constrained information on their characteristics such as metallicity, dust extinction and star formation rate (SFR). We search for emission lines in the VLT/X-Shooter spectra of the hosts and measure their fluxes. We perform a detailed analysis, estimating host average extinction, SFRs, metallicities and electron densities where possible. Measured quantities of our hosts are compared to a larger sample of previously observed GRB hosts at z < 2. SFRs and metallicities are measured for all the hosts analysed in this paper and metallicities are well determined for four hosts. The mass-metallicity relation, the fundamental metallicity relation and SFRs derived from our hosts occupy similar parameter space as other host galaxies investigated so far at the same redshift. We therefore conclude that GRB hosts in our sample support the found discrepancy between the properties of low-redshift GRB hosts and the general population of star-forming galaxies.

  18. The Post-starburst Evolution of Tidal Disruption Event Host Galaxies

    NASA Astrophysics Data System (ADS)

    French, K. Decker; Arcavi, Iair; Zabludoff, Ann

    2017-02-01

    We constrain the recent star formation histories of the host galaxies of eight optical/UV-detected tidal disruption events (TDEs). Six hosts had quick starbursts of <200 Myr duration that ended 10–1000 Myr ago, indicating that TDEs arise at different times in their hosts’ post-starburst evolution. If the disrupted star formed in the burst or before, the post-burst age constrains its mass, generally excluding O, most B, and highly massive A stars. If the starburst arose from a galaxy merger, the time since the starburst began limits the coalescence timescale and thus the merger mass ratio to more equal than 12:1 in most hosts. This uncommon ratio, if also that of the central supermassive black hole (SMBH) binary, disfavors the scenario in which the TDE rate is boosted by the binary but is insensitive to its mass ratio. The stellar mass fraction created in the burst is 0.5%–10% for most hosts, not enough to explain the observed 30–200× boost in TDE rates, suggesting that the host’s core stellar concentration is more important. TDE hosts have stellar masses 109.4–1010.3 M⊙, consistent with the Sloan Digital Sky Survey volume-corrected, quiescent Balmer-strong comparison sample and implying SMBH masses of 105.5–107.5 M⊙. Subtracting the host absorption line spectrum, we uncover emission lines; at least five hosts have ionization sources inconsistent with star formation that instead may be related to circumnuclear gas, merger shocks, or post-AGB stars.

  19. An evolutionary missing link? A modest-mass early-type galaxy hosting an oversized nuclear black hole

    NASA Astrophysics Data System (ADS)

    van Loon, Jacco Th.; Sansom, Anne E.

    2015-11-01

    SAGE1C J053634.78-722658.5 is a galaxy at redshift z = 0.14, discovered behind the Large Magellanic Cloud in the Spitzer Space Telescope`Surveying the Agents of Galaxy Evolution' Spectroscopy survey. It has very strong silicate emission at 10 μm but negligible far-IR and UV emission. This makes it a candidate for a bare active galactic nuclei (AGN) source in the IR, perhaps seen pole-on, without significant IR emission from the host galaxy. In this paper we present optical spectra taken with the Southern African Large Telescope to investigate the nature of the underlying host galaxy and its AGN. We find broad H α emission characteristic of an AGN, plus absorption lines associated with a mature stellar population (>9 Gyr), and refine its redshift determination to z = 0.1428 ± 0.0001. There is no evidence for any emission lines associated with star formation. This remarkable object exemplifies the need for separating the emission from any AGN from that of the host galaxy when employing IR diagnostic diagrams. We estimate the black hole mass, MBH = 3.5 ± 0.8 × 108 M⊙, host galaxy mass, M_stars=2.5^{2.5}_{1.2}× 10^{10} M⊙, and accretion luminosity, Lbol(AGN) = 5.3 ± 0.4 × 1045 erg s-1 (≈12 per cent of the Eddington luminosity), and find the AGN to be more prominent than expected for a host galaxy of this modest size. The old age is in tension with the downsizing paradigm in which this galaxy would recently have transformed from a star-forming disc galaxy into an early-type, passively evolving galaxy.

  20. The Connection between the Host Halo and the Satellite Galaxies of the Milky Way

    NASA Astrophysics Data System (ADS)

    Lu, Yu; Benson, Andrew; Mao, Yao-Yuan; Tonnesen, Stephanie; Peter, Annika H. G.; Wetzel, Andrew R.; Boylan-Kolchin, Michael; Wechsler, Risa H.

    2016-10-01

    Many properties of the Milky Way’s (MW) dark matter halo, including its mass-assembly history, concentration, and subhalo population, remain poorly constrained. We explore the connection between these properties of the MW and its satellite galaxy population, especially the implication of the presence of the Magellanic Clouds for the properties of the MW halo. Using a suite of high-resolution N-body simulations of MW-mass halos with a fixed final {M}{vir}˜ {10}12.1 {M}⊙ , we find that the presence of Magellanic Cloud-like satellites strongly correlates with the assembly history, concentration, and subhalo population of the host halo, such that MW-mass systems with Magellanic Clouds have lower concentration, more rapid recent accretion, and more massive subhalos than typical halos of the same mass. Using a flexible semi-analytic galaxy formation model that is tuned to reproduce the stellar mass function of the classical dwarf galaxies of the MW with Markov-Chain Monte-Carlo, we show that adopting host halos with different mass-assembly histories and concentrations can lead to different best-fit models for galaxy-formation physics, especially for the strength of feedback. These biases arise because the presence of the Magellanic Clouds boosts the overall population of high-mass subhalos, thus requiring a different stellar-mass-to-halo-mass ratio to match the data. These biases also lead to significant differences in the mass-metallicity relation, the kinematics of low-mass satellites, the number counts of small satellites associated with the Magellanic Clouds, and the stellar mass of MW itself. Observations of these galaxy properties can thus provide useful constraints on the properties of the MW halo.

  1. The connection between the host halo and the satellite galaxies of the Milky Way

    SciTech Connect

    Lu, Yu; Benson, Andrew; Mao, Yao -Yuan; Tonnesen, Stephanie; Peter, Annika H. G.; Wetzel, Andrew R.; Boylan-Kolchin, Michael; Wechsler, Risa H.

    2016-10-11

    Many properties of the Milky Way's (MW) dark matter halo, including its mass-assembly history, concentration, and subhalo population, remain poorly constrained. We explore the connection between these properties of the MW and its satellite galaxy population, especially the implication of the presence of the Magellanic Clouds for the properties of the MW halo. Using a suite of high-resolution N-body simulations of MW-mass halos with a fixed final ${M}_{\\mathrm{vir}}\\sim {10}^{12.1}\\,{M}_{\\odot }$, we find that the presence of Magellanic Cloud-like satellites strongly correlates with the assembly history, concentration, and subhalo population of the host halo, such that MW-mass systems with Magellanic Clouds have lower concentration, more rapid recent accretion, and more massive subhalos than typical halos of the same mass. Using a flexible semi-analytic galaxy formation model that is tuned to reproduce the stellar mass function of the classical dwarf galaxies of the MW with Markov-Chain Monte-Carlo, we show that adopting host halos with different mass-assembly histories and concentrations can lead to different best-fit models for galaxy-formation physics, especially for the strength of feedback. These biases arise because the presence of the Magellanic Clouds boosts the overall population of high-mass subhalos, thus requiring a different stellar-mass-to-halo-mass ratio to match the data. These biases also lead to significant differences in the mass–metallicity relation, the kinematics of low-mass satellites, the number counts of small satellites associated with the Magellanic Clouds, and the stellar mass of MW itself. Finally, observations of these galaxy properties can thus provide useful constraints on the properties of the MW halo.

  2. The connection between the host halo and the satellite galaxies of the Milky Way

    DOE PAGES

    Lu, Yu; Benson, Andrew; Mao, Yao -Yuan; ...

    2016-10-11

    Many properties of the Milky Way's (MW) dark matter halo, including its mass-assembly history, concentration, and subhalo population, remain poorly constrained. We explore the connection between these properties of the MW and its satellite galaxy population, especially the implication of the presence of the Magellanic Clouds for the properties of the MW halo. Using a suite of high-resolution N-body simulations of MW-mass halos with a fixed finalmore » $${M}_{\\mathrm{vir}}\\sim {10}^{12.1}\\,{M}_{\\odot }$$, we find that the presence of Magellanic Cloud-like satellites strongly correlates with the assembly history, concentration, and subhalo population of the host halo, such that MW-mass systems with Magellanic Clouds have lower concentration, more rapid recent accretion, and more massive subhalos than typical halos of the same mass. Using a flexible semi-analytic galaxy formation model that is tuned to reproduce the stellar mass function of the classical dwarf galaxies of the MW with Markov-Chain Monte-Carlo, we show that adopting host halos with different mass-assembly histories and concentrations can lead to different best-fit models for galaxy-formation physics, especially for the strength of feedback. These biases arise because the presence of the Magellanic Clouds boosts the overall population of high-mass subhalos, thus requiring a different stellar-mass-to-halo-mass ratio to match the data. These biases also lead to significant differences in the mass–metallicity relation, the kinematics of low-mass satellites, the number counts of small satellites associated with the Magellanic Clouds, and the stellar mass of MW itself. Finally, observations of these galaxy properties can thus provide useful constraints on the properties of the MW halo.« less

  3. Using diffusion k-means for simple stellar population modeling of low S/N quasar host galaxy spectra

    NASA Astrophysics Data System (ADS)

    Mosby, Gregory; Tremonti, Christina A.; Hooper, Eric; Wolf, Marsha J.; Sheinis, Andrew; Richards, Joseph

    2016-01-01

    Quasar host galaxies (QHGs) represent a unique stage in galaxy evolution that can provide a glimpse into the relationship between an active supermassive black hole (SMBH) and its host galaxy. However, observing the hosts of high luminosity, unobscured quasars in the optical is complicated by the large ratio of quasar to host galaxy light. One strategy in optical spectroscopy is to use offset longslit observations of the host galaxy. This method allows the centers of QHGs to be analyzed apart from other regions of their host galaxies. But light from the accreting black hole's point spread function still enters the host galaxy observations, and where the contrast between the host and intervening quasar light is favorable, the host galaxy is faint, producing low signal-to-noise (S/N) data. This stymies traditional stellar population methods that might rely on high S/N features in galaxy spectra to recover key galaxy properties like its star formation history (SFH). In response to this challenge, we have developed a method of stellar population modeling using diffusion k-means (DFK) that can recover SFHs from rest frame optical data with S/N ~ 5 Å^-1. Specifically, we use DFK to cultivate a reduced stellar population basis set. This DFK basis set of four broad age bins is able to recover a range of SFHs. With an analytic description of the seeing, we can use this DFK basis set to simultaneously model the SFHs and the intervening quasar light of QHGs as well. We compare the results of this method with previous techniques using synthetic data and find that our new method has a clear advantage in recovering SFHs from QHGs. On average, the DFK basis set is just as accurate and decisively more precise. This new technique could be used to analyze other low S/N galaxy spectra like those from higher redshift or integral field spectroscopy surveys.This material is based upon work supported by the National Science Foundation under grant no. DGE -0718123 and the Advanced

  4. A Refined QSO Selection Method Using Diagnostics

    NASA Astrophysics Data System (ADS)

    Kim, Dae-Won; Protopapas, Pavlos; Trichas, Markos; Rowan-Robinson, Michael; Khardon, Roni; Alcock, Charles; Byun, Yong-Ik

    2012-04-01

    We present 663 QSO candidates in the Large Magellanic Cloud (LMC) that were selected using multiple diagnostics. We started with a set of 2,566 QSO candidates selected using the methodology presented in our previous work based on time variability of the MACHO LMC light curves. We then obtained additional information for the candidates by cross-matching them with the Spitzer SAGE, the 2MASS, the Chandra, the XMM, and an LMC UBVI catalogues. Using that information, we specified diagnostic features based on mid-IR colours, photometric redshifts using SED template fitting, and X-ray luminosities, in order to discriminate more high-confidence QSO candidates in the absence of spectral information. We then trained a one-class Support Vector Machine model using those diagnostics features. We applied the trained model to the original candidates, and finally selected 663 high-confidence QSO candidates. We cross-matched those 663 QSO candidates with 152 newly-confirmed QSOs and 275 non-QSOs in the LMC fields, and found that the false positive rate was less than 1%.

  5. ON THE DEPENDENCE OF TYPE Ia SNe LUMINOSITIES ON THE METALLICITY OF THEIR HOST GALAXIES

    SciTech Connect

    Moreno-Raya, Manuel E.; Mollá, Mercedes; López-Sánchez, Ángel R.; Galbany, Lluís; Vílchez, José Manuel; Rosell, Aurelio Carnero; Domínguez, Inmaculada

    2016-02-10

    The metallicity of the progenitor system producing a type Ia supernova (SN Ia) could play a role in its maximum luminosity, as suggested by theoretical predictions. We present an observational study to investigate if such a relationship exists. Using the 4.2 m William Herschel Telescope (WHT) we have obtained intermediate-resolution spectroscopy data of a sample of 28 local galaxies hosting SNe Ia, for which distances have been derived using methods independent of those based on SN Ia parameters. From the emission lines observed in their optical spectra, we derived the gas-phase oxygen abundance in the region where each SN Ia exploded. Our data show a trend, with an 80% of chance not being due to random fluctuation, between SNe Ia absolute magnitudes and the oxygen abundances of the host galaxies, in the sense that luminosities tend to be higher for galaxies with lower metallicities. This result seems likely to be in agreement with both the theoretically expected behavior and with other observational results. This dependence M{sub B}–Z might induce systematic errors when it is not considered when deriving SNe Ia luminosities and then using them to derive cosmological distances.

  6. On the Dependence of Type Ia SNe Luminosities on the Metallicity of Their Host Galaxies

    NASA Astrophysics Data System (ADS)

    Moreno-Raya, Manuel E.; Mollá, Mercedes; López-Sánchez, Ángel R.; Galbany, Lluís; Vílchez, José Manuel; Carnero Rosell, Aurelio; Domínguez, Inmaculada

    2016-02-01

    The metallicity of the progenitor system producing a type Ia supernova (SN Ia) could play a role in its maximum luminosity, as suggested by theoretical predictions. We present an observational study to investigate if such a relationship exists. Using the 4.2 m William Herschel Telescope (WHT) we have obtained intermediate-resolution spectroscopy data of a sample of 28 local galaxies hosting SNe Ia, for which distances have been derived using methods independent of those based on SN Ia parameters. From the emission lines observed in their optical spectra, we derived the gas-phase oxygen abundance in the region where each SN Ia exploded. Our data show a trend, with an 80% of chance not being due to random fluctuation, between SNe Ia absolute magnitudes and the oxygen abundances of the host galaxies, in the sense that luminosities tend to be higher for galaxies with lower metallicities. This result seems likely to be in agreement with both the theoretically expected behavior and with other observational results. This dependence MB-Z might induce systematic errors when it is not considered when deriving SNe Ia luminosities and then using them to derive cosmological distances.

  7. The Role of Radiation Pressure in the Narrow Line Regions of Seyfert Host Galaxies

    NASA Astrophysics Data System (ADS)

    Davies, Rebecca L.; Dopita, Michael A.; Kewley, Lisa; Groves, Brent; Sutherland, Ralph; Hampton, Elise J.; Shastri, Prajval; Kharb, Preeti; Bhatt, Harish; Scharwächter, Julia; Jin, Chichuan; Banfield, Julie; Zaw, Ingyin; James, Bethan; Juneau, Stéphanie; Srivastava, Shweta

    2016-06-01

    We investigate the relative significance of radiation pressure and gas pressure in the extended narrow line regions (ENLRs) of four Seyfert galaxies from the integral field Siding Spring Southern Seyfert Spectroscopic Snapshot Survey (S7). We demonstrate that there exist two distinct types of starburst-active galactic nucleus (AGN) mixing curves on standard emission line diagnostic diagrams, which reflect the balance between gas pressure and radiation pressure in the ENLR. In two of the galaxies the ENLR is radiation pressure dominated throughout and the ionization parameter remains constant (log U ˜ 0). In the other two galaxies radiation pressure is initially important, but gas pressure becomes dominant as the ionization parameter in the ENLR decreases from log U ˜ 0 to -3.2 ≲ log U ≲ -3.4. Where radiation pressure is dominant, the AGN regulates the density of the interstellar medium on kiloparsec scales and may therefore have a direct impact on star formation activity and/or the incidence of outflows in the host galaxy to scales far beyond the zone of influence of the black hole. We find that both radiation pressure dominated and gas pressure dominated ENLRs are dynamically active with evidence for outflows, indicating that radiation pressure may be an important source of AGN feedback even when it is not dominant over the entire ENLR.

  8. HUBBLE SPACE TELESCOPE Observations of the Host Galaxy of GRB 970508

    NASA Astrophysics Data System (ADS)

    Fruchter, A. S.; Pian, E.; Gibbons, R.; Thorsett, S. E.; Ferguson, H.; Petro, L.; Sahu, K. C.; Livio, M.; Caraveo, P.; Frontera, F.; Kouveliotou, C.; Macchetto, D.; Palazzi, E.; Pedersen, H.; Tavani, M.; van Paradijs, J.

    2000-12-01

    We report on observations of the field of GRB 970508 made in 1998 early August, 454 days after outburst, with the STIS CCD camera on board the Hubble Space Telescope (HST). The images, taken in open filter (50CCD) mode, clearly reveal the presence of a galaxy that was overwhelmed in earlier (1997 June) HST images by emission from the optical transient (OT). The galaxy is regular in shape: after correcting for the HST/STIS PSF, it is well fitted by an exponential disk with a scale length of 0.046"+/-0.006" and an ellipticity of 0.70+/-0.07. All observations are marginally consistent with a continuous decline in OT emission as t-1.3 beginning 2 days after outburst; however, we find no direct evidence in the late-time HST image for emission from the OT, and the surface brightness profile of the galaxy is most regular if we assume that the OT emission is negligible, suggesting that the OT may have faded more rapidly at late times than is predicted by the power-law decay. Due to the wide bandwidth of the STIS clear mode, the estimated magnitude of the galaxy is dependent on the galaxy spectrum that is assumed. Using colors obtained from late-time ground-based observations to constrain the spectrum, we find V=25.4+/-0.15, a few tenths of a magnitude brighter than earlier ground-based estimates that were obtained by observing the total light of the galaxy and the OT and then subtracting the estimated OT brightness, assuming that it fades as a single power law. This again suggests that the OT may have faded faster at late time than the power law predicts. The position of the OT agrees with that of the isophotal center of the galaxy to 0.01", which, at the galaxy redshift z=0.83, corresponds to an offset from the center of the host of <~70 pc. This remarkable agreement raises the possibility that the gamma-ray burst may have been associated with either an active galactic nucleus or a nuclear starburst.

  9. VizieR Online Data Catalog: BH masses & host galaxy dispersion vel. (van den Bosch, 2016)

    NASA Astrophysics Data System (ADS)

    van den Bosch, R. C. E.

    2017-02-01

    According to the virial theorem, all gravitational systems in equilibrium sit on a plane in the three-dimensional parameter space defined by their mass, size, and second moment of the velocity tensor. While these quantities cannot be directly observed, there are suitable proxies: the luminosity Lk, half-light radius Re, and dispersion σe. These proxies indeed lie on a very tight fundamental plane (FP). How do the black holes (BHs) in the centers of galaxies relate to the FP? Their masses are known to exhibit no strong correlation with total galaxy mass, but they do correlate weakly with bulge mass (when present), and extremely well with the velocity dispersion through the M{bullet}∝σe5.4 relation. These facts together imply that a tight plane must also exist defined by BH mass, total galaxy mass, and size. Here, I show that this is indeed the case using a heterogeneous set of 230 BHs. The sample includes BHs from zero to 10 billion solar masses and host galaxies ranging from low surface brightness dwarfs, through bulgeless disks, to brightest cluster galaxies. The resulting BH-size-luminosity relation M{bullet}∝(Lk/Re)3.8 has the same amount of scatter as the M*-σ relation and is aligned with the galaxy FP, such that it is just a reprojection of σe. The inferred BH-size-mass relation is M{bullet}∝(M*/Re)2.9. These relationships are universal and extend to galaxies without bulges. This implies that the BH is primarily correlated with its global velocity dispersion and not with the properties of the bulge. I show that the classical bulge-mass relation is a projection of the M*-σ relation. When the velocity dispersion cannot be measured (at high z or low dispersions), the BH-size-mass relation should be used as a proxy for BH mass in favor of just galaxy or bulge mass. (4 data files).

  10. [C II] 158-μm emission from the host galaxies of damped Lyman-alpha systems

    NASA Astrophysics Data System (ADS)

    Neeleman, Marcel; Kanekar, Nissim; Prochaska, J. Xavier; Rafelski, Marc; Carilli, Chris L.; Wolfe, Arthur M.

    2017-03-01

    Gas surrounding high-redshift galaxies has been studied through observations of absorption line systems toward background quasars for decades. However, it has proven difficult to identify and characterize the galaxies associated with these absorbers due to the intrinsic faintness of the galaxies compared with the quasars at optical wavelengths. Using the Atacama Large Millimeter/Submillimeter Array, we report on detections of [C II] 158-μm line and dust-continuum emission from two galaxies associated with two such absorbers at a redshift of z ~ 4. Our results indicate that the hosts of these high-metallicity absorbers have physical properties similar to massive star-forming galaxies and are embedded in enriched neutral hydrogen gas reservoirs that extend well beyond the star-forming interstellar medium of these galaxies.

  11. [C ii] 158-μm emission from the host galaxies of damped Lyman-alpha systems.

    PubMed

    Neeleman, Marcel; Kanekar, Nissim; Prochaska, J Xavier; Rafelski, Marc; Carilli, Chris L; Wolfe, Arthur M

    2017-03-24

    Gas surrounding high-redshift galaxies has been studied through observations of absorption line systems toward background quasars for decades. However, it has proven difficult to identify and characterize the galaxies associated with these absorbers due to the intrinsic faintness of the galaxies compared with the quasars at optical wavelengths. Using the Atacama Large Millimeter/Submillimeter Array, we report on detections of [C ii] 158-μm line and dust-continuum emission from two galaxies associated with two such absorbers at a redshift of z ~ 4. Our results indicate that the hosts of these high-metallicity absorbers have physical properties similar to massive star-forming galaxies and are embedded in enriched neutral hydrogen gas reservoirs that extend well beyond the star-forming interstellar medium of these galaxies.

  12. GALAXY ZOO: THE FUNDAMENTALLY DIFFERENT CO-EVOLUTION OF SUPERMASSIVE BLACK HOLES AND THEIR EARLY- AND LATE-TYPE HOST GALAXIES

    SciTech Connect

    Schawinski, Kevin; Urry, C. Megan; Virani, Shanil; Coppi, Paolo; Cardamone, Carolin N.; Bamford, Steven P.; Treister, Ezequiel; Lintott, Chris J.; Kaviraj, Sugata; Sarzi, Marc; Keel, William C.; Masters, Karen L.; Nichol, Robert C.; Thomas, Daniel; Ross, Nicholas P.; Andreescu, Dan; Murray, Phil; Raddick, M. Jordan; Szalay, Alex S.; Slosar, Anze

    2010-03-01

    We use data from the Sloan Digital Sky Survey and visual classifications of morphology from the Galaxy Zoo project to study black hole growth in the nearby universe (z < 0.05) and to break down the active galactic nucleus (AGN) host galaxy population by color, stellar mass, and morphology. We find that the black hole growth at luminosities L[O{sub III}]>10{sup 40} erg s{sup -1} in early- and late-type galaxies is fundamentally different. AGN host galaxies as a population have a broad range of stellar masses (10{sup 10}-10{sup 11} M{sub sun}), reside in the green valley of the color-mass diagram and their central black holes have median masses around 10{sup 6.5} M{sub sun}. However, by comparing early- and late-type AGN host galaxies to their non-active counterparts, we find several key differences: in early-type galaxies, it is preferentially the galaxies with the least massive black holes that are growing, while in late-type galaxies, it is preferentially the most massive black holes that are growing. The duty cycle of AGNs in early-type galaxies is strongly peaked in the green valley below the low-mass end (10{sup 10} M{sub sun}) of the red sequence at stellar masses where there is a steady supply of blue cloud progenitors. The duty cycle of AGNs in late-type galaxies on the other hand peaks in massive (10{sup 11} M{sub sun}) green and red late-types which generally do not have a corresponding blue cloud population of similar mass. At high-Eddington ratios (L/L{sub Edd}>0.1), the only population with a substantial fraction of AGNs are the low-mass green valley early-type galaxies. Finally, the Milky Way likely resides in the 'sweet spot' on the color-mass diagram where the AGN duty cycle of late-type galaxies is highest. We discuss the implications of these results for our understanding of the role of AGNs in the evolution of galaxies.

  13. A tale of two feedbacks: Star formation in the host galaxies of radio AGNs

    SciTech Connect

    Karouzos, Marios; Im, Myungshin; Jeon, Yiseul; Kim, Ji Hoon; Trichas, Markos; Goto, Tomo; Malkan, Matt; Ruiz, Angel; Lee, Hyung Mok; Kim, Seong Jin; Oi, Nagisa; Matsuhara, Hideo; Takagi, Toshinobu; Murata, K.; Wada, Takehiko; Wada, Kensuke; Shim, Hyunjin; Hanami, Hitoshi; Serjeant, Stephen; White, Glenn J.; and others

    2014-04-01

    Several lines of argument support the existence of a link between activity at the nuclei of galaxies, in the form of an accreting supermassive black hole, and star formation activity in these galaxies. Radio jets have long been argued to be an ideal mechanism that allows active galactic nuclei (AGNs) to interact with their host galaxies and affect star formation. We use a sample of radio sources in the North Ecliptic Pole (NEP) field to study the nature of this putative link, by means of spectral energy distribution (SED) fitting. We employ the excellent spectral coverage of the AKARI infrared space telescope and the rich ancillary data available in the NEP to build SEDs extending from UV to far-IR wavelengths. We find a significant AGN component in our sample of relatively faint radio sources (host galaxy, independent of the radio luminosity. In contrast, for narrow redshift and AGN luminosity ranges, we find that increasing radio luminosity leads to a decrease in the specific star formation rate. The most radio-loud AGNs are found to lie on the main sequence of star formation for their respective redshifts. For the first time, we potentially see such a two-sided feedback process in the same sample. We discuss the possible suppression of star formation, but not total quenching, in systems with strong radio jets, that supports the maintenance nature of feedback from radio AGN jets.

  14. LATE-TIME OBSERVATIONS OF GRB 080319B: JET BREAK, HOST GALAXY, AND ACCOMPANYING SUPERNOVA

    SciTech Connect

    Tanvir, N. R.; O'Brien, P. T.; Wiersema, K.; Starling, R. L. C.; Rol, E.; Levan, A. J.; Svensson, K.; Fruchter, A. S.; Granot, J.; Jakobsson, P.; Fynbo, J.; Hjorth, J.; Curran, P. A.; Burrows, D. N.; Genet, F.

    2010-12-10

    The Swift-discovered GRB 080319B was by far the most distant source ever observed at naked-eye brightness, reaching a peak apparent magnitude of 5.3 at a redshift of z = 0.937. We present our late-time optical (Hubble Space Telescope, Gemini, and Very Large Telescope) and X-ray (Chandra) observations, which confirm that an achromatic break occurred in the power-law afterglow light curve at {approx}11 days post-burst. This most likely indicates that the gamma-ray burst (GRB) outflow was collimated, which for a uniform jet would imply a total energy in the jet E{sub jet} {approx}> 10{sup 52} erg. Our observations also show a late-time excess of red light, which is well explained if the GRB was accompanied by a supernova (SN), similar to those seen in some other long-duration GRBs. The latest observations are dominated by light from the host and show that the GRB took place in a faint dwarf galaxy (r(AB) {approx} 27.0, rest frame M{sub B} {approx} -17.2). This galaxy is small even by the standards of other GRB hosts, which is suggestive of a low-metallicity environment. Intriguingly, the properties of this extreme event-a small host and bright SN-are entirely typical of the very low luminosity bursts such as GRB 980425 and GRB 060218.

  15. THE AFTERGLOW AND ULIRG HOST GALAXY OF THE DARK SHORT GRB 120804A

    SciTech Connect

    Berger, E.; Zauderer, B. A.; Margutti, R.; Laskar, T.; Fong, W.; Chornock, R.; Dupuy, T. J.; Levan, A.; Tunnicliffe, R. L.; Mangano, V.; Fox, D. B.; Tanvir, N. R.; Menten, K. M.; Hjorth, J.; Roth, K.

    2013-03-10

    We present the optical discovery and subarcsecond optical and X-ray localization of the afterglow of the short GRB 120804A, as well as optical, near-IR, and radio detections of its host galaxy. X-ray observations with Swift/XRT, Chandra, and XMM-Newton extending to {delta}t Almost-Equal-To 19 days reveal a single power-law decline. The optical afterglow is faint, and comparison to the X-ray flux indicates that GRB 120804A is ''dark'', with a rest-frame extinction of A {sup host}{sub V} Almost-Equal-To 2.5 mag (at z = 1.3). The intrinsic neutral hydrogen column density inferred from the X-ray spectrum, N{sub H,{sub int}}(z = 1.3) Almost-Equal-To 2 Multiplication-Sign 10{sup 22} cm{sup -2}, is commensurate with the large extinction. The host galaxy exhibits red optical/near-IR colors. Equally important, JVLA observations at Almost-Equal-To 0.9-11 days reveal a constant flux density of F{sub {nu}}(5.8 GHz) = 35 {+-} 4 {mu}Jy and an optically thin spectrum, unprecedented for GRB afterglows, but suggestive instead of emission from the host galaxy. The optical/near-IR and radio fluxes are well fit with the scaled spectral energy distribution of the local ultraluminous infrared galaxy (ULIRG) Arp 220 at z Almost-Equal-To 1.3, with a resulting star formation rate of x Almost-Equal-To 300 M{sub Sun} yr{sup -1}. The inferred extinction and small projected offset (2.2 {+-} 1.2 kpc) are also consistent with the ULIRG scenario, as is the presence of a companion galaxy at the same redshift and with a separation of about 11 kpc. The limits on radio afterglow emission, in conjunction with the observed X-ray and optical emission, require a circumburst density of n {approx} 10{sup -3} cm{sup -3}, an isotropic-equivalent energy scale of E{sub {gamma},{sub iso}} Almost-Equal-To E{sub K,{sub iso}} Almost-Equal-To 7 Multiplication-Sign 10{sup 51} erg, and a jet opening angle of {theta}{sub j} {approx}> 11 Degree-Sign . The expected fraction of luminous infrared galaxies in the short GRB

  16. Towards a comprehensive picture of powerful quasars, their host galaxies and quasar winds at z ˜ 0.5

    NASA Astrophysics Data System (ADS)

    Wylezalek, Dominika; Zakamska, Nadia L.; Liu, Guilin; Obied, Georges

    2016-03-01

    Luminous type-2 quasars in which the glow from the central black hole is obscured by dust are ideal targets for studying their host galaxies and the quasars' effect on galaxy evolution. Such feedback appears ubiquitous in luminous obscured quasars where high-velocity-ionized nebulae have been found. We present rest-frame yellow-band (˜5000 Å) observations using the Hubble Space Telescope (HST) for a sample of 20 luminous quasar host galaxies at 0.2 < z < 0.6 selected from the Sloan Digital Sky Survey. For the first time, we combine host galaxy observations with geometric measurements of quasar illumination using blue-band HST observations and [O III] integral field unit observations probing the quasar winds. The HST images reveal bright merger signatures in about half the galaxies; a significantly higher fraction than in comparison inactive ellipticals. We show that the host galaxies are primarily bulge-dominated, with masses close to M*, but belong to <30 per cent of elliptical galaxies that are highly star forming at z ˜ 0.5. Ionized gas signatures are uncorrelated with faint stellar discs (if present), confirming that the ionized gas is not concentrated in a disc. Scattering cones and [O III] ionized gas velocity field are aligned with the forward scattering cones being co-spatial with the blue-shifted side of the velocity field, suggesting the high-velocity gas is indeed photo-ionized by the quasar. Based on the host galaxies' high star formation rates and bright merger signatures, we suggest that this low-redshift outbreak of luminous quasar activity is triggered by recent minor mergers. Combining these novel observations, we present new quasar unification tests, which are in agreement with expectations of the orientation-based unification model for quasars.

  17. A Compact Group of Galaxies at z = 2.48 Hosting an AGN-driven Outflow

    NASA Astrophysics Data System (ADS)

    Shih, Hsin-Yi; Stockton, Alan

    2015-12-01

    We present observations of a remarkable compact group of galaxies at z = 2.48. Four galaxies, all within 40 kpc of each other, surround a powerful high-redshift radio source. This group comprises two compact red passive galaxies and a pair of merging galaxies. One of the red galaxies, with an apparent stellar mass of 3.6 × 1011M⊙ and an effective radius of 470 pc, is one of the most extreme examples of a massive quiescent compact galaxy found so far. One of the pair of merging galaxies hosts the active galactic nucleus (AGN) producing the large powerful radio structure. The merger is massive and enriched, consistent with the mass-metallicity relation expected at this redshift. Close to the merging nuclei, the emission lines exhibit broad and asymmetric profiles that suggest outflows powered either by a very young expanding radio jet or by AGN radiation. At ≳50 kpc from the system, we found a fainter extended-emission region that may be a part of a radio-jet-driven outflow. Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. The work is also based, in part, on data collected at the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan, and on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciência, Tecnologia e Inovação (Brazil), and Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina).

  18. Spectroscopic identification of a redshift 1.55 supernova host galaxy from the Subaru Deep Field Supernova Survey

    NASA Astrophysics Data System (ADS)

    Frederiksen, Teddy F.; Graur, Or; Hjorth, Jens; Maoz, Dan; Poznanski, Dovi

    2014-03-01

    Context. The Subaru Deep Field (SDF) Supernova Survey discovered ten Type Ia supernovae (SNe Ia) in the redshift range 1.5 < z < 2.0, determined solely from photometric redshifts of the host galaxies. However, photometric redshifts might be biased, and the SN sample could be contaminated by active galactic nuclei (AGNs). Aims: We aim to obtain the first robust redshift measurement and classification of a z > 1.5 SDF SN Ia host galaxy candidate. Methods: We use the X-shooter (U-to-K-band) spectrograph on the Very Large Telescope to allow the detection of different emission lines in a wide spectral range. Results: We measure a spectroscopic redshift of 1.54563 ± 0.00027 of hSDF0705.25, consistent with its photometric redshift of 1.552 ± 0.018. From the strong emission-line spectrum we rule out AGN activity, thereby confirming the optical transient as a SN. The host galaxy follows the fundamental metallicity relation showing that the properties of this high-redshift SN Ia host galaxy is similar to other field galaxies. Conclusions: Spectroscopic confirmation of additional SDF SN hosts would be required to confirm the cosmic SN rate evolution measured in the SDF. Based on observations made with ESO telescopes at the La Silla Paranal Observatory under program ID 089.A-0739.

  19. Can supermassive black holes influence the evolution of their host galaxies?

    NASA Astrophysics Data System (ADS)

    Tombesi, F.; Cappi, M.; Reeves, J.; Braito, V.; Veilleux, S.; Reynolds, C.; Lobban, A.

    2016-06-01

    Powerful winds driven by active galactic nuclei (AGN) are often invoked to play a fundamental role in the evolution of both supermassive black holes (SMBHs) and their host galaxies, quenching star formation and explaining the tight SMBH-galaxy relations. A strong support of this "quasar mode" feedback came from the recent X-ray observation of a mildly relativistic accretion disk wind in an ultraluminous infrared galaxy and its connection with a large-scale molecular outflow observed in the IR with Herschel, suggesting a direct link between the SMBH and the gas out of which stars form. Spectroscopic observations, especially in the X-ray band, suggest that such accretion disk winds may be common in local AGN and quasars. However, their origin and characteristics are still not fully understood. Detailed theoretical models and simulations focused on radiation, magnetohydrodynamic (MHD) or a combination of these two processes, to investigate the possible acceleration mechanisms and dynamics of these winds. XMM-Newton provided a fundamental contribution to these studies and it will still provide the highest effective area in the critical Fe K band of the spectrum until the launch of Athena. Very important improvements are expected from the high energy resolution of the Hitomi X-ray Observatory.

  20. AN EXAMINATION OF THE OPTICAL SUBSTRUCTURE OF GALAXY CLUSTERS HOSTING RADIO SOURCES

    SciTech Connect

    Wing, Joshua D.; Blanton, Elizabeth L.

    2013-04-20

    Using radio sources from the Faint Images of the Radio Sky at Twenty-cm survey, and optical counterparts in the Sloan Digital Sky Survey, we have identified a large number of galaxy clusters. The radio sources within these clusters are driven by active galactic nuclei, and our cluster samples include clusters with bent, and straight, double-lobed radio sources. We also included a single-radio-component comparison sample. We examine these galaxy clusters for evidence of optical substructure, testing the possibility that bent double-lobed radio sources are formed as a result of large-scale cluster mergers. We use a suite of substructure analysis tools to determine the location and extent of substructure visible in the optical distribution of cluster galaxies, and compare the rates of substructure in clusters with different types of radio sources. We found no preference for significant substructure in clusters hosting bent double-lobed radio sources compared to those with other types of radio sources.

  1. Investigating the host galaxies of luminous AGN in the local universe with integral field spectroscopy

    NASA Astrophysics Data System (ADS)

    McElroy, Rebecca; Croom, Scott; Husemann, Bernd; Close AGN Reference Survey; SAMI Galaxy Survey

    2017-01-01

    This thesis investigates how galaxies and their super massive black holes coevolve. We use integral field spectroscopy to search for evidence of AGN feedback and triggering. We demonstrate that outflows are ubiquitous among luminous local type 2 AGN using observations from the AAT's SPIRAL instrument. Using multiple component Gaussian emission line decomposition we are able to disentangle the kinematic and ionisation properties of these winds. This allows us to argue that the outflows from these AGN are directly impacting the surrounding ISM within the galaxies. We search for evidence of AGN triggering using data from The Close AGN Reference Survey (CARS). CARS aims to provide a detailed multi-wavelength view of 40 nearby (0.01 < z < 0.06) unobscured AGN to study the link between AGN and their host galaxies. The primary CARS observations come from the MUSE integral field unit on the VLT, and complementary multi-wavelength observations have been approved from SOFIA, Chandra, VLA, HST, and others. We compare the stellar kinematics of active galaxies from CARS to similar inactive galaxies. We then use kinemetry to estimate the degree of dynamical disturbance, to determine whether active nuclei are preferentially hosted in dynamically disturbed or merging systems. Finally, we highlight the discovery of an AGN that has changed spectral type not once, but twice. So called ‘changing look’ AGN are an uncommon phenomenon, but twice changed AGN are much rarer. This AGN first transitioned from a narrow line AGN (type 2) to a broad line AGN (type 1) in the 1980s. It was recently observed as part of CARS. Examination of the MUSE data for this particular source showed that it no longer had the spectral features typical of a type 1 AGN. The continuum emission from the accretion disk was no longer visible and the broad lines were dramatically diminished. In this talk we describe the possible reasons for this change, supported by analysis of multi-epoch optical photometry and

  2. Extracting Host Galaxy Dispersion Measure and Constraining Cosmological Parameters using Fast Radio Burst Data

    NASA Astrophysics Data System (ADS)

    Yang, Yuan-Pei; Zhang, Bing

    2016-10-01

    The excessive dispersion measures (DMs) and high Galactic latitudes of fast radio bursts (FRBs) hint toward a cosmological origin of these mysterious transients. Methods of using measured DM and redshift z to study cosmology have been proposed, but one needs to assume a certain amount of DM contribution from the host galaxy ({{DM}}{HG}) in order to apply those methods. We introduce a slope parameter β (z)\\equiv d{ln}< {{DM}}{{E}}> /d{ln}z (where {{DM}}{{E}} is the observed DM subtracting the Galactic contribution), which can be directly measured when a sample of FRBs have z measured. We show that < {{DM}}{HG}> can be roughly inferred from β and the mean values, \\overline{< {{DM}}{{E}}> } and \\bar{z}, of the sample. Through Monte Carlo simulations, we show that the mean value of local host galaxy DM, < {{DM}}{HG,{loc}}> , along with other cosmological parameters (mass density {{{Ω }}}m in the ΛCDM model, and the IGM portion of the baryon energy density {{{Ω }}}b{f}{IGM}), can be independently measured through Markov Chain Monte Carlo fitting to the data.

  3. Hubble Space Telescope observations of the host galaxies and environments of calcium-rich supernovae

    NASA Astrophysics Data System (ADS)

    Lyman, J. D.; Levan, A. J.; James, P. A.; Angus, C. R.; Church, R. P.; Davies, M. B.; Tanvir, N. R.

    2016-05-01

    Calcium-rich supernovae (SNe) represent a significant challenge for our understanding of the fates of stellar systems. They are less luminous than other SN types and they evolve more rapidly to reveal nebular spectra dominated by strong calcium lines with weak or absent signatures of other intermediate- and iron-group elements, which are seen in other SNe. Strikingly, their explosion sites also mark them out as distinct from other SN types. Their galactocentric offset distribution is strongly skewed to very large offsets (˜1/3 are offset >20 kpc), meaning they do not trace the stellar light of their hosts. Many of the suggestions to explain this extreme offset distribution have invoked the necessity for unusual formation sites such as globular clusters or dwarf satellite galaxies, which are therefore difficult to detect. Building on previous work attempting to detect host systems of nearby Ca-rich SNe, we here present Hubble Space Telescope imaging of five members of the class - three exhibiting large offsets and two coincident with the disc of their hosts. We find no underlying sources at the explosion sites of any of our sample. Combining with previous work, the lack of a host system now appears to be a ubiquitous feature amongst Ca-rich SNe. In this case the offset distribution is most readily explained as a signature of high-velocity progenitor systems that have travelled significant distances before exploding.

  4. Supermassive black holes and their host galaxies. I. Bulge luminosities from dedicated near-infrared data

    SciTech Connect

    Läsker, Ronald; Van de Ven, Glenn; Ferrarese, Laura

    2014-01-01

    In an effort to secure, refine, and supplement the relation between central supermassive black hole masses, M {sub •}, and the bulge luminosities of their host galaxies, L {sub bul}, we obtained deep, high spatial resolution K-band images of 35 nearby galaxies with securely measured M {sub •}, using the wide-field WIRCam imager at the Canada-France-Hawaii-Telescope. A dedicated data reduction and sky subtraction strategy was adopted to estimate the brightness and structure of the sky, a critical step when tracing the light distribution of extended objects in the near-infrared. From the final image product, bulge and total magnitudes were extracted via two-dimensional profile fitting. As a first order approximation, all galaxies were modeled using a simple Sérsic-bulge+exponential-disk decomposition. However, we found that such models did not adequately describe the structure that we observed in a large fraction of our sample galaxies which often include cores, bars, nuclei, inner disks, spiral arms, rings, and envelopes. In such cases, we adopted profile modifications and/or more complex models with additional components. The derived bulge magnitudes are very sensitive to the details and number of components used in the models, although total magnitudes remain almost unaffected. Usually, but not always, the luminosities and sizes of the bulges are overestimated when a simple bulge+disk decomposition is adopted in lieu of a more complex model. Furthermore, we found that some spheroids are not well fit when the ellipticity of the Sérsic model is held fixed. This paper presents the details of the image processing and analysis, while we discuss how model-induced biases and systematics in bulge magnitudes impact the M {sub •}-L {sub bul} relation in a companion paper.

  5. COSMIC EVOLUTION OF BLACK HOLES AND SPHEROIDS. V. THE RELATION BETWEEN BLACK HOLE MASS AND HOST GALAXY LUMINOSITY FOR A SAMPLE OF 79 ACTIVE GALAXIES

    SciTech Connect

    Park, Daeseong; Woo, Jong-Hak; Bennert, Vardha N.; Treu, Tommaso; Auger, Matthew W.; Malkan, Matthew A. E-mail: woo@astro.snu.ac.kr E-mail: vbennert@calpoly.edu E-mail: malkan@astro.ucla.edu

    2015-02-01

    We investigate the cosmic evolution of the black hole (BH) mass-bulge luminosity relation using a sample of 52 active galaxies at z ∼ 0.36 and z ∼ 0.57 in the BH mass range of 10{sup 7.4}-10{sup 9.1} M {sub ☉}. By consistently applying multicomponent spectral and structural decomposition to high-quality Keck spectra and high-resolution Hubble Space Telescope images, BH masses (M {sub BH}) are estimated using the Hβ broad emission line combined with the 5100 Å nuclear luminosity, and bulge luminosities (L {sub bul}) are derived from surface photometry. Comparing the resulting M {sub BH} – L {sub bul} relation to local active galaxies and taking into account selection effects, we find evolution of the form M {sub BH}/L {sub bul}∝(1 + z){sup γ} with γ = 1.8 ± 0.7, consistent with BH growth preceding that of the host galaxies. Including an additional sample of 27 active galaxies with 0.5 < z < 1.9 taken from the literature and measured in a consistent way, we obtain γ = 0.9 ± 0.7 for the M {sub BH} – L {sub bul} relation and γ = 0.4 ± 0.5 for the M {sub BH}-total host galaxy luminosity (L {sub host}) relation. The results strengthen the findings from our previous studies and provide additional evidence for host galaxy bulge growth being dominated by disk-to-bulge transformation via minor mergers and/or disk instabilities.

  6. The influence of host galaxy morphology on the properties of Type Ia supernovae from the JLA compilation

    NASA Astrophysics Data System (ADS)

    Henne, V.; Pruzhinskaya, M. V.; Rosnet, P.; Léget, P.-F.; Ishida, E. E. O.; Ciulli, A.; Gris, P.; Says, L.-P.; Gangler, E.

    2017-02-01

    The observational cosmology with distant Type Ia supernovae (SNe) as standard candles claims that the Universe is in accelerated expansion, caused by a large fraction of dark energy. In this paper we investigate the SN Ia environment, studying the impact of the nature of their host galaxies on the Hubble diagram fitting. The supernovae (192 SNe) used in the analysis were extracted from Joint-Light-curves-Analysis (JLA) compilation of high-redshift and nearby supernovae which is the best one to date. The analysis is based on the empirical fact that SN Ia luminosities depend on their light curve shapes and colors. We confirm that the stretch parameter of Type Ia supernovae is correlated with the host galaxy type. The supernovae with lower stretch are hosted mainly in elliptical and lenticular galaxies. No significant correlation between SN Ia colour and host morphology was found.   We also examine how the luminosities of SNe Ia change depending on host galaxy morphology after stretch and colour corrections. Our results show that in old stellar populations and low dust environments, the supernovae are slightly fainter. SNe Ia in elliptical and lenticular galaxies have a higher α (slope in luminosity-stretch) and β (slope in luminosity-colour) parameter than in spirals. However, the observed shift is at the 1-σ uncertainty level and, therefore, can not be considered as significant.   We confirm that the supernova properties depend on their environment and that the incorporation of a host galaxy term into the Hubble diagram fit is expected to be crucial for future cosmological analyses.

  7. 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

  8. The metallicity dependence of the long-duration gamma-ray burst rate from host galaxy luminosities

    NASA Astrophysics Data System (ADS)

    Wolf, Christian; Podsiadlowski, Philipp

    2007-03-01

    We investigate the difference between the host galaxy properties of core-collapse supernovae (CC SNe) and long-duration gamma-ray bursts (LGRBs), and quantify a possible metallicity dependence of the efficiency of producing LGRBs. We use a sample of 16 CC SNe and 16 LGRBs from Fruchter et al. which have similar redshift distributions to eliminate galaxy evolution biases. We make a forward prediction of their host galaxy luminosity distributions from the overall cosmic metallicity distribution of star formation. The latter is based on luminosity functions, star formation rates (SFRs) and luminosity-metallicity (L-Z) relations of galaxies. This approach is supported by the finding that LGRB hosts follow the L-Z relations of star-forming galaxies. We then compare predictions for metallicity-dependent event efficiencies with the observed host data. We find that ultraviolet-based SFR estimates predict the host distribution of CC SNe perfectly well in a metallicity-independent form. In contrast, LGRB hosts are on average fainter by one magnitude, almost as faint as the Large Magellanic Cloud. Assuming this to be a metallicity effect, the present data are insufficient to discriminate between a sharp cut-off and a soft decrease in efficiency towards higher metallicity. For a sharp cut-off, however, we find a best value for the cut-off metallicity, as reflected in the oxygen abundance, 12 + log(O/H)lim ~= 8.7 +/- 0.3 at 95 per cent confidence including systematic uncertainties, in the calibration of Asplund, Grevesse & Sauval. This value is somewhat lower than the traditionally quoted value for the Sun, but is comparable to the revised solar oxygen abundance. LGRB models that require sharp metallicity cut-offs well below approximately one-half the revised solar metallicity appear to be effectively ruled out, as they would require fainter LGRB hosts than those that are observed. We also discuss the likely implications of the still ongoing metallicity `calibration debate'.

  9. The host galaxies of ultra hard X-ray selected AGN

    NASA Astrophysics Data System (ADS)

    Koss, Michael J.

    One of the great mysteries surrounding active galactic nuclei (AGN) is their triggering mechanism. Since the discovery that almost all massive galaxies host nuclear supermassive black holes, it has become clear that a trigger mechanism is required to 'turn on' and continue to fuel the central black hole. While it is established that accretion processes are responsible for the energy emitted, the source of the accreting material is still controversial. Furthermore, the energy input from phases of black hole growth is thought to be a key regulator in the formation of galaxies and the establishment of various scaling relations. Theorists often invoke galaxy mergers as the violent mechanism to drive gas into the central regions and ignite luminous quasars, but among more common moderate luminosity AGN, there has been great controversy whether secular processes or mergers dominate AGN fueling. A survey in the ultra hard X-ray band (14--195 keV) is an important new way to answer the fundamental question of AGN fueling. This method is independent of selection effects such as dust extinction and obscuration that plague surveys at other wavelengths because of the ability of the primary continuum to easily pass through large columns of obscuring gas and dust (<10 24 cm-2). In this PhD, we have assembled the largest sample of ultra hard X-ray selected AGN with host galaxy optical data to date, with 185 nearby (z<0.05), moderate luminosity AGN from the Swift BAT sample. We find that these AGN show much higher rates of both mergers and massive spirals suggesting both mergers and accretion of cold gas in late type systems are important in AGN fueling. We also find that the most common AGN survey technique, optical line diagnostics, is heavily biased against finding AGN in mergers or spirals. Finally, in agreement with the merger driven AGN link, we find that dual AGN systems may be more common than current observation suggest since some of them are only detected using high

  10. GALAXY CLUSTERS IN THE LINE OF SIGHT TO BACKGROUND QUASARS. III. MULTI-OBJECT SPECTROSCOPY

    SciTech Connect

    Andrews, H.; Barrientos, L. F.; Padilla, N.; Lacerna, I.; Lopez, S.; Lira, P.; Maureira, M. J.; Gilbank, D. G.; Ellingson, E.; Gladders, M. D.; Yee, H. K. C.

    2013-09-01

    We present Gemini/GMOS-S multi-object spectroscopy of 31 galaxy cluster candidates at redshifts between 0.2 and 1.0 and centered on QSO sight lines taken from Lopez et al. The targets were selected based on the presence of an intervening Mg II absorption system at a similar redshift to that of a galaxy cluster candidate lying at a projected distance <2 h{sub 71}{sup -1} Mpc from the QSO sight line (a {sup p}hotometric hit{sup )}. The absorption systems span rest-frame equivalent widths between 0.015 and 2.028 A. Our aim was three-fold: (1) to identify the absorbing galaxies and determine their impact parameters, (2) to confirm the galaxy cluster candidates in the vicinity of each quasar sightline, and (3) to determine whether the absorbing galaxies reside in galaxy clusters. In this way, we are able to characterize the absorption systems associated with cluster members. Our main findings are as follows. (1) We identified 10 out of 24 absorbing galaxies with redshifts between 0.2509 {<=} z{sub gal} {<=} 1.0955, up to an impact parameter of 142 h{sub 71}{sup -1} kpc and a maximum velocity difference of 280 km s{sup -1}. (2) We spectroscopically confirmed 20 out of 31 cluster/group candidates, with most of the confirmed clusters/groups at z < 0.7. This relatively low efficiency results from the fact that we centered our observations on the QSO location, and thus occasionally some of the cluster centers were outside the instrument field of view. (3) Following from the results above, we spectroscopically confirmed of 10 out of 14 photometric hits within {approx}650 km s{sup -1} from galaxy clusters/groups, in addition to two new ones related to galaxy group environments. These numbers imply efficiencies of 71% in finding such systems with MOS spectroscopy. This is a remarkable result since we defined a photometric hit as those cluster-absorber pairs having a redshift difference {Delta}z = 0.1. The general population of our confirmed absorbing galaxies have luminosities

  11. GEMINI 3D spectroscopy of BAL + IR + FeII QSOs - I. Decoupling the BAL, QSO, starburst, NLR, supergiant bubbles and galactic wind in Mrk 231

    NASA Astrophysics Data System (ADS)

    Lipari, S.; Sanchez, S. F.; Bergmann, M.; Terlevich, R.; Garcia-Lorenzo, B.; Punsly, B.; Mediavilla, E.; Taniguchi, Y.; Ajiki, M.; Zheng, W.; Acosta, J.; Jahnke, K.

    2009-02-01

    In this paper we present the first results of a study of BAL QSOs (at low and high redshift), based on very deep Gemini GMOS integral field spectroscopy. In particular, the results obtained for the nearest BAL IR-QSO Mrk 231 are presented. For the nuclear region of Mrk 231, the QSO and host galaxy components were modelled, using a new technique of decoupling 3D spectra. From this study, the following main results were found: (i) in the pure host galaxy spectrum an extreme nuclear starburst component was clearly observed, as a very strong increase in the flux, at the blue wavelengths; (ii) the BAL system I is observed in the spectrum of the host galaxy; (iii) in the clean/pure QSO emission spectrum, only broad lines were detected. 3D GMOS individual spectra (specially in the near-infrared CaII triplet) and maps confirm the presence of an extreme and young nuclear starburst (8 < age < 15 Myr), which was detected in a ring or toroid with a radius r = 0.3arcsec ~ 200 pc, around the core of the nucleus. The extreme continuum blue component was detected only to the south of the core of the nucleus. This area is coincident with the region where we previously suggested that the galactic wind is cleaning the nuclear dust. Very deep 3D spectra and maps clearly show that the BAL systems I and II - in the strong `absorption lines' NaIDλ5889-95 and CaII Kλ3933 - are extended (reaching ~1.4-1.6 arcsec ~ 1.2-1.3 kpc, from the nucleus) and clearly elongated at the position angle (PA) close to the radio jet PA, which suggest that the BAL systems I and II are `both' associated with the radio jet. The physical properties of the four expanding nuclear bubbles were analysed, using the GMOS 3D spectra and maps. In particular, we found strong multiple LINER/OF emission-line systems and Wolf-Rayet features in the main knots of the more external super bubble S1 (r = 3.0 kpc). The kinematics of these knots - and the internal bubbles - suggest that they are associated with an area of

  12. Galaxies

    SciTech Connect

    Not Available

    1981-01-01

    Normal galaxies, radio galaxies, and Seyfert galaxies are considered. The large magellanic cloud and the great galaxy in Andromedia are highlighted. Quasars and BL lacertae objects are also discussed and a review of the spectral observations of all of these galaxies and celestial objects is presented.

  13. The host galaxies and explosion sites of long-duration gamma ray bursts: Hubble Space Telescope near-infrared imaging

    NASA Astrophysics Data System (ADS)

    Lyman, J. D.; Levan, A. J.; Tanvir, N. R.; Fynbo, J. P. U.; McGuire, J. T. W.; Perley, D. A.; Angus, C. R.; Bloom, J. S.; Conselice, C. J.; Fruchter, > A. S.; Hjorth, J.; Jakobsson, P.; Starling, R. L. C.

    2017-01-01

    We present the results of a Hubble Space Telescope WFC3/F160W SNAPSHOT survey of the host galaxies of 39 long-duration gamma-ray bursts (LGRBs) at z < 3. We have non-detections of hosts at the locations of 4 bursts. Sufficient accuracy to astrometrically align optical afterglow images and determine the location of the LGRB within its host was possible for 31/35 detected hosts. In agreement with other work, we find the luminosity distribution of LGRB hosts is significantly fainter than that of a star formation rate-weighted field galaxy sample over the same redshift range, indicating LGRBs are not unbiasedly tracing the star formation rate. Morphologically, the sample of LGRB hosts are dominated by spiral-like or irregular galaxies. We find evidence for evolution of the population of LGRB hosts towards lower-luminosity, higher concentrated hosts at lower redshifts. Their half-light radii are consistent with other LGRB host samples where measurements were made on rest-frame UV observations. In agreement with recent work, we find their 80 per cent enclosed flux radii distribution to be more extended than previously thought, making them intermediate between core-collapse supernova (CCSN) and super-luminous supernova (SLSN) hosts. The galactocentric projected-offset distribution confirms LGRBs as centrally concentrated, much more so than CCSNe and similar to SLSNe. LGRBs are strongly biased towards the brighter regions in their host light distributions, regardless of their offset. We find a correlation between the luminosity of the LGRB explosion site and the intrinsic column density, NH, towards the burst.

  14. The obscured hyper-energetic GRB 120624B hosted by a luminous compact galaxy at z = 2.20

    NASA Astrophysics Data System (ADS)

    de Ugarte Postigo, A.; Campana, S.; Thöne, C. C.; D'Avanzo, P.; Sánchez-Ramírez, R.; Melandri, A.; Gorosabel, J.; Ghirlanda, G.; Veres, P.; Martín, S.; Petitpas, G.; Covino, S.; Fynbo, J. P. U.; Levan, A. J.

    2013-09-01

    Context. Gamma-ray bursts (GRBs) are the most luminous explosions that we can witness in the Universe. Studying the most extreme cases of these phenomena allows us to constrain the limits for the progenitor models. Aims: In this Letter, we study the prompt emission, afterglow, and host galaxy of GRB 120624B, one of the brightest GRBs detected by Fermi, to derive the energetics of the event and characterise the host galaxy in which it was produced. Methods: Following the high-energy detection we conducted a multi-wavelength follow-up campaign, including near-infrared imaging from HAWKI/VLT, optical from OSIRIS/GTC, X-ray observations from the Chandra X-ray Observatory and at submillimetre/millimetre wavelengths from SMA. Optical/NIR spectroscopy was performed with X-shooter/VLT. Results: We detect the X-ray and NIR afterglow of the burst and determine a redshift of z = 2.1974 ± 0.0002 through identification of emission lines of [O ii], [O iii] and H-α from the host galaxy of the GRB. This implies an energy release of Eiso,γ = (3.0 ± 0.2) × 1054 erg, amongst the most luminous ever detected. The observations of the afterglow indicate high obscuration with AV > 1.5. The host galaxy is compact, with R1/2 < 1.6 kpc, but luminous, at L ~ 1.5 L∗ and has a star formation rate of 91 ± 6 M⊙/yr as derived from Hα. Conclusions: As for other highly obscured GRBs, GRB 120624B is hosted by a luminous galaxy, which we also prove to be compact, with very intense star formation. It is one of the most luminous host galaxies associated with a GRB, showing that the host galaxies of long GRBs are not always blue dwarf galaxies, as previously thought. Based on observations collected at the European Southern Observatory, Chile, with programmes 089.D-0256 and 090.D-0667, at the Gran Telescopio Canarias with programmes GTC49-12A and GTC58-12B, at the Submillimeter Array with programme 2012A-S001, at CAHA with programme F13-3.5-031, at Liverpool Telescope with programme CL13A03

  15. A REFINED QSO SELECTION METHOD USING DIAGNOSTICS TESTS: 663 QSO CANDIDATES IN THE LARGE MAGELLANIC CLOUD

    SciTech Connect

    Kim, Dae-Won; Protopapas, Pavlos; Trichas, Markos; Alcock, Charles; Rowan-Robinson, Michael; Khardon, Roni; Byun, Yong-Ik

    2012-03-10

    We present 663 QSO candidates in the Large Magellanic Cloud (LMC) selected using multiple diagnostics. We started with a set of 2566 QSO candidates selected using the methodology presented in our previous work based on time variability of the MACHO LMC light curves. We then obtained additional information for the candidates by crossmatching them with the Spitzer SAGE, the Two Micron All Sky Survey, the Chandra, the XMM, and an LMC UBVI catalog. Using this information, we specified six diagnostic features based on mid-IR colors, photometric redshifts using spectral energy distribution template fitting, and X-ray luminosities in order to further discriminate high-confidence QSO candidates in the absence of spectra information. We then trained a one-class Support Vector Machine model using the diagnostics features of the confirmed 58 MACHO QSOs. We applied the trained model to the original candidates and finally selected 663 high-confidence QSO candidates. Furthermore, we crossmatched these 663 QSO candidates with the newly confirmed 151 QSOs and 275 non-QSOs in the LMC fields. On the basis of the counterpart analysis, we found that the false positive rate is less than 1%.

  16. Survey incompleteness and the evolution of the QSO luminosity function

    NASA Technical Reports Server (NTRS)

    Majewski, Steven R.; Munn, Jeffrey A.; Kron, Richard G.; Bershady, Matthew A.; Smetanka, John J.; Koo, David C.

    1993-01-01

    We concentrate on a type of QSO survey which depends on selecting QSO candidates based on combinations of colors. Since QSO's have emission lines and power-law continua, they are expected to yield broadband colors unlike those of stellar photospheres. Previously, the fraction of QSO's expected to be hiding (unselected) within the locus of stellar (U-J, J-F) colors was estimated at about 15 percent. We have now verified that the KK88 survey is at least 11 percent incomplete, but have determined that it may be as much as 34 percent incomplete. The 'missing' QSO's are expected to be predominantly at z less than or = 2.2. We have studied the proper motion and variability properties of all stellar objects with J less than or = 22.5 or F less than or = 21.5 in the SA 57 field which has previously been surveyed with a multicolor QSO search by KK88.

  17. THE ACS VIRGO CLUSTER SURVEY. XVII. THE SPATIAL ALIGNMENT OF GLOBULAR CLUSTER SYSTEMS WITH EARLY-TYPE HOST GALAXIES

    SciTech Connect

    Wang Qiushi; Peng, Eric W.; Blakeslee, John P.; Cote, Patrick; Ferrarese, Laura; Jordan, Andres; Mei, Simona; West, Michael J.

    2013-06-01

    We study the azimuthal distribution of globular clusters (GCs) in early-type galaxies and compare them to their host galaxies using data from the ACS Virgo Cluster Survey. We find that in host galaxies with visible elongation ({epsilon} > 0.2) and intermediate to high luminosities (M{sub z} < -19), the GCs are preferentially aligned along the major axis of the stellar light. The red (metal-rich) GC subpopulations show strong alignment with the major axis of the host galaxy, which supports the notion that these GCs are associated with metal-rich field stars. The metal-rich GCs in lenticular galaxies show signs of being more strongly associated with disks rather than bulges. Surprisingly, we also find that the blue (metal-poor) GCs can also show the same correlation. If the metal-poor GCs are part of the early formation of the halo and built up through mergers, then our results support a picture where halo formation and merging occur anisotropically, and that the present-day major axis is an indicator of the preferred merging axis.

  18. INSIGHT INTO ACTIVE GALACTIC NUCLEUS AND HOST GALAXY CO-EVOLUTION FROM HARD X-RAY EMISSION

    SciTech Connect

    Wang, J.; Zhou, X. L.; Wei, J. Y.

    2013-05-10

    We study the issue of active galactic nucleus (AGN) and host co-evolution by focusing on the correlation between the hard X-ray emission from central AGNs and the stellar populations of the host galaxies. Focusing on galaxies with strong H{alpha} line emission (EW(H{alpha}) > 5 A), both X-ray and optical spectral analyses are performed on 67 (partially) obscured AGNs that are selected from the XMM-Newton 2XMMi/SDSS-DR7 catalog originally cross-matched by Pineau et al. The sample allows us to study central AGN activity and host galaxy activity directly and simultaneously in individual objects. Combining the spectral analysis in both bands reveals that the older the stellar population of the host galaxy, the harder the X-ray emission will be, which was missed in our previous study where ROSAT hardness ratios were used. By excluding the contamination from host galaxies and from jet beaming emission, the correlation indicates that Compton cooling in the accretion disk corona decreases with the mean age of the stellar population. We argue that this correlation is related to the correlation of L/L{sub Edd} with the host stellar population. In addition, the [O I]/H{alpha} and [S II]/H{alpha} narrow-line ratios are identified to correlate with the spectral slope in hard X-rays, which can be inferred from the currently proposed evolution of the X-ray emission because of the confirmed tight correlations between the two line ratios and stellar population age.

  19. Revisiting the Abundance Gradient in the Maser Host Galaxy NGC 4258

    NASA Astrophysics Data System (ADS)

    Bresolin, Fabio

    2011-03-01

    New spectroscopic observations of 36 H II regions in NGC 4258 obtained with the Gemini telescope are combined with existing data from the literature to measure the radial oxygen abundance gradient in this galaxy. The [O III]λ4363 auroral line was detected in four of the outermost targets (17-22 kpc from the galaxy center), allowing a determination of the electron temperature Te of the ionized gas. From the use of different calibrations of the R 23 abundance indicator, an oxygen abundance gradient of approximately -0.012 ± 0.002 dex kpc-1 is derived. Such a shallow gradient, combined with the difference in the distance moduli measured from the Cepheid period-luminosity relation by Macri et al. between two distinct fields in NGC 4258, would yield an unrealistically strong effect of metallicity on the Cepheid distances. This strengthens the suggestion that systematic biases might affect the Cepheid distance of the outer field. Evidence for a similar effect in the differential study of M33 by Scowcroft et al. is presented. A revision of the transformation between strong-line and Te -based abundances in Cepheid-host galaxies is discussed. In the Te abundance scale, the oxygen abundance of the inner field of NGC 4258 is found to be comparable with the LMC value. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Science and Technology Facilities Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciência e Tecnologia (Brazil) and Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina).

  20. SUPPRESSION OF STAR FORMATION IN THE HOSTS OF LOW-EXCITATION RADIO GALAXIES

    SciTech Connect

    Pace, Cameron; Salim, Samir E-mail: salims@indiana.edu

    2016-02-10

    The feedback from radio-loud active galactic nuclei (R-AGNs) may help maintain low star-formation (SF) rates in their early-type hosts, but the observational evidence for this mechanism has been inconclusive. We study systematic differences of aggregate spectral energy distributions (SEDs) of various subsets of ∼4000 low-redshift R-AGNs from Best and Heckman with respect to (currently) inactive control samples selected to have matching redshift, stellar mass, population age, axis ratio, and environment. Aggregate SEDs, ranging from the ultraviolet (UV) through mid-infrared (mid-IR, 22 μm), were constructed using a Bayesian method that eliminates biases from non-detections in Galaxy Evolution Explorer and Wide-field Infrared Survey Explorer. We study rare high-excitation sources separately from low-excitation ones, which we split by environment and host properties. We find that both the UV and mid-IR emission of non-cluster R-AGNs (80% of sample) are suppressed by ∼0.2 dex relative to that of the control group, especially for moderately massive galaxies (log M{sub *} ≲ 11). The difference disappears for high-mass R-AGNs and for R-AGNs in clusters, where other, non-AGN quenching/maintenance mechanisms may dominate, or where the suppression of SF due to AGNs may persist between active phases of the central engine, perhaps because of the presence of a hot gaseous halo storing AGN energy. High-excitation (high accretion rate) sources, which make up 2% of the R-AGN sample, do not show any evidence of SF suppression (their UV is the same as in controls), but they exhibit a strong mid-IR excess due to AGN dust heating.

  1. A deep search for the host galaxies of gamma-ray bursts with no detected optical afterglow

    NASA Astrophysics Data System (ADS)

    Rossi, A.; Klose, S.; Ferrero, P.; Greiner, J.; Arnold, L. A.; Gonsalves, E.; Hartmann, D. H.; Updike, A. C.; Kann, D. A.; Krühler, T.; Palazzi, E.; Savaglio, S.; Schulze, S.; Afonso, P. M. J.; Amati, L.; Castro-Tirado, A. J.; Clemens, C.; Filgas, R.; Gorosabel, J.; Hunt, L. K.; Küpcü Yoldaş, A.; Masetti, N.; Nardini, M.; Nicuesa Guelbenzu, A.; Olivares, F. E.; Pian, E.; Rau, A.; Schady, P.; Schmidl, S.; Yoldaş, A.; de Ugarte Postigo, A.

    2012-09-01

    Context. Gamma-ray bursts (GRBs) can provide information about star formation at high redshifts. Even in the absence of a bright optical/near-infrared/radio afterglow, the high detection rate of X-ray afterglows by Swift/XRT and its localization precision of 2-3 arcsec facilitates the identification and the study of GRB host galaxies. Aims: We focus on the search for the host galaxies of 17 bursts with arcsec-sized XRT error circles but no detected long-wavelength afterglow, in spite of their deep and rapid follow-up observations. Three of these events can also be classified as truly dark bursts, i.e., the observed upper limit on the optical flux of the afterglow was less than expected based on the measured X-ray flux. Our goals are to identify the GRB host galaxy candidates and characterize their phenomenological parameters. Methods: Our study is based on deep RC and Ks-band observations performed with FORS1, FORS2, VIMOS, ISAAC, and HAWK-I at the ESO/VLT, partly supported by observations with the seven-channel imager GROND at the 2.2-m telescope on La Silla, and supplemented by observations with NEWFIRM at the 4-m telescope on Kitt Peak. To be conservative, we searched for host galaxy candidates within an area of twice the radius of each associated 90% c.l. Swift/XRT error circle. Results: For 15 of the 17 bursts, we find at least one galaxy within the searching area, and in the remaining two cases only a deep upper limit to RC and Ks can be provided. In seven cases, we discover extremely red objects in the error circles, at least four of which might be dust-enshrouded galaxies. The most remarkable case is the host of GRB 080207, which has a color of (RC - Ks)AB ~ 4.7 mag, and is one of the reddest galaxies ever associated with a GRB. As a by-product of our study we identify the optical afterglow of GRB 070517. Conclusions: Only a minority of optically dim afterglows are due to Lyman dropout (≲ 1/3). Extinction by dust in the host galaxies might explain all

  2. AEGIS: THE NATURE OF THE HOST GALAXIES OF LOW-IONIZATION OUTFLOWS AT z < 0.6

    SciTech Connect

    Sato, Taro; Martin, Crystal L.; Noeske, Kai G.; Koo, David C.

    2009-05-01

    We report on a signal-to-noise (S/N) limited search for low-ionization gas outflows in the spectra of the 0.11 < z < 0.54 objects in the Extended Groth Strip portion of the DEEP2 survey. Doppler shifts from the host galaxy redshifts are systematically searched for in the Na I {lambda} 5890, 96 doublet (Na I D). Although the spectral resolution and S/N limit us to study the interstellar gas kinematics from fitting a single doublet component to each observed Na I D profile, the typical outflow often seen in local luminous-infrared galaxies (LIRGs) should be detected at {approx}> 6{sigma} in absorption equivalent width down to the survey limiting S/N ({approx}5 pixel{sup -1}) in the continuum around Na I D. The detection rate of LIRG-like outflow clearly shows an increasing trend with star-forming activity and infrared luminosity. However, by virtue of not selecting our sample on star formation, we also find a majority of outflows in galaxies on the red sequence in the rest-frame (U - B, M{sub B} ) color-magnitude diagram. Most of these red-sequence galaxies hosting outflows are of early-type morphology and show the sign of recent star formation in their UV-optical colors; some show enhanced Balmer H{beta} absorption lines indicative of poststarburst as well as high dust extinction. These findings demonstrate that outflows outlive starbursts and suggest that galactic-scale outflows play a role in quenching star formation in the host galaxies on their way to the red sequence. The fate of relic winds, as well as the observational constraints on gaseous feedback models, may be studied in galaxies during their poststarburst phase. We also note the presence of inflow candidates in red, early-type galaxies, some with signs of active galactic nuclei/LINERs but little evidence for star formation.

  3. The Contribution of Host Galaxies to the Infrared Energy Output of z ≳ 5.0 Quasars

    NASA Astrophysics Data System (ADS)

    Lyu, Jianwei; Rieke, G. H.; Alberts, Stacey

    2016-01-01

    The infrared spectral energy distributions of z ≳ 5 quasars can be reproduced by combining a low-metallicity galaxy template with a standard active galactic nucleus (AGN) template. The host galaxy is represented by Haro 11, a compact, moderately low metallicity, starbursting galaxy that shares typical features of high-z galaxies. For the vast majority of z ≳ 5 quasars, the AGN contribution is well modeled by a standard empirical template with the contamination of star formation in the infrared subtracted. Together, these two templates can separate the contributions from the host galaxy and the AGN even in the case of limited data points, given that this model has only two free parameters. Using this method, we reanalyze 69 z ≳ 5 quasars with extensive Herschel observations and derive their AGN luminosities [LAGN = (0.78{--}27.4)× {10}13 {L}⊙ ], infrared luminosities from star formation [{L}{{SF,IR}}\\quad ≲ (1.5{--}25.7)× {10}12 {L}⊙ ], and corresponding star formation rates ({{SFR}}\\quad ≲ 290{--}2650{M}⊙ {{{yr}}}-1). The average infrared luminosity from star formation and the average total AGN luminosity of the z ≳ 5 quasar sample follow the correlation defined by quasars at z < 2.6. We assume that these quasar host galaxies maintain a constant average SFR (˜620 M⊙ yr-1) during their mass assembly and estimate the stellar mass that could form prior to z ˜ 5-6 to be < {M}*> ˜ (3{--}5)× {10}11{M}⊙ . Combining with the black hole (BH) mass measurements, this stellar mass is adequate to establish a BH-galaxy mass ratio {M}{{BH}}/{M}* at 0.1%-1%, consistent with the local relation.

  4. Evidence of suppression of star formation by quasar-driven winds in gas-rich host galaxies at z < 1?

    NASA Astrophysics Data System (ADS)

    Wylezalek, Dominika; Zakamska, Nadia L.

    2016-10-01

    Feedback from active galactic nuclei (AGN) is widely considered to be the main driver in regulating the growth of massive galaxies through heating or driving gas out of the galaxy, preventing further increase in stellar mass. Observational proof for this scenario has, however, been scarce. We have assembled a sample of 132 radio-quiet type-2 and red AGN at 0.1 < z < 1. We measure the kinematics of the AGN-ionized gas, the host galaxies' stellar masses and star formation rates (SFRs) and investigate the relationships between AGN luminosities, specific star formation rates (sSFRs) and outflow strengths W90 - the 90 per cent velocity width of the [O III]λ5007Å line power and a proxy for the AGN-driven outflow speed. Outflow strength is independent of sSFR for AGN selected on their mid-IR luminosity, in agreement with previous work demonstrating 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 W90 and sSFR in the AGN hosts with the highest SFRs, i.e. with the highest gas content, where presumably the coupling of the AGN-driven wind to the gas is strongest. This implies that AGN with strong outflow signatures are hosted in galaxies that are more `quenched' than galaxies with weaker outflow signatures. Despite the galaxies' high SFRs, we demonstrate that the outflows are not star formation driven but indeed due to AGN powering. This observation is consistent with the AGN having a net suppression, `negative' impact, through feedback on the galaxies' star formation history.

  5. Attenuation of TeV γ-rays by the starlight photon field of the host galaxy

    NASA Astrophysics Data System (ADS)

    Zacharias, Michael; Chen, Xuhui; Wagner, Stefan J.

    2017-03-01

    The absorption of TeV γ-ray photons produced in relativistic jets by surrounding soft photon fields is a long-standing problem of jet physics. In some cases, the most likely emission site close to the central black hole is ruled out because of the high opacity caused by strong optical and infrared photon sources, such as the broad-line region. Mostly neglected for jet modelling is the absorption of γ-rays in the starlight photon field of the host galaxy. Analysing the absorption for arbitrary locations and observation angles of the γ-ray emission site within the host galaxy, we find that the distance to the galaxy centre, the observation angle, and the distribution of starlight in the galaxy are crucial for the amount of absorption. We derive the absorption value for a sample of 20 TeV-detected blazars with a redshift zr < 0.2. The absorption value of the γ-ray emission located in the galaxy centre may be as high as 20 per cent, with an average value of 6 per cent. This is important in order to determine the intrinsic blazar parameters. We see no significant trends in our sample between the degree of absorption and host properties, such as starlight emissivity, galactic size, half-light radius, and redshift. While the uncertainty of the spectral properties of the extragalactic background light exceeds the effect of absorption by stellar light from the host galaxy in distant objects, the latter is a dominant effect in nearby sources. It may also be revealed in a differential comparison of sources with similar redshifts.

  6. Host galaxies of luminous z ∼ 0.6 quasars: major mergers are not prevalent at the highest AGN luminosities

    NASA Astrophysics Data System (ADS)

    Villforth, C.; Hamilton, T.; Pawlik, M. M.; Hewlett, T.; Rowlands, K.; Herbst, H.; Shankar, F.; Fontana, A.; Hamann, F.; Koekemoer, A.; Pforr, J.; Trump, J.; Wuyts, S.

    2017-04-01

    Galaxy interactions are thought to be one of the main triggers of active galactic nuclei (AGN), especially at high luminosities, where the accreted gas mass during the AGN lifetime is substantial. Evidence for a connection between mergers and AGN, however, remains mixed. Possible triggering mechanisms remain particularly poorly understood for luminous AGN, which are thought to require triggering by major mergers, rather than secular processes. We analyse the host galaxies of a sample of 20 optically and X-ray selected luminous AGN (log(Lbol [erg s-1]) > 45) at z ∼ 0.6 using Hubble Space Telescope Wide Field Camera 3 data in the F160W/H band. 15/20 sources have resolved host galaxies. We create a control sample of mock AGN by matching the AGN host galaxies to a control sample of non-AGN galaxies. Visual signs of disturbances are found in about 25 per cent of sources in both the AGN hosts and control galaxies. Using both visual classification and quantitative morphology measures, we show that the levels of disturbance are not enhanced when compared to a matched control sample. We find no signs that major mergers play a dominant role in triggering AGN at high luminosities, suggesting that minor mergers and secular processes dominate AGN triggering up to the highest AGN luminosities. The upper limit on the enhanced fraction of major mergers is ≤20 per cent. While major mergers might increase the incidence of luminous AGN, they are not the prevalent triggering mechanism in the population of unobscured AGN.

  7. The Physical Constraints on a New LoBAL QSO at z = 4.82

    NASA Astrophysics Data System (ADS)

    Yi, Weimin; Green, Richard; Bai, Jin-Ming; Wang, Tinggui; Grier, Catherine J.; Trump, Jonathan R.; Brandt, William N.; Zuo, Wenwen; Yang, Jinyi; Wang, Feige; Yang, Chenwei; Wu, Xue-Bing; Zhou, Hongyan; Fan, Xiaohui; Jiang, Linhua; Yang, Qian; Varricatt, Watson; Kerr, Tom; Milne, Peter; Benigni, Sam; Wang, Jian-Guo; Zhang, Jujia; Wang, Fang; Wang, Chuan-Jun; Xin, Yu-Xin; Fan, Yu-Feng; Chang, Liang; Zhang, Xiliang; Lun, Bao-Li

    2017-04-01

    Very few low-ionization broad absorption line (LoBAL) QSOs have been found at high redshifts, to date. One high-redshift LoBAL QSO, J0122+1216, was recently discovered by the Lijiang 2.4 m Telescope, with an initial redshift determination of 4.76. Aiming to investigate its physical properties, we carried out follow-up observations in the optical and near-IR spectroscopy. Near-IR spectra from UKIRT and P200 confirm that it is a LoBAL, with a new redshift determination of 4.82 ± 0.01 based on the Mg ii emission-line. The new Mg ii redshift determination reveals strong blueshifts and asymmetry of the high-ionization emission lines. We estimate a black hole mass of ∼2.3 × 109 M ⊙ and Eddington ratio of ∼1.0 according to the empirical Mg ii-based single-epoch relation and bolometric correction factor. It is possible that strong outflows are the result of an extreme quasar environment driven by the high Eddington ratio. A lower limit on the outflowing kinetic power (>0.9% L Edd) is derived from both emission and absorption lines, indicating that these outflows play a significant role in the feedback process that regulates the growth of its black hole, as well as host galaxy evolution.

  8. The host galaxies and narrow-line regions of four double-peaked [OIII] AGNs

    SciTech Connect

    Villforth, Carolin; Hamann, Fred

    2015-03-01

    Major gas-rich mergers of galaxies are expected to play an important role in triggering and fueling luminous active galactic nuclei (AGNs). The mechanism of AGN fueling during mergers, however, remains poorly understood. We present deep multi-band (u/r/z) imaging and long-slit spectroscopy of four double-peaked [OIII] emitting AGNs. This class of object is likely associated with either kiloparsec-separated binary AGNs or final stage major mergers, although AGNs with complex narrow-line regions (NLRs) are known contaminants. Such objects are of interest since they represent the onset of AGN activity during the merger process. Three of the four double-peaked [OIII] emitters studied have been confirmed as major mergers using near-infrared imaging and one is a confirmed X-ray binary AGN. All AGNs are luminous, radio-quiet to radio-intermediate, and have redshifts of 0.1host morphologies and tidal features, while the remaining source is morphologically undisturbed down to low surface brightness limits (∼27 mag arcsec{sup −2} in r). The lack of morphological disturbances in this galaxy despite the fact that it is a close binary AGN suggests that the merger of a binary black hole can take longer than 1 Gyr. All AGNs hosted by merging galaxies have companions at distances ⩽150 kpc. The NLRs have large sizes (10 kpc < r < 100 kpc) and consist of compact clumps with considerable relative velocities between components (∼200–650 km s{sup −1}). We detect broad, predominantly blue, wings with velocities up to ∼1500 km s{sup −1} in [OIII], indicative of powerful outflows. The outflows are compact (<5 kpc) and co-spatial with nuclear regions showing considerable reddening, consistent with enhanced star formation. One source shows an offset between gas and stellar kinematics, consistent with either a bipolar flow or a counter-rotating gas disk. In all other sources, the ionized gas

  9. Narrow-band forbidden O III imaging of the QSO 4C 18.68 - A tidal tail revealed?

    NASA Technical Reports Server (NTRS)

    Shara, M. M.; Moffat, A. F. J.; Albrecht, R.

    1985-01-01

    The z = 0.313 quasar 4C 18.68 and its surroundings in the light of redshifted forbidden O III were imaged. The QSO appears much more extended than in broad-band images, with a large halo and possibly a faint tidal tail discerned. A broad-band I CCD image taken in 1 - 1.2 arcsec seeing resolves the QSO from a companion galaxy 3.6 arcsec distant, similar to many others seen in the field. It is suggested that the elongated and asymmetric shapes of some QSOs may be due to not-quite-resolved companion galaxies, and that caution be exercised in interpreting luminosity and color profiles as evidence for underlying spiral or elliptical structure.

  10. A nearby GRB host galaxy: VLT/X-shooter observations of HG 031203

    NASA Astrophysics Data System (ADS)

    Guseva, N. G.; Izotov, Y. I.; Fricke, K. J.; Henkel, C.

    2011-10-01

    Context. Long-duration gamma-ray bursts (LGRBs), which release enormous amounts of energy into the interstellar medium, occur in galaxies of generally low metallicity. For a better understanding of this phenomenon, detailed observations of the specific properties of the host galaxies (HG) and the environment near the LGRBs are mandatory. Aims: We aim at a spectroscopic analysis of HG 031203, the host galaxy of a LRGB burst, to obtain its properties. Our results will be compared with those of previous studies and the properties of a sample of luminous compact emission-line galaxies (LCGs) selected from SDSS DR7. Methods: Based on VLT/X-shooter spectroscopic observations taken from commissioning mode in the wavelength range ~λλ3200-24 000 Å, we use standard direct methods to evaluate physical conditions and element abundances. The resolving power of the instrument also allowed us to trace the kinematics of the ionised gas. Furthermore, we use X-shooter data together with Spitzer observations in the mid-infrared range for testing hidden star formation. Results: We derive an interstellar oxygen abundance of 12 + log O/H = 8.20 ± 0.03 for HG 031203. The observed fluxes of hydrogen lines correspond to the theoretical recombination values after correction for extinction with a single value C(Hβ) = 1.67. We produce the CLOUDY photoionisation H ii region model that reproduces observed emission-line fluxes of different ions in the optical range. This model also predicts emission-line fluxes in the near-infrared (NIR) and mid-infrared (MIR) ranges that agree well with the observed ones. This implies that the star-forming region observed in the optical range is the only source of ionisation and there is no additional source of ionisation seen in the NIR and MIR ranges that is hidden in the optical range. We find the composite kinematic structure from profiles of the strong emission lines by decomposing them into two Gaussian narrow and broad components. These components

  11. A glimpse at quasar host galaxy far-UV emission using damped Lyα's as natural coronagraphs

    SciTech Connect

    Cai, Zheng; Fan, Xiaohui; Wang, Ran; McGreer, Ian; Noterdaeme, Pasquier; Finley, Hayley; Petitjean, Patrick; Carithers, Bill; Bian, Fuyan; Miralda-Escudé, Jordi; Pâris, Isabelle; Schneider, Donald P.; Zakamska, Nadia L.; Ge, Jian; Slosar, Anze

    2014-10-01

    In merger-driven models of massive galaxy evolution, the luminous quasar phase is expected to be accompanied by vigorous star formation in quasar host galaxies. In this paper, we use high column density damped Lyα (DLA) systems along quasar sight lines as natural coronagraphs to directly study the far-UV (FUV) radiation from the host galaxies of luminous background quasars. We have stacked the spectra of ∼2000 DLA systems (N {sub H} {sub I} > 10{sup 20.6} cm{sup –2}) with a median absorption redshift (z) = 2.6 selected from quasars observed in the SDSS-III Baryon Oscillation Spectroscopic Survey. We detect residual flux in the dark troughs of the composite DLA spectra. The level of this residual flux significantly exceeds systematic errors in the Sloan Digital Sky Survey fiber sky subtraction; furthermore, the residual flux is strongly correlated with the continuum luminosity of the background quasar, while uncorrelated with DLA column density or metallicity. We conclude that the flux could be associated with the average FUV radiation from the background quasar host galaxies (with medium redshift (z) = 3.1) that is not blocked by the intervening DLA. Assuming that all of the detected flux originates from quasar hosts, for the highest quasar luminosity bin ((L) = 2.5 × 10{sup 13} L {sub ☉}), the host galaxy has an FUV intensity of 1.5 ± 0.2 × 10{sup 40} erg s{sup –1} Å{sup –1}; this corresponds to an unobscured UV star formation rate of 9 M {sub ☉} yr{sup –1}.

  12. A Glimpse at Quasar Host Galaxy Far-UV Emission, Using Damped Lyα's as Natural Coronagraphs

    DOE PAGES

    Cai, Zheng; Fan, Xiaohui; Noterdaeme, Pasquier; ...

    2014-09-16

    In merger-driven models of massive galaxy evolution, the luminous quasar phase is expected to be accompanied by vigorous star formation in quasar host galaxies. In this paper, we use high column density damped Lyα (DLA) systems along quasar sight lines as natural coronagraphs to directly study the far-UV (FUV) radiation from the host galaxies of luminous background quasars. Here, we have stacked the spectra of ~2000 DLA systems (NHI > 1020.6cm–2) with a median absorption redshiftmore » $$\\langle$$z$$\\rangle$$ = 2.6 selected from quasars observed in the SDSS-III Baryon Oscillation Spectroscopic Survey. We detect residual flux in the dark troughs of the composite DLA spectra. The level of this residual flux significantly exceeds systematic errors in the Sloan Digital Sky Survey fiber sky subtraction; furthermore, the residual flux is strongly correlated with the continuum luminosity of the background quasar, while uncorrelated with DLA column density or metallicity. We conclude that the flux could be associated with the average FUV radiation from the background quasar host galaxies (with medium redshift $$\\langle$$z$$\\rangle$$ = 3.1) that is not blocked by the intervening DLA. Finally, assuming that all of the detected flux originates from quasar hosts, for the highest quasar luminosity bin ($$\\langle$$L$$\\rangle$$ = 2.5 × 1013 L⊙), the host galaxy has an FUV intensity of 1.5 ± 0.2 × 1040 erg s–1 Å–1; this corresponds to an unobscured UV star formation rate of 9 M⊙ yr–1.« less

  13. A Glimpse at Quasar Host Galaxy Far-UV Emission, Using Damped Lyα's as Natural Coronagraphs

    SciTech Connect

    Cai, Zheng; Fan, Xiaohui; Noterdaeme, Pasquier; Wang, Ran; McGreer, Ian; Carithers, Bill; Bian, Fuyan; Miralda-Escudé, Jordi; Finley, Hayley; Pâris, Isabelle; Schneider, Donald P.; Zakamska, Nadia L.; Ge, Jian; Petitjean, Patrick; Slosar, Anze

    2014-09-16

    In merger-driven models of massive galaxy evolution, the luminous quasar phase is expected to be accompanied by vigorous star formation in quasar host galaxies. In this paper, we use high column density damped Lyα (DLA) systems along quasar sight lines as natural coronagraphs to directly study the far-UV (FUV) radiation from the host galaxies of luminous background quasars. Here, we have stacked the spectra of ~2000 DLA systems (NHI > 1020.6cm–2) with a median absorption redshift $\\langle$z$\\rangle$ = 2.6 selected from quasars observed in the SDSS-III Baryon Oscillation Spectroscopic Survey. We detect residual flux in the dark troughs of the composite DLA spectra. The level of this residual flux significantly exceeds systematic errors in the Sloan Digital Sky Survey fiber sky subtraction; furthermore, the residual flux is strongly correlated with the continuum luminosity of the background quasar, while uncorrelated with DLA column density or metallicity. We conclude that the flux could be associated with the average FUV radiation from the background quasar host galaxies (with medium redshift $\\langle$z$\\rangle$ = 3.1) that is not blocked by the intervening DLA. Finally, assuming that all of the detected flux originates from quasar hosts, for the highest quasar luminosity bin ($\\langle$L$\\rangle$ = 2.5 × 1013 L), the host galaxy has an FUV intensity of 1.5 ± 0.2 × 1040 erg s–1 Å–1; this corresponds to an unobscured UV star formation rate of 9 M yr–1.

  14. A Deep Survey of Low-Redshift Absorbers and Their Connections with Galaxies: Probing the Roles of Dwarfs, Satellites, and Large-Scale Environment

    NASA Astrophysics Data System (ADS)

    Burchett, Joseph

    2014-10-01

    In the not-too-distant past, the study of galaxy evolution neglected the vast interface between the stars in a galaxy and intergalactic space except for the dynamical effects of dark matter. Thanks to QSO absorption line spectroscopy and the Cosmic Origins Spectrograph {COS}, the circumgalactic medium {CGM} has come into sharp focus as a rich ecosystem playing a vital role in the evolution of the host galaxy. However, attributing the gas detected in absorption with host dwarf galaxies detected in optical surveys around the sightline becomes very difficult very quickly with increasing redshift. In addition, both targeted UV spectroscopy and ground-based galaxy surveys are resource intensive, which complicates compiling large, statistically robust samples of very-low-redshift absorber/galaxy pairs. We propose a CGM study of unprecedented statistical power by exploiting the vast number of sightlines in the HST/COS archive located within the Sloan Digital Sky Survey {SDSS} footprint to compile an estimated sample of 586 absorbers at z<0.015. This very-low-redshift criterion enables spectroscopic completeness down to L<0.01 L* galaxies in publicly available optical imaging and spectroscopy.Our survey is uniquely poised to address the following questions: {1} What is the role of dwarf galaxies that would be undetectable at higher redshift in giving rise to the gas detected in QSO spectroscopy? {2} How does galaxy environment and large-scale structure affect the CGM and what are the implications for environmental quenching of star formation? {3} How efficiently do feedback mechanisms expel metal-enriched gas to great distances into the galaxy halo and into the IGM?

  15. GEMINI SPECTROSCOPY OF THE SHORT-HARD GAMMA-RAY BURST GRB 130603B AFTERGLOW AND HOST GALAXY

    SciTech Connect

    Cucchiara, A.; Prochaska, J. X.; Werk, J.; Cenko, S. B.; Cardwell, A.; Turner, J.; Bloom, J. S.; Cobb, B. E.

    2013-11-10

    We present early optical photometry and spectroscopy of the afterglow and host galaxy of the bright short-duration gamma-ray burst GRB 130603B discovered by the Swift satellite. Using our Target of Opportunity program on the Gemini South telescope, our prompt optical spectra reveal a strong trace from the afterglow superimposed on continuum and emission lines from the z = 0.3568 ± 0.0005 host galaxy. The combination of a relatively bright optical afterglow (r' = 21.52 at Δt = 8.4 hr), together with an observed offset of 0.''9 from the host nucleus (4.8 kpc projected distance at z = 0.3568), allow us to extract a relatively clean spectrum dominated by afterglow light. Furthermore, the spatially resolved spectrum allows us to constrain the properties of the explosion site directly, and compare these with the host galaxy nucleus, as well as other short-duration GRB host galaxies. We find that while the host is a relatively luminous (L∼0.8 L{sup *}{sub B}), star-forming (SFR = 1.84 M{sub ☉} yr{sup –1}) galaxy with almost solar metallicity, the spectrum of the afterglow exhibits weak Ca II absorption features but negligible emission features. The explosion site therefore lacks evidence of recent star formation, consistent with the relatively long delay time distribution expected in a compact binary merger scenario. The star formation rate (SFR; both in an absolute sense and normalized to the luminosity) and metallicity of the host are both consistent with the known sample of short-duration GRB hosts and with recent results which suggest GRB 130603B emission to be the product of the decay of radioactive species produced during the merging process of a neutron-star-neutron-star binary ({sup k}ilonova{sup )}. Ultimately, the discovery of more events similar to GRB 130603B and their rapid follow-up from 8 m class telescopes will open new opportunities for our understanding of the final stages of compact-objects binary systems and provide crucial information

  16. Gamma-ray burst afterglows as probes of their host galaxies and the cosmos

    NASA Astrophysics Data System (ADS)

    Cucchiara, Antonino

    2010-12-01

    Gamma-ray Bursts (GRBs) represent the sole class of catastrophic phenomena seen over almost the entire history of the Universe. Their extreme luminosities in high energy gamma-ray radiation make them readily detectable, even with relatively small satellite-based detectors, out to the earliest cosmic epochs. Moreover, the brilliance of their fading afterglow light, routinely observed in X-ray, optical, near-infrared, and radio wavelengths, allows them to be exploited -- for hours, days, or weeks -- as cosmic lighthouses, probing the conditions of gas and dust along the line of sight, through their host galaxies and the cosmos at large. Since the November 2004 launch of Swift, this GRB-focused NASA mission has discovered more than 500 GRBs, in almost all cases reporting the burst coordinates to ground-based observers within seconds of the event. The availability of prompt burst positions from Swift, combined with promptly-reported flux measurements from instruments on Swift and an array of ground-based robotic telescopes, have enabled targeted spectroscopic campaigns that have gathered detailed observations of the young, bright afterglows of hundreds of these events. This thesis reports the results of my own efforts over the past 5 years, analyzing imaging and spectroscopic observations of Swift-detected GRBs as triggered according to my own requests, or as gathered from public data archives. In Chapter 2, I discuss our follow-up campaign for GRB090429B, one of our best "extreme redshift" (z > 8) candidates. This burst followed closely on the spectroscopicallyconfirmed z = 8.2 GRB090423, and our multiwavelength observations and SED modeling demonstrate the value and limitation of such studies, in cases where a spectroscopic redshift cannot be gathered in a timely fashion. I also address the importance of such extreme-redshift events from a cosmological perspective. In Chapter 3, I use high-resolution GRB afterglow spectra to study the properties of intervening

  17. ON THE VARIATIONS OF FUNDAMENTAL CONSTANTS AND ACTIVE GALACTIC NUCLEUS FEEDBACK IN THE QUASI-STELLAR OBJECT HOST GALAXY RXJ0911.4+0551 at z = 2.79

    SciTech Connect

    Weiss, A.; Henkel, C.; Menten, K. M.; Walter, F.; Downes, D.; Cox, P.; Carrili, C. L.

    2012-07-10

    We report on sensitive observations of the CO(J = 7{yields}6) and C I({sup 3}P{sub 2} {yields} {sup 3}P{sub 1}) transitions in the z = 2.79 QSO host galaxy RXJ0911.4+0551 using the IRAM Plateau de Bure interferometer. Our extremely high signal-to-noise spectra combined with the narrow CO line width of this source (FWHM = 120 km s{sup -1}) allows us to estimate sensitive limits on the spacetime variations of the fundamental constants using two emission lines. Our observations show that the C I and CO line shapes are in good agreement with each other but that the C I line profile is of the order of 10% narrower, presumably due to the lower opacity in the latter line. Both lines show faint wings with velocities up to {+-}250 km s{sup -1}, indicative of a molecular outflow. As such, the data provide direct evidence for negative feedback in the molecular gas phase at high redshift. Our observations allow us to determine the observed frequencies of both transitions with so far unmatched accuracy at high redshift. The redshift difference between the CO and C I lines is sensitive to variations of {Delta}F/F with F = {alpha}{sup 2}/{mu} where {alpha} is the fine structure constant and {mu} is the electron-to-proton mass ratio. We find {Delta}F/F (6.9 {+-} 3.7) Multiplication-Sign 10{sup -6} at a look-back time of 11.3 Gyr, which, within the uncertainties, is consistent with no variations of the fundamental constants.

  18. A NEARBY GAMMA-RAY BURST HOST PROTOTYPE FOR z {approx} 7 LYMAN-BREAK GALAXIES: SPITZER-IRS AND X-SHOOTER SPECTROSCOPY OF THE HOST GALAXY OF GRB 031203

    SciTech Connect

    Watson, D.; French, J.; Hjorth, J.; Malesani, D.; Fynbo, J. P. U.; Castro Ceron, J. M.; Christensen, L.; O'Halloran, B.; Michalowski, M.; Gordon, K. D.; Covino, S.

    2011-11-01

    Gamma-ray burst (GRB) host galaxies have been studied extensively in optical photometry and spectroscopy. Here we present the first mid-infrared spectrum of a GRB host, HG 031203. It is one of the nearest GRB hosts at z = 0.1055, allowing both low- and high-resolution spectroscopy with the Spitzer Infrared Spectrograph (IRS). Medium-resolution UV to K-band spectroscopy with the X-shooter spectrograph on the Very Large Telescope is also presented, along with Spitzer IRAC and MIPS photometry, as well as radio and submillimeter observations. These data allow us to construct a UV to radio spectral energy distribution with almost complete spectroscopic coverage from 0.3 to 35 {mu}m of a GRB host galaxy for the first time, potentially valuable as a template for future model comparisons. The IRS spectra show strong, high-ionization fine structure line emission indicative of a hard radiation field in the galaxy-in particular the [S IV]/[S III] and [Ne III]/[Ne II] ratios-suggestive of strong ongoing star formation and a very young stellar population. The absence of any polycyclic aromatic hydrocarbon emission supports these conclusions, as does the probable hot peak dust temperature, making HG 031203 similar to the prototypical blue compact dwarf galaxy (BCD), II Zw 40. The selection of HG 031203 via the presence of a GRB suggests that it might be a useful analog of very young star-forming galaxies in the early universe, and hints that local BCDs may be used as more reliable analogs of star formation in the early universe than typical local starbursts. We look at the current debate on the ages of the dominant stellar populations in z {approx} 7 and z {approx} 8 galaxies in this context. The nebular line emission is so strong in HG 031203 that at z {approx} 7, it can reproduce the spectral energy distributions of z-band dropout galaxies with elevated IRAC 3.6 and 4.5 {mu}m fluxes without the need to invoke a 4000 A break. Indeed, photometry of HG 031203 shows elevation of

  19. Host Galaxy Spectra of Stripped SN from the Palomar Transient Factory: SN Progenitor Diagnostics and the SN-GRB Connection

    NASA Astrophysics Data System (ADS)

    Modjaz, Maryam; Gal-Yam, Avishay; Arcavi, Iair

    2012-02-01

    Stripped core-collapse supernovae (Stripped SNe) are powerful cosmic engines that energize and enrich the ISM and that sometimes accompany GRBs, but the exact mass and metallicity range of their massive progenitors is not known, nor the detailed physics of the explosion. We propose to continue conducting the first uniform and statistically significant study of host galaxies of 60 stripped SNe from the same innovative, homogeneous and galaxy-unbiased survey Palomar Transient Factory in order to determine the environmental conditions that influence the various kinds of massive stellar deaths. By obtaining spectra of the immediate host environments of our sample of stripped SN, we will (1) measure local abundances in order to differentiate between the two progenitor scenarios for stripped SN and (2) derive stellar population ages, masses and star formation histories via detailed stellar population synthesis models. Moreover, we will test if natal chemical abundance has effects on basic SN characteristics, such as peak luminosity. Any observed trends will have ramifications on SN and GRB explosion models and imply important demographic SN considerations. Our dataset will provide a crucial complimentary set to host galaxy studies of long-duration GRBs and pave the way for host studies of transients and SN found via upcoming surveys such as LSST.

  20. THE HOST GALAXY OF THE SUPER-LUMINOUS SN 2010gx AND LIMITS ON EXPLOSIVE {sup 56}Ni PRODUCTION

    SciTech Connect

    Chen, Ting-Wan; Smartt, Stephen J.; Kotak, Rubina; McCrum, Matt; Fraser, Morgan; Bresolin, Fabio; Kudritzki, Rolf-Peter; Pastorello, Andrea; Valenti, Stefano

    2013-02-01

    Super-luminous supernovae have a tendency to occur in faint host galaxies which are likely to have low mass and low metallicity. While these extremely luminous explosions have been observed from z = 0.1 to 1.55, the closest explosions allow more detailed investigations of their host galaxies. We present a detailed analysis of the host galaxy of SN 2010gx (z = 0.23), one of the best studied super-luminous type Ic supernovae. The host is a dwarf galaxy (M{sub g} = -17.42 {+-} 0.17) with a high specific star formation rate. It has a remarkably low metallicity of 12 + log (O/H) = 7.5 {+-} 0.1 dex as determined from the detection of the [O III] {lambda}4363 line. This is the first reliable metallicity determination of a super-luminous stripped-envelope supernova host. We collected deep multi-epoch imaging with Gemini + GMOS between 240 and 560 days after explosion to search for any sign of radioactive {sup 56}Ni, which might provide further insights on the explosion mechanism and the progenitor's nature. We reach griz magnitudes of m{sub AB} {approx} 26, but do not detect SN 2010gx at these epochs. The limit implies that any {sup 56}Ni production was similar to or below that of SN 1998bw (a luminous type Ic SN that produced around 0.4 M{sub Sun} of {sup 56}Ni). The low volumetric rates of these supernovae ({approx}10{sup -4} of the core-collapse population) could be qualitatively matched if the explosion mechanism requires a combination of low-metallicity (below 0.2 Z{sub Sun }), high progenitor mass (>60 M{sub Sun }) and high rotation rate (fastest 10% of rotators).

  1. The Molecular Gas Content of z < 0.1 Radio Galaxies: Linking the Active Galactic Nucleus Accretion Mode to Host Galaxy Properties

    NASA Astrophysics Data System (ADS)

    Smolčić, V.; Riechers, D. A.

    2011-04-01

    One of the main achievements in modern cosmology is the so-called unified model, which successfully describes most classes of active galactic nuclei (AGNs) within a single physical scheme. However, there is a particular class of radio-luminous AGNs that presently cannot be explained within this framework—the "low-excitation" radio AGN (LERAGN). Recently, a scenario has been put forward which predicts that LERAGNs and their regular "high-excitation" radio AGN (HERAGN) counterparts represent different (red sequence versus green valley) phases of galaxy evolution. These different evolutionary states are also expected to be reflected in their host galaxy properties, in particular their cold gas content. To test this, here we present CO(1→0) observations toward a sample of 11 of these systems conducted with CARMA. Combining our observations with literature data, we derive molecular gas masses (or upper limits) for a complete, representative, sample of 21 z < 0.1 radio AGNs. Our results yield that HERAGNs on average have a factor of ~7 higher gas masses than LERAGNs. We also infer younger stellar ages, lower stellar, halo, and central supermassive black masses, as well as higher black hole accretion efficiencies in HERAGNs relative to LERAGNs. These findings support the idea that HERAGNs and LERAGNs form two physically distinct populations of galaxies that reflect different stages of massive galaxy buildup.

  2. Probing the complex environments of GRB host galaxies and intervening systems: high resolution spectroscopy of GRB050922C

    NASA Astrophysics Data System (ADS)

    Piranomonte, S.; Vergani, S.; Fiore, F.; D'Elia, V.; Krongold, Y.; Nicastro, F.; Stella, L.

    2009-05-01

    We use high resolution spectroscopic observations of the afterglow of GRB050922C, in order to investigate the environment of gamma ray bursts (GRBs) and the interstellar matter of their host galaxies. We found that, as for most high resolution spectra of GRBs, the spectrum of the afterglow of GRB050922C is complex. The detection of lines of neutral elements like MgI and the detection of fine-structure levels of the ions FeII, SiII and CII allows us to separate components in the GRB ISM along the line of sight. GRB afterglow spectra can be used to disentangle the contribution of the different parts of the GRB host galaxy and to study their properties.

  3. The effects of host galaxy properties on merging compact binaries detectable by LIGO

    NASA Astrophysics Data System (ADS)

    O'Shaughnessy, R.; Bellovary, J. M.; Brooks, A.; Shen, S.; Governato, F.; Christensen, C. R.

    2017-01-01

    Cosmological simulations of galaxy formation can produce present-day galaxies with a large range of assembly and star formation histories. A detailed study of the metallicity evolution and star formation history of such simulations can assist in predicting Laser Interferometer Gravitational-Wave Observatory (LIGO)-detectable compact object binary mergers. Recent simulations of compact binary evolution suggest that the compact object merger rate depends sensitively on the progenitor's metallicity. Rare low-metallicity star formation during galaxy assembly can produce more detected compact binaries than typical star formation. Using detailed simulations of galaxy and chemical evolution, we determine how sensitively the compact binary populations of galaxies with a similar present-day appearance depend on the details of their assembly. We also demonstrate by concrete example the extent to which dwarf galaxies overabundantly produce compact binary mergers, particularly binary black holes, relative to more massive galaxies. We discuss the implications for transient multimessenger astronomy with compact binary sources.

  4. Detection of emission lines from z ˜ 3 DLAs towards the QSO J2358+0149

    NASA Astrophysics Data System (ADS)

    Srianand, Raghunathan; Hussain, Tanvir; Noterdaeme, Pasquier; Petitjean, Patrick; Krühler, Thomas; Japelj, Jure; Pâris, Isabelle; Kashikawa, Nobunari

    2016-07-01

    Using VLT/X-shooter, we searched for emission line galaxies associated with four damped Lyman α systems (DLAs) and one sub-DLA at 2.73 ≤z ≤3.25 towards QSO J2358+0149. We detect [O III] emission from a `low-cool' DLA at zabs = 2.9791 (having log N(H I) = 21.69 ± 0.10, [Zn/H] = -1.83 ± 0.18) at an impact parameter of, ρ ˜ 12 kpc. The associated galaxy is compact with a dynamical mass of (1-6) × 109 M⊙, very high excitation ([O III]/[O II] and [O III]/[Hβ] both greater than 10), 12+[O/H]≤8.5 and moderate star formation rate (SFR ≤2 M⊙ yr-1). Such properties are typically seen in the low-z extreme blue compact dwarf galaxies. The kinematics of the gas is inconsistent with that of an extended disc and the gas is part of either a large scale wind or cold accretion. We detect Lyα emission from the zabs = 3.2477 DLA [having log N(H I) = 21.12 ± 0.10 and [Zn/H] = -0.97 ± 0.13]. The Lyα emission is redshifted with respect to the metal absorption lines by 320 km s-1, consistent with the location of the red hump expected in radiative transport models. We derive SFR ˜0.2-1.7 M⊙ yr-1 and Lyα escape fraction of ≥10 per cent. No other emission line is detected from this system. Because the DLA has a small velocity separation from the quasar (˜500 km s-1) and the DLA emission is located within a small projected distance (ρ < 5 kpc), we also explore the possibility that the Lyα emission is being induced by the QSO itself. QSO-induced Lyα fluorescence is possible if the DLA is within a physical separation of 340 kpc to the QSO. Detection of stellar continuum light and/or the oxygen emission lines would disfavour this possibility. We do not detect any emission line from the remaining three systems.

  5. A Nearby Gamma-Ray Burst Host Prototype for z ~ 7 Lyman-break Galaxies: Spitzer-IRS and X-shooter Spectroscopy of the Host Galaxy of GRB 031203

    NASA Astrophysics Data System (ADS)

    Watson, D.; French, J.; Christensen, L.; O'Halloran, B.; Michałowski, M.; Hjorth, J.; Malesani, D.; Fynbo, J. P. U.; Gordon, K. D.; Castro Cerón, J. M.; Covino, S.; Reinfrank, R. F.

    2011-11-01

    Gamma-ray burst (GRB) host galaxies have been studied extensively in optical photometry and spectroscopy. Here we present the first mid-infrared spectrum of a GRB host, HG 031203. It is one of the nearest GRB hosts at z = 0.1055, allowing both low- and high-resolution spectroscopy with the Spitzer Infrared Spectrograph (IRS). Medium-resolution UV to K-band spectroscopy with the X-shooter spectrograph on the Very Large Telescope is also presented, along with Spitzer IRAC and MIPS photometry, as well as radio and submillimeter observations. These data allow us to construct a UV to radio spectral energy distribution with almost complete spectroscopic coverage from 0.3 to 35 μm of a GRB host galaxy for the first time, potentially valuable as a template for future model comparisons. The IRS spectra show strong, high-ionization fine structure line emission indicative of a hard radiation field in the galaxy—in particular the [S IV]/[S III] and [Ne III]/[Ne II] ratios—suggestive of strong ongoing star formation and a very young stellar population. The absence of any polycyclic aromatic hydrocarbon emission supports these conclusions, as does the probable hot peak dust temperature, making HG 031203 similar to the prototypical blue compact dwarf galaxy (BCD), II Zw 40. The selection of HG 031203 via the presence of a GRB suggests that it might be a useful analog of very young star-forming galaxies in the early universe, and hints that local BCDs may be used as more reliable analogs of star formation in the early universe than typical local starbursts. We look at the current debate on the ages of the dominant stellar populations in z ~ 7 and z ~ 8 galaxies in this context. The nebular line emission is so strong in HG 031203 that at z ~ 7, it can reproduce the spectral energy distributions of z-band dropout galaxies with elevated IRAC 3.6 and 4.5 μm fluxes without the need to invoke a 4000 Å break. Indeed, photometry of HG 031203 shows elevation of the broadband V

  6. XMM-Newton reveals a Seyfert-like X-ray spectrum in the z = 3.6 QSO B1422+231

    NASA Astrophysics Data System (ADS)

    Dadina, M.; Vignali, C.; Cappi, M.; Lanzuisi, G.; Ponti, G.; De Marco, B.; Chartas, G.; Giustini, M.

    2016-08-01

    Context. Matter flows from the central regions of quasi-stellar objects (QSOs) during their active phases are probably responsible for the properties of the super-massive black holes and those of the bulges of host galaxies. To understand how this mechanism works, we need to characterize the geometry and the physical state of the accreting matter at cosmological redshifts, when QSO activity is at its peak. Aims: We aim to use X-ray data to probe the matter inflow at the very center of a QSO at z = 3.62. While complex absorption, the iron K emission line, reflection hump, and high-energy cutoff are known to be almost ubiquitous in nearby active galactic nuclei (AGN), only a few distant objects are known to exhibit some of them. Methods: The few high-quality spectra of distant QSO were collected by adding sparse pointings of single objects obtained during X-ray monitoring campaigns. This could have introduced spurious spectral features due to source variability and/or microlensing. To avoid such problems, we decided to collect a single-epoch and high-quality X-ray spectrum of a distant AGN. We thus picked up the z = 3.62 QSO B1422+231, whose flux, enhanced by gravitationally lensing, is proven to be among the brightest lensed QSOs in X-rays (F2-10 keV ~ 10-12 erg s-1 cm-2). Results: The X-ray spectrum of B1422+231 is found to be very similar to the one of a typical nearby Seyfert galaxy. Neutral absorption is clearly detected (NH ~ 5 × 1021 cm-2 at the redshift of the source), while a strong absorption edge is measured at E ~ 7.5 keV with an optical depth of τ ~ 0.14. We also find hints of the FeKα line in emission at E ~ 6.4 keV line (EW ≲ 70 eV), and a hump is detected in the E ~ 15 - 20 keV energy band (rest frame) in excess of what is predicted by a simple absorbed power-law. Conclusions: The spectrum can best be modeled with two rather complex models; one assumes ionized and partially covering matter along the line of sight, the other is characterized by a

  7. A population of massive, luminous galaxies hosting heavily dust-obscured gamma-ray bursts: Implications for the use of GRBs as tracers of cosmic star formation

    SciTech Connect

    Perley, D. A.; Levan, A. J.; Tanvir, N. R.; Cenko, S. B.; Bloom, J. S.; Filippenko, A. V.; Morgan, A. N.; Hjorth, J.; Krühler, T.; Fynbo, J. P. U.; Milvang-Jensen, B.; Fruchter, A.; Kalirai, J.; Jakobsson, P.; Prochaska, J. X.

    2013-12-01

    We present observations and analysis of the host galaxies of 23 heavily dust-obscured gamma-ray bursts (GRBs) observed by the Swift satellite during the years 2005-2009, representing all GRBs with an unambiguous host-frame extinction of A{sub V} > 1 mag from this period. Deep observations with Keck, Gemini, Very Large Telescope, Hubble Space Telescope, and Spitzer successfully detect the host galaxies and establish spectroscopic or photometric redshifts for all 23 events, enabling us to provide measurements of the intrinsic host star formation rates, stellar masses, and mean extinctions. Compared to the hosts of unobscured GRBs at similar redshifts, we find that the hosts of dust-obscured GRBs are (on average) more massive by about an order of magnitude and also more rapidly star forming and dust obscured. While this demonstrates that GRBs populate all types of star-forming galaxies, including the most massive, luminous systems at z ≈ 2, at redshifts below 1.5 the overall GRB population continues to show a highly significant aversion to massive galaxies and a preference for low-mass systems relative to what would be expected given a purely star-formation-rate-selected galaxy sample. This supports the notion that the GRB rate is strongly dependent on metallicity, and may suggest that the most massive galaxies in the universe underwent a transition in their chemical properties ∼9 Gyr ago. We also conclude that, based on the absence of unobscured GRBs in massive galaxies and the absence of obscured GRBs in low-mass galaxies, the dust distributions of the lowest-mass and the highest-mass galaxies are relatively homogeneous, while intermediate-mass galaxies (∼10{sup 9} M {sub ☉}) have diverse internal properties.

  8. The Afterglow and Early-type Host Galaxy of the Short GRB 150101B at z = 0.1343

    NASA Astrophysics Data System (ADS)

    Fong, W.; Margutti, R.; Chornock, R.; Berger, E.; Shappee, B. J.; Levan, A. J.; Tanvir, N. R.; Smith, N.; Milne, P. A.; Laskar, T.; Fox, D. B.; Lunnan, R.; Blanchard, P. K.; Hjorth, J.; Wiersema, K.; van der Horst, A. J.; Zaritsky, D.

    2016-12-01

    We present the discovery of the X-ray and optical afterglows of the short-duration GRB 150101B, pinpointing the event to an early-type host galaxy at z = 0.1343 ± 0.0030. This makes GRB 150101B the most nearby short gamma-ray burst (GRB) with an early-type host galaxy discovered to date. Fitting the spectral energy distribution of the host galaxy results in an inferred stellar mass of ≈ 7× {10}10 {M}⊙ , stellar population age of ≈2-2.5 Gyr, and star formation rate of ≲0.4 M ⊙ yr-1. The host of GRB 150101B is one of the largest and most luminous short GRB host galaxies, with a B-band luminosity of ≈ 4.3{L}* and half-light radius of ≈8 kpc. GRB 150101B is located at a projected distance of 7.35 ± 0.07 kpc from its host center and lies on a faint region of its host rest-frame optical light. Its location, combined with the lack of associated supernova, is consistent with an NS-NS/NS-BH merger progenitor. From modeling the evolution of the broadband afterglow, we calculate isotropic-equivalent gamma-ray and kinetic energies of ≈ 1.3× {10}49 erg and ≈ (6{--}14)× {10}51 erg, respectively, a circumburst density of ≈ (0.8{--}4)× {10}-5 cm-3, and a jet opening angle of ≳9°. Using observations extending to ≈30 days, we place upper limits of ≲ (2{--}4)× {10}41 erg s-1 on associated kilonova emission. We compare searches following previous short GRBs to existing kilonova models and demonstrate the difficulty of performing effective kilonova searches from cosmological short GRBs using current ground-based facilities. We show that at the Advanced LIGO/VIRGO horizon distance of 200 Mpc, searches reaching depths of ≈23-24 AB mag are necessary to probe a meaningful range of kilonova models.

  9. Current QSO statistics - Implications for the intergalactic medium

    NASA Technical Reports Server (NTRS)

    Sherman, R. D.

    1981-01-01

    The results of numerous QSO surveys have been compiled and analyzed to form a single spatially averaged QSO ionizing function that is independent of evolution mode (number density or luminosity). An intergalactic medium (IGM) that satisfies the observational constraints may now have a density with respect to closure of approximately 0.1, which is substantially less than hitherto modeled. The aggregate of QSO data also indicate that if evolution is due to number density, then, when split into luminosity classes, an exponential in look-back time fits the data better than a power law, and the evolution rates increase roughly with absolute luminosity if analyzed by the exponential.

  10. Cosmological test with the QSO Hubble diagram

    NASA Astrophysics Data System (ADS)

    López-Corredoira, M.; Melia, F.; Lusso, E.; Risaliti, G.

    2016-03-01

    A Hubble diagram (HD) has recently been constructed in the redshift range 0 ≲ z ≲ 6.5 using a nonlinear relation between the ultraviolet (UV) and X-ray luminosities of quasi stellar objects (QSOs). The Type Ia Supernovae (SN) HD has already provided a high-precision test of cosmological models, but the fact that the QSO distribution extends well beyond the supernova range (z ≲ 1.8), in principle provides us with an important complementary diagnostic whose significantly greater leverage in z can impose tighter constraints on the distance versus redshift relationship. In this paper, we therefore perform an independent test of nine different cosmological models, among which six are expanding, while three are static. Many of these are disfavored by other kinds of observations (including the aforementioned Type Ia SNe). We wish to examine whether the QSO HD confirms or rejects these earlier conclusions. We find that four of these models (Einstein-de Sitter, the Milne universe, the static universe with simple tired light and the static universe with plasma tired light) are excluded at the > 99% C.L. The quasi-steady state model is excluded at > 95% C.L. The remaining four models (ΛCDM/wCDM, the Rh = ct universe, the Friedmann open universe and a static universe with a linear Hubble law) all pass the test. However, only ΛCDM/wCDM and Rh = ct also pass the Alcock-Paczyński (AP) test. The optimized parameters in ΛCDM/wCDM are Ωm = 0.20-0.20+0.24 and wde = -1.2-∞+1.6 (the dark energy equation-of-state). Combined with the AP test, these values become Ωm = 0.38-0.19+0.20 and wde = -0.28-0.40+0.52. But whereas this optimization of parameters in ΛCDM/wCDM creates some tension with their concordance values, the Rh = ct universe has the advantage of fitting the QSO and AP data without any free parameters.

  11. Properties of compact HII regions and their host clumps in the inner vs outer Galaxy - early results from SASSy

    NASA Astrophysics Data System (ADS)

    Djordjevic, Julie; Thompson, Mark; Urquhart, James S.

    2017-01-01

    We present a catalog of compact and ultracompact HII regions for all Galactocentric radii. Previous catalogs focus on the inner Galaxy (Rgal ≤ 8 kpc) but the recent SASSy 870 µm survey allows us to identify regions out to ~20 kpc. Early samples are also filled with false classifications leading to uncertainty when deriving star formation efficiencies in Galactic models. These objects have similar mid-IR colours to HII regions. Urquhart et al. (2013) found that they could use mid-IR, submm, and radio data to identify the genuine compact HII regions, avoiding confusion. They used this method on a small portion of the Galaxy (10 < l < 60), identifying 213 HII regions embedded in 170 clumps. We use ATLASGAL and SASSy, crossmatched with RMS, to sample the remaining galactic longitudes out to Rgal = 20 kpc. We derive the properties of the identified compact HII regions and their host clumps while addressing the implications for recent massive star formation in the outer Galaxy. Observations towards nearby galaxies are biased towards massive stars, affecting simulations and overestimating models for galactic evolution and star formation rates. The Milky Way provides the ideal template for studying factors affecting massive star formation rates and efficiencies at high resolution, thus fine-tuning those models. We find that there is no significant change in the rate of massive star formation in the outer vs inner Galaxy. Despite some peaks in known complexes and possible correlation with spiral arms, the outer Galaxy appears to produce massive stars as efficiently as the inner regions. However, many of the potential star forming SASSy clumps have no available radio counterpart to confirm the presence of an HII region or other star formation tracer. Follow-up observations will be required to verify this conclusion and are currently in progress.

  12. Statistical and physical evolution of QSO's

    NASA Technical Reports Server (NTRS)

    Caditz, David; Petrosian, Vahe

    1989-01-01

    The relationship between the physical evolution of discrete extragalactic sources, the statistical evolution of the observed population of sources, and the cosmological model is discussed. Three simple forms of statistical evolution: pure luminosity evolution (PLE), pure density evolution (PDE), and generalized luminosity evolution (GLE), are considered in detail together with what these forms imply about the physical evolution of individual sources. Two methods are used to analyze the statistical evolution of the observed distribution of QSO's (quasars) from combined flux limited samples. It is shown that both PLE and PDE are inconsistent with the data over the redshift range 0 less than z less than 2.2, and that a more complicated form of evolution such as GLE is required, independent of the cosmological model. This result is important for physical models of AGN, and in particular, for the accretion disk model which recent results show may be inconsistent with PLE.

  13. Probing the complex environments of GRB host galaxies and intervening systems: high resolution spectroscopy of GRB050922C

    NASA Astrophysics Data System (ADS)

    Piranomonte, S.; Ward, P. A.; Fiore, F.; Vergani, S. D.; D'Elia, V.; Krongold, Y.; Nicastro, F.; Meurs, E. J. A.; Chincarini, G.; Covino, S.; Della Valle, M.; Fugazza, D.; Norci, L.; Sbordone, L.; Stella, L.; Tagliaferri, G.; Burrows, D. N.; Gehrels, N.; Goldoni, P.; Malesani, D.; Mirabel, I. F.; Pellizza, L. J.; Perna, R.

    2008-12-01

    Aims: The aim of this paper is to investigate the environment of gamma ray bursts (GRBs) and the interstellar matter of their host galaxies. Methods: To this purpose we use high resolution spectroscopic observations of the afterglow of GRB050922C, obtained with UVES/VLT ~ 3.5 h after the GRB event. Results: We found that, as for most high resolution spectra of GRBs, the spectrum of the afterglow of GRB050922C is complex. At least seven components contribute to the main absorption system at z=2.1992. The detection of lines of neutral elements like MgI and the detection of fine-structure levels of the ions FeII, SiII and CII allows us to separate components in the GRB ISM along the line of sight. Moreover, in addition to the main system, we analyzed the five intervening systems between z = 2.077 and z = 1.5664 identified along the GRB line of sight. Conclusions: GRB afterglow spectra are very complex, but full of information. This can be used to disentangle the contribution of the different parts of the GRB host galaxy and to study their properties. Our metallicity estimates agree with the scenario of GRBs exploding in low metallicity galaxies Based on observations collected at the European Southern Observatory (ESO) with the VLT/Kueyen telescope, Paranal, Chile, in the framework of program 075.A-0603.

  14. GRB 090417B AND ITS HOST GALAXY: A STEP TOWARD AN UNDERSTANDING OF OPTICALLY DARK GAMMA-RAY BURSTS

    SciTech Connect

    Holland, Stephen T.; Cummings, Jay R.; Fonseca, Emmanuel; Sbarufatti, Boris; Shen, Rongfeng; Schady, Patricia; Still, Martin; Fynbo, Johan P. U.; Jakobsson, Pall; Leitet, Elisabet; Linne, Staffan; Roming, Peter W. A.; Zhang Bing

    2010-07-01

    GRB 090417B was an unusually long burst with a T{sub 90} duration of at least 2130 s and a multi-peaked light curve at energies of 15-150 keV. It was optically dark and has been associated with a bright star-forming galaxy at a redshift of 0.345 that is broadly similar to the Milky Way. This is one of the few cases where a host galaxy has been clearly identified for a dark gamma-ray burst (GRB) and thus an ideal candidate for studying the origin of dark bursts. We find that the dark nature of GRB 090417B cannot be explained by high redshift, incomplete observations, or unusual physics in the production of the afterglow. Assuming the standard relativistic fireball model for the afterglow we find that the optical flux is at least 2.5 mag fainter than predicted by the X-ray flux. The Swift/XRT X-ray data are consistent with the afterglow being obscured by a dense, localized sheet of dust approximately 30-80 pc from the burst along the line of sight. Our results suggest that this dust sheet imparts an extinction of A{sub V} {approx_gt} 12 mag, which is sufficient to explain the missing optical flux. GRB 090417B is an example of a GRBs that is dark due to the localized dust structure in its host galaxy.

  15. The Swift GRB Host Galaxy Legacy Survey. II. Rest-frame Near-IR Luminosity Distribution and Evidence for a Near-solar Metallicity Threshold

    NASA Astrophysics Data System (ADS)

    Perley, D. A.; Tanvir, N. R.; Hjorth, J.; Laskar, T.; Berger, E.; Chary, R.; de Ugarte Postigo, A.; Fynbo, J. P. U.; Krühler, T.; Levan, A. J.; Michałowski, M. J.; Schulze, S.

    2016-01-01

    We present rest-frame near-IR (NIR) luminosities and stellar masses for a large and uniformly selected population of gamma-ray burst (GRB) host galaxies using deep Spitzer Space Telescope imaging of 119 targets from the Swift GRB Host Galaxy Legacy Survey spanning 0.03 < z < 6.3, and we determine the effects of galaxy evolution and chemical enrichment on the mass distribution of the GRB host population across cosmic history. We find a rapid increase in the characteristic NIR host luminosity between z ˜ 0.5 and z ˜ 1.5, but little variation between z ˜ 1.5 and z ˜ 5. Dust-obscured GRBs dominate the massive host population but are only rarely seen associated with low-mass hosts, indicating that massive star-forming galaxies are universally and (to some extent) homogeneously dusty at high redshift while low-mass star-forming galaxies retain little dust in their interstellar medium. Comparing our luminosity distributions with field surveys and measurements of the high-z mass-metallicity relation, our results have good consistency with a model in which the GRB rate per unit star formation is constant in galaxies with gas-phase metallicity below approximately the solar value but heavily suppressed in more metal-rich environments. This model also naturally explains the previously reported “excess” in the GRB rate beyond z ≳ 2 metals stifle GRB production in most galaxies at z < 1.5 but have only minor impact at higher redshifts. The metallicity threshold we infer is much higher than predicted by single-star models and favors a binary progenitor. Our observations also constrain the fraction of cosmic star formation in low-mass galaxies undetectable to Spitzer to be small at z < 4.

  16. THE SWIFT GRB HOST GALAXY LEGACY SURVEY. II. REST-FRAME NEAR-IR LUMINOSITY DISTRIBUTION AND EVIDENCE FOR A NEAR-SOLAR METALLICITY THRESHOLD

    SciTech Connect

    Perley, D. A.; Tanvir, N. R.; Hjorth, J.; Fynbo, J. P. U.; Krühler, T.; Laskar, T.; Berger, E.; Chary, R.; Postigo, A. de Ugarte; Michałowski, M. J.; Schulze, S.

    2016-01-20

    We present rest-frame near-IR (NIR) luminosities and stellar masses for a large and uniformly selected population of gamma-ray burst (GRB) host galaxies using deep Spitzer Space Telescope imaging of 119 targets from the Swift GRB Host Galaxy Legacy Survey spanning 0.03 < z < 6.3, and we determine the effects of galaxy evolution and chemical enrichment on the mass distribution of the GRB host population across cosmic history. We find a rapid increase in the characteristic NIR host luminosity between z ∼ 0.5 and z ∼ 1.5, but little variation between z ∼ 1.5 and z ∼ 5. Dust-obscured GRBs dominate the massive host population but are only rarely seen associated with low-mass hosts, indicating that massive star-forming galaxies are universally and (to some extent) homogeneously dusty at high redshift while low-mass star-forming galaxies retain little dust in their interstellar medium. Comparing our luminosity distributions with field surveys and measurements of the high-z mass–metallicity relation, our results have good consistency with a model in which the GRB rate per unit star formation is constant in galaxies with gas-phase metallicity below approximately the solar value but heavily suppressed in more metal-rich environments. This model also naturally explains the previously reported “excess” in the GRB rate beyond z ≳ 2; metals stifle GRB production in most galaxies at z < 1.5 but have only minor impact at higher redshifts. The metallicity threshold we infer is much higher than predicted by single-star models and favors a binary progenitor. Our observations also constrain the fraction of cosmic star formation in low-mass galaxies undetectable to Spitzer to be small at z < 4.

  17. Gas-rich galaxy pair unveiled in the lensed quasar 0957+561

    PubMed

    Planesas; Martin-Pintado; Neri; Colina

    1999-12-24

    Molecular gas in the host galaxy of the lensed quasar 0957+561 (QSO 0957+561) at the redshift of 1.41 has been detected in the carbon monoxide (CO) line. This detection shows the extended nature of the molecular gas distribution in the host galaxy and the pronounced lensing effects due to the differentially magnified CO luminosity at different velocities. The estimated mass of molecular gas is about 4 x 10(9) solar masses, a molecular gas mass typical of a spiral galaxy like the Milky Way. A second, weaker component of CO is interpreted as arising from a close companion galaxy that is rich in molecular gas and has remained undetected so far. Its estimated molecular gas mass is 1.4 x 10(9) solar masses, and its velocity relative to the main galaxy is 660 kilometers per second. The ability to probe the molecular gas distribution and kinematics of galaxies associated with high-redshift lensed quasars can be used to improve the determination of the Hubble constant H(0).

  18. SDSS-II Supernova survey. An analysis of the largest sample of type IA supernovae and correlations with host-galaxy spectral properties

    SciTech Connect

    Wolf, Rachel C.; D’Andrea, Chris B.; Gupta, Ravi R.; Sako, Masao; Fischer, John A.; Kessler, Rick; Jha, Saurabh W.; March, Marisa C.; Scolnic, Daniel M.; Fischer, Johanna-Laina; Campbell, Heather; Nichol, Robert C.; Olmstead, Matthew D.; Richmond, Michael; Schneider, Donald P.; Smith, Mathew

    2016-04-20

    Using the largest single-survey sample of Type Ia supernovae (SNe Ia) to date, we study the relationship between properties of SNe Ia and those of their host galaxies, focusing primarily on correlations with Hubble residuals (HR). Our sample consists of 345 photometrically-classified or spectroscopicallyconfirmed SNe Ia discovered as part of the SDSS-II Supernova Survey (SDSS-SNS). This analysis utilizes host-galaxy spectroscopy obtained during the SDSS-I/II spectroscopic survey and from an ancillary program on the SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS) that obtained spectra for nearly all host galaxies of SDSS-II SN candidates. In addition, we use photometric hostgalaxy properties from the SDSS-SNS data release (Sako et al. 2014) such as host stellar mass and star-formation rate. We confirm the well-known relation between HR and host-galaxy mass and find a 3.6σ significance of a non-zero linear slope. We also recover correlations between HR and hostgalaxy gas-phase metallicity and specific star-formation rate as they are reported in the literature. With our large dataset, we examine correlations between HR and multiple host-galaxy properties simultaneously and find no evidence of a significant correlation. We also independently analyze our spectroscopically-confirmed and photometrically-classified SNe Ia and comment on the significance of similar combined datasets for future surveys.

  19. EVIDENCE FOR COLD ACCRETION: PRIMITIVE GAS FLOWING ONTO A GALAXY AT z {approx} 0.274

    SciTech Connect

    Ribaudo, Joseph; Lehner, Nicolas; Christopher Howk, J.; Werk, Jessica K.; Xavier Prochaska, J.; Tumlinson, Jason

    2011-12-20

    We present UV and optical observations from the Cosmic Origins Spectrograph on the Hubble Space Telescope and Keck of a z = 0.27395 Lyman limit system (LLS) seen in absorption against the QSO PG1630+377. We detect H I absorption with log N(H I) = 17.06 {+-} 0.05 as well as Mg II, C III, Si III, and O VI in this system. The column densities are readily explained if this is a multi-phase system, with the intermediate and low ions arising in a very low metallicity ([Mg/H] = -1.71 {+-} 0.06) photoionized gas. We identify via Keck spectroscopy and Large Binocular Telescope imaging a 0.3 L{sub *} star-forming galaxy projected 37 kpc from the QSO at nearly identical redshift (z = 0.27406 and {Delta}v = -26 km s{sup -1}) with near solar metallicity ([O/H] = -0.20 {+-} 0.15). The presence of very low metallicity gas in the proximity of a near-solar metallicity, sub-L{sub *} galaxy strongly suggests that the LLS probes gas infalling onto the galaxy. A search of the literature reveals that such low-metallicity LLSs are not uncommon. We found that 50% (4/8) of the well-studied z {approx}< 1 LLSs have metallicities similar to the present system and show sub-L{sub *} galaxies with {rho} < 100 kpc in those fields where redshifts have been surveyed. We argue that the properties of these primitive LLSs and their host galaxies are consistent with those of cold mode accretion streams seen in galaxy simulations.

  20. Hubble space telescope observations of the afterglow, supernova, and host galaxy associated with the extremely bright GRB 130427A

    SciTech Connect

    Levan, A. J.; Tanvir, N. R.; Wiersema, K.; Fruchter, A. S.; Hounsell, R. A.; Graham, J.; Hjorth, J.; Fynbo, J. P. U.; Pian, E.; Mazzali, P.; Perley, D. A.; Cano, Z.; Cenko, S. B.; Kouveliotou, C.; Misra, K.

    2014-09-10

    We present Hubble Space Telescope (HST) observations of the exceptionally bright and luminous Swift gamma-ray burst (GRB), GRB 130427A. At z = 0.34, this burst affords an excellent opportunity to study the supernova (SN) and host galaxy associated with an intrinsically extremely luminous burst (E {sub iso} > 10{sup 54} erg): more luminous than any previous GRB with a spectroscopically associated SN. We use the combination of the image quality, UV capability, and invariant point-spread function of HST to provide the best possible separation of the afterglow, host, and SN contributions to the observed light ∼17 rest-frame days after the burst, utilizing a host subtraction spectrum obtained one year later. Advanced Camera for Surveys grism observations show that the associated SN, SN 2013cq, has an overall spectral shape and luminosity similar to SN 1998bw (with a photospheric velocity, v {sub ph} ∼ 15, 000 km s{sup –1}). The positions of the bluer features are better matched by the higher velocity SN 2010bh (v {sub ph} ∼ 30, 000 km s{sup –1}), but this SN is significantly fainter and fails to reproduce the overall spectral shape, perhaps indicative of velocity structure in the ejecta. We find that the burst originated ∼4 kpc from the nucleus of a moderately star forming (1 M {sub ☉} yr{sup –1}), possibly interacting disk galaxy. The absolute magnitude, physical size, and morphology of this galaxy, as well as the location of the GRB within it, are also strikingly similar to those of GRB 980425/SN 1998bw. The similarity of the SNe and environment from both the most luminous and least luminous GRBs suggests that broadly similar progenitor stars can create GRBs across six orders of magnitude in isotropic energy.

  1. Hubble Space Telescope Observations of the Afterglow, Supernova and Host Galaxy Associated with the Extremely Bright GRB 130427A

    NASA Technical Reports Server (NTRS)

    Levan, A.J.; Tanvir, N. R.; Fruchter, A. S.; Hjorth, J.; Pian, E.; Mazzali, P.; Hounsell, R. A.; Perley, D. A.; Cano, Z.; Graham, J.; Cenko, S. B.; Fynbo, J. P. U.; Kouveliotou, C.; Pe'er, A.; Misra, K.; Wiersema, K.

    2014-01-01

    We present Hubble Space Telescope (HST) observations of the exceptionally bright and luminous Swift gamma-ray burst, GRB 130427A. At z=0.34 this burst affords an excellent opportunity to study the supernova and host galaxy associated with an intrinsically extremely luminous burst (E(sub iso) greater than 10(exp 54) erg): more luminous than any previous GRB with a spectroscopically associated supernova. We use the combination of the image quality, UV capability and and invariant PSF of HST to provide the best possible separation of the afterglow, host and supernova contributions to the observed light approximately 17 rest-frame days after the burst utilising a host subtraction spectrum obtained 1 year later. Advanced Camera for Surveys (ACS) grism observations show that the associated supernova, SN 2013cq, has an overall spectral shape and luminosity similar to SN 1998bw (with a photospheric velocity, vph approximately 15,000 kilometers per second). The positions of the bluer features are better matched by the higher velocity SN 2010bh (vph approximately 30,000 kilometers per second), but SN 2010bh (vph approximately 30,000 kilometers per second but this SN is significantly fainter, and fails to reproduce the overall spectral shape, perhaps indicative of velocity structure in the ejecta. We find that the burst originated approximately 4 kpc from the nucleus of a moderately star forming (1 Solar Mass yr(exp-1)), possibly interacting disc galaxy. The absolute magnitude, physical size and morphology of this galaxy, as well as the location of the GRB within it are also strikingly similar to those of GRB980425SN 1998bw. The similarity of supernovae and environment from both the most luminous and least luminous GRBs suggests broadly similar progenitor stars can create GRBs across six orders of magnitude in isotropic energy.

  2. Hubble Space Telescope Observations of the Afterglow, Supernova, and Host Galaxy Associated with the Extremely Bright GRB 130427A

    NASA Astrophysics Data System (ADS)

    Levan, A. J.; Tanvir, N. R.; Fruchter, A. S.; Hjorth, J.; Pian, E.; Mazzali, P.; Hounsell, R. A.; Perley, D. A.; Cano, Z.; Graham, J.; Cenko, S. B.; Fynbo, J. P. U.; Kouveliotou, C.; Pe'er, A.; Misra, K.; Wiersema, K.

    2014-09-01

    We present Hubble Space Telescope (HST) observations of the exceptionally bright and luminous Swift gamma-ray burst (GRB), GRB 130427A. At z = 0.34, this burst affords an excellent opportunity to study the supernova (SN) and host galaxy associated with an intrinsically extremely luminous burst (E iso > 1054 erg): more luminous than any previous GRB with a spectroscopically associated SN. We use the combination of the image quality, UV capability, and invariant point-spread function of HST to provide the best possible separation of the afterglow, host, and SN contributions to the observed light ~17 rest-frame days after the burst, utilizing a host subtraction spectrum obtained one year later. Advanced Camera for Surveys grism observations show that the associated SN, SN 2013cq, has an overall spectral shape and luminosity similar to SN 1998bw (with a photospheric velocity, v ph ~ 15, 000 km s-1). The positions of the bluer features are better matched by the higher velocity SN 2010bh (v ph ~ 30, 000 km s-1), but this SN is significantly fainter and fails to reproduce the overall spectral shape, perhaps indicative of velocity structure in the ejecta. We find that the burst originated ~4 kpc from the nucleus of a moderately star forming (1 M ⊙ yr-1), possibly interacting disk galaxy. The absolute magnitude, physical size, and morphology of this galaxy, as well as the location of the GRB within it, are also strikingly similar to those of GRB 980425/SN 1998bw. The similarity of the SNe and environment from both the most luminous and least luminous GRBs suggests that broadly similar progenitor stars can create GRBs across six orders of magnitude in isotropic energy.

  3. Probing the Early Universe with the Epoch of Reionization and QSO Spectroscopy

    NASA Astrophysics Data System (ADS)

    Matejek, Michael Scott

    2012-06-01

    We present results from the first systematic survey for Mg II absorption lines at z > 2.5. Using 46 infrared QSO spectra we discovered 111 Mg II systems, including five with z > 5---the most distant systems now known. The comoving line density for weaker systems is statistically consistent with no evolution from z = 0.4 to z = 5.5. The density for stronger systems increases three-fold until z ˜ 3 before declining towards higher redshifts, suggesting a connection to star formation. The weaker systems' lack of evolution does not fit within this interpretation, but may be reproduced by extrapolating low redshift scaling relations between host galaxy luminosity and absorbing halo radius to earlier epochs. Using new measurements from optical spectra of the same targets and low redshift control samples we study evolutionary trends in the chemical composition of Mg II systems from z = 0 → 5.33. We observe a significant strengthening in the characteristic N(H I) for fixed Mg II strength as one moves toward higher redshift. We set lower limits on the metallicity where we can measure H I, and find that systems with Wl27960 = 0.3 - 1.0A are quite metal rich at ˜ 0.1 Solar. We speculate that if weaker Mg II systems represent accreting gas, then their high metal abundance suggests re-accretion of recently ejected material rather than first-time infall from the metal-poor IGM, even at early times. We present a new technique for simultaneously fitting bright point sources in ungridded visibility data called the side lobe matrix technique. We provide computational speedups which allow for real time implementation. We derive analytic approximations for the error distributions of fit intensities in the presence of thermal noise, imperfect calibration, and ionospheric errors. We find that the intensity errors of the brightest sources with imperfect calibration and ionospheric errors are dominated by 'self errors' that exist independent of sidelobe contamination. We demonstrate

  4. Discovery of a Damped Lyα Absorber at z = 3.3 along a Galaxy Sight-line in the SSA22 Field

    NASA Astrophysics Data System (ADS)

    Mawatari, K.; Inoue, A. K.; Kousai, K.; Hayashino, T.; Cooke, R.; Prochaska, J. X.; Yamada, T.; Matsuda, Y.

    2016-02-01

    Using galaxies as background light sources to map the Lyα absorption lines is a novel approach to study Damped Lyα Absorbers (DLAs). We report the discovery of an intervening z = 3.335 ± 0.007 DLA along a galaxy sight-line identified among 80 Lyman Break Galaxy (LBG) spectra obtained with our Very Large Telescope/Visible Multi-Object Spectrograph survey in the SSA22 field. The measured DLA neutral hydrogen (H i) column density is log(NH i/cm-2) = 21.68 ± 0.17. The DLA covering fraction over the extended background LBG is >70% (2σ), yielding a conservative constraint on the DLA area of ≳1 kpc2. Our search for a counterpart galaxy hosting this DLA concludes that there is no counterpart galaxy with star formation rate larger than a few M⊙ yr-1, ruling out an unobscured violent star formation in the DLA gas cloud. We also rule out the possibility that the host galaxy of the DLA is a passive galaxy with M* ≳ 5 × 1010M⊙ or a heavily dust-obscured galaxy with E(B - V) ≳ 2. The DLA may coincide with a large-scale overdensity of the spectroscopic LBGs. The occurrence rate of the DLA is compatible with that of DLAs found in QSO sight-lines.

  5. Nuclear Gas Dynamics of NGC2110: A Black Hole Offset from the Host Galaxy Mass Center?

    NASA Technical Reports Server (NTRS)

    Mundell, C. G.; Ferruit, P.; Nagar, N.; Wilson, A. S.

    2004-01-01

    It has been suggested that the central regions of many galaxies are unlikely to be in a static steady state, with instabilities caused by sinking satellites, the influence of a supermassive black hole or residuals of galaxy formation, resulting in the nuclear black hole orbiting the galaxy center. The observational signature of such an orbiting black hole is an offset of the active nucleus (AGN) from the kinematic center defined by the galaxy rotation curve. This orbital motion may provide fuel for the AGN, as the hole 'grazes' on the ISM, and bent radio jets, due to the motion of their source. The early type (E/SO) Seyfert galaxy, NGC2210, with its striking twin, 'S'-shaped radio jets, is a unique and valuable test case for the offset-nucleus phenomenon since, despite its remarkably normal rotation curve, its kinematically-measured mass center is displaced both spatially (260 pc) and kinematically (170 km/s) from the active nucleus located in optical and radio studies. However, the central kinematics, where the rotation curve rises most steeply, have been inaccessible with ground-based resolutions. We present new, high resolution WFPC2 imaging and long-slit STIS spectroscopy of the central 300 pc of NGC2110. We discuss the structure and kinematics of gas moving in the galactic potential on subarcsecond scales and the reality of the offset between the black hole and the galaxy mass center.

  6. The hydrogen-poor superluminous supernova iPTF 13ajg and its host galaxy in absorption and emission

    SciTech Connect

    Vreeswijk, Paul M.; Gal-Yam, Avishay; De Cia, Annalisa; Rubin, Adam; Yaron, Ofer; Tal, David; Ofek, Eran O.; Savaglio, Sandra; Quimby, Robert M.; Sullivan, Mark; Cenko, S. Bradley; Filippenko, Alexei V.; Clubb, Kelsey I.; Perley, Daniel A.; Cao, Yi; Taddia, Francesco; Sollerman, Jesper; Leloudas, Giorgos; Arcavi, Iair; Kasliwal, Mansi M.; and others

    2014-12-10

    We present imaging and spectroscopy of a hydrogen-poor superluminous supernova (SLSN) discovered by the intermediate Palomar Transient Factory, iPTF 13ajg. At a redshift of z = 0.7403, derived from narrow absorption lines, iPTF 13ajg peaked at an absolute magnitude of M {sub u,} {sub AB} = –22.5, one of the most luminous supernovae to date. The observed bolometric peak luminosity of iPTF 13ajg is 3.2 × 10{sup 44} erg s{sup –1}, while the estimated total radiated energy is 1.3 × 10{sup 51} erg. We detect narrow absorption lines of Mg I, Mg II, and Fe II, associated with the cold interstellar medium in the host galaxy, at two different epochs with X-shooter at the Very Large Telescope. From Voigt profile fitting, we derive the column densities log N(Mg I) =11.94 ± 0.06, log N(Mg II) =14.7 ± 0.3, and log N(Fe II) =14.25 ± 0.10. These column densities, as well as the Mg I and Mg II equivalent widths of a sample of hydrogen-poor SLSNe taken from the literature, are at the low end of those derived for gamma-ray bursts (GRBs) whose progenitors are also thought to be massive stars. This suggests that the environments of hydrogen-poor SLSNe and GRBs are different. From the nondetection of Fe II fine-structure absorption lines, we derive a lower limit on the distance between the supernova and the narrow-line absorbing gas of 50 pc. The neutral gas responsible for the absorption in iPTF 13ajg exhibits a single narrow component with a low velocity width, ΔV = 76 km s{sup –1}, indicating a low-mass host galaxy. No host galaxy emission lines are detected, leading to an upper limit on the unobscured star formation rate (SFR) of SFR{sub [O} {sub II]}<0.07M{sub ⊙}yr{sup −1}. Late-time imaging shows the iPTF 13ajg host galaxy to be faint, with g {sub AB} ≈ 27.0 and R {sub AB} ≥ 26.0 mag, corresponding to M {sub B,} {sub Vega} ≳ –17.7 mag.

  7. The Type Ia Supernova Color-Magnitude Relation and Host Galaxy Dust: A Simple Hierarchical Bayesian Model

    NASA Astrophysics Data System (ADS)

    Mandel, Kaisey; Scolnic, Daniel; Shariff, Hikmatali; Foley, Ryan; Kirshner, Robert

    2017-01-01

    Inferring peak optical absolute magnitudes of Type Ia supernovae (SN Ia) from distance-independent measures such as their light curve shapes and colors underpins the evidence for cosmic acceleration. SN Ia with broader, slower declining optical light curves are more luminous (“broader-brighter”) and those with redder colors are dimmer. But the “redder-dimmer” color-luminosity relation widely used in cosmological SN Ia analyses confounds its two separate physical origins. An intrinsic correlation arises from the physics of exploding white dwarfs, while interstellar dust in the host galaxy also makes SN Ia appear dimmer and redder. Conventional SN Ia cosmology analyses currently use a simplistic linear regression of magnitude versus color and light curve shape, which does not model intrinsic SN Ia variations and host galaxy dust as physically distinct effects, resulting in low color-magnitude slopes. We construct a probabilistic generative model for the dusty distribution of extinguished absolute magnitudes and apparent colors as the convolution of an intrinsic SN Ia color-magnitude distribution and a host galaxy dust reddening-extinction distribution. If the intrinsic color-magnitude (MB vs. B-V) slope βint differs from the host galaxy dust law RB, this convolution results in a specific curve of mean extinguished absolute magnitude vs. apparent color. The derivative of this curve smoothly transitions from βint in the blue tail to RB in the red tail of the apparent color distribution. The conventional linear fit approximates this effective curve near the average apparent color, resulting in an apparent slope βapp between βint and RB. We incorporate these effects into a hierarchical Bayesian statistical model for SN Ia light curve measurements, and analyze a dataset of SALT2 optical light curve fits of 277 nearby SN Ia at z < 0.10. The conventional linear fit obtains βapp ≈ 3. Our model finds a βint = 2.2 ± 0.3 and a distinct dust law of RB = 3.7 ± 0

  8. The Hydrogen-poor Superluminous Supernova iPTF 13ajg and its Host Galaxy in Absorption and Emission

    NASA Astrophysics Data System (ADS)

    Vreeswijk, Paul M.; Savaglio, Sandra; Gal-Yam, Avishay; De Cia, Annalisa; Quimby, Robert M.; Sullivan, Mark; Cenko, S. Bradley; Perley, Daniel A.; Filippenko, Alexei V.; Clubb, Kelsey I.; Taddia, Francesco; Sollerman, Jesper; Leloudas, Giorgos; Arcavi, Iair; Rubin, Adam; Kasliwal, Mansi M.; Cao, Yi; Yaron, Ofer; Tal, David; Ofek, Eran O.; Capone, John; Kutyrev, Alexander S.; Toy, Vicki; Nugent, Peter E.; Laher, Russ; Surace, Jason; Kulkarni, Shrinivas R.

    2014-12-01

    We present imaging and spectroscopy of a hydrogen-poor superluminous supernova (SLSN) discovered by the intermediate Palomar Transient Factory, iPTF 13ajg. At a redshift of z = 0.7403, derived from narrow absorption lines, iPTF 13ajg peaked at an absolute magnitude of M u, AB = -22.5, one of the most luminous supernovae to date. The observed bolometric peak luminosity of iPTF 13ajg is 3.2 × 1044 erg s-1, while the estimated total radiated energy is 1.3 × 1051 erg. We detect narrow absorption lines of Mg I, Mg II, and Fe II, associated with the cold interstellar medium in the host galaxy, at two different epochs with X-shooter at the Very Large Telescope. From Voigt profile fitting, we derive the column densities log N(Mg I) =11.94 ± 0.06, log N(Mg II) =14.7 ± 0.3, and log N(Fe II) =14.25 ± 0.10. These column densities, as well as the Mg I and Mg II equivalent widths of a sample of hydrogen-poor SLSNe taken from the literature, are at the low end of those derived for gamma-ray bursts (GRBs) whose progenitors are also thought to be massive stars. This suggests that the environments of hydrogen-poor SLSNe and GRBs are different. From the nondetection of Fe II fine-structure absorption lines, we derive a lower limit on the distance between the supernova and the narrow-line absorbing gas of 50 pc. The neutral gas responsible for the absorption in iPTF 13ajg exhibits a single narrow component with a low velocity width, ΔV = 76 km s-1, indicating a low-mass host galaxy. No host galaxy emission lines are detected, leading to an upper limit on the unobscured star formation rate (SFR) of SFR_[O \\scriptsize{II]}<0.07 {M_⊙ yr-1}. Late-time imaging shows the iPTF 13ajg host galaxy to be faint, with g AB ≈ 27.0 and R AB >= 26.0 mag, corresponding to M B, Vega >~ -17.7 mag.

  9. PROPERTIES OF GALAXIES HOSTING X-RAY-SELECTED ACTIVE GALACTIC NUCLEI IN THE CL1604 SUPERCLUSTER AT z = 0.9

    SciTech Connect

    Kocevski, Dale D.; Lubin, Lori M.; Lemaux, Brian C.; Gal, Roy R.; Fassnacht, Christopher D.; Lin, Robin; Squires, Gordon K.

    2009-08-01

    Recent galaxy evolution models suggest that feedback from active galactic nuclei (AGNs) may be responsible for suppressing star formation in their host galaxies and the subsequent migration of these systems onto the red sequence. To investigate the role of AGNs in driving the evolution of their hosts, we have carried out a study of the environments and optical properties of galaxies harboring X-ray luminous AGNs in the Cl1604 supercluster at z {approx} 0.9. Making use of Chandra, HST/ACS and Keck/DEIMOS observations, we examine the integrated colors, morphologies, and spectral properties of nine moderate-luminosity (L {sub X} {approx} 10{sup 43} erg s{sup -1}) type 2 Seyferts detected in the Cl1604 complex. We find that the AGNs are predominantly hosted by luminous spheroids and/or bulge-dominated galaxies which have colors that place them in the valley between the blue cloud and red sequence in color-magnitude space, consistent with predictions that AGN hosts should constitute a transition population. Half of the hosts have bluer overall colors as a result of blue resolved cores in otherwise red spheroids and a majority show signs of recent or pending interactions. We also find a substantial number exhibit strong Balmer absorption features indicative of post-starburst galaxies, despite the fact that we detect narrow [O II] emission lines in all of the host spectra. If the [O II] lines are due in part to AGN emission, as we suspect, then this result implies that a significant fraction of these galaxies (44%) have experienced an enhanced level of star formation within the last {approx}1 Gyr which was rapidly suppressed. Furthermore we observe that the hosts galaxies tend to avoid the densest regions of the supercluster and are instead located in intermediate density environments, such as the infall region of a massive cluster or in poorer systems undergoing assembly. Overall we find that the properties of the nine host galaxies are generally consistent with a

  10. HST Imaging of Fading AGN Candidates. I. Host-galaxy Properties and Origin of the Extended Gas

    NASA Astrophysics Data System (ADS)

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

    2015-05-01

    We present narrow- and medium-band Hubble Space Telescope imaging, with additional supporting ground-based imaging, spectrophotometry, and Fabry-Perot interferometric data, for eight galaxies identified as hosting a fading active galactic nucleus (AGN). These are selected to have AGN-ionized gas projected \\gt 10 kpc from the nucleus and energy budgets with a significant shortfall of ionizing radiation between the requirement to ionize the distant gas and the AGN as observed directly, indicating fading of the AGN on ≈50,000 yr timescales. This paper focuses on the host-galaxy properties and origin of the gas. In every galaxy, we identify evidence of ongoing or past interactions, including tidal tails, shells, and warped or chaotic dust structures; a similarly selected sample of obscured AGNs with extended ionized clouds shares this high incidence of disturbed morphologies. Several systems show multiple dust lanes in different orientations, broadly fit by differentially precessing disks of accreted material viewed ˜1.5 Gyr after its initial arrival. The host systems are of early Hubble type; most show nearly pure de Vaucouleurs surface brightness profiles and Sérsic indices appropriate for classical bulges, with one S0 and one SB0 galaxy. The gas has a systematically lower metallicity than the nuclei; three systems have abundances uniformly well below solar, consistent with an origin in tidally disrupted low-luminosity galaxies, while some systems have more nearly solar abundances (accompanied by such signatures as multiple Doppler components), which may suggest redistribution of gas by outflows within the host galaxies themselves. These aspects are consistent with a tidal origin for the extended gas in most systems, although the ionized gas and stellar tidal features do not always match closely. Unlike extended emission regions around many radio-loud AGNs, these clouds are kinematically dominated by rotation, in some cases in warped disks. Outflows can play

  11. IDENTIFYING THE LOCATION IN THE HOST GALAXY OF THE SHORT GRB 111117A WITH THE CHANDRA SUBARCSECOND POSITION

    SciTech Connect

    Sakamoto, T.; Troja, E.; Aoki, K.; Guiriec, S.; Barthelmy, S. D.; Im, M.; Jeon, Y.; Leloudas, G.; Malesani, D.; De Ugarte Postigo, A.; Andersen, M. I.; Melandri, A.; D'Avanzo, P.; Urata, Y.; Xu, D.; Gorosabel, J.; Sanchez-Ramirez, R.; Briggs, M. S.; Foley, S.; and others

    2013-03-20

    We present our successful Chandra program designed to identify, with subarcsecond accuracy, the X-ray afterglow of the short GRB 111117A, which was discovered by Swift and Fermi. Thanks to our rapid target of opportunity request, Chandra clearly detected the X-ray afterglow, though no optical afterglow was found in deep optical observations. The host galaxy was clearly detected in the optical and near-infrared band, with the best photometric redshift of z=1.31{sub -0.23}{sup +0.46} (90% confidence), making it one of the highest known short gamma-ray burst (GRB) redshifts. Furthermore, we see an offset of 1.0 {+-} 0.2 arcsec, which corresponds to 8.4 {+-} 1.7 kpc, between the host and the afterglow position. We discuss the importance of using Chandra for obtaining subarcsecond X-ray localizations of short GRB afterglows to study GRB environments.

  12. The low-extinction afterglow in the solar-metallicity host galaxy of γ-ray burst 110918A

    NASA Astrophysics Data System (ADS)

    Elliott, J.; Krühler, T.; Greiner, J.; Savaglio, S.; Olivares, F.; Rau, E. A.; de Ugarte Postigo, A.; Sánchez-Ramírez, R.; Wiersema, K.; Schady, P.; Kann, D. A.; Filgas, R.; Nardini, M.; Berger, E.; Fox, D.; Gorosabel, J.; Klose, S.; Levan, A.; Nicuesa Guelbenzu, A.; Rossi, A.; Schmidl, S.; Sudilovsky, V.; Tanvir, N. R.; Thöne, C. C.

    2013-08-01

    Galaxies selected through long γ-ray bursts (GRBs) could be of fundamental importance when mapping the star formation history out to the highest redshifts. Before using them as efficient tools in the early Universe, however, the environmental factors that govern the formation of GRBs need to be understood. Metallicity is theoretically thought to be a fundamental driver in GRB explosions and energetics, but it is still, even after more than a decade of extensive studies, not fully understood. This is largely related to two phenomena: a dust-extinction bias, which prevented high-mass and thus likely high-metallicity GRB hosts from being detected in the first place, and a lack of efficient instrumentation, which limited spectroscopic studies, including metallicity measurements, to the low-redshift end of the GRB host population. The subject of this work is the very energetic GRB 110918A (Eγ,iso = 1.9 × 1054 erg), for which we measure a redshift of z = 0.984. GRB 110918A gave rise to a luminous afterglow with an intrinsic spectral slope of β = 0.70, which probed a sight-line with little extinction (AGRBV = 0.16 mag) and soft X-ray absorption (NH,X = (1.6 ± 0.5) × 1021 cm-2) typical of the established distributions of afterglow properties. However, photometric and spectroscopic follow-up observations of the galaxy hosting GRB 110918A, including optical/near-infrared photometry with the Gamma-Ray burst Optical Near-infrared Detector and spectroscopy with the Very Large Telescope/X-shooter, reveal an all but average GRB host in comparison to the z ~ 1 galaxies selected through similar afterglows to date. It has a large spatial extent with a half-light radius of R1/2 ~ 10 kpc, the highest stellar mass for z < 1.9 (log (M∗/M⊙) = 10.68 ± 0.16), and an Hα-based star formation rate of SFRHα = 41+28-16M⊙ yr-1. We measure a gas-phase extinction of AgasV ~ 1.8 mag through the Balmer decrement and one of the largest host-integrated metallicities ever of around solar

  13. On the afterglow and host galaxy of GRB 021004: A comprehensivestudy with the Hubble Space Telescope1

    SciTech Connect

    Fynbo, J.P.U.; Gorosabel, J.; Smette, A.; Fruchter, A.; Hjorth,J.; Pedersen, K.; Levan, A.; Burud, I.; Sahu, K.; Vreeswijk, P.M.; Bergeron, E.; Kouveliotou1, C.; Tanvir, N.; Thorsett11, S.E.; Wijers,R.A.M.J.; Castro Ceron, J.M.; Castro-Tirado, A.; Garnavich, P.; Holland,S.T.; Jakobsson, P.; Moller, P.; Nugent, P.; Pian, E.; Rhoads, J.; Thomsen, B.; Watson, D.; Woosley, S.

    2004-12-01

    We report on Hubble Space Telescope (HST) observations of the late-time afterglow and host galaxy of GRB 021004 (z = 2.33).Although this gamma-ray burst (GRB) is one of the best observed so far in terms of sampling in the time domain, multi-wavelength coverage and polarimetric observations, there is large disagreement between different measurements and interpretations of this burst in the literature. We have observed the field of GRB 021004 with the HST at multiple epochs from 3 days until almost 10 months after the burst. With STI S prism and G430L spectroscopy we cover the spectral region from about 2000 Angstrom to 5700 Angstrom corresponding to 600 1700 Angstrom in the rest frame. From the limit on the flux recovery bluewards of the Lyman-limit we constrain the H I column density to be above 1 x 1018 cm-2 (5 sigma). Based on ACS and N ICMOS imaging we find that the afterglow evolved a chromatically within the errors (any variation must be less then 5 percent) during the period of HST observations. The color changes observed by other authors during the first four days must be related to a 'noisy' phenomenon superimposed on an afterglow component with a constant spectral shape. This also means that the cooling break has remained on the blue side of the optical part of the spectrum for at least two weeks after the explosion. The optical to X-ray slope OX is consistent with being the same at 1.4 and 52.4 days after the burst. This indicates that the cooling frequency is constant and hence, according to fireball models, that the circumburst medium has a constant density profile. The late-time slope of the light curve (alpha 2, F nu proportional to t-alpha2) is in the range 2 = 1.8-1.9, although inconsistent with a single power-law. This could be due to a late-time flattening caused by the transition to non-relativistic expansion or due to excess emission (a 'bump' in the light curve) about 7 days afterburst. The host galaxy is like most previously studied GRB hosts

  14. Spitzer Observations of a Gravitationally Lensed Quasar, QSO 2237+0305

    NASA Astrophysics Data System (ADS)

    Agol, Eric; Gogarten, Stephanie M.; Gorjian, Varoujan; Kimball, Amy

    2009-06-01

    The four-image gravitationally lensed quasar QSO 2237+0305 is microlensed by stars in the lens galaxy. The amplitude of microlensing variability can be used to infer the relative size of the quasar as a function of wavelength; this provides a test of quasar models. Toward this end, we present Spitzer Space Telescope Infrared Spectrograph and Infrared Array Camera (IRAC) observations of QSO 2237+0305, finding the following. (1) The infrared (IR) spectral energy distribution (SED) is similar to that of other bright radio-quiet quasars, contrary to an earlier claim. (2) A dusty torus model with a small opening angle fits the overall shape of the IR SED well, but the quantitative agreement is poor due to an offset in wavelength of the silicate feature. (3) The flux ratios of the four lensed images can be derived from the IRAC data despite being unresolved. We find that the near-IR fluxes are increasingly affected by microlensing toward shorter wavelengths. (4) The wavelength dependence of the IRAC flux ratios is consistent with the standard quasar model in which an accretion disk and a dusty torus both contribute near 1 μm in the rest frame. This is also consistent with recent IR spectropolarimetry of nearby quasars.

  15. MUSE Reveals a Recent Merger in the Post-starburst Host Galaxy of the TDE ASASSN-14li

    NASA Astrophysics Data System (ADS)

    Prieto, J. L.; Krühler, T.; Anderson, J. P.; Galbany, L.; Kochanek, C. S.; Aquino, E.; Brown, J. S.; Dong, Subo; Förster, F.; Holoien, T. W.-S.; Kuncarayakti, H.; Maureira, J. C.; Rosales-Ortega, F. F.; Sánchez, S. F.; Shappee, B. J.; Stanek, K. Z.

    2016-10-01

    We present Multi Unit Spectroscopic Explorer (MUSE) integral field spectroscopic observations of the host galaxy (PGC 043234) of one of the closest (z = 0.0206, D ≃ 90 Mpc) and best-studied tidal disruption events (TDEs), ASASSN-14li. The MUSE integral field data reveal asymmetric and filamentary structures that extend up to ≳10 kpc from the post-starburst host galaxy of ASASSN-14li. The structures are traced only through the strong nebular [O iii] λ5007, [N ii] λ6584, and Hα emission lines. The total off-nuclear [O iii] λ5007 luminosity is 4.7 × 1039 erg s-1, and the ionized H mass is ˜ {10}4(500/{n}{{e}}) {M}⊙ . Based on the Baldwin-Phillips-Terlevich diagram, the nebular emission can be driven by either AGN photoionization or shock excitation, with AGN photoionization favored given the narrow intrinsic line widths. The emission line ratios and spatial distribution strongly resemble ionization nebulae around fading AGNs such as IC 2497 (Hanny's Voorwerp) and ionization “cones” around Seyfert 2 nuclei. The morphology of the emission line filaments strongly suggest that PGC 043234 is a recent merger, which likely triggered a strong starburst and AGN activity leading to the post-starburst spectral signatures and the extended nebular emission line features we see today. We briefly discuss the implications of these observations in the context of the strongly enhanced TDE rates observed in post-starburst galaxies and their connection to enhanced theoretical TDE rates produced by supermassive black hole binaries.

  16. GRB 090417B and its Host Galaxy: A Step Towards an Understanding of Optically-Dark Gamma-Ray Bursts

    NASA Technical Reports Server (NTRS)

    Holland, Stephen T.; Sbarufatti, Boris; Shen, Rongfeng; Schady, Patricia; Cummings, Jay R.; Fonseca, Emmanuel; Fynbo, Johan P. U.; Jakobsson, Pall; Leitet, Elisabet; Linne, Staffan; Roming, Peter W.A.; Still, Martin; Zhang, Bing

    2009-01-01

    GRB 090417B was an unusually long burst with a T(sub 90) duration of at least 2130 s and a multi-peaked light curve at energies of 15-150 keV. It was optically dark and has been convincingly associated with a bright star-forming galaxy at a redshift of 0.345 that is broadly similar to the Milky Way. This is one of the few cases where a host galaxy has been clearly identified for a dark gamma-ray burst and thus an ideal candidate for studying the origin of dark bursts. We find that the dark nature of GRB 090417B can not be explained by high redshift, incomplete observations, or unusual physics in the production of the afterglow. The Swift/XRT X-ray data are consistent with the afterglow being obscured by a dense, localized sheet of dust approximately 30-80 pc from the burst along the line of sight. Assuming the standard relativistic fireball model for the afterglow we find that the optical flux is at least 2.5 mag fainter than predicted by the X -ray flux. We are able to explain the lack of an optical afterglow, and the evolution of the X -ray spectrum, by assuming that there is a sheet of dust along the line of sight approximately 30-80 pc from the progenitor. Our results suggest that this dust sheet imparts an extinction of A(sub v)> or = 12 mag, which is sufficient to explain the missing optical flux. GRB 090417B is an example of a gamma-ray burst that is dark due to the localized dust structure in its host galaxy.

  17. Optical Identification of Cepheids in 19 Host Galaxies of Type Ia Supernovae and NGC 4258 with the Hubble Space Telescope

    NASA Astrophysics Data System (ADS)

    Hoffmann, Samantha L.; Macri, Lucas M.; Riess, Adam G.; Yuan, Wenlong; Casertano, Stefano; Foley, Ryan J.; Filippenko, Alexei V.; Tucker, Brad E.; Chornock, Ryan; Silverman, Jeffrey M.; Welch, Douglas L.; Goobar, Ariel; Amanullah, Rahman

    2016-10-01

    We present results of an optical search conducted as part of the SH0ES project (Supernovae and H0 for the Equation of State of dark energy) for Cepheid variable stars using the Hubble Space Telescope (HST) in 19 hosts of Type Ia supernovae (SNe Ia) and the maser-host galaxy NGC 4258. The targets include nine newly imaged SN Ia hosts using a novel strategy based on a long-pass filter that minimizes the number of HST orbits required to detect and accurately determine Cepheid properties. We carried out a homogeneous reduction and analysis of all observations, including new universal variability searches in all SN Ia hosts, which yielded a total of 2200 variables with well-defined selection criteria, the largest such sample identified outside the Local Group. These objects are used in a companion paper to determine the local value of H0 with a total uncertainty of 2.4%. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555.

  18. Observation of Weak Low-ionization Winds in Host Galaxies of Low Luminosity Active Galactic Nuclei at z ~1

    NASA Astrophysics Data System (ADS)

    Yesuf, Hassen; David C. Koo, S. M. Faber, J. Xavier Prochaska, Yicheng Guo, F. S. Liu, Emily C. Cunningham, Alison L. Coil, Puragra Guhathakurta

    2017-01-01

    A key physical manifestation of active galactic nuclei (AGN) feedback is predicted to be powerful galactic winds. However, the relative roles between AGN activity and star formation in driving such winds remain largely unexplored at high redshifts, near the peak of cosmic activity for both. We study winds in 12 X-ray AGN host galaxies at z ~ 1 in the CANDELS fields using deep Keck rest-frame UV spectroscopy. We find, using the low-ionization Fe II 2586 absorption in the stacked spectra, that the AGN show a median centroid velocity shift of -137 km/s and a median velocity dispersion of 103 km/ s. The centroid velocity and the velocity dispersions are obtained from a two component (ISM+wind) absorption line model. For comparison, a star-forming and X-ray undetected galaxies at a similar redshift, matched roughly in stellar mass and galaxy inclination, show the outflows to have a median centroid velocity of -135 km/s and a median velocity dispersion of 140 km/s. Thus, winds in the AGN are similar in velocities to those found in star-formation-driven winds, and are weak to escape and expel substantial cool gas from galaxies. A joint reanalysis of the z ~ 0.5 AGN sample and our sample yields a centroid velocity of -139 (+48, -87) km/s and a velocity dispersion of 82 (+47,-37) km/s. For the combined sample, about half the total equivalent width of the Fe II 2586 absorption is due to the wind. We do not observe winds with bulk velocities greater than 500 km/s predicted by some AGN feedback models.

  19. ALMA observations of the host galaxy of GRB 090423 at z = 8.23: deep limits on obscured star formation 630 million years after the big bang

    SciTech Connect

    Berger, E.; Zauderer, B. A.; Chary, R.-R.; Laskar, T.; Chornock, R.; Davies, J. E.; Tanvir, N. R.; Stanway, E. R.; Levan, A. J.; Levesque, E. M.

    2014-12-01

    We present rest-frame far-infrared (FIR) and optical observations of the host galaxy of GRB 090423 at z = 8.23 from the Atacama Large Millimeter Array (ALMA) and the Spitzer Space Telescope, respectively. The host remains undetected to 3σ limits of F {sub ν}(222 GHz) ≲ 33 μJy and F {sub ν}(3.6 μm) ≲ 81 nJy. The FIR limit is about 20 times fainter than the luminosity of the local ULIRG Arp 220 and comparable to the local starburst M 82. Comparing this with model spectral energy distributions, we place a limit on the infrared (IR) luminosity of L {sub IR}(8-1000 μm) ≲ 3 × 10{sup 10} L {sub ☉}, corresponding to a limit on the obscured star formation rate of SFR{sub IR}≲5 M {sub ☉} yr{sup –1}. For comparison, the limit on the unobscured star formation rate from Hubble Space Telescope rest-frame ultraviolet (UV) observations is SFR{sub UV} ≲ 1 M {sub ☉} yr{sup –1}. We also place a limit on the host galaxy stellar mass of M {sub *} ≲ 5 × 10{sup 7} M {sub ☉} (for a stellar population age of 100 Myr and constant star formation rate). Finally, we compare our millimeter observations to those of field galaxies at z ≳ 4 (Lyman break galaxies, Lyα emitters, and submillimeter galaxies) and find that our limit on the FIR luminosity is the most constraining to date, although the field galaxies have much larger rest-frame UV/optical luminosities than the host of GRB 090423 by virtue of their selection techniques. We conclude that GRB host galaxies at z ≳ 4, especially those with measured interstellar medium metallicities from afterglow spectroscopy, are an attractive sample for future ALMA studies of high redshift obscured star formation.

  20. Connecting GRBs and ULIRGs: A Sensitive, Unbiased Survey for Radio Emission from Gamma-Ray Burst Host Galaxies at 0 < z < 2.5

    NASA Astrophysics Data System (ADS)

    Perley, D. A.; Perley, R. A.; Hjorth, J.; Michałowski, M. J.; Cenko, S. B.; Jakobsson, P.; Krühler, T.; Levan, A. J.; Malesani, D.; Tanvir, N. R.

    2015-03-01

    Luminous infrared galaxies and submillimeter galaxies contribute significantly to stellar mass assembly and provide an important test of the connection between the gamma-ray burst (GRB) rate and that of overall cosmic star formation. We present sensitive 3 GHz radio observations using the Karl G. Jansky Very Large Array of 32 uniformly selected GRB host galaxies spanning a redshift range from 0 < z < 2.5, providing the first fully dust- and sample-unbiased measurement of the fraction of GRBs originating from the universe's most bolometrically luminous galaxies. Four galaxies are detected, with inferred radio star formation rates (SFRs) ranging between 50 and 300 M ⊙ yr-1. Three of the four detections correspond to events consistent with being optically obscured "dark" bursts. Our overall detection fraction implies that between 9% and 23% of GRBs between 0.5 < z < 2.5 occur in galaxies with S 3GHz > 10 μJy, corresponding to SFR > 50 M ⊙ yr-1 at z ~ 1 or >250 M ⊙ yr-1 at z ~ 2. Similar galaxies contribute approximately 10%-30% of all cosmic star formation, so our results are consistent with a GRB rate that is not strongly biased with respect to the total SFR of a galaxy. However, all four radio-detected hosts have stellar masses significantly lower than IR/submillimeter-selected field galaxies of similar luminosities. We suggest that the GRB rate may be suppressed in metal-rich environments but independently enhanced in intense starbursts, producing a strong efficiency dependence on mass but little net dependence on bulk galaxy SFR.

  1. CONNECTING GRBs AND ULIRGs: A SENSITIVE, UNBIASED SURVEY FOR RADIO EMISSION FROM GAMMA-RAY BURST HOST GALAXIES AT 0 < z < 2.5

    SciTech Connect

    Perley, D. A.; Perley, R. A.; Hjorth, J.; Malesani, D.; Michałowski, M. J.; Cenko, S. B.; Krühler, T.; Levan, A. J.; Tanvir, N. R.

    2015-03-10

    Luminous infrared galaxies and submillimeter galaxies contribute significantly to stellar mass assembly and provide an important test of the connection between the gamma-ray burst (GRB) rate and that of overall cosmic star formation. We present sensitive 3 GHz radio observations using the Karl G. Jansky Very Large Array of 32 uniformly selected GRB host galaxies spanning a redshift range from 0 < z < 2.5, providing the first fully dust- and sample-unbiased measurement of the fraction of GRBs originating from the universe's most bolometrically luminous galaxies. Four galaxies are detected, with inferred radio star formation rates (SFRs) ranging between 50 and 300 M {sub ☉} yr{sup –1}. Three of the four detections correspond to events consistent with being optically obscured 'dark' bursts. Our overall detection fraction implies that between 9% and 23% of GRBs between 0.5 < z < 2.5 occur in galaxies with S {sub 3GHz} > 10 μJy, corresponding to SFR > 50 M {sub ☉} yr{sup –1} at z ∼ 1 or >250 M {sub ☉} yr{sup –1} at z ∼ 2. Similar galaxies contribute approximately 10%-30% of all cosmic star formation, so our results are consistent with a GRB rate that is not strongly biased with respect to the total SFR of a galaxy. However, all four radio-detected hosts have stellar masses significantly lower than IR/submillimeter-selected field galaxies of similar luminosities. We suggest that the GRB rate may be suppressed in metal-rich environments but independently enhanced in intense starbursts, producing a strong efficiency dependence on mass but little net dependence on bulk galaxy SFR.

  2. PS1-10bzj: A FAST, HYDROGEN-POOR SUPERLUMINOUS SUPERNOVA IN A METAL-POOR HOST GALAXY

    SciTech Connect

    Lunnan, R.; Chornock, R.; Berger, E.; Milisavljevic, D.; Drout, M.; Sanders, N. E.; Challis, P. M.; Czekala, I.; Foley, R. J.; Fong, W.; Kirshner, R. P.; Leibler, C.; Marion, G. H.; Narayan, G.; Huber, M. E.; McCrum, M.; Smartt, S. J.; Rest, A.; Roth, K. C.; Scolnic, D.; and others

    2013-07-10

    We present observations and analysis of PS1-10bzj, a superluminous supernova (SLSN) discovered in the Pan-STARRS Medium Deep Survey at a redshift z = 0.650. Spectroscopically, PS1-10bzj is similar to the hydrogen-poor SLSNe 2005ap and SCP 06F6, though with a steeper rise and lower peak luminosity (M{sub bol} {approx_equal} -21.4 mag) than previous events. We construct a bolometric light curve, and show that while PS1-10bzj's energetics were less extreme than previous events, its luminosity still cannot be explained by radioactive nickel decay alone. We explore both a magnetar spin-down and circumstellar interaction scenario and find that either can fit the data. PS1-10bzj is located in the Extended Chandra Deep Field South and the host galaxy is imaged in a number of surveys, including with the Hubble Space Telescope. The host is a compact dwarf galaxy (M{sub B} Almost-Equal-To -18 mag, diameter {approx}< 800 pc), with a low stellar mass (M{sub *} Almost-Equal-To 2.4 Multiplication-Sign 10{sup 7} M{sub Sun }), young stellar population ({tau}{sub *} Almost-Equal-To 5 Myr), and a star formation rate of {approx}2-3 M{sub Sun} yr{sup -1}. The specific star formation rate is the highest seen in an SLSN host so far ({approx}100 Gyr{sup -1}). We detect the [O III] {lambda}4363 line, and find a low metallicity: 12 + (O/H) = 7.8 {+-} 0.2 ({approx_equal} 0.1 Z{sub Sun }). Together, this indicates that at least some of the progenitors of SLSNe come from young, low-metallicity populations.

  3. Metallicities in long gamma-ray burst host galaxies at z < 0.5 calculated by the detailed modelling of optical and infrared line ratios

    NASA Astrophysics Data System (ADS)

    Contini, M.

    2017-04-01

    We revisit the line spectra emitted from long gamma-ray burst (LGRB) host galaxies at z ≤ 0.5 in order to calculate, through the detailed modelling of line ratios, the physical conditions and relative abundances in LGRB hosts in this redshift range. We have found lower metallicities than in LGRB hosts at higher z. New results regarding the metallicities and physical conditions in different regions throughout the LGRB 980425 host at z = 0.0085 are presented. In particular, we have found that the effective starburst temperature in the supernova (SN) region is the highest in the entire host galaxy. The low ionization parameter reveals that the radiation source is far away, or is somehow prevented from reaching the emitting gas in the SN region. Models constrained by a few oxygen, nitrogen and sulphur line ratios to Hβ in the LGRB 980425 host reproduce the He II/Hβ and [Ar III]/Hβ line ratios satisfactorily. Modelling of the observed [S IV]10.51 μm/[S III]18.71 μm and [Ne III]10.6 μm/[Ne II]12.81 μm line ratios from the LGRB 031203 host galaxy at z = 0.105 shows that the mid-infrared lines are emitted from geometrically thin shock-dominated filaments that are not reached by photoionizing flux, while the optical lines are emitted from radiation-dominated outflowing clouds.

  4. THE OPTICALLY UNBIASED GRB HOST (TOUGH) SURVEY. VI. RADIO OBSERVATIONS AT z {approx}< 1 AND CONSISTENCY WITH TYPICAL STAR-FORMING GALAXIES

    SciTech Connect

    Michalowski, M. J.; Dunlop, J. S.; Kamble, A.; Kaplan, D. L.; Hjorth, J.; Malesani, D.; Fynbo, J. P. U.; Kruehler, T.; Reinfrank, R. F.; Bonavera, L.; Ibar, E.; Garrett, M. A.; Jakobsson, P.; Levan, A. J.; Massardi, M.; Pal, S.; Sollerman, J.; Tanvir, N. R.; Van der Horst, A. J.; and others

    2012-08-20

    The objective of this paper is to determine the level of obscured star formation activity and dust attenuation in a sample of gamma-ray burst (GRB) hosts, and to test the hypothesis that GRB hosts have properties consistent with those of the general star-forming galaxy populations. We present a radio continuum survey of all z < 1 GRB hosts in The Optically Unbiased GRB Host (TOUGH) sample supplemented with radio data for all (mostly pre-Swift) GRB-SN hosts discovered before 2006 October. We present new radio data for 22 objects and have obtained a detection for three of them (GRB 980425, 021211, 031203; none in the TOUGH sample), increasing the number of radio-detected GRB hosts from two to five. The star formation rate (SFR) for the GRB 021211 host of {approx}825 M{sub Sun} yr{sup -1}, the highest ever reported for a GRB host, places it in the category of ultraluminous infrared galaxies. We found that at least {approx}63% of GRB hosts have SFR < 100 M{sub Sun} yr{sup -1} and at most {approx}8% can have SFR > 500 M{sub Sun} yr{sup -1}. For the undetected hosts the mean radio flux (<35 {mu}Jy 3{sigma}) corresponds to an average SFR < 15 M{sub Sun} yr{sup -1}. Moreover, {approx}> 88% of the z {approx}< 1 GRB hosts have ultraviolet dust attenuation A{sub UV} < 6.7 mag (visual attenuation A{sub V} < 3 mag). Hence, we did not find evidence for large dust obscuration in a majority of GRB hosts. Finally, we found that the distributions of SFRs and A{sub UV} of GRB hosts are consistent with those of Lyman break galaxies, H{alpha} emitters at similar redshifts, and of galaxies from cosmological simulations. The similarity of the GRB population with other star-forming galaxies is consistent with the hypothesis that GRBs, a least at z {approx}< 1, trace a large fraction of all star formation, and are therefore less biased indicators than once thought.

  5. NEAR-INFRARED IMAGING OF A z = 6.42 QUASAR HOST GALAXY WITH THE HUBBLE SPACE TELESCOPE WIDE FIELD CAMERA 3

    SciTech Connect

    Mechtley, M.; Windhorst, R. A.; Cohen, S. H.; Jansen, R. A.; Scannapieco, E.; Ryan, R. E.; Koekemoer, A. M.; Schneider, G.; Fan, X.; Hathi, N. P.; Keel, W. C.; Roettgering, H.; Schneider, D. P.; Strauss, M. A.; Yan, H. J.

    2012-09-10

    We report on deep near-infrared F125W (J) and F160W (H) Hubble Space Telescope Wide Field Camera 3 images of the z = 6.42 quasar J1148+5251 to attempt to detect rest-frame near-ultraviolet emission from the host galaxy. These observations included contemporaneous observations of a nearby star of similar near-infrared colors to measure temporal variations in the telescope and instrument point-spread function (PSF). We subtract the quasar point source using both this direct PSF and a model PSF. Using direct subtraction, we measure an upper limit for the quasar host galaxy of m{sub J} > 22.8 and m{sub H} > 23.0 AB mag (2 {sigma}). After subtracting our best model PSF, we measure a limiting surface brightness from 0.''3 to 0.''5 radius of {mu}{sub J} > 23.5 and {mu}{sub H} > 23.7 AB mag arcsec{sup -2} (2 {sigma}). We test the ability of the model subtraction method to recover the host galaxy flux by simulating host galaxies with varying integrated magnitude, effective radius, and Sersic index, and conducting the same analysis. These models indicate that the surface brightness limit ({mu}{sub J} > 23.5 AB mag arcsec{sup -2}) corresponds to an integrated upper limit of m{sub J} > 22-23 AB mag, consistent with the direct subtraction method. Combined with existing far-infrared observations, this gives an infrared excess log (IRX) > 1.0 and corresponding ultraviolet spectral slope {beta} > -1.2 {+-} 0.2. These values match those of most local luminous infrared galaxies, but are redder than those of almost all local star-forming galaxies and z {approx_equal} 6 Lyman break galaxies.

  6. Scaling relations between black holes and their host galaxies: comparing theoretical and observational measurements, and the impact of selection effects

    NASA Astrophysics Data System (ADS)

    DeGraf, C.; Di Matteo, T.; Treu, T.; Feng, Y.; Woo, J.-H.; Park, D.

    2015-11-01

    We use the high-resolution simulation MassiveBlackII to examine scaling relations between black hole (BH) mass and host galaxy properties (σ, total M* and LV), finding good agreement with recent observational data, especially at the high-mass end. We find Gaussian intrinsic scatter (˜half the observed scatter) about all three relations, except among the most massive objects. Below z ˜ 2 the slope of the relations remain roughly z-independent, and only steepen by 50 per cent by z ˜ 4. The normalization of the σ, LV relations evolve by 0.3, 0.43 dex, while the M* correlation does not evolve out to at least z ˜ 2. Testing for selection biases, we find MBH- or M*-selected samples have steeper slopes than random samples, suggesting a constant-mass selection function can exhibit faster evolution than a random sample. We find a potential bias among high-LBH subsamples due to their more massive hosts, but that bright (active) active galactic nuclei exhibit no intrinsic bias relative to fainter (inactive) BHs in equivalent-mass hosts. Finally, we show that BHs below the local relation tend to grow faster than their host (72 per cent of BHs >0.3 dex below the mean relation have an MBH-M* trajectory steeper than the local relation), while those above have shallower trajectories (only 14 per cent are steeper than local). Thus BHs tend to grow faster than their hosts until surpassing the local relation, when their growth is suppressed, bringing them back towards the mean relation.

  7. ALMA Observations Show Major Mergers Among the Host Galaxies of Fast-growing, High-redshift​ Supermassive​ Black Holes

    NASA Astrophysics Data System (ADS)

    Trakhtenbrot, Benny; Lira, Paulina; Netzer, Hagai; Cicone, Claudia; Maiolino, Roberto; Shemmer, Ohad

    2017-02-01

    We present new ALMA band-7 data for a sample of six luminous quasars at z≃ 4.8, powered by fast-growing supermassive black holes (SMBHs) with rather uniform properties: the typical accretion rates and black hole masses are L/{L}{Edd}≃ 0.7 and {M}{BH}≃ {10}9 {M}ȯ . Our sample consists of three “FIR-bright” sources, which were individually detected in previous Herschel/SPIRE observations, with star formation rates of {SFR}> 1000 {M}ȯ {{yr}}-1, and three “FIR-faint” sources for which Herschel stacking analysis implies a typical SFR of ∼400 {M}ȯ {{yr}}-1. The dusty interstellar medium in the hosts of all six quasars is clearly detected in the ALMA data and resolved on scales of ∼2 kpc, in both continuum ({λ }{rest}∼ 150 μ {{m}}) and [{{C}} {{II}}] λ 157.74 μ {{m}} line emission. The continuum emission is in good agreement with the expectations from the Herschel data, confirming the intense SF activity in the quasar hosts. Importantly, we detect companion sub-millimeter galaxies (SMGs) for three sources—one FIR-bright and two FIR-faint, separated by ∼ 14{--}45 {kpc} and < 450 {km} {{{s}}}-1 from the quasar hosts. The [{{C}} {{II}}]-based dynamical mass estimates for the interacting SMGs are within a factor of ∼3 of the quasar hosts’ masses, while the continuum emission implies {{SFR}}{quasar}∼ (2{--}11)× {{SFR}}{SMG}. Our ALMA data therefore clearly support the idea that major mergers are important drivers for rapid early SMBH growth. However, the fact that not all high-SFR quasar hosts are accompanied by interacting SMGs and the gas kinematics as observed by ALMA suggest that other processes may be fueling these systems. Our analysis thus demonstrates the diversity of host galaxy properties and gas accretion mechanisms associated with early and rapid SMBH growth.

  8. Spectroscopy of supernova host galaxies from the SDSS-II SN survey with the SDSS and BOSS spectrographs

    NASA Astrophysics Data System (ADS)

    Olmstead, Matthew Dwaune

    Type Ia supernovae (SNeIa) have been used as standard candles to measure cosmological distances. The initial discovery of the accelerated expansion of the universe was performed using ~50 SNe Ia. Large SNe surveys have increased the number of spectroscopically-confirmed SNe Ia to over a thousand with redshift coverage beyond z = 1. We are now in the age of abundant photometry without the ability for full follow-up spectroscopy of all SN candidates. SN cosmology using these large samples will increasingly rely on robust photometric classification of SN candidates. Photometric classification will increase the sample by including faint SNe as these are preferentially not observed with follow-up spectroscopy. The primary concern with using photometrically classified SNe Ia in cosmology is when a core-collapse SNe is incorrectly classified as an SN Ia. This can be mitigated by obtaining the host galaxy redshift of each SN candidate and using this information as a prior in the photometric classification, removing one degree of freedom. To test the impact of redshift on photometric classification, I have performed an assessment on photometric classification of candidates from the Sloan Digital Sky Survey-II (SDSS-II) SN Survey. I have tested the classification with and without redshift priors by looking at the change of photometric classification, the effect of data quality on photometric classification, and the effect of SN light curve properties on photometric classification. Following our suggested classification scheme, there are a total of 1038 photometrically classified SNe Ia when using a flat redshift prior and 1002 SNe~Ia with the spectroscopic redshift. For 912 (91.0%) candidates classified as likely SNe Ia without redshift information, the classification is unchanged when adding the host galaxy redshift. Finally, I investigate the differences in the interpretation of the light curve properties with and without knowledge of the redshift. When using the SALT2

  9. The Lyα emission from high- z galaxies hosting strong damped Lyα systems

    NASA Astrophysics Data System (ADS)

    Joshi, Ravi; Srianand, Raghunathan; Noterdaeme, Pasquier; Petitjean, Patrick

    2017-02-01

    We study the average Lyα emission associated with high-z strong (log N(H I) ≥ 21) damped Lyα systems (DLAs). We report Lyα luminosities (LLyα) for the full as well as various sub-samples based on N(H I), z, (r - i) colours of QSOs and rest equivalent width of Si IIλ1526 line (i.e. W1526). For the full sample, we find LLyα < 1041(3σ) erg s- 1 with a 2.8σ level detection of Lyα emission in the red part of the DLA trough. The LLyα is found to be higher for systems with higher W1526 with its peak, detected at ≥3σ, redshifted by about 300-400 km s-1 with respect to the systemic absorption redshift, as seen in Lyman break galaxies (LBGs) and Lyα emitters. A clear signature of a double-hump Lyα profile is seen when we consider W1526 ≥0.4 Å and (r - i) < 0.05. Based on the known correlation between metallicity and W1526, we interpret our results in terms of star formation rate (SFR) being higher in high-metallicity (mass) galaxies with high velocity fields that facilitates easy Lyα escape. The measured Lyα surface brightness requires local ionizing radiation that is 4-10 times stronger than the metagalactic UV background at these redshifts. The relationship between the SFR and surface mass density of atomic gas seen in DLAs is similar to that of local dwarf and metal-poor galaxies. We show that the low-luminosity galaxies will contribute appreciably to the stacked spectrum if the size-luminosity relation seen for H I at low z is also present at high-z. Alternatively, large Lyα haloes seen around LBGs could also explain our measurements.

  10. Identifying the Location in the Host Galaxy of Short GRB 1111l7A with the Chandra Sub- Arcsecond Position

    NASA Technical Reports Server (NTRS)

    Sakamoto, Takanori; Troja, E.; Aoki, K.; Guiriec, S.; Im, M.; Leloudas, G.; Malesani, D.; Melandri, A.; deUgartePostigo, A.; Urata, Y.; Xu, D.; DAvanzo, P.; Gorosabel, J.; Anderson, M. I.; Fynbo, J. P. U.; Aoki, K.; Sanchez-Ramirez, R.

    2012-01-01

    We present our successful program using Chandra for identifying the X-ray afterglow with sub-arcsecond accuracy for the short GRB 111117A d iscovered by Swift and Fermi. Thanks to our rapid target of opportuni ty request, Chandra clearly detected the X-ray afterglow, whereas no optical afterglow was found in deep optical observations. Instead, we clearly detect the host galaxy in optica; and also in near-infrared b ands. We found that the best photometric redshift fitofthe host is z = 1.31:(+0.46/-0.23) (90% confidence), making it one of the highest redshift short GRBs. Furthermore, we see an offset of 1.0+/-O.2 arcseco nds, which corresponds to 8.4+/-1.7 kpc aSBuming z= 1.31, between the host and the afterglow position. We discuss the importance of using Chandra for obtaining sub-arcsecond localization of the afterglow in X -rays for short GRBs to study GRB environments in great detail.

  11. The dust, nebular emission, and dependence on QSO radio properties of the associated Mg II absorption line systems

    SciTech Connect

    Khare, Pushpa; Daniel, Vanden Berk; Rahmani, Hadi; York, Donald G.

    2014-10-10

    We studied dust reddening and [O II] emission in 1730 Mg II associated absorption systems (AAS; relative velocity with respect to QSOs, ≤3000 km s{sup –1}; in units of velocity of light, β, ≤0.01) with 0.4 ≤z {sub abs} ≤ 2 in the Sloan Digital Sky Survey DR7, focusing on their dependence on the radio and other QSO properties. We used control samples, several with matching radio properties, to show that (1) AAS in radio-detected (RD) QSOs cause 2.6 ± 0.2 times higher dust extinction than those in radio-undetected (RUD) ones, which in turn cause 2.9 ± 0.7 times the dust extinction in the intervening systems; (2) AAS in core-dominated QSOs cause 2.0 ± 0.1 times higher dust extinction than those in lobe-dominated QSOs; (3) the occurrence of AAS is 2.1 ± 0.2 times more likely in RD QSOs than in RUD QSOs and 1.8 ± 0.1 time more likely in QSOs having black holes with masses larger than 1.23 × 10{sup 9} M {sub ☉} than in those with lower-mass black holes; and (4) there is excess flux in [O II]λ3727 emission in the composite spectra of the AAS samples compared with those of the control samples, which is at the emission redshift. The presence of AAS enhances the O II emission from the active galactic nucleus and/or the host galaxy. This excess is similar for both RD and RUD samples and is 2.5 ± 0.4 times higher in lobe-dominated samples than in core-dominated samples. The excess depends on the black hole mass and Eddington ratio. All these point to the intrinsic nature of the AAS except for the systems with z {sub abs} > z {sub em}, which could be infalling galaxies.

  12. Constraining Stellar Properties of Intervening Damped Lyα and Mg II Absorbing Galaxies toward GRB 050730

    NASA Astrophysics Data System (ADS)

    Minowa, Y.; Okoshi, K.; Kobayashi, N.; Takami, H.

    2012-09-01

    We performed multiband deep imaging of the field around GRB 050730 to identify the host galaxies of intervening absorbers, which consist of a damped Lyα absorption (DLA) system at z abs = 3.564, a sub-DLA system at z abs = 3.022, and strong Mg II absorption systems at z abs = 1.773 and 2.253. Our observations were performed after the gamma-ray burst afterglow had disappeared. Thus, our imaging survey has a higher sensitivity to the host galaxies of the intervening absorbers than the normal imaging surveys in the direction of QSOs, for which the QSO glare tends to hide the foreground galaxies. In this deep imaging survey, we could not detect any unambiguous candidates for the host galaxies of the intervening absorbers. Using the 3σ upper limit of the flux in the optical to mid-infrared observing bands, which corresponds to the UV to optical bands in the rest frame of the intervening absorbers, we constrained the star formation rates and stellar masses of the hosts. We estimated the star formation rates for the intervening absorbers to be <~ 2.5 M ⊙ yr-1 for z > 3 DLAs and <~ 1.0 M ⊙ yr-1 for z ~ 2 Mg II systems. Their stellar masses are estimated to be several times 109 M ⊙ or smaller for all intervening galaxies. These properties are comparable to dwarf galaxies, rather than the massive star-forming galaxies commonly seen in the z > 2 galaxy surveys based on emission-line selection or color selection.

  13. DETAILED RADIO VIEW ON TWO STELLAR EXPLOSIONS AND THEIR HOST GALAXY: XRF 080109/SN 2008D AND SN 2007uy in NGC 2770

    SciTech Connect

    Van der Horst, A. J.; Kouveliotou, C.; Paragi, Z.; Sage, L. J.; Pal, S.; Taylor, G. B.; Granot, J.; Ramirez-Ruiz, E.; Ishwara-Chandra, C. H.; Oosterloo, T. A.; Garrett, M. A.; Wiersema, K.; Starling, R. L. C.; Bhattacharya, D.; Curran, P. A.

    2011-01-10

    The galaxy NGC 2770 hosted two core-collapse supernova (SN) explosions, SN 2008D and SN 2007uy, within 10 days of each other and 9 years after the first SN of the same type, SN 1999eh, was found in that galaxy. In particular, SN 2008D attracted a lot of attention due to the detection of an X-ray outburst, which has been hypothesized to be caused by either a (mildly) relativistic jet or the SN shock breakout. We present an extensive study of the radio emission from SN 2008D and SN 2007uy: flux measurements with the Westerbork Synthesis Radio Telescope and the Giant Metrewave Radio Telescope, covering {approx}600 days with observing frequencies ranging from 325 MHz to 8.4 GHz. The results of two epochs of global Very Long Baseline Interferometry observations are also discussed. We have examined the molecular gas in the host galaxy NGC 2770 with the Arizona Radio Observatory 12 m telescope, and present the implications of our observations for the star formation and seemingly high SN rate in this galaxy. Furthermore, we discuss the near-future observing possibilities of the two SNe and their host galaxy at low radio frequencies with the Low Frequency Array.

  14. Bright [C II] 158 μm Emission in a Quasar Host Galaxy at z = 6.54

    NASA Astrophysics Data System (ADS)

    Bañados, E.; Decarli, R.; Walter, F.; Venemans, B. P.; Farina, E. P.; Fan, X.

    2015-05-01

    The [C ii] 158 μm fine-structure line is known to trace regions of active star formation and is the main coolant of the cold, neutral atomic medium. In this Letter, we report a strong detection of the [C ii] line in the host galaxy of the brightest quasar known at z\\gt 6.5, the Pan-STARRS1 selected quasar PSO J036.5078+03.0498 (hereafter P036+03), using the IRAM NOEMA millimeter interferometer. Its [C ii] and total far-infrared luminosities are (5.8+/- 0.7)× {{10}9} {{L}⊙ } and (7.6+/- 1.5)× {{10}12} {{L}⊙ }, respectively. This results in an {{L}[C II]}/{{L}TIR} ratio of ˜ 0.8× {{10}-3}, which is at the high end of those found for active galaxies, though it is lower than the average found in typical main-sequence galaxies at z˜ 0. We also report a tentative additional line that we identify as a blended emission from the {{3}22}-{{3}13} and {{5}23}-{{4}32} H2O transitions. If confirmed, this would be the most distant detection of water emission to date. P036+03 rivals the current prototypical luminous J1148+5251 quasar at z = 6.42, in both rest-frame UV and [C ii] luminosities. Given its brightness and because it is visible from both hemispheres (unlike J1148+5251), P036+03 has the potential of becoming an important laboratory for the study of star formation and of the interstellar medium only ˜800 Myr after the Big Bang. Based on observations carried out under project number E14AG with the IRAM NOEMA Interferometer. IRAM is supported by INSU/CNRS (France), MPG (Germany), and IGN (Spain).

  15. Structural Transition in the NGC 6251 Jet: an Interplay with the Supermassive Black Hole and Its Host Galaxy

    NASA Astrophysics Data System (ADS)

    Tseng, Chih-Yin; Asada, Keiichi; Nakamura, Masanori; Pu, Hung-Yi; Algaba, Juan-Carlos; Lo, Wen-Ping

    2016-12-01

    The structure of the NGC 6251 jet on the milliarcsecond scale is investigated using images taken with the European VLBI Network and the Very Long Baseline Array. We detect a structural transition of the jet from a parabolic to a conical shape at a distance of (1-2) × 105 times the Schwarzschild radius from the central engine, which is close to the sphere of gravitational influence of the supermassive black hole (SMBH). We also examine the jet pressure profiles with the synchrotron minimum energy assumption to discuss the physical origin of the structural transition. The NGC 6251 jet, together with the M87 jet, suggests a fundamental process of structural transition in the jets of active galactic nuclei (AGNs). Collimated AGN jets are characterized by their external galactic medium, showing that AGN jets interplay with the SMBH and its host galaxy.

  16. Reaching the peak of the quasar spectral energy distribution - II. Exploring the accretion disc, dusty torus and host galaxy

    NASA Astrophysics Data System (ADS)

    Collinson, James S.; Ward, Martin J.; Landt, Hermine; Done, Chris; Elvis, Martin; McDowell, Jonathan C.

    2017-02-01

    We continue our study of the spectral energy distributions (SEDs) of 11 active galactic nuclei (AGN) at 1.5 < z < 2.2, with optical-near-infrared (NIR) spectra, X-ray data and mid-IR photometry. In a previous paper, we presented the observations and models; in this paper, we explore the parameter space of these models. We first quantify uncertainties on the black hole (BH) masses (MBH) and degeneracies between SED parameters. The effect of BH spin is tested, and we find that while low-to-moderate spin values (a* ≤ 0.9) are compatible with the data in all cases, maximal spin (a* = 0.998) can only describe the data if the accretion disc is face-on. The outer accretion disc radii are well constrained in 8/11 objects and are found to be a factor ˜5 smaller than the self-gravity radii. We then extend our modelling campaign into the mid-IR regime with Wide-field Infrared Survey Explorer photometry, adding components for the host galaxy and dusty torus. Our estimates of the host galaxy luminosities are consistent with the MBH-bulge relationship, and the measured torus properties (covering factor and temperature) are in agreement with earlier work, suggesting a predominantly silicate-based grain composition. Finally, we deconvolve the optical-NIR spectra using our SED continuum model. We claim that this is a more physically motivated approach than using empirical descriptions of the continuum such as broken power laws. For our small sample, we verify previously noted correlations between emission linewidths and luminosities commonly used for single-epoch MBH estimates, and observe a statistically significant anticorrelation between [O III] equivalent width and AGN luminosity.

  17. THE RELATION BETWEEN EJECTA VELOCITY, INTRINSIC COLOR, AND HOST-GALAXY MASS FOR HIGH-REDSHIFT TYPE Ia SUPERNOVAE

    SciTech Connect

    Foley, Ryan J.

    2012-04-01

    Recently, using a large low-redshift sample of Type Ia supernovae (SNe Ia), we discovered a relation between SN Ia ejecta velocity and intrinsic color that improves the distance precision of SNe Ia and reduces potential systematic biases related to dust reddening. No SN Ia cosmological results have yet made a correction for the 'velocity-color' relation. To test the existence of such a relation and constrain its properties at high redshift, we examine a sample of 75 SNe Ia discovered and observed by the Sloan Digital Sky Survey-II Supernova Survey and Supernova Legacy Survey. From each spectrum, we measure ejecta velocities at maximum brightness for the Ca H and K and Si II {lambda}6355 features, v{sup 0}{sub CaHandK} and v{sup 0}{sub SiII}, respectively. Using SN light curve parameters, we determine the intrinsic B{sub max} - V{sub max} for each SN. Similar to what was found at low redshift, we find that SNe Ia with higher ejecta velocity tend to be intrinsically redder than SNe Ia with lower ejecta velocity. The distributions of ejecta velocities for SNe Ia at low and high redshift are similar, indicating that current cosmological results should have little bias related to the velocity-color relation. Additionally, we find a slight (2.4{sigma} significant) trend between SN Ia ejecta velocity and host-galaxy mass such that SNe Ia in high-mass host galaxies tend to have lower ejecta velocities as probed by v{sup 0}{sub CaHandK}. These results emphasize the importance of spectroscopy for SN Ia cosmology.

  18. DETERMINING TYPE Ia SUPERNOVA HOST GALAXY EXTINCTION PROBABILITIES AND A STATISTICAL APPROACH TO ESTIMATING THE ABSORPTION-TO-REDDENING RATIO R{sub V}

    SciTech Connect

    Cikota, Aleksandar; Deustua, Susana; Marleau, Francine

    2016-03-10

    We investigate limits on the extinction values of Type Ia supernovae (SNe Ia) to statistically determine the most probable color excess, E(B – V), with galactocentric distance, and use these statistics to determine the absorption-to-reddening ratio, R{sub V}, for dust in the host galaxies. We determined pixel-based dust mass surface density maps for 59 galaxies from the Key Insight on Nearby Galaxies: a Far-infrared Survey with Herschel (KINGFISH). We use SN Ia spectral templates to develop a Monte Carlo simulation of color excess E(B – V) with R{sub V} = 3.1 and investigate the color excess probabilities E(B – V) with projected radial galaxy center distance. Additionally, we tested our model using observed spectra of SN 1989B, SN 2002bo, and SN 2006X, which occurred in three KINGFISH galaxies. Finally, we determined the most probable reddening for Sa–Sap, Sab–Sbp, Sbc–Scp, Scd–Sdm, S0, and irregular galaxy classes as a function of R/R{sub 25}. We find that the largest expected reddening probabilities are in Sab–Sb and Sbc–Sc galaxies, while S0 and irregular galaxies are very dust poor. We present a new approach for determining the absorption-to-reddening ratio R{sub V} using color excess probability functions and find values of R{sub V} = 2.71 ± 1.58 for 21 SNe Ia observed in Sab–Sbp galaxies, and R{sub V} = 1.70 ± 0.38, for 34 SNe Ia observed in Sbc–Scp galaxies.

  19. Determining Type Ia Supernova Host Galaxy Extinction Probabilities and a Statistical Approach to Estimating the Absorption-to-reddening Ratio RV

    NASA Astrophysics Data System (ADS)

    Cikota, Aleksandar; Deustua, Susana; Marleau, Francine

    2016-03-01

    We investigate limits on the extinction values of Type Ia supernovae (SNe Ia) to statistically determine the most probable color excess, E(B - V), with galactocentric distance, and use these statistics to determine the absorption-to-reddening ratio, RV, for dust in the host galaxies. We determined pixel-based dust mass surface density maps for 59 galaxies from the Key Insight on Nearby Galaxies: a Far-infrared Survey with Herschel (KINGFISH). We use SN Ia spectral templates to develop a Monte Carlo simulation of color excess E(B - V) with RV = 3.1 and investigate the color excess probabilities E(B - V) with projected radial galaxy center distance. Additionally, we tested our model using observed spectra of SN 1989B, SN 2002bo, and SN 2006X, which occurred in three KINGFISH galaxies. Finally, we determined the most probable reddening for Sa-Sap, Sab-Sbp, Sbc-Scp, Scd-Sdm, S0, and irregular galaxy classes as a function of R/R25. We find that the largest expected reddening probabilities are in Sab-Sb and Sbc-Sc galaxies, while S0 and irregular galaxies are very dust poor. We present a new approach for determining the absorption-to-reddening ratio RV using color excess probability functions and find values of RV = 2.71 ± 1.58 for 21 SNe Ia observed in Sab-Sbp galaxies, and RV = 1.70 ± 0.38, for 34 SNe Ia observed in Sbc-Scp galaxies.

  20. A revised host galaxy association for GRB 020819B: a high-redshift dusty starburst, not a low-redshift gas-poor spiral

    NASA Astrophysics Data System (ADS)

    Perley, Daniel A.; Krühler, Thomas; Schady, Patricia; Michałowski, Michał J.; Thöne, Christina C.; Petry, Dirk; Graham, John F.; Greiner, Jochen; Klose, Sylvio; Schulze, Steve; Kim, Sam

    2017-02-01

    The purported spiral host galaxy of GRB 020819B at z = 0.41 has been seminal in establishing our view of the diversity of long-duration gamma-ray burst environments: Optical spectroscopy of this host provided evidence that gamma-ray bursts (GRBs) can form even at high metallicities, whereas millimetric observations suggested that GRBs may preferentially form in regions with minimal molecular gas. We report new observations from the Very Large Telescope (Multi Unit Spectroscopic Explorer and X-shooter), which demonstrate that the purported host is an unrelated foreground galaxy. The probable radio afterglow is coincident with a compact, highly star forming, dusty galaxy at z = 1.9621. The revised redshift naturally explains the apparent non-detection of CO(3-2) line emission at the afterglow site from the Atacama Large Millimetre Observatory. There is no evidence that molecular gas properties in GRB host galaxies are unusual, and limited evidence that GRBs can form readily at a super-Solar metallicity.

  1. Late-time VLA reobservations rule out ULIRG-like host galaxies for most pre- Swift long-duration gamma-ray bursts

    NASA Astrophysics Data System (ADS)

    Perley, Daniel A.; Hjorth, Jens; Tanvir, Nial R.; Perley, Richard A.

    2017-02-01

    We present new Jansky Very Large Array observations of five pre-Swift gamma-ray bursts for which an ultraluminous [star formation rate (SFR) >100 M⊙ yr-1] dusty host galaxy had previously been inferred from radio or submillimetre observations taken within a few years after the burst. In four of the five cases, we no longer detect any source at the host location to limits much fainter than the original observations, ruling out the existence of an ultraluminous galaxy hosting any of these gamma-ray bursts (GRBs). We continue to detect a source at the position of GRB 980703, but it is much fainter than it was a decade ago and the inferred radio SFR (∼80 M⊙) is relatively modest. The radio flattening at 200-1000 d observed in the light curve of this GRB may have been caused by a decelerating counterjet oriented 180 deg away from the viewer, although an unjetted wind model can also explain the data. Our results eliminate all well-established ultraluminous infrared galaxies (ULIRGs) among the pre-Swift host population. They also rule out all cases for which an unobscured GRB was found in a galaxy dominated by heavily obscured star formation. When GRBs do occur in ULIRGs, the afterglow is almost always observed to be heavily obscured, consistent with the large dust opacities and high dust covering fractions characteristic of these systems.

  2. TYPE Ia SUPERNOVA PROPERTIES AS A FUNCTION OF THE DISTANCE TO THE HOST GALAXY IN THE SDSS-II SN SURVEY

    SciTech Connect

    Galbany, Lluis; Miquel, Ramon; Oestman, Linda; Brown, Peter J.; Olmstead, Matthew D.; Cinabro, David; D'Andrea, Chris B.; Nichol, Robert C.; Frieman, Joshua; Jha, Saurabh W.; Marriner, John; Nordin, Jakob; Sako, Masao; Schneider, Donald P.; Smith, Mathew; Sollerman, Jesper; Pan, Kaike; Snedden, Stephanie; Bizyaev, Dmitry; Brewington, Howard; and others

    2012-08-20

    We use Type Ia supernovae (SNe Ia) discovered by the Sloan Digital Sky Survey-II SN Survey to search for dependencies between SN Ia properties and the projected distance to the host-galaxy center, using the distance as a proxy for local galaxy properties (local star formation rate, local metallicity, etc.). The sample consists of almost 200 spectroscopically or photometrically confirmed SNe Ia at redshifts below 0.25. The sample is split into two groups depending on the morphology of the host galaxy. We fit light curves using both MLCS2K2 and SALT2, and determine color (A{sub V} , c) and light-curve shape ({Delta}, x{sub 1}) parameters for each SN Ia, as well as its residual in the Hubble diagram. We then correlate these parameters with both the physical and the normalized distances to the center of the host galaxy and look for trends in the mean values and scatters of these parameters with increasing distance. The most significant (at the 4{sigma} level) finding is that the average fitted A{sub V} from MLCS2K2 and c from SALT2 decrease with the projected distance for SNe Ia in spiral galaxies. We also find indications that supernovae (SNe) in elliptical galaxies tend to have narrower light curves if they explode at larger distances, although this may be due to selection effects in our sample. We do not find strong correlations between the residuals of the distance moduli with respect to the Hubble flow and the galactocentric distances, which indicates a limited correlation between SN magnitudes after standardization and local host metallicity.

  3. Type Ia Supernova Properties as a Function of the Distance to the Host Galaxy in the SDSS-II SN Survey

    SciTech Connect

    Galbany, Lluis; et al.

    2012-08-20

    We use type-Ia supernovae (SNe Ia) discovered by the SDSS-II SN Survey to search for dependencies between SN Ia properties and the projected distance to the host galaxy center, using the distance as a proxy for local galaxy properties (local star-formation rate, local metallicity, etc.). The sample consists of almost 200 spectroscopically or photometrically confirmed SNe Ia at redshifts below 0.25. The sample is split into two groups depending on the morphology of the host galaxy. We fit light-curves using both MLCS2k2 and SALT2, and determine color (AV, c) and light-curve shape (delta, x1) parameters for each SN Ia, as well as its residual in the Hubble diagram. We then correlate these parameters with both the physical and the normalized distances to the center of the host galaxy and look for trends in the mean values and scatters of these parameters with increasing distance. The most significant (at the 4-sigma level) finding is that the average fitted AV from MLCS2k2 and c from SALT2 decrease with the projected distance for SNe Ia in spiral galaxies. We also find indications that SNe in elliptical galaxies tend to have narrower light-curves if they explode at larger distances, although this may be due to selection effects in our sample. We do not find strong correlations between the residuals of the distance moduli with respect to the Hubble flow and the galactocentric distances, which indicates a limited correlation between SN magnitudes after standardization and local host metallicity.

  4. ALMA resolves extended star formation in high-z AGN host galaxies

    NASA Astrophysics Data System (ADS)

    Harrison, C. M.; Simpson, J. M.; Stanley, F.; Alexander, D. M.; Daddi, E.; Mullaney, J. R.; Pannella, M.; Rosario, D. J.; Smail, Ian

    2016-03-01

    We present high-resolution (0.3 arcsec) Atacama Large Millimeter Array (ALMA) 870 μm imaging of five z ≈ 1.5-4.5 X-ray detected AGN (with luminosities of L2-8keV > 1042 erg s-1). These data provide a ≳20 times improvement in spatial resolution over single-dish rest-frame far-infrared (FIR) measurements. The sub-millimetre emission is extended on scales of FWHM ≈ 0.2 arcsec-0.5 arcsec, corresponding to physical sizes of 1-3 kpc (median value of 1.8 kpc). These sizes are comparable to the majority of z=1-5 sub-millimetre galaxies (SMGs) with equivalent ALMA measurements. In combination with spectral energy distribution analyses, we attribute this rest-frame FIR emission to dust heated by star formation. The implied star-formation rate surface densities are ≈20-200 M⊙ yr-1 kpc-2, which are consistent with SMGs of comparable FIR luminosities (i.e. LIR ≈ [1-5] × 1012 L⊙). Although limited by a small sample of AGN, which all have high-FIR luminosities, our study suggests that the kpc-scale spatial distribution and surface density of star formation in high-redshift star-forming galaxies is the same irrespective of the presence of X-ray detected AGN.

  5. A New NIR Flareof the QSO PMNJ2301-0157

    NASA Astrophysics Data System (ADS)

    Carrasco, L.; Miramon, J.; Recillas, E.; Porras, A.; Chavushyan, V.; Mayya, D. Y.

    2016-12-01

    We report on the new NIR flare of the high redshift QSO PMNJ2301-0157 (z=0.778), cross identified with the source BZQJ 2301-1058. On November 13th,2016 (MJD 2457705.722), we found the source with the following flux in the NIR band: H = 14.287 +/- 0.03.

  6. NIR flare of the QSO PMNJ2301-0157

    NASA Astrophysics Data System (ADS)

    Carrasco, L.; Miramon, J.; Porras, A.; Recillas, E.; Chavushyan, V.; Carraminana, A.

    2015-10-01

    We report on the recent NIR flare of the high redshift QSO PMNJ2301-0157 (z=0.778), cross identified with the source BZQJ 2301-1058. On September 25th,2015 (MJD 2457290.775), we found the source with the following flux in the NIR band: H = 14.954 +/- 0.07.

  7. CO-EVOLUTION OF SUPERMASSIVE BLACK HOLE AND HOST GALAXY FROM z {approx} 1 TO z = 0

    SciTech Connect

    Kiuchi, Gaku; Ohta, Kouji; Akiyama, Masayuki

    2009-05-01

    Stellar masses of bulges in hosts of active galactic nuclei (AGNs) and black hole masses in the AGNs are derived at z = 0.5-1.15 to study evolution of the black hole-to-bulge mass relation. In order to derive bulge stellar masses, we use a sample of type-2 AGNs to avoid the bright nuclear light. 34 type-2 AGNs are selected from the spectroscopically identified X-ray sources in the Chandra Deep Field South. We use optical images from the Hubble Space Telescope, and near- and mid-infrared photometry from the Very Large Telescope and the Spitzer Space Telescope. The bulge components are derived by fitting the two-dimensional surface brightness model consisting of a bulge and a disk component to the optical images. We derive stellar masses (M {sub bulge}) and star formation rates (SFRs) of the bulge components by spectral energy distribution fitting. The derived M {sub bulge} ranges over 10{sup 9}-10{sup 11} M {sub sun}, and the estimated SFR is 0.01-100 M {sub sun} yr{sup -1}. Masses of supermassive black holes (SMBHs; M {sub .}) and black hole accretion rates (BHARs) are estimated with the absorption-corrected X-ray luminosities in the 2-10 keV band under an assumption of the constant Eddington ratio of 0.1 and the constant energy conversion factor of 0.1. Resulting black hole masses and BHARs range over 10{sup 5.5}-10{sup 8} M {sub sun} and 0.001-1 M {sub sun} yr{sup -1}, respectively. For luminous AGNs, the estimated M {sub .}/M {sub bulge} ratio is {approx}4 x 10{sup -4} in the median, which is lower than that for local galaxies and for type-2 AGNs at z {approx} 0.2. However, these differences are within uncertainty and are not significant. This can imply that SMBHs and their host galaxies are evolving almost holding the constant M {sub .}/M {sub bulge} ratio from z {approx} 1.0 to 0 in a cosmological timescale. Meanwhile, the estimated BHAR/SFR ratio is about 60 times larger than the M {sub .}/M {sub bulge} ratio in the median value. This indicates that growths

  8. RESOLVING THE DYNAMICAL MASS OF A z {approx} 1.3 QUASI-STELLAR OBJECT HOST GALAXY USING SINFONI AND LASER GUIDE STAR ASSISTED ADAPTIVE OPTICS

    SciTech Connect

    Inskip, K. J.; Jahnke, K.; Rix, H.-W.; Van de Ven, G.

    2011-10-01

    Recent studies of the tight scaling relations between the masses of supermassive black holes (BHs) and their host galaxies have suggested that in the past BHs constituted a larger fraction of their host galaxies' mass. However, these arguments are limited by selection effects and difficulties in determining robust host galaxy masses at high redshifts. Here we report the first results of a new, complementary diagnostic route: we directly determine a dynamical host galaxy mass for the z = 1.3 luminous quasar J090543.56+043347.3 through high spatial resolution (0.''47, 4 kpc FWHM) observations of the host galaxy gas kinematics over 30 x 40 kpc using the European Southern Observatory/Very Large Telescope/SINFONI with laser guide star adaptive optics. Combining our result of M{sub dyn} = 2.05{sup +1.68}{sub -0.74} x 10{sup 11} M{sub sun} (within a radius 5.25 {+-} 1.05 kpc) with M{sub BH,MgII} = 9.02 {+-} 1.43 x 10{sup 8} M{sub sun}, M{sub BH,H{alpha}} = 2.83{sup +1.93}{sub -1.13} x 10{sup 8} M{sub sun}, we find that the ratio of BH mass to host galaxy dynamical mass for J090543.56+043347.3 matches the present-day relation for M{sub BH} versus M{sub Bulge,Dyn}, well within the IR scatter, and deviating at most by a factor of two from the mean. J090543.56+043347.3 displays clear signs of an ongoing tidal interaction and of spatially extended star formation at a rate of 50-100 M{sub sun} yr{sup -1}, above the cosmic average for a galaxy of this mass and redshift. We argue that its subsequent evolution may move J090543.56+043347.3 even closer to the z = 0 relation for M{sub BH} versus M{sub Bulge,Dyn}. Our results support the picture in which any substantive evolution in these relations must occur prior to z {approx} 1.3. Having demonstrated the power of this modeling approach, we are currently analyzing similar data on seven further objects to better constrain such evolution.

  9. VizieR Online Data Catalog: Host galaxies of Type Ia SN from PTF (Pan+, 2014)

    NASA Astrophysics Data System (ADS)

    Pan, Y.-C.; Sullivan, M.; Maguire, K.; Hook, I. M.; Nugent, P. E.; Howell, D. A.; Arcavi, I.; Botyanszki, J.; Cenko, S. B.; Derose, J.; Fakhouri, H. K.; Gal-Yam, A.; Hsiao, E.; Kulkarni, S. R.; Laher, R. R.; Lidman, C.; Nordin, J.; Walker, E. S.; Xu, D.

    2014-11-01

    The SNe Ia studied in this paper were discovered by the PTF, a project which operated from 2009 to 2012 and used the CFH12k wide-field survey camera mounted on the Samuel Oschin 48 inch telescope (P48) at the Palomar Observatory. The observational cadences used to discover the SNe ranged from hours up to ~5d. SN candidates were identified in image subtraction data and ranked using both simple cuts on the detection parameters and a machine learning algorithm (Bloom et al. 2012PASP..124.1175B), and then visually confirmed by members of the PTF collaboration or, from mid-2010 onwards, via the citizen science project 'Galaxy Zoo: Supernova' (Smith et al., 2011MNRAS.412.1309S). The latter identified eight of the SNe studied in this paper. (4 data files).

  10. Galaxy-environment Interactions as Revealed by the Circumgalactic Medium

    NASA Astrophysics Data System (ADS)

    Burchett, Joseph; Tripp, Todd M.; Wang, Daniel; Willmer, Christopher; Prochaska, Jason X.; Werk, Jessica; Bordoloi, Rongmon; Katz, Neal; Tumlinson, Jason

    2017-01-01

    Galaxies do not live in isolation, and their star formation activity and gas supply are closely tied to the density of the environment in which they reside. The circumgalactic medium (CGM) serves as the point of first contact between a galaxy and its environment and mediates the gas accretion and outflow processes that regulate the galaxy ecosystem. Employing a combination of ultraviolet QSO spectroscopy, optical galaxy surveys, and X-ray imaging and spectroscopy, I will show that the metal-enriched gas and cool, photoionized H I in the CGM gas reflect the galaxy’s large-scale environment from scales of modest groups to clusters. Thus, QSO absorption line spectroscopy provides uniquely sensitive multiphase gas diagnostics of the physical conditions at the sites of galaxy-environment interactions. By shock-heating or stripping the CGM gas, as is indicated by its absorption, these interactions may deplete or deprive the galaxy's gas supply and quench its star formation.

  11. ALMA DETECTION OF THE VIBRATIONALLY EXCITED HCN J = 4-3 EMISSION LINE IN THE AGN-HOSTING LUMINOUS INFRARED GALAXY IRAS 20551–4250

    SciTech Connect

    Imanishi, Masatoshi; Nakanishi, Kouichiro

    2013-10-01

    We present results from our ALMA Cycle 0 observations, at the frequencies around the HCN, HCO{sup +}, and HNC J = 4-3 transition lines, of the luminous infrared galaxy IRAS 20551–4250 at z = 0.043, which is known to host an energetically important obscured active galactic nucleus (AGN). In addition to the targeted HCN, HCO{sup +}, and HNC J = 4-3 emission lines, two additional strong emission lines are seen, which we attribute to H{sub 2}S and CH{sub 3}CN(+CCH). The HCN-to-HCO{sup +} J = 4-3 flux ratio (∼0.7) is higher than in the other starburst-dominated galaxy (∼0.2) observed in our ALMA Cycle 0 program. We tentatively (∼5σ) detected the vibrationally excited (v {sub 2} = 1) HCN J = 4-3 (l = 1f) emission line, which is important for testing an infrared radiative pumping scenario for HCN. This is the second detection of this molecular transition in external galaxies. The most likely reason for this detection is not only the high flux of this emission line, but also the small molecular line widths observed in this galaxy, suggesting that vibrational excitation of HCN may be relatively common in AGN-hosting galaxies.

  12. The Afterglow, Energetics, and Host Galaxy of the Short-Hard Gamma-Ray Burst 051221a

    NASA Astrophysics Data System (ADS)

    Soderberg, A. M.; Berger, E.; Kasliwal, M.; Frail, D. A.; Price, P. A.; Schmidt, B. P.; Kulkarni, S. R.; Fox, D. B.; Cenko, S. B.; Gal-Yam, A.; Nakar, E.; Roth, K. C.

    2006-10-01

    We present detailed optical, X-ray, and radio observations of the bright afterglow of the short gamma-ray burst 051221a obtained with Gemini, Swift XRT, and the Very Large Array, as well as optical spectra from which we measure the redshift of the burst, z=0.5464. At this redshift the isotropic-equivalent prompt energy release was about 1.5×1051 ergs, and using a standard afterglow synchrotron model, we find that the blast wave kinetic energy is similar, EK,iso~8.4×1051 ergs. An observed jet break at t~5 days indicates that the opening angle is θj~7deg and the total beaming-corrected energy is therefore ~2.5×1049 ergs, comparable to the values inferred for previous short GRBs. We further show that the burst experienced an episode of energy injection by a factor of 3.4 between t=1.4 and 3.4 hr, which was accompanied by reverse shock emission in the radio band. This result provides continued evidence that the central engines of short GRBs may be active significantly longer than the duration of the burst and/or produce a wide range of Lorentz factors. Finally, we show that the host galaxy is actively forming stars at a rate of about 1.6 Msolar yr-1, yet exhibits evidence for an appreciable population of old stars (~1 Gyr) and near-solar metallicity. These properties are intermediate between those of long GRB hosts and previous short burst hosts. The lack of bright supernova emission and the low circumburst density (n~10-3 cm-3), however, continue to support the idea that short bursts are not related to massive stellar death. Given that the total energy release is larger than the predicted yield for a neutrino annihilation mechanism, this suggests that magnetohydrodynamic processes may be required to power the burst.

  13. GRB 091127/SN 2009nz and the VLT/X-shooter spectroscopy of its host galaxy: probing the faint end of the mass-metallicity relation

    NASA Astrophysics Data System (ADS)

    Vergani, S. D.; Flores, H.; Covino, S.; Fugazza, D.; Gorosabel, J.; Levan, A. J.; Puech, M.; Salvaterra, R.; Tello, J. C.; de Ugarte Postigo, A.; D'Avanzo, P.; D'Elia, V.; Fernández, M.; Fynbo, J. P. U.; Ghirlanda, G.; Jelínek, M.; Lundgren, A.; Malesani, D.; Palazzi, E.; Piranomonte, S.; Rodrigues, M.; Sánchez-Ramírez, R.; Terrón, V.; Thöne, C. C.; Antonelli, L. A.; Campana, S.; Castro-Tirado, A. J.; Goldoni, P.; Hammer, F.; Hjorth, J.; Jakobsson, P.; Kaper, L.; Melandri, A.; Milvang-Jensen, B.; Sollerman, J.; Tagliaferri, G.; Tanvir, N. R.; Wiersema, K.; Wijers, R. A. M. J.

    2011-11-01

    We perform a detailed study of the gamma-ray burst GRB 091127/SN 2009nz host galaxy at z = 0.490 using the VLT/X-shooter spectrograph in slit and integral-field unit (IFU) mode. From the analysis of the optical and X-ray afterglow data obtained from ground-based telescopes and Swift-XRT, we confirm the presence of a bump associated with SN 2009nz and find evidence of a possible jet break in the afterglow lightcurve. The X-shooter afterglow spectra reveal several emission lines from the underlying host, from which we derive its integrated properties. These properties agree with those of previously studied GRB-SN hosts and, more generally, with those of the long GRB host population. We use the Hubble Space Telescope and ground-based images of the host to determine its stellar mass (M⋆). Our results extend to lower M⋆ values the M-Z plot derived for the sample of long GRB hosts at 0.3 < z < 1.0 adding new information to probe the faint end of the M-Z relation and the shift of the LGRB host M-Z relation from that found from emission-line galaxy surveys. Thanks to the IFU spectroscopy, we can build the two-dimensional (2D) velocity, velocity dispersion, and star formation rate (SFR) maps. They show that the host galaxy has perturbed rotation kinematics with evidence of a SFR enhancement consistent with the afterglow position. Based on observations made with ESO Telescopes at Paranal Observatory under programmes ID 084.A-0260 and 086.A-0874.

  14. Galaxy Clustering Around Nearby Luminous Quasars

    NASA Technical Reports Server (NTRS)

    Fisher, Karl B.; Bahcall, John N.; Kirhakos, Sofia; Schneider, Donald P.

    1996-01-01

    We examine the clustering of galaxies around a sample of 20 luminous low redshift (z approx. less than 0.30) quasars observed with the Wide Field Camera-2 on the Hubble Space Telescope (HST). The HST resolution makes possible galaxy identification brighter than V = 24.5 and as close as 1 min or 2 min to the quasar. We find a significant enhancement of galaxies within a projected separation of approx. less than 100 1/h kpc of the quasars. If we model the QSO/galaxy correlation function as a power law with a slope given by the galaxy/galaxy correlation function, we find that the ratio of the QSO/galaxy to galaxy/galaxy correlation functions is 3.8 +/- 0.8. The galaxy counts within r less than 15 1/h kpc of the quasars are too high for the density profile to have an appreciable core radius (approx. greater than 100 1/h kpc). Our results reinforce the idea that low redshift quasars are located preferentially in groups of 10-20 galaxies rather than in rich clusters. We see no significant difference in the clustering amplitudes derived from radio-loud and radio-quiet subsamples.

  15. Black hole growth and starburst activity at z = 0.6-4 in the Chandra Deep Field South. Host galaxies properties of obscured AGN

    NASA Astrophysics Data System (ADS)

    Brusa, M.; Fiore, F.; Santini, P.; Grazian, A.; Comastri, A.; Zamorani, G.; Hasinger, G.; Merloni, A.; Civano, F.; Fontana, A.; Mainieri, V.

    2009-12-01

    Aims: The co-evolution of host galaxies and the active black holes which reside in their centre is one of the most important topics in modern observational cosmology. Here we present a study of the properties of obscured active galactic nuclei (AGN) detected in the CDFS 1 Ms observation and their host galaxies. Methods: We limited the analysis to the MUSIC area, for which deep K-band observations obtained with ISAAC@VLT are available, ensuring accurate identifications of the counterparts of the X-ray sources as well as reliable determination of photometric redshifts and galaxy parameters, such as stellar masses and star formation rates. In particular, we: 1) refined the X-ray/infrared/optical association of 179 sources in the MUSIC area detected in the Chandra observation; 2) studied the host galaxies observed and rest frame colors and properties. Results: We found that X-ray selected (LX ⪆ 1042 erg s-1) AGN show Spitzer colors consistent with both AGN and starburst dominated infrared continuum; the latter would not have been selected as AGN from infrared diagnostics. The host galaxies of X-ray selected obscured AGN are all massive (Mast > 1010 M_⊙) and, in 50% of the cases, are also actively forming stars (1/SSFR < tHubble) in dusty environments. The median L/LEdd value of the active nucleus is between 2% and 10% depending on the assumed MBH/Mast ratio. Finally, we found that the X-ray selected AGN fraction increases with the stellar mass up to a value of 30% at z > 1 and Mast > 3 × 1011 M_⊙, a fraction significantly higher than in the local Universe for AGN of similar luminosities. Tables [see full textsee full textsee full text] and [see full textsee full textsee full text] are only available in electronic form at http://www.aanda.org

  16. Galaxy Clusters in the Line of Sight to Background Quasars. III. Multi-object Spectroscopy

    NASA Astrophysics Data System (ADS)

    Andrews, H.; Barrientos, L. F.; López, S.; Lira, P.; Padilla, N.; Gilbank, D. G.; Lacerna, I.; Maureira, M. J.; Ellingson, E.; Gladders, M. D.; Yee, H. K. C.

    2013-09-01

    We present Gemini/GMOS-S multi-object spectroscopy of 31 galaxy cluster candidates at redshifts between 0.2 and 1.0 and centered on QSO sight lines taken from López et al. The targets were selected based on the presence of an intervening Mg II absorption system at a similar redshift to that of a galaxy cluster candidate lying at a projected distance <2 h_{71}^{-1} Mpc from the QSO sight line (a "photometric hit"). The absorption systems span rest-frame equivalent widths between 0.015 and 2.028 Å. Our aim was three-fold: (1) to identify the absorbing galaxies and determine their impact parameters, (2) to confirm the galaxy cluster candidates in the vicinity of each quasar sightline, and (3) to determine whether the absorbing galaxies reside in galaxy clusters. In this way, we are able to characterize the absorption systems associated with cluster members. Our main findings are as follows. (1) We identified 10 out of 24 absorbing galaxies with redshifts between 0.2509 <= z gal <= 1.0955, up to an impact parameter of 142\\ h_{71}^{-1} kpc and a maximum velocity difference of 280 km s-1. (2) We spectroscopically confirmed 20 out of 31 cluster/group candidates, with most of the confirmed clusters/groups at z < 0.7. This relatively low efficiency results from the fact that we centered our observations on the QSO location, and thus occasionally some of the cluster centers were outside the instrument field of view. (3) Following from the results above, we spectroscopically confirmed of 10 out of 14 photometric hits within ~650 km s-1 from galaxy clusters/groups, in addition to two new ones related to galaxy group environments. These numbers imply efficiencies of 71% in finding such systems with MOS spectroscopy. This is a remarkable result since we defined a photometric hit as those cluster-absorber pairs having a redshift difference Δz = 0.1. The general population of our confirmed absorbing galaxies have luminosities L_{B} \\sim L_{B}^{\\ast } and mean rest

  17. The Damped Lyalpha Absorber Toward the Double QSO HE 1104-1805

    NASA Astrophysics Data System (ADS)

    Roth, K. C.; Songaila, A.; Jim, K. T. C.

    1998-05-01

    We recently obtained two hours of Keck HIRES data for the gravitational lens candidate HE 1104-1805A,B (z_QSO=2.303). We observed with a fixed position angle so that both quasar images (separation ~ 3'') fell on the slit simultaneously. The resulting high-resolution spectra (FWHM = 8 km/s) have a signal-to-noise ratio of 30 for the brighter component (A) while the fainter B component has S/N ~ 10 at 6000 Angstroms. Lower resolution spectra had previously revealed the presence of a damped Lyalpha absorber (z_damped=1.665) toward A which was absent in the spectrum of B (Wisotzki et al. 1993). Our spectra cover numerous weak low-ionization lines including Fe II, Zn II, Cr II, Ni II and Ti II which we use for abundance and dust depletion analyses. There also is a metal-line system at lower redshift (z_metal=1.321) which does cover both lines of sight, although the velocity profiles of the Fe II lines are significantly different. To complement the spectral data and verify the nature of the damped and metal-line absorbers, we have imaged the system with the UH 2.2m Tip-Tilt system and QUIRC infrared array. Our images have excellent image quality (FWHM = 0.3'') and cover ~ 1.5' centered on the QSO. This corresponds to a diameter of ~ 750 kpc at the absorption redshift of the damped Lyalpha system (Omega =0.3, H_deg=65 km s(-1) Mpc(-1) ). A 10 kpc galactic disk at this redshift would have an angular extent of 1.2''. This data was obtained as part of an ongoing program designed to relate the absorption characteristics of damped Lyalpha absorbers to the ISM of nearby galaxies and image the intervening systems responsible (see Jim & Roth, Bauer et al., & Kolhatkar et al. also presenting at this session).

  18. Dark and luminous matter in galaxies and large scale structure

    NASA Astrophysics Data System (ADS)

    Jiang, Guangfei

    In this dissertation, I investigate the transverse proximity effect in Lyalpha transmitted flux, the baryon fraction and stellar mass-to-light ratio in early-type galaxies, and the relation between dark matter halos and optical observables of galaxy clusters. The proximity effect is the observed reduction in absorption by HI in the Lyalpha forest in the proximity of QSOs. This effect was explained as the excess ionization from QSO and used to investigate the background QSO emission intensity. However, in some of the observations, there is only very weak or no proximity effect observed at all. This might arise from the QSOs residing in higher density regions. In this chapter, I investigate the effect of enhanced density close to QSOs with synthetic spectra from smoothed particle hydrodynamics (SPH) simulations at redshifts z = 2, z = 3, and z = 4. By modeling the halo mass-QSO luminosity relationship, we compare the expected effect from the enhanced density and that from excess QSO photoionization. The influence of the QSO flux increases with redshifts, with more absorptions around low mass halos and much higher transmitted flux close to high mass halos. To investigate the baryon fraction and the evolution of the stellar mass-to-light ratio in early-type galaxies, the joint gravitational lensing and stellar dynamical analysis of fifteen massive field early-type galaxies are used. The following numerical results are found: (i) A joint-likelihood gives an average logarithmic density slope for the total mass density of = 2.01+0.02-0.03 (68% C.L.; rhotot ∝ r-gamma' ) inside = 4.2 +/- 0.4 kpc (rms of 1.6 kpc). The inferred intrinsic rms spread in logarithmic density slopes is sigmagamma' = 0.12, which might still include some minor systematic uncertainties. (ii) The average position-angle difference between the light distribution and the total mass distribution is found to be = 0 +/- 3 degrees (rms of 10 degrees), setting an upper limit

  19. A Tidal Disruption Event in a Nearby Galaxy Hosting an Intermediate Mass Black Hole

    NASA Technical Reports Server (NTRS)

    Donato, D; Cenko, S. B.; Covino, S.; Troja, E.; Pursimo, T.; Cheung, C. C.; Fox, O.; Kutyrev, A.; Campana, S.; Fugazza, D.; Landt, H.; Butler, N. R.

    2014-01-01

    We report the serendipitous discovery of a bright point source flare in the Abell cluster A1795 with archival EUVE and Chandra observations. Assuming the EUVE emission is associated with the Chandra source, the X-ray 0.5-7 kiloelectronvolt flux declined by a factor of approximately 2300 over a time span of 6 years, following a power-law decay with index approximately equal to 2.44 plus or minus 0.40. The Chandra data alone vary by a factor of approximately 20. The spectrum is well fit by a blackbody with a constant temperature of kiloteslas approximately equal to 0.09 kiloelectronvolts (approximately equal to 10 (sup 6) Kelvin). The flare is spatially coincident with the nuclear region of a faint, inactive galaxy with a photometric redshift consistent at the 1 sigma level with the cluster (redshift = 0.062476).We argue that these properties are indicative of a tidal disruption of a star by a black hole (BH) with log(M (sub BH) / M (sub 1 solar mass)) approximately equal to 5.5 plus or minus 0.5. If so, such a discovery indicates that tidal disruption flares may be used to probe BHs in the intermediate mass range, which are very difficult to study by other means.

  20. A tidal disruption event in a nearby galaxy hosting an intermediate mass black hole

    SciTech Connect

    Donato, D.; Troja, E.; Pursimo, T.; Cheung, C. C.; Kutyrev, A.; Landt, H.; Butler, N. R.

    2014-02-01

    We report the serendipitous discovery of a bright point source flare in the Abell cluster A1795 with archival EUVE and Chandra observations. Assuming the EUVE emission is associated with the Chandra source, the X-ray 0.5-7 keV flux declined by a factor of ∼2300 over a time span of 6 yr, following a power-law decay with index ∼2.44 ± 0.40. The Chandra data alone vary by a factor of ∼20. The spectrum is well fit by a blackbody with a constant temperature of kT ∼ 0.09 keV (∼10{sup 6} K). The flare is spatially coincident with the nuclear region of a faint, inactive galaxy with a photometric redshift consistent at the 1σ level with the cluster (z = 0.062476). We argue that these properties are indicative of a tidal disruption of a star by a black hole (BH) with log (M {sub BH}/M {sub ☉}) ∼ 5.5 ± 0.5. If so, such a discovery indicates that tidal disruption flares may be used to probe BHs in the intermediate mass range, which are very difficult to study by other means.

  1. Molecular Gas Kinematics and Star Formation Properties of the Strongly-lensed Quasar Host Galaxy RXS J1131–1231

    NASA Astrophysics Data System (ADS)

    Leung, T. K. Daisy; Riechers, Dominik A.; Pavesi, Riccardo

    2017-02-01

    We report observations of CO(J = 2 → 1) and {CO}(J=3\\to 2) line emission toward the quadruply-lensed quasar RXS J1131‑1231 at z = 0.654 obtained using the Plateau de Bure Interferometer (PdBI) and the Combined Array for Research in Millimeter-wave Astronomy (CARMA). Our lens modeling shows that the asymmetry in the double-horned CO(J = 2 → 1) line profile is mainly a result of differential lensing, where the magnification factor varies from ∼3 to ∼9 across different kinematic components. The intrinsically symmetric line profile and a smooth source-plane velocity gradient suggest that the host galaxy is an extended rotating disk, with a CO size of {R}{CO}∼ 6 kpc and a dynamical mass of {M}{dyn}∼ 8× {10}10 M ⊙. We also find a secondary CO-emitting source near RXS J1131‑1231, the location of which is consistent with the optically-faint companion reported in previous studies. The lensing-corrected molecular gas masses are M gas = (1.4 ± 0.3) × 1010 M ⊙ and (2.0 ± 0.1) × 109 M ⊙ for RXS J1131‑1231 and the companion, respectively. We find a lensing-corrected stellar mass of M * = (3 ± 1) × 1010 M ⊙ and a star formation rate of SFRFIR = (120 ± 63) M ⊙ yr‑1, corresponding to a specific SFR and star formation efficiency comparable to z ∼ 1 disk galaxies not hosting quasars. The implied gas mass fraction of ∼18 ± 4% is consistent with the previously observed cosmic decline since z ∼ 2. We thus find no evidence for quenching of star formation in RXS J1131‑1231. This agrees with our finding of an elevated {M}{BH}/{M}{bulge} ratio of >0.27{}-0.08+0.11% compared to the local value, suggesting that the bulk of its black hole mass is largely in place while its stellar bulge is still assembling.

  2. Active Galactic Nuclei Probed by QSO Absorption Lines

    NASA Astrophysics Data System (ADS)

    Misawa, Toru

    2007-07-01

    Quasars are the extremely bright nuclei found in about 10% of galaxies. A variety of absorption features (known collectively as quasar absorption lines) are detected in the rest-frame UV spectra of these objects. While absorption lines that have very broad widths originate in gas that is probably physocally related to the quasars, narrow absorption lines (NALs) were thought to arise in galaxies and/or in the intter-alacttic medium between the quasars and us. Using high-resolution spectra of quasars, it is found that a substantial fraction of NALs arise in gas in the immediate vicinity of the quasars. A dramatically variable, moderately-broad absorption line in the spectrum of the quasar HS 1603+3820l is also found. The variability of this line is monitored in a campaign with Subaru telescope. These observational results are compared to models for outflows from the quasars, specifically, models for accretion disk winds and evaporating obscuring tori. It is quite important to determine the mechanism of outflow because of its cosmological implications. The outflow could expel angular momentum from the accretion disk and enable quasars to accrete and shine. In addition, the outflow may also regulate star formation in the early stages of the assembly of the host galaxy and enrich the interstellar and intergalactic medium with metals.

  3. HOST GALAXIES OF LUMINOUS TYPE 2 QUASARS AT z {approx} 0.5

    SciTech Connect

    Liu Xin; Greene, Jenny E.; Strauss, Michael A.; Zakamska, Nadia L.; Krolik, Julian H.; Heckman, Timothy M.

    2009-09-10

    We present deep Gemini GMOS optical spectroscopy of nine luminous quasars at redshifts z {approx} 0.5, drawn from the Sloan Digital Sky Survey type 2 quasar sample. Our targets were selected to have high intrinsic luminosities (M{sub V} < -26 mag) as indicated by the [O III] {lambda}5007 A emission-line luminosity (L[{sub OIII}]). Our sample has a median black hole mass of {approx}10{sup 8.8} M{sub sun} inferred assuming the local M {sub BH}-{sigma}{sub *} relation and a median Eddington ratio of {approx}0.7, using stellar velocity dispersions {sigma}{sub *} measured from the G band. We estimate the contamination of the stellar continuum from scattered quasar light based on the strength of broad H{beta}, and provide an empirical calibration of the contamination as a function of L {sub [OIII]}; the scattered-light fraction is {approx}30% of L{sub 5100} for objects with L {sub [OIII]} = 10{sup 9.5} L{sub sun}. Population synthesis indicates that young poststarburst populations (<0.1 Gyr) are prevalent in luminous type 2 quasars, in addition to a relatively old population (>1 Gyr) which dominates the stellar mass. Broad emission complexes around He II {lambda}4686 A with luminosities up to 10{sup 8.3} L{sub sun} are unambiguously detected in three out of the nine targets, indicative of Wolf-Rayet (WR) populations. Population synthesis shows that {approx}5 Myr poststarburst populations contribute substantially to the luminosities (>50% of L{sub 5100}) of all three objects with WR detections. We find two objects with double cores and four with close companions. Our results may suggest that luminous type 2 quasars trace an early stage of galaxy interaction, perhaps responsible for both the quasar and the starburst activity.

  4. Broad Balmer Absorption Line Variability: Evidence of Gas Transverse Motion in the QSO SDSS J125942.80+121312.6

    NASA Astrophysics Data System (ADS)

    Shi, Xiheng; Zhou, Hongyan; Shu, Xinwen; Zhang, Shaohua; Ji, Tuo; Pan, Xiang; Sun, Luming; Zhao, Wen; Hao, Lei

    2016-03-01

    We report on the discovery of broad Balmer absorption lines variability in the QSO SDSS J125942.80+121312.6, based on the optical and near-infrared spectra taken from the SDSS-I, SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS), and TripleSpec observations over a timescale of 5.8 years in the QSO's rest-frame. The blueshifted absorption profile of Hβ shows a variation of more than 5σ at a high velocity portion (\\gt 3000 {km} {{{s}}}-1) of the trough. We perform a detailed analysis for the physical conditions of the absorber using Balmer lines as well as metastable He i and optical Fe ii absorptions (λ4233 from b4P5/2 level and λ5169 from a6S5/2) at the same velocity. These Fe ii lines are identified in the QSO spectra for the first time. According to the photoionization simulations, we estimate a gas density of n({{H}})≈ {10}9.1 {{cm}}-3 and a column density of {N}{col}({{H}})≈ {10}23 {{cm}}-2 for the BOSS data, but the model fails to predict the variations of ionic column densities between the SDSS and BOSS observations if changes in ionizing flux are assumed. We thus propose transverse motion of the absorbing gas being the cause of the observed broad Balmer absorption line variability. In fact, we find that the changes in covering factors of the absorber can well-reproduce all of the observed variations. The absorber is estimated ∼0.94 pc away from the central engine, which is where the outflow likely experiences deceleration due to the collision with the surrounding medium. This scheme is consistent with the argument that LoBAL QSOs may represent the transition from obscured star-forming galaxies to classic QSOs.

  5. The host galaxies of X-ray selected active galactic nuclei to z = 2.5: Structure, star formation, and their relationships from CANDELS and Herschel/PACS

    NASA Astrophysics Data System (ADS)

    Rosario, D. J.; McIntosh, D. H.; van der Wel, A.; Kartaltepe, J.; Lang, P.; Santini, P.; Wuyts, S.; Lutz, D.; Rafelski, M.; Villforth, C.; Alexander, D. M.; Bauer, F. E.; Bell, E. F.; Berta, S.; Brandt, W. N.; Conselice, C. J.; Dekel, A.; Faber, S. M.; Ferguson, H. C.; Genzel, R.; Grogin, N. A.; Kocevski, D. D.; Koekemoer, A. M.; Koo, D. C.; Lotz, J. M.; Magnelli, B.; Maiolino, R.; Mozena, M.; Mullaney, J. R.; Papovich, C. J.; Popesso, P.; Tacconi, L. J.; Trump, J. R.; Avadhuta, S.; Bassett, R.; Bell, A.; Bernyk, M.; Bournaud, F.; Cassata, P.; Cheung, E.; Croton, D.; Donley, J.; DeGroot, L.; Guedes, J.; Hathi, N.; Herrington, J.; Hilton, M.; Lai, K.; Lani, C.; Martig, M.; McGrath, E.; Mutch, S.; Mortlock, A.; McPartland, C.; O'Leary, E.; Peth, M.; Pillepich, A.; Poole, G.; Snyder, D.; Straughn, A.; Telford, O.; Tonini, C.; Wandro, P.

    2015-01-01

    We study the relationship between the structure and star formation rate (SFR) of X-ray selected low and moderate luminosity active galactic nuclei (AGNs) in the two Chandra Deep Fields, using Hubble Space Telescope imaging from the Cosmic Assembly Near Infrared Extragalactic Legacy Survey (CANDELS) and deep far-infrared maps from the PEP+GOODS-Herschel survey. We derive detailed distributions of structural parameters and FIR luminosities from carefully constructed control samples of galaxies, which we then compare to those of the AGNs. At z ~ 1, AGNs show slightly diskier light profiles than massive inactive (non-AGN) galaxies, as well as modestly higher levels of gross galaxy disturbance (as measured by visual signatures of interactions and clumpy structure). In contrast, at z ~ 2, AGNs show similar levels of galaxy disturbance as inactive galaxies, but display a red central light enhancement, which may arise from a more pronounced bulge in AGN hosts or extinguished nuclear light. We undertake a number of tests of both these alternatives, but our results do not strongly favor one interpretation over the other. The mean SFR and its distribution among AGNs and inactive galaxies are similar at z> 1.5. At z< 1, however, clear and significant enhancements are seen in the SFRs of AGNs with bulge-dominated light profiles. These trends suggest an evolution in the relation between nuclear activity and host properties with redshift, towards a minor role for mergers and interactions at z> 1.5. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Appendices are available in electronic form at http://www.aanda.org

  6. Time Variable Associated Absorption in the QSO UM 675

    NASA Astrophysics Data System (ADS)

    Hamann, F. W.; Barlow, T. A.; Beaver, E. A.; Burbidge, E. M.; Cohen, R. D.; Junkkarinen, V. T.; Lyons, R. W.

    1994-05-01

    We discuss dramatic changes in the z_a ~ z_e absorption system of the z_e = 2.15 QSO UM 675 (Q0150-203). The C IV lambda 1550 and N V lambda 1240 doublets at z_a = 2.1344 strengthened by a factor of ~ 3 between the observations of Sargent, Boksenberg and Steidel (1988, ApJS, 68, 539; measured November 1981) and our earliest measurements (November and December 1990). During this time, C IV in the z_a = 2.0083 system may also have strengthened. The variability of other lines in these systems is unknown. Continued monitoring is in progress. We consider several models of the z_a ~ z_e absorption environment, and conclude that the absorbing clouds are close to the QSO and photoionized by the QSO continuum. The variability timescale (<~2.9 yrs rest) requires gas densities gap 4000 cm(-3) to allow changes in the ionization balance. This minimum density, and the high ionization needed to produce the Ne VIII lambda 774 and O VI lambda 1035 absorptions reported previously (E. M. Burbidge et al., 1993, BAAS, 24, 1135), requires clouds <~200 pc from the QSO. The full range of absorption line ionizations (including C III lambda 977 and N III lambda 989) implies that the clouds are segregated, spanning a factor of gap 10 in distance or gap 100 in density. Across these regions the H I fraction varies from ~ 10(-3) to ~ 10(-6) . The total hydrogen column ranges from a few times 10(18) cm(-2) in the low ionization gas to ~ 10(20) cm(-2) where the Ne VIII lines form. The Lyman continuum is expected to be optically thin throughout, consistent with the measured absence of a Lyman edge. The metal abundances are roughly solar or above. Implications of these results are discussed. This work is supported by NASA grant NAG 5-1630.

  7. Host Galaxies of Luminous Type 2 Quasars at z ~ 0.5

    NASA Astrophysics Data System (ADS)

    Liu, Xin; Zakamska, Nadia L.; Greene, Jenny E.; Strauss, Michael A.; Krolik, Julian H.; Heckman, Timothy M.

    2009-09-01

    We present deep Gemini GMOS optical spectroscopy of nine luminous quasars at redshifts z ~ 0.5, drawn from the Sloan Digital Sky Survey type 2 quasar sample. Our targets were selected to have high intrinsic luminosities (MV < -26 mag) as indicated by the [O III] λ5007 Å emission-line luminosity (L [O III]). Our sample has a median black hole mass of ~108.8 M sun inferred assuming the local M BH-σ* relation and a median Eddington ratio of ~0.7, using stellar velocity dispersions σ* measured from the G band. We estimate the contamination of the stellar continuum from scattered quasar light based on the strength of broad Hβ, and provide an empirical calibration of the contamination as a function of L [O III]; the scattered-light fraction is ~30% of L 5100 for objects with L [O III] = 109.5 L sun. Population synthesis indicates that young poststarburst populations (<0.1 Gyr) are prevalent in luminous type 2 quasars, in addition to a relatively old population (>1 Gyr) which dominates the stellar mass. Broad emission complexes around He II λ4686 Å with luminosities up to 108.3 L sun are unambiguously detected in three out of the nine targets, indicative of Wolf-Rayet (WR) populations. Population synthesis shows that ~5 Myr poststarburst populations contribute substantially to the luminosities (>50% of L 5100) of all three objects with WR detections. We find two objects with double cores and four with close companions. Our results may suggest that luminous type 2 quasars trace an early stage of galaxy interaction, perhaps responsible for both the quasar and the starburst activity. Based, in part, on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Science and Technology Facilities Council (United Kingdom), the National Research Council (Canada

  8. The Circumgalactic Medium of Submillimeter Galaxies. I. First Results from a Radio-identified Sample

    NASA Astrophysics Data System (ADS)

    Fu, Hai; Hennawi, J. F.; Prochaska, J. X.; Mutel, R.; Casey, C.; Cooray, A.; Kereš, D.; Zhang, Z.-Y.; Clements, D.; Isbell, J.; Lang, C.; McGinnis, D.; Michałowski, M. J.; Mooley, K.; Perley, D.; Stockton, A.; Thompson, D.

    2016-11-01

    We present the first results from an ongoing survey to characterize the circumgalactic medium (CGM) of massive high-redshift galaxies detected as submillimeter galaxies (SMGs). We constructed a parent sample of 163 SMG-QSO pairs with separations less than ˜36″ by cross-matching far-infrared-selected galaxies from Herschel with spectroscopically confirmed QSOs. The Herschel sources were selected to match the properties of the SMGs. We determined the sub-arcsecond positions of six Herschel sources with the Very Large Array and obtained secure redshift identification for three of those with near-infrared spectroscopy. The QSO sightlines probe transverse proper distances of 112, 157, and 198 kpc at foreground redshifts of 2.043, 2.515, and 2.184, respectively, which are comparable to the virial radius of the ˜1013 M ⊙ halos expected to host SMGs. High-quality absorption-line spectroscopy of the QSOs reveals systematically strong H i Lyα absorption around all three SMGs, with rest-frame equivalent widths of ˜2-3 Å. However, none of the three absorbers exhibit compelling evidence for optically thick H i gas or metal absorption, in contrast to the dominance of strong neutral absorbers in the CGM of luminous z ˜ 2 QSOs. The low covering factor of optically thick H i gas around SMGs tentatively indicates that SMGs may not have as prominent cool gas reservoirs in their halos as the coeval QSOs and that they may inhabit less massive halos than previously thought.

  9. Lyα imaging of a very luminous z=2.3 starburst galaxy with WFPC2

    NASA Astrophysics Data System (ADS)

    Roche, Nathan; Lowenthal, James; Woodgate, Bruce

    2000-10-01

    residuals - the QSO is consistent with a pure point source and we do not detect either the host galaxy or the damped Lyα absorbing galaxy. We search for other galaxies with strong Lyα emission at z~2.3-2.4, selecting these by colour (m410-V555)AB<-0.2. Eight candidate Lyα sources, all fainter than the Coup Fourré Galaxy, are identified in our field. One is a point-source and may be an AGN; the others are of similar size to the Coup Fourré Galaxy but of lower surface brightness, knotty and asymmetric. They appear typical of Lyman break galaxies but with colours indicating W(Lyα)~100Å.

  10. The ultraviolet spectrum of the gravitational lens candidate UM 425 = QSO 1120+019: Evidence for broad absorption line (BAL) structure

    NASA Technical Reports Server (NTRS)

    Michelitsianos, A. G.; Oliversen, R. J.

    1995-01-01

    The UV line profile structure of high-ionization resonance lines found with the International Ultraviolet Explorer (IUE) in the brightest of four multiply imaged sources (images-A) in the candidate gravitational lens UM 425 = QSO 1120+019 indicates broad absorption line (BAL) structure. The deep-broad trough associated with the O IV line extends to velocities approiximately -12,000 km/s, and contains disrete features that suggest multicomponent velocity structure. This structure may include contributions from C IV absorption from the early-type galaxy that is believed to lens UM 425. A strong absorption feature in the blue wing of the Lyman-alpha lambda 1216 emission line may be a Lyman alpha absorption system at a Z(sub Ly alpha) = 1.437 +/- 0.003, or it may be formed by the superposition of the broad N V lambda lambda 1238, 1242 absorption trough on the extended blue emission wing of the QSO Lyman-alpha line. We obtained a redshift of Z(sub QSO) = 1.471 +/- 0.003 from Lyman-alpha lambda 1215, consistent with the redshift found by Meylan and Djorgovski in the optical. The Lyman-alpha line appears unusally weak due to the presence of N V lambda 1240 BAL absorption. A Lyman-limit absorption system at lambda 912 was not observed in the QSO rest frame. The detection of BAL structure in the other weaker ground-state resonance lines of N II (l) and S IV (l) was not found, suggesting these lines are formed in a region that is distinct from the BAL component. Detection of BAL structure in the other fainter images in this system with Hubble Space Telescope (HST) instrumentation, similar to structure observed here in image A, could provide evidence that UM 425 is a gravitational lens.

  11. Using ISM abundances in the SMC to Correct for Element Depletions by Dust in QSO Absorption Line Systems

    NASA Astrophysics Data System (ADS)

    Jenkins, Edward

    2014-10-01

    The availability of 10-m class telescopes with high resolution echelle spectrographs has enabled astronomers to measure accurately the gas-phase abundances of various elements in QSO absorption line systems at high redshifts. These systems offer insights on the chemical evolution of galaxies (and their nearby environments) in their early stages of development. However, in order to obtain total abundances the observations need to be corrected for the depletions caused by the formation of dust, and traditionally people have done so by using the depletion patterns seen in our own Galaxy. There is now evidence that indicates that such patterns in low-metallicity systems differ from those of our Galaxy and thus the corrections may be misleading. The aim of our proposed HST observations is to measure the gas-phase abundances toward stars in the Small Magellanic Cloud, which is a low-metallicity dwarf galaxy where there exist good measurements of stellar comparison abundances. We plan to record ISM absorption features from STIS medium-resolution echelle spectra for 14 stars in the SMC that are known to have varying levels of depletion, so that we can derive the gas-phase abundance patterns of the elements Ni, Fe, Cr, Mn, Si, Mg, Ge, Kr, Zn, and perhaps P.

  12. SN 2010ay is a Luminous and Broad-lined Type Ic Supernova within a Low-metallicity Host Galaxy

    NASA Technical Reports Server (NTRS)

    Sanders, N. E.; Soderberg, A. M.; Valenti, S.; Chomiuk, L.; Berger, E.; Smartt, S.; Hurley, K.; Barthelmy, S. D.; Chornock, R.; Foley, R. J.; Levesque, E. M.; Narayan, G.; Botticella, M. T.; Briggs, M. S.; Connaughton, V.; Terada, Y.; Gehrels, N.; Golenetskii, S.; Mazets, E.; Cline, T.; von Kienlin, A.; Boynton, W.; Chambers, K. C.; Grav, T.; Heasley, J. N.

    2011-01-01

    We report on our serendipitous pre-discovery detection and detailed follow-up of the broad-lined Type Ic supernova SN2010ay at z approx 0.067 imaged by the Pan-STARRS1 3pi survey just approx 4 days after explosion. Combining our photometric observations with those available in the literature, we estimate the explosion date and the peak luminosity of the SN, M(sub R) approximately equals 20.2 mag, significantly brighter than known GRB-SNe and one of the most luminous SNe Ibc ever discovered. We measure the photospheric expansion velocity of the explosion from our spectroscopic follow-up observations, v(sub ph) approximately equals 19.2 X 10 (exp 3) km/s at approx 40 days after explosion. In comparison with other broad-lined SNe, the characteristic velocity of SN2010ay is 2 - 5 X higher and similar to the measurements for GRB-SNe at comparable epochs. Moreover the velocity declines two times slower than other SNe Ic-BL and GRB-SNe. Assuming that the optical emission is powered by radioactive decay, the peak magnitude implies the synthesis of an unusually large mass of Ni-56, M(sub Ni) = 0.9(+0.1/-0.1) solar mass. Our modeling of the light-curve points to a total ejecta mass, M(sub ej) approx 4.7 Solar Mass, and total kinetic energy, E(sub K,51) approximately equals 11. Thus the ratio of M(sub Ni) to M(sub ej) is at least twice as large for SN2010ay than in GRB-SNe and may indicate an additional energy reservoir. We also measure the metallicity (log(O/H) + 12 = 8.19) of the explosion site within the host galaxy using a high S/N optical spectrum. Our abundance measurement places this SN in the low-metallicity regime populated by GRB-SNe, and approx 0.2(0.5) dex lower than that typically measured for the host environments of normal (broad-lined) Ic supernovae. Despite striking similarities to the recent GRB-SN100316D/2010bh, we show that gamma-ray observations rule out an associated GRB with E(sub gamma) approx < 6 X 10(exp 48) erg (25-150 keV). Similarly, our deep

  13. SN 2010ay Is a Luminous and Broad-Lined Type Ic Supernova Within a Low-Metallicity Host Galaxy

    NASA Technical Reports Server (NTRS)

    Sanders, N. E.; Soderberg, A. M.; Valenti, S.; Foley, R. J.; Chornock, R.; Chomiuk, L.; Berger, E.; Smartt, S.; Hurley, K.; Barthelmy, S. D.; Levesque, E. M.; Narayan, G.; Botticella, M. T.; Briggs, M. S.; Connaughton, V.; Terada, Y.; Gehrels, N.; Golenetskii, S.; Mazets, E.; Cline, T.; von Kienlin, A.; Boynton, W.; Chambers, K. C.; Grav, T.; Heasley, J. N.

    2012-01-01

    We report on our serendipitous pre-discovery detection and follow-up observations of the broad-lined Type Ic supernova (SN Ic) 2010ay at z = 0.067 imaged by the Pan-STARRS1 3pi survey just approximately 4 days after explosion. The supernova (SN) had a peak luminosity, MR approx. -20.2 mag, significantly more luminous than known GRB-SNe and one of the most luminous SNe Ib/c ever discovered. The absorption velocity of SN 2010ay is v Si (is) approx. 19×10(exp 3) km s-1 at approximately 40 days after explosion, 2-5 times higher than other broad-lined SNe and similar to the GRB-SN 2010bh at comparable epochs. Moreover, the velocity declines approximately 2 times slower than other SNe Ic-BL and GRB-SNe. Assuming that the optical emission is powered by radioactive decay, the peak magnitude implies the synthesis of an unusually large mass of 56Ni, MNi = 0.9 solar mass. Applying scaling relations to the light curve, we estimate a total ejecta mass, Mej (is) approx. 4.7 solar mass, and total kinetic energy, EK (is) approx. 11 × 10(exp 51) erg. The ratio of MNi to Mej is approximately 2 times as large for SN 2010ay as typical GRB-SNe and may suggest an additional energy reservoir. The metallicity (log(O/H)PP04 + 12 = 8.19) of the explosion site within the host galaxy places SN 2010ay in the low-metallicity regime populated by GRB-SNe, and (is) approximately 0.5(0.2) dex lower than that typically measured for the host environments of normal (broad-lined) SNe Ic. We constrain any gamma-ray emission with E(gamma) (is) approximately less than 6 × 10(exp 48) erg (25-150 keV), and our deep radio follow-up observations with the Expanded Very Large Array rule out relativistic ejecta with energy E (is) approximately greater than 10(exp 48) erg. We therefore rule out the association of a relativistic outflow like those that accompanied SN 1998bw and traditional long-duration gamma-ray bursts (GRBs), but we place less-stringent constraints on a weak afterglow like that seen from XRF

  14. The Compact, ∼1 kpc Host Galaxy of a Quasar at a Redshift of 7.1

    NASA Astrophysics Data System (ADS)

    Venemans, Bram P.; Walter, Fabian; Decarli, Roberto; Bañados, Eduardo; Hodge, Jacqueline; Hewett, Paul; McMahon, Richard G.; Mortlock, Daniel J.; Simpson, Chris

    2017-03-01

    We present Atacama Large Millimeter/submillimeter Array (ALMA) observations of the [C ii] fine-structure line and the underlying far-infrared (FIR) dust continuum emission in J1120+0641, the most distant quasar currently known (z=7.1). We also present observations targeting the CO(2–1), CO(7–6), and [C i] 369 μm lines in the same source obtained at the Very Large Array and Plateau de Bure Interferometer. We find a [C ii] line flux of {F}[{{C}{{II}}]}=1.11+/- 0.10 Jy {km} {{{s}}}-1 and a continuum flux density of {S}227{GHz}=0.53+/- 0.04 mJy beam‑1, consistent with previous unresolved measurements. No other source is detected in continuum or [C ii] emission in the field covered by ALMA (∼ 25″). At the resolution of our ALMA observations (0.″23, or 1.2 kpc, a factor of ∼70 smaller beam area compared to previous measurements), we find that the majority of the emission is very compact: a high fraction (∼80%) of the total line and continuum flux is associated with a region 1–1.5 kpc in diameter. The remaining ∼20% of the emission is distributed over a larger area with radius ≲4 kpc. The [C ii] emission does not exhibit ordered motion on kiloparsec scales: applying the virial theorem yields an upper limit on the dynamical mass of the host galaxy of (4.3+/- 0.9)× {10}10 {M}ȯ , only ∼20 × higher than the central black hole (BH). The other targeted lines (CO(2–1), CO(7–6), and [C i]) are not detected, but the limits of the line ratios with respect to the [C ii] emission imply that the heating in the quasar host is dominated by star formation, and not by the accreting BH. The star formation rate (SFR) implied by the FIR continuum is 105–340 {M}ȯ {{yr}}-1, with a resulting SFR surface density of ∼100–350 {M}ȯ {{yr}}-1 kpc‑2, well below the value for Eddington-accretion-limited star formation.

  15. NIR flaring of the QSO PKS 2233-148

    NASA Astrophysics Data System (ADS)

    Carrasco, L.; Luna, A.; Mayya, D. Y.; Porras, A.; Recillas, E.; Carraminana, A.

    2012-10-01

    We have observed a recent NIR brightening of the flat spectrum QSO PKS2233-148 (z=0.325), a gamma ray source 2FGL J2236.5-1431. On September 26th, 2012, epoch JD2456196.813507, we determined the flux in the H band to be 13.096 +/- 0.04. That is 2 magnitudes brighter than the flux determined by the 2mass survey. Observations were carried out with the 2.1m telescope of the Guillermo Haro Observatory operated by the National Institute for Astrophysics, Optics and Electronics (Mexico), equipped with the instrument CANICA a NIR camera.

  16. DISCOVERY OF A DAMPED Lyα ABSORBER AT z = 3.3 ALONG A GALAXY SIGHT-LINE IN THE SSA22 FIELD

    SciTech Connect

    Mawatari, K.; Inoue, A. K.; Kousai, K.; Hayashino, T.; Cooke, R.; Prochaska, J. X.; Matsuda, Y.

    2016-02-01

    Using galaxies as background light sources to map the Lyα absorption lines is a novel approach to study Damped Lyα Absorbers (DLAs). We report the discovery of an intervening z = 3.335 ± 0.007 DLA along a galaxy sight-line identified among 80 Lyman Break Galaxy (LBG) spectra obtained with our Very Large Telescope/Visible Multi-Object Spectrograph survey in the SSA22 field. The measured DLA neutral hydrogen (H i) column density is log(N{sub H} {sub i}/cm{sup −2}) = 21.68 ± 0.17. The DLA covering fraction over the extended background LBG is >70% (2σ), yielding a conservative constraint on the DLA area of ≳1 kpc{sup 2}. Our search for a counterpart galaxy hosting this DLA concludes that there is no counterpart galaxy with star formation rate larger than a few M{sub ⊙} yr{sup −1}, ruling out an unobscured violent star formation in the DLA gas cloud. We also rule out the possibility that the host galaxy of the DLA is a passive galaxy with M{sub *} ≳ 5 × 10{sup 10}M{sub ⊙} or a heavily dust-obscured galaxy with E(B − V) ≳ 2. The DLA may coincide with a large-scale overdensity of the spectroscopic LBGs. The occurrence rate of the DLA is compatible with that of DLAs found in QSO sight-lines.

  17. Three intervening galaxy absorbers towards GRB 060418: faint and dusty?

    NASA Astrophysics Data System (ADS)

    Ellison, Sara L.; Vreeswijk, Paul; Ledoux, Cédric; Willis, Jon P.; Jaunsen, Andreas; Wijers, Ralph A. M. J.; Smette, Alain; Fynbo, Johan P. U.; Møller, Palle; Hjorth, Jens; Kaufer, Andreas

    2006-10-01

    We present an analysis of three strong, intervening Mg II absorption systems (zabs = 0.603, 0.656, 1.107) towards the optical afterglow of gamma-ray burst (GRB) 060418. From high-resolution Ultraviolet and Visual Echelle Spectrograph (UVES) spectra we measure metal column densities and find that the highest redshift absorber exhibits a large amount of dust depletion compared with damped Lyman absorbers (DLAs) seen in quasi-stellar object (QSO) spectra. The intervening zabs = 1.107 absorber is also unusual in exhibiting a clear 2175-Å bump, the first time this feature has been definitively detected in a GRB spectrum. The GRB afterglow spectrum is best fitted with a two-component extinction curve: a Small Magellanic Cloud (SMC) extinction law at z = 1.49 (the redshift of the host) with E(B - V) = 0.07 +/- 0.01 and a Galactic extinction curve at z ~ 1.1 with E(B - V) = 0.08 +/- 0.01. We also present a moderately deep New Technology Telescope (NTT) R-band image of the GRB 060418 field and spectroscopy of four galaxies within 1 arcmin. None of these objects has a redshift that matches any of the intervening absorbers, and we conclude that the galaxies responsible for the two intervening MgII absorbers at z ~ 0.6 have luminosities .

  18. On the Formation of Molecular Clumps in QSO Outflows

    NASA Astrophysics Data System (ADS)

    Ferrara, A.; Scannapieco, E.

    2016-12-01

    We study the origin of the cold molecular clumps in quasar outflows, recently detected in CO and HCN emission. We first describe the physical properties of such radiation-driven outflows and show that a transition from a momentum- to an energy-driven flow must occur at a radial distance of R≈ 0.25 {kpc}. During this transition, the shell of swept-up material fragments due to Rayleigh-Taylor instabilities, but these clumps contain little mass and are likely to be rapidly ablated by the hot gas in which they are immersed. We then explore an alternative scenario in which clumps form from thermal instabilities at R≳ 1 {kpc}, possibly containing enough dust to catalyze molecule formation. We investigate this process with 3D two-fluid (gas+dust) numerical simulations of a kpc3 patch of the outflow, including atomic and dust cooling, thermal conduction, dust sputtering, and photoionization from the QSO radiation field. In all cases, dust grains are rapidly destroyed in ≈ {10}4 years; and while some cold clumps form at later times, they are present only as transient features, which disappear as cooling becomes more widespread. In fact, we only find a stable two-phase medium with dense clumps if we artificially enhance the QSO radiation field by a factor of 100. This result, together with the complete destruction of dust grains, renders the interpretation of molecular outflows a very challenging problem.

  19. New Probes with Deep of Gas Flows within Galaxies at Intermediate Redshifts

    NASA Astrophysics Data System (ADS)

    Koo, D. C.

    2012-09-01

    Instead of using background QSO's, we suggest using the light from galaxies to probe cool gas flows within their own halos. We highlight two DEEP projects based on this idea, one by Sato et al. (2009) that uses NaD absorption lines of galaxies at low redshifts z < 0.6 and another by Weiner et al. (2009) that uses MgII lines seen in galaxies at higher redshifts z ˜ 1.4.

  20. MID-INFRARED PROPERTIES OF OH MEGAMASER HOST GALAXIES. I. SPITZER IRS LOW- AND HIGH-RESOLUTION SPECTROSCOPY

    SciTech Connect

    Willett, Kyle W.; Darling, Jeremy; Spoon, Henrik W. W.; Charmandaris, Vassilis; Armus, Lee

    2011-03-15

    We present mid-infrared spectra and photometry from the Infrared Spectrograph on the Spitzer Space Telescope for 51 OH megamasers (OHMs), along with 15 galaxies confirmed to have no megamaser emission above L {sub OH} = 10{sup 2.3} L {sub sun}. The majority of galaxies display moderate-to-deep 9.7 {mu}m amorphous silicate absorption, with OHM galaxies showing stronger average absorption and steeper 20-30 {mu}m continuum emission than non-masing galaxies. Emission from multiple polycyclic aromatic hydrocarbons (PAHs), especially at 6.2, 7.7, and 11.3 {mu}m, is detected in almost all systems. Fine-structure atomic emission (including [Ne II], [Ne III], [S III], and [S IV]) and multiple H{sub 2} rotational transitions are observed in more than 90% of the sample. A subset of galaxies show emission from rarer atomic lines, such as [Ne V], [O IV], and [Fe II]. Fifty percent of the OHMs show absorption from water ice and hydrogenated amorphous carbon grains, while absorption features from CO{sub 2}, HCN, C{sub 2}H{sub 2}, and crystalline silicates are also seen in several OHMs. Column densities of OH derived from 34.6 {mu}m OH absorption are similar to those derived from 1667 MHz OH absorption in non-masing galaxies, indicating that the abundance of masing molecules is similar for both samples. This data paper presents full mid-infrared spectra for each galaxy, along with measurements of line fluxes and equivalent widths, absorption feature depths, and spectral indices.

  1. Variability of GeV gamma-ray emission in QSO B0218+357 due to microlensing on intermediate size structures

    NASA Astrophysics Data System (ADS)

    Sitarek, J.; Bednarek, W.

    2016-06-01

    Strong gravitational lensing leads to an occurrence of multiple images, with different magnifications, of a lensed source. Those magnifications can in turn be modified by microlensing on smaller mass scales within the lens. Recently, measurements of the changes in the magnification ratio of the individual images have been proposed as a powerful tool for estimation of the size and velocity of the emission region in the lensed source. The changes of the magnification ratios in blazars PKS1830-211 and QSO B0218+357, if interpreted as caused by a microlensing on individual stars, put strong constraints on those two variables. These constraints are difficult to accommodate with the current models of gamma-ray emission in blazars. In this paper we study if similar changes in the magnification ratio can be caused by microlensing on intermediate size structures in the lensing galaxy. We investigate in details three classes of possible lenses: globular clusters (GCs), open clusters (OCs) and giant molecular clouds (GMCs). We apply this scenario to the case of QSO B0218+357. Our numerical simulations show that changes in magnifications with similar time-scales can be obtained for relativistically moving emission regions with sizes up to 0.01 pc in the case of microlensing on the cores of GCs or clumps in GMCs. From the density of such structures in spiral galaxies we estimate however that lensing in GMCs would be more common.

  2. Black Hole Caught Zapping Galaxy into Existence?

    NASA Astrophysics Data System (ADS)

    2009-11-01

    across the whole electromagnetic spectrum; particularly spectacular is the case of quasars, where the active core is so overwhelmingly bright that it outshines the luminosity of the host galaxy. [2] This part of the study is based on observations performed at mid-infrared wavelengths, with the powerful VLT spectrometer and imager for the mid-infrared (VISIR) instrument at the VLT, combined with additional data including: spectra acquired using VLT-FORS, optical and infrared images from the NASA/ESA Hubble Space Telescope, and radio observations from the Australia Telescope National Facility. [3] Most galaxies in the local Universe contain a supermassive black hole with a mass about 1/700th the mass of the stellar bulge. The origin of this black hole mass versus stellar mass relation is one of the most debated subjects in modern astrophysics. More information This research was presented in papers published in the journal Astronomy & Astrophysics: "Quasar induced galaxy formation: a new paradigm?" by Elbaz et al., and in the Astrophysical Journal "The QSO HE0450-2958: Scantily dressed or heavily robed? A normal quasar as part of an unusual ULIRG" by Jahnke et al. The team is composed of David Elbaz (Service d'Astrophysique, CEA Saclay, France), Knud Jahnke (Max Planck Institute for Astronomy, Heidelberg, Germany), Eric Pantin (Service d'Astrophysique, CEA Saclay, France), Damien Le Borgne (Paris University 6 and CNRS, Institut d'Astrophysique de Paris, France) and Géraldine Letawe (Institut d'Astrophysique et de Géophysique, Université de Liège, Belgium). ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design

  3. Are long gamma-ray bursts biased tracers of star formation? Clues from the host galaxies of the Swift/BAT6 complete sample of bright LGRBs. II. Star formation rates and metallicities at z < 1

    NASA Astrophysics Data System (ADS)

    Japelj, J.; Vergani, S. D.; Salvaterra, R.; D'Avanzo, P.; Mannucci, F.; Fernandez-Soto, A.; Boissier, S.; Hunt, L. K.; Atek, H.; Rodríguez-Muñoz, L.; Scodeggio, M.; Cristiani, S.; Le Floc'h, E.; Flores, H.; Gallego, J.; Ghirlanda, G.; Gomboc, A.; Hammer, F.; Perley, D. A.; Pescalli, A.; Petitjean, P.; Puech, M.; Rafelski, M.; Tagliaferri, G.

    2016-05-01

    Aims: Long gamma-ray bursts (LGRBs) are associated with the deaths of massive stars and might therefore be a potentially powerful tool for tracing cosmic star formation. However, especially at low redshifts (z< 1.5) LGRBs seem to prefer particular types of environment. Our aim is to study the host galaxies of a complete sample of bright LGRBs to investigate the effect of the environment on GRB formation. Methods: We studied host galaxy spectra of the Swift/BAT6 complete sample of 14 z< 1 bright LGRBs. We used the detected nebular emission lines to measure the dust extinction, star formation rate (SFR), and nebular metallicity (Z) of the hosts and supplemented the data set with previously measured stellar masses M⋆. The distributions of the obtained properties and their interrelations (e.g. mass-metallicity and SFR-M⋆ relations) are compared to samples of field star-forming galaxies. Results: We find that LGRB hosts at z< 1 have on average lower SFRs than if they were direct star formation tracers. By directly comparing metallicity distributions of LGRB hosts and star-forming galaxies, we find a good match between the two populations up to 12 +log ≤ft( frac{OHright)} 8.4-8.5, after which the paucity of metal-rich LGRB hosts becomes apparent. The LGRB host galaxies of our complete sample are consistent with the mass-metallicity relation at similar mean redshift and stellar masses. The cutoff against high metallicities (and high masses) can explain the low SFR values of LGRB hosts. We find a hint of an increased incidence of starburst galaxies in the Swift/BAT6 z< 1 sample with respect to that of a field star-forming population. Given that the SFRs are low on average, the latter is ascribed to low stellar masses. Nevertheless, the limits on the completeness and metallicity availability of current surveys, coupled with the limited number of LGRB host galaxies, prevents us from investigating more quantitatively whether the starburst incidence is such as expected

  4. Gas dynamical imaging and dust properties of the strongly-lensed quasar host galaxy RXJ1131-1231 at z~0.65

    NASA Astrophysics Data System (ADS)

    Leung, Tsz Kuk Daisy; Riechers, Dominik; Pavesi, Riccardo

    2017-01-01

    that its black hole mass is largely in place while its stellar bulge is still assembling. Our results thus support the emerging picture that quasars grow faster and/or earlier than their host galaxies at earlier epochs.

  5. The Large Area Radio Galaxy Evolution Spectroscopic Survey (LARGESS): survey design, data catalogue and GAMA/WiggleZ spectroscopy

    NASA Astrophysics Data System (ADS)

    Ching, John H. Y.; Sadler, Elaine M.; Croom, Scott M.; Johnston, Helen M.; Pracy, Michael B.; Couch, Warrick J.; Hopkins, A. M.; Jurek, Russell J.; Pimbblet, K. A.

    2017-01-01

    We present the Large Area Radio Galaxy Evolution Spectroscopic Survey (LARGESS), a spectroscopic catalogue of radio sources designed to include the full range of radio AGN populations out to redshift z ˜ 0.8. The catalogue covers ˜800 deg2 of sky, and provides optical identifications for 19 179 radio sources from the 1.4 GHz Faint Images of the Radio Sky at Twenty-cm (FIRST) survey down to an optical magnitude limit of imod < 20.5 in Sloan Digital Sky Survey (SDSS) images. Both galaxies and point-like objects are included, and no colour cuts are applied. In collaboration with the WiggleZ and Galaxy And Mass Assembly (GAMA) spectroscopic survey teams, we have obtained new spectra for over 5000 objects in the LARGESS sample. Combining these new spectra with data from earlier surveys provides spectroscopic data for 12 329 radio sources in the survey area, of which 10 856 have reliable redshifts. 85 per cent of the LARGESS spectroscopic sample are radio AGN (median redshift z = 0.44), and 15 per cent are nearby star-forming galaxies (median z = 0.08). Low-excitation radio galaxies (LERGs) comprise the majority (83 per cent) of LARGESS radio AGN at z < 0.8, with 12 per cent being high-excitation radio galaxies (HERGs) and 5 per cent radio-loud QSOs. Unlike the more homogeneous LERG and QSO sub-populations, HERGs are a heterogeneous class of objects with relatively blue optical colours and a wide dispersion in mid-infrared colours. This is consistent with a picture in which most HERGs are hosted by galaxies with recent or ongoing star formation as well as a classical accretion disc.

  6. Chandra X-Ray and Hubble Space Telescope Imaging of Optically Selected Kiloparsec-scale Binary Active Galactic Nuclei. II. Host Galaxy Morphology and AGN Activity

    NASA Astrophysics Data System (ADS)

    Shangguan, Jinyi; Liu, Xin; Ho, Luis C.; Shen, Yue; Peng, Chien Y.; Greene, Jenny E.; Strauss, Michael A.

    2016-05-01

    Binary active galactic nuclei (AGNs) provide clues to how gas-rich mergers trigger and fuel AGNs and how supermassive black hole (SMBH) pairs evolve in a gas-rich environment. While significant effort has been invested in their identification, the detailed properties of binary AGNs and their host galaxies are still poorly constrained. In a companion paper, we examined the nature of ionizing sources in the double nuclei of four kiloparsec-scale binary AGNs with redshifts between 0.1 and 0.2. Here, we present their host galaxy morphology based on F336W (U-band) and F105W (Y-band) images taken by the Wide Field Camera 3 on board the Hubble Space Telescope. Our targets have double-peaked narrow emission lines and were confirmed to host binary AGNs with follow-up observations. We find that kiloparsec-scale binary AGNs occur in galaxy mergers with diverse morphological types. There are three major mergers with intermediate morphologies and a minor merger with a dominant disk component. We estimate the masses of the SMBHs from their host bulge stellar masses and obtain Eddington ratios for each AGN. Compared with a representative control sample drawn at the same redshift and stellar mass, the AGN luminosities and Eddington ratios of our binary AGNs are similar to those of single AGNs. The U - Y color maps indicate that clumpy star-forming regions could significantly affect the X-ray detection of binary AGNs, e.g., the hardness ratio. Considering the weak X-ray emission in AGNs triggered in merger systems, we suggest that samples of X-ray-selected AGNs may be biased against gas-rich mergers. Based, in part, on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program number GO 12363.

  7. FOS Observations of the QSO 1442+101 (OQ 172)

    NASA Astrophysics Data System (ADS)

    Lyons, R. W.; Beaver, E. A.; Burbidge, E. M.; Cohen, R. D.; Junkkarinen, V. T.

    1992-12-01

    Low resolution far-UV spectra of the high redshift (zem=3.54) QSO OQ172 have been obtained with the prism and the G160L grating of the Faint Object Spectrograph on board the Hubble Space Telescope. Light is detected down to a rest wavelength near 323 Angstroms where the spectrum appears to be cut off, possibly by a Lyman limit system. This cutoff is only 18000 km sec(-1) in velocity units longward of the predicted He II lambda 304 feature (the He II lambda 304 Gunn-Peterson effect and the He II lambda 304 forest). A partial Lyman limit is observed near 2800 Angstroms. The UV spectra have been combined with Lick CCD optical spectra to determine the shape of the continuum short of Lyalpha and the applicability to it of the ``Lyman valley'' model presented by M\\o ller and Jakobsen (A&A 228, 299, 1990).

  8. On the identification of deuterium lines in QSO absorption systems

    NASA Astrophysics Data System (ADS)

    Levshakov, S. A.; Takahara, F.

    1996-07-01

    The ambiguity of identification of deuterium lines in QSO absorption systems is considered, under the assumption that the D I and H I absorption lines are formed in turbulent media with a finite correlation length of the stochastic velocity field. The relative shift of the D I and H I lines is shown to vary over the range +/-(4-8) km s^- 1^ for a cloud model with hydrogen column density N_HI_ = 10^17^ cm^-2^, the ratio D/H = 10^-4^, and kinetic temperature T_kin_ = 10^4^ K. The variations in the relative shift of the deuterium lines are fundamental in character and result from the stochastic nature of the formation of absorption lines in turbulent media

  9. A catalogue of absorption-line systems in QSO spectra

    NASA Astrophysics Data System (ADS)

    Ryabinkov, A. I.; Kaminker, A. D.; Varshalovich, D. A.

    2003-12-01

    We present a new catalog of absorption-line systems identified in the quasar spectra. It contains data on 821 QSOs and 8558 absorption systems comprising 16 139 absorption lines with measured redshifts in the QSO spectra. The catalog includes absorption-line systems consisting of lines of heavy elements, lines of neutral hydrogen, Lyman limit systems, damped Lyα absorption systems, and broad absorption-line systems. Using the data of the present catalog we also discuss redshift distributions of absorption-line systems. Tables 1 and 2 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/412/707

  10. The KMOS AGN Survey at High redshift (KASHz): the prevalence and drivers of ionized outflows in the host galaxies of X-ray AGN

    NASA Astrophysics Data System (ADS)

    Harrison, C. M.; Alexander, D. M.; Mullaney, J. R.; Stott, J. P.; Swinbank, A. M.; Arumugam, V.; Bauer, F. E.; Bower, R. G.; Bunker, A. J.; Sharples, R. M.

    2016-02-01

    We present the first results from the KMOS (K-band Multi-Object Spectrograph) AGN (active galactic nuclei) Survey at High redshift (KASHz), a VLT/KMOS integral-field spectroscopic (IFS) survey of z ≳ 0.6 AGN. We present galaxy-integrated spectra of 89 X-ray AGN (L2-10 keV = 1042-1045 erg s-1), for which we observed [O III] (z ≈ 1.1-1.7) or Hα emission (z ≈ 0.6-1.1). The targets have X-ray luminosities representative of the parent AGN population and we explore the emission-line luminosities as a function of X-ray luminosity. For the [O III] targets, ≈50 per cent have ionized gas velocities indicative of gas that is dominated by outflows and/or highly turbulent material (i.e. overall line widths ≳600 km s-1). The most luminous half (i.e. LX > 6 × 1043 erg s-1) have a ≳2 times higher incidence of such velocities. On the basis of our results, we find no evidence that X-ray obscured AGN are more likely to host extreme kinematics than unobscured AGN. Our KASHz sample has a distribution of gas velocities that is consistent with a luminosity-matched sample of z < 0.4 AGN. This implies little evolution in the prevalence of ionized outflows, for a fixed AGN luminosity, despite an order-of-magnitude decrease in average star formation rates over this redshift range. Furthermore, we compare our Hα targets to a redshift-matched sample of star-forming galaxies and despite a similar distribution of Hα luminosities and likely star formation rates, we find extreme ionized gas velocities are up to ≈10 times more prevalent in the AGN-host galaxies. Our results reveal a high prevalence of extreme ionized gas velocities in high-luminosity X-ray AGN and imply that the most powerful ionized outflows in high-redshift galaxies are driven by AGN activity.

  11. UVES/VLT high resolution absorption spectroscopy of the GRB 080330 afterglow: a study of the GRB host galaxy and intervening absorbers

    NASA Astrophysics Data System (ADS)

    D'Elia, V.; Fiore, F.; Perna, R.; Krongold, Y.; Vergani, S. D.; Campana, S.; Covino, S.; D'Avanzo, P.; Fugazza, D.; Goldoni, P.; Guidorzi, C.; Meurs, E. J. A.; Norci, L.; Piranomonte, S.; Tagliaferri, G.; Ward, P.

    2009-08-01

    Aims: We study the gamma-ray burst (GRB) environment and intervening absorbers by analyzing the optical absorption features produced by gas surrounding the GRB or along its line of sight. Methods: We analyzed high resolution spectroscopic observations (R = 40 000, S/N = 3-6) of the optical afterglow of GRB 080330, taken with UVES at the VLT ~ 1.5 h after the GRB trigger. Results: The spectrum illustrates the complexity of the ISM of the GRB host galaxy at z = 1.51 which has at least four components in the main absorption system. We detect strong FeII, SiII, and NiII excited absorption lines associated with the bluemost component only. In addition to the host galaxy, at least two more absorbers lying along the line of sight to the afterglow have been detected in the redshift range 0.8 < z < 1.1, each exhibiting MgII absorption. For the bluemost component in the host galaxy, we derive information about its distance from the site of the GRB explosion. We do so by assuming that the excited absorption lines are produced by indirect UV pumping, and compare the data with a time dependent photo-excitation code. The distance of this component is found to be ˜ 280+40-50 pc, which is lower than found for other GRBs (1-6 kpc). We identify two additional MgII absorbers, one of them with a rest frame equivalent width larger than 1 Å. Conclusions: The distance between the GRB and the absorber measured in this paper confirms that the power of the GRB radiation can influence the conditions of the interstellar medium up to a distance of at least several hundred pc. For the intervening absorbers, we confirm the trend that on average one strong intervening system is found per afterglow, as has been noted in studies exhibiting an excess of strong MgII absorbers along GRB sightlines compared to quasars. Based on observations collected at the European Southern Observatory, ESO, the VLT/Kueyen telescope, Paranal, Chile, in the framework of programs 080.A-0398.

  12. High Resolution Simulations for Hierarchical Formation of Dark Matter Halos Hosting Galaxies and AGNs at High Redshift

    NASA Astrophysics Data System (ADS)

    Ishiyama, Tomoaki

    2015-08-01

    We present the evolution of dark matter halos in six large cosmological N-body simulations, called the ν2GC (New Numerical Galaxy Catalog) simulations on the basis of the LCDM cosmology consistent with observational results obtained by the Planck satellite. The largest simulation consists of 81923 (550 billion) dark matter particles in a box of 1.12h-1Gpc (a mass resolution of 2.20×108 h-1M⊙). Among simulations utilizing boxes larger than 1h-1Gpc, our simulation yields the highest resolution simulation that has ever been achieved. Compared with the Millennium simulation (Springel et al. 2005), our simulation offers the advantages of a mass resolution that is four times better and a spatial volume that is 11 times larger. A ν2GC simulation with the smallest box consists of eight billions particles in a box of 70h-1Mpc (a mass resolution of 3.44×106 -1M⊙). These simulations can follow the evolution of halos over masses of eight orders of magnitude, from small dwarf galaxies to massive clusters. Using the unprecedentedly high resolution and powerful statistics of the ν2GC simulations, we provide statistical results of the halo mass function, mass accretion rate, formation redshift, and merger statistics, and present accurate fitting functions for the Planck cosmology, from redshift 10 to 0. By combining the ν2GC simulations with our new semi-analytic galaxy formation model, we are able to prepare mock catalogs of galaxies and active galactic nuclei, which will be made publicly available in the near future.

  13. Resolving the inner structure of QSO discs through fold-caustic-crossing events

    NASA Astrophysics Data System (ADS)

    Abolmasov, P.; Shakura, N. I.

    2012-06-01

    Although the bulk of the observed optical flux from the discs of intermediate-redshift lensed quasars is formed well outside the region of strong relativistic boosting and light bending, relativistic effects have an important influence on microlensing curves. The reason lies in the divergent nature of amplification factors near fold caustics, which are increasingly sensitive to small spatial size details. Higher-order disc images produced by strong light bending around the black hole may affect the amplification curves, making a contribution of up to several per cent near maximum amplification. In accordance with theoretical predictions, some of the observed high-amplification events possess fine structure. Here we consider three putative caustic-crossing events, one by SBS J1520+530 and two events for individual images of Einstein's cross (QSO J2237+0305). Using relativistic disc models allows us to improve the fits but the required inclinations are high, ?. Such high inclinations apparently contradict the absence of any strong absorption that is likely to arise if a disc is observed edge-on through a dust torus. Still, high inclinations are required only for the central parts of the disc, which allows the disc itself initially to be tilted by 60-90° with respect to the black hole and aligned toward the black hole equatorial plane near the last stable orbit radius. For SBS J1520+530, an alternative explanation for the observed amplification curve is a superposition of two subsequent fold-caustic crossings. While relativistic disc models favour black hole masses ˜1010 M⊙ (several times higher than the virial estimates) or small Eddington ratios, this model is consistent with the observed distribution of galaxies over peculiar velocities only if the black hole mass is ?.

  14. Spectroscopy of quasar host galaxies at the VLT: stellar populations and dynamics down to the central kiloparsec

    NASA Astrophysics Data System (ADS)

    Courbin, F.; Letawe, G.; Magain, P.; Wisotzki, L.; Jablonka, P.; Alloin, D.; Jahnke, K.; Kuhlbrodt, B.; Meylan, G.; Minniti, D.

    2002-03-01

    1. Scientific Context 2. VLT Spectroscopic Observations 3. Spectra Decomposition and Stellar Population 4. Dynamics of the Host 5. Towards 2D Spectroscopy and High Spatial Resolution: GIRAFFE, SINFONI and FALCON

  15. Quasars Probing Quasars. VIII. The Physical Properties of the Cool Circumgalactic Medium Surrounding z ~ 2-3 Massive Galaxies Hosting Quasars

    NASA Astrophysics Data System (ADS)

    Lau, Marie Wingyee; Prochaska, J. Xavier; Hennawi, Joseph F.

    2016-10-01

    We characterize the physical properties of the cool T ˜ 104 K circumgalactic medium (CGM) surrounding z ˜ 2-3 quasar host galaxies, which are predicted to evolve into present-day massive ellipticals. Using a statistical sample of 14 quasar pairs with projected separation <300 kpc and spectra of high dispersion and high signal-to-noise ratio, we find extreme kinematics with low metal ion lines typically spanning ≈500 km s-1, exceeding any previously studied galactic population. The CGM is significantly enriched, even beyond the virial radius, with a median metallicity [M/H] ≈ -0.6. The α/Fe abundance ratio is enhanced, suggesting that halo gas is primarily enriched by core-collapse supernovae. The projected cool gas mass within the virial radius is estimated to be 1.9 × 1011 M ⊙ (R ⊥/160 kpc)2, accounting for ≈1/3 of the baryonic budget of the galaxy halo. The ionization state of CGM gas increases with projected distance from the foreground quasars, contrary to expectation if the quasar dominates the ionizing radiation flux. However, we also found peculiarities not exhibited in the CGM of other galaxy populations. In one absorption system, we may be detecting unresolved fluorescent Lyα emission, and another system shows strong N v lines. Taken together, these anomalies suggest that transverse sightlines are—at least in some cases—possibly illuminated. We also discovered a peculiar case where detection of the C ii fine-structure line implies an electron density >100 cm-3 and sub-parsec-scale gas clumps.

  16. A Ringed Dwarf LINER 1 Galaxy Hosting an Intermediate-mass Black Hole with Large-scale Rotation-like Hα Emission

    NASA Astrophysics Data System (ADS)

    Liu, Wen-Juan; Qian, Lei; Dong, Xiao-Bo; Jiang, Ning; Lira, Paulina; Cai, Zheng; Wang, Feige; Yang, Jinyi; Xiao, Ting; Kim, Minjin

    2017-03-01

    We report the discovery of a 20 kpc sized {{H}}α emission in SDSS J083803.68+540642.0, a ringed dwarf galaxy ({M}V=-17.89 mag) hosting an accreting intermediate-mass black hole at z = 0.02957. Analysis of the Hubble Space Telescope images indicates that it is an early-type galaxy with a featureless low-surface brightness disk ({μ }0=20.39 mag arcsec‑2 in the V band) and a prominent, relatively red bulge (V ‑ I = 2.03, {R}{{e}}=0.28 {kpc} or 0.″48) that accounts for ≈81% of the total light in the I band. A circumgalactic ring of a diameter 16 kpc is also detected, with a disperse shape on its south side. The optical emission lines reveal the nucleus to be a broad-line LINER. Our MMT longslit observation indicates that the kinematics of the extended {{H}}α emission is consistent with a rotational gaseous disk, with a mean blueshifted velocity of 162 {km} {{{s}}}-1 and mean redshifted velocity of 86 {km} {{{s}}}-1. According to our photoionization calculations, the large-scale {{H}}α emission is unlikely to be powered by the central nucleus or by hot evolved (post-AGB) stars interspersed in the old stellar populations, but by in situ star formation; this is vindicated by the line-ratio diagnostic of the extended emission. We propose that both the ring and large-scale {{H}}α -emitting gas are created by the tidal accretion in a collision—and then merger—with a gas-rich galaxy of a comparable mass.

  17. REDSHIFT 6.4 HOST GALAXIES OF 10{sup 8} SOLAR MASS BLACK HOLES: LOW STAR FORMATION RATE AND DYNAMICAL MASS

    SciTech Connect

    Willott, Chris J.; Omont, Alain; Bergeron, Jacqueline

    2013-06-10

    We present Atacama Large Millimeter Array observations of rest-frame far-infrared continuum and [C II] line emission in two z = 6.4 quasars with black hole masses of Almost-Equal-To 10{sup 8} M{sub Sun }. CFHQS J0210-0456 is detected in the continuum with a 1.2 mm flux of 120 {+-} 35 {mu}Jy, whereas CFHQS J2329-0301 is undetected at a similar noise level. J2329-0301 has a star formation rate limit of <40 M{sub Sun} yr{sup -1}, considerably below the typical value at all redshifts for this bolometric luminosity. Through comparison with hydro simulations, we speculate that this quasar is observed at a relatively rare phase where quasar feedback has effectively shut down star formation in the host galaxy. [C II] emission is also detected only in J0210-0456. The ratio of [C II] to far-infrared luminosity is similar to that of low-redshift galaxies of comparable luminosity, suggesting that the previous finding of an offset in the relationships between this ratio and far-infrared luminosity at low and high redshifts may be partially due to a selection effect due to the limited sensitivity of previous continuum data. The [C II] line of J0210-0456 is relatively narrow (FWHM = 189 {+-} 18 km s{sup -1}), indicating a dynamical mass substantially lower than expected from the local black hole-velocity dispersion correlation. The [C II] line is marginally resolved at 0.''7 resolution with the blue and red wings spatially offset by 0.''5 (3 kpc) and a smooth velocity gradient of 100 km s{sup -1} across a scale of 6 kpc, possibly due to the rotation of a galaxy-wide disk. These observations are consistent with the idea that stellar mass growth lags black hole accretion for quasars at this epoch with respect to more recent times.

  18. Frequency of Oxygen VI in Intervening QSO Absorption Systems

    NASA Astrophysics Data System (ADS)

    Burles, Scott; Tytler, David

    1994-12-01

    We have conducted the first survey for QSO with O VI lambda lambda 1032,1038 absorption lines. We obtained medium resolution (R ~ 1300), high signal-to-noise (~ 20) spectra of 11 QSOs (0.53<= zem <=2.08) taken with the Faint Object Spectrograph from the Hubble Space Telescope Archive. The O VI doublet is found exclusively in the Lyman-alpha forest. All previous surveys of metal lines in QSO absorption systems were done redward of Lyalpha emission, avoiding blending due to Lyman-alpha forest clouds. The higher density of lines in the Lyman-alpha forest demands new stringent criteria to ensure the identification of the O VI doublet. We used simulated spectra to determine the statistical significance of lines indentified in the Lyman-alpha forest. We found 12 O VI doublets and 9 are expected to be real. Six constitute a uniform sample with both lines exceeding a rest equivalent width of W_r =0.21 Angstroms. The number of O VI doublets per unit redshift is = 1.0 +/-0.6 at a mean absorption redshift of zave = 0.9. For comparable W_r the density of O VI absorbers is similar to Mg II (Tytler et al 1986; Steidel & Sargent 1992) and C IV absorbers (Sargent et al 1988; Bahcall et al 1993). We searched for other common ions in the O VI absorption systems. Out of 8 O VI absorption systems in which C IV is also found, C IV is stronger in all except zabs=1.0828 towards PG1206+459 which we believe is collisionally ionized. A rough estimate of the cosmological mass density of O VI is carried out. If we assume that O VI lines are linear, we get a lower limit of Omega (OVI) >= 3 times 10(-9) h(-1}_{100) . Since O > O VI, if the mean metal abundance were below 0.002 solar, then the accompanying Hydrogen and Helium would account for all baryons in the universe. We conclude that mean abundances are above 0.002 solar, and much greater if the gas is not highly ionized (O >> O VI).

  19. A Massive Molecular Gas Reservoir in the Z = 2.221 Type-2 Quasar Host Galaxy SMM J0939+8315 Lensed by the Radio Galaxy 3C220.3

    NASA Astrophysics Data System (ADS)

    Leung, T. K. Daisy; Riechers, Dominik A.

    2016-02-01

    We report the detection of CO(J = 3 \\to 2) line emission in the strongly lensed submillimeter galaxy (SMG) SMM J0939+8315 at z = 2.221, using the Combined Array for Research in Millimeter-wave Astronomy. SMM J0939+8315 hosts a type-2 quasar, and is gravitationally lensed by the radio galaxy 3C220.3 and its companion galaxy at z = 0.685. The 104 GHz continuum emission underlying the CO line is detected toward 3C220.3 with an integrated flux density of Scont = 7.4 ± 1.4 mJy. Using the CO(J = 3 \\to 2) line intensity of ICO(3-2) = (12.6 ± 2.0) Jy km s-1, we derive a lensing- and excitation-corrected CO line luminosity of {L}{{CO(1-0)}}\\prime = (3.4 ± 0.7) × 1010 (10.1/μL) K km s-1 pc2 for the SMG, where μL is the lensing magnification factor inferred from our lens modeling. This translates to a molecular gas mass of Mgas = (2.7 ± 0.6) × 1010 (10.1/μL) M⊙. Fitting spectral energy distribution models to the (sub)-millimeter data of this SMG yields a dust temperature of T = 63.1{}-1.3+1.1 K, a dust mass of Mdust = (5.2 ± 2.1) × 108 (10.1/μL) M⊙, and a total infrared luminosity of LIR = (9.1 ± 1.2) ×1012 (10.1/μL) L⊙. We find that the properties of the interstellar medium of SMM J0939+8315 overlap with both SMGs and type-2 quasars. Hence, SMM J0939+8315 may be transitioning from a starbursting phase to an unobscured quasar phase as described by the “evolutionary link” model, according to which this system may represent an intermediate stage in the evolution of present-day galaxies at an earlier epoch.

  20. X-ray-selected AGNs near bright galaxies

    NASA Technical Reports Server (NTRS)

    Stocke, John T.; Schneider, Peter; Morris, Simon L.; Gioia, Isabella M.; Maccacaro, Tommaso

    1987-01-01

    Among the numerous low-redshift low-luminosity X-ray sources discovered with the Einstein Observatory, ten AGNs were identified that are projected within three optical diameters of bright (V less than 18) foreground galaxies. These AGNs 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 AGNs, allowing their detection. It is suggested that microlensing may be responsible for a significant alteration of the inherent QSO luminosity function.

  1. Intergalactic medium emission observations with the cosmic web imager. I. The circum-QSO medium of QSO 1549+19, and evidence for a filamentary gas inflow

    SciTech Connect

    Martin, D. Christopher; Chang, Daphne; Matuszewski, Matt; Morrissey, Patrick; Rahman, Shahin; Moore, Anna; Steidel, Charles C.

    2014-05-10

    The Palomar Cosmic Web Imager (PCWI), an integral field spectrograph designed to detect and map low surface brightness emission, has obtained imaging spectroscopic maps of Lyα from the circum-QSO medium (CQM) of QSO HS1549+19 at redshift z = 2.843. Extensive extended emission is detected from the CQM, consistent with fluorescent and pumped Lyα produced by the ionizing and Lyα continuum of the QSO. Many features present in PCWI spectral images match those detected in narrow-band images. Filamentary structures with narrow line profiles are detected in several cases as long as 250-400 kpc. One of these is centered at a velocity redshifted with respect to the systemic velocity, and displays a spatially collimated and kinematically cold line profile increasing in velocity width approaching the QSO. This suggests that the filament gas is infalling onto the QSO, perhaps in a cold accretion flow. Because of the strong ionizing flux, the neutral column density is low, typically N(H I)∼10{sup 12}--10{sup 15} cm{sup −2}, and the line center optical depth is also low (typically τ{sub 0} < 10), insufficient to display well separated double peak emission characteristic of higher line optical depths. With a simple ionization and cloud model we can very roughly estimate the total gas mass (log M {sub gas} = 12.5 ± 0.5) and the total (log M {sub tot} = 13.3 ± 0.5). We can also calculate a kinematic mass from the total line profile (2 × 10{sup 13} M {sub ☉}), which agrees with the mass estimated from the gas emission. The intensity-binned spectrum of the CQM shows a progression in kinematic properties consistent with heirarchical structure formation.

  2. Comparing Narrow- and Broad-line AGNs in a New Diagnostic Diagram for Emission-line Galaxies Based on WISE Data

    NASA Astrophysics Data System (ADS)

    Coziol, R.; Torres-Papaqui, J. P.; Andernach, H.

    2015-06-01

    increases in the host galaxies of emission-line galaxies with different activity types along the sequence BL Lac \\to LINER \\to QSO/Sy1 \\to Sy2 \\to TO \\to SFG.

  3. The Early Universe Probed by QSO Absorption Lines

    NASA Astrophysics Data System (ADS)

    Misawa, Toru; Iye, Masanori

    2000-12-01

    High-z QSOs are valuable probes of the early universe and provide us information on the era of galaxy formation. QSOs can also be used as background sources against intervening objects such as proto-galactic clouds and faint foreground galaxies. These intervening objects produce absorption lines in the spectra of background QSOs. Gas clouds producing metal absorption lines are thought to exist in the halos of intervening galaxies and are used to evaluate the metal abundances of galaxies at high redshifts. In the course of studying the evolution of metal absorption lines, it was found that the number of absorbers per unit redshift interval increases in the vicinity of QSOs, especially of radio-loud QSOs. The reason of such an excess of metal absorption lines remains still unclear. In this paper, the authors review the absorption properties and enigmas of quasar absorption lines.

  4. The x ray properties of a large, uniform QSO sample: Einstein observations of the LBQS

    NASA Technical Reports Server (NTRS)

    Margon, B.; Anderson, S. F.; Xu, X.; Green, P. J.; Foltz, C. B.

    1992-01-01

    Although there are large numbers of Quasi Stellar Objects (QSO's) now observed in X rays, extensive X-ray observations of uniformly selected, 'complete' QSO samples are more rare. The Large Bright QSO Survey (LBQS) consists of about 1000 objects with well understood properties, most brighter than B = 18.8 and thus amenable to X-ray detections in relatively brief exposures. The sample is thought to be highly complete in the range 0.2 less than z less than 3.3, a significantly broader interval than many other surveys. The Einstein IPC observed 150 of these objects, mostly serendipitously, during its lifetime. We report the results of an analysis of these IPC data, considering not only the 20 percent of the objects we find to have positive X-ray detections, but also the ensemble X-ray properties derived by 'image stacking'.

  5. Monitoring of the extreme alpha_ox variations in the luminous NL QSO PHL 1092

    NASA Astrophysics Data System (ADS)

    Miniutti, Giovanni

    2009-10-01

    During a 2008 XMM-Newton observation the luminous Narrow-Line quasar PHL 1092 showed a dramatic X-ray flux drop by a factor ~200 with respect to previous X-ray observations, becoming one of the most extreme X-ray weak QSO (alpha_ox = -2.44), after being X-ray "normal" (alpha_ox = -1.56) only 4.5 years earlier. Note that the extreme 2008 X-ray weakness corresponds to a factor ~320 with respect to the expected X-ray flux of QSO with the given luminosity. The aim of this proposal is to continue our UV and X-ray monitoring of this extreme source with two 25 ks exposures (one for each visibility window, hence separated by about 6 months) to unveil the timescale over which transitions from X-ray weak to normal QSO states take place in this most extraordinary AGN.

  6. The Tip of the red giant branch distance to the perfect spiral galaxy M74 hosting three core-collapse supernovae

    SciTech Connect

    Sung Jang, In; Gyoon Lee, Myung E-mail: mglee@astro.snu.ac.kr

    2014-09-01

    M74 (NGC 628) is a famous face-on spiral galaxy, hosting three core-collapse supernovae (SNe): SN Ic 2002ap, SN II-P 2003gd, and SN II-P 2013ej. However, its distance is not well known. We present a distance estimation for this galaxy based on the Tip of the Red Giant Branch (TRGB) method. We obtain photometry of the resolved stars in the arm-free region of M74 from F555W and F814W images in the Hubble Space Telescope archive. The color-magnitude diagram of the resolved stars shows a dominant red giant branch (RGB) as well as blue main sequence stars, red helium burning stars, and asymptotic giant branch stars. The I-band luminosity function of the RGB stars shows the TRGB to be at I {sub TRGB} = 26.13 ± 0.03 mag, and T {sub RGB} = 25.97 ± 0.03. From this, we derive the distance modulus to M74 to be 30.04 ± 0.04 (random) ± 0.12 (systematic) (corresponding to a linear distance of 10.19 ± 0.14 ± 0.56 Mpc). With this distance estimate, we calibrate the standardized candle method for SNe II-P. From the absolute magnitudes of SN 2003gd, we derive a value of the Hubble constant, H {sub 0} = 72 ± 6 (random) ± 7 (systematic) km s{sup –1} Mpc{sup –1}. It is similar to recent estimates based on the luminosity calibration of Type Ia supernovae.

  7. Starburst activity in the host galaxy of the z =2.58 quasar J1409+5628

    NASA Astrophysics Data System (ADS)

    Beelen, A.; Cox, P.; Pety, J.; Carilli, C. L.; Bertoldi, F.; Momjian, E.; Omont, A.; Petitjean, P.; Petric, A. O.

    2004-08-01

    We report the detection of CO emission from the optically luminous, radio-quiet quasar J140955.5+562827 (hereafter J1409+5628), at a redshift zCO =2.583. We also present VLA continuum maps and VLBA high spatial resolution observations at 1.4 GHz. Both the CO(3->2) and CO(7->6) emission lines are detected using the IRAM Plateau de Bure interferometer. The 3->2/7->6 line luminosity ratio is about 1/3, indicating the presence of warm and dense molecular gas with an estimated mass of 6 × 1010 M⊙. The infrared-to-CO luminosity ratio LFIR/L'CO(1->0) ≈ 500 L⊙ (K km s-1 pc2)-1, comparable to values found for other high-z sources where CO line emission is seen. J1409+5628 is detected using the VLA with a 1.4 GHz rest-frame luminosity density of 4.0 × 1025 W Hz-1. The rest-frame radio to far-infrared ratio, q, has a value of 2.0 which is similar to the values found in star forming galaxies. At the 30 mas resolution of the VLBA, J1409+5628 is not detected with a 4σ upper limit to the surface brightness of 0.29 mJy beam-1. This implies a limit to the intrinsic brightness temperature of 2 × 105 K at 8 GHz, typical for nuclear starbursts and more than two orders of magnitude fainter than typical radio-loud active galactic nuclei. Both the properties of the CO line emission and the radio emission from J1409+5628 are therefore consistent with those expected for a star forming galaxy. In J1409+5628 young massive stars are the dominant source of dust heating, accounting for most of the infrared luminosity. The massive reservoir of molecular gas can sustain the star formation rate of a few 1000 M⊙ yr-1 implied by the far-infrared luminosity for about 10 million years. This paper is based on observations obtained with the IRAM Plateau de Bure Interferometer. IRAM is funded by Centre National de la Recherche Scientifique (France), the Max-Planck-Gesellschaft (Germany), and the Instituto Geografico Nacional (Spain).

  8. THE TIP OF THE RED GIANT BRANCH DISTANCES TO TYPE Ia SUPERNOVA HOST GALAXIES. II. M66 AND M96 IN THE LEO I GROUP

    SciTech Connect

    Lee, Myung Gyoon; Jang, In Sung E-mail: isjang@astro.snu.ac.kr

    2013-08-10

    M66 and M96 in the Leo I Group are nearby spiral galaxies hosting Type Ia supernovae (SNe Ia). We estimate the distances to these galaxies from the luminosity of the tip of the red giant branch (TRGB). We obtain VI photometry of resolved stars in these galaxies from F555W and F814W images in the Hubble Space Telescope archive. From the luminosity function of these red giants, we find the TRGB I-band magnitude to be I{sub TRGB} = 26.20 {+-} 0.03 for M66 and 26.21 {+-} 0.03 for M96. These values yield distance modulus (m - M){sub 0} = 30.12 {+-} 0.03(random) {+-} 0.12(systematic) for M66 and (m - M){sub 0} = 30.15 {+-} 0.03(random) {+-} 0.12(systematic) for M96. These results show that they are indeed the members of the same group. With these results we derive absolute maximum magnitudes of two SNe (SN 1989B in M66 and SN 1998bu in M96). V-band magnitudes of these SNe Ia are {approx}0.2 mag fainter than SN 2011fe in M101, one of the nearest recent SNe Ia. We also derive near-infrared magnitudes for SN 1998bu. Optical magnitudes of three SNe Ia (SN 1989B, SN 1998bu, and SN 2011fe) based on TRGB analysis yield a Hubble constant, H{sub 0} = 68.4 {+-} 2.6(random) {+-} 3.7(systematic) km s{sup -1} Mpc{sup -1}. This value is similar to the values derived from recent WMAP9 results, H{sub 0} = 69.32 {+-} 0.80 km s{sup -1} Mpc{sup -1}, and from Planck results, H{sub 0} = 67.3 {+-} 1.2 km s{sup -1} Mpc{sup -1}, but smaller than other recent determinations based on Cepheid calibration for SNe Ia luminosity, H{sub 0} = 74 {+-} 3 km s{sup -1} Mpc{sup -1}.

  9. The Most Luminous Heavily Obscured Quasars Have a High Merger Fraction: Morphological Study of WISE-selected Hot Dust-obscured Galaxies

    NASA Astrophysics Data System (ADS)

    Fan, Lulu; Han, Yunkun; Fang, Guanwen; Gao, Ying; Zhang, Dandan; Jiang, Xiaoming; Wu, Qiaoqian; Yang, Jun; Li, Zhao

    2016-05-01

    Previous studies have shown that Wide-field Infrared Survey Explorer-selected hyperluminous, hot dust-obscured galaxies (Hot DOGs) are powered by highly dust-obscured, possibly Compton-thick active galactic nuclei (AGNs). High obscuration provides us a good chance to study the host morphology of the most luminous AGNs directly. We analyze the host morphology of 18 Hot DOGs at z ˜ 3 using Hubble Space Telescope/WFC3 imaging. We find that Hot DOGs have a high merger fraction (62 ± 14%). By fitting the surface brightness profiles, we find that the distribution of Sérsic indices in our Hot DOG sample peaks around 2, which suggests that most Hot DOGs have transforming morphologies. We also derive the AGN bolometric luminosity (˜1014 L ⊙) of our Hot DOG sample by using IR spectral energy distributions decomposition. The derived merger fraction and AGN bolometric luminosity relation is well consistent with the variability-based model prediction. Both the high merger fraction in an IR-luminous AGN sample and relatively low merger fraction in a UV/optical-selected, unobscured AGN sample can be expected in the merger-driven evolutionary model. Finally, we conclude that Hot DOGs are merger-driven and may represent a transit phase during the evolution of massive galaxies, transforming from the dusty starburst-dominated phase to the unobscured QSO phase.

  10. Ultraviolet Broad Absorption Features and the Spectral Energy Distribution of the QSO PG 1351+641. 2.5

    NASA Technical Reports Server (NTRS)

    Zheng, W.; Kriss, G. A.; Wang, J. X.; Brotherton, M.; Oegerle, W. R.; Blair, W. P.; Davidsen, A. F.; Green, R. F.; Hutchings, J. B.; Kaiser, M. E.; Fisher, Richard R. (Technical Monitor)

    2001-01-01

    We present a moderate-resolution (approximately 20 km/s) spectrum of the broad-absorption line QSO PG 1351+64 between 915-1180 angstroms, obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE). Additional low-resolution spectra at longer wavelengths were also obtained with the Hubble Space Telescope (HST) and ground-based telescopes. Broad absorption is present on the blue wings of C III lambda977, Ly-beta, O VI lambda-lambda-1032,1038, Ly-alpha, N V lambda-lambda-1238,1242, Si IV lambda-lambda-1393,1402, and C IV lambda-lambda-1548,1450. The absorption profile can be fitted with five components at velocities of approximately -780, -1049, -1629, -1833, and -3054 km/s with respect to the emission-line redshift of z = 0.088. All the absorption components cover a large fraction of the continuum source as well as the broad-line region. The O VI emission feature is very weak, and the O VI/Ly-alpha flux ratio is 0.08, one of the lowest among low-redshift active galaxies and QSOs. The ultraviolet continuum shows a significant change in slope near 1050 angstroms in the restframe. The steeper continuum shortward of the Lyman limit extrapolates well to the observed weak X-ray flux level. The absorbers' properties are similar to those of high-redshift broad absorption-line QSOs. The derived total column density of the UV absorbers is on the order of 10(exp 21)/s, unlikely to produce significant opacity above 1 keV in the X-ray. Unless there is a separate, high-ionization X-ray absorber, the QSO's weak X-ray flux may be intrinsic. The ionization level of the absorbing components is comparable to that anticipated in the broad-line region, therefore the absorbers may be related to broad-line clouds along the line of sight.

  11. Ultraviolet Broad Absorption Features and the Spectral Energy Distribution of the QSO PG 1351+64. 3.1

    NASA Technical Reports Server (NTRS)

    Zheng, W.; Kriss, G. A.; Wang, J. X.; Brotherton, M.; Oegerle, W. R.; Blair, W. P.; Davidsen, A. F.; Green, R. F.; Hutchings, J. B.; Kaiser, M. E.; Fisher, R. (Technical Monitor)

    2001-01-01

    We present a moderate-resolution (approximately 20 km s(exp -1) spectrum of the mini broad absorption line QSO PG 1351+64 between 915-1180 A, obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE). Additional low-resolution spectra at longer wavelengths were also obtained with the Hubble Space Telescope (HST) and ground-based telescopes. Broad absorption is present on the blue wings of C III (lambda)977, Ly(beta), O VI (lambda)(lambda)1032,1038, Ly(alpha), N V (lambda)(lambda)1238,1242, Si IV (lambda)(lambda)1393,1402, and C IV (lambda)(lambda)1548,1450. The absorption profile can be fitted with five components at velocities of approximately -780, -1049, -1629, -1833, and -3054 km s(exp -1) with respect to the emission-line redshift of z = 0.088. All the absorption components cover a large fraction of the continuum source as well as the broad-line region. The O VI emission feature is very weak, and the O VI/Ly(alpha) flux ratio is 0.08, one of the lowest among low-redshift active galaxies and QSOs. The UV (ultraviolet) continuum shows a significant change in slope near 1050 A in the restframe. The steeper continuum shortward of the Lyman limit extrapolates well to the observed weak X-ray flux level. The absorbers' properties are similar to those of high-redshift broad absorption-line QSOs. The derived total column density of the UV absorbers is on the order of 10(exp 21) cm(exp -2), unlikely to produce significant opacity above 1 keV in the X-ray. Unless there is a separate, high-ionization X-ray absorber, the QSO's weak X-ray flux may be intrinsic. The ionization level of the absorbing components is comparable to that anticipated in the broad-line region, therefore the absorbers may be related to broad-line clouds along the line of sight.

  12. The Host Galaxies of X-Ray Selected Active Galactic Nuclei to z - 2.5: Structure, Star-Formation and Their Relationships from CANDELS and Herschel/Pacs

    NASA Technical Reports Server (NTRS)

    Rosario, D.J.; McIntosh, D. H.; van der Wel, A.; Kartaltepe, J.; Lang, P.; Santini, P.; Wuyts, S.; Lutz, D.; Rafelski, M.; Villforth, C.; Alexander, D. M.; Bauer, F. E.; Bell, E. F.; Berta, S.; Brandt, W. N.; Conselice, C. J.; Dekel, A.; Faber, S. M.; Ferguson, H. C.; Genzel, R.; Grogin, N. A.; Kocevski, D. D.; Koekemoer, A. M.; Koo, D. C.; Straughn, A.

    2014-01-01

    We study the relationship between the structure and star-formation rate (SFR) of X-ray selected low and moderate luminosity active galactic nuclei (AGNs) in the two Chandra Deep Fields, using Hubble Space Telescope imaging from the Cosmic Assembly Near Infrared Extragalactic Legacy Survey (CANDELS) and deep far-infrared maps from the PEP+GOODS-Herschel survey. We derive detailed distributions of structural parameters and FIR luminosities from carefully constructed control samples of galaxies, which we then compare to those of the AGNs. At z is approximately 1, AGNs show slightly diskier light profiles than massive inactive (non-AGN) galaxies, as well as modestly higher levels of gross galaxy disturbance (as measured by visual signatures of interactions and clumpy structure). In contrast, at z 2, AGNs show similar levels of galaxy disturbance as inactive galaxies, but display a red central light enhancement, which may arise due to a more pronounced bulge in AGN hosts or due to extinguished nuclear light. We undertake a number of tests of both these alternatives, but our results do not strongly favour one interpretation over the other. The mean SFR and its distribution among AGNs and inactive galaxies are similar at z greater than 1.5. At z less than 1, however, clear and significant enhancements are seen in the SFRs of AGNs with bulge-dominated light profiles. These trends suggest an evolution in the relation between nuclear activity and host properties with redshift towards a minor role for mergers and interactions at z greater than 15

  13. Supplement: “Going the Distance: Mapping Host Galaxies of LIGO and Virgo Sources in Three Dimensions Using Local Cosmography and Targeted Follow-up” (2016, ApJL, 829, L15)

    NASA Astrophysics Data System (ADS)

    Singer, Leo P.; Chen, Hsin-Yu; Holz, Daniel E.; Farr, Will M.; Price, Larry R.; Raymond, Vivien; Cenko, S. Bradley; Gehrels, Neil; Cannizzo, John; Kasliwal, Mansi M.; Nissanke, Samaya; Coughlin, Michael; Farr, Ben; Urban, Alex L.; Vitale, Salvatore; Veitch, John; Graff, Philip; Berry, Christopher P. L.; Mohapatra, Satya; Mandel, Ilya

    2016-09-01

    This is a supplement to the Letter of Singer et al., in which we demonstrated a rapid algorithm for obtaining joint 3D estimates of sky location and luminosity distance from observations of binary neutron star mergers with Advanced LIGO and Virgo. We argued that combining the reconstructed volumes with positions and redshifts of possible host galaxies can provide large-aperture but small field of view instruments with a manageable list of targets to search for optical or infrared emission. In this Supplement, we document the new HEALPix-based file format for 3D localizations of gravitational-wave transients. We include Python sample code to show the reader how to perform simple manipulations of the 3D sky maps and extract ranked lists of likely host galaxies. Finally, we include mathematical details of the rapid volume reconstruction algorithm.

  14. Starburst models of merging galaxies

    NASA Technical Reports Server (NTRS)

    Prestwich, Andrea H.

    1993-01-01

    In the past decade, infrared observations have shown that interacting and merging galaxies have higher luminosities than isolated systems, with the luminosities in mergers as high as 10(exp 12) solar luminosity. However, the origin of the luminosity found in mergers is controversial, with two main competing theories. The first is the starburst scenario. As two gas rich galaxies start to merge, cloud-cloud collisions induce fast shocks in the molecular gas. This gas cools, collapses, and fragments, producing a blast of star formation. The main rival to this theory is that the infrared luminosity is produced by a dust embedded active nucleus, the merger of two gas rich galaxies providing the 'fuel to feed the monster'. There has even been speculation that there is an evolutionary link between starbursts and active nuclei, and that possibly active galactic nuclei (AGN's) and QSO's were formed from a starburst. Assuming that the infrared luminosity in merging galaxies is due to star formation, there should be ionizing photons produced from the high mass stars, giving rise to recombination line emission. The objective is to use a simple starburst model to test the hypothesis that the extreme infrared luminosity of merging galaxies is due to a starburst.

  15. Gamma-Ray Burst Afterglows as Probes of Environment and Blastwave Physics. 1; Absorption by Host Galaxy Gas and Dust

    NASA Technical Reports Server (NTRS)

    Starling, R. L. C.; Wijers, R. A. M. J.; Wiersema, K.; Rol, E.; Curran, P. A.; Kouveliotou, C.; vanderHorst, A. J.; Heemskerk, M. H. M.

    2006-01-01

    We use a new approach to obtain limits on the absorbing columns towards an initial sample of 10 long Gamma-Ray Bursts observed with BeppoSAX and selected on the basis of their good optical and nIR coverage, from simultaneous fits to nIR, optical and X-ray afterglow data, in count space and including the effects of metallicity. In no cases is a MIV-like ext,inction preferred, when testing MW, LMC and SMC extinction laws. The 2175A bump would in principle be detectable in all these afterglows, but is not present in the data. An SMC-like gas-to-dust ratio or lower value can be ruled out for 4 of the hosts analysed here (assuming Sh4C metallicity and extinction law) whilst the remainder of the sample have too large an error to discriminate. We provide a more accurate estimate of the line-of-sight extinction and improve upon the uncertainties for the majority of the extinction measurements made in previous studies of this sample. We discuss this method to determine extinction values in comparison with the most commonly employed existing methods.

  16. The z = 1.6748 C I Absorber Toward the QSO PKS 1756+237

    NASA Astrophysics Data System (ADS)

    Roth, Katherine C.; Bauer, James M.; Jim, Kevin T. C.

    We have detected C I ground-state absorption at zabs = 1.6748 toward the QSO PKS 1756+237 (zem = 1.725), making this only the fourth known C I QSO absorber. The absence of excited-state fine-structure C I lines is compatible with the redshifted Cosmic Microwave Background Radiation at an expected temperature of TCMBR (1+z) = 7.291 K (Mather et al. 1994, ApJ, 354, L37). We find a 2 σ upper-limit on the C I excitation temperature of Tex <= 7.73(+0.53, -0.46) K (Roth & Bauer 1999, ApJ, submitted). Our Keck HIRES spectra (8.3 km s-1 FWHM) obtained in May 1997 also reveal the existence of Ni II and Fe II lines with a sub-solar Ni/Fe abundance ratio, presumably indicative of dust. We have obtained deep, high resolution (0.3'' FWHM) images in H+K' with the UH 2.2m Tip-Tilt system of the QSO field in order to identify the system responsible for the zabs = 1.6748 absorption. We detect two faint candidate systems within 1.5'' and 3'' (≅ 15 and 30 kpc, Hcirc = 65) of the QSO.

  17. A NIR Flare of the QSO [HB89] 0234+285

    NASA Astrophysics Data System (ADS)

    Carrasco, L.; Porras, A.; Recillas, E.; Chavushyan, V.; Mayya, D. Y.

    2017-02-01

    We report on the recent NIR flare of the high redshift QSO (z=1.213) [hb89]0234+285 also known as BZQJ0237+2848, cross correlated with the radio source 4C+28.07 and the Gamma-ray source 2FGLJ0237.4+2846.

  18. Evidence for the presence of dust in intervening QSO absorbers from the Sloan Digital Sky Survey

    NASA Astrophysics Data System (ADS)

    Khare, P.; York, D. G.; vanden Berk, D.; Kulkarni, V. P.; Crotts, A. P. S.; Welty, D. E.; Lauroesch, J. T.; Richards, G. T.; Alsayyad, Y.; Kumar, A.; Lundgren, B.; Shanidze, N.; Vanlandingham, J.; Baugher, B.; Hall, P. B.; Jenkins, E. B.; Menard, B.; Rao, S.; Turnshek, D.; Yip, C. W.

    2005-03-01

    We find evidence for dust in the intervening QSO absorbers from the spectra of QSOs in the Sloan Digital Sky Survey Data Release 1. No evidence is found for the 2175 Å feature which is present in the Milky Way dust extinction curve.

  19. Infrared flaring of the potential gamma-ray source QSO B0133+47

    NASA Astrophysics Data System (ADS)

    Carramiñana, A.; Carrasco, L.; Recillas, E.; Chavushyan, V.

    2008-12-01

    We call attention on our recent observations of QSO B0133+47 with the Cananea NIR camera (CANICA) on the 2.1m telescope at the Observatorio Astrofísico Guillermo Haro. We found this quasar to show fluxes 2.5 magnitudes brighter than 2MASS values, of epoch 1999, but undergoing a rapid decline.

  20. Karl G. Jansky very large array observations of cold dust and molecular gas in starbursting quasar host galaxies at z ∼ 4.5

    SciTech Connect

    Wagg, J.; Carilli, C. L.; Lentati, L.; Maiolino, R.; Hills, R.; Aravena, M.; Cox, P.; McMahon, R. G.; Riechers, D.; Walter, F.; Andreani, P.; Wolfe, A.

    2014-03-10

    We present Karl G. Jansky Very Large Array (VLA) observations of 44 GHz continuum and CO J = 2-1 line emission in BRI 1202–0725 at z = 4.7 (a starburst galaxy and quasar pair) and BRI 1335–0417 at z = 4.4 (also hosting a quasar). With the full 8 GHz bandwidth capabilities of the upgraded VLA, we study the (rest-frame) 250 GHz thermal dust continuum emission for the first time along with the cold molecular gas traced by the low-J CO line emission. The measured CO J = 2-1 line luminosities of BRI 1202–0725 are L{sub CO}{sup ′}=(8.7±0.8)×10{sup 10} K km s{sup –1} pc{sup 2} and L{sub CO}{sup ′}=(6.0 ± 0.5)×10{sup 10} K km s{sup –1} pc{sup 2} for the submillimeter galaxy (SMG) and quasar, respectively, which are equal to previous measurements of the CO J = 5-4 line luminosities implying thermalized line emission, and we estimate a combined cold molecular gas mass of ∼9×10{sup 10} M {sub ☉}. In BRI 1335–0417 we measure L{sub CO}{sup ′}=(7.3±0.6)×10{sup 10} K km s{sup –1} pc{sup 2}. We detect continuum emission in the SMG BRI 1202–0725 North (S {sub 44} {sub GHz} = 51 ± 6 μJy), while the quasar is detected with S {sub 44} {sub GHz} = 24 ± 6 μJy and in BRI 1335–0417 we measure S {sub 44} {sub GHz} = 40 ± 7 μJy. Combining our continuum observations with previous data at (rest-frame) far-infrared and centimeter wavelengths, we fit three-component models in order to estimate the star formation rates. This spectral energy distribution fitting suggests that the dominant contribution to the observed 44 GHz continuum is thermal dust emission, while either thermal free-free or synchrotron emission contributes less than 30%.

  1. Terminal Velocity Infall in QSO Absorption Line Halos

    NASA Astrophysics Data System (ADS)

    Benjamin, Robert A.

    We explore the hypothesis that clouds detected in quasar absorption line systems are falling at a terminal velocity toward the center of high redshift gaseous galactic halos. Since both the ionization level and terminal velocity of halo clouds increase with increasing distance from the central galaxy, velocity resolved profiles of highly ionized gas are predicted to have a greater width than low ionization gas. A line of sight passing through the center of gaseous halo (an idealized damped Ly alpha system), yields low ionization absorption at the velocity of the galaxy, flanked by high ionization on either side. Reasonable halo parameters yield total velocity extents for C IV of Delta v_{C IV}=100-200 km s^{-1}, in agreement with many systems observed by Lu et al (1997). The remaining systems may better described by the rotating disk model of Prochaska & Wolfe (1998). Finally, observational tests are suggested for verifying or falsifying the terminal velocity hypothesis for these systems.

  2. The time delay in the twin QSO Q0957 + 561

    SciTech Connect

    Schild, R.E. )

    1990-12-01

    From 10 yr of brightness monitoring of the two gravitational mirage components of Q0957 + 561 A,B it is shown that the time delay is 1.11 yr. An intensive program of daily brightness monitoring suggests a further refinement of the time delay to 404 days. Careful superposition of the phased brightness records shows that small differences are seen. These differences are attributed to microlensing by a star or stars in the lens galaxy. 5 refs.

  3. METALLICITIES, DUST, AND MOLECULAR CONTENT OF A QSO-DAMPED Ly{alpha} SYSTEM REACHING log N(H I) = 22: AN ANALOG TO GRB-DLAs

    SciTech Connect

    Guimaraes, R.; Noterdaeme, P.; Petitjean, P.; Ledoux, C.; Srianand, R.; Rahmani, H.; Lopez, S.

    2012-06-15

    We present the elemental abundance and H{sub 2} content measurements of a damped Ly{alpha} (DLA) system with an extremely large H I column density, log N(H I) (cm{sup -2}) = 22.0 {+-} 0.10, at z{sub abs} = 3.287 toward the QSO SDSS J081634+144612. We measure column densities of H{sub 2}, C I, C I*, Zn II, Fe II, Cr II, Ni II, and Si II from a high signal-to-noise and high spectral resolution VLT-UVES spectrum. The overall metallicity of the system is [Zn/H] = -1.10 {+-} 0.10 relative to solar. Two molecular hydrogen absorption components are seen at z = 3.28667 and 3.28742 (a velocity separation of Almost-Equal-To 52 km s{sup -1}) in rotational levels up to J = 3. We derive a total H{sub 2} column density of log N(H{sub 2}) (cm{sup -2}) = 18.66 and a mean molecular fraction of f = 2N(H{sub 2})/[2N(H{sub 2}) + N(H I)] = 10{sup -3.04{+-}0.37}, typical of known H{sub 2}-bearing DLA systems. From the observed abundance ratios we conclude that dust is present in the interstellar medium of this galaxy, with an enhanced abundance in the H{sub 2}-bearing clouds. However, the total amount of dust along the line of sight is not large and does not produce any significant reddening of the background QSO. The physical conditions in the H{sub 2}-bearing clouds are constrained directly from the column densities of H{sub 2} in different rotational levels, C I and C I*. The kinetic temperature is found to be T Almost-Equal-To 75 K and the particle density lies in the range n{sub H} = 50-80 cm{sup -3}. The neutral hydrogen column density of this DLA is similar to the mean H I column density of DLAs observed at the redshift of {gamma}-ray bursts (GRBs). We explore the relationship between GRB-DLAs and the high column density end of QSO-DLAs finding that the properties (metallicity and depletion) of DLAs with log N(H I) > 21.5 in the two populations do not appear to be significantly different.

  4. Matching Supernovae to Galaxies

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-12-01

    One of the major challenges for modern supernova surveys is identifying the galaxy that hosted each explosion. Is there an accurate and efficient way to do this that avoids investing significant human resources?Why Identify Hosts?One problem in host galaxy identification. Here, the supernova lies between two galaxies but though the centroid of the galaxy on the right is closer in angular separation, this may be a distant background galaxy that is not actually near the supernova. [Gupta et al. 2016]Supernovae are a critical tool for making cosmological predictions that help us to understand our universe. But supernova cosmology relies on accurately identifying the properties of the supernovae including their redshifts. Since spectroscopic followup of supernova detections often isnt possible, we rely on observations of the supernova host galaxies to obtain redshifts.But how do we identify which galaxy hosted a supernova? This seems like a simple problem, but there are many complicating factors a seemingly nearby galaxy could be a distant background galaxy, for instance, or a supernovas host could be too faint to spot.The authors algorithm takes into account confusion, a measure of how likely the supernova is to be mismatched. In these illustrations of low (left) and high (right) confusion, the supernova is represented by a blue star, and the green circles represent possible host galaxies. [Gupta et al. 2016]Turning to AutomationBefore the era of large supernovae surveys, searching for host galaxies was done primarily by visual inspection. But current projects like the Dark Energy Surveys Supernova Program is finding supernovae by the thousands, and the upcoming Large Synoptic Survey Telescope will likely discover hundreds of thousands. Visual inspection will not be possible in the face of this volume of data so an accurate and efficient automated method is clearly needed!To this end, a team of scientists led by Ravi Gupta (Argonne National Laboratory) has recently

  5. Dark Galaxies and Lost Baryons (IAU S244)

    NASA Astrophysics Data System (ADS)

    Davies, Jonathan I.; Disney, Michael J.

    2008-05-01

    Preface; Conference prelims; The HI that barked in the night M. J. Disney; The detection of dark galaxies in blind HI surveys J. I. Davies; Red haloes of galaxies - reservoirs of baryonic dark matter? E. Zackrisson, N. Bergvall, C. Flynn, G. Ostlin, G. Micheva and B. Baldwell; Constraints on dark and visible mass in galaxies from strong gravitational lensing S. Dye and S. Warren; Lost baryons at low redshift S. Mathur, F. Nicastro and R. Williams; Observed properties of dark matter on small spatial scales R. Wyse and G. Gilmore; The mass distribution in spiral galaxies P. Salucci; Connecting lost baryons and dark galaxies via QSO absorption lines T. Tripp; ALFALFA: HI cosmology in the local universe R. Giovanelli; The ALFALFA search for (almost) dark galaxies across the HI mass function M. Haynes; HI clouds detected towards Virgo with the Arecibo Legacy Fast ALFA Survey B. Kent; Cosmic variance in the HI mass function S. Schneider; The Arecibo Galaxy Environments Survey - potential for finding dark galaxies and results so far R. Minchin et al.; Free-floating HI clouds in the M81 group E. Brinks, F. Walter and E. Skillman; Where are the stars in dark galaxies J. Rosenberg, J. Salzer and J. Cannon; The halo by halo missing baryon problem S. McGaugh; The local void is really empty R. Tully; Voids in the local volume: a limit on appearance of a galaxy in a dark matter halo A. Tikhonov and A. Klypin; Dim baryons in the cosmic web C. Impey; A census of baryons in galaxy clusters and groups A. Gonzalez, D. Zaritsky and A. Zabludo; Statistical properties of the intercluster light from SDSS image stacking S. Zibetti; QSO strong gravitational lensing and the detection of dark halos A. Maccio; Strong gravitational lensing: bright galaxies and lost dark-matter L. Koopmans; Mapping the distribution of luminous and dark matter in strong lensing galaxies I. Ferreras, P. Saha, L. Williams and S. Burles; Tidal debris posing as dark galaxies P. Duc, F. Bournaud and E. Brinks

  6. Interstellar Abundances in the SMC - Implications for QSO - Line Systems and for Chem EV of Universe-Cyc 4 Med Early Acq for 5608

    NASA Astrophysics Data System (ADS)

    Welty, Daniel

    1994-01-01

    We propose a detailed study of the interstellar (IS) abundances and depletions for one line of sight in the SMC - a nearby low metallicity, low dust-to-gas ratio system where stellar abundance data are also available. We will use the GHRS ECH-B to obtain absorption-line profiles of Zn II, Cr II, Si II, Fe II, Mn II, Mg II, and Al III, to determine both the detailed component structures and the relative abundances of those species in the various components. We will use the derived component structures to obtain similarly detailed abundances for S II, Ni II, and Al II from existing lower resolution short-wavelength IUE spectra (in which severe blending of components has to now prevented accurate abundance determinations). In addition to the intrinsic interest in obtaining detailed IS abundance and depletion data for an external galaxy quite different from our own, such data are needed for interpreting the abundance patterns found in QSO absorption-line systems. A number of the QSOALS examined to date seem to exhibit overall metallicities of about 0.1 x Solar, with some additional depletion of refractory elements. If the pattern of that depletion can be constrained, then the build-up of many elements can be traced, via the QSOALS, from redshifts 3.5 to 0.5 - with significant implications for the formation and evolution of galaxies.

  7. Variability of the broad absorption lines in the QSO UM 232

    NASA Technical Reports Server (NTRS)

    Barlow, Thomas A.; Junkkarinen, Vesa T.; Burbidge, E. Margaret

    1989-01-01

    Low-resolution spectra of UM 232 taken in 1978, 1979, and 1988 at Lick Observatory are presented. Large changes in the Si IV lambda 1397, CIV lambda 1549, and Al III lambda 1857 broad absorption lines are apparent. The decrease in column density in all three ions and an observed brightening of the QSO suggests that these changes are due to an increase in the ionization level driven by an increase in the central source luminosity. This mechanism has been proposed by Smith and Penston to explain small changes in the absorption spectrum of the QSO 1246-057. The spectra of UM 232 show that the fractional decrease in optical depth is smaller at higher outflow velocies. The structure of the broad absorption-line region (BALR) is investigted by estimating an ionization parameter for each ion species as a function of velocity.

  8. Intervening Metal Systems in GRB and QSO Sight Lines: The Mg II and C IV Question

    NASA Astrophysics Data System (ADS)

    Sudilovsky, Vladimir; Savaglio, Sandra; Vreeswijk, Paul; Ledoux, Cédric; Smette, Alain; Greiner, Jochen

    2007-11-01

    Prochter and coworkers recently found that the number density of strong intervening 0.5QSO spectra. We have conducted a similar study using C IV absorbers. Our C IV sample, consisting of a total of 19 systems, is drawn from three high-resolution and high to moderate signal-to-noise ratio VLT UVES spectra of three long-duration GRB afterglows, covering the redshift interval 1.6QSO spectra. We discuss several possibilities for the discrepancy between C IV and Mg II absorbers and conclude that a higher dust extinction in the Mg II QSO samples studied up to now would give the most straightforward solution. However, this effect is only important for the strong Mg II absorbers. Regardless of the reasons for this discrepancy, this result confirms once more that GRBs can be used to detect a side of the universe that was unknown before, not necessarily connected with GRBs themselves, providing an alternative and fundamental investigative tool of the cosmic evolution of the universe. Based on observations collected at the European Southern Observatory, Chile; proposals 75.A-0385, 75.A-0603, and 77.D-0661.

  9. Galaxies with Strong Nitrogen Lines

    NASA Astrophysics Data System (ADS)

    Bergmann, T. S.; Pastoriza, M. G.

    1987-05-01

    ABSTRACT. From a qualitative spectroscopic survey of southern galaxies made by Pastoriza, a group with different morphological types whose nuclear region showed particular strong emission [N II]A6548-6584 lines when compared to Hn, was selected in order to investigate why [N II] is so strong. This work presents the results of a first analysis of the spectra of some of the galaxies above obtained with the 1-m telescope plus 2DFRUTTI detector of the Cerro Tololo Inter-American Observatory. The spectra are all very similar showing strong stellar continuum and absorption lines, and all the emission spectra show [0111] >[OII], [NIl] > H . None of the spectra show H in emission. Using the relative intensities of the H and K Call lines (Talent 1982, PLtb. A.S.P., 94,36), the obtained integrated spectra for all the observed galaxies is later than GO, which means that the H absorption lines should not be strong. From the relative intensities of the emission lines, we conclude that these galaxies cannot be classified as Starburst or LINERS. They are similar to Seyfert 2 (Osterbrock 1986, Act#va QSO4, preprint), but the FWHM of the lines is less than 300 km s . Also Ol X6300 is not clearly seen, and the absorption spectrum is strong relative to the emission spectrum. The preliminary conclusion is an activity similar but milder than that present in Seyfert 2 galaxies, as sug gested by Rose and Searle (1982, Ap. 5., 253, 556) and Rose and Cecil (1983, Ap. 5., 266, 531) for the nucleus of M51, maybe affected by an anomalous nitrogen abundance. K o : GALAXIES-ACTIVE - SPECTROSCOPY

  10. NE VIII lambda 774 and time variable associated absorption in the QSO UM 675

    NASA Technical Reports Server (NTRS)

    Hamann, Fred; Barlow, Thomas A.; Beaver, E. A.; Burbidge, E. M.; Cohen, Ross D.; Junkkarinen, Vesa; Lyons, R.

    1995-01-01

    We discuss measurements of Ne VIII lambda 774 absorption and the time variability of other lines in the z(sub a) approximately equal z(sub e) absorption system of the z(sub e) = 2.15 QSO UM 675 (0150-203). The C IV lambda 1549 and N V 1240 doublets at z(sub a) = 2.1340 (shifted approximately 1500 km/s from z(sub e) strengthened by a factor of approximately 3 between observations by Sargent, Boksenberg and Steidel (1981 November) and our earliest measurements (1990 November and December). We have no information on changes in other z(sub a) approximately equal z(sub e) absorption lines. Continued monitoring since 1990 November shows no clear changes in any of the absorptions between approximately 1100 and 1640 A rest. The short timescale of the variability (less than or approximately equal to 2.9 yr rest) strongly suggests that the clouds are dense, compact, close to the QSO, and photoionized by the QSO continuum. If the line variability is caused by changes in the ionization, the timescale requires densities greater than approximately 4000/cu cm. Photoionization calculations place the absorbing clouds within approximately 200 pc of the continuum source. The full range of line ionizations (from Ne VIII lambda 774 to C III lambda 977) in optically thin gas (no Lyman limit) implies that the absorbing regions span a factor of more than approximately 10 in distance or approximately 100 in density. Across these regions, the total hydrogen (H I + H II) column ranges from a few times 10(exp 18)/sq cm in the low-ionization gas to approximately 10(exp 20)/sq cm where the Ne VIII doublet forms. The metallicity is roughly solar or higher, with nitrogen possibly more enhanced by factors of a few. The clouds might contribute significant line emission if they nearly envelop the QSO. The presence of highly ionized Ne VIII lambda 774 absorption near the QSO supports recent studies that link z(sub a) approximately equal to z(sub e) systems with X-ray 'wamr absorbers. We show that the

  11. NE VIII lambda 774 and time variable associated absorption in the QSO UM 675

    NASA Astrophysics Data System (ADS)

    Hamann, Fred; Barlow, Thomas A.; Beaver, E. A.; Burbidge, E. M.; Cohen, Ross D.; Junkkarinen, Vesa; Lyons, R.

    1995-04-01

    We discuss measurements of Ne VIII lambda 774 absorption and the time variability of other lines in the za approximately equal ze absorption system of the ze = 2.15 QSO UM 675 (0150-203). The C IV lambda 1549 and N V 1240 doublets at za = 2.1340 (shifted approximately 1500 km/s from ze strengthened by a factor of approximately 3 between observations by Sargent, Boksenberg and Steidel (1981 November) and our earliest measurements (1990 November and December). We have no information on changes in other za approximately equal ze absorption lines. Continued monitoring since 1990 November shows no clear changes in any of the absorptions between approximately 1100 and 1640 A rest. The short timescale of the variability (less than or approximately equal to 2.9 yr rest) strongly suggests that the clouds are dense, compact, close to the QSO, and photoionized by the QSO continuum. If the line variability is caused by changes in the ionization, the timescale requires densities greater than approximately 4000/cu cm. Photoionization calculations place the absorbing clouds within approximately 200 pc of the continuum source. The full range of line ionizations (from Ne VIII lambda 774 to C III lambda 977) in optically thin gas (no Lyman limit) implies that the absorbing regions span a factor of more than approximately 10 in distance or approximately 100 in density. Across these regions, the total hydrogen (H I + H II) column ranges from a few times 1018/sq cm in the low-ionization gas to approximately 1020/sq cm where the Ne VIII doublet forms. The metallicity is roughly solar or higher, with nitrogen possibly more enhanced by factors of a few. The clouds might contribute significant line emission if they nearly envelop the QSO. The presence of highly ionized Ne VIII lambda 774 absorption near the QSO supports recent studies that link za approximately equal to ze systems with X-ray 'wamr absorbers. We show that the Ne VIII absorbing gas would itself produce measurable warm

  12. Evolution of galaxy habitability

    NASA Astrophysics Data System (ADS)

    Gobat, R.; Hong, S. E.

    2016-08-01

    We combine a semi-analytic model of galaxy evolution with constraints on circumstellar habitable zones and the distribution of terrestrial planets in order to probe the suitability of galaxies of different mass and type to host habitable planets, and how it evolves with time. We find that the fraction of stars with terrestrial planets in their habitable zone (known as habitability) depends only weakly on galaxy mass, with a maximum around 4 × 1010M⊙. We estimate that 0.7% of all stars in Milky Way-type galaxies to host a terrestrial planet within their habitable zone, consistent with the value derived from Kepler observations. On the other hand, the habitability of passive galaxies is slightly but systematically higher, unless we assume an unrealistically high sensitivity of planets to supernovae. We find that the overall habitability of galaxies has not changed significantly in the last ~8 Gyr, with most of the habitable planets in local disk galaxies having formed ~1.5 Gyr before our own solar system. Finally, we expect that ~1.4 ×109 planets similar to present-day Earth have existed so far in our galaxy.

  13. Explore Full Range of QSO/AGN Properties

    NASA Technical Reports Server (NTRS)

    Oliversen, Ronald (Technical Monitor); Wilkes, Belinda

    2005-01-01

    The goal of the proposal is to perform ISO spectroscopic studies, including data analysis and modeling, of star formation regions using an ensemble of archival space-based data from the Infrared Space Observatory s Long Wavelength Spectrometer and Short Wavelength Spectrometer, but including as well some other spectroscopic databases. Four kinds of regions are considered in the studies: (1) disks around more evolved objects; (2) young, low or high mass pre-main sequence stars in star formation regions; (3) star formation in external, bright IR galaxies; and (4) the galactic center. One prime focus of the program is the OH lines in the far infrared. The program had the following goals: 1) Refine the data analysis of IS0 observations to obtain deeper and better SNR results on selected sources. The IS0 data itself underwent "pipeline 10" reductions in early 2001, and additional "hands-on data reduction packages" were supplied by the IS0 teams in 2001. The Fabry-Perot database is particularly sensitive to noise and slight calibration errors. 2) Model the atomic and molecular line shapes, in particular the OH lines, using revised monte- carlo techniques developed by the SWAS team at the Center for Astrophysics; 3) Attend scientific meetings and workshops; 4) Do E&PO activities related to infrared astrophysics and/or spectroscopy.

  14. Radio Galaxies.

    ERIC Educational Resources Information Center

    Downes, Ann

    1986-01-01

    Provides background information on radio galaxies. Topic areas addressed include: what produces the radio emission; radio telescopes; locating radio galaxies; how distances to radio galaxies are found; physics of radio galaxies; computer simulations of radio galaxies; and the evolution of radio galaxies with cosmic time. (JN)

  15. The Tip of the Red Giant Branch Distances to Typa Ia Supernova Host Galaxies. V. NGC 3021, NGC 3370, and NGC 1309 and the Value of the Hubble Constant

    NASA Astrophysics Data System (ADS)

    Jang, In Sung; Lee, Myung Gyoon

    2017-02-01

    We present final results of a program for the determination of the Hubble constant based on the calibration of the Type Ia supernovae (SNe Ia) using the Tip of the Red Giant Branch (TRGB). We report TRGB distances to three SN Ia host galaxies, NGC 3021, NGC 3370, and NGC 1309. We obtain F555W and F814W photometry of resolved stars from the archival Hubble Space Telescope data. Luminosity functions of red giant stars in the outer regions of these galaxies show the TRGB to be at F814W ≈ QT = 28.2 ∼ 28.5 mag. From these TRGB magnitudes and the revised TRGB calibration based on two distance anchors (NGC 4258 and the LMC) in Jang & Lee (2017; Paper IV), we derive the distances: {(m-M)}0=32.178+/- 0.033 for NGC 3021, 32.253 ± 0.041 for NGC 3370, and 32.471 ± 0.040 for NGC 1309. We update our previous results on the TRGB distances to five SN Ia host galaxies using the revised TRGB calibration. By combining the TRGB distance estimates to SN Ia host galaxies in this study with the SN Ia calibration provided by Riess et al. (2011), we obtain a value of the Hubble constant: H 0 = 71.66 ± 1.80(random) ± 1.88(systematic) km s‑1 Mpc‑1 (a 3.6% uncertainty including systematics) from all eight SNe, and H 0 = 73.72 ± 2.03 ± 1.94 km s‑1 Mpc‑1 (a 3.8% uncertainty) from six low-reddened SNe. We present our best estimate, H 0 = 71.17 ± 1.66 ± 1.87 km s‑1 Mpc‑1 (a 3.5% uncertainty) from six low-reddened SNe with the recent SN Ia calibration in Riess et al. (2016). This value is between those from the Cepheid calibrated SNe Ia and those from the Cosmic Microwave Background analysis, lowering the Hubble tension.

  16. Central Engine and Host Galaxy of RXJ 1301.9+2747: A Multiwavelength View of a Low-mass Black Hole Active Galactic Nuclei with Ultra-soft X-Ray Emission

    NASA Astrophysics Data System (ADS)

    Shu, X. W.; Wang, T. G.; Jiang, N.; Wang, J. X.; Sun, L. M.; Zhou, H. Y.

    2017-03-01

    RXJ 1301.9+2747 is an optically identified very-low-mass AGN candidate with {M}{BH}∼ 1× {10}6 {M}ȯ , which shows extremely soft X-ray emission and unusual X-ray variability in the form of short-lived flares. We present an analysis of multiwavelength observations of RXJ 1301.9+2747 in order to study the properties of the active nucleus and its host galaxy. The UV-to-X-ray spectrum in the quiescent state can be well and self-consistently described by a thermal and a Comptonized emission from the accretion disk, with the black body dominating ∼70% of the X-rays in the 0.2–2 keV. The same model can describe the X-ray spectrum in the flare state, but the Comptonized component becomes dominant (∼80%). The best fit implies an Eddington ratio of ∼0.14 and a black-hole mass of (1.7-2.8)× {10}6 M ⊙, in agreement with the estimation from the optical data within errors. However, the best-fitting model under predicts the optical flux for the HST point source by a factor of ∼2. The excess of nuclear optical emission could be attributed to a nuclear stellar cluster, which is frequently seen in low-mass AGNs. The X-ray to optical spectral slope ({α }{ox}) is lower than in most other active galaxies, which may be attributed to intrinsically X-ray weakness due to very little hot and optically thin coronal emission. We performed a pilot search for weak or hidden broad emission lines using optical spectropolarimetry observations, but no polarized broad lines are detected. The host galaxy appears to be a disk galaxy with a boxy pseudobulge or nuclear bar accounting for ∼15% of the total starlight, which is consistent with the general characteristics of the host of low-mass AGNs.

  17. The Cold Dust Content of Broad and Narrow-Line, Optically Luminous, nearby QSO

    NASA Astrophysics Data System (ADS)

    Petric, A.

    2015-09-01

    Observations of the dynamics of stars and gas in the nuclear regions of nearby galaxies suggest that the overwhelming majority of spheroidal galaxies in the local Universe contain massive BHs and that, with some important caveats, the masses of those central BH correlate with the velocity dispersions of the stars in the spheroid and the bulge luminosities. Much research has been dedicated to understanding the mechanisms responsible for such a fundamental perhaps causal relation. An accurate census of the basic properties of the cold interstellar medium (ISM) in AGN host is pertinent to those investigations because cold molecular gas is the basic fuel for star-formation and black hole growth. We present high sensitivity observations taken with the Herschel Space Observatory to measure the cold dust content in a sample of 85 nearby (z <= 0.5) QSOs chosen from the optically luminous broad-line PG QSOs sample and in a complementary sample of 85 narrow-line QSOs chosen to match the redshift and optical luminosity distribution of the broad-line targets. The FIR data are combined with near-infrared and mid-infrared measurements from the Two Micron All Sky Survey and the Wide-Field Infrared Survey Explorer to determine their IR spectral energy distributions which we use to assess aggregate dust properties. We investigate the relation between star-formation rates (SFRs) estimated from the IR luminosities and SFRs determined from measurements of the 11.3 micron PAH. The differences between the cold dust properties of narrow and broad line AGN will be discussed in the context of models that envision that quasar activity is triggered by gas-rich galaxy mergers.

  18. Galaxy pairs in deep HST images: Evidence for evolution in the galaxy merger rate

    NASA Technical Reports Server (NTRS)

    Burkey, Jordan M.; Keel, William C.; Windhorst, Rogier A.; Franklin, Barbara E.

    1994-01-01

    We use four deep serendipitous fields observed with the Hubble Space Telescope (HST) Wide-Field Camera to constrain the rate of galaxy merging between the current epoch and z approximately equals 0.7. Since most mergers occur between members of bound pairs, the merger rate is given to a good approximation by (half) the rate of disappearance of galaxies in pairs. An objective criterion for pair membership shows that 34% +/- 9% of our HST galaxies with I = 18-22 belong to pairs, compared to 7% locally. This means that about 13% of the galaxy population has disappeared due to merging in the cosmic epoch corresponding to this magnitude interval (or 0.1 approximately less than z approximately less than 0.7). Our pair fraction is a lower limit: correction for pair members falling below our detection threshold might raise the fraction to approximately 50%. Since we address only two-galaxy merging, these values do not include physical systems of higher multiplicity. Incorporating I-band field-galaxy redshift distributions, the pair fraction grows with redshift as alpha(1 + z)(exp 3.5 +/- 0.5) and the merger rate as (1 + z)(exp 2.5 +/- 0.5). This may have significant implications for the interpretation of galaxy counts (disappearance of faint blue galaxies), the cosmological evolution of faint radio sources and quasars (which evolve approximately as (1 + z)(exp 3), the similarity in the power law is necessary but not sufficient evidence for a causal relation), statistics of QSO companions, the galaxy content in distant clusters, and the merging history of a 'typical' galaxy.

  19. THE QSO HE 0450-2958: SCANTILY DRESSED OR HEAVILY ROBED? A NORMAL QUASAR AS PART OF AN UNUSUAL ULIRG

    SciTech Connect

    Jahnke, Knud; Elbaz, David; Pantin, Eric; Lagage, Pierre-Olivier; Letawe, Geraldine; Chantry, Virginie

    2009-08-01

    The luminous z = 0.286 quasar HE 0450-2958 is interacting with a companion galaxy at 6.5 kpc distance and the whole system radiates in the infrared (IR) at the level of an ultraluminous infrared galaxy (ULIRG). A so far undetected host galaxy triggered the hypothesis of a mostly 'naked' black hole (BH) ejected from the companion by three-body interaction. We present new Hubble Space Telescope (HST)/NICMOS 1.6 {mu}m imaging data at 0.''1 resolution and VLT/VISIR 11.3 {mu}m images at 0.''35 resolution that are for the first time resolving the system in the near- and mid-infrared. We combine these data with existing optical HST and CO maps. (1) At 1.6 {mu}m we find an extension NE of the quasar nucleus that is likely a part of the host galaxy, though not its main body. If true, a combination with upper limits on a main body co-centered with the quasar brackets the host-galaxy luminosity to within a factor of {approx}4 and places HE 0450-2958 directly onto the M{sub BH} - M{sub bulge} relation for nearby galaxies. (2) A dust-free line of sight to the quasar suggests a low dust obscuration of the host galaxy, but the formal upper limit for star formation (SF) lies at 60 M{sub sun} yr{sup -1}. HE 0450-2958 is consistent with lying at the high-luminosity end of Narrow-Line Seyfert 1 Galaxies, and more exotic explanations like a 'naked quasar' are unlikely. (3) All 11.3 {mu}m radiation in the system is emitted by the quasar nucleus. It has warm ULIRG-strength IR emission powered by BH accretion and is radiating at super-Eddington rate, L/L{sub Edd} = 6.2{sup +3.8}{sub -1.8}, or 12 M{sub sun} yr{sup -1}. (4) The companion galaxy is covered in optically thick dust and is not a collisional ring galaxy. It emits in the far-infrared at ULIRG strength, powered by Arp220-like SF (strong starburst-like). An M82-like SED is ruled out. (5) With its BH accretion rate, HE 0450-2958 produces not enough new stars to maintain its position on the M{sub BH} - M{sub bulge} relation, and SF

  20. IRAS observations of active galaxies

    NASA Technical Reports Server (NTRS)

    Neugebauer, G.; Soifer, B. T.; Rowan-Robinson, M.

    1985-01-01

    The IRAS survey gives an unbiased view of the infrared properties of the active galaxies. Seyfert galaxies occupy much the same area in color-color plots as to normal infrared bright galaxies, but extend the range towards flatter 60 to 25 mm slopes. Statistically the Seyfert 1 galaxies can be distinguished from the Seyfert 2 galaxies, lying predominantly closer to the area with constant slopes between 25 and 200 mm. The infrared measurements of the Seyfert galaxies cannot distinguish between the emission mechanisms in these objects although they agree with the currently popular ideas; they do provide a measure of the total luminosity of the Seyferts. The quasar's position in the color-color diagrams continue the trend of the Seyferts. The quasar 3C48 is shown to be exceptional among the radio loud quasars in that it has a high infrared luminosity which dominates the power output of the quasar and is most likely associated with the underlying host galaxy.

  1. PEARS Emission Line Galaxies

    NASA Technical Reports Server (NTRS)

    Pirzkal, Nor; Rothberg, Barry; Ly, Chun; Rhoads, James E.; Malhotra, Sangeeta; Grogin, Norman A.; Dahlen, Tomas; Meurer, Gerhardt R.; Walsh, Jeremy; Hathi, Nimish P.; Cohen, Seth; Belini, Andrea; Holwerda, Benne W.; Straughn, Amber; Mechtley, Matthew

    2012-01-01

    We present a full analysis of the Probing Evolution And Reionization Spectroscopically (PEARS) slitless grism spectroscopic data obtained vl'ith the Advanced Camera for Surveys on HST. PEARS covers fields within both the Great Observatories Origins Deep Survey (GOODS) North and South fields, making it ideal as a random surveY of galaxies, as well as the availability of a wide variety of ancillary observations to support the spectroscopic results. Using the PEARS data we are able to identify star forming galaxies within the redshift volume 0 < z < 1.5. Star forming regions in the PEARS survey are pinpointed independently of the host galaxy. This method allOW8 us to detect the presence of multiple emission line regions (ELRs) within a single galaxy. 1162 [OII], [OIII] and/or H-alpha emission lines have been identified in the PEARS sample of approx 906 galaxies down to a limiting flux of approx 10 - 18 erg/s/sq cm . The ELRs have also been compared to the properties of the host galaxy, including morphology, luminosity, and mass. From this analysis we find three key results: 1) The computed line luminosities show evidence of a flattening in the luminosity function with increasing redshift; 2) The star forming systems show evidence of disturbed morphologies, with star formation occurring predominantly within one effective (half-light) radius. However, the morphologies show no correlation with host stellar mass; and 3) The number density of star forming galaxies with M(*) >= 10(exp 9) Solar M decreases by an order of magnitude at z<=0.5 relative to the number at 0.5 < z < 0.9 in support of the argument for galaxy downsizing.

  2. Disrupted Stars in Unusual Galaxies

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-03-01

    Tidal disruption events (TDEs) occur when a star passes a little too close to a supermassive black hole at the center of a galaxy. Tidal forces from the black hole cause the passing star to be torn apart, resulting in a brief flare of radiation as the stars material accretes onto the black hole. A recent study asks the following question: do TDEs occur most frequently in an unusual type of galaxy?A Trend in DisruptionsSo far, we have data from eight candidate TDEs that peaked in optical and ultraviolet wavelengths. The spectra from these observations have shown an intriguing trend: many of these TDEs host galaxies exhibit weak line emission (indicating little or no current star-formation activity), and yet they show strong Balmer absorption lines (indicating star formation activity occurred within the last Gyr). These quiescent, Balmer-strong galaxies likely underwent a period of intense star formation that recently ended.To determine if TDEs are overrepresented in such galaxies, a team of scientists led by Decker French (Steward Observatory, University of Arizona) has quantified the fraction of galaxies in the Sloan Digital Sky Survey (SDSS) that exhibit similar properties to those of TDE hosts.Quantifying OverrepresentationSpectral characteristics of SDSS galaxies (gray) and TDE candidate host galaxies (colored points): line emission vs. Balmer absorption. The lower right-hand box identifies thequiescent, Balmer-strong galaxies which contain most TDE events, yet are uncommon among the galaxy sample as a whole. Click for a better look! [French et al. 2016]French and collaborators compare the optical spectra of the TDE host galaxies to those of nearly 600,000 SDSS galaxies, using two different cutoffs for the Balmer absorption the indicator of past star formation. Their strictest cut, filtering for very high Balmer absorption, selected only 0.2% of the SDSS galaxies, yet 38% of the TDEs are hosted in such galaxies. Using a more relaxed cutoff selects 2.3% of

  3. Central black hole masses of galaxies

    NASA Astrophysics Data System (ADS)

    Fan, Jun-Hui

    2003-11-01

    In this paper, the stellar velocity dispersions in the host galaxies are used to estimate the central black hole masses for a sample of elliptical galaxies. We find that the central black hole masses are in the range of 10(5.5-9.5)Modot. Based on the estimated masses in this paper and those by Woo & Urry (2002) and the measured host galaxy absolute magnitude, a relation, log (MBH/Modot) = -(0.25±4.3×10-3)MR + (2.98±0.208) is found for central black hole mass and the host galaxy magnitude. Some discussions are presented.

  4. BREAKING THE OBSCURING SCREEN: A RESOLVED MOLECULAR OUTFLOW IN A BURIED QSO

    SciTech Connect

    Rupke, David S. N.; Veilleux, Sylvain

    2013-09-20

    We present Keck laser guide star adaptive optics observations of the nearby buried quasi-stellar object (QSO) F08572+3915:NW. We use near-infrared integral field data taken with the OH-Suppressing Infra-Red Imaging Spectrograph to reveal a compact disk and molecular outflow using Paα and H{sub 2} rotational-vibrational transitions at a spatial resolution of 100 pc. The outflow emerges perpendicular to the disk into a bicone of one-sided opening angle 100° up to distances of 400 pc from the nucleus. The integrated outflow velocities, which reach at least –1300 km s{sup –1}, correspond exactly to those observed in (unresolved) OH absorption, but are smaller (larger) than those observed on larger scales in the ionized (neutral atomic) outflow. These data represent a factor of >10 improvement in the spatial resolution of molecular outflows from mergers/QSOs, and plausibly represent the early stages of the excavation of the dust screen from a buried QSO.

  5. Dwarf galaxy evolution within the environments of massive galaxies

    NASA Astrophysics Data System (ADS)

    Arraki, Kenza S.; Klypin, Anatoly A.; Ceverino, Daniel; Trujillo-Gomez, Sebastian; Primack, Joel R.

    2016-01-01

    Understanding galaxy evolution depends on connecting large-scale structure determined by the ΛCDM model with, at minimum, the small-scale physics of gas, star formation, and stellar feedback. Formation of galaxies within dark matter halos is sensitive to the physical phenomena occurring within and around the halo. This is especially true for dwarf galaxies, which have the smallest potential wells and are more susceptible to the effects of gas ionization and removal than larger galaxies. At dwarf galaxies scales comparisons of dark matter-only simulations with observations has unveiled various differences including the core-cusp, the missing satellites, and the too-big-to-fail problems. We have run a new suite of hydrodynamical simulations using the ART code to examine the evolution of dwarf galaxies in massive host environments. These are cosmological zoom-in simulations including deterministic star formation and stellar feedback in the form of supernovae feedback, stellar winds, radiation pressure, and photoionization pressure. We simulates galaxies with final halo masses on the order of 1012 M⊙ with high resolution, allowing us to examine the satellite dwarf galaxies and local isolated dwarf galaxies around each primary galaxy. We analyzed the abundance and structure of these dwarfs specifically the velocity function, their star formation rates, core creation and the circumgalactic medium. By reproducing observations of dwarf galaxies in simulations we show how including baryons in simulations relieves tensions seen in comparing dark matter only simulations with observations.

  6. High redshift radio galaxies

    NASA Technical Reports Server (NTRS)

    Mccarthy, Patrick J.

    1993-01-01

    High redshift galaxies that host powerful radio sources are examined. An overview is presented of the content of radio surveys: 3CR and 3CRR, 4C and 4C/USS, B2/1 Jy, MG, MRC/1Jy, Parkes/PSR, B3, and ESO Key-Project. Narrow-line radio galaxies in the visible and UV, the source of ionization and excitation of the emission lines, emission-line luminosities, morphology of the line-emitting gas, physical properties and energetics, kinematics of the line-emitting gas, and implications from the emission lines are discussed. The morphologies and environments of the host galaxies, the alignment effect, and spectral energy distributions and ages are also examined.

  7. Closing in on a Short-Hard Burst Progenitor: Constraints From Early-Time Optical Imaging and Spectroscopy of a Possible Host Galaxy of GRB 050509b

    SciTech Connect

    Bloom, Joshua S.; Prochaska, J.X.; Pooley, D.; Blake, C.W.; Foley, R.J.; Jha, S.; Ramirez-Ruiz, E.; Granot, J.; Filippenko, A.V.; Sigurdsson, S.; Barth, A.J.; Chen, H.-W.; Cooper, M.C.; Falco, E.E.; Gal, R.R.; Gerke, B.F.; Gladders, M.D.; Greene, J.E.; Hennanwi, J.; Ho, L.C.; Hurley, K.; /UC, Berkeley, Astron. Dept. /Lick Observ. /Harvard-Smithsonian Ctr. Astrophys. /Princeton, Inst. Advanced Study /KIPAC, Menlo Park /Penn State U., Astron. Astrophys. /UC, Irvine /MIT, MKI /UC, Davis /UC, Berkeley /Carnegie Inst. Observ. /UC, Berkeley, Space Sci. Dept. /Michigan U. /LBL, Berkeley /Spitzer Space Telescope

    2005-06-07

    The localization of the short-duration, hard-spectrum gamma-ray burst GRB050509b by the Swift satellite was a watershed event. Never before had a member of this mysterious subclass of classic GRBs been rapidly and precisely positioned in a sky accessible to the bevy of ground-based follow-up facilities. Thanks to the nearly immediate relay of the GRB position by Swift, we began imaging the GRB field 8 minutes after the burst and have continued during the 8 days since. Though the Swift X-ray Telescope (XRT) discovered an X-ray afterglow of GRB050509b, the first ever of a short-hard burst, thus far no convincing optical/infrared candidate afterglow or supernova has been found for the object. We present a re-analysis of the XRT afterglow and find an absolute position of R.A. = 12h36m13.59s, Decl. = +28{sup o}59'04.9'' (J2000), with a 1{sigma} uncertainty of 3.68'' in R.A., 3.52'' in Decl.; this is about 4'' to the west of the XRT position reported previously. Close to this position is a bright elliptical galaxy with redshift z = 0.2248 {+-} 0.0002, about 1' from the center of a rich cluster of galaxies. This cluster has detectable diffuse emission, with a temperature of kT = 5.25{sub -1.68}{sup +3.36} keV. We also find several ({approx}11) much fainter galaxies consistent with the XRT position from deep Keck imaging and have obtained Gemini spectra of several of these sources. Nevertheless we argue, based on positional coincidences, that the GRB and the bright elliptical are likely to be physically related. We thus have discovered reasonable evidence that at least some short-duration, hard-spectra GRBs are at cosmological distances. We also explore the connection of the properties of the burst and the afterglow, finding that GRB050509b was underluminous in both of these relative to long-duration GRBs. However, we also demonstrate that the ratio of the blast-wave energy to the {gamma}-ray energy is consistent with that of long-duration GRBs. We thus find plausible

  8. Observations of QSO J2233-606 in the Southern Hubble Deep Field

    NASA Astrophysics Data System (ADS)

    Sealey, K. M.; Drinkwater, M. J.; Webb, J. K.

    1998-06-01

    The Hubble Deep Field South (HDF-S) Hubble Space Telescope (HST) observations are expected to begin in 1998 October. We present a composite spectrum of the QSO in the HDF-S field covering UV/optical/near-IR wavelengths, obtained by combining data from the Australian National University 2.3 m telescope with STIS on the HST.1 This intermediate-resolution spectrum covers the range 1600-10000 Å and allows us to derive some basic information on the intervening absorption systems which will be important in planning future higher resolution studies of this QSO. The QSO J2233-606 coordinates are α = 22h33m37.6s, δ = -60°33'29" (J2000), the magnitude is B = 17.5, and its redshift is zem = 2.238, derived by simultaneously fitting several emission lines. The spectral index is α = -0.7 +/- 0.1, measured between the Lyα and Mg II emission lines. Many absorption systems are present, including systems with metal lines redward of the Lyα emission line at zabs = 2.204, 1.942, 1.870, 1.787 and a few very strong Lyα features at zabs = 2.077, 1.928, without similarly strong metal lines. There is a conspicuous Lyman limit (LL) absorption system that is most likely associated with the zabs = 1.942 system with a neutral hydrogen column density of NH I = (3.1 +/- 1.0) × 1017 cm-2. There is some evidence for the presence of a second LL absorber just to the blue of the conspicuous system at z = 1.870. We have employed a new technique, based on an analysis of the shape of the observed spectrum in the region of the LL absorption, to explore the properties of the gas. We tentatively conclude that this system might have suitable characteristics for measuring the deuterium-to-hydrogen (D/H) ratio.

  9. The Circumgalactic Medium surrounding =2.3 Star-Forming Galaxies in the Keck Baryonic Structure Survey

    NASA Astrophysics Data System (ADS)

    Rudie, Gwen C.

    2013-01-01

    The gaseous environments of galaxies are a crucial but poorly-constrained component of galaxy formation and evolution and contain vital information about the movement of baryons into and out of galaxies. I will present results from the Keck Baryonic Structure Survey (KBSS), a unique spectroscopic survey designed to explore the connection between galaxies and intergalactic baryons during the cosmic peak of star formation ( 2-3). The KBSS combines Keck/HIRES spectra of 15 hyperluminous QSOs with densely-sampled galaxy redshift surveys surrounding each QSO sightline. Through Voigt profile decomposition of ~6000 HI absorbers within the Lya forest in the QSO spectra, my thesis provides the first measurements of the physical properties of the circumgalactic medium (CGM) of high-redshift galaxies characterizing the distribution, HI column densities (NHI), kinematics, and line widths of the gas within 50 kpc to 3 Mpc of 886 foreground galaxies. We find that the strongest absorbers within 100 kpc of galaxies have 1000 times higher NHI than typical IGM values and that the strongest absorption is found within 300 kpc and 300 km/s of galaxies. The spatial covering fraction, multiplicity, and characteristic NHI remain elevated to transverse distances of 2 Mpc while redshift anisotropies on these scales indicate coherent infall. The Doppler widths of CGM absorbers are ~50% larger than average, suggesting higher temperatures and/or increased turbulence likely caused by accretion shocks and/or galactic winds. Comparison with recent theoretical predictions reveals significant discrepancies suggesting that the current understanding of gas flows remains incomplete. Ongoing analysis of metallic CGM absorption features will provide unique insight into the metallicity and physical state of the CGM. Collectively, these measurements yield the first constraints of the co-evolution of galaxies and the IGM, the nature of baryonic flows, and the effect of star formation on both the IGM and on

  10. ORBITAL DEPENDENCE OF GALAXY PROPERTIES IN SATELLITE SYSTEMS OF GALAXIES