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Sample records for 12micron seyfert sample

  1. The Far-Infrared Energy Distributions of Seyfert and Starburst Galaxies in the Local Universe: Infrared Space Observatory Photometry of the 12 Micron Active Galaxy Sample

    NASA Astrophysics Data System (ADS)

    Spinoglio, Luigi; Andreani, Paola; Malkan, Matthew A.

    2002-06-01

    New far-infrared photometry with ISOPHOT aboard the Infrared Space Observatory (ISO) is presented for 58 galaxies with homogeneous published data for another 32 galaxies, all belonging to the 12 μm galaxy sample-in total, 29 Seyfert 1 galaxies, 35 Seyfert 2 galaxies, and 12 starburst galaxies, or about half of the 12 μm active galaxy sample, plus 14 normal galaxies for comparison. ISO and Infrared Astronomical Satellite (IRAS) data are used to define color-color diagrams and spectral energy distributions (SEDs). Thermal dust emission at two temperatures (one cold at 15-30 K and one warm at 50-70 K) can fit the 60-200 μm SED, with a dust emissivity law proportional to the inverse square of the wavelength. Seyfert 1 galaxies and Seyfert 2 galaxies are indistinguishable longward of 100 μm, while, as already seen by IRAS, the former have flatter SEDs shortward of 60 μm. A mild anticorrelation is found between the [200-100] color and the ``60 μm excess.'' We infer that this is due to the fact that galaxies with a strong starburst component and thus a strong 60 μm flux have a steeper far-infrared turnover. In non-Seyfert galaxies, increasing the luminosity corresponds to increasing the star formation rate, which enhances the 25 and 60 μm emission. This shifts the peak emission from around 150 μm in the most quiescent spirals to shorter than 60 μm in the strongest starburst galaxies. To quantify these trends further, we identified with the IRAS colors three idealized infrared SEDs: pure quiescent disk emission, pure starburst emission, and pure Seyfert nucleus emission. Even between 100 and 200 μm, the quiescent disk emission remains much cooler than the starburst component. Seyfert galaxies have 100-200 μm SEDs ranging from pure disks to pure starbursts, with no apparent contribution from their active nuclei at those wavelengths. Based on observations with ISO, an ESA project with instruments funded by ESA Member States (especially the PI countries: France

  2. Testing different AGN tracers on a local sample of Seyfert galaxies

    NASA Astrophysics Data System (ADS)

    Pozzi, F.

    2016-08-01

    I will present our new study on a local sample of Seyfert galaxies selected at 12 micron. This sample, given its plenty of information, both photometric and spectroscopic, is a perfect sample to compare, from a statistical point of view, different AGN selection criteria, and AGN derived intrinsic properties. In detail, I will compare AGN activity derived from SED-fitting technique, X-ray luminosity and AGN activity traced by high excitation IR lines, like [NeV] and [OIV]. Moreover, for one particular obscured X-ray Compton-thick source, thanks also to the availability of ALMA data, I will derive a self-consistent overview of the physics behind the emission in different bands,by taking advantage of the photoionization code CLOUDY.

  3. Soft X-ray properties of a spectroscopically selected sample of interacting and isolated Seyfert galaxies

    NASA Astrophysics Data System (ADS)

    Pfefferkorn, F.; Boller, Th.; Rafanelli, P.

    2001-03-01

    We present a catalogue of ROSAT detected sources in the sample of spectroscopically selected Seyfert 1 and Seyfert 2 galaxies of Rafanelli et al. (\\cite{Rafanelli95}). The catalogue contains 102 Seyfert 1 and 36 Seyfert 2 galaxies. The identification is based on X-ray contour maps overlaid on optical images taken from the Digitized Sky Survey. We have derived the basic spectral and timing properties of the X-ray detected Seyfert galaxies. For Seyfert 1 galaxies a strong correlation between photon index and X-ray luminosity is detected. We confirm the presence of generally steeper X-ray continua in narrow-line Seyfert 1 galaxies (NLS1s) compared to broad-line Seyfert 1 galaxies. Seyfert 2 galaxies show photon indices similar to those of NLS1s. Whereas a tendency for an increasing X-ray luminosity with increasing interaction strength is found for Seyfert 1 galaxies, such a correlation is not found for Seyfert 2 galaxies. For Seyfert 1 galaxies we found also a strong correlation for increasing far-infrared luminosity with increasing interaction strength. Both NLS1s and Seyfert 2 galaxies show the highest values of far-infrared luminosity compared to Seyfert 1 galaxies, suggesting that NLS1s and Seyfert 2 galaxies host strong (circumnuclear) star formation. For variable Seyfert galaxies we present the X-ray light curves obtained from the ROSAT All-Sky Survey and from ROSAT PSPC and HRI pointed observations. Besides the expected strong short- and long-term X-ray variability in Seyfert 1 galaxies, we find indications for X-ray flux variations in Seyfert 2 galaxies. All overlays can be retrieved via CDS anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5)} or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/368/797

  4. The 1.2 micron CMOS technology

    NASA Technical Reports Server (NTRS)

    Pina, C. A.

    1985-01-01

    A set of test structures was designed using the Jet Propulsion Laboratory (JPL) test chip assembler and was used to evaluate the first CMOS-bulk foundry runs with feature sizes of 1.2 microns. In addition to the problems associated with the physical scaling of the structures, this geometry provided an additional set of problems, since the design files had to be generated in such a way as to be capable of being processed through p-well, n-well, and twin-well processing lines. This requirement meant that the files containing the geometric design rules as well as the structure design files had to produce process-insensitive designs, a requirement that does not apply to the more mature 3.0-micron CMOS feature size technology. Because of the photolithographic steps required with this feature size, the maximum allowable chip size was 10 x 10 mm, and this chip was divided into 24 project areas, with each area being 1.6 x 1.6 mm in size. The JPL-designed structures occupied 13 out of the 21 allowable project sizes and provided the only test information obtained from these three preliminary runs. The structures were used to successfully evaluate three different manufacturing runs through two separate foundries.

  5. Relativistic Reflection in a sample of Seyfert 1 galaxies observed with Suzaku

    NASA Astrophysics Data System (ADS)

    Mantovani, G.; Nandra, K.; Ponti, G.

    2016-08-01

    Broad iron lines are expected, and observed, to be a widespread feature in bright AGN. However, a significant fraction of object misses a disk line component. We extracted from the sample of all Seyfert 1 galaxies the ones with no detection of a broad Fe Kα line, to investigate the physical cause of this absence. We analysed all archival Suzaku observations that, thanks to the broad energy band, allows us to investigate the connection between broad Fe Kα line and reflection continuum. Our analysis shows that relativistic FeKα line are ubiquitous features in the spectra of Seyfert galaxies, but are often difficult to detect without very high quality data. We also investigate the relation between the Fe Kα line and the reflection continuum. For most of the sample, the strength of the reflection component is consistent with that of the line.

  6. Mid-IR Spectra of HED Meteorites and Synthetic Pyroxenes: Reststrahlen Features (9-12 micron)

    NASA Technical Reports Server (NTRS)

    Lim, Lucy F.; Emery, Joshua P.; Moskovitz, Nicholas A.

    2010-01-01

    In an earlier study. Hamilton (2000) mapped the behavior of the 9-12 micron reststrahlen structures with composition in a suite of primarily natural terrestrial pyroxenes. Here we examine the same set of reststrahlen features in the spectra of diogenites and eucrites and place them in the context of the terrestrial samples and of a suite of well-characterized synthetic pyroxenes. The results will be useful to the interpretation of mid-IR spectra of 4 Vesta and other basaltic asteroids.

  7. Cloud properties inferred from 8-12 micron data

    NASA Technical Reports Server (NTRS)

    Strabala, Kathleen I.; Ackerman, Steven A.; Menzel, W. Paul

    1994-01-01

    A trispectral combination of observations at 8-, 11-, and 12-micron bands is suggested for detecting cloud and cloud properties in the infrared. Atmospheric ice and water vapor absorption peak in opposite halves of the window region so that positive 8-minus-11-micron brightness temperature differences indicate cloud, while near-zero or negative differences indicate clear regions. The absorption coefficient for water increases more between 11 and 12 microns than between 8 and 11 microns, while for ice, the reverse is true. Cloud phases is determined by a scatter diagram of 8-minus-11-micron versus 11-minus-12-micron brightness temperature differences; ice cloud shows a slope greater than 1 and water cloud less than 1. The trispectral brightness temperature method was tested upon high-resolution interferometer data resulting in clear-cloud and cloud-phase delineation. Simulations using differing 8-micron bandwidths revealed no significant degradation of cloud property detection. Thus, the 8-micron bandwidth for future satellites can be selected based on the requirements of other applications, such as surface characterization studies. Application of the technique to current polar-orbiting High-Resolution Infrared Sounder (HIRS)-Advanced Very High Resolution Radiometer (AVHRR) datasets is constrained by the nonuniformity of the cloud scenes sensed within the large HIRS field of view. Analysis of MAS (MODIS Airborne Simulator) high-spatial resolution (500 m) data with all three 8-, 11-, and 12-micron bands revealed sharp delineation of differing cloud and background scenes, from which a simple automated threshold technique was developed. Cloud phase, clear-sky, and qualitative differences in cloud emissivity and cloud height were identified on a case study segment from 24 November 1991, consistent with the scene. More rigorous techniques would allow further cloud parameter clarification. The opportunities for global cloud delineation with the Moderate-Resolution Imaging

  8. The brightest high-latitude 12-micron IRAS sources

    NASA Technical Reports Server (NTRS)

    Hacking, P.; Beichman, C.; Chester, T.; Neugebauer, G.; Emerson, J.

    1985-01-01

    The Infrared Astronomical Satellite (IRAS) Point Source catalog was searched for sources brighter than 28 Jy (0 mag) at 12 microns with absolute galactic latitude greater than 30 deg excluding the Large Magellanic Cloud. The search resulted in 269 sources, two of which are the galaxies NGC 1068 and M82. The remaining 267 sources are identified with, or have infrared color indices consistent with late-type stars some of which show evidence of circumstellar dust shells. Seven sources are previously uncataloged stars. K and M stars without circumstellar dust shells, M stars with circumstellar dust shells, and carbon stars occupy well-defined regions of infrared color-color diagrams.

  9. A spectroscopic analysis of a sample of narrow-line Seyfert 1 galaxies selected from the Sloan Digital Sky Survey

    NASA Astrophysics Data System (ADS)

    Cracco, V.; Ciroi, S.; Berton, M.; Di Mille, F.; Foschini, L.; La Mura, G.; Rafanelli, P.

    2016-10-01

    We revisited the spectroscopic characteristics of narrow-line Seyfert 1 galaxies (NLS1s) by analysing a homogeneous sample of 296 NLS1s at redshift between 0.028 and 0.345, extracted from the Sloan Digital Sky Survey (SDSS-DR7) public archive. We confirm that NLS1s are mostly characterized by Balmer lines with Lorentzian profiles, lower black hole masses and higher Eddington ratios than classic broad-line Seyfert 1 (BLS1s), but they also appear to be active galactic nuclei (AGNs) contiguous with BLS1s and sharing with them common properties. Strong Fe II emission does not seem to be a distinctive property of NLS1s, as low values of Fe II/Hβ are equally observed in these AGNs. Our data indicate that Fe II and Ca II kinematics are consistent with the one of Hβ. On the contrary, O I λ8446 seems to be systematically narrower and it is likely emitted by gas of the broad-line region more distant from the ionizing source and showing different physical properties. Finally, almost all NLS1s of our sample show radial motions of the narrow-line region highly ionized gas. The mechanism responsible for this effect is not yet clear, but there are hints that very fast outflows require high continuum luminosities (>1044 erg s-1) or high Eddington ratios (log (Lbol/LEdd) > -0.1).

  10. A Sample of IRAS Infrared-selected Seyfert 1.5 Galaxies: Infrared Color α(60, 25)-dominated Eigenvector 1

    NASA Astrophysics Data System (ADS)

    Wang, J.; Wei, J. Y.; He, X. T.

    2006-02-01

    The well-documented E1 relationships are first extended to infrared color α(60, 25) and flux ratio [O III]/Hβn by comparing emission-line properties to continuum properties in infrared wavelengths. Both direct correlations and a principal component analysis are used in a sample of 50 IRAS IR-selected Seyfert 1.5 galaxies. In addition, to confirm the correlations of E1 in Boroson & Green, our eigenvector 1 turns out to be dominated by the mid-infrared color α(60, 25) and most strongly affected by RFe, [O III]/Hβn, and EW(Hβb). Our analysis indicates that the objects with large E1 tend to coexist with relatively young nuclear stellar populations, which implies that E1 is related to the nuclear star formation history. The IR-dominated eigenvector 1 can therefore be inferred to be interpreted as the ``age'' of an AGN. In confirmation of the work of Xu and coworkers, it is clear that the extreme Seyfert galaxies with both large RFe and large [O III]/Hβn are rare in our universe.

  11. Black hole mass estimate for a sample of radio-loud narrow-line Seyfert 1 galaxies

    NASA Astrophysics Data System (ADS)

    Calderone, G.; Ghisellini, G.; Colpi, M.; Dotti, M.

    2013-05-01

    We discuss the relationship between a standard Shakura & Sunyaev accretion disc model and the big blue bump (BBB) observed in Type 1 active galactic nuclei. Given the similarity between the BBB and the predicted disc spectrum, we propose a new method to estimate black hole masses which relies on the modelling of both optical and UV data with a Shakura & Sunyaev disc spectrum. We apply this method to a sample of 23 radio-loud narrow-line Seyfert 1 (RL-NLS1) galaxies, using data from Wide-field Infrared Survey Explorer, SDSS and GALEX. Our black hole mass estimates are at least a factor of ˜6 above previous results based on single epoch virial methods, while the Eddington ratios are correspondingly lower. Hence, the black hole masses of RL-NLS1 galaxies are typically above 108 M⊙, in agreement with the typical black hole mass of blazars.

  12. Microvariability in Seyfert galaxies

    USGS Publications Warehouse

    Carini, M.T.; Noble, J.C.; Miller, H.R.

    2003-01-01

    We present the results of a search for microvariability in a sample of eight Seyfert galaxies. Microvariability (i.e., variations occurring on timescales of tens of minutes to hours) has been conclusively demonstrated to exist in the class of active galactic nuclei (AGNs) known as blazars. Its existence in other classes of AGNs is far less certain. We present the results of a study of eight Seyfert 1 galaxies, which were intensively monitored in order to determine whether such variations exist in these objects. Only one object, Ark 120, displayed any evidence of microvariations. The implications of these results with respect to current models of the mechanisms responsible for the observed emission in Seyfert galaxies are discussed. We compare our results with those obtained from other studies of microvariability in different classes of AGNs.

  13. Search for Vega-like nearby stars with 12 micron excess

    NASA Technical Reports Server (NTRS)

    Aumann, Hartmut H.; Probst, Ronald G.

    1991-01-01

    The identification of Vega-like main-sequence stars with 10-micron excess would permit important measurements of the spatial extent of the radiating material with ground-based telescopes. In fact, 55 of the 548 nearby A, F, G, and K dwarfs with IRAS catalog magnitudes at 12 microns appear to have excess 12-micron flux. However, for only two of these stars, Beta Pic and Zeta Lep, was it possible, using small-aperture photometry at 2.2 and 10 microns, to verify that the 12-micron excess is with high likelihood associated with the star. For the remaining stars the apparent 12-micron color of the 106 A, F, G, and K stars in the observing program is only 0.02 mag. Excess flux due to a Vega-like cloud which may surround some of the sources in the observing program, like Alpha Lyrae, is thus typically not detectable at 10 microns.

  14. Warm Absorbers in X-rays (WAX), a comprehensive high resolution grating spectral study of a sample of Seyfert galaxies

    NASA Astrophysics Data System (ADS)

    Laha, S.; Guainazzi, M.; Dewangan, G.; Chakravorty, S.; Kembhavi, A.

    2014-07-01

    We present results from a homogeneous analysis of the broadband 0.3-10 keV CCD resolution as well as of soft X-ray high-resolution grating spectra of a hard X-ray flux-limited sample of 26 Seyfert galaxies observed with XMM-Newton. We could put a strict lower limit on the detection fraction of 50%. We find a gap in the distribution of the ionisation parameter in the range 0.5

  15. New Constraints on the Unified Model of Seyfert Galaxies

    NASA Astrophysics Data System (ADS)

    Maiolino, R.; Ruiz, M.; Rieke, G. H.; Keller, L. D.

    1995-06-01

    We present new 10 microns (N-band) photometry for 70 Seyfert galaxies, 43 of them previously unobserved. These observations, together with those collected from the literature, complete the 10 microns photometry for the CfA Sy galaxies and cover 80% of the Sy found in the RSA and 70% of the Sy in the IRAS 12 microns sample. From this data set, we find that Sy not showing any evidence for broad lines are systematically weaker in 10 microns nuclear emission than Sy nuclei having broad lines. This result may indicate the existence of a group of very low-luminosity Sy2 galaxies that do not have Sy1 counterparts in equal numbers, contrary to the strict unified theory. Alternately, the result can be reconciled with unified theories if a specific type of geometry is assumed for the circumnuclear obscuring material. By comparing the 10 microns ground-based observations with the IRAS 12 microns fluxes, we also study the properties of the extended mid-IR emission, i.e., the star forming activity of the host galaxy of the Sy nucleus. We find Sy2 to lie preferentially in galaxies experiencing enhanced star-forming activity, while Sy1 lie in normal or quiescent galaxies. This result appears to be inconsistent with the strict unified model, since the host galaxy properties should be independent of the orientation of a circumnuclear torus and therefore should be independent of nuclear type. Our finding could be explained by adding to the unified model a link between star-forming activity and the amount of obscuring material collected in the circumnuclear region.

  16. A Comprehensive Study of 2000 Narrow Line Seyfert 1 Galaxies from the Sloan Digital Sky Survey. I. The Sample

    NASA Astrophysics Data System (ADS)

    Zhou, Hongyan; Wang, Tinggui; Yuan, Weimin; Lu, Honglin; Dong, Xiaobo; Wang, Junxian; Lu, Youjun

    2006-09-01

    This is the first paper in a series dedicated to the study of the emission-line and continuum properties of narrow line Seyfert 1 galaxies (NLS1s). We carried out a systematic search for NLS1s from objects assigned as ``QSOs'' or ``galaxies'' in the spectroscopic sample of the Sloan Digital Sky Survey Data Release 3 (SDSS DR3) by a careful modeling of their emission lines and continua. The result is a uniform sample comprising ~2000 NLS1s. This sample dramatically increases the number of known NLS1s by a factor of ~10 over previous compilations. This paper presents the parameters of the prominent emission lines and continua, which were measured accurately with typical uncertainties <10%. Taking advantage of such an unprecedented large and uniform sample with accurately measured spectral parameters, we carried out various statistical analyses, some of which were only possible for the first time. The main results found are as follows. (1) Within the overall Seyfert 1 population, the incidence of NLS1s is strongly dependent on the optical, X-ray, and radio luminosities as well as the radio loudness. The fraction of NLS1s peaks around SDSS g-band absolute magnitude Mg~-22 mag in the optical and ~1043.2 ergs s-1 in the soft X-ray band, and decreases quickly as the radio loudness increases. (2) On average the relative Fe II emission, R4570=Fe II λλ4434-4684/Hβ, in NLS1s is about twice that in normal active galactic nuclei (AGNs) and is anticorrelated with the broad component width of the Balmer emission lines. (3) The well-known anticorrelation between the width of broad low-ionization lines and the soft X-ray spectral slope for broad line AGNs extends down to FWHM~1000 km s-1 in NLS1s, but the trend appears to reverse at still smaller line widths. (4) The equivalent width of Hβ and Fe II emission lines are strongly correlated with the Hβ and continuum luminosities. (5) We do not find any difference between NLS1s and normal AGNs in regard to the narrow line region

  17. A new sample of X-ray selected narrow emission-line galaxies. II. Looking for True Seyfert 2

    NASA Astrophysics Data System (ADS)

    Pons, E.; Watson, M. G.

    2016-10-01

    A sample of X-ray and optically selected narrow emission-line galaxies (769 sources) from the 3XMM catalogue cross-correlated with SDSS (DR9) catalogue has been studied. Narrow-emission line active galactic nuclei (AGN; type-2) have been selected on the basis of their emission line ratios and/or X-ray luminosity. We have looked for X-ray unobscured type-2 AGN. As X-ray spectra were not available for our whole sample, we have checked the reliability of using the X-ray hardness ratio (HR) as a probe of the level of obscuration and we found a very good agreement with full spectral fitting results, with only 2% of the sources with apparently unobscured HR turning out to have an obscured spectrum. Despite the fact that type-2 AGN are supposed to be absorbed based on the Unified Model, about 60% of them show no sign or very low level of X-ray obscuration. After subtraction of contaminants to the sample, that is Narrow-Line Seyfert 1 and Compton-thick AGN, the fraction of unobscured Sy2 drops to 47%. For these sources, we were able to rule out dust reddening and variability for most of them as an explanation of the absence of optical broad emission-lines. The main explanations remaining are the dilution of weak/very broad emission-lines by the host galaxy and the intrinsic absence of the broad-line region (BLR) due to low accretion rates (i.e. True Sy2). However, the number of True Sy2 strongly depends on the method used to verify the intrinsic lack of broad lines. Indeed using the optical continuum luminosity to predict the BLR properties gives a much larger fraction of True Sy2 (about 90% of the unobscured Sy2 sample) than the use of the X-ray 2 keV luminosity (about 20%). Nevertheless the number of AGN we securely detected as True Sy2 is at least three times larger that the previously confirmed number of True Sy2.

  18. Temperature dependence of intensities of the 8-12 micron bands of CFCl3

    NASA Technical Reports Server (NTRS)

    Nanes, R.; Silvaggio, P. M.; Boese, R. W.

    1980-01-01

    The absolute intensities of the 8-12 micron bands from Freon 11 (CFCl3) were measured at temperatures of 294 and 216 K. Intensities of the bands centered at 798, 847, 934, and 1082 per cm are all observed to depend on temperature. The temperature dependence for the 847 and 1082 per cm fundamental regions is attributed to underlying hot bands; for the nu2 + nu5 combination band (934 per cm), the observed temperature dependence is in close agreement with theoretical prediction. The implication of these results on atmospheric IR remote-sensing is briefly discussed.

  19. A SAMPLE OF SEYFERT-2 GALAXIES WITH ULTRALUMINOUS GALAXY-WIDE NARROW-LINE REGIONS: QUASAR LIGHT ECHOES?

    SciTech Connect

    Schirmer, M.; Diaz, R.; Levenson, N. A.; Winge, C.; Holhjem, K.

    2013-01-20

    We report the discovery of Seyfert-2 galaxies in SDSS-DR8 with galaxy-wide, ultraluminous narrow-line regions (NLRs) at redshifts z = 0.2-0.6. With a space density of 4.4 Gpc{sup -3} at z {approx} 0.3, these 'green beans' (GBs) are amongst the rarest objects in the universe. We are witnessing an exceptional and/or short-lived phenomenon in the life cycle of active galactic nuclei (AGNs). The main focus of this paper is on a detailed analysis of the GB prototype galaxy J2240-0927 (z = 0.326). Its NLR extends over 26 Multiplication-Sign 44 kpc and is surrounded by an extended NLR. With a total [O III] {lambda}5008 luminosity of (5.7 {+-} 0.9) Multiplication-Sign 10{sup 43} erg s{sup -1}, this is one of the most luminous NLRs known around any type-2 galaxy. Using VLT/XSHOOTER, we show that the NLR is powered by an AGN, and we derive resolved extinction, density, and ionization maps. Gas kinematics is disturbed on a global scale, and high-velocity outflows are absent or faint. This NLR is unlike any other NLR or extended emission line region known. Spectroscopy with Gemini/GMOS reveals extended, high-luminosity [O III] emission also in other GBs. WISE 24 {mu}m luminosities are 5-50 times lower than predicted by the [O III] fluxes, suggesting that the NLRs reflect earlier, very active quasar states that have strongly subsided in less than a galaxy's light-crossing time. These light echoes, or ionization echoes, are about 100 times more luminous than any other such echo known to date. X-ray data are needed for photoionization modeling and to verify the light echoes.

  20. 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.

  1. A Sample of Seyfert-2 Galaxies with Ultraluminous Galaxy-wide Narrow-line Regions: Quasar Light Echoes?

    NASA Astrophysics Data System (ADS)

    Schirmer, M.; Diaz, R.; Holhjem, K.; Levenson, N. A.; Winge, C.

    2013-01-01

    We report the discovery of Seyfert-2 galaxies in SDSS-DR8 with galaxy-wide, ultraluminous narrow-line regions (NLRs) at redshifts z = 0.2-0.6. With a space density of 4.4 Gpc-3 at z ~ 0.3, these "green beans" (GBs) are amongst the rarest objects in the universe. We are witnessing an exceptional and/or short-lived phenomenon in the life cycle of active galactic nuclei (AGNs). The main focus of this paper is on a detailed analysis of the GB prototype galaxy J2240-0927 (z = 0.326). Its NLR extends over 26 × 44 kpc and is surrounded by an extended NLR. With a total [O III] λ5008 luminosity of (5.7 ± 0.9) × 1043 erg s-1, this is one of the most luminous NLRs known around any type-2 galaxy. Using VLT/XSHOOTER, we show that the NLR is powered by an AGN, and we derive resolved extinction, density, and ionization maps. Gas kinematics is disturbed on a global scale, and high-velocity outflows are absent or faint. This NLR is unlike any other NLR or extended emission line region known. Spectroscopy with Gemini/GMOS reveals extended, high-luminosity [O III] emission also in other GBs. WISE 24 μm luminosities are 5-50 times lower than predicted by the [O III] fluxes, suggesting that the NLRs reflect earlier, very active quasar states that have strongly subsided in less than a galaxy's light-crossing time. These light echoes, or ionization echoes, are about 100 times more luminous than any other such echo known to date. X-ray data are needed for photoionization modeling and to verify the light echoes. Based on observations made with ESO Telescopes at the La Silla and Paranal Observatories, Chile. Based on observations obtained with MegaPrime/MegaCam, a joint project of CFHT and CEA/DAPNIA, at the Canada-France-Hawaii Telescope (CFHT), which is operated by the National Research Council (NRC) of Canada, the Institut National des Sciences de l'Univers of the Centre National de la Recherche Scientifique (CNRS) of France, and the University of Hawaii. Based on observations

  2. 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.

  3. A millimeter-wave survey of CO emission in Seyfert galaxies

    NASA Technical Reports Server (NTRS)

    Heckman, T. M.; Blitz, L.; Wilson, A. S.; Armus, L.; Miley, G. K.

    1989-01-01

    Emission in the 115 GHz 1-0 line of CO has been detected in 18 Seyfert galaxies in a sample of 43. The CO properties of 29 Seyferts in the Revised Shapley Ames Catalog (RSA) are compared with the CO properties of normal galaxies of the same Hubble type. These RSA type 2 Seyferts have an average ratio of CO-to-blue luminosity that is about twice as large as that of the normal galaxies, but the RSA type 1 Seyferts have normal CO luminosities. The RSA type 2 Seyfert galaxies have an unusually large average ratio of CO luminosity-to-H I mass compared to normal disk galaxies. The RSA type 2 Seyferts have an average far-IR luminosity that is about four times larger than a non-Seyfert comparison sample, while the RSA type 1 Seyferts are not significantly more luminous than the non-Seyferts. The result imply that the two classes of Seyferts are intrinsically different from one another and that one class cannot evolve into another in less than a few million years.

  4. Hα Imaging of Nearby Seyfert Host Galaxies

    NASA Astrophysics Data System (ADS)

    Theios, Rachel L.; Malkan, Matthew A.; Ross, Nathaniel R.

    2016-05-01

    We used narrowband (Δλ = 70 Å) interference filters with the CCD imaging camera on the Nickel 1.0 m telescope at Lick Observatory to observe 31 nearby (z < 0.03) Seyfert galaxies in the 12 μm active galaxy sample. We obtained pure emission-line images of each galaxy, which reach down to a flux limit of 7.3 × 10-15 erg cm-2 s-1 arcsec-2, and corrected these images for [N ii] emission and extinction. We separated the Hα emission line of the “nucleus” (central 100-1000 pc) from that of the host galaxy. The extended Hα emission is expected to be powered by newly formed hot stars, and indeed correlates well with other indicators of current star formation rates (SFRs) in these galaxies: extended 7.7 μm polycyclic aromatic hydrocarbon, total far-infrared, and radio luminosity. Relative to what would be expected from recent star formation, there is a 0.8 dex excess of radio emission in our Seyfert galaxies. The Hα luminosity we measured in the centers of our galaxies is dominated by the active galactic nucleus (AGN), and is linearly correlated with the hard X-ray luminosity. There is, however, an upward offset of 1 dex in this correlation for the Seyfert 1s, because their nuclear Hα emission includes a strong additional contribution from the broad-line region. We found a correlation between SFR and AGN luminosity. In spite of selection effects, we concluded that the absence of bright Seyfert nuclei in galaxies with low SFRs is real, albeit only weakly significant. Finally, we used our measured spatial distributions of Hα emission to determine what these Seyfert galaxies would look like when observed through fixed apertures (e.g., a spectroscopic fiber) at high redshifts. We found that although all of these Seyfert galaxies would be detectable emission-line galaxies at any redshift, most of them would appear to be dominated by (>67%) their H ii region emission. Only the most luminous AGNs (log(L Hα /erg s-1) > 41.5) would still be identified as such at z

  5. Hα Imaging of Nearby Seyfert Host Galaxies

    NASA Astrophysics Data System (ADS)

    Theios, Rachel L.; Malkan, Matthew A.; Ross, Nathaniel R.

    2016-05-01

    We used narrowband (Δλ = 70 Å) interference filters with the CCD imaging camera on the Nickel 1.0 m telescope at Lick Observatory to observe 31 nearby (z < 0.03) Seyfert galaxies in the 12 μm active galaxy sample. We obtained pure emission-line images of each galaxy, which reach down to a flux limit of 7.3 × 10‑15 erg cm‑2 s‑1 arcsec‑2, and corrected these images for [N ii] emission and extinction. We separated the Hα emission line of the “nucleus” (central 100–1000 pc) from that of the host galaxy. The extended Hα emission is expected to be powered by newly formed hot stars, and indeed correlates well with other indicators of current star formation rates (SFRs) in these galaxies: extended 7.7 μm polycyclic aromatic hydrocarbon, total far-infrared, and radio luminosity. Relative to what would be expected from recent star formation, there is a 0.8 dex excess of radio emission in our Seyfert galaxies. The Hα luminosity we measured in the centers of our galaxies is dominated by the active galactic nucleus (AGN), and is linearly correlated with the hard X-ray luminosity. There is, however, an upward offset of 1 dex in this correlation for the Seyfert 1s, because their nuclear Hα emission includes a strong additional contribution from the broad-line region. We found a correlation between SFR and AGN luminosity. In spite of selection effects, we concluded that the absence of bright Seyfert nuclei in galaxies with low SFRs is real, albeit only weakly significant. Finally, we used our measured spatial distributions of Hα emission to determine what these Seyfert galaxies would look like when observed through fixed apertures (e.g., a spectroscopic fiber) at high redshifts. We found that although all of these Seyfert galaxies would be detectable emission-line galaxies at any redshift, most of them would appear to be dominated by (>67%) their H ii region emission. Only the most luminous AGNs (log(L Hα /erg s‑1) > 41.5) would still be identified as

  6. Spectral characterization of igneous rocks in the 8- to 12-micron region

    NASA Technical Reports Server (NTRS)

    Walter, Louis S.; Salisbury, John W.

    1989-01-01

    This paper investigates the crystal-chemistry basis for the variation in spectral behavior of ingneous rocks, with the purpose of developing relationships useful for applications in the lithologic characterization of terrestrial and extraterrestrial surfaces. A new parameter is proposed for characterizing general rock and mineral type. The parameter, SCFM, defined as the ratio SiO2/(SiO2 + CaO + FeO + MgO), reflects the degree of depolymerization of the silica tetrahedra in both fine-grained and coarse-grained igneous rocks, and is a good descriptor of the composition of these rocks. Using spectra obtained in the laboratory on coarse-particulate mineral and solid-rock samples, the SCFM parameter was used to assess the effects of variations in the rock composition on the location, number, and width of spectral bands. A regression analysis of bands varying in width from 0.2 micron to 1.4 microns versus the SCFM value resulted in correlation coefficients ranging from 0.88 to 0.97.

  7. Constraining the Active Galactic Nucleus Contribution in a Multiwavelength Study of Seyfert Galaxies

    NASA Technical Reports Server (NTRS)

    Melendez, M.; Kraemer, S.B.; Schmitt, H.R.; Crenshaw, D.M.; Deo, R.P.; Mushotzky, R.F.; Bruhweiler, F.C.

    2008-01-01

    We have studied the relationship between the high- and low-ionization [O IV] (lambda)25.89 microns, [Ne III] (lambda)15.56 microns, and [Ne II] (lambda)12.81 microns emission lines with the aim of constraining the active galactic nuclei (AGNs) and star formation contributions for a sample of 103 Seyfert galaxies.We use the [O IV] and [Ne II] emission as tracers for the AGN power and star formation to investigate the ionization state of the emission-line gas.We find that Seyfert 2 galaxies have, on average, lower [O IV]/[Ne II] ratios than Seyfert 1 galaxies. This result suggests two possible scenarios: (1) Seyfert 2 galaxies have intrinsically weaker AGNs, or (2) Seyfert 2 galaxies have relatively higher star formation rates than Seyfert 1 galaxies. We estimate the fraction of [Ne II] directly associated with the AGNs and find that Seyfert 2 galaxies have a larger contribution from star formation, by a factor of approx.1.5 on average, than what is found in Seyfert 1 galaxies. Using the stellar component of [Ne II] as a tracer of the current star formation, we found similar star formation rates in Seyfert 1 and Seyfert 2 galaxies.We examined the mid- and far-infrared continua and found that [Ne II] is well correlated with the continuum luminosity at 60 microns and that both [Ne III] and [O IV] are better correlated with the 25 micron luminosities than with the continuum at longer wavelengths, suggesting that the mid-infrared continuum luminosity is dominated by the AGN, while the far-infrared luminosity is dominated by star formation. Overall, these results test the unified model of AGNs and suggest that the differences between Seyfert galaxies cannot be solely due to viewing angle dependence.

  8. The Non-Stellar Infrared Continuum of Seyfert Galaxies

    NASA Technical Reports Server (NTRS)

    Alonso-Herrero, Almudena; Quillen, Alice C.; Simpson, Chris; Efstathiou, Andreas; Ward, Martin J.

    2000-01-01

    JHKL'M (1 - 5 micrometers) imaging of a sample of Seyfert 2 galaxies is presented. We have performed an accurate estimate of the near-infrared non-stellar nuclear fluxes. We confirm that the near-infrared nuclear continuum between 1 and 2.2microns of some Seyfert 2s is dominated by stellar emission, whereas the continuum emission at longer wavelengths (lambda = 3 - 5 micrometers) is almost entirely non-stellar in origin. The non-stellar spectral energy distributions (SED) in the infrared (up to 15 micrometers) of Seyfert galaxies show a variety of shapes, and they are well reproduced with the tapered disk models of Efstathiou & Rowan-Robinson (1995). We have used two models, one including an optically thin cone component found to fit the SED of NGC 1068, and a coneless model. Although our modelling of the SEDs does not allow us to favor either model to account for all the observed SEDs, we find that the viewing angle towards the central source is well constrained by both models. The galaxies in our sample have fitted values of the viewing angle in the range Theta(sub V) = 0 deg - 64 deg, for the assumed model parameters. We have also investigated non-stellar color-color diagrams (L' - M vs. H - M and L' - M vs. H - L'). The colors of the Seyfert galaxies with viewing angles Theta(sub v) less than 30 deg are better reproduced with the cone model. These diagrams provide a good means to separate Seyfert 2s with moderate obscuration (A(sub V) approx. less than 20 mag from hard X-ray observations) from those with high obscuration. The ground-based 4.8 microns and ISO 9.6 microns luminosities are well correlated with the hard X-ray luminosities of Seyfert ls and 2s. These continuum emissions appear as a good indicator of the AGN luminosity, at least in the cases of hard X-ray Compton-thin Seyfert galaxies (N(sub H) less than or = 10(exp 24)/sq cm). We finally stress the finding that some Compton thick galaxies show bright non-stellar emission at 5 microns This suggests

  9. Visible and Near-Infrared Spectroscopy of Seyfert 1 and Narrow-Line Seyfert 1 Galaxies

    NASA Astrophysics Data System (ADS)

    Rodríguez-Ardila, Alberto; Pastoriza, Miriani G.; Donzelli, Carlos J.

    2000-01-01

    This paper studies the continuum and emission-line properties of a sample composed of 16 normal Seyfert 1 and seven narrow-line Seyfert 1 (NLS1) galaxies using optical and near-IR CCD spectroscopy. The continuum emission of the galaxies can be described in terms of a combination of stellar population, a nonstellar continuum of power-law form, and Fe II emission. A significative difference in the optical spectral index between NLS1's and normal Seyfert 1's is observed; the latter is steeper. Most NLS1's show Fe II/Hβ ratios larger than those observed in the other Seyfert 1's. In the IRAS band, both groups of galaxies have very similar properties. We have searched for the presence of optically thin gas in the broad-line region (BLR) of the galaxies by comparing the broad O I λ8446 and Hα emission-line profiles. Our analysis show that in the NLS1's, both profiles are similar in shape and width. This result contradicts the hypothesis of thin gas emission in the high-velocity part of the BLR to explain the ``narrowness'' of broad optical permitted lines in these objects. Evidence of narrow O I λ8446 emission is found in six galaxies of our sample, implying that this line is not restricted to a pure BLR phenomenon. In the narrow-line region, we find similar luminosities in the permitted and high-ionization lines of NLS1's and normal Seyfert 1's. However, low-ionization lines such as [O I] λ6300, [O II] λ3727, and [S II] λλ6717, 6731 are intrinsically less luminous in NLS1's. Physical properties derived from density- and temperature-sensitive line ratios suggest that the [O II] and [S II] emitting zones are overlapping in normal Seyfert 1's and separated in NLS1's. Based on observations made at CASLEO. Complejo Astronómico El Leoncito (CASLEO) is operated under agreement between the Consejo Nacional de Investigaciones Científicas y técnicas de la República Argentina and the National Universities of La Plata, Córdoba and San Juán.

  10. Low-level water vapor fields from the VAS split-window channels at 11 and 12 microns

    NASA Technical Reports Server (NTRS)

    Chesters, D.; Uccellini, L. W.; Robinson, W.

    1983-01-01

    Originally, the VAS split window channels were designed to use the differential water vapor absorption between 11 and 12 microns to estimate sea surface temperature by correcting for the radiometric losses caused by atmospheric moisture. It is shown that it is possible to reverse the procedure in order to estimate the vertically integrated low level moisture content with the background surface (skin) temperature removed, even over the bright, complex background of the land. Because the lower troposphere's water vapor content is an important factor in convective instability, the derived fields are of considerable value to mesoscale meteorology. Moisture patterns are available as quantitative fields (centimeters of precipitable water) at full VAS resolution (as fine as 7 kilometers horizontal resolution every 15 minutes), and are readily converted to image format for false color movies. The technique, demonstrated with GOES-5, uses a sequence of split window radiances taken once every 3 hours from dawn to dusk over the Eastern and Central United States. The algorithm is calibrated with the morning radiosonde sites embedded within the first VAS radiance field; then, entire moisture fields are calculated at all five observation times. Cloud contamination is removed by rejecting any pixel having a radiance less than the atmospheric brightness determined at the radiosonde sites.

  11. 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.

  12. THE DIFFERENCE IN NARROW Fe K{alpha} LINE EMISSION BETWEEN SEYFERT 1 AND SEYFERT 2 GALAXIES

    SciTech Connect

    Liu Teng; Wang Junxian E-mail: jxw@ustc.edu.c

    2010-12-20

    We compile a sample of 89 Seyfert galaxies with both [O IV] 25.89 {mu}m line luminosities observed by Spitzer IRS and X-ray spectra observed by XMM-Newton EPIC. Using [O IV] emission as a proxy for active galactic nucleus (AGN) intrinsic luminosity, we find that although type 2 AGNs have higher line equivalent widths, the narrow Fe K{alpha} lines in Compton-thin and Compton-thick Seyfert 2 galaxies are 2.9{sup +0.8}{sub -0.6} and 5.6{sup +1.9}{sub -1.4} times weaker in terms of luminosity than Seyfert 1 galaxies, respectively. This indicates that different correction factors need to be applied for various types of AGNs before the narrow Fe K{alpha} line luminosity could serve as an intrinsic AGN luminosity indicator. We also find that Seyfert 1 galaxies in our sample have on average marginally larger line widths and higher line centroid energies, suggesting contamination from highly ionized Fe line or broader line emission from much smaller radius, but this effect is too weak to explain the large difference in narrow Fe K{alpha} line luminosity between type 1 and type 2 AGNs. This is the first observational evidence showing that the narrow Fe K{alpha} line emission in AGNs is anisotropic. The observed difference is consistent with theoretical calculations assuming a smoothly distributed obscuring torus and could provide independent constraints on the clumpiness of the torus.

  13. Surface-induced brightness temperature variations and their effects on detecting thin cirrus clouds using IR emission channels in the 8-12 microns region

    NASA Technical Reports Server (NTRS)

    Gao, Bo-Cai; Wiscombe, W. J.

    1994-01-01

    A method for detecting cirrus clouds in terms of brightness temperature differences between narrowbands at 8, 11, and 12 microns has been proposed by Ackerman et al. In this method, the variation of emissivity with wavelength for different surface targets was not taken into consideration. Based on state-of-the-art laboratory measurements of reflectance spectra of terrestrial materials by Salisbury and D'Aria, it is found that the brightness temperature differences between the 8- and 11-microns bands for soils, rocks, and minerals, and dry vegetation can vary between approximately -8 and +8 K due solely to surface emissivity variations. The large brightness temperature differences are sufficient to cause false detection of cirrus clouds from remote sensing data acquired over certain surface targets using the 8-11-12-microns method directly. It is suggested that the 8-11-12-microns method should be improved to include the surface emissivity effects. In addition, it is recommended that in the future the variation of surface emissivity with wavelength should be taken into account in algorithms for retrieving surface temperatures and low-level atmospheric temperature and water vapor profiles.

  14. Hot coronae in nearby Seyfert galaxies

    NASA Astrophysics Data System (ADS)

    Tortosa, Alessia

    2016-08-01

    The primary X-ray emission in AGN is believed to be produced by Comptonization of optical/UV disk photons scattered up to the X-ray band by a hot corona located above the accretion disk. The emitted spectrum is, at the first order, a power-law with a high-energy cutoff, where the photon index and the cutoff energy are directly related to the temperature and to the optical depth of the plasma of hot electrons responsible for the inverse Compton scattering.To investigate the physical properties of the corona and provide constraints on its parameters, we have studied the broad band spectra of a sample of local Seyfert galaxies observed with NuSTAR (in coordination with XMM-Newton, Suzaku or Swift). We will discuss the general properties of the sample, and show a few particularly interesting cases.

  15. A demonstration of CMOS VLSI circuit prototyping in support of the site facility using the 1.2 micron standard cell library developed by National Security Agency

    NASA Astrophysics Data System (ADS)

    Smith, Edwyn D.

    1991-03-01

    Two silicon CMOS application specific integrated circuits (ASICs), a data generation chip, and a data checker chip were designed. The conversion of the data generator circuitry into a pair of CMOS ASIC chips using the 1.2 micron standard cell library is documented. The logic design of the data checker is discussed. The functions of the control circuitry is described. An accurate estimate of timing relationships is essential to make sure that the logic design performs correctly under practical conditions. Timing and delay information are examined.

  16. A demonstration of CMOS VLSI circuit prototyping in support of the site facility using the 1.2 micron standard cell library developed by National Security Agency

    NASA Technical Reports Server (NTRS)

    Smith, Edwyn D.

    1991-01-01

    Two silicon CMOS application specific integrated circuits (ASICs), a data generation chip, and a data checker chip were designed. The conversion of the data generator circuitry into a pair of CMOS ASIC chips using the 1.2 micron standard cell library is documented. The logic design of the data checker is discussed. The functions of the control circuitry is described. An accurate estimate of timing relationships is essential to make sure that the logic design performs correctly under practical conditions. Timing and delay information are examined.

  17. Diffuse emission and pathological Seyfert spectra

    NASA Technical Reports Server (NTRS)

    Halpern, Jules P.

    1995-01-01

    In this annual ROSAT status report, the diffuse emission and spectra from Seyfert galaxies are examined. Three papers are presented and their contents include the soft x-ray properties and spectra of a binary millisecond pulsar, the PSPC and HRI observations of a Starburst/Seyfert 2 Galaxy, and an analysis of the possibility of x-ray luminous starbursts in the Einstein Medium Sensitivity Survey.

  18. Low-level water vapor fields from the VISSR atmospheric sounder (VAS) split window channels at 11 and 12 microns. [visible infrared spin scan radiometer

    NASA Technical Reports Server (NTRS)

    Chesters, D.; Uccellini, L.; Robinson, W.

    1982-01-01

    A series of high-resolution water vapor fields were derived from the 11 and 12 micron channels of the VISSR Atmospheric Sounder (VAS) on GOES-5. The low-level tropospheric moisture content was separated from the surface and atmospheric radiances by using the differential adsorption across the 'split window' along with the average air temperature from imbedded radiosondes. Fields of precipitable water are presented in a time sequence of five false color images taken over the United States at 3-hour intervals. Vivid subsynoptic and mesoscale patterns evolve at 15 km horizontal resolution over the 12-hour observing period. Convective cloud formations develop from several areas of enhanced low-level water vapor, especially where the vertical water vapor gradient relatively strong. Independent verification at radiosonde sites indicates fairly good absolute accuracy, and the spatial and temporal continuity of the water vapor features indicates very good relative accuracy. Residual errors are dominated by radiometer noise and unresolved clouds.

  19. Is the cluster environment quenching the Seyfert activity in elliptical and spiral galaxies?

    NASA Astrophysics Data System (ADS)

    de Souza, R. S.; Dantas, M. L. L.; Krone-Martins, A.; Cameron, E.; Coelho, P.; Hattab, M. W.; de Val-Borro, M.; Hilbe, J. M.; Elliott, J.; Hagen, A.; COIN Collaboration

    2016-09-01

    We developed a hierarchical Bayesian model (HBM) to investigate how the presence of Seyfert activity relates to their environment, herein represented by the galaxy cluster mass, M200, and the normalized cluster centric distance, r/r200. We achieved this by constructing an unbiased sample of galaxies from the Sloan Digital Sky Survey, with morphological classifications provided by the Galaxy Zoo Project. A propensity score matching approach is introduced to control the effects of confounding variables: stellar mass, galaxy colour, and star formation rate. The connection between Seyfert-activity and environmental properties in the de-biased sample is modelled within an HBM framework using the so-called logistic regression technique, suitable for the analysis of binary data (e.g. whether or not a galaxy hosts an AGN). Unlike standard ordinary least square fitting methods, our methodology naturally allows modelling the probability of Seyfert-AGN activity in galaxies on their natural scale, i.e. as a binary variable. Furthermore, we demonstrate how an HBM can incorporate information of each particular galaxy morphological type in an unified framework. In elliptical galaxies our analysis indicates a strong correlation of Seyfert-AGN activity with r/r200, and a weaker correlation with the mass of the host cluster. In spiral galaxies these trends do not appear, suggesting that the link between Seyfert activity and the properties of spiral galaxies are independent of the environment.

  20. The Variability of Seyfert 1.8 and 1.9 Galaxies at 1.6 Microns.

    PubMed

    Quillen; Shaked; Alonso-Herrero; McDonald; Lee; Rieke; Rieke

    2000-03-20

    We present a study of Seyfert 1.5-2.0 galaxies observed at two epochs with the Hubble Space Telescope (HST) at 1.6 µm. We find that unresolved nuclear emission from nine of 14 nuclei varies at the level of 10%-40% on timescales of 0.7-14 months, depending upon the galaxy. A control sample of Seyfert galaxies lacking unresolved sources and galaxies lacking Seyfert nuclei show less than 3% instrumental variation in equivalent aperture measurements. This proves that the unresolved sources are nonstellar and associated with the central parsecs of active galactic nuclei. Unresolved sources in Seyfert 1.8 and 1.9 galaxies are not usually detected in HST optical surveys; however, high angular resolution infrared observations will provide a way to measure time delays in these galaxies. PMID:10702122

  1. Hard X-ray emission from a type 2 Seyfert galaxy (NGC 1068)

    NASA Technical Reports Server (NTRS)

    Elvis, Martin; Lawrence, A.

    1988-01-01

    Exosat observations of the type 2 Seyfert galaxy NGC 1068 have detected a source in the 2-10 KeV range with a flux density at 2 keV of 0.6 micron-Jy. It has a flat power-law spectrum similar to type 1 Seyferts. Combined with Low Energy Exosat filter data and Einstein IPC observations, these data show that spectral curvature is necessary, flattening the X-ray spectrum to high energies. The spectrum can be decomposed into two components: a steep low-energy part and a flat high-energy part. Any intrinsic absorption is small. There is no evidence for variability within or between any of the observations, which sample time scales from 30 minutes to 4 yr. These data support the 'obscuration' model of type 2 Seyfert galaxies in which the nucleus is seen only in flux scattered from above a 'wall' of material that completely blocks the direct view.

  2. X-ray Emission from Seyfert 2 Galaxies with Low-Mass Black Holes

    NASA Astrophysics Data System (ADS)

    Barth, Aaron

    2005-10-01

    We have recently identified the first sample of Seyfert 2 nuclei in host galaxies with stellar velocity dispersions smaller than 60 km/s, as a way to detect and study black holes with likely masses below 10^6 solar masses. These galaxies are Type 2 analogs of "dwarf" Seyfert 1 galaxies such as NGC 4395 and POX 52. We propose to obtain XMM exposures of four Seyfert 2 galaxies with stellar velocity dispersions in the range 25-47 km/s in order to (a) determine X-ray luminosities as part of an overall program to measure the SEDs of these sources; (b) determine the amount of X-ray absorption to establish whether these are obscured versions of NLS1 galaxies; (c) search for variability, which is expected for AGNs with very low black hole masses.

  3. Far-ultraviolet and optical spectrophotometry of X-ray selected Seyfert galaxies

    NASA Technical Reports Server (NTRS)

    Clarke, J. T.; Bowyer, S.; Grewing, M.

    1986-01-01

    Five X-ray selected Seyfert galaxies were examined via near-simultaneous far-ultraviolet and optical spectrophotometry in an effort to test models for excitation of emission lines by X-ray and ultraviolet continuum photoionization. The observed Ly-alpha/H-beta ratio in the present sample averages 22, with an increase found toward the high-velocity wings of the H lines in the spectrum of at least one of the Seyfert I nuclei. It is suggested that Seyfert galaxies with the most high-velocity gas exhibit the highest Ly-alpha/H-beta ratios at all velocities in the line profiles, and that sometimes this ratio may be highest for the highest velocity material in the broad-line clouds. Since broad-lined objects are least affected by Ly-alpha trapping effects, they have Ly-alpha/H-beta ratios much closer to those predicted by early photoionization calculations.

  4. The Role of Environment in Fueling Seyfert AGN

    NASA Astrophysics Data System (ADS)

    Hicks, Erin Kathleen Strobel

    2015-08-01

    We consider the role of environment in fueling of Seyfert AGN through a combined analysis of Hubble Space Telescope images and integral field spectroscopy of the ISM in a sample of local AGN. Using visible and near-infrared Hubble Space Telescope images and color maps of over a 100 galaxies we determine the distribution of the cold ISM, as traced by dust. We also measure the two-dimensional distribution and kinematics of the molecular gas, traced by H2 1-0 S(1) emission at 2.12 μm, down to scales of tens of parsecs using OSIRIS at Keck and SINFONI on VLT for a subset of approximately 20 of these galaxies. Informed by these kinematic measurements of the ISM we classify the nuclear dust morphologies of the full sample of galaxies and interpret the significance of these morphologies in terms of inflow. Our relatively small precursor sample (Hicks et al. 2009, Davies et al. 2014) hinted at a connection between the host galaxy environment and the primary mechanism driving gas inward such that fueling of AGN in isolated galaxies occurs primarily via secular processes (e.g. nuclear spirals) and galaxies in groups of 10-15 members via accretion of external gas. Using our expanded sample that now has the ability to reveal statistically significant trends we explore the potential influence of the galaxy environment on the fueling of Seyfert AGN.

  5. Study of Milli-Jansky Seyfert Galaxies with Strong Forbidden High-Ionization Lines Using the Very Large Array Survey Images

    NASA Astrophysics Data System (ADS)

    Lal, Dharam V.

    2015-12-01

    We study the radio properties at 1.4 GHz of Seyfert galaxies with strong forbidden high-ionization lines (FHILs), selected from the Sloan Digital Sky Survey - a large-sized sample containing nearly equal proportion of diverse range of Seyfert galaxies showing similar redshift distributions compiled by tet{GMW2009} using the Very Large Array survey images. The radio detection rate is low, 49%, which is lower than the detection rate of several other known Seyfert galaxy samples. These galaxies show low star formation rates and the radio emission is dominated by the active nucleus with ≤10% contribution from thermal emission, and possibly, none show evidence for relativistic beaming. The radio detection rate, distributions of radio power, and correlations between radio power and line luminosities or X-ray luminosity for narrow-line Seyfert 1 (NLS1), Seyfert 1 and Seyfert 2 galaxies are consistent with the predictions of the unified scheme hypothesis. Using correlation between radio and [O III] λ 5007 Å luminosities, we show that ˜8% sample sources are radio-intermediate and the remaining are radio-quiet. There is possibly an ionization stratification associated with clouds on scales of 0.1-1.0 kpc, which have large optical depths at 1.4 GHz, and it seems these clouds are responsible for free-free absorption of radio emission from the core; hence, leading to low radio detection rate for these FHIL-emitting Seyfert galaxies.

  6. Nuevas Galaxias Seyfert 1 Australes

    NASA Astrophysics Data System (ADS)

    Maza, J.; Ruiz, M. T.

    1987-05-01

    En 1984 se inició una extensión del "survey" de Tololo que de- sarrollara en 1975 Smith, con la cámara Curtis-Schmidt y el prisma UV delgado. Utilizando placas IIIaJ horneadas, sin filtro, expues tas 90 minutos sin ensanchamiento se han obtenido a la fecha más de 150 placas que cubren la zona entre -20° y -45° a latitudes galácticas mayores de 20°; se presenta un detalle de las franjas que comprende el survey Calan-Tololo, indicando el grado de completitud de las mismas. Se ha encontrado un gran número de galaxias con líneas de emisión entre las cuales las más frecuentes, más de 300, son galaxias irregulares con formación estelar violenta ("starburst galaxies"). Se ha encontrado un número de cuasares cercano a 100; casi todos ellos tienen la linea Lyman alfa en la zona entre 3300 y 5300 A, que corresponde a un rango de corrimientosal rojo 1.7< z <3.3 el cuasar con mayor corri- miento al rojo encontrado a la fecha en el survey tiene z = 3.1. La información detallada sobre cuasares y galaxias tipo "starburst" será presentada en otro lugar. Entre los objetos más interesantes encontrados en el survey Calán- Tololo destacan unas 50 nuevas galaxias Seyfert 1. Estas galaxias han sido encontradas por su fuerte exceso UV y su brillante núcleo, más que por sus intensas lineas de emisión. Hemos observado espectroscópicamente, en el Observatorio Interamericano de Cerro Tololo, 37 de ellas para las cuales se presentan cartas de identificación, coordenadas y los datos espectroscópicos obtenidos.

  7. Long-term infrared photometry of Seyferts

    NASA Astrophysics Data System (ADS)

    Glass, I. S.

    2004-05-01

    Long-term (up to 10 000 d) monitoring has been undertaken for 41 Seyferts in the near-infrared (1.25-3.45 μm). All but two showed variability, with amplitudes at K in the range <0.1 to >1.1 mag. The time-scale for detectable change is from about one week to a few years. Where contemporary observations of variability in X-rays, ultraviolet (UV) or visible light exist, it is found that the near-infrared varies in a similar way, though in some cases the shorter-wavelength infrared (IR) bands are diluted by underlying galaxy radiation. A simple cross-correlation study indicates that there is evidence for delays of up to several hundred d between the variations seen at the shortest wavelengths (U or J) and the longest (L) in many galaxies. In particular, the data for Fairall 9 now extend to twice the interval covered in earlier publications and the delay between its UV and IR outputs is seen to persist. An analysis of the fluxes shows that, for any given galaxy, the colours of the variable component of its nucleus are usually independent of the level of activity. The state of activity of the galaxy can be parameterized. Taken over the whole sample, the colours of the variable components fall within moderately narrow ranges. In particular, the H-K colour is appropriate to a blackbody of temperature 1600 K. The H-K excess for a heavily reddened nucleus can be determined and used to find EB-V, which can be compared to the values found from the visible region broad line ratios. Using flux-flux diagrams, the flux within the aperture from the underlying galaxies can often be determined without the need for model surface brightness profiles. In many galaxies it is apparent that there must be an additional constant contribution from warm dust.

  8. Narrow-Line Seyfert 1 Galaxies

    NASA Technical Reports Server (NTRS)

    Leighly, Karen M.

    2000-01-01

    The primary work during this year has been the analysis and interpretation of our HST spectra from two extreme Narrow-line Seyfert 1 galaxies (NLS1s) Infrared Astronomy Satellite (IRAS) 13224-3809 and 1H 0707-495. This work has been presented as an invited talk at the workshop entitled "Observational and theoretical progress in the Study of Narrow-line Seyfert 1 Galaxies" held in Bad Honnef, Germany December 8-11, as a contributed talk at the January 2000 AAS meeting in Atlanta, Georgia, and as a contributed talk at the workshop "Probing the Physics of Active Galactic Nuclei by Multiwavelength Monitoring" held at Goddard Space Flight Center June 20-22, 2000.

  9. Giant Broad Line Regions in Dwarf Seyferts

    NASA Astrophysics Data System (ADS)

    Devereux, Nick

    2015-12-01

    High angular resolution spectroscopy obtained with the Hubble Space Telescope (HST) has revealed a remarkable population of galaxies hosting dwarf Seyfert nuclei with an unusually large broad-line region (BLR). These objects are remarkable for two reasons. Firstly, the size of the BLR can, in some cases, rival those seen in the most luminous quasars. Secondly, the size of the BLR is not correlated with the central continuum luminosity, an observation that distinguishes them from their reverberating counterparts. Collectively, these early results suggest that non-reverberating dwarf Seyferts are a heterogeneous group, and not simply scaled versions of each other. Careful inspection reveals broad H Balmer emission lines with single peaks, double peaks, and a combination of the two, suggesting that the broad emission lines are produced in kinematically distinct regions centered on the black hole (BH). Because the gravitational field strength is already known for these objects, by virtue of knowing their BH mass, the relationship between velocity and radius may be established, given a kinematic model for the BLR gas. In this way, one can determine the inner and outer radii of the BLRs by modeling the shape of their broad emission line profiles. In the present contribution, high quality spectra obtained with the Space Telescope Imaging Spectrograph (STIS) are used to constrain the size of the BLR in the dwarf Seyfert nuclei of M81, NGC 3998, NGC 4203, NGC 3227, NGC 4051 and NGC 3516.

  10. Giant Broad Line Regions in Dwarf Seyferts

    NASA Astrophysics Data System (ADS)

    Devereux, Nicholas A.

    2016-01-01

    High angular resolution spectroscopy obtained with the Hubble Space Telescope has revealed a remarkable population of galaxies hosting dwarf Seyfert nuclei with an unusually large broad-line region (BLR). These objects are remarkable for two reasons. Firstly, the size of the BLR can, in some cases, rival those seen in the most luminous quasars. Secondly, the size of the BLR is not correlated with the central continuum luminosity, an observation that distinguishes them from their reverberating counterparts. Collectively, these early results suggest that non-reverberating dwarf Seyferts are a heterogeneous group and not simply scaled versions of each other. Careful inspection reveals broad H Balmer emission lines with single peaks, double peaks, and a combination of the two, suggesting that the broad emission lines are produced in kinematically distinct regions centered on the black hole (BH). Because the gravitational field strength is already known for these objects, by virtue of knowing their BH mass, the relationship between velocity and radius may be established, given a kinematic model for the BLR gas. In this way, one can determine the inner and outer radii of the BLRs by modeling the shape of their broad emission line profiles. In the present contribution, high quality spectra obtained with the Space Telescope Imaging Spectrograph are used to constrain the size of the BLR in the dwarf Seyfert nuclei of M81, NGC 3998, NGC 4203, NGC 3227, NGC 4051, and NGC 3516.

  11. Kiloparsec-scale radio emission in Seyfert and LINER galaxies

    NASA Astrophysics Data System (ADS)

    Singh, Veeresh; Ishwara-Chandra, C. H.; Wadadekar, Yogesh; Beelen, Alexandre; Kharb, Preeti

    2015-01-01

    Seyfert and LINER galaxies are known to exhibit compact radio emission on ˜10-100 pc scales, but larger Kiloparsec-Scale Radio structures (KSRs) often remain undetected in sub-arcsec high-resolution observations. We investigate the prevalence and nature of KSRs in Seyfert and LINER galaxies using the 1.4 GHz VLA FIRST and NVSS observations. Our sample consists of 2651 sources detected in FIRST and of these 1737 sources also have NVSS counterparts. Considering the ratio of total to peak flux density (θ = (Sint/Speak)1/2) as a parameter to infer the presence of extended radio emission we show that ≥30 per cent of FIRST-detected sources possess extended radio structures on scales larger than 1.0 kpc. The use of low-resolution NVSS observations help us to recover faint extended KSRs that are resolved out in FIRST observations and results in ≥42.5 per cent KSR sources in FIRST-NVSS sub-sample. This fraction is only a lower limit owing to the combination of projection, resolution and sensitivity effects. Our study demonstrates that KSRs may be more common than previously thought and are found across all redshifts, luminosities and radio loudness. The extranuclear radio luminosity of KSR sources is found to be positively correlated with the core radio luminosity as well as the [O III] λ5007 Å line luminosity and this can be interpreted as KSRs being powered by AGN rather than star formation. The distributions of the FIR-to-radio ratios and mid-IR colours of KSR sources are also consistent with their AGN origin. However, contribution from star formation cannot be ruled out particularly in sources with low radio luminosities.

  12. Optical, near, infrared and ultraviolet monitoring of the Seyfert 1 galaxy Markarian 335

    NASA Technical Reports Server (NTRS)

    Shrader, Chris R.; Sun, W.-H.; Turner, T. J.; Hintzen, P. M.

    1990-01-01

    Preliminary results of a multifrequency monitoring campaign for the bright, Seyfert 1 galactic nuclei Mkn335 are presented. Nearly uniform sampling at 3 day intervals is achieved quasi simultaneously at each wavelength band. Wavelength dependent variability is seen at the 20 to 30 percent level. Interpretation of variability in terms of geometrically thin, optically thick accretion disk models is discussed. The inferred blackhole masses and accretion rates are discussed. Possible correlation between continuum and emission line variations is discussed.

  13. VizieR Online Data Catalog: Atlas of HST STIS spectra of Seyfert galaxies (Spinelli+, 2006)

    NASA Astrophysics Data System (ADS)

    Spinelli, P. F.; Storchi-Bergmann, T.; Brandt, C. H.; Calzetti, D.

    2008-05-01

    We present a compilation of spectra of 101 Seyfert galaxies obtained with the Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS), covering the UV and/or optical spectral range. Information on all the available spectra have been collected in a Mastertable, which is a very useful tool for anyone interested in a quick glance at the existent STIS spectra for Seyfert galaxies in the HST archive, and it can be recovered electronically. Nuclear spectra of the galaxies have been extracted in windows of 0.2" for an optimized sampling (as this is the slit width in most cases) and combined in order to improve the signal-to-noise ratio and provide the widest possible wavelength coverage. These combined spectra are also available electronically, at http://www.if.ufrgs.br/~pat/atlas.htm . (3 data files).

  14. Was 49: Mirror for a hidden Seyfert 1 galaxy

    NASA Technical Reports Server (NTRS)

    Halpern, Jules; Moran, E.; Kay, L.; Antonucci, R.

    1993-01-01

    Was 49 is an interacting pair of Seyfert galaxies at z = 0.063, one of which contains a hidden Seyfert 1 nucleus as evidenced by the highly polarized broad wings on its Balmer lines. The disk of the main galaxy, Was 49a, appears to be globally photoionized by a powerful continuum source, undoubtedly the hidden Seyfert 1 companion, Was 49b. The intrinsic luminosity of Was 49b is at least 100 times larger than the observed (scattered) luminosity. A single SWP spectrum of the pair, which can be spatially resolved in the large aperture was obtained. A narrow Ly-alpha line was detected from Was 49b, the hidden Seyfert 1, at a flux level consistent with that of an unreddened Seyfert 2 galaxy. The lack of detection of a continuum is consistent with a power-law of v(sup -1) or steeper extrapolated from the optical, again consistent with the spectrum of other Seyfert 2 and hidden Seyfert 1 galaxies.

  15. Hubble Space Telescope Observations of the CFA Seyfert 2 Galaxies: The Fueling of Active Galactic Nuclei

    NASA Astrophysics Data System (ADS)

    Martini, Paul; Pogge, Richard W.

    1999-12-01

    We present an investigation of possible fueling mechanisms operating in the inner kiloparsec of Seyfert galaxies. We analyze visible and near-infrared Hubble Space Telescope images of 24 Seyfert 2 galaxies from the CfA Redshift Survey sample. In particular, we are searching for the morphological signatures of dynamical processes responsible for transporting gas from kiloparsec scales into the nucleus. The circumnuclear regions are very rich in gas and dust, often taking the form of nuclear spiral dust lanes on scales of a few hundred parsecs. While these nuclear spirals are found in 20 of our 24 Seyfert galaxies, we find only five nuclear bars among the entire sample, strongly reinforcing the conclusions of other investigators that nuclear bars are not the primary means of transporting this material into the nucleus. An estimate of the gas density in the nuclear spirals, based on extinction measurements, suggests that the nuclear spiral dust lanes are probably shocks in nuclear gas disks that are not strongly self-gravitating. Since shocks can dissipate energy and angular momentum, these spiral dust lanes may be the channels by which gas from the host galaxy disks is being fed into the central engines.

  16. The Seyfert-Starburst Connection in X-rays. 2; Results and Implications

    NASA Technical Reports Server (NTRS)

    Levenson, N. A.; Weaver, K. A.; Heckman, T. M.; White, Nicholas E. (Technical Monitor)

    2001-01-01

    We present the results of X-ray imaging and spectroscopic analysis of a sample of Seyfert 2 galaxies that contain starbursts, based on their optical and UV characteristics. These composite galaxies exhibit extended, soft, thermal X-ray emission, which we attribute to their starburst components. Comparing their X-ray and far-infrared properties with ordinary Seyfert and starburst galaxies, we identify the spectral characteristics of their various intrinsic emission sources. The observed far-infrared emission of the composite galaxies may be associated almost exclusively with star formation, rather than the active nucleus. The ratio of the hard X-ray luminosity to the far-infrared and [O III] (lambda)5007 luminosity distinguishes most of these composite galaxies from "pure" Seyfert 2 galaxies, while their total observed hard X-ray luminosity distinguishes them from "pure" starbursts. The hard nuclear X-ray source is generally heavily absorbed (N(sub H) greater than 10(exp 23)/sq cm) in the composite galaxies. Based on these results, we suggest that the interstellar medium of the nuclear starburst is a significant source of absorption. The majority of the sample are located in groups or are interacting with other galaxies, which may trigger the starburst or allow rapid mass infall to the central black hole or both. We conclude that starbursts are energetically important in a significant fraction of active galaxies and that starbursts and active galactic nuclei may be part of a common evolutionary sequence.

  17. High resolution CO images of Seyfert Galaxies

    NASA Technical Reports Server (NTRS)

    Meixner, M.; Puchalsky, R.; Blitz, L.; Wright, M.

    1990-01-01

    The CO (J = 1-0) emission of three Seyfert galaxies, NGC 3227, NGC 7469, and NGC 5033 was imaged. The CO emission in NGC 3227 and NGC 7469 appears as compact structures centered on the active nuclei, containing substantial fractions of the single-dish flux. In NGC 3227, 10 percent of the CO flux detected by the interferometer is contained within the ionized narrow-line region. The unresolved molecular gas concentrations in the nucleus of NGC 3227 imply a CO mass of 65 million solar masses concentrated within a diameter less than 50 pc. The CO emission in NGC 5033 is not detected at this resolution, implying a CO structure size of 20 to 60 arcsec. Continuum emission at 2.7 mm is not detected in any of the three galaxies. In the center of NGC 7469, the H2 mass is comparable to the dynamical mass. Kinematic studies of the detected gas reveal a rotational motion of the gas in NGC 3227 and NGC 7469, allowing identification of the gas in NGC 7469 with a nuclear starburst. These data are consistent with the idea that interactions between galaxies cause gas to concentrate in their nuclei thereby feeding starburst and Seyfert activity.

  18. Mid-infrared interferometry of Seyfert galaxies: Challenging the Standard Model

    NASA Astrophysics Data System (ADS)

    López-Gonzaga, N.; Jaffe, W.

    2016-06-01

    Aims: We aim to find torus models that explain the observed high-resolution mid-infrared (MIR) measurements of active galactic nuclei (AGN). Our goal is to determine the general properties of the circumnuclear dusty environments. Methods: We used the MIR interferometric data of a sample of AGNs provided by the instrument MIDI/VLTI and followed a statistical approach to compare the observed distribution of the interferometric measurements with the distributions computed from clumpy torus models. We mainly tested whether the diversity of Seyfert galaxies can be described using the Standard Model idea, where differences are solely due to a line-of-sight (LOS) effect. In addition to the LOS effects, we performed different realizations of the same model to include possible variations that are caused by the stochastic nature of the dusty models. Results: We find that our entire sample of AGNs, which contains both Seyfert types, cannot be explained merely by an inclination effect and by including random variations of the clouds. Instead, we find that each subset of Seyfert type can be explained by different models, where the filling factor at the inner radius seems to be the largest difference. For the type 1 objects we find that about two thirds of our objects could also be described using a dusty torus similar to the type 2 objects. For the remaining third, it was not possible to find a good description using models with high filling factors, while we found good fits with models with low filling factors. Conclusions: Within our model assumptions, we did not find one single set of model parameters that could simultaneously explain the MIR data of all 21 AGN with LOS effects and random variations alone. We conclude that at least two distinct cloud configurations are required to model the differences in Seyfert galaxies, with volume-filling factors differing by a factor of about 5-10. A continuous transition between the two types cannot be excluded.

  19. BeppoSAX Average Spectra of Seyfert Galaxies

    NASA Astrophysics Data System (ADS)

    Malizia, A.; Bassani, L.; Stephen, J. B.; Di Cocco, G.; Fiore, F.; Dean, A. J.

    2003-05-01

    We have studied the average 3-200 keV spectra of Seyfert galaxies of type 1 and 2, using data obtained with BeppoSAX. The average Seyfert 1 spectrum is well fitted by a power-law continuum with photon spectral index Γ~1.9, a Compton reflection component R~0.6-1 (depending on the inclination angle between the line of sight and the reflecting material), and a high-energy cutoff at around 200 keV; there is also an iron line at 6.4 keV characterized by an equivalent width of 120 eV. Seyfert 2 galaxies, on the other hand, show stronger neutral absorption [NH=(3-4)×1022 atoms cm-2], as expected, but are also characterized by an X-ray power law that is substantially harder (Γ~1.75) and with a cutoff at lower energies (Ec~130 keV); the iron line parameters are instead substantially similar to those measured in type 1 objects. There are only two possible solutions to this problem: to assume more reflection in Seyfert 2 galaxies than observed in Seyfert 1 galaxies or more complex absorption than estimated in the first instance. The first possibility is ruled out by the Seyfert 2 to Seyfert 1 ratio, while the second provides an average Seyfert 2 intrinsic spectrum very similar to that of the Seyfert 1. The extra absorber is likely an artifact due to summing spectra with different amounts of absorption, although we cannot exclude its presence in at least some individual sources. Our result argues strongly for a very similar central engine in both types of galaxies, as expected under the unified theory.

  20. Warm absorbers in X-rays (WAX), a comprehensive high-resolution grating spectral study of a sample of Seyfert Galaxies - II. Warm absorber dynamics and feedback to galaxies

    NASA Astrophysics Data System (ADS)

    Laha, Sibasish; Guainazzi, Matteo; Chakravorty, Susmita; Dewangan, Gulab C.; Kembhavi, Ajit K.

    2016-04-01

    This paper is a sequel to the extensive study of warm absorber (WA) in X-rays carried out using high-resolution grating spectral data from XMM-Newton satellite (WAX-I). Here we discuss the global dynamical properties as well as the energetics of the WA components detected in the WAX sample. The slope of WA density profile (n ∝ r-α) estimated from the linear regression slope of ionization parameter ξ and column density NH in the WAX sample is α = 1.236 ± 0.034. We find that the WA clouds possibly originate as a result of photoionized evaporation from the inner edge of the torus (torus wind). They can also originate in the cooling front of the shock generated by faster accretion disc outflows, the ultrafast outflows, impinging on to the interstellar medium or the torus. The acceleration mechanism for the WA is complex and neither radiatively driven wind nor MHD-driven wind scenario alone can describe the outflow acceleration. However, we find that radiative forces play a significant role in accelerating the WA through the soft X-ray absorption lines, and also with dust opacity. Given the large uncertainties in the distance and volume filling factor estimates of the WA, we conclude that the kinetic luminosity ĖK of WA may sometimes be large enough to yield significant feedback to the host galaxy. We find that the lowest ionization states carry the maximum mass outflow, and the sources with higher Fe M UTA absorption (15-17 Å) have more mass outflow rates.

  1. EXTENDED NARROW-LINE EMISSION IN THE BRIGHT SEYFERT 1.5 GALAXY HE 2211-3903

    SciTech Connect

    Scharwaechter, J.; Dopita, M. A.; Zuther, J.; Fischer, S.; Eckart, A.; Komossa, S.

    2011-08-15

    Extended narrow-line regions (ENLRs) and extended emission-line regions have been the focus of integral field spectroscopy aiming at the inner kiloparsecs of nearby Seyfert galaxies as well as the larger environment of high-redshift QSOs. Based on observations with the Wide Field Spectrograph at the 2.3 m telescope of the Australian National University, we present spatially resolved emission-line diagnostics of the bright Seyfert 1.5 galaxy HE 2211-3903 which is drawn from a sample of the brightest Seyfert galaxies at z < 0.06 with luminosities around the classical Seyfert/QSO demarcation. In addition to the previously known spiral arms of HE 2211-3903, the emission-line maps reveal a large-scale ring with a radius of about 6 kpc which is connected to the active galactic nucleus (AGN) through a bar-like structure. The overall gas kinematics indicates a disk rotation pattern. The emission-line ratios show Seyfert-type, H II region-type, and composite classifications, while there is no strong evidence of LINER-type ratios. Shock ionization is likely to be negligible throughout the galaxy. The composite line ratios are explained via a mixing line between AGN and H II region photoionization. Composite line ratios are predominantly found in between the H II regions in the circum-nuclear region, the bar-like structure to the east of the nucleus, and the eastern half of the ring, suggesting AGN photoionization of the low-density interstellar medium in an ENLR on galaxy scales. The line ratios in the nucleus indicate N enrichment, which is discussed in terms of chemical enrichment by Wolf-Rayet and asymptotic giant branch stars during past and ongoing nuclear starburst activity.

  2. Hydrogen line ratios in Seyfert galaxies and low redshift quasars

    NASA Technical Reports Server (NTRS)

    Kriss, G. R.

    1984-01-01

    New observations of the Lymal alpha radiation/hydrogen alpha radiation ratio in a set of X-ray selected active galactic nuclei and an archival study of International Ultraviolet Explorer (IUE) observations of Lymal alpha low redshift quasars and Seyfert galaxies have been used to form a large sample for studying the influence of soft X-rays on the enhancement of Balmer emission in the broad line region. In common models of broad line clouds, the Balmer lines are formed deep in the interior, largely by collisional excitation. Heating within the clouds is provided by soft X-ray radiation, while Lymal alpha is formed mainly by recombination after photoionization. The ratio Lymal alpha/Halpha is expected to depend weakly on the ratio of ionizing ultraviolet luminosity to X-ray luminosity (L sub UV/l sub x). If the Lymal alpha luminosity is used as a measure of L sub UV' a weak dependence of Lymal/H alpha on the X-ray luminosity is found similar to previous results.

  3. Mid-Infrared Silicate Dust Features in Seyfert 1 Spectra

    NASA Astrophysics Data System (ADS)

    Thompson, Grant D.; Levenson, N. A.; Sirocky, M. M.; Uddin, S.

    2007-12-01

    Silicate dust emission dominates the mid-infrared spectra of galaxies, and the dust produces two spectral features, at 10 and 18 μm. These features' strengths (in emission or absorption) and peak wavelengths reveal the geometry of the dust distribution, and they are sensitive to the dust composition. We examine mid-infrared spectra of 32 Seyfert 1 active galactic nuclei (AGN), observed with the Infrared Spectrograph aboard the Spitzer Space Telescope. In the spectra, we typically find the shorter-wavelength feature in emission, at an average peak wavelength of 10.0 μm, although it is known historically as the "9.7 μm" feature. In addition, peak wavelength increases with feature strength. The 10 and 18 μm feature strengths together are sensitive to the dust geometry surrounding the central heating engine. Numerical calculations of radiative transfer distinguish between clumpy and smooth distributions, and we find that the surroundings of these AGN (the obscuring "tori" of unified AGN schemes) are clumpy. Polycyclic aromatic hydrocarbon (PAH) features are associated with star formation, and we find strong PAH emission (luminosity ≥ 1042 erg/s) in only four sources, three of which show independent evidence for starbursts. We will explore the effects of luminosity on dust geometry and chemistry in a comparison sample of quasars. We acknowledge work supported by the NSF under grant number 0237291.

  4. The nuclear and integrated FIR emission of Seyfert galaxies

    NASA Astrophysics Data System (ADS)

    García-González, J.

    2015-09-01

    We present far-infrared (70-500micron) observations obtained with Herschel/PACS and SPIRE of 33 Seyfert galaxies from the Revised Shapley-Ames (RSA) catalogue. We selected these galaxies because they are nearby (median distance of 33Mpc) and have estimates of the nuclear and integrated star formation rates (SFR) from mid-infrared sub-arcsecond resolution and Spitzer/IRS spectroscopy, respectively. We measure the far-infrared nuclear (1kpc), 2kpc, and integrated spectral energy distributions (SEDs) from the Herschel images and estimate the unresolved nuclear emission at 70micron where Herschel provides the best angular resolution (median 0.9kpc). The goal is to select galaxies in our sample whose 70micron is mostly due to dust heated by the AGN. We will compare the 70micron emission together with existing nuclear 1-10micron SEDs and 8-13micron spectroscopy with clumpy torus model predictions. To estimate the AGN-produced 70micron emission we use a number of criteria. These include: (1) elevated nuclear 70/160 micron colours with respect to the typical colours of star forming galaxies, (2) 70micron excess emission with respect to the fit of the far-infrared SEDs with a grey body, (3) dust temperature higher than typical values of star forming galaxies, and (4) comparison of nuclear SFR obtained from 70 microns and mid-IR indicators.

  5. REVERBERATION MAPPING RESULTS FOR FIVE SEYFERT 1 GALAXIES

    SciTech Connect

    Grier, C. J.; Peterson, B. M.; Pogge, R. W.; Martini, Paul; Zu, Y.; Kochanek, C. S.; Shappee, B.; Stanek, K. Z.; Salvo, C. Araya; Beatty, T. G.; Bird, J. C.; Denney, K. D.; Bentz, M. C.; Sergeev, S. G.; Borman, G. A.; Minezaki, T.; Siverd, R.; Bord, D. J.; Che, X.; and others

    2012-08-10

    We present the results from a detailed analysis of photometric and spectrophotometric data on five Seyfert 1 galaxies observed as a part of a recent reverberation mapping program. The data were collected at several observatories over a 140 day span beginning in 2010 August and ending in 2011 January. We obtained high sampling-rate light curves for Mrk 335, Mrk 1501, 3C 120, Mrk 6, and PG 2130+099, from which we have measured the time lag between variations in the 5100 A continuum and the H{beta} broad emission line. We then used these measurements to calculate the mass of the supermassive black hole at the center of each of these galaxies. Our new measurements substantially improve previous measurements of M{sub BH} and the size of the broad line-emitting region for four sources and add a measurement for one new object. Our new measurements are consistent with photoionization physics regulating the location of the broad line region in active galactic nuclei.

  6. PSPC soft x-ray observations of Seyfert 2 galaxies

    NASA Technical Reports Server (NTRS)

    Turner, T. J.; Urry, C. M.; Mushotzky, R. F.

    1993-01-01

    We present the results from ROSAT PSPC soft x-ray (0.1-2.0 keV) observations of six Seyfert 2 galaxies, chosen from the brightest Seyfert 2s detected with the Einstein Imaging Proportional Counter. All of the targets were detected with the ROSAT PSPC. Spatial analysis shows that the source density within a few arcmin of each Seyfert 2 galaxy is a factor of approximately eight higher than in the rest of the inner field of view of the PSPC images. In NGC1365 it appears that the serendipitous sources may be x-ray binary systems in the host galaxy. The proximity of the serendipitous sources, typically within a few arcmin of the target Seyfert 2, means that previous x-ray observations of the Seyfert 2 galaxies have been significantly contaminated, and that source confusion is important on a spatial scale of approximately 1 arcmin. Some spectra, most notably Mrk3 and NGC1365, indicate the presence of a high equivalent width soft x-ray line blend consistent with unresolved iron L and oxygen K emission.

  7. The submillimeter spectral break in Seyfert galaxies

    NASA Technical Reports Server (NTRS)

    Engargiola, G.; Harper, D. A.; Elvis, Martin; Willner, S. P.

    1988-01-01

    Observations have been made of four Seyfert 1 galaxies at 155 microns and three at 370 microns. Two of the galaxies were detected at 155 microns, but none was detected at 370 microns. The 155 microns data and the strong upper limits at 370 microns show that the infrared continua decrease sharply beyond 100-155 microns. These observations depict a clear spectral difference between radio-loud and radio-quiet active galactic nuclei. The limits on the 100-370 microns spectral slope are consistent either with synchrotron self-absorption of a nonthermal source or with thermal dust emission similar to that arising from the disks of normal galaxies. The 155 microns flux from NGC 4151 is spatially extended through a radius of at least 48 arcsec, arguing for substantial dust emission at wavelengths greater than 80 microns and an even shorter cutoff wavelength for nonthermal emission from the active nucleus. The spectral breaks implied by our data suggest that the nuclear nonthermal sources must be smaller than about 10 light hours.

  8. Evolutionary behaviour of AGN: Investigations on BL Lac objects and Seyfert II galaxies

    NASA Astrophysics Data System (ADS)

    Beckmann, V.

    2000-12-01

    The evolution and nature of AGN is still one of the enigmatic questions in astrophysics. While large and complete Quasar samples are available, special classes of AGN, like BL Lac objects and Seyfert II galaxies, are still rare objects. In this work I present two new AGN samples. The first one is the HRX-BL Lac survey, resulting in a sample of X-ray selected BL Lac objects. This sample results from 223 BL Lac candidates based on a correlation of X-ray sources with radio sources. The identification of this sample is 98% complete. 77 objects have been identified as BL Lac objects and form the HRX-BL Lac complete sample, the largest homogeneous sample of BL Lac objects existing today. For this sample, redshifts are now known for 62 objects (81 %). In total I present 101 BL Lac objects in the enlarged HRX-BL Lac survey, for which redshift information is available for 84 objects. During the HRX-BL Lac survey I found several objects of special interest. 1ES 1517+656 turned out to be the brightest known BL Lac object in the universe. 1ES 0927+500 could be the first BL Lac object with a line detected in the X-ray region. RX J1211+2242 is probably the the counterpart of the up to now unidentified gamma-ray source 3EG J1212+2304. Additionally I present seven candidates for ultra high frequency peaked BL Lac objects. RX J1054+3855 and RX J1153+3517 are rare high redshift X-ray bright QSO or accreting binary systems with huge magnetic fields. For the BL Lac objects I suggest an unified scenario in which giant elliptical galaxies, formed by merging events of spiral galaxies at z > 2, start as powerful, radio dominated BL Lacs. As the jet gets less powerful, the BL Lacs start to get more X-ray dominated, showing less total luminosities (for z < 1). This effect is seen in the different evolutionary behavior detected in high and low frequency cut off BL Lac objects (HBL and LBL, respectively). The model of negative evolution is supported by assumptions about the energetic effects

  9. In vitro analysis of the effect of in-line 1.2 micron filters on two formulations of propofol (2,6-diisopropyl phenol).

    PubMed

    Kennedy, Ross A; Kennedy, Michelle L; Morrissey, Hana; Ball, Patrick A

    2015-01-01

    Recent evidence has shown improved outcomes in pediatric intensive care units with the intensive use of intravenous in-line filtration. This has caused resurgence in interest in filter use but has raised questions in relation to emulsion-based formulations such as propofol. Our objective was to test two propofol products, Diprivan(®) and Fresofol(®), with the Pall Lipipor(®) TNA and Lipipor NLF intravenous in-line filters and to assay the content before and after filtration under typical infusion conditions. The propofol emulsions were delivered from a 50 mL syringe through an extension set and into either a Lipipor TNA (50 mL/h(-1)) or Lipipor NLF (20 mL/h(-1)) filter. Samples were taken at regular intervals and assayed using a high-performance liquid chromatography method before and after filtration. No evidence was found of a significant concentration change during passage of either product through either model of filter. Propofol from two products was found to pass through two different types of Pall 1.2 μm intravenous in-line filters. There was no significant change in concentration before and after filtration under typical conditions of administration. In conclusion, administration of these products through these models of in-line filter would be safe and effective.

  10. The Keck OSIRIS Nearby AGN Survey: Tracing Inflow within the Central 200 pc of Seyfert Galaxies

    NASA Astrophysics Data System (ADS)

    Hicks, Erin K. S.; Müller-Sánchez, Francisco; Malkan, Matthew A.; Yu, Po-Chieh

    2016-08-01

    In an effort to identify the fundamental processes driving feeding and feedback in AGN we turn to local Seyfert galaxies and rely on a multi-wavelength approach. With the integral field unit OSIRIS and adaptive optics we characterize the nuclear stars and gas down to scales of 5-30 parsecs in a sample of 40 Seyfert galaxies with the Keck OSIRIS Nearby AGN (KONA) survey. The complex gas kinematics in these near-IR data are interpreted using an integrative approach through comparison with data available at a range of wavelengths. We present first results from the survey with a focus on work aimed at constraining the mechanism(s) driving inflow of material within the central 200 pc. Particularly useful in the identification of inflow mechanisms (e.g. nuclear spiral, external accretion) is spatial correlation of the molecular gas distribution and kinematics with dust features revealed in HST imaging (optical and near-IR). Also informative is comparison with X-ray emission to identify locations likely influenced by interactions with outflows. The stellar kinematics in the sample galaxies (traced by CO bandheads at 2.3 microns) indicate a stellar population within the central few 100 parsecs in circular rotation, and in the majority of the galaxies the molecular gas (traced by H2 emission at 2.1218 microns) is found to have a rotating component co-spatial with the stellar disk. A significant fraction of the galaxies also exhibit kinematic signatures of inflow superimposed on this disk rotation, with inflow driven by secular and non-secular processes identified. We explore statistical trends of the nuclear stellar and molecular gas properties, including primary fueling mechanism, with Seyfert type, AGN luminosity, and host environment with the goal of disentangling which properties are fundamental to the nature of the AGN.

  11. An Expanded RXTE Survey of Long-Term X-ray Variability in Seyfert 1 Galaxies

    NASA Technical Reports Server (NTRS)

    Markowitz, A.; Edelson, R.

    2004-01-01

    The first seven years of RXTE monitoring of Seyfert 1 active galactic nuclei have been systematically analyzed to yield five homogenous samples of 2-12 keV light curves, probing hard X-ray variability on successively longer durations from approx. 1 day to approx. 3.5 years. 2-10 keV variability on time scales of approx. 1 day, as probed by ASCA, are included. All sources exhibit stronger X-ray variability towards longer time scales, with variability amplitudes saturating at the longest time scales, but the increase is greater for relatively higher luminosity sources. The well-documented anticorrelation between variability amplitude and luminosity is confirmed on all time scales. However, anticorrelations between variability amplitude and black hole mass estimate are evident on only the shortest time scales probed. The data are consistent with the models of power spectral density (PSD) movement described in Markowitz et al. (2003) and McHardy et al. (2004), whereby Seyfert 1 galaxies variability can be described by a single, universal PSD shape whose cutoff frequency scales with black hole mass. The best-fitting scaling relations between variability time scale, black hole mass and X-ray luminosity support an average accretion rate of 2% of the Eddington limit for the sample. Nearly all sources exhibit stronger variability in the relatively soft 2-4 keV band compared to the 7-12 keV band on all time scales. Color-flux diagrams support also Seyfert 1s' softening as they brighten. There are indications that relatively less luminous or less massive sources exhibit a greater degree of spectral variability for a given increase in overall flux.

  12. Infrared Emission of Normal Galaxies from 2.5 to 12 Micron: Infrared Space Observatory Spectra, Near-Infrared Continuum, and Mid-Infrared Emission Features

    NASA Astrophysics Data System (ADS)

    Lu, Nanyao; Helou, George; Werner, Michael W.; Dinerstein, Harriet L.; Dale, Daniel A.; Silbermann, Nancy A.; Malhotra, Sangeeta; Beichman, Charles A.; Jarrett, Thomas H.

    2003-05-01

    We present ISOPHOT spectra of the regions 2.5-4.9 μm and 5.8-11.6 μm for a sample of 45 disk galaxies from the US Infrared Space Observatory Key Project on Normal Galaxies. The galaxies were selected to span the range in global properties of normal, star-forming disk galaxies in the local universe. The spectra can be decomposed into three spectral components: (1) continuum emission from stellar photospheres, which dominates the near-infrared (NIR; 2.5-4.9 μm) spectral region; (2) a weak NIR excess continuum, which has a color temperature of ~103 K, carries a luminosity of a few percent of the total far-infrared (FIR) dust luminosity LFIR and most likely arises from the interstellar medium (ISM); and (3) the well-known broad emission features at 6.2, 7.7, 8.6, and 11.3 μm, which are generally attributed to aromatic carbon particles. These aromatic features in emission (AFEs) dominate the mid-infrared (MIR; 5.8-11.6 μm) part of the spectrum and resemble the so-called type A spectra observed in many nonstellar sources and the diffuse ISM in our own Galaxy. The few notable exceptions include NGC 4418, where a dust continuum replaces the AFEs in MIR, and NGC 1569, where the AFEs are weak and the strongest emission feature is [S IV] 10.51 μm. The relative strengths of the AFEs vary by 15%-25% among the galaxies. However, little correlation is seen between these variations and either IRAS 60 μm/100 μm flux density ratio R(60/100) or the FIR/blue luminosity ratio LFIR/LB, two widely used indicators of the current star formation activity, suggesting that the observed variations are not a consequence of the radiation field differences among the galaxies. We demonstrate that the NIR excess continuum and AFE emission are correlated, suggesting that they are produced by similar mechanisms and similar (or the same) material. On the other hand, as the current star formation activity increases, the overall strengths of the AFEs and the NIR excess continuum drop

  13. Relativistic Fe Kα line study in Seyfert 1 galaxies observed with Suzaku

    NASA Astrophysics Data System (ADS)

    Mantovani, G.; Nandra, K.; Ponti, G.

    2016-06-01

    We present an analysis of a sample of Seyfert 1 galaxies observed with Suzaku. The aim of this work is to examine critically the evidence for a relativistic Fe Kα line in the X-ray spectra of these active galactic nuclei. The sample was compiled from those sources in which a relativistic component was missing in at least one XMM-Newton observation. We analysed the Suzaku spectra of these objects in order to have more constraints on the high-energy emission, including the Compton reflection hump. The results show that the relativistic Fe Kα line is detected (at >95 per cent confidence) in all sources observed with high-signal-to-noise ratio (e.g. where the counts in the 5-7 keV energy band are ≳4 × 104). This is in agreement with the idea that relativistic lines are a ubiquitous feature in the spectra of Seyfert galaxies, but are often difficult to detect without very high-quality data. We also investigate the relation between the Fe Kα line and the reflection continuum at high energies. For most of the sample, the strength of the reflection component is consistent with that of the line. There are exceptions in both senses, however i.e. where the reflection continuum is strong but with weak line emission, and vice versa. These observations present a challenge for standard reflection models.

  14. X-RAY PROPERTIES OF NARROW-LINE SEYFERT 1 GALAXIES WITH VERY SMALL BROADLINE WIDTHS

    SciTech Connect

    Ai, Y. L.; Zhou, H. Y.; Wang, T. G.; Zhang, S. H. E-mail: wmy@nao.cas.cn

    2011-01-20

    Narrow-line Seyfert 1 galaxies (NLS1s) with very small broadline widths (say, FWHM(H{beta}) {approx}<1200 km s{sup -1}) represent the extreme type of Seyfert 1 galaxies that have small black hole masses (M{sub BH}) and/or high Eddington ratios (L/L{sub Edd}). Here, we study the X-ray properties of a homogeneously and optically selected sample of 13 such objects, termed as very narrow line Seyfert 1 galaxies, using archival XMM-Newton data. It is found that the Fe K{alpha} emission line is at most weak in these objects. A soft X-ray excess is ubiquitous, with the thermal temperatures falling within a strict range of 0.1-0.2 keV. Our result highlights the puzzling independence of the thermal temperature by extending the relations to even smaller FWHM(H{beta}), i.e., smaller M{sub BH} ({approx}10{sup 6} M{sub sun}) and/or higher L/L{sub Edd}. The excess emission can be modeled by a range of viable models, though the disk reflection and Comptonization models generally give somewhat better fits over the smeared absorption and the p-free models. At the Eddington ratios around unity and above, the X-ray spectral slopes in the 2-10 keV band are systematically flatter than the predictions of the relationship with L/L{sub Edd} suggested previously. Short timescale (1-2 hr) X-ray variability is common, which, together with the variability amplitude computed for some of the objects, is supportive of the scenario that NLS1s are indeed active galactic nuclei with relatively small M{sub BH}.

  15. X-Ray Fluctuation Power Spectral Densities of Seyfert 1 Galaxies

    NASA Technical Reports Server (NTRS)

    Markowitz, A.; Edelson, R.; Vaughan, S.; Uttley, P.; George, I. M.; Griffiths, R. E.; Kaspi, S.; Lawrence, A.; McHandy, I.; Nandra, K.

    2003-01-01

    By combining complementary monitoring observations spanning long, medium and short time scales, we have constructed power spectral densities (PSDs) of six Seyfert 1 galaxies. These PSDs span approx. greater than 4 orders of magnitude in temporal frequency, sampling variations on time scales ranging from tens of minutes to over a year. In at least four cases, the PSD shows a "break," a significant departure from a power law, typically on time scales of order a few days. This is similar to the behavior of Galactic X-ray binaries (XRBs), lower mass compact systems with breaks on time scales of seconds. NGC 3783 shows tentative evidence for a doubly-broken power law, a feature that until now has only been seen in the (much better-defined) PSDs of low-state XRBs. It is also interesting that (when one previously-observed object is added to make a small sample of seven), an apparently significant correlation is seen between the break time scale T and the putative black hole mass M(sub BH), while none is seen between break time scale and luminosity. The data are consistent with the linear relation T = M(sub BH) /10(exp 6.5) solar mass; extrapolation over 6-7 orders of magnitude is in reasonable agreement with XRBs. All of this strengthens the case for a physical similarity between Seyfert 1s and XRBs.

  16. Simultaneous X-ray and optical observations of true type 2 Seyfert galaxies

    NASA Astrophysics Data System (ADS)

    Bianchi, Stefano; Panessa, Francesca; Barcons, Xavier; Carrera, Francisco J.; La Franca, Fabio; Matt, Giorgio; Onori, Francesca; Wolter, Anna; Corral, Amalia; Monaco, Lorenzo; Ruiz, Ángel; Brightman, Murray

    2012-11-01

    We present the results of a campaign of simultaneous X-ray and optical observations of 'true' type 2 Seyfert galaxies candidates, i.e. active galactic nuclei without a broad-line region (BLR). Out of the initial sample composed of eight sources, one object, IC 1631, was found to be a misclassified starburst galaxy, another, Q2130-431, does show broad optical lines, while other two, IRAS 01428-0404 and NGC 4698, are very likely absorbed by Compton-thick gas along the line of sight. Therefore, these four sources are not unabsorbed Seyfert 2s as previously suggested in the literature. On the other hand, we confirm that NGC 3147, NGC 3660 and Q2131-427 belong to the class of true type 2 Seyfert galaxies, since they do not show any evidence for a broad component of the optical lines nor for obscuration in their X-ray spectra. These three sources have low accretion rates (ṁ=L bol /L Edd ≲0.01), in agreement with theoretical models which predict that the BLR disappears below a critical value of Lbol/LEdd. The last source, Mrk 273x, would represent an exception even of these accretion-dependent versions of the Unification Models, due to its high X-ray luminosity and accretion rate, and no evidence for obscuration. However, its optical classification as a Seyfert 2 is only based on the absence of a broad component of Hβ, due to the lack of optical spectra encompassing the Hα band. Based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and the USA (NASA); with the TNG and Nordic Optical Telescope (NOT) operated on the island of La Palma by the Centro Galileo Galilei and the Nordic Optical Telescope Science Association, respectively, in the Spanish Observatorio del Roque de los Muchachos; at the Centro Astronómico Hispano Alemán (CAHA) at Calar Alto, operated jointly by the Max-Planck-Institut für Astronomie and the Instituto de Astrofísica de Andalucía (CSIC); at the European

  17. INVESTIGATING THE CORE MORPHOLOGY-SEYFERT CLASS RELATIONSHIP WITH HUBBLE SPACE TELESCOPE ARCHIVAL IMAGES OF LOCAL SEYFERT GALAXIES

    SciTech Connect

    Rutkowski, M. J.; Hegel, P. R.; Kim, Hwihyun; Windhorst, R. A.; Tamura, Kazuyuki

    2013-07-01

    The unified model of active galactic nuclei (AGNs) has provided a successful explanation for the observed diversity of AGNs in the local universe. However, recent analysis of multi-wavelength spectral and image data suggests that the unified model is only a partial theory of AGNs, and may need to be augmented to remain consistent with all observations. Recent studies using high spatial resolution ground- and space-based observations of local AGNs show that Seyfert class and the ''core'' (r {approx}< 1 kpc) host-galaxy morphology are correlated. Currently, this relationship has only been established qualitatively, by visual inspection of the core morphologies of low-redshift (z < 0.035) Seyfert host galaxies. We re-establish this empirical relationship in Hubble Space Telescope optical imaging by visual inspection of a catalog of 85 local (D < 63 Mpc) Seyfert galaxies. We also attempt to re-establish the core morphology-Seyfert class relationship using an automated, non-parametric technique that combines both existing classification parameter methods (the adapted CAS and G-M {sub 20}) and a new method which implements the Source Extractor software for feature detection in unsharp-mask images. This new method is designed explicitly to detect dust features in the images. We use our automated approach to classify the morphology of the AGN cores and determine that Sy2 galaxies visually appear, on average, to have more dust features than Sy1. With the exception of this ''dustiness'' however, we do not measure a strong correlation between the dust morphology and the Seyfert class of the host galaxy using quantitative techniques. We discuss the implications of these results in the context of the unified model.

  18. X-ray evidence of an obscured nucleus in the type 2 Seyfert galaxy Mkn3

    NASA Astrophysics Data System (ADS)

    Awaki, H.; Koyama, K.; Kunieda, H.; Tawara, Y.

    1990-08-01

    Seyfert galaxies are classified as type 1 or 2 according to the presence or absence of broad emission lines in the optical spectrum. The high velocities indicated by the broad lines in Seyfert 1 galaxies are taken to be good evidence of a compact, massive object, as are the strong and variable hard X-ray sources that are also generally observed in these objects. In contrast, Seyfert 2 galaxies possess neither of these characteristics, so the theory that they too have an accreting massive blackhole is less compelling. Since the discovery by spectropolarimetry of a 'hidden' Seyfert 1 nucleus in the prototypical Seyfert 2, NGC1068, the long-standing hope that the two classes may be unified has been revived. Here from observations by the Ginga satellite that another Seyfert 2, Mkn3, has the X-ray spectral signature of a hidden type 1 nucleus.

  19. Extended ionizing radiation cone from the nucleus of the Seyfert 2 galaxy NGC 1068

    SciTech Connect

    Pogge, R.W.

    1988-05-01

    Recent observations of the Seyfert 2 galaxy NGC 1068 using CCD images are reported. Emission-line images and a simple ionization map are presented which reveal a cone-shaped region of high-ionization gas emanating from the nucleus into the surrounding regions. The implications of these results for the hidden Seyfert 1 model of NGC 1068 and other Seyfert 2 galaxies are discussed. 14 references.

  20. VizieR Online Data Catalog: Soft X-ray properties of Seyfert galaxies (Pfefferkorn+, 2001)

    NASA Astrophysics Data System (ADS)

    Pfefferkorn, F.; Boller, T.; Rafanelli, P.

    2001-04-01

    We have detected 91 out of 99 Seyfert 1 and 47 out of 98 Seyfert 2 galaxies of the Rafanelli sample in the ROSAT X-ray band in pointed and/or All-Sky Survey observations. Spectral information from the survey data could be obtained for 59 Seyfert 1 galaxies and only for one Seyfert 2 galaxy. The tables quote the name of the Seyfert galaxy in column 1 and the ROSAT name in column 2. Columns 3 and 4 contain the ROSAT position. We mostly give the centroid source position from the pointed observation with the higher exposure times. The columns 5 and 6 list the count rates, columns 7 and 8 the corresponding exposure times, columns 9 and 10 the fluxes and columns 11 and 12 the luminosities of the sources detected in ROSAT pointing and survey observations, respectively. The survey count rates were taken from the RASS II catalogue and the pointing count rates were computed from the light curves of the sources. The labels "(p)" and "(h)" in column 5 indicate that the source data are taken from a PSPC or HRI observation. In the columns 9 and 10 we apply the labels "(f)" and "(c)" to mark the data produced by spectral fit or by count rates. This specification applies also for columns 11 and 12. The Galactic column density is given in column 13 (Dickey & Lockman, 1990ARA&A..28..215D), while the column density obtained from the spectral fit is given in column 14. The other spectral fit parameters, namely the monochromatic flux at 1keV and the photon index are also given in columns 15 and 16, respectively. The value "-2.3" of the photon index was used, if no reliable spectral fit could be obtained. When spectral information was available from the survey as well as from the pointed data, we quote the results from the pointed observations. Columns 17 and 18 show the quality of the X-ray identifications both in the pointing and the survey observations, the identifications labeled either with 1 or 2, 1 and 2 indicating high and lower degree of reliability, respectively. In the last

  1. Reddening indicators for quasars and Seyfert 1 galaxies

    NASA Technical Reports Server (NTRS)

    Grandi, S. A.

    1983-01-01

    It is pointed out that a determination of the reddening caused by intervening dust is a prerequisite to understanding the astrophysics of the broad line emission in quasars and their close cousins Seyfert 1 galaxies. Previous discussions of the reddening question have tended to be incomplete. The present investigation represents an attempt to asses critically the various techniques used to measure the reddening to quasars. It is found that if certain arguments presented are correct, there are no useful reddening indicators for the broad lines of quasars and Seyfert 1 galaxies. It seems safest to assume that reddening due to dust associated with quasars is negligible. However, small amounts of reddening toward quasars are certainly possible, and large amounts of reddening, while unlikely, cannot be ruled out.

  2. Analysis of optical imagery for Seyfert's Sextet and VV 172

    NASA Technical Reports Server (NTRS)

    Sulentic, J. W.; Lorre, J. J.

    1983-01-01

    Seyfert's Sextet and VV 172, 5-m photographs have been subjected to image processing to yield field-galaxy density analysis, redshift-scaled imagery, interaction morphology display and enhancement, color difference imagery,modeling of the VV 172 halo, and image texture analysis of the spiral galaxy components of Seyfert's Sextet. An effort is made to evaluate the evidence for physical association of the discordant redshift components of these groups. An especially noteworthy characteristic of the groups is their extended luminous halos. The halo of VV 172 cannot be explained by the overlapping envelopes of galaxies with normal luminosity profiles, and the high redshift spiral galaxy in the Sextet is found to have an asymmetric internal structure and associated filament which suggest gravitational perturbation by the other members of the group.

  3. Reflection in obscured Seyfert galaxies and the CXB

    NASA Astrophysics Data System (ADS)

    Walter, Roland

    We present a study of the average hard X-ray spectra of Seyfert galaxies obtained accumulating one billion seconds of Swift/BAT data and reaching a sensitivity of 20 micro-Cras in the hard X-rays. As already suggested by INTEGRAL data, this analysis confirms that midly obsured Seyfert 2 galaxies feature much more reflection than unabsorbed sources. The ratio of the average spectra of obscured and unobscured sources, derived with high accuracy, is characteristic of a reflection hump with a broad excess peaking at 40 keV. This large reflection cannot be explained easily by the unified model and points towards the clumpy torus model. It also provides a natural explanation for the peak of the cosmic X-ray background without requiring a large population of Compton thick sources.

  4. The nuclear and integrated far-infrared emission of nearby Seyfert galaxies

    NASA Astrophysics Data System (ADS)

    García-González, J.; Alonso-Herrero, A.; Hernán-Caballero, A.; Pereira-Santaella, M.; Ramos-Almeida, C.; Acosta-Pulido, J. A.; Díaz-Santos, T.; Esquej, P.; González-Martín, O.; Ichikawa, K.; López-Rodríguez, E.; Povic, M.; Roche, P. F.; Sánchez-Portal, M.

    2016-06-01

    We present far-infrared (FIR) 70-500 μm imaging observations obtained with Herschel/Photodetector Array Camera (PACS) and Spectral and Photometric Imaging REceiver (SPIRE) of 33 nearby (median distance of 30 Mpc) Seyfert galaxies from the Revised Shapley-Ames (RSA) catalogue. We obtain the FIR nuclear (r = 1 kpc and r = 2 kpc) and integrated spectral energy distributions (SEDs). We estimate the unresolved nuclear emission at 70 μm and we fit the nuclear and integrated FIR SEDs with a grey body model. We find that the integrated FIR emission of the RSA Seyferts in our sample is dominated by emission from the host galaxy, with dust properties similar to those of normal galaxies (non-AGN). We use four criteria to select galaxies whose nuclear 70 μm emission has a significant AGN contribution: (1) elevated 70/160 μm flux ratios, (2) spatially resolved, high dust temperature gradient, (3) 70 μm excess emission with respect to the fit of the FIR SEDs with a grey body, and (4) excess of nuclear SFR obtained from 70 μm over SFR from mid-infrared indicators. 16 galaxies (48 per cent of the initial sample) satisfy at least one of these conditions, whereas 10 satisfy half or more. After careful examination of these, we select six bona fide candidates (18 per cent of the initial sample) and estimate that ˜40-70 per cent of their nuclear (r = 1-2 kpc) 70 μm emission is contributed by dust heated by the AGN.

  5. Infrared emission in Seyfert 2 galaxies - Reprocessed radiation from a dusty torus?

    NASA Technical Reports Server (NTRS)

    Storchi-Bergmann, Thaisa; Mulchaey, John S.; Wilson, Andrew S.

    1992-01-01

    New and existing data for a sample of nine Seyfert 2 galaxies with known 'ionization cones' are combined in order to test whether collimation results from shadowing of radiation from a small isotropic nuclear source by a thick dusty torus. The number of ionizing photons emitted by the compact nucleus is calculated from the emission-line ratios measured for gas within the cones. On the assumption that this compact nuclear source radiates isotropically, the optical-UV power incident on the torus, which is expected to be reradiated in the IR, is determined. It is found that the observed IRAS luminosities are consistent with the torus model in eight of the nine objects with sufficient data to perform the calculation. It is concluded that the data are generally consistent with collimation and reradiation by a dusty torus.

  6. VizieR Online Data Catalog: FeK lines in Seyfert 1 galaxies (Patrick+, 2012)

    NASA Astrophysics Data System (ADS)

    Patrick, A. R.; Reeves, J. N.; Porquet, D.; Markowitz, A. G.; Braito, V.; Lobban, A. P.

    2013-04-01

    The objects included within this sample are listed in Table 1 and are all the Seyfert 1-1.9 AGN with exposures >50ks and greater than 30000 0.6-10.0keV counts which have been observed with Suzaku with data publicly available in the Suzaku data archive (http://heasarc.gsfc.nasa.gov/) as of 2011 September. We also include data from some type 1 radio-loud (BLRGs - non-blazar) AGN, provided they fit the above exposure and count criteria. High-energy X-ray data from Swift-BAT from the 58-month BAT catalogue are also used in addition to that obtained from the HXD detector on-board Suzaku (but allowing the relative cross-normalization to vary), therefore the total energy range covered is 0.6-100.0keV. (4 data files).

  7. Observations and theory of X-rays and gamma-rays from radio-quiet Seyferts

    NASA Technical Reports Server (NTRS)

    Zdziuarski, A. A.

    1995-01-01

    Recent oriented scintillation spectrometer experiment (OSSE) observations of sift gamma-ray emission from radio-quiet Seyfert galaxies as well as their theoretical implications are reviewed. For some Seyferts, the OSSE data can be combined with X-ray data from Ginga and ROSAT. Seyfert 1s have intrinsic power-law spectra with approximately 0.9 extending without a break to at least approximately 200 keV. There is some evidence for a break at higher energies. On top of this intrinsic spectrum there is a Compton reflection component, which corresponds to cold matter covering a approximately 2 pi solid angle as seen by the power-law source. Compton reflection is responsible for a hardening of the spectrum in the approximately 5-30 keV range and a softening at approximately 30-200 keV. This spectrum is then abasorbed by a partially ionized external medium. The spectra of Seyfert 2s are marginally consistent with those of Seyfert 1s modified by strong absorption. However, there are indications that their intrinsic X-ray spectra are harder than those of Seyfert 1s. This is in fact the case for NGC 4151, a Seyfert 1.5. The Seyfert spectra integrated over redshift with cosmological evolution can explain the cosmic X-ray background spectrum from 1 to 100 keV.

  8. THE RELATIONSHIP BETWEEN BLACK HOLE GROWTH AND STAR FORMATION IN SEYFERT GALAXIES

    SciTech Connect

    Diamond-Stanic, Aleksandar M.; Rieke, George H.

    2012-02-20

    We present estimates of black hole accretion rates (BHARs) and nuclear, extended, and total star formation rates for a complete sample of Seyfert galaxies. Using data from the Spitzer Space Telescope, we measure the active galactic nucleus (AGN) luminosity using the [O IV] {lambda}25.89 {mu}m emission line and the star-forming luminosity using the 11.3 {mu}m aromatic feature and extended 24 {mu}m continuum emission. We find that black hole growth is strongly correlated with nuclear (r < 1 kpc) star formation, but only weakly correlated with extended (r > 1 kpc) star formation in the host galaxy. In particular, the nuclear star formation rate (SFR) traced by the 11.3 {mu}m aromatic feature follows a relationship with the BHAR of the form SFR{proportional_to} M-dot{sub BH}{sup 0.8}, with an observed scatter of 0.5 dex. This SFR-BHAR relationship persists when additional star formation in physically matched r = 1 kpc apertures is included, taking the form SFR{proportional_to} M-dot{sub BH}{sup 0.6}. However, the relationship becomes almost indiscernible when total SFRs are considered. This suggests a physical connection between the gas on sub-kiloparsec and sub-parsec scales in local Seyfert galaxies that is not related to external processes in the host galaxy. It also suggests that the observed scaling between star formation and black hole growth for samples of AGNs will depend on whether the star formation is dominated by a nuclear or an extended component. We estimate the integrated black hole and bulge growth that occurs in these galaxies and find that an AGN duty cycle of 5%-10% would maintain the ratio between black hole and bulge masses seen in the local universe.

  9. The Narrow-Line Region of Narrow-Line Seyfert 1 Galaxies

    NASA Astrophysics Data System (ADS)

    Rodríguez-Ardila, A.; Binette, Luc; Pastoriza, Miriani G.; Donzelli, Carlos J.

    2000-08-01

    This work studies the optical emission-line properties and physical conditions of the narrow-line region (NLR) of seven narrow-line Seyfert 1 galaxies (NLS1's) for which high signal-to-noise ratio spectroscopic observations were available. The resolution is 340 km s-1 (at Hα) over the wavelength interval 3700-9500 Å, enabling us to separate the broad and narrow components of the permitted emission lines. Our results show that the flux carried out by the narrow component of Hβ is, on average, 50% of the total line flux. As a result, the [O III] λ5007/Hβ ratio emitted in the NLR varies from 1 to 5, instead of the universally adopted value of 10. This has strong implications for the required spectral energy distribution that ionizes the NLR gas. Photoionization models that consider a NLR composed of a combination of matter-bounded and ionization-bounded clouds are successful at explaining the low [O III] λ5007/Hβ ratio and the weakness of low-ionization lines of NLS1's. Variation of the relative proportion of these two type of clouds nicely reproduces the dispersion of narrow-line ratios found among the NLS1 sample. Assuming similar physical model parameters of both NLS1's and the normal Seyfert 1 galaxy NGC 5548, we show that the observed differences of emission-line ratios between these two groups of galaxies can be explained, to a first approximation, in terms of the shape of the input ionizing continuum. Narrow emission-line ratios of NLS1's are better reproduced by a steep power-law continuum in the EUV-soft X-ray region, with spectral index α~-2. Flatter spectral indices (α~-1.5) match the observed line ratios of NGC 5548 but are unable to provide a good match to the NLS1 ratios. This result is consistent with ROSAT observations of NLS1's, which show that these objects are characterized by steeper power-law indices than those of Seyfert 1 galaxies with strong broad optical lines. Based on observations made at CASLEO. Complejo Astronómico El Leoncito

  10. A Robust Test of the Unified Model for Seyfert Galaxies with Implications for the Starburst Phenomenon

    NASA Technical Reports Server (NTRS)

    Weaver, Kimberly A.

    1997-01-01

    My research involves detailed analysis of X-ray emission from Active Galactic Nuclei (AGN). For over a decade, the paradigm for AGN has rested soundly on the unified model hypothesis, which posits that the only difference between broad-line objects (e.g., Type 1 Seyfert galaxies) and narrow-line objects (e.g., Type 2 Seyferts) is that in the former case our line of sight evades toroidal obscuration surrounding the nucleus, while in the latter, our line of sight is blocked by the optically thick torus. It is well established that some Seyfert 2s contain Seyfert I nuclei (i.e., a hidden broad line region), but whether or not all Seyfert 2s contain obscured Seyfert 1 nuclei or whether some Seyfert 2s are intrinsically Seyfert 2s is not known. Optical, IR, and UV surveys are not appropriate to examine this hypothesis because such emissions are either anisotropic or subject to the effects of obscuration, and thus depend strongly on viewing angle. Hard X-rays, on the other hand, can penetrate gas with column densities as high as 10( exp 24.5) cm(-2) and thus provide reliable, direct probes of the cores of heavily obscured AGN. Combining NASA archival data from the Advanced Satellite of Cosmology and Astrophysics (ASCA), the Rossi X-ray Timing Explorer (RXTE), and Rosat, I am accumulating X-ray data between 0.1 and 60 keV to produce a catalog of the broad-band X-ray spectral properties of Seyfert galaxies. These data will be used to perform concrete tests of the unified model, and (compared with similar data on Starbursts) to examine a possible evolutionary connection between Seyfert and Starburst galaxies.

  11. Detection of Ni 2 lambda 7378 in six Seyfert galaxies

    SciTech Connect

    Halpern, J.P.; Oke, J.B.

    1985-01-01

    A line due to Ni 2 7378 in the Seyfert galaxies NGC 1068, 2110, 3227, 4151, 5506, and Arp 102 B was detected. The average Ni abundance is about 2 times solar, which is 5 times less than in the filaments of the Crab Nebula. This argues for nucleosynthetic processing in the latter. The Ni 2 line is spatially revolved in NGC 1068, and shows at least a factor of 4 enhancement in the Ni abundance away from the nucleus. The off-nuclear abundance of Ni in NGC 1068 approaches that of the Crab, which strongly suggests that type supernovae enriched the off-nuclear gas clouds.

  12. Masas de agujeros negros en Narrow Line Seyfert 1

    NASA Astrophysics Data System (ADS)

    Schmidt, E.; Ferreiro, D.; Oio, G.; Vega, L.; Donoso, L.

    We describe two of the ways to estimate black hole masses in AGN, and then we estimate the black hole masses of 13 Narrow Line Seyfert 1 galaxies with the two methods: virial masses, using the correlation found by Greene & Ho (2005, ApJ, 630, 122); and the correlation found by Tremaine et al. (2002, ApJ, 574, 740). For this work we analyzed the optical spectroscopy data we obtained from CASLEO (San Juan). We compare the results obtained through both methods. FULL TEXT IN SPANISH

  13. Extreme ultraviolet spectroscopy of the Seyfert 1 galaxy Markarian 478

    SciTech Connect

    Liedahl, D.A.; Paerels, F.; Hur, M.Y.; Kahn, S.M.; Fruscione, A.; Bowyer, S.

    1995-06-26

    The Seyfert 1 galaxy Mrk 478, observed during the EUVE all-sky survey, is the brightest EUV source among its class. The SW spectrum of this object shows evidence of discrete emission, although this interpretation is tentative, since the source spectrum must be extracted against a bright background. If the EUV flux is, in fact, composed partly of line emission, the authors attribute the discrete structure to emission from a collision-driven plasma at temperatures {approx_gt} 10{sup 6} K. In this context, they discuss some of the constraints imposed on the emission-line region by this observation.

  14. The circumnuclear environment of the Seyfert 1 galaxy NGC 3516

    SciTech Connect

    Pogge, R.W.; McDonald Observatory, Austin, TX )

    1989-07-01

    Results of an emission-line imaging and spectrophotometric study of the ionized gas in the circumnuclear regions of the Seyfert 1 galaxy NGC 3516 are reported. The morphology and ionization of the gas are consistent with excitation by the power law continuum from the active nucleus. The optical emission-line gas is well aligned with the extended 6 cm radio-continuum emission. The ionization, structure, and published kinematical data are strongly suggestive of an outflow origin for the circumnuclear gas, although important details are missing to firmly establish outflow as the origin of all of the ionized gas. 31 refs.

  15. The Warm Absorber of the Seyfert Galaxy NGC 5548

    NASA Astrophysics Data System (ADS)

    Andrade, M.; Krongold, Y.; Elvis, M.; Nicastro, F.; Binette, L.; Brickhouse, N.

    2008-04-01

    We present a spectral analysis of the X-ray Chandraof the Seyfert 1 Galaxy NGC 5548. The warm absorber present in this object was modeled with the code PHASE. We detected two different outflow velocity systems in this source. One of the absorbing systems has outflow velocity of -1091+/-63 km s(-1) and the other of -568+/-49 km s(-1) . Each system required two absorption components with different ionization level to fit the observed features. Each velocity system may consist of a multi-phase medium.

  16. THE LINK BETWEEN THE HIDDEN BROAD LINE REGION AND THE ACCRETION RATE IN SEYFERT 2 GALAXIES

    SciTech Connect

    Marinucci, Andrea; Bianchi, Stefano; Matt, Giorgio; Nicastro, Fabrizio; Goulding, Andy D.

    2012-04-01

    In the past few years, more and more pieces of evidence have been presented for a revision of the widely accepted unified model of active galactic nuclei. A model based solely on orientation cannot explain all the observed phenomenology. In the following, we will present evidence that accretion rate is also a key parameter for the presence of hidden broad line regions (HBLRs) in Seyfert 2 galaxies. Our sample consists of 21 sources with polarized hidden broad lines and 18 sources without hidden broad lines. We use stellar velocity dispersions from several studies on the Ca II and Mg b triplets in Seyfert 2 galaxies to estimate the mass of the central black holes via the M{sub BH}-{sigma}{sub *} relation. The ratio between the bolometric luminosity, derived from the intrinsic (i.e., unabsorbed) X-ray luminosity, and the Eddington luminosity is a measure of the rate at which matter accretes onto the central supermassive black hole. A separation between Compton-thin HBLR and non-HBLR sources is clear, both in accretion rate (log L{sub bol}/L{sub Edd} = -1.9) and in luminosity (log L{sub bol} = 43.90). When properly luminosity-corrected Compton-thick sources are included, the separation between HBLR and non-HBLR is less sharp but no HBLR source falls below the Eddington ratio threshold. We speculate that non-HBLR Compton-thick sources with accretion rate higher than the threshold do possess a BLR, but something, probably related to their heavy absorption, is preventing us from observing it even in polarized light. Our results for Compton-thin sources support theoretical expectations. In a model presented by Nicastro, the presence of broad emission lines is intrinsically connected with disk instabilities occurring in proximity of a transition radius, which is a function of the accretion rate, becoming smaller than the innermost stable orbit for very low accretion rates and therefore luminosities.

  17. Ultraviolet and optical spectra of high-ionization Seyfert galaxies with narrow lines

    NASA Technical Reports Server (NTRS)

    Crenshaw, D. Michael; Peterson, Bradley M.; Korista, Kirk T.; Wagner, R. Mark; Aufdenberg, Jason P.

    1991-01-01

    Ultraviolet and optical spectra are presented for three unusual Seyfert galaxies (Mrk 1239, Mrk 42, and Mrk 493) that resemble Seyfert 1 galaxies in that they have strong high-ionization lines and strong nonstellar continua, but resemble Seyfert 2 galaxies in that the widths of their permitted lines are as narrow as the widths of their forbidden lines. The He II lambda 1640 and He II lambda 4686 lines are used to determine an upper limit to the reddening experienced by the emission lines. Published optical data show that these particular high-ionization narrow-line (HINL) Seyferts have low lambda 5007 H beta ratios and strong Fe II emission, which suggest the presence of high-density regions. The low Lalpha/H-beta ratios in these objects indicate that high-density clouds are indeed present, and, like the broad-line region clouds in Seyfert 1 galaxies, these clouds have large optical depths with partially ionized zones. Overall, the line ratios and continuum fluxes of these particular HINL Seyferts are indistinguishable from those of broad-lined Seyfert 1 galaxies.

  18. Reflection in obscured Seyfert galaxies and the CXB

    NASA Astrophysics Data System (ADS)

    Walter, Roland; Esposito, Valentino

    2015-08-01

    We present a study of the average hard X-ray spectra of Seyfert galaxies of different types obtained accumulating one billion seconds of Swift/BAT data and reaching a sensitivity of 20 micro-Crab in the hard X-rays. The resulting spectra are representative of the average emission of these objects (in the local Universe) and can be used as a template for the synthesis of the Cosmic X-ray Background.The ratio of the average spectra obtained for Compton-thin obscured and unobscured sources, derived with high accuracy, is characteristic of a reflection hump and confirms that midly obsured and Compton thin Seyfert 2 galaxies feature much more reflection than unabsorbed sources.This large reflection cannot be explained easily by the unified model and points towards the clumpy torus model. It also provides a natural explanation for the peak, intensity and spectral shape of the Cosmic X-ray Background without requiring a large population of Compton thick sources.

  19. Upholding the unified model for AGN: VLT/FORS2 spectropolarimetry of Seyfert 2 galaxies

    NASA Astrophysics Data System (ADS)

    Ramos Almeida, Cristina; Martínez González, M.; Asensio Ramos, A.; Acosta Pulido, J.; Hönig, S.; Alonso-Herrero, A.; Tadhunter, C.; González-Martín, O.

    2016-08-01

    The origin of the unification model for AGN was the detection of broad hydrogen recombination lines in the optical polarized spectrum of the Seyfert 2 galaxy (Sy2) NGC 1068. Since then, a search for the hidden broad-line region (HBLR) of nearby Sy2s started, but polarized broad lines have only been detected in ~30-40% of the nearby Sy2s observed to date. Here we present new VLT/FORS2 optical spectropolarimetry of a sample of 15 Sy2s, including Compton-thin and Compton-thick sources. The sample includes six galaxies without previously published spectropolarimetry, some of them normally treated as non-hidden BLR (NHBLR) objects in the literature, and four Sy2s classified as NHBLR based on previous data. We report >4sigma detections of a HBLR in 11 of these galaxies (73% of the sample). Our results confirm that at least some NHBLRs were misclassified, bringing previous publications reporting differences between HBLR and NHBLR objects into question. We detect broad Ha and Hb components in polarized light for 9 targets, and just broad Ha for the other two. We do not find any correlation between the properties of the polarized spectra and the column densities measured from the X-rays or torus inclination, but a larger sample is required to confirm this.

  20. The Seyfert-Starburst Connection in X-rays. 1; The Data

    NASA Technical Reports Server (NTRS)

    Levenson, N. A.; Weaver, K. A.; Heckman, T. M.; White, Nicholas E. (Technical Monitor)

    2002-01-01

    We analyze X-ray spectra and images of a sample of Seyfert 2 galaxies that unambiguously contain starbursts, based on their optical and UV characteristics. Although all sample members contain active galactic nuclei (AGNs), supermassive black holes or other related processes at the galactic centers alone cannot account for the total X-ray emission in all instances. Eleven of the 12 observed galaxies are significantly resolved with the ROSAT High Resolution Imager, while six of the eight sources observed with the lower resolution Position Sensitive Proportional Counter also appear extended on larger scales. The X-ray emission is extended on physical scales of 10 kpc and greater, which we attribute to starburst-driven outflows and supernova heating of the interstellar medium. Spectrally, a physically motivated composite model of the X-ray emission that includes a heavily absorbed (N(sub H) greater than 10(exp 23)/sq cm) nuclear component (the AGN), power-law-like scattered AGN flux, and a thermal starburst describes this sample well. Half the sample exhibit iron K(alpha) lines, which are typical of AGNs.

  1. JET PROPERTIES OF GeV-SELECTED RADIO-LOUD NARROW-LINE SEYFERT 1 GALAXIES AND POSSIBLE CONNECTION TO THEIR DISK AND CORONA

    SciTech Connect

    Sun, Xiao-Na; Lin, Da-Bin; Liang, En-Wei; Zhang, Jin; Xue, Zi-Wei; Zhang, Shuang-Nan

    2015-01-01

    The observed spectral energy distributions of five GeV-selected narrow-line Seyfert 1 (NLS1) galaxies are fitted with a model including the radiation ingredients from the relativistic jet, the accretion disk, and the corona. We compare the properties of these GeV NLS1 galaxies with flat spectrum radio quasars (FSRQs), BL Lacertae objects (BL Lacs), and radio-quiet (RQ) Seyfert galaxies, and explore possible hints for jet-disk/corona connection. Our results show that the radiation physics and the jet properties of the GeV NLS1 galaxies resemble that of FSRQs. The luminosity variations of PMN J0948+0022 and 1H 0323+342 at the GeV band is tightly correlated with the beaming factor (δ), similar to that observed in FSRQ 3C 279. The accretion disk luminosities and the jet powers of the GeV NLS1 galaxies cover both the ranges of FSRQs and BL Lacs. With the detection of bright corona emission in 1H 0323+342, we show that the ratio of the corona luminosity (L {sub corona}) to the accretion disk luminosity (L {sub d}) is marginally within the high end of this ratio distribution for an RQ Seyfert galaxy sample, and the variation of jet luminosity may connect with L {sub corona}. However, it is still unclear whether a system with a high L {sub corona}/L {sub d} ratio prefers to power a jet.

  2. MULTIWAVELENGTH MONITORING OF THE ENIGMATIC NARROW-LINE SEYFERT 1 PMN J0948+0022 IN 2009 MARCH-JULY

    SciTech Connect

    Abdo, A. A.; Ackermann, M.; Ajello, M.; Bechtol, K.; Berenji, B.; Bloom, E. D.; Borgland, A. W.; Axelsson, M.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Brez, A.; Ballet, J.; Bastieri, D.; Baughman, B. M.; Bonamente, E.; Brigida, M.; Bruel, P.

    2009-12-10

    Following the recent discovery of gamma rays from the radio-loud narrow-line Seyfert 1 galaxy PMN J0948+0022 (z = 0.5846), we started a multiwavelength campaign from radio to gamma rays, which was carried out between the end of 2009 March and the beginning of July. The source displayed activity at all the observed wavelengths: a general decreasing trend from optical to gamma-ray frequencies was followed by an increase of radio emission after less than two months from the peak of the gamma-ray emission. The largest flux change, about a factor of about 4, occurred in the X-ray band. The smallest was at ultraviolet and near-infrared frequencies, where the rate of the detected photons dropped by a factor 1.6-1.9. At optical wavelengths, where the sampling rate was the highest, it was possible to observe day scale variability, with flux variations up to a factor of about 3. The behavior of PMN J0948+0022 observed in this campaign and the calculated power carried out by its jet in the form of protons, electrons, radiation, and magnetic field are quite similar to that of blazars, specifically of flat-spectrum radio quasars. These results confirm the idea that radio-loud narrow-line Seyfert 1 galaxies host relativistic jets with power similar to that of average blazars.

  3. Multiwavelength Monitoring of the Enigmatic Narrow-Line Seyfert 1 PMN J0948+0022 in 2009 March-July

    NASA Astrophysics Data System (ADS)

    Abdo, A. A.; Ackermann, M.; Ajello, M.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Baughman, B. M.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Burnett, T. H.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Casandjian, J. M.; Cavazzuti, E.; Cecchi, C.; Çelik, Ö.; Celotti, A.; Chekhtman, A.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Collmar, W.; Conrad, J.; Costamante, L.; Cutini, S.; de Angelis, A.; de Palma, F.; Silva, E. Do Couto e.; Drell, P. S.; Dumora, D.; Farnier, C.; Favuzzi, C.; Fegan, S. J.; Focke, W. B.; Fortin, P.; Foschini, L.; Frailis, M.; Fuhrmann, L.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gehrels, N.; Germani, S.; Giglietto, N.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Grove, J. E.; Guillemot, L.; Guiriec, S.; Hanabata, Y.; Hays, E.; Hughes, R. E.; Jackson, M. S.; Jóhannesson, G.; Johnson, A. S.; Johnson, W. N.; Kadler, M.; Kamae, T.; Katagiri, H.; Kataoka, J.; Kawai, N.; Kerr, M.; Knödlseder, J.; Kocian, M. L.; Kuss, M.; Lande, J.; Latronico, L.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Madejski, G. M.; Makeev, A.; Max-Moerbeck, W.; Mazziotta, M. N.; McConville, W.; McEnery, J. E.; McGlynn, S.; Meurer, C.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Nestoras, I.; Nolan, P. L.; Norris, J. P.; Nuss, E.; Ohsugi, T.; Omodei, N.; Orlando, E.; Ormes, J. F.; Paneque, D.; Parent, D.; Pavlidou, V.; Pelassa, V.; Pepe, M.; Pesce-Rollins, M.; Piron, F.; Porter, T. A.; Rainò, S.; Rando, R.; Razzano, M.; Readhead, A.; Reimer, O.; Reposeur, T.; Richards, J. L.; Rodriguez, A. Y.; Roth, M.; Ryde, F.; Sadrozinski, H. F.-W.; Sanchez, D.; Sander, A.; Saz Parkinson, P. M.; Scargle, J. D.; Sgrò, C.; Shaw, M. S.; Smith, P. D.; Spandre, G.; Spinelli, P.; Strickman, M. S.; Suson, D. J.; Tagliaferri, G.; Tajima, H.; Takahashi, H.; Tanaka, T.; Thayer, J. B.; Thayer, J. G.; Thompson, D. J.; Tibaldo, L.; Tibolla, O.; Torres, D. F.; Tosti, G.; Tramacere, A.; Uchiyama, Y.; Usher, T. L.; Vasileiou, V.; Vilchez, N.; Vitale, V.; Waite, A. P.; Wang, P.; Wehrle, A. E.; Winer, B. L.; Wood, K. S.; Ylinen, T.; Zensus, J. A.; Ziegler, M.; Fermi/LAT Collaboration; Angelakis, E.; Bailyn, C.; Bignall, H.; Blanchard, J.; Bonning, E. W.; Buxton, M.; Canterna, R.; Carramiñana, A.; Carrasco, L.; Colomer, F.; Doi, A.; Ghisellini, G.; Hauser, M.; Hong, X.; Isler, J.; Kino, M.; Kovalev, Y. Y.; Kovalev, Yu. A.; Krichbaum, T. P.; Kutyrev, A.; Lahteenmaki, A.; van Langevelde, H. J.; Lister, M. L.; Macomb, D.; Maraschi, L.; Marchili, N.; Nagai, H.; Paragi, Z.; Phillips, C.; Pushkarev, A. B.; Recillas, E.; Roming, P.; Sekido, M.; Stark, M. A.; Szomoru, A.; Tammi, J.; Tavecchio, F.; Tornikoski, M.; Tzioumis, A. K.; Urry, C. M.; Wagner, S.

    2009-12-01

    Following the recent discovery of γ rays from the radio-loud narrow-line Seyfert 1 galaxy PMN J0948+0022 (z = 0.5846), we started a multiwavelength campaign from radio to γ rays, which was carried out between the end of 2009 March and the beginning of July. The source displayed activity at all the observed wavelengths: a general decreasing trend from optical to γ-ray frequencies was followed by an increase of radio emission after less than two months from the peak of the γ-ray emission. The largest flux change, about a factor of about 4, occurred in the X-ray band. The smallest was at ultraviolet and near-infrared frequencies, where the rate of the detected photons dropped by a factor 1.6-1.9. At optical wavelengths, where the sampling rate was the highest, it was possible to observe day scale variability, with flux variations up to a factor of about 3. The behavior of PMN J0948+0022 observed in this campaign and the calculated power carried out by its jet in the form of protons, electrons, radiation, and magnetic field are quite similar to that of blazars, specifically of flat-spectrum radio quasars. These results confirm the idea that radio-loud narrow-line Seyfert 1 galaxies host relativistic jets with power similar to that of average blazars.

  4. Multiwavelength Monitoring of the Enigmatic Narrow-Line Seyfert 1 PMN J0948 0022 in March-July 2009

    SciTech Connect

    Abdo, A.A.; Ackermann, M.; Ajello, M.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Baughman, B.M.; Bechtol, K.; Bellazzini, R. Berenji, B.; Bloom, E.D.; Bonamente, E. Borgland, A.W.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Burnett, T.H.; Caliandro, G.A.; /more authors..

    2012-03-29

    Following the recent discovery of {gamma} rays from the radio-loud narrow-line Seyfert 1 galaxy PMN J0948+0022 (z = 0.5846), we started a multiwavelength campaign from radio to {gamma} rays, which was carried out between the end of 2009 March and the beginning of July. The source displayed activity at all the observed wavelengths: a general decreasing trend from optical to {gamma}-ray frequencies was followed by an increase of radio emission after less than two months from the peak of the {gamma}-ray emission. The largest flux change, about a factor of about 4, occurred in the X-ray band. The smallest was at ultraviolet and near-infrared frequencies, where the rate of the detected photons dropped by a factor 1.6-1.9. At optical wavelengths, where the sampling rate was the highest, it was possible to observe day scale variability, with flux variations up to a factor of about 3. The behavior of PMN J0948+0022 observed in this campaign and the calculated power carried out by its jet in the form of protons, electrons, radiation, and magnetic field are quite similar to that of blazars, specifically of flat-spectrum radio quasars. These results confirm the idea that radio-loud narrow-line Seyfert 1 galaxies host relativistic jets with power similar to that of average blazars.

  5. INDECENT EXPOSURE IN SEYFERT 2 GALAXIES: A CLOSE LOOK

    SciTech Connect

    Tran, Hien D.; Lyke, J. E.; Mader, Jeff A.

    2011-01-10

    NGC 3147, NGC 4698, and 1ES 1927+654 are active galaxies that are classified as Seyfert 2s, based on the line ratios of strong narrow emission lines in their optical spectra. However, they exhibit rapid X-ray spectral variability and/or little indication of obscuration in X-ray spectral fitting, contrary to expectation from the active galactic nucleus (AGN) unification model. Using optical spectropolarimetry with LRIS and near-infrared spectroscopy with NIRSPEC at the W. M. Keck Observatory, we conducted a deep search for hidden polarized broad H{alpha} and direct broad Pa{beta} or Br{gamma} emission lines in these objects. We found no evidence for any broad emission lines from the active nuclei of these galaxies, suggesting that they are unobscured, completely 'naked' AGNs that intrinsically lack broad-line regions.

  6. Observational effects of interaction in the Seyfert galaxy NGC 7469

    NASA Technical Reports Server (NTRS)

    Pronik, I. I.; Metik, L.

    1990-01-01

    Some pecularities of the circummucleus of the Seyfert galaxy NGC 7469 were revealed, plausibly caused by interaction with the satellite IC 5283 and a starlike detail, situated on the edge of the west spiral branch 14 seconds from the nucleus. Shock excited H II regions were noted in the part of NGC 7469 turned toward the satellite IC 5283. The galaxy's central radio structure (lambda approx. 6 cm) stretches in the direction toward the satellite IC 5283 and the starlike detail. The spectum and color index of the starlike detail suggest that it is a cluster of early type stars (M sub V = -19 sup m) and dust clouds (A sub V = 3 sup m), in NGC 7469.

  7. Line asymmetry in the Seyfert Galaxy NGC 3783

    NASA Technical Reports Server (NTRS)

    Ramirez, J. M.; Bautista, Manuel; Kallman, Timothy

    2005-01-01

    We have reanalyzed the 900 ks Chandra X-ray spectrum of NGC 3783, finding evidence on the asymmetry of the spectral absorption lines. The lines are fitted with a parametric expression that results from an analytical treatment of radiatively driven winds. The line asymmetry distribution derived from the spectrum is consistent with a non-spherical outflow with a finite optical depth. Within this scenario, our model explains the observed correlations between the line velocity shifts and the ionization parameter and between the line velocity shift and the line asymmetry. The present results may provide a framework for detailed testing of models for the dynamic and physical properties of warm absorber in Seyfert galaxies.

  8. Reverberation mapping of the Seyfert 1 galaxy NGC 7469

    SciTech Connect

    Peterson, B. M.; Grier, C. J.; Pogge, R. W.; De Rosa, G.; Denney, K. D.; Martini, Paul; Zu, Y.; Kochanek, C. S.; Shappee, B.; Araya Salvo, C.; Beatty, T. G.; Bird, J. C.; Horne, Keith; Bentz, M. C.; Sergeev, S. G.; Borman, G. A.; Minezaki, T.; Siverd, R. J.; Bord, D. J.; and others

    2014-11-10

    A large reverberation-mapping study of the Seyfert 1 galaxy NGC 7469 has yielded emission-line lags for Hβ λ4861 and He II λ4686 and a central black hole mass measurement M {sub BH} ≈ 1 × 10{sup 7} M {sub ☉}, consistent with previous measurements. A very low level of variability during the monitoring campaign precluded meeting our original goal of recovering velocity-delay maps from the data, but with the new Hβ measurement, NGC 7469 is no longer an outlier in the relationship between the size of the Hβ-emitting broad-line region and the luminosity of the active galactic nucleus. It was necessary to detrend the continuum and Hβ and He II λ4686 line light curves and those from archival UV data for different time-series analysis methods to yield consistent results.

  9. The Origin of the Blue Featureless Continuum in Seyfert 2 Nuclei: CYCLE3MEDIUM

    NASA Astrophysics Data System (ADS)

    Filippenko, Alex

    1992-06-01

    Recent spectropolarimetric studies of Seyfert 2 nuclei have shown that NGC 4922B has very low polarization, despite having a rather prominent blue featureless continuum (BFC). Broad permitted lines also appear to be absent, both in direct and reflected light. These observed characteristics conflict with the predictions of simple Seyfert unified models, which assume that the viewing angle is the only parameter that determines whether the object appears as a Seyfert 1 or a Seyfert 2 nucleus. If all Seyfert 2s behave like the prototypical NGC 1068, it is expected that the BFC should be polarized at least a few percent and that broad lines be present in polarized light. A possible explanation for NGC 4922B is that the classical broad-line region does not exist in this object. We should be able to test this by examining the line profiles of Ly-alpha, C IV, and Mg II. If this object does indeed harbor a hidden Seyfert 1 nucleus, we should also be able to detect broad Fe II emission in the UV. Another possibility is that the BFC originates from a population of hot stars. Much evidence has recently been accumulated that hot stars may play a significant role in Seyfert 2 nuclei. If so, then FOS spectra should reveal stellar absorption features (e.g., C IV, Si IV), and FOC images should appear extended. The shape of the UV continuum will also be useful in discriminating between a stellar or an AGN ionizing source. We believe that this study has important implications for the Seyfert unified model.

  10. Observational model of the ionized gas in Seyfert and radio-galaxy nuclei*

    PubMed Central

    Osterbrock, Donald E.

    1978-01-01

    Equivalent widths of the total emission-line Hβ in Seyfert 1, Seyfert 2, and intermediate-type Seyfert galaxies, expressed in terms of the featureless continuum, all have approximately the same frequency distribution. This suggests that the energy-input mechanism to both the narrow-line, low-density gas and the broad-line, high-density gas is photoionization by the featureless continuum. The reason for the weakness of the narrow emission lines in extreme Seyfert 1 galaxies is then the absorption of most of the ionizing photons in the dense gas near the central source. The statistics of line widths can be fitted by a model in which the dense gas has typical rotational velocity 5000 km/sec and typical turbulent velocity 2000 km/sec. A model is proposed in which the dense gas forms a rotating, turbulent disk with dimension ≈0.1 pc and height/diameter ≈2/5. Seyfert 2 galaxies are objects with little dense gas, and intermediate-type Seyfert galaxies are objects in which the dense gas is optically thin to ionizing radiation at least along the poles. Most radio galaxies have strong narrow emission lines, suggesting that escape of radio plasma can only occur where some ionizing photons can also escape from the dense gas. Other predictions, implications, and tests of this model are discussed. Images PMID:16592488

  11. Is there a connection between broad absorption line quasars and narrow-line Seyfert 1 galaxies?

    SciTech Connect

    Grupe, Dirk; Nousek, John A.

    2015-02-01

    We consider whether broad absorption line quasars (BAL QSOs) and narrow-line Seyfert 1 galaxies (NLS1s) are similar, as suggested by Brandt and Gallagher and Boroson. For this purpose, we constructed a sample of 11 BAL QSOs from existing Chandra and Swift observations. We found that BAL QSOs and NLS1s both operate at high Eddington ratios L/L{sub Edd}, although BAL QSOs have slightly lower L/L{sub Edd}. BAL QSOs and NLS1s in general have high Fe ii/Hβ and low [O iii]/Hβ ratios following the classic “Boroson and Green” eigenvector 1 relation. We also found that the mass accretion rates M-dot of BAL QSOs and NLS1s are more similar than previously thought, although some BAL QSOs exhibit extreme mass accretion rates of more than 10 M{sub ⊙} yr{sup −1}. These extreme mass accretion rates may suggest that the black holes in BAL QSOs are relativistically spinning. Black hole masses in BAL QSOs are a factor of 100 larger than NLS1s. From their location on a M−σ plot, we find that BAL QSOs contain fully developed black holes. Applying a principal component analysis to our sample, we find eigenvector 1 to correspond to the Eddington ratio L/L{sub Edd}, and eigenvector 2 to black hole mass.

  12. The nuclear and extended mir-infrared emission of Seyfert galaxies

    NASA Astrophysics Data System (ADS)

    Garcia-Bernete, I.; Ramos Almeida, C.; Acosta-Pulido, J. A.; et al.

    2016-08-01

    We present subarcsecond resolution mid-infrared (MIR) images obtained with 8-10 m-class ground-based telescopes of a complete volume-limited (DL<40 pc) sample of 24 Seyfert galaxies selected from the Swift/BAT nine month Catalog. We use those MIR images to study the nuclear and circumnuclear emission of the galaxies. Using different methods to classify the MIR morphologies on scales of ~200 pc, we found that the majority of the galaxies (75-79%) are extended or possibly extended and 21-25 % are point-like. In general, we find that galaxies with larger inclinations show more extended morphologies than face-on galaxies, and we do not find significant differences between the morphologies of Sy1 and Sy2. This extended emission is weak and compact and it represents ~30% of the total MIR emission of the galaxies in the sample. We obtain nuclear and circumnuclear MIR fluxes to investigate their correlation with different AGN and star formation indicators. We find that the nuclear MIR emission (inner ~70 pc) is strongly correlated with the X-ray emission (the harder the X-rays the better the correlation) and with the [O IV]λ25.89 micron emission line. We find the same results, although with more scatter, for the circumnuclear MIR emission. This indicates that AGN photoionization is the dominant source of excitation of the nuclear and circumnuclear MIR emission.

  13. Investigating the dusty torus of Seyfert galaxies using SOFIA/FORCAST photometry

    NASA Astrophysics Data System (ADS)

    Fuller, L.; Lopez-Rodriguez, E.; Packham, C.; Ramos-Almeida, C.; Alonso-Herrero, A.; Levenson, N. A.; Radomski, J.; Ichikawa, K.; García-Bernete, I.; González-Martín, O.; Díaz-Santos, T.; Martínez-Paredes, M.

    2016-11-01

    We present 31.5 μm imaging photometry of 11 nearby Seyfert galaxies observed from the Stratospheric Observatory For Infrared Astronomy (SOFIA) using the Faint Object infraRed CAmera for the SOFIA Telescope (FORCAST). We tentatively detect extended 31 μm emission for the first time in our sample. In combination with this new data set, subarcsecond resolution 1-18 μm imaging and 7.5-13 μm spectroscopic observations were used to compute the nuclear spectral energy distribution (SED) of each galaxy. We found that the turnover of the torus emission does not occur at wavelengths ≤31.5 μm, which we interpret as a lower-limit for the wavelength of peak emission. We used CLUMPY torus models to fit the nuclear infrared (IR) SED and infer trends in the physical parameters of the AGN torus for the galaxies in the sample. Including the 31.5 μm nuclear flux in the SED (1) reduces the number of clumpy torus models compatible with the data, and (2) modifies the model output for the outer radial extent of the torus for 10 of the 11 objects. Specifically, six (60 per cent) objects show a decrease in radial extent while four (40 per cent) show an increase. We find torus outer radii ranging from <1 to 8.4 pc.

  14. The INTEGRAL high energy cut-off distribution of Seyfert galaxies

    NASA Astrophysics Data System (ADS)

    Malizia, Angela; Ubertini, Pietro; Bird, Antony; Bazzano, Angela; Stephen, John; Molina, Manuela; Bassani, Loredana

    We present the primary continuum parameters, the photon index and the high energy cut-off, of Seyfert galaxies extracted from the INTEGRAL complete sample of AGN. We performed a broad band (0.3-100 keV) spectral analysis by fitting simultaneously the soft and hard X-ray spectra obtained by XMM and INTEGRAL/IBIS-Swift/BAT respectively in order to investigate the general properties of these parameters in particular their distribution and mean values. We present the mean photon index for the t type 1 and type 2 objects of the whole sample as well as their mean high energy cut-off. This is the first time that the cut-off energy is constrained in a such large number of AGN. Using the main parameters of the primary continuum, we are able to obtain the actual physical parameters of the Comptonizing region i.e. the plasma temperature kTe the optical depth tau. Finally, with the high S/N spectra starting to come from NuSTAR it will soon be possible to better constrain the cut-off values in many AGN, allowing the determination of more physical models and so to better understand the continuum emission and geometry of the region surrounding black holes.

  15. Radio jet emission from GeV-emitting narrow-line Seyfert 1 galaxies

    NASA Astrophysics Data System (ADS)

    Angelakis, E.; Fuhrmann, L.; Marchili, N.; Foschini, L.; Myserlis, I.; Karamanavis, V.; Komossa, S.; Blinov, D.; Krichbaum, T. P.; Sievers, A.; Ungerechts, H.; Zensus, J. A.

    2015-03-01

    Context. With the current study we aim at understanding the properties of radio emission and the assumed jet from four radio-loud and γ-ray-loud narrow-line Seyfert 1 galaxies that have been detected by Fermi. These are Seyfert 1 galaxies with emission lines at the low end of the FWHM distribution. Aims: The ultimate goal is twofold: first we investigate whether a relativistic jet is operating at the source producing the radio output, and second, we quantify the jet characteristics to understand possible similarities with and differences from the jets found in typical blazars. Methods: We relied on the most systematic monitoring of radio-loud and γ-ray-detected narrow-line Seyfert 1 galaxies in the cm and mm radio bands conducted with the Effelsberg 100 m and IRAM 30 m telescopes. It covers the longest time-baselines and the most radio frequencies to date. This dataset of multi-wavelength, long-term radio light-curves was analysed from several perspectives. We developed a novel algorithm to extract sensible variability parameters (mainly amplitudes and time scales) that were then used to compute variability brightness temperatures and the corresponding Doppler factors. The jet powers were computed from the light curves to estimate the energy output and compare it with that of typical blazars. The dynamics of radio spectral energy distributions were examined to understand the mechanism causing the variability. Results: The length of the available light curves for three of the four sources in the sample allowed a firm understanding of the general behaviour of the sources. They all display intensive variability that appears to be occurring at a pace rather faster than what is commonly seen in blazars. The flaring events become progressively more prominent as the frequency increases and show intensive spectral evolution that is indicative of shock evolution. The variability brightness temperatures and the associated Doppler factors are moderate, implying a mildly

  16. Broad-band properties of the CfA Seyfert Galaxies. II - Infrared to millimeter properties

    NASA Technical Reports Server (NTRS)

    Edelson, R. A.; Malkan, M. A.; Rieke, G. H.

    1987-01-01

    IR and mm observations of the 48 Seyfert 1 and 2 galaxies (SG1s and SG2s) of the CfA sample (Huchra and Berg, 1987) are reported. Data obtained (1) in the NIR using the 1.55-m reflector at Stewart Observatory and the 3-m IRTF during 1984-1986, (2) in the FIR with IRAS, and (3) at 1.3 mm using the 12-m NRAO telescope at KPNO in June 1984 are presented in extensive tables and graphs and characterized in detail. None of the objects was detected at 1.3 mm, and the IR spectra of the SG2s are found to be significantly steeper (indicating thermal emission) than those of SG1s and QSOs (nonthermal emission). Turnover in the IR emission below 100 microns (in half of the objects detected at three or more IRAS wavelengths) is shown to be consistent with an accretion disk in dust-free SG1s and with unusually warm (35-65 K) dust in SG2s. It is inferred that a 60-100-micron cool excess is masking turnover in the other SGs, so that a general association of SG nuclei with strong star formation can be confirmed.

  17. X-ray evidence for ultra-fast outflows in Seyfert galaxies

    NASA Astrophysics Data System (ADS)

    Tombesi, Francesco; Braito, Valentina; Reeves, James; Cappi, Massimo; Dadina, Mauro

    2012-07-01

    X-ray evidence for massive, highly ionized, ultra-fast outflows (UFOs) has been recently reported in a number of AGNs through the detection of blue-shifted Fe XXV/XXVI absorption lines. We present the results of a comprehensive spectral analysis of a large sample of 42 local Seyferts observed with XMM-Newton. Similar results are also obtained from a Suzaku analysis of 5 radio galaxies. We find that UFOs are common phenomena, being present in >40% of the sources. Their outflow velocity distribution is in the range ˜0.03--0.3c, with mean value of ˜0.14c. The ionization parameter is very high, in the range logξ˜3--6 erg~s^{-1}~cm, and the associated column densities are also large, in the range ˜10^{22}--10^{24} cm^{-2}. Their location is constrained at ˜0.0003--0.03pc (˜10^2--10^4 r_s) from the central black hole, consistent with what is expected for accretion disk winds/outflows. The mass outflow rates are in the interval ˜0.01--1M_{⊙}~yr^{-1}. The associated mechanical power is also high, in the range ˜10^{43}--10^{45} erg/s, which indicates that UFOs are capable to provide a significant contribution to the AGN cosmological feedback.

  18. The story of one Seyfert: from intriguingly ultrasoft to unremarkably average

    NASA Astrophysics Data System (ADS)

    Starling, R. L. C.; Done, C.; Jin, C.

    2015-03-01

    We use 4 broadband SEDs spanning 7 years to study the spectral shape and long term variability of RE J2248-511: an unusual AGN discovered in the extreme-UV by the ROSAT Wide Field Camera. This implies a large ultrasoft X-ray flux, which is typical of narrow-line Seyfert 1s, yet its optical lines are clearly broader than the NLS1 definition allows. Here we show that the continuum SED for the brightest epoch dataset is consistent with the mean SED of a standard quasar, and matches well to that from an XMM-SDSS sample of AGN with M/M ⊙ ~ 108 and L/L Edd ~ 0.2. All the correlated optical and soft X-ray variability can be due entirely to a major absorption event. The only remarkable aspect of this AGN is that there is no measurable intrinsic X-ray absorption column in the brightest epoch dataset. The observed FUV flux is determined by the combination of this and the fact that the source lies within a local absorption hole. RE J2248-511, which once defied classification, demonstrates that characterisation of such objects requires multi-epoch, multi-wavelength campaigns.

  19. ROSAT Position Sensitive Proportional Counter spectra of six Seyfert 1 galaxies

    NASA Technical Reports Server (NTRS)

    Turner, T. J.; George, I. M.; Mushotzky, R. F.

    1993-01-01

    We present the results from ROSAT Position Sensitive Proportional Counter observations of six Seyfert 1 galaxies in the soft (0.1-2.0 keV) X-ray band. The sources (Mrk 335, ESO 198-G24, ESO 141-G55, Mrk 509, NGC 7469, and MCG-2-58-22) were chosen to have low absorbing column densities along the line of sight. As expected, it is found that all the sources possess significantly steeper spectra below about 1 keV than observed at higher X-ray energies. Assuming a simple absorbed power-law spectral model, the mean (photon) spectral index for the sample is Gamma = 2.38 +/- 0.25, compared to the canonical 1.7 typically observed in the 2-10 keV band. Furthermore, we find strong evidence for soft X-ray spectral features in half the sources. In NGC 7469 and ESO 198-G24, we find that the addition of a narrow emission line or an absorption edge to the underlying continuum is a significant improvement to the parameterization of the spectra. Mrk 335 also shows evidence for spectral complexity, but from these data it is not possible to unambiguously distinguish between an absorption edge and a steepening of the spectrum at low energies. We examine these results in the light of the accuracy of the PSPC spectral calibration.

  20. Rapid X-ray variability in the Seyfert galaxy NGC 6814. Ph.D. Thesis - Maryland Univ.

    NASA Technical Reports Server (NTRS)

    Tennant, A. F.; Mushotzky, R. F.; Boldt, E. A.; Swank, J. H.

    1981-01-01

    The HEAO-1 A-2 high time resolution X-ray observations of the X-ray emitting Seyfert I Galaxy NGC 6814 are reported. In sharp distinction with a sample of over 30 active galactic nuclei this object showed strong X-ray variability on timescales less than 3 hours. The mean flux on a timescale of 90 minutes varied by a factor of approximately 2.5 corresponding to Delta L sub x being approximately 1 x 10 to the 43rd power ergs/sec. An autocorrelation analysis shows a characteristic time for variability of 100 (+60 or -25) seconds. There is no indication of spectral variability with an upper limit on a change in the power law spectral index of the absolute value of Delta gamma .37, for a factor two change in intensity. The constraints of such rapid variability on a wide variety of X-ray source mechanisms are considered.

  1. Testing for X-ray Periodicities in Seyfert Galaxies

    NASA Technical Reports Server (NTRS)

    Halpern, Jules P.; Oliversen, Ronald J. (Technical Monitor)

    2002-01-01

    The Deep Survey instrument on the Extreme Ultraviolet Explorer obtained long, continuous light-curves of 10 Seyfert galaxies with durations of 5-33 days each. We present a uniform reduction of these data, which account for a total of 209 days of observation. Several of the light curves are uniquely suited to a search for periodicity or QPOs in the range of hours to days that might be expected from dynamical effects in the inner accretion disks around approximately 10(exp 8) solar mass black holes. Power spectra show features in three of the longest observations that could be transient periods: 0.9 days in RX J0437.4-4711, 2.1 days in Ton S180, and 5.8 days in 1H 0419-577. These period values seem to be unrelated to the length of the observations, which are similar in the three cases, but they do roughly scale as the luminosity of the objects, which would be expected in a dynamical scenario if the black hole masses also scale with luminosity. The significance of these periods will be evaluated in a future publication by using the method of Timmer & Konig (1995), which properly takes into account the red-noise properties of AGN light curves.

  2. Suzaku confirms NGC 3660 is an unabsorbed Seyfert 2

    NASA Astrophysics Data System (ADS)

    Rivers, Elizabeth; Brightman, Murray; Bianchi, Stefano; Matt, Giorgio; Nandra, Kirpal; Ueda, Yoshihiro

    2016-06-01

    An enigmatic group of objects, unabsorbed Seyfert 2s may have intrinsically weak broad line regions, obscuration in the line of sight to the BLR but not to the X-ray corona, or so much obscuration that the X-ray continuum is completely suppressed and the observed spectrum is actually scattered into the line of sight from nearby material. NGC 3660 has been shown to have weak broad optical/near-infrared lines, no obscuration in the soft X-ray band, and no indication of "changing look" behavior. The only previous hard X-ray detection of this source by Beppo-SAX seemed to indicate that the source might harbor a heavily obscured nucleus. However, our analysis of a long-look Suzaku observation of this source shows that this is not the case, and that this source has a typical power-law X-ray continuum with normal reflection and no obscuration. We conclude that NGC 3660 is confirmed to have no unidentified obscuration and that the anomolously high Beppo-SAX measurement must be due to source confusion or similar, being inconsistent with our Suzaku measurements as well as non-detections from Swift-Burst Alert Telescope (BAT) and Rossi X-ray Timing Explorer (RXTE).

  3. Color-Magnitude Relationship of Type I Seyfert Galaxies with Redshifts from 0.1

    NASA Astrophysics Data System (ADS)

    Rutherford, Thomas; Gorjian, V.; Granucci, N.; Paulsen, T.; Blackwell, J.; Boyd, M.; Cox, W.; Fratt, E.; Goetsch, B.; Hatlehol, T.; Hiester, L.; Juoni, H.; McGee, C.; Meyer, B.; Michel, S.; Miner, M.; Nanney, P.; Pankratz, E.; Paulsen, L.; Ramsay, D.; Spahr, A.; Westgate, B.

    2014-01-01

    Data from the Sloan Digital Sky Survey (SDSS) and the Galaxy Evolution Explorer (GALEX) satellite were used to construct color-magnitude diagrams of Type I Seyfert galaxies with redshift values of 0.1sample size (almost 1900 objects) and by increasing the covered wavelengths from 0.15 microns to 0.9 microns. Color was plotted against absolute magnitude in several bandwidths, from the far UV to the near infrared. Significant correlations were found at certain z-values.

  4. Rapid x-ray variability from the Seyfert 1 galaxy NGC 4051

    SciTech Connect

    Marshall, F.E.; Holt, S.S.; Mushotzky, R.F.; Becker, R.H.

    1983-06-15

    Strong variable x-ray emission from the nearby low-luminosity Seyfert 1 galaxy NGC 4051 has been discovered during observations with the imaging proportional counter (IPC) of the Einstein Observatory. During one 2304 s observation, the x-ray flux more than doubled in an approximately linear fashion, and a 70% increase for 150 s was seen during another 968 s observation. We present evidence that the x-ray spectrum of NGC 4051 is unusually soft compared with Seyfert 1 galaxies or OSOs. The emission mechanism is probably not synchrotron or synchrotron self-Compton, but the emission can be plausibly explained by various black hole accretion models.

  5. Detection of the O I 11287 A line in the Seyfert 1 galaxy I ZW 1

    NASA Astrophysics Data System (ADS)

    Rudy, Richard J.; Rossano, George S.; Puetter, R. C.

    1989-07-01

    This paper reports a detection of the infrared 11287 A transition of neutral oxygen in the Seyfert 1 galaxy I Zw 1. The observed strength of the feature is 6.5 x 10 to the -14th erg/sq cm sec. When this value is compared to the flux of O I 8446A measured by Persson and McGregor (1985), the ratio of the photon fluxes is unity, to within the measurement uncertainties. This is a direct confirmation that the broad permitted O I lines observed in Seyfert 1 galaxies and quasars arise through fluorescent excitation by Lyman Beta.

  6. Unification of X-ray Winds in Seyfert Galaxies: From Ultra-fast Outflows to Warm Absorbers

    NASA Astrophysics Data System (ADS)

    Tombesi, Francesco; Cappi, M.; Reeves, J.; Nemmen, R.; Braito, V.; Gaspari, M.; Reynolds, C. S.

    2013-04-01

    The existence of ionized X-ray absorbing layers of gas along the line of sight to the nuclei of Seyfert galaxies is a well established observational fact. This material is systematically outflowing and shows a large range in parameters. However, its actual nature and dynamics are still not clear. In order to gain insights into these important issues we performed a literature search for papers reporting the parameters of the soft X-ray warm absorbers (WAs) in 35 type 1 Seyferts and compared their properties to those of the ultra-fast outflows (UFOs) detected in the same sample. The fraction of sources with WAs is >60%, consistent with previous studies. The fraction of sources with UFOs is >34%, >67% of which also show WAs. The large dynamic range obtained when considering all the absorbers together allows us, for the first time, to investigate general relations among them. In particular, we find significant correlations indicating that the closer the absorber is to the central black hole, the higher the ionization, column, outflow velocity and consequently the mechanical power. The absorbers continuously populate the whole parameter space, with the WAs and the UFOs lying always at the two ends of the distribution. This strongly suggest that these absorbers, often considered of different types, could actually represent parts of a single large-scale stratified outflow observed at different locations from the black hole. The observed parameters and correlations are consistent with both radiation pressure through Compton scattering and MHD processes contributing to the outflow acceleration, the latter playing a major role. Most of the absorbers, especially the UFOs, have a sufficiently high mechanical power to significantly contribute to the AGN feedback.

  7. The nuclear and extended mid-infrared emission of Seyfert galaxies

    NASA Astrophysics Data System (ADS)

    García-Bernete, I.; Ramos Almeida, C.; Acosta-Pulido, J. A.; Alonso-Herrero, A.; González-Martín, O.; Hernán-Caballero, A.; Pereira-Santaella, M.; Levenson, N. A.; Packham, C.; Perlman, E. S.; Ichikawa, K.; Esquej, P.; Díaz-Santos, T.

    2016-08-01

    We present subarcsecond resolution mid-infrared (MIR) images obtained with 8-10 m-class ground-based telescopes of a complete volume-limited (DL <40 Mpc) sample of 24 Seyfert galaxies selected from the Swift/BAT nine month catalog. We use those MIR images to study the nuclear and circumnuclear emission of the galaxies. Using different methods to classify the MIR morphologies on scales of ˜400 pc, we find that the majority of the galaxies (75-83%) are extended or possibly extended and 17-25% are point-like. This extended emission is compact and it has low surface brightness compared with the nuclear emission, and it represents, on average, ˜30% of the total MIR emission of the galaxies in the sample. We find that the galaxies whose circumnuclear MIR emission is dominated by star formation show more extended emission (650±700 pc) than AGN-dominated systems (300±100 pc). In general, the galaxies with point-like MIR morphologies are face-on or moderately inclined (b/a˜0.4-1.0), and we do not find significant differences between the morphologies of Sy1 and Sy2. We used the nuclear and circumnuclear fluxes to investigate their correlation with different AGN and SF activity indicators. We find that the nuclear MIR emission (the inner ˜70 pc) is strongly correlated with the X-ray emission (the harder the X-rays the better the correlation) and with the [O IV] λ25.89 μm emission line, indicating that it is AGN-dominated. We find the same results, although with more scatter, for the circumnuclear emission, which indicates that the AGN dominates the MIR emission in the inner ˜400 pc of the galaxies, with some contribution from star formation.

  8. 1ES 1927+654: a bare Seyfert 2

    NASA Astrophysics Data System (ADS)

    Gallo, L. C.; MacMackin, C.; Vasudevan, R.; Cackett, E. M.; Fabian, A. C.; Panessa, F.

    2013-07-01

    1ES 1927+654 is an active galactic nucleus (AGN) that appears to defy the unification model. It exhibits a type-2 optical spectrum, but possesses little X-ray obscuration. XMM-Newton and Suzaku observations obtained in 2011 are used to study the X-ray properties of 1ES 1927+654. The spectral energy distribution derived from simultaneous optical-to-X-ray data obtained with XMM-Newton shows that the AGN has a typical Eddington ratio (L/LEdd = 0.014 - 0.11). The X-ray spectrum and rapid variability are consistent with originating from a corona surrounding a standard accretion disc. Partial covering models can describe the X-ray data; however, the narrow Fe Kα emission line predicted from standard photoelectric absorption is not detected. Ionized partial covering also favours a high-velocity outflow (v ≈ 0.3c), which requires the kinetic luminosity of the wind to be ≳30 per cent of the bolometric luminosity of the AGN. Such values are not unusual, but for 1ES 1927+654 it requires that the wind is launched very close to the black hole (˜10 rg). Blurred reflection models also work well at describing the spectral and timing properties of 1ES 1927+654 if the AGN is viewed nearly edge-on, implying that an inner accretion disc must be present. The high inclination is intriguing as it suggests 1ES 1927+654 could be orientated like a Seyfert 2, in agreement with its optical classification, but viewed through a tenuous torus.

  9. The X-ray Power Density Spectrum of the Seyfert 2 Galaxy NGC 4945: Analysis and Application of the Method of Light Curve Simulations

    SciTech Connect

    Mueller, Martin; /SLAC

    2010-12-16

    The study of the power density spectrum (PDS) of fluctuations in the X-ray flux from active galactic nuclei (AGN) complements spectral studies in giving us a view into the processes operating in accreting compact objects. An important line of investigation is the comparison of the PDS from AGN with those from galactic black hole binaries; a related area of focus is the scaling relation between time scales for the variability and the black hole mass. The PDS of AGN is traditionally modeled using segments of power laws joined together at so-called break frequencies; associations of the break time scales, i.e., the inverses of the break frequencies, with time scales of physical processes thought to operate in these sources are then sought. I analyze the Method of Light Curve Simulations that is commonly used to characterize the PDS in AGN with a view to making the method as sensitive as possible to the shape of the PDS. I identify several weaknesses in the current implementation of the method and propose alternatives that can substitute for some of the key steps in the method. I focus on the complications introduced by uneven sampling in the light curve, the development of a fit statistic that is better matched to the distributions of power in the PDS, and the statistical evaluation of the fit between the observed data and the model for the PDS. Using archival data on one AGN, NGC 3516, I validate my changes against previously reported results. I also report new results on the PDS in NGC 4945, a Seyfert 2 galaxy with a well-determined black hole mass. This source provides an opportunity to investigate whether the PDS of Seyfert 1 and Seyfert 2 galaxies differ. It is also an attractive object for placement on the black hole mass-break time scale relation. Unfortunately, with the available data on NGC 4945, significant uncertainties on the break frequency in its PDS remain.

  10. A Kinematic Study of the Nuclear Stellar Populations in Seyfert Galaxies

    NASA Astrophysics Data System (ADS)

    García-Rissmann, Aurea; Cid Fernandes, Roberto; Asari, N. V.; Vega, Luis Rodolfo; Schmitt, Henrique; González Delgado, Rosa

    2005-05-01

    Recent studies in the optical and UV have detected circumnuclear starbursts in 40% of nearby Seyfert-2 galaxies; about half of the remaining 60% present a UV excess whose nature is not well known, mainly because of the limitations of the current stellar population analysis techniques in the optical and UV domains. A possible way to circumvent these difficulties is to use a determination of the mass-to-light (M/L) ratio, obtained with a combination of velocity dispersion measurements and photometric information. Dynamical information in AGN (particularly in type 2) is better determined from NIR spectroscopic data, where the stellar absorption features are less affected by the nuclear continuum dilution. In this work, we present preliminary results of a spectroscopic survey of more than 60 Seyfert nuclei (mainly Seyfert 2s), conducted at ESO/La Silla and at KPNO. For many of these objects we have complementary data, such as HST images, optical and (in some cases) UV spectroscopy. The long-slit spectroscopy for the purpose of this project was performed around the NIR Ca II triplet lines at 8498, 8542 and 8662Å. Here we describe the analysis steps taken so far, and present the first results concerning velocity dispersion measurements in nuclear regions. With these data we aim to investigate the ambiguous Seyfert 2 nuclei nature, thus contributing to a better understanding of the AGN-starburst connection.

  11. New mechanism of radiation polarization in type 1 Seyfert active galactic nuclei

    NASA Astrophysics Data System (ADS)

    Silant'ev, N. A.; Gnedin, Yu. N.; Piotrovich, M. Yu.; Natsvlishvili, T. M.; Buliga, S. D.

    2016-10-01

    In most type 1 Seyfert active galactic nuclei (AGNs), the optical linear continuum polarization degree is usually small (less than 1 per cent) and the polarization position angle is nearly parallel to the AGN radio axis. However, there are many type 1 AGNs with unexplained intermediate values for both positional angles and polarization degrees. Our explanation of polarization degree and positional angle of type 1 Seyfert AGNs focuses on the reflection of non-polarized radiation from sub-parsec jets in optically thick accretion discs. The presence of a magnetic field surrounding the scattering media will induce Faraday rotation of the polarization plane, which may explain the intermediate values of positional angles if there is a magnetic field component normal to the accretion disc. The Faraday rotation depolarization effect in the disc diminishes the competition between polarization of the reflected radiation with the parallel component of polarization and the perpendicular polarization from internal radiation of the disc (the Milne problem) in favour of polarization of the reflected radiation. This effect allows us to explain the observed polarization of type 1 Seyfert AGN radiation even though the jet optical luminosity is much lower than the luminosity of the disc. We present the calculation of polarization degrees for a number of type 1 Seyfert AGNs.

  12. Infrared spectroscopy of Seyfert 2 galaxies: A look through the obscuring Torus?

    NASA Technical Reports Server (NTRS)

    Goodrich, Robert W.; Veilleux, Sylvain; Hill, Gary J.

    1994-01-01

    We present both high-resolution (R = 1260) and low-resolution (R = 345 and 425) J-band spectra of a sample of 15 Seyfert 2 galaxies. Our goal is to look for broad Pa beta lines, indicating broad-line regions which are hidden by dust from our view at optical wavelengths. Of the 15 objects studied here, three have broad Pa beta lines: MCG-05.23.16, Mrk 463E, and NGC 2992. Mrk 176 and NGC 5728 may also have weak broad lines. In NGC 5506, previously reported to have broad Pa beta and hydrogen alpha lines, we find that the Pa beta line profile is continuous and has the same shape as the nearby line (Fe II) lambda 1.2567, which should not have a broad component. We interpret these observations as gas from the narrow-line region (NLR) with no broad component. In NGC 5506, however, the NLR profiles become broader with increasing wavelength, indicating that highly reddened wings are becoming more readily visible at the longer wavelengths. We confirm the correlation of (O I) lambda 6300/hydrogen alpha and (Fe II) lambda 1.644/Br gamma (the latter transformed to (Fe II) lambda 1.2567/Pa beta to compare with our data) found by previous authors when comparing active galactic nuclei (AGNs), supernova remnants, starbursts, and H II regions. The correlation confirms that in all of these objects both (O I) lambda 6300 and the (Fe II) lines come from partially ionized regions in which hydrogen is mostly neutral. Comparison of the infrared optical depths with column depths determined from X-ray data show a general tendency for the objects with detected broad Pa beta to have lower X-ray columns.

  13. THE RADIO PROPERTIES OF RADIO-LOUD NARROW-LINE SEYFERT 1 GALAXIES ON PARSEC SCALES

    SciTech Connect

    Gu, Minfeng; Chen, Yongjun; Shen, Zhiqiang; Komossa, S.; Zensus, J. A.; Yuan, Weimin; Wajima, Kiyoaki; Zhou, Hongyan

    2015-11-15

    We present the detection of the compact radio structures of 14 radio-loud narrow-line Seyfert 1 (NLS1) galaxies from Very Long Baseline Array (VLBA) observations at 5 GHz performed in 2013. While 50% of the sources of our sample show a compact core only, the remaining 50% exhibit a core-jet structure. The measured brightness temperatures of the cores range from 10{sup 8.4} to 10{sup 11.4} K with a median value of 10{sup 10.1} K, indicating that the radio emission is from non-thermal jets, and that, likely, most sources are not strongly beamed, thus implying a low jet speed in these radio-loud NLS1 galaxies. In combination with archival data taken at multiple frequencies, we find that seven sources show flat or even inverted radio spectra, while steep spectra are revealed in the remaining seven objects. Although all of these sources are very radio-loud with R > 100, their jet properties are diverse in terms of their milliarcsecond (mas) scale (parsec scale) morphology and their overall radio spectral shape. The evidence for slow jet speeds (i.e., less relativistic jets), in combination with the low kinetic/radio power, may offer an explanation for the compact VLBA radio structure in most sources. The mildly relativistic jets in these high accretion rate systems are consistent with a scenario where jets are accelerated from the hot corona above the disk by the magnetic field and the radiation force of the accretion disk. Alternatively, a low jet bulk velocity can be explained by low spin in the Blandford–Znajek mechanism.

  14. UBVRI simultaneous observations of the nucleus of Seyfert galaxy NGC 5548 in 1993-1999

    NASA Astrophysics Data System (ADS)

    Merkulova, N. I.

    2002-05-01

    An ongoing program on photometric and spectral monitoring of some bright Seyfert galaxies has been carried out at the Crimean Astrophysical Observatory since 1989. Results of photometric observations of NGC 5548 obtained with the 1.25 m telescope are reported in this paper; it focuses on the analysis of intranight variations. During 44 observational nights in 1993-1999 in each spectral band of the Johnson UBVRI system, 672 measurements have been performed simultaneously through the round aperture (diameter 15\\arcsec) using differential photometry techniques. The estimated accuracy of each measurement is about 0.01 mag. The peak amplitude R_max = Fmax /Fmin = 2.99 for the whole light curve was observed in the U band, while the minimum amplitude Fmax /Fmin =1.37 occurred in the I band during the full observation period. UBVRI observations and good sampled data of international monitoring campaigns of NGC 5548, were used to calculate Structure Functions. A comparison is made of the characteristics of the long and short time scale variations of NGC 5548 with those of NGC 4151, NGC 7469 and NGC 1275. In order to examine the intranight variations of the nucleus of NGC 5548, standard deviations (SD) of the nightly averaged flux F, and a measure of intranight variability - SD/F were calculated for each night. Using this parameter, a probability characteristics is introduced, and duty cycles (the fraction of time when the galaxy is variable), characterizing the efficiency of the central energy source, were evaluated. It is concluded that intranight variability is really transient in character and manifests itself with different probabilities for different galaxies.

  15. A radio detection survey of narrow-line Seyfert 1 galaxies using very long baseline interferometry at 22 GHz

    NASA Astrophysics Data System (ADS)

    Doi, Akihiro; Oyama, Tomoaki; Kono, Yusuke; Yamauchi, Aya; Suzuki, Syunsaku; Matsumoto, Naoko; Tazaki, Fumie

    2016-10-01

    We conducted a high-sensitivity radio detection survey for 40 narrow-line Seyfert 1 (NLS1) galaxies using a very long baseline interferometry (VLBI) technique at 22 GHz through phase-referencing long-time integration and using a newly developing recorder with a data rate of 8 Gbps, which is a candidate of the next generation VLBI data recording systems of the Japanese VLBI Network. The baseline sensitivity was typically a few mJy. The observations resulted in a detection rate of 12/40 for our radio-selected NLS1 sample: 11 out of the 12 detected NLS1s showed inverted radio spectra between 1.4 and 22 GHz on the basis of the Very Large Array flux densities and the VLBI detections. These high fractions suggest that a compact radio core with a high brightness temperature is frequently associated with NLS1 nuclei. On the other hand, at least half of the sample indicated apparently steep spectra even with the limited VLBI sensitivity. Both the inverted and the steep spectrum radio sources are included in the NLS1 population.

  16. TESTING THE EVOLUTIONARY SEQUENCE BETWEEN HIDDEN BROAD-LINE REGION (HBLR) AND NON-HBLR SEYFERT 2 GALAXIES WITH THE 4000 A BREAK STRENGTHS

    SciTech Connect

    Yu, Po-Chieh; Hwang, Chorng-Yuan; Huang, Kui-Yun; Ohyama, Youichi E-mail: hwangcy@astro.ncu.edu.tw E-mail: ohyama@asiaa.sinica.edu.tw

    2013-05-01

    We compare the 4000 A break (D{sub n} (4000)) strength in the central kpc of hidden broad-line region (HBLR) and non-HBLR Seyfert 2 galaxies to investigate the origin of these galaxies. Our results show that the D{sub n} (4000) strengths in the nuclear regions of the non-HBLR Seyfert 2 galaxies are larger than those in the HBLR galaxies. We also show that the D{sub n} (4000) strength is not related to the morphology of host galaxies. These results imply that the non-HBLR Seyfert 2 galaxies have an older stellar population in nuclear regions than the HBLR galaxies. This suggests that an evolutionary connection might exist between non-HBLR and HBLR Seyfert 2 galaxies. We propose a potential evolutionary scenario and a modified unification model for Seyfert galaxies. In this scheme, Seyfert 1 and HBLR Seyfert 2 galaxies evolve into unabsorbed and absorbed non-HBLR Seyfert 2 galaxies. We also discuss the implications of our results in the hydrogen column density distribution of the non-HBLR Seyfert 2 galaxies.

  17. Models relating the radio emission and ionised gas in Seyfert nuclei

    NASA Technical Reports Server (NTRS)

    Pedlar, A.; Unger, S. W.; Axon, D. J.; Dyson, J. E.

    1987-01-01

    Possible models are discussed in which the radio emitting components in Seyfert II nuclei can compress and accelerate the ambient nuclear medium to produce the characteristics of the narrow line region. A first order model, which considers only the expansion of the radio components, is briefly described. However, in many Seyfert nuclei it appears that the linear motion of the radio components is also important. This can result in shock heating of the ambient medium, and if the cooling time is long enough, can lead to a displacement between the radio component and the associated emission lines. This effect may be present in NGC 1068 and NGC 5929 and by considering ram pressure balance and the cooling length it is possible to estimate lobe velocities and ambient densities.

  18. A new intermediate Seyfert galaxy - X-ray, optical, and radio properties

    NASA Technical Reports Server (NTRS)

    Ghigo, F. D.; Wyckoff, S.; Wardle, J. F. C.; Cohen, N. L.

    1982-01-01

    It is shown that the X-ray source X0459 + 034 is a Seyfert galaxy of intermediate type, and optical spectroscopy and radio observations were performed to study the nature of the object. The object appears almost stellar and slightly diffuse on Palomar Sky Survey prints. The source is identified as a Type 1.5 Seyfert with broad and narrow line components of redshift 0.016 + or - 0.001, according to H-Beta line profile. In addition, the broad line component H-Beta equivalent width is larger than that of the narrow line component by a factor of three. Finally, it is shown that this is a weak radio source with a steep nonthermal spectrum and an angular extent of approximately 3 in., and the composite radio-to-X-ray spectrum suggests that in different spectral regions, different relativistic electron populations or emission mechanisms are contributing factors.

  19. Spectroscopic Observations of Steep Spectrum Narrow-Line Seyfert 1 Galaxies

    NASA Technical Reports Server (NTRS)

    Leighly, Karen

    1999-01-01

    ROSAT observations of narrow-line Seyfert 1s found consistently steep spectra and rapid variability, but ASCA observations show more diversity, very different to classical Seyfert 1s. However, in 3 NLS1s, ASCA finds common characteristics of these exciting new class of AGN (active galactic nuclei): a very strong high temperature soft excess, weak hard tail, a possible blue shifted ionized oxygen edge, and rapid large amplitude variability characterized by flares and quiescent periods. It is necessary to observe many more such objects in order to understand the physical processes underlying the different phenomenology in ASCA. ASCA observations of two NLS1s discovered by ROSAT's all sky survey were proposed and an observation of one of these objects, RX J0439-45, was awarded. The results of spectral and variability analysis are included in Leighly 1999ab, and preliminary results are found in Leighly 1998ab.

  20. IUE Spectra and photoionization models of the Seyfert 2 glaxies NGC 7674 and I Zw 92

    NASA Technical Reports Server (NTRS)

    Kraemer, Steven B.; Wu, Chi-Chao; Crenshaw, D. Michael; Harrington, J. Patrick

    1994-01-01

    The physical conditions in the narrow-line regions of two Seyfert 2 galaxies, NGC 7674 and I Zw 92, are examined using IUE spectra, published optical spectra and multifrequency observations, and photoionization models. For each Seyfert galaxy, the emission-line fluxes were dereddened using the He II lambda(1640)/lambda(4686) ratio. Photoionization models were calculated using a power-law index determined from the He II lambda(4686)/H-beta ratio; the index is very similar to that obtained from a fit to the observed multifrequency continuum from the infrared to the X-rays. The models were calculated in a way that minimized the number of assumptions, and given the uncertainties in the reddening corrections, the calculated ratios match nearly all of the dereddened ratios successfully. a multicomponent model (three components with different densities and ionization parameters) was required to fit the spectrum of I Zw 92, whereas a single component was sufficient for NGC 7674. The CNO abundances are close to solar, although a reduced abundance of up to one-third solar for one or more of the heavy elements is possible. In contrast to a previous study of Mrk 3, dust inside the narrow-line region (NLR) louds was not required to fit the spectra of these two Seyfert galaxies, although the emission lines experience considerable reddening from external dust. Higher signal-to-noise spectra in the UV are essential for placing further restrictions on the reddening and physical conditions in the narrow-line regions of Seyfert galaxies.

  1. Erratum: BeppoSAX Observations of the Maser Seyfert 2 Galaxy ESO 103-G35

    NASA Astrophysics Data System (ADS)

    Wilkes, Belinda J.; Mathur, Smita; Fiore, Fabrizio; Antonelli, Angelo; Nicastro, Fabrizio

    2001-08-01

    In the paper ``BeppoSAX Observations of the Maser Seyfert 2 Galaxy ESO 103-G35'' by Belinda J. Wilkes, Smita Mathur, Fabrizio Fiore, Angelo Antonelli, and Fabrizio Nicastro (ApJ, 549, 248 [2001]), the size of the line-emitting region derived from the line width should read 0.01 pc and not 50 pc as currently listed in the abstract, § 3.4, and § 4.

  2. Connection between the rapidly varying and smooth components in the light curves of Seyfert galaxies

    SciTech Connect

    Gagen-Torn, V.A.

    1987-11-01

    It is shown that for some Seyfert galaxies whose light curves contain a fast (burst) component and a smooth component (components I and II) the amplitude of the flux variation of component I is proportional to the flux of component II. Since components I and II are also identical in their color characteristics, it is very probable that the variability is due to a single smoothly varying and fluctuating source.

  3. Discovery of Relativistic Outflows in the Seyfert Galaxies Ark 564 and Mrk 590

    NASA Astrophysics Data System (ADS)

    Gupta, Anjali; mathur, Smita

    2015-08-01

    Outflows are ubiquitous in AGNs, manifested by blueshifted absorption lines in the soft X-ray and UV bands and have outflow velocities of 100-1000 km s-1. The discovery of ultra-fast outflows (0.1 c) exhibited by blueshifted absorption lines in the hard X-ray band has added an intriguing aspect to the rich field of AGN outflows. The significance of these absorption line detections is often questioned and with only a few lines observed, accurate parametrization of the photoionized plasma becomes difficult. We recently discovered relativistic outflows in the soft X-ray band in two Seyfert galaxies; these detections are robust and alleviate earlier concerns about statistical significance of the lines in the hard X-ray band. I will discuss the our recent results on the discovery of high velocity outflows in the narrow line Seyfert 1 galaxies Ark 564 and Mrk 590. These absorbers are identified through multiple absorption lines at blueshift of 0.1c-0.17c detected in the Chandra HETG-MEG spectra. These high-velocity outflows have ionization parameter and column density typical of low-velocity outflows, but much higher velocity, probing a distinct region in the velocity versus ionization/column parameter space. The presence of such relativistic outflows in Seyfert galaxies poses a challenge to theoretical models of AGN winds. I will briefly discuss existing models and future prospects.

  4. Extended far-infrared emission and star formation in Seyfert galaxies

    NASA Technical Reports Server (NTRS)

    Marston, A. P.

    1994-01-01

    An investigation into the extended distribution of far-infrared (FIR) emission associated with nearby Seyfert galaxies is made using a set of MEM reconstructions of IRAS Chopped Photometric Channel (CPC) data (Marston 1993). The data is compared to a set of HII/starburst galaxy images similarly processed in order to compare distributions and FIR color properties. It is shown that the central 1 kpc or so of Seyfert galaxies show extended FIR emission. FIR colors suggest that the bulk of this emission is not directly associated with an active nucleus. They further suggest that the origins of the majority of the emission is from heated dust associated with star formation surrounding the nucleus rather than dust heated by the active nucleus. Nearby Seyfert galaxies are shown to have a higher concentration of far-infrared emission from their centers than the HII/starburst galaxies and a number appear to reside in disk galaxies with relatively low ongoing star formation in their disks. An example of this is NGC 7582 which has a smooth disk but an active nucleus/starbust center.

  5. Unification of X-ray Winds in Seyfert Galaxies: From Ultra-fast Outflows to Warm Absorbers

    NASA Technical Reports Server (NTRS)

    Tombesi, F.; Cappi, M.; Reeves, J. N.; Nemmen, R. S.; Braito, V.; Gaspari, M.; Reynolds, C. S.

    2013-01-01

    The existence of ionized X-ray absorbing layers of gas along the line of sight to the nuclei of Seyfert galaxies is a well established observational fact. This material is systematically outflowing and shows a large range in parameters. However, its actual nature and dynamics are still not clear. In order to gain insights into these important issues we performed a literature search for papers reporting the parameters of the soft X-ray warm absorbers (WAs) in 35 type 1 Seyferts and compared their properties to those of the ultra-fast outflows (UFOs) detected in the same sample. The fraction of sources with WAs is >60 per cent, consistent with previous studies. The fraction of sources with UFOs is >34 per cent, >67 per cent of which also show WAs. The large dynamic range obtained when considering all the absorbers together, spanning several orders of magnitude in ionization, column, velocity and distance allows us, for the first time, to investigate general relations among them. In particular, we find significant correlations indicating that the closer the absorber is to the central black hole, the higher the ionization, column, outflow velocity and consequently the mechanical power. In all the cases, the absorbers continuously populate the whole parameter space, with the WAs and the UFOs lying always at the two ends of the distribution. These evidence strongly suggest that these absorbers, often considered of different types, could actually represent parts of a single large-scale stratified outflow observed at different locations from the black hole. The UFOs are likely launched from the inner accretion disc and the WAs at larger distances, such as the outer disc and/or torus. We argue that the observed parameters and correlations are, to date, consistent with both radiation pressure through Compton scattering and magnetohydrodynamic processes contributing to the outflow acceleration, the latter playing a major role. Most of the absorbers, especially the UFOs, show

  6. Unification of X-ray winds in Seyfert galaxies: from ultra-fast outflows to warm absorbers

    NASA Astrophysics Data System (ADS)

    Tombesi, F.; Cappi, M.; Reeves, J. N.; Nemmen, R. S.; Braito, V.; Gaspari, M.; Reynolds, C. S.

    2013-04-01

    The existence of ionized X-ray absorbing layers of gas along the line of sight to the nuclei of Seyfert galaxies is a well established observational fact. This material is systematically outflowing and shows a large range in parameters. However, its actual nature and dynamics are still not clear. In order to gain insights into these important issues we performed a literature search for papers reporting the parameters of the soft X-ray warm absorbers (WAs) in 35 type 1 Seyferts and compared their properties to those of the ultra-fast outflows (UFOs) detected in the same sample. The fraction of sources with WAs is >60 per cent, consistent with previous studies. The fraction of sources with UFOs is >34 per cent, >67 per cent of which also show WAs. The large dynamic range obtained when considering all the absorbers together, spanning several orders of magnitude in ionization, column, velocity and distance allows us, for the first time, to investigate general relations among them. In particular, we find significant correlations indicating that the closer the absorber is to the central black hole, the higher the ionization, column, outflow velocity and consequently the mechanical power. In all the cases, the absorbers continuously populate the whole parameter space, with the WAs and the UFOs lying always at the two ends of the distribution. These evidence strongly suggest that these absorbers, often considered of different types, could actually represent parts of a single large-scale stratified outflow observed at different locations from the black hole. The UFOs are likely launched from the inner accretion disc and the WAs at larger distances, such as the outer disc and/or torus. We argue that the observed parameters and correlations are, to date, consistent with both radiation pressure through Compton scattering and magnetohydrodynamic processes contributing to the outflow acceleration, the latter playing a major role. Most of the absorbers, especially the UFOs, show

  7. The Role of Molecular Gas in Obscuring Seyfert Active Galactic Nuclei

    NASA Astrophysics Data System (ADS)

    Hicks, E. K. S.; Davies, R. I.; Malkan, M. A.; Genzel, R.; Tacconi, L. J.; Müller Sánchez, F.; Sternberg, A.

    2009-05-01

    In a sample of local active galactic nuclei (AGNs) studied at a spatial resolution on the order of 10 pc, we show that the interstellar medium traced by the molecular hydrogen ν = 1-0 S(1) line at 2.1 μm forms a geometrically thick, clumpy disk. The kinematics of the molecular gas reveals general rotation, although an additional significant component of random bulk motion is required by the high local velocity dispersion. The size scale of the typical gas disk is found to have a radius of ~30 pc with a comparable vertical height. Within this radius, the average gas mass is estimated to be ~107 M sun based on a typical gas mass fraction of 10%, which suggests column densities of N H ~ 5 × 1023 cm-2. Extinction of the stellar continuum within this same region suggests lower column densities of N H ~2 × 1022 cm-2, indicating that the gas distribution on these scales is dominated by dense clumps. In half of the observed Seyfert galaxies, this lower column density is still great enough to obscure the AGN at optical/infrared wavelengths. We conclude, based on the spatial distribution, kinematics, and column densities that the molecular gas observed is spatially mixed with the nuclear stellar population and is likely to be associated with the outer extent of any smaller scale nuclear obscuring structure. Furthermore, we find that the velocity dispersion of the molecular gas is correlated with the star formation rate per unit area, suggesting a link between the two phenomena, and that the gas surface density follows known "Schmidt-Kennicutt" relations. The molecular/dusty structure on these scales may be dynamic since it is possible that the velocity dispersion of the gas, and hence the vertical disk height, is maintained by a short, massive inflow of material into the nuclear region and/or by intense, short-lived nuclear star formation. Based on observations at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of

  8. Physical Conditions in the Inner Narrow-Line Region of the Seyfert 2 Galaxy Markarian 573

    NASA Astrophysics Data System (ADS)

    Kraemer, S. B.; Trippe, M. L.; Crenshaw, D. M.; Meléndez, M.; Schmitt, H. R.; Fischer, T. C.

    2009-06-01

    We have examined the physical conditions within a bright emission-line knot in the inner narrow-line region (NLR) of the Seyfert 2 galaxy Mrk 573 using optical spectra and photoionization models. The spectra were obtained with the Hubble Space Telescope/Space Telescope Imaging Spectrograph, through the 0farcs2 × 52farcs0 slit, at a position angle of -71fdg2, with the G430L and G750M gratings. Comparing the spatial emission-line profiles, we found [Fe X] λ 6734 barely resolved, [O III] λ5007 centrally peaked, but broader than [Fe X], and [O II] λ3727 the most extended. Spectra of the central knot were extracted from a region 1farcs1 in extent, corresponding to the full width at zero intensity in the cross-dispersion direction, of the knot. The spectra reveal that [Fe X] is broader in velocity width and blueshifted compared with lines from less ionized species. Our estimate of the bolometric luminosity indicates that the active galactic nucleus (AGN) is radiating at or above its Eddington luminosity, which is consistent with its identification as a hidden Narrow-Line Seyfert 1. We were able to successfully match the observed emission-line ratios with a three-component photoionization model. Two components, one to account for the [O III] emission and another in which the [Fe X] arises, are directly ionized by the AGN, while [O II] forms in a third component, which is ionized by a heavily absorbed continuum. Based on our assumed ionizing continuum and the model parameters, we determined that the two directly ionized components are ~55 pc from the AGN. We have found similar radial distances for the central knots in the Seyfert 2 galaxies Mrk 3 and NGC 1068, but much smaller radial distances for the inner NLR in the Seyfert 1 galaxies NGC 4151 and NGC 5548. Although in general agreement with the unified model, these results suggest that the obscuring material in Seyfert galaxies extends out to at least tens of parsecs from the AGN. Based on observations made with the

  9. The Close AGN Reference Survey (CARS). Mrk 1018 returns to the shadows after 30 years as a Seyfert 1

    NASA Astrophysics Data System (ADS)

    McElroy, R. E.; Husemann, B.; Davis, T. A.; Bennert, V. N.; Busch, G.; Combes, F.; Eckart, A.; Perez-Torres, M.; Powell, M.; Scharwächter, J.; Tremblay, G. R.; Urrutia, T.

    2016-09-01

    We report the discovery that the known "changing look" AGN Mrk 1018 has changed spectral type for a second time. New VLT-MUSE data taken in 2015 as part of the Close AGN Reference Survey (CARS) shows that the AGN has returned to its original Seyfert 1.9 classification. The CARS sample is selected to contain only bright type 1 AGN, but Mrk 1018's broad emission lines and continuum, typical of type 1 AGN, have almost entirely disappeared. We use spectral fitting of the MUSE spectrum and previously available spectra to determine the drop in broad line flux and the Balmer decrement. We find that the broad line flux has decreased by a factor of 4.75 ± 0.5 in Hα since an SDSS spectrum was taken in 2000. The Balmer decrement has not changed significantly implying no enhanced reddening with time, but the remaining broad lines are more asymmetric than those present in the type 1 phase. We posit that the change is due to an intrinsic drop in flux from the accretion disk rather than variable extinction or a tidal disruption event.

  10. The Swift Burst Alert Telescope Detected Seyfert 1 Galaxies: X-Ray Broadband Properties and Warm Absorbers

    NASA Astrophysics Data System (ADS)

    Winter, Lisa M.; Veilleux, Sylvain; McKernan, Barry; Kallman, T. R.

    2012-02-01

    We present results from an analysis of the broadband, 0.3-195 keV, X-ray spectra of 48 Seyfert 1-1.5 sources detected in the very hard X-rays with the Swift Burst Alert Telescope (BAT). This sample is selected in an all-sky survey conducted in the 14-195 keV band. Therefore, our sources are largely unbiased toward both obscuration and host galaxy properties. Our detailed and uniform model fits to Suzaku/BAT and XMM-Newton/BAT spectra include the neutral absorption, direct power-law, reflected emission, soft excess, warm absorption, and narrow Fe I Kα emission properties for the entire sample. We significantly detect O VII and O VIII edges in 52% of our sample. The strength of these detections is strongly correlated with the neutral column density measured in the spectrum. Among the strongest detections, X-ray grating and UV observations, where available, indicate outflowing material. The ionized column densities of sources with O VII and O VIII detections are clustered in a narrow range with N warm ~ 1021 cm-2, while sources without strong detections have column densities of ionized gas an order of magnitude lower. Therefore, we note that sources without strong detections likely have warm ionized outflows present but at low column densities that are not easily probed with current X-ray observations. Sources with strong complex absorption have a strong soft excess, which may or may not be due to difficulties in modeling the complex spectra of these sources. Still, the detection of a flat Γ ~ 1 and a strong soft excess may allow us to infer the presence of strong absorption in low signal-to-noise active galactic nucleus spectra. Additionally, we include a useful correction from the Swift BAT luminosity to bolometric luminosity, based on a comparison of our spectral fitting results with published spectral energy distribution fits from 33 of our sources.

  11. The Swift Burst Alert Telescope Detected Seyfert 1 Galaxies: X-Ray Broadband Properties and Warm Absorbers

    NASA Technical Reports Server (NTRS)

    Winter, Lisa M.; Veilleux, Sylvain; McKernan, Barry; Kallman, T.

    2012-01-01

    We present results from an analysis of the broadband, 0.3-195 keV, X-ray spectra of 48 Seyfert 1-1.5 sources detected in the very hard X-rays with the Swift Burst Alert Telescope (BAT). This sample is selected in an all-sky survey conducted in the 14-195 keV band. Therefore, our sources are largely unbiased toward both obscuration and host galaxy properties. Our detailed and uniform model fits to Suzaku/BAT and XMM-Newton/BAT spectra include the neutral absorption, direct power-law, reflected emission, soft excess, warm absorption, and narrow Fe I K[alpha] emission properties for the entire sample. We significantly detect O VII and O VIII edges in 52% of our sample. The strength of these detections is strongly correlated with the neutral column density measured in the spectrum. Among the strongest detections, X-ray grating and UV observations, where available, indicate outflowing material. The ionized column densities of sources with O VII and O VIII detections are clustered in a narrow range with Nwarm [approx] 1021 cm-2, while sources without strong detections have column densities of ionized gas an order of magnitude lower. Therefore, we note that sources without strong detections likely have warm ionized outflows present but at low column densities that are not easily probed with current X-ray observations. Sources with strong complex absorption have a strong soft excess, which may or may not be due to difficulties in modeling the complex spectra of these sources. Still, the detection of a flat [Gamma] [approx] 1 and a strong soft excess may allow us to infer the presence of strong absorption in low signal-to-noise active galactic nucleus spectra. Additionally, we include a useful correction from the Swift BAT luminosity to bolometric luminosity, based on a comparison of our spectral fitting results with published spectral energy distribution fits from 33 of our sources.

  12. Upholding the unified model for active galactic nuclei: VLT/FORS2 spectropolarimetry of Seyfert 2 galaxies

    NASA Astrophysics Data System (ADS)

    Ramos Almeida, C.; Martínez González, M. J.; Asensio Ramos, A.; Acosta-Pulido, J. A.; Hönig, S. F.; Alonso-Herrero, A.; Tadhunter, C. N.; González-Martín, O.

    2016-09-01

    The origin of the unification model for active galactic nuclei (AGN) was the detection of broad hydrogen recombination lines in the optical polarized spectrum of the Seyfert 2 galaxy (Sy2) NGC 1068. Since then, a search for the hidden broad-line region (HBLR) of nearby Sy2s started, but polarized broad lines have only been detected in ˜30-40 per cent of the nearby Sy2s observed to date. Here we present new VLT/FORS2 optical spectropolarimetry of a sample of 15 Sy2s, including Compton-thin and Compton-thick sources. The sample includes six galaxies without previously published spectropolarimetry, some of them normally treated as non-hidden BLR (NHBLR) objects in the literature, four classified as NHBLR, and five as HBLR based on previous data. We report ≥4σ detections of a HBLR in 11 of these galaxies (73 per cent of the sample) and a tentative detection in NGC 5793, which is Compton-thick according to the analysis of X-ray data performed here. Our results confirm that at least some NHBLRs are misclassified, bringing previous publications reporting differences between HBLR and NHBLR objects into question. We detect broad Hα and Hβ components in polarized light for 10 targets, and just broad Hα for NGC 5793 and NGC 6300, with line widths ranging between 2100 and 9600 km s-1. High bolometric luminosities and low column densities are associated with higher polarization degrees, but not necessarily with the detection of the scattered broad components.

  13. Spectra of High-Ionization Seyfert 1 Galaxies: Implications for the Narrow-Line Region

    NASA Technical Reports Server (NTRS)

    Moore, David; Cohen, Ross D.; Marcy, Geoffrey W.

    1996-01-01

    We present line profiles and profile parameters for the Narrow-Line Regions (NLRs) of six Seyfert 1 galaxies with high-ionization lines: MCG 8-11-11, Mrk 79, Mrk 704, Mrk 841, NGC 4151, and NGC 5548. The sample was chosen primarily with the goal of obtaining high-quality [Fe VII] lambda6087 and, when possible, [Fe X] lambda6374 profiles to determine if these lines are more likely formed in a physically distinct 'coronal line region' or are formed throughout the NLR along with lines of lower critical density (n(sub cr)) and/or Ionization Potential (IP). We discuss correlations of velocity shift and width with n(sub cr) and IP. In some objects, lines of high IP and/or n(sub cr) are systematically broader than those of low IP/n(sub cr). Of particular interest, however, are objects that show no correlations of line width with either IP or n(sub cr). In these objects, lines of high and low IP/n(sub cr), are remarkably similar, which is difficult to reconcile with the classical picture of the NLR, in which lines of high and low IP/n(sub cr) are formed in physically distinct regions. We argue for similar spatial extents for the flux in lines with similar profiles. Here, as well as in a modeling-oriented companion paper, we develop further an idea suggested by Moore & Cohen that objects that do and do not show line width correlations with IP/n(sub cr) can both be explained in terms of a single NLR model with only a small difference in the cloud column density distinguishing the two types of object. Overall, our objects do not show correlations between the Full Width at Half-Maximum (FWHM) and IP and/or n(sub cr). The width must be defined by a parameter that is sensitive to extended profile wings in order for the correlations to result. We present models in which FWHM correlations with IP and/or n(sub cr) result only after simulating the lower spectral resolution used in previous observational studies. The models that simulate the higher spectral resolution of our

  14. ROSAT PSPC and HRI observations of the composite starburst/Seyfert 2 galaxy NGC 1672

    NASA Technical Reports Server (NTRS)

    Brandt, W. N.; Halpern, Jules P.; Iwasawa, K.

    1995-01-01

    The nearby barred spiral galaxy NGC 1672 has been observed with the Position Sensitive Proportional Counter (PSPC) and High Resolution Imager (HRI) instruments on board the ROSAT X-ray satellite. NGC 1672 is thought to have an obscured Seyfert nucleus, and it has strong starburst activity as well. Three bright X-ray sources with luminosities 1-2 x 10(exp 40) erg/s are clearly identified with NGC 1672. The strongest lies at the nucleus, and the other two lie at the ends of NGC 1672's prominent bar, locations that are also bright in H alpha and near-infrared images. The nuclear source is resolved by the HRI on about the scale of the recently identified nuclear ring, and one of the sources at the ends of the bar is also probably resolved. The X-ray spectrum of the nuclear source is quite soft, having a Raymond-Smith plasma temperature of approximately equals 0.7 keV and little evidence for intrinsic absorption. The ROSAT band X-ray flux of the nuclear source appears to be dominated not by X-ray binary emission but rather by diffuse gas emission. The absorption and emission properties of the sources, as well as their spatial extents, lead us to models of superbubbles driven by supernovae. However, the large density and emission measure of the nuclear X-ray source stretch the limits that can be comfortably accommodated by these models. We do not detect direct emission from the putative Seyfert nucleus, although an alternative model for the nuclear source is thermal emission from gas that is photoionized by a hidden Seyfert nucleus. The spectra of the other two X-ray sources are harder than that of the nuclear source, and have similar difficulties with regard to superbubble models.

  15. Discovery of a deep Seyfert-2 galaxy at z = 0.222 behind NGC 300

    NASA Astrophysics Data System (ADS)

    Combi, J. A.; García, F.; Rodríguez, M. J.; Gamen, R.; Cellone, S. A.

    2016-08-01

    We report on the unveiling of the nature of the unidentified X-ray source 3XMM J005450.3-373849 as a Seyfert-2 galaxy located behind the spiral galaxy NGC 300 using Hubble Space Telescope data, new spectroscopic Gemini observations and available XMM-Newton and Chandra data. We show that the X-ray source is positionally coincident with an extended optical source, composed of a marginally resolved nucleus/bulge, surrounded by an elliptical disc-like feature and two symmetrical outer rings. The optical spectrum is typical of a Seyfert-2 galaxy redshifted to z = 0.222 ± 0.001, which confirms that the source is not physically related to NGC 300. At this redshift the source would be located at 909 ± 4 Mpc (comoving distance in the standard model). The X-ray spectra of the source are well fitted by an absorbed power-law model. By tying NH between the six available spectra, we found a variable index Γ running from ˜2 in 2000-2001 to 1.4-1.6 in the 2005-2014 period. Alternatively, by tying Γ, we found variable absorption columns of NH ˜ 0.34 × 10-22 cm-2 in 2000-2001, and 0.54-0.75 × 10-22 cm-2 in the 2005-2014 period. Although we cannot distinguish between a spectral or absorption origin, from the derived unabsorbed X-ray fluxes, we are able to assure the presence of long-term X-ray variability. Furthermore, the unabsorbed X-ray luminosities of 0.8-2 × 1043 erg s-1 derived in the X-ray band are in agreement with a weakly obscured Seyfert-2 AGN at z ≈ 0.22.

  16. Constraints on the broad-line region properties and extinction in local Seyferts

    NASA Astrophysics Data System (ADS)

    Schnorr-Müller, Allan; Davies, R. I.; Korista, K. T.; Burtscher, L.; Rosario, D.; Storchi-Bergmann, T.; Contursi, A.; Genzel, R.; Graciá-Carpio, J.; Hicks, E. K. S.; Janssen, A.; Koss, M.; Lin, M.-Y.; Lutz, D.; Maciejewski, W.; Müller-Sánchez, F.; Orban de Xivry, G.; Riffel, R.; Riffel, Rogemar A.; Schartmann, M.; Sternberg, A.; Sturm, E.; Tacconi, L.; Veilleux, S.; Ulrich, O. A.

    2016-11-01

    We use high-spectral resolution (R > 8000) data covering 3800-13 000 Å to study the physical conditions of the broad-line region (BLR) of nine nearby Seyfert 1 galaxies. Up to six broad H I lines are present in each spectrum. A comparison - for the first time using simultaneous optical to near-infrared observations - to photoionization calculations with our devised simple scheme yields the extinction to the BLR at the same time as determining the density and photon flux, and hence distance from the nucleus, of the emitting gas. This points to a typical density for the H I emitting gas of 1011 cm-3 and shows that a significant amount of this gas lies at regions near the dust sublimation radius, consistent with theoretical predictions. We also confirm that in many objects, the line ratios are far from case B, the best-fitting intrinsic broad-line Hα/H β ratios being in the range 2.5-6.6 as derived with our photoionization modelling scheme. The extinction to the BLR, based on independent estimates from H I and He II lines, is AV ≤ 3 for Seyfert 1-1.5s, while Seyfert 1.8-1.9s have AV in the range 4-8. A comparison of the extinction towards the BLR and narrow-line region (NLR) indicates that the structure obscuring the BLR exists on scales smaller than the NLR. This could be the dusty torus, but dusty nuclear spirals or filaments could also be responsible. The ratios between the X-ray absorbing column NH and the extinction to the BLR are consistent with the Galactic gas-to-dust ratio if NH variations are considered.

  17. An X-Ray Reprocessing Model of Disk Thermal Emission in Type 1 Seyfert Galaxies

    NASA Technical Reports Server (NTRS)

    Chiang, James; White, Nicholas E. (Technical Monitor)

    2002-01-01

    Using a geometry consisting of a hot central Comptonizing plasma surrounded by a thin accretion disk, we model the optical through hard X-ray spectral energy distributions of the type 1 Seyfert. galaxies NGC 3516 and NGC 7469. As in the model proposed by Poutanen, Krolik, and Ryde for the X-ray binary Cygnus X-1 and later applied to Seyfert galaxies by Zdziarski, Lubifiski, and Smith, feedback between the radiation reprocessed by the disk and the thermal Comptonization emission from the hot central plasma plays a pivotal role in determining the X-ray spectrum, and as we show, the optical and ultraviolet spectra as well. Seemingly uncorrelated optical/UV and X-ray light curves, similar to those which have been observed from these objects can, in principle, be explained by variations in the size, shape, and temperature of the Comptonizing plasma. Furthermore, by positing a disk mass accretion rate which satisfies a condition for global energy balance between the thermal Comptonization luminosity and the power available from accretion, one can predict the spectral properties of the heretofore poorly measured hard X-ray continuum above approximately 50 keV in type 1 Seyfert galaxies. Conversely, forthcoming measurements of the hard X-ray continuum by more sensitive hard X-ray and soft gamma-ray telescopes, such as those aboard the International Gamma-Ray Astrophysics Laboratory (INTEGRAL) in conjunction with simultaneous optical, UV, and soft X-ray monitoring, will allow the mass accretion rates to be directly constrained for these sources in the context of this model.

  18. Evidence of coronal flaring in narrow-line Seyfert 1 galaxies

    NASA Astrophysics Data System (ADS)

    Gallo, L. C.

    High-energy (E>2 keV) continuum flaring is detected in two narrow-line Seyfert 1 galaxies (I Zw 1 and NAB 0205+024), consistent with occurring in a hot corona distinct from the accretion disc. The flare in I Zw 1 is accompanied by an increase in the amount of gravitationally redshifted reflected emission coming from the accretion disc. This indicates that the high-energy continuum component is compact and located close to the black hole, and could possibly be the base of an aborted jet.

  19. The nature of the optical variations of Seyfert galaxy 3C 120

    SciTech Connect

    Webb, J.R. Austin State Univ., TX )

    1990-01-01

    Results are presented from 61 years of optical observations of the Seyfert galaxy 3C 120. A previously published model of the 3C 120 light curve, derived from power spectrum analysis, is found to be valid for historical as well as current data. It is concluded that the optical variations of 3C 120 can be separated into a linear component, a sinusoidal component, and rapid, high-amplitude flares. Possible sources of the regular variations observed in 3C 120 are also suggested in the context of accretion models and other theoretical models. 15 refs.

  20. Hubble Observations of Kepler-Monitored Seyfert Is

    NASA Astrophysics Data System (ADS)

    Mushotzky, Richard

    2013-10-01

    The bulk of AGN optical variability is generated by viscous processes in the accretion disk. The nature and amplitude of the variability is thought to be strongly connected to the black hole mass and Eddington ratio {McLeod et al 2010}. For the past 3 years we have obtained high-precision {milli-magnitude errors}, densely-sampled {every 30 min}, long-duration {years} optical light curves from Kepler of 28 AGN our team has discovered in the Kepler field. These data permit, for the first time, the precise measurement of the optical variability of a sample of AGN over a wide range of timescales {from hours to years}, BH masses and Eddington ratios, allowing a detailed characterization of the variability processes.To properly model the disk emission and probe the origin of the variability, it is necessary to measure and subtract off the substantial but uncertain contribution due to starlight in the underlying galaxy. Because of the poor angular resolution of Kepler and ground based data, only HST can obtain this data. Without this measurement it is impossible to determine the absolute variability amplitude of the AGN, an accurate black hole mass or AGN luminosity. We request 8 GO orbits for WFC3 imaging of 8 AGN selected to span a wide range of Eddington ratio and black hole mass. These 8 objects are representative of the full range of mass and Eddington ratio of the present Kepler monitored sample. HST observations are crucial to obtain the full value of the already-extraordinary Kepler AGN light curves. In addition the HST observations will determine the nature of the host galaxy, a key parameter in understanding the origin and evolution of AGN.

  1. Mapping Seyfert and LINER Excitation Modes in the Inner kpc of NGC 3393

    NASA Astrophysics Data System (ADS)

    Maksym, W. Peter; Fabbiano, Giuseppina; Elvis, Martin; Karovska, Margarita; Paggi, Alessandro; Raymond, John; Wang, Junfeng; Storchi-Bergmann, Thaisa

    2016-09-01

    We mapped the extended narrowline region (ENLR) of NGC 3393 on scales of r≲ 4\\prime\\prime (˜ 1 kpc) from the nucleus using emission line images of Hα λ6563, [O iii]λ 5007, and [S ii]λ λ 6717,6731, taken with the Hubble Space Telescope as part of the CHandra survey of Extended Emission line Regions in nearby Seyfert galaxies (CHEERS). By mapping these lines onto a spatially resolved Baldwin-Phillips-Terlevich diagram, we investigate the impact of feedback from a Compton-thick active galactic nucleus on its circumnuclear ISM. We find that the expected Seyfert-like emission within the ionization bicone (≲ 3\\prime\\prime ; 770 pc). We also find a new, figure-8-shaped low ionization emission line region (LINER) cocoon enveloping the bicone and defining a sharp (≲ 100 pc) transition between higher and lower-ionization zones. These data illustrate the morphological dependence of ionization states of the ENLR relative to bicone and host gas geometries.

  2. Is HE 0436-4717 Anemic? A deep look at a bare Seyfert 1 galaxy

    NASA Astrophysics Data System (ADS)

    Bonson, K.; Gallo, L. C.; Vasudevan, R.

    2015-06-01

    A multi-epoch, multi-instrument analysis of the Seyfert 1 galaxy HE 0436-4717 is conducted using optical to X-ray data from XMM-Newton and Swift (including the Burst Alert Telescope). Fitting of the UV-to-X-ray spectral energy distribution shows little evidence of extinction and the X-ray spectral analysis does not confirm previous reports of deep absorption edges from O VIII. HE 0436-4717 is a `bare' Seyfert with negligible line-of-sight absorption making it ideal to study the central X-ray emitting region. Three scenarios were considered to describe the X-ray data: partial covering absorption, blurred reflection, and soft Comptonization. All three interpretations describe the 0.5-10.0 keV spectra well. Extrapolating the models to 100 keV results in poorer fits for the partial covering model. When also considering the rapid variability during one of the XMM-Newton observations, the blurred reflection model appears to describe all the observations in the most self-consistent manner. If adopted, the blurred reflection model requires a very low iron abundance in HE 0436-4717. We consider the possibilities that this is an artefact of the fitting process, but it appears possible that it is intrinsic to the object.

  3. 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.

  4. (Astrophysics of binary stars, Seyfert galaxies, quasars, and globular clusters. Final technical report

    SciTech Connect

    Press, W.H.

    1985-03-29

    Several problems were investigated. The time-steady accretion of gas irradiated by a self-consistently generated quasar-like continuum was studied. The observed x-ray sources near the core of the Orion molecular cloud were established to be sufficient to supply all the ionization that is needed to drive the molecular chemistry throughout that portion of the cloud in which the greatest density and diversity of molecular species is found. A new suggestion was put forth for a single pass, high gain, O/sup 5 +/ ion laboratory laser at 1035 A. The only evidence for binaries in globular clusters was found to come from binaries in extreme states, cataclysmic variables, and x-ray sources. The various evolutionary paths possible for highly compact binaries in globular clusters where they come under the simultaneous influence of gravitational radiation and gravitational encounters with field stars were analyzed. The secular evolution of a highly compact binary stellar system, composed of a collapsed object and a low-mass secondary star, in the core of a globular cluster was calculated. The dynamics of the narrow line regions of Seyfert galaxies were investigated. New calculations of the soft x-ray opacity of gas having cosmic elemental abunances were developed for a variety of ionization states. Results were presented of the analysis of 28 Einstein SSS observations of 15 high x-ray luminosity quasars and Seyfert type I nuclei. (GHT)

  5. A global look at X-ray time lags in Seyfert galaxies

    NASA Astrophysics Data System (ADS)

    Kara, E.; Alston, W. N.; Fabian, A. C.; Cackett, E. M.; Uttley, P.; Reynolds, C. S.; Zoghbi, A.

    2016-10-01

    X-ray reverberation, where light-travel time delays map out the compact geometry around the inner accretion flow in supermassive black holes, has been discovered in several of the brightest, most variable and well-known Seyfert galaxies. In this work, we expand the study of X-ray reverberation to all Seyfert galaxies in the XMM-Newton archive above a nominal rms variability and exposure level (a total of 43 sources). Approximately 50 per cent of sources exhibit iron K reverberation, in that the broad iron K emission line responds to rapid variability in the continuum. We also find that on long time-scales, the hard band emission lags behind the soft band emission in 85 per cent of sources. This `low-frequency hard lag' is likely associated with the coronal emission, and so this result suggests that most sources with X-ray variability show intrinsic variability from the nuclear region. We update the known iron K lag amplitude versus black hole mass relation, and find evidence that the height or extent of the coronal source (as inferred by the reverberation time delay) increases with mass accretion rate.

  6. Broad Hβ Emission-line Variability in a Sample of 102 Local Active Galaxies

    NASA Astrophysics Data System (ADS)

    Runco, Jordan N.; Cosens, Maren; Bennert, Vardha N.; Scott, Bryan; Komossa, S.; Malkan, Matthew A.; Lazarova, Mariana S.; Auger, Matthew W.; Treu, Tommaso; Park, Daeseong

    2016-04-01

    A sample of 102 local (0.02 ≤ z ≤ 0.1) Seyfert galaxies with black hole masses MBH > 107M⊙ was selected from the Sloan Digital Sky Survey (SDSS) and observed using the Keck 10 m telescope to study the scaling relations between MBH and host galaxy properties. We study profile changes of the broad Hβ emission line within the three to nine year time frame between the two sets of spectra. The variability of the broad Hβ emission line is of particular interest, not only because it is used to estimate MBH, but also because its strength and width are used to classify Seyfert galaxies into different types. At least some form of broad-line variability (in either width or flux) is observed in the majority (∼66%) of the objects, resulting in a Seyfert-type change for ∼38% of the objects, likely driven by variable accretion and/or obscuration. The broad Hβ line virtually disappears in 3/102 (∼3%) extreme cases. We discuss potential causes for these changing look active galactic nuclei. While similar dramatic transitions have previously been reported in the literature, either on a case-by-case basis or in larger samples focusing on quasars at higher redshifts, our study provides statistical information on the frequency of Hβ line variability in a sample of low-redshift Seyfert galaxies.

  7. The Wasilewski sample of emission-line galaxies - Follow-up CCD imaging and spectroscopic and IRAS observations

    NASA Technical Reports Server (NTRS)

    Bothun, Gregory D.; Schmitz, Mark; Halpern, Jules P.; Lonsdale, Carol J.; Impey, Chris

    1989-01-01

    The results of an extensive imaging and spectroscopic follow-up of the objective prism-selected emission line galaxy (ELG) sample of Wasilewski (1982) are presented. Fluxes at 12, 25, 60, and 100 microns were also obtained from the coadded IRAS survey data. ELGs found by objective prism surveys are found to be generally small and underluminous galaxies which usually have higher than average optical surface brightness. The Seyfert detection rate in objective prism surveys is roughly 10 percent and the ratio of the space densities of Seyfert 2 to Seyfert 1 galaxies is significantly larger than unity. Most of the galaxies selected by objective prism surveys are star-forming, late-type spirals which often show disturbed morphology. About 25 percent of the galaxies detected by the surveys are faint, high-excitation metal-poor compact H II regions.

  8. Simultaneous Ultraviolet Line and Continuum Variability Studies in Seyfert 1 Galaxies and Quasars

    NASA Astrophysics Data System (ADS)

    Honnappa, Vijayakumar; Prabhakar, Vedavvathi

    Simultaneous Ultraviolet Line and Continuum Variability Studies in Seyfert 1 Galaxies and Quasars Vijayakumar H. Doddamani*and P. Vedavathi Department of Physics, Bangalore University, Bangalore-560056, *Corresponding author:drvkdmani@gmail.com, Abstract The line and continuum flux variability is a hallmark phenomenon of Seyfert 1 galaxies and quasars. Large amplitude luminosity variability is observed in AGNs from x-rays through radio waves over a wide-ranging timescales from minutes to years. The combinations of high luminosity and short variability time scales suggests, that the power of AGN is produced by a phenomena more efficient in terms of energy release per unit mass than ordinary stellar processes. The basic structure of AGNs thus developed based on the variability studies consists of a central super massive black hole surrounded by an accretion disk or more generally optically thick plasma radiating brightly at UV and soft X-ray wavelengths. The variability studies have been important tools of understanding the physics of the central regions of AGNs, which in general cannot be resolved with the existing or planned ground and space telescopes. Therefore, we have undertaken a study of the simultaneous ultraviolet line and continuum flux variability studies in MRK501, ESOB113-IG45 (also called as Fairall 9), MRK1506, MRK1095 V*GQCOM, PG1211+143, MRK205, PG1226+023 (also known as 3C273), PG1351+640, MRK 1383, MRK876 and QSO2251-178 as these objects have been repeatedly observed by IUE satellite over several years.. It is observed that Fairall 9, MRK 1095 and 3C273 exhibit the large amplitude variability (» 30 times) over the observed timescale, which spans several years. The remaining nine objects exhibit small amplitude (» 5 times) variability over the long time scale of observations. The highest amplitude variability is observed in Lya with a least in the MgII line. The amplitude of variability decreases in the order of Lya, CIV and Mg II, lines. These

  9. Reverberation measurements of the inner radius of the dust torus in 17 Seyfert galaxies

    SciTech Connect

    Koshida, Shintaro; Minezaki, Takeo; Yoshii, Yuzuru; Sakata, Yu; Sugawara, Shota; Kobayashi, Yukiyasu; Suganuma, Masahiro; Enya, Keigo; Tomita, Hiroyuki; Aoki, Tsutomu; Peterson, Bruce A. E-mail: minezaki@ioa.s.u-tokyo.ac.jp

    2014-06-20

    We present the results of a dust reverberation survey for 17 nearby Seyfert 1 galaxies, which provides the largest homogeneous data collection for the radius of the innermost dust torus. A delayed response of the K-band light curve after the V-band light curve was found for all targets, and 49 measurements of lag times between the flux variation of the dust emission in the K band and that of the optical continuum emission in the V band were obtained by the cross-correlation function analysis and also by an alternative method for estimating the maximum likelihood lag. The lag times strongly correlated with the optical luminosity in the luminosity range of M{sub V} = –16 to –22 mag, and the regression analysis was performed to obtain the correlation log Δt (days) = –2.11 – 0.2 M{sub V} assuming Δt∝L {sup 0.5}, which was theoretically expected. We discuss the possible origins of the intrinsic scatter of the dust lag-luminosity correlation, which was estimated to be approximately 0.13 dex, and we find that the difference of internal extinction and delayed response of changes in lag times to the flux variations could have partly contributed to intrinsic scatter. However, we could not detect any systematic change of the correlation with the subclass of the Seyfert type or the Eddington ratio. Finally, we compare the dust reverberation radius with the near-infrared interferometric radius of the dust torus and the reverberation radius of broad Balmer emission lines. The interferometric radius in the K band was found to be systematically larger than the dust reverberation radius in the same band by the about a factor of two, which could be interpreted by the difference between the flux-weighted radius and response-weighted radius of the innermost dust torus. The reverberation radius of the broad Balmer emission lines was found to be systematically smaller than the dust reverberation radius by about a factor of four to five, which strongly supports the unified

  10. THE SWIFT BURST ALERT TELESCOPE DETECTED SEYFERT 1 GALAXIES: X-RAY BROADBAND PROPERTIES AND WARM ABSORBERS

    SciTech Connect

    Winter, Lisa M.; Veilleux, Sylvain; McKernan, Barry; Kallman, T. R.

    2012-02-01

    We present results from an analysis of the broadband, 0.3-195 keV, X-ray spectra of 48 Seyfert 1-1.5 sources detected in the very hard X-rays with the Swift Burst Alert Telescope (BAT). This sample is selected in an all-sky survey conducted in the 14-195 keV band. Therefore, our sources are largely unbiased toward both obscuration and host galaxy properties. Our detailed and uniform model fits to Suzaku/BAT and XMM-Newton/BAT spectra include the neutral absorption, direct power-law, reflected emission, soft excess, warm absorption, and narrow Fe I K{alpha} emission properties for the entire sample. We significantly detect O VII and O VIII edges in 52% of our sample. The strength of these detections is strongly correlated with the neutral column density measured in the spectrum. Among the strongest detections, X-ray grating and UV observations, where available, indicate outflowing material. The ionized column densities of sources with O VII and O VIII detections are clustered in a narrow range with N{sub warm} {approx} 10{sup 21} cm{sup -2}, while sources without strong detections have column densities of ionized gas an order of magnitude lower. Therefore, we note that sources without strong detections likely have warm ionized outflows present but at low column densities that are not easily probed with current X-ray observations. Sources with strong complex absorption have a strong soft excess, which may or may not be due to difficulties in modeling the complex spectra of these sources. Still, the detection of a flat {Gamma} {approx} 1 and a strong soft excess may allow us to infer the presence of strong absorption in low signal-to-noise active galactic nucleus spectra. Additionally, we include a useful correction from the Swift BAT luminosity to bolometric luminosity, based on a comparison of our spectral fitting results with published spectral energy distribution fits from 33 of our sources.

  11. Optical polarization of the Seyfert galaxies IC 4329A and MRK 376

    NASA Technical Reports Server (NTRS)

    Martin, P. G.; Stockman, H. S.; Angel, J. R. P.; Maza, J.; Beaver, E. A.

    1982-01-01

    Measurements of the optical polarizations of the two highly polarized Seyfert 1 galaxies IC 4329A and Mrk 376 are presented. Continuum and line polarization of the two objects were observed with the Steward Observatory 2.25-m telescope using a two-channel photoelectric Pockels cell polarimeter, a single-channel scanner, and a digicon attached to a flint prism spectrograph. Results indicate that, for both galaxies, the emission line polarization and underlying continuum polarization are identical, rising toward short wavelengths, and therefore must be explained by a common mechanism. Such a mechanism is suggested to involve polarization produced by aligned grains in the galactic disk. A model for polarization in IC 4329A by this mechanism predicts a grain size three times smaller than Galactic polarizing grains, as well as a visual extinction of about 2 magnitudes, a gas to dust mass ratio close to 100 and a polarization to extinction ratio comparable to the Galactic ratio.

  12. Radio-loud narrow-line Seyfert 1 galaxies with high-velocity outflows

    NASA Astrophysics Data System (ADS)

    Komossa, S.; Xu, D.; Zensus, J. A.

    2016-02-01

    We have studied four radio-loud Narrow-line Seyfert 1 (NLS1) galaxies with extreme optical emission-line shifts, indicating radial outflow velocities of up 2450 km s-1. The shifts are accompanied by strong line broadening, up to 2270 km s-1 in [NeV]. A significant ionization stratification (higher line shift at higher ionization potential) of most ions implies that we see a large-scale wind rather than single, localized jet-cloud interactions. The observations are consistent with a scenario, where the signatures of outflows are maximized because of a pole-on view into the central engine of these radio-loud NLS1 galaxies.

  13. VizieR Online Data Catalog: Activity of the Seyfert galaxy neighbours (Koulouridis, 2013)

    NASA Astrophysics Data System (ADS)

    Koulouridis, E.; Plionis, M.; Chavushyan, V.; Dultzin, D.; Krongold, Y.; Georgantopoulos, I.; Leon-Tavares, J.

    2013-02-01

    Spectra and spectral classification of all Seyfert galaxy neighbours. Optical spectra were taken with the Boller & Chivens spectrograph mounted on the 2.1m telescope at the Observatorio Astronomico Nacional in San Pedro Martir (OAN-SPM). Observations were carried out during photometric conditions. All spectra were obtained with a 2.5" slit. The typical wavelength range was 4000-8000Å and the spectral resolution R=8Å. Spectrophotometric standard stars were observed every night. The data reduction was carried out with the IRAF package following a standard procedure. Spectra were bias-subtracted and corrected with dome flat-field frames. Arc-lamp (CuHeNeAr) exposures were used for wavelength calibration. We disentangled the spectral contribution of the host galaxy from the observed spectra by using the stellar population synthesis code STARLIGHT. (2 data files).

  14. Radiative transfer in dust and the spectral flux distribution of NGC 1068. [Seyfert galaxy

    NASA Technical Reports Server (NTRS)

    Jones, T. W.; Leung, C. M.; Gould, R. J.; Stein, W. A.

    1977-01-01

    The continuum spectral flux distribution of the Seyfert galaxy NGC 1068 is analyzed by detailed models of radiative transfer in an optically thick cloud of dust grains. For wavelengths short of 30 microns, models invoking a spherical dust cloud with visual optical depth near 10 in the nucleus of the galaxy can reproduce the observed spectrum in a way consistent with information derived from spectral lines. The far-infrared emission cannot be explained easily by dust in the nucleus, but it is hypothesized that this radiation is emitted by dust associated with the observed molecular clouds, and that these clouds lie outside the nucleus. This far-infrared emission, therefore, should be extended to the same degree as the molecular-cloud distribution. High angular resolution mapping will be necessary to confirm this hypothesis.

  15. The Mass of the Central Black Hole in the Seyfert Galaxy NGC 3783

    NASA Technical Reports Server (NTRS)

    Onken, Christopher A.; Peterson, Bradley M.

    2004-01-01

    Improved analysis of ultraviolet and optical monitoring data on the Seyfert 1 galaxy NGC 3783 provides evidence for the existence of a supermassive, (8.7 +/- 1.1) x 10(exp 6) solar mass, black hole in this galaxy. By using recalibrated spectra from the International Ultraviolet Explorer satellite and ground-based optical data, as well as refined techniques of reverberation mapping analysis, we have reduced the statistical uncertainties in the response of the emission lines to variations in the ionizing continuum. The different time lags in the emission-line responses indicate a stratification in the ionization structure of the broad-line region and are consistent with the virial relationship suggested by the analysis of similar active galaxies.

  16. Deep Optical Imaging of a Compact Group of Galaxies: Seyfert's Sextet

    NASA Astrophysics Data System (ADS)

    Nishiura, Shingo; Murayama, Takashi; Shimada, Masashi; Sato, Yasunori; Nagao, Tohru; Molikawa, Kohji; Taniguchi, Yoshiaki; Sanders, D. B.

    2000-11-01

    To investigate the dynamical status of Seyfert's Sextet (SS), we have obtained a deep optical (VR+I) image of this group. Our image shows that a faint envelope, down to a surface brightness μoptical(AB)~=27 mag arcsec-2, surrounds the member galaxies. This envelope is irregular in shape. It is likely that this shape is attributed either to recent-past or to ongoing galaxy interactions in SS. If the member galaxies have experienced a number of mutual interactions over a long timescale, the shape of the envelope should be rounder. Therefore, the irregularly shaped morphology suggests that SS is in an early phase of dynamical interaction among the member galaxies. It is interesting to note that the soft X-ray image obtained with ROSAT (Pildis, Bregman, & Evrard) is significantly similar in morphology. We discuss the possible future evolution of SS briefly.

  17. An Internet Database of Ultraviolet Continuum Light Curves for Seyfert Galaxies

    NASA Astrophysics Data System (ADS)

    Dunn, Jay P.; Jackson, Brian; Deo, Rajesh P.; Farrington, Chris; Das, Varendra; Crenshaw, D. Michael

    2006-04-01

    Using the Multimission Archive at STScI (MAST), we have extracted spectra and determined continuum light curves for 175 Seyfert galaxies that have been observed with the International Ultraviolet Explorer and the Faint Object Spectrograph on the Hubble Space Telescope. To obtain the light curves as a function of Julian Date, we used fixed bins in the object's rest frame and measured small regions (between 30 and 60 Å) of each spectrum's continuum flux in the range 1150 to 3200 Å. We provide access to the UV light curves and other basic information about the observations in tabular and graphical form via the Internet at http://www.chara.gsu.edu/PEGA/IUE.

  18. Espectroscopía infrarroja de la galaxia Seyfert NGC6300

    NASA Astrophysics Data System (ADS)

    Gaspar, G.; D‘Ambra, A.; Díaz, R. J.; Gunthardt, G.; Gómez, P.

    2015-08-01

    Here we present a spectroscopic study in the near infrared band of the active galaxy NGC 6300, with spectra obtained with the spectrograph Flamingos 2 of the telescope Gemini South. The spectra were taken in the range 1 to 2.4 mm, with a mean spatial resolution of 0.6'', in this work we present preliminary results for a single band, . This global study is based in the analysis of the relative contributions in the emission of the Seyfert nuclei and the circunnuclear star formation to discuss later the role of the AGN in the scenarios of dynamical evolution of galaxies. We present the detection of a broad component in the Pa emission line, an unexpected feature in this galaxy so far classified as a 2 type.

  19. Ultraviolet and optical spectrophotometry of the Seyfert 1.8 galaxy Markarian 609

    NASA Technical Reports Server (NTRS)

    Rudy, Richard J.; Cohen, Ross D.; Ake, T. B.

    1988-01-01

    Ultraviolet and optical observations of the Seyfert 1.8 galaxy Mrk 609 were collected simultaneously. The observations reveal strong line and continuum emission in the UV, an increase in the flux of H-beta and He I 5876, and a decrease in the H-alpha/H-beta value since the measurements by Osterbrock (1978, 1981), as well as an extended population of early-type stars, which is considered to be the source powering the larger part of the far-IR emission. Special attention is given to the origin of steep broad-line Balmer decrement measured by Osterbrock, since the strong UV continuum and the emission lines of Mrk 609 observed rule out reddening as the cause of the Balmer decrement. It is suggested that smaller-than-normal optical depths are likely to be the cause of the decrement.

  20. ESO 103-G35 - A new Seyfert galaxy and possible X-ray source

    NASA Technical Reports Server (NTRS)

    Phillips, M. M.; Feldman, F. R.; Marshall, F. E.; Wamsteker, W.

    1979-01-01

    By means of an objective prism plate, two emission-line galaxies have been identified within the 0.7-sq deg HEAO-A2 error box for the X-ray source H1834-653. Optical spectrophotometric observations are reported for both objects as well as the galaxy NGC 6684, which also lies near the position of H1834-653. These data show that one of the emission-line galaxies, ESO 103-G35, is a Seyfert galaxy with a high-excitation forbidden-line spectrum and weak broad emission wings at H-alpha. Further measurements of this galaxy reveal an infrared excess at wavelengths longer than 2.2 microns. The H-alpha luminosity of ESO 103-G35 is consistent with the X-ray luminosity estimated from the HEAO-A2 data, thus strengthening the likelihood of association of this galaxy with the X-ray emission.

  1. Modelling of the X-ray broad absorption features in Narrow-Line Seyfert 1s

    NASA Astrophysics Data System (ADS)

    Porquet, Delphine; Mouchet, Martine; Dumont Anne-Marie

    2000-09-01

    We investigate the origin of the broad absorption features detected near 1-1.4 keV in several Narrow-Line Seyfert 1 galaxies, by modelling the absorbing medium with various physical parameters, using the ionization code PEGAS. The observed properties of the X-ray absorption features can be reproduced by taking into account the peculiar soft X-ray excess which is well fitted by a blackbody plus an underlying power law. We equally stress that the emission coming from the absorbing medium (related to the covering factor) has a strong influence on the resulting X-ray spectrum, in particular on the apparent position and depth of the absorption features. A non-solar iron abundance may be required to explain the observed deep absorption. We also investigate the influence of an additional collisional ionization process ("hybrid case") on the predicted absorption features.

  2. Perfiles de luminosidad en galaxias con núcleo tipo Seyfert 1

    NASA Astrophysics Data System (ADS)

    Boris, N.; Rodriguez-Ardilla, A. A.; Pastoriza, M. G.

    Presentamos imágenes CCD en los filtros BVI y Hα de una muestra de 10 galaxias Seyfert 1 y Narrow Line Seyfert 1. Recientes observaciones muestran que hay una diferencia significante en el índice espectral óptico entre NLS1s y Sy1 normales, siendo para las primeras del orden de 2. Otra característica importante es que la mayor parte de las NLS1s muestran tasas de FeII/Hβ mayores que las observadas en otras Sy1s. Desde el punto de vista fotométrico, estas galaxias no tienenningún tipo de estudio previo. Presentamos magnitudes totales, perfiles de luminosidad y mapas de color junto con un detallado análisis de la formación estelar en estos objetos. Encontramos que la descomposición en bulbo + disco representa adecuadamente los perfiles de luminosidad de las galaxias de la muestra. Sin embargo, en todos los casos es necesario que el disco tenga un agujero en su centro. El radio de este agujero va desde los 3 a los 9 kpc. Si bien no tenemos aún una explicación para este hecho, los agujeros parecen estar asociados a anillos circumnucleares de alto oscurecimiento E(B-V) ~1. Los perfiles presentan también un fuerte gradiente de color, siendo notablemente más azules hacia la región nuclear. Los objetos de la muestra cubren todo el rango de tipos morfológicos, no obstante, no encontramos regiones de formación estelar en las regiones exteriores de las galaxias. La formación estelar está confinada a la región nuclear y se data en alrededor de 5 x 107 años.

  3. The new primary X-ray component confirmed in the Seyfert I galaxy IC 4329A

    NASA Astrophysics Data System (ADS)

    Miyake, Katsuma; Noda, Hirofumi; Yamada, Shin'ya; Makishima, Kazuo; Nakazawa, Kazuhiro

    2016-06-01

    The bright and highly variable Seyfert I active galactic nucleus IC 4329A was observed with Suzaku five times in 2007 August, with intervals of ˜5 days and a net exposure of 24-31 ks each. Another longer observation was carried out in 2012 August with a net exposure of 118 ks. In the six observations, a source was detected in 2-45 keV with an average 2-10 keV fluxes of (0.67-1.2) × 10-10 erg cm-2 s-1. Its intensity changed by a factor of 2 among the five observations in 2007, and 1.5 within the 2012 observation. A difference of spectrum among these observations revealed that the variability of IC 4329A was carried mainly by a power-law component with a photon index Γ ˜ 2.0. However, in addition to this primary component and its associated reflection, the broad-band Suzaku data required another, harder, and less-variable component with Γ ˜ 1.4. The presence of this new continuum was also confirmed by analyzing the same six data sets through the spectral decomposition technique developed by Noda et al. (2013a, ApJ, 771, 100). This Γ ˜ 1.4 continuum is considered to be a new primary component that has not been recognized in the spectra of IC 4329A so far, although it was recently identified in those of several other Seyfert I galaxies (Noda et al. 2013a, ApJ, 771, 100; Noda et al. 2014, ApJ, 794, 2).

  4. RXTE Observations of the Seyfert 2 Galaxy MrK 348

    NASA Technical Reports Server (NTRS)

    Smith, David A.; Georgantopoulos, Ioannis; Warwick, Robert S.

    2000-01-01

    We present RXTE monitoring observations of the Seyfert 2 galaxy Mrk 348 spanning a 6 month period. The time-averaged spectrum in the 3-20 keV band shows many features characteristic of a Compton-thin Seyfert 2 galaxy, namely a hard underlying power-law continuum (Gamma approximately equal 1.8) with heavy soft X-ray absorption (N(sub H) approximately 10(exp 23)/sq cm) plus measurable iron K.alpha emission (equivalent width approximately 100 eV) and, at high energy, evidence for a reflection component (R approximately < 1). During the first half of the monitoring period the X-ray continuum flux from Mrk 348 remained relatively steady. However this was followed by a significant brightening of the source (by roughly a factor of 4) with the fastest change corresponding to a doubling of its X-ray flux on a timescale of about 20 days. The flux increase was accompanied by a marked softening of X-ray spectrum most likely attributable to a factor approximately 3 decline in the intrinsic line-of-sight column density. In contrast the iron K.alpha line and the reflection components showed no evidence of variability. These observations suggest a scenario in which the central X-ray source is surrounded by a patchy distribution of absorbing material located within about a light-week of the nucleus of Mrk 348. The random movement of individual clouds within the absorbing screen, across our line of sight, produces substantial temporal variations in the measured column density on timescales of weeks to months and gives rise to the observed X-ray spectral variability. However, as viewed from the nucleus the global coverage and typical thickness of the cloud layer remains relatively constant.

  5. X-ray versus Optical Variations in the Seyfert 1 Nucleus NGC 3516: A Puzzling Disconnectedness

    NASA Technical Reports Server (NTRS)

    Maoz, Dan; Markowitz, Alex; Edelson, Rick; Nandra, Kirpal; White, Nicholas E. (Technical Monitor)

    2002-01-01

    We present optical broadband (B and R) observations of the Seyfert 1 nucleus NGC 3516, obtained at Wise Observatory from March 1997 to March 2002, contemporaneously with X-ray 2-10 keV measurements with RXTE. With these data we increase the temporal baseline of this dataset to 5 years, more than triple to the coverage we have previously presented for this object. Analysis of the new data does not confirm the 100-day lag of X-ray behind optical variations, tentatively reported in our previous work. Indeed, excluding the first year's data, which drive the previous result, there is no significant correlation at any Lag between the X-ray and optical bands. We also find no correlation at any lag between optical flux and various X-ray hardness ratios. We conclude that the close relation observed between the bands during the first year of our program was either a fluke, or perhaps the result of the exceptionally bright state of NGC 3516 in 1997, to which it has yet to return. Reviewing the results of published joint X-ray and UV/optical Seyfert monitoring programs, we speculate that there are at least two components or mechanisms contributing to the X-ray continuum emission up to 10 key: a soft component that is correlated with UV/optical variations on timescales approx. greater than 1 day, and whose presence can be detected when the source is observed at low enough energies (approx. 1 keV), is unabsorbed, or is in a sufficiently bright phase; and a hard component whose variations are uncorrelated with the UV/optical.

  6. A JET MODEL FOR THE BROADBAND SPECTRUM OF THE SEYFERT 1 GALAXY NGC 4051

    SciTech Connect

    Maitra, Dipankar; Miller, Jon M.; King, Ashley; Markoff, Sera

    2011-07-10

    Recent radio very long baseline interferometry observations of the {approx} parsec-scale nuclear region of the narrow line Seyfert 1 galaxy NGC 4051 hint toward the presence of outflowing plasma. From available literature we have collected high-quality, high-resolution broadband spectral energy distribution (SED) data of the nuclear region of NGC 4051 spanning from radio through X-rays, to test whether the broadband SED can be explained within the framework of a relativistically outflowing jet model. We show that once the contribution from the host galaxy is taken into account, the broadband emission from the active galactic nucleus (AGN) of NGC 4051 can be well described by the jet model. Contributions from dust and ongoing star formation in the nuclear region tend to dominate the IR emission even at the highest resolutions. In the framework of the jet model, the correlated high variability of the extreme-ultraviolet and X-rays compared to other wavelengths suggests that the emission at these wavelengths is optically thin synchrotron originating in the particle acceleration site(s) in the jet very close (few r{sub g}= GM{sub BH}/c{sup 2}) to the central supermassive black hole of mass M{sub BH}. Our conclusions support the hypothesis that narrow line Seyfert 1 galaxies (which NGC 4051 is a member of) harbor a 'jetted' outflow with properties similar to what has already been seen in low-luminosity AGNs and stellar mass black holes in hard X-ray state.

  7. SUBMILLIMETER LINE SPECTRUM OF THE SEYFERT GALAXY NGC 1068 FROM THE HERSCHEL-SPIRE FOURIER TRANSFORM SPECTROMETER

    SciTech Connect

    Spinoglio, Luigi; Pereira-Santaella, Miguel; Busquet, Gemma; Schirm, Maximilien R. P.; Wilson, Christine D.; Parkin, Tara J.; Glenn, Jason; Kamenetzky, Julia; Rangwala, Naseem; Maloney, Philip R.; Bendo, George J.; Madden, Suzanne C.; Boselli, Alessandro; Cooray, Asantha; Page, Mathew J.

    2012-10-20

    The first complete submillimeter spectrum (190-670 {mu}m) of the Seyfert 2 galaxy NGC 1068 has been observed with the SPIRE Fourier transform spectrometer on board the Herschel Space Observatory. The sequence of CO lines (J {sub up} = 4-13), lines from H{sub 2}O, the fundamental rotational transition of hydrogen fluoride, two o-H{sub 2}O{sup +} lines, and one line each from CH{sup +} and OH{sup +} have been detected, together with the two [C I] lines and the [N II] 205 {mu}m line. The observations in both single pointing mode with sparse image sampling and in mapping mode with full image sampling allow us to disentangle two molecular emission components, one due to the compact circumnuclear disk (CND) and one from the extended region encompassing the star-forming ring (SF-ring). Radiative transfer models show that the two CO components are characterized by densities of n(H{sub 2}) = 10{sup 4.5} and 10{sup 2.9} cm{sup -3} and temperatures of T {sub kin} = 100 K and 127 K, respectively. A comparison of the CO line intensities with the photodissociation region (PDR) and X-ray-dominated region (XDR) models, together with the other observational constraints, such as the observed CO surface brightness and the radiation field, indicates that the best explanation for the CO excitation of the CND is an XDR with a density of n(H{sub 2}) {approx} 10{sup 4} cm{sup -3} and an X-ray flux of 9 erg s{sup -1} cm{sup -2}, consistent with illumination by the active galactic nucleus, while the CO lines in the SF-ring are better modeled by a PDR. The detected water transitions, together with those observed with the Herschel PACS spectrometer, can be modeled by a large velocity gradient model with low temperature (T {sub kin} {approx} 40 K) and high density (n(H{sub 2}) in the range 10{sup 6.7}-10{sup 7.9} cm{sup -3}). The emission of H{sub 2}O{sup +} and OH{sup +} are in agreement with PDR models with cosmic-ray ionization. The diffuse ionized atomic component observed through the [N

  8. Submillimeter Line Spectrum of the Seyfert Galaxy NGC 1068 from the Herschel-SPIRE Fourier Transform Spectrometer

    NASA Astrophysics Data System (ADS)

    Spinoglio, Luigi; Pereira-Santaella, Miguel; Busquet, Gemma; Schirm, Maximilien R. P.; Wilson, Christine D.; Glenn, Jason; Kamenetzky, Julia; Rangwala, Naseem; Maloney, Philip R.; Parkin, Tara J.; Bendo, George J.; Madden, Suzanne C.; Wolfire, Mark G.; Boselli, Alessandro; Cooray, Asantha; Page, Mathew J.

    2012-10-01

    The first complete submillimeter spectrum (190-670 μm) of the Seyfert 2 galaxy NGC 1068 has been observed with the SPIRE Fourier transform spectrometer on board the Herschel Space Observatory. The sequence of CO lines (J up = 4-13), lines from H2O, the fundamental rotational transition of hydrogen fluoride, two o-H2O+ lines, and one line each from CH+ and OH+ have been detected, together with the two [C I] lines and the [N II] 205 μm line. The observations in both single pointing mode with sparse image sampling and in mapping mode with full image sampling allow us to disentangle two molecular emission components, one due to the compact circumnuclear disk (CND) and one from the extended region encompassing the star-forming ring (SF-ring). Radiative transfer models show that the two CO components are characterized by densities of n(H2) = 104.5 and 102.9 cm-3 and temperatures of T kin = 100 K and 127 K, respectively. A comparison of the CO line intensities with the photodissociation region (PDR) and X-ray-dominated region (XDR) models, together with the other observational constraints, such as the observed CO surface brightness and the radiation field, indicates that the best explanation for the CO excitation of the CND is an XDR with a density of n(H2) ~ 104 cm-3 and an X-ray flux of 9 erg s-1 cm-2, consistent with illumination by the active galactic nucleus, while the CO lines in the SF-ring are better modeled by a PDR. The detected water transitions, together with those observed with the Herschel PACS spectrometer, can be modeled by a large velocity gradient model with low temperature (T kin ~ 40 K) and high density (n(H2) in the range 106.7-107.9 cm-3). The emission of H2O+ and OH+ are in agreement with PDR models with cosmic-ray ionization. The diffuse ionized atomic component observed through the [N II] 205 μm line is consistent with previous photoionization models of the starburst. Herschel is an ESA space observatory with science instruments provided by

  9. CONTRIBUTION OF THE ACCRETION DISK, HOT CORONA, AND OBSCURING TORUS TO THE LUMINOSITY OF SEYFERT GALAXIES: INTEGRAL AND SPITZER OBSERVATIONS

    SciTech Connect

    Sazonov, S.; Churazov, E.; Krivonos, R.; Revnivtsev, M.; Sunyaev, R.; Vikhlinin, A.; Hickox, R. C.; Gorjian, V.; Werner, M. W.; Fabian, A. C.; Forman, W. R.

    2012-10-01

    We estimate the relative contributions of the supermassive black hole (SMBH) accretion disk, corona, and obscuring torus to the bolometric luminosity of Seyfert galaxies, using Spitzer mid-infrared (MIR) observations of a complete sample of 68 nearby active galactic nuclei (AGNs) from the INTEGRAL all-sky hard X-ray (HX) survey. This is the first HX-selected (above 15 keV) sample of AGNs with complementary high angular resolution, high signal-to-noise, MIR data. Correcting for the host galaxy contribution, we find a correlation between HX and MIR luminosities: L{sub 15{mu}m}{proportional_to}L{sup 0.74{+-}0.06}{sub HX}. Assuming that the observed MIR emission is radiation from an accretion disk reprocessed in a surrounding dusty torus that subtends a solid angle decreasing with increasing luminosity (as inferred from the declining fraction of obscured AGNs), the intrinsic disk luminosity, L{sub Disk}, is approximately proportional to the luminosity of the corona in the 2-300 keV energy band, L{sub Corona}, with the L{sub Disk}/L{sub Corona} ratio varying by a factor of 2.1 around a mean value of 1.6. This ratio is a factor of {approx}2 smaller than for typical quasars producing the cosmic X-ray background. Therefore, over three orders of magnitude in luminosity, HX radiation carries a large, and roughly comparable, fraction of the bolometric output of AGNs. We estimate the cumulative bolometric luminosity density of local AGNs at {approx}(1-3) Multiplication-Sign 10{sup 40} erg s{sup -1} Mpc{sup -3}. Finally, the Compton temperature ranges between kT{sub c} Almost-Equal-To 2 and Almost-Equal-To 6 keV for nearby AGNs, compared to kT{sub c} Almost-Equal-To 2 keV for typical quasars, confirming that radiative heating of interstellar gas can play an important role in regulating SMBH growth.

  10. RAPID INFRARED VARIABILITY OF THREE RADIO-LOUD NARROW-LINE SEYFERT 1 GALAXIES: A VIEW FROM THE WIDE-FIELD INFRARED SURVEY EXPLORER

    SciTech Connect

    Jiang Ning; Zhou Hongyan; Wang Tinggui; Dong Xiaobo; Jiang Peng; Ho, Luis C.; Yuan Weimin; Ji Tuo; Tian Qiguo

    2012-11-10

    Using newly released data from the Wide-field Infrared Survey Explorer, we report the discovery of rapid infrared variability in three radio-loud narrow-line Seyfert 1 galaxies (NLS1s) selected from the 23 sources in the sample of Yuan et al. J0849+5108 and J0948+0022 clearly show intraday variability, while J1505+0326 has a longer measurable timescale within 180 days. Their variability amplitudes, corrected for measurement errors, are {approx}0.1-0.2 mag. The detection of intraday variability restricts the size of the infrared-emitting region to {approx}10{sup -3} pc, significantly smaller than the scale of the torus but consistent with the base of a jet. The three variable sources are exceptionally radio-loud, have the highest radio brightness temperature among the whole sample, and all show detected {gamma}-ray emission in Fermi/LAT observations. Their spectral energy distributions resemble those of low-energy-peaked blazars, with a synchrotron peak around infrared wavelengths. This result strongly confirms the view that at least some radio-loud NLS1s are blazars with a relativistic jet close to our line of sight. The beamed synchrotron emission from the jet contributes significantly to and probably dominates the spectra in the infrared and even optical bands.

  11. The UV to hard X-ray continuum of a Seyfert galaxy scrutinized by XMM and NuSTAR

    NASA Astrophysics Data System (ADS)

    Petrucci, Pierre-Olivier

    2013-10-01

    We propose to perform a unique XMM-NuSTAR monitoring with 5 repeated observations of 20 ks spaced by a few days of the Seyfert galaxy NGC 4593. This is the best Seyfert candidate to obtain high sensitivity measurements on a day time scale over the entire high energy spectrum. This is an absolute prerequisite 1) to correctly disentangle the different spectral components present in this energy band, and 2) to reveal their complex interdependences and variability behavior. This study will allow us i) to constrain the physical parameters of the Comptonizing corona; ii) to investigate the nature of the soft X-ray excess; iii) to put firm conclusions on the distance, nature and geometry of the reflecting material(s).

  12. 0714 - 2914 (M4-1) - Another Seyfert galaxy with aligned radio continuum and optical emission-line morphologies

    NASA Technical Reports Server (NTRS)

    Wilson, A. S.; Baldwin, J. A.

    1989-01-01

    Direct imaging and long-slit spectroscopic mapping of the emission-line gas in the Seyfert 2 galaxy 0714 - 2914 (M4-1, MCG - 5-18-2) are reported. The nuclear regions contain an extended (1 kpc size), high-excitation nebulosity that is well aligned with the jet-like nonthermal radio source. The profiles of Forbidden O III 5007A are asymmetric, with extended red wings to the north and west of the nucleus and extended blue wings to the south and east. This switch in the sense of asymmetry is accounted for in terms of a combination of normal rotational motions in the galaxy disk and high-velocity outflow or infall associated with the Seyfert activity.

  13. X-Ray Observations of PKS 0558-504: A Test of Models for Narrow-Line Seyfert 1 Galaxies

    NASA Technical Reports Server (NTRS)

    Leighly, Karen

    1999-01-01

    ROSAT observations of narrow-line Seyfert 1 galaxies find a very steep soft spectrum and rapid variability. It has been suggested that these properties result from an extreme value of a yet unknown physical parameter; a high accretion rate, low black hole mass or face-on orientation have been suggested. During a Ginga observation of bright NLS1 PKS 0558-504, a flare was observed with rise time so rapid for this luminous object that the emission must be beamed. If reconfirmed, this behavior would support, the face-oil orientation model. PKS 0558-504 is one of the few NLS1s known to be bright enough above 10 keV that good spectral constraints on the reflection component, common in broad-line Seyfert 1s, is possible. A 60ks RXTE observation was performed; however, we failed to detect any large amplitude flares.

  14. Cinemática y masas de agujeros negros en galaxias activas del tipo "Narrow Line Seyfert 1"

    NASA Astrophysics Data System (ADS)

    Oío, G.; Schmidt, E.; Vega Neme, L. R.

    We apply a spectral synthesis method to Narrow Line Seyfert 1 active galax- ies with public spectra available. Our goal will be to obtain the stellar ve- locity dispersions, and then the central black hole masses via the Tremaine relation. We comment several problems we found in fitting this type of objects and the possibility of obtaining masses through the emission lines. FULL TEXT IN SPANISH

  15. Spectral evolution of active galactic nuclei Penrose Compton scattering processes and gamma ray emission from Seyfert galaxies

    NASA Technical Reports Server (NTRS)

    Leiter, Darryl; Boldt, Elihu

    1990-01-01

    In black hole spectral evolution models for active galactic nuclei (AGN), present epoch Seyfert galaxies evolve from an earlier precursor active galaxy (PAG) stage at redshift z is approximately 7 where they acted as the thermal sources responsible for the residual cosmic x ray background (RCXB). The Seyfert galaxies which emerge in this context emit Penrose Compton Scattering (PCS) gamma ray transients on the order of hours with a kinematic cutoff in the spectrum less than or equal to 3 MeV. The EGRET (Energetic Gamma-Ray Experimental Telescope/ OSSE (Oriented Scintillation Spectrometer Experiment/ COMPTEL (Compton Telescope)/ BATSE (Burst and Transient Source Experiment) instruments on the Gamma Ray Observatory (GRO) are appropriate instruments to carry out further tests of this model by studying: PCS gamma ray transient emission from individual galaxies and, the possibility that present epoch PCS gamma ray emitting Seyfert galaxies contribute observable temporal variability to the excess diffuse gamma ray background component less than or equal to 3 MeV.

  16. XMM-Newton long-look observation of the narrow line Seyfert 1 galaxy PKS 0558-504. I. Spectral analysis

    NASA Astrophysics Data System (ADS)

    Papadakis, I. E.; Brinkmann, W.; Gliozzi, M.; Raeth, C.; Nicastro, F.; Conciatore, M. L.

    2010-02-01

    Context. PKS 0558-504 has been observed repeatedly by XMM-Newton as a calibration and performance verification (PV) target. In this work, we present results from the spectral analysis of a long XMM-Newton observation of the radio loud Narrow Line Seyfert 1 galaxy PKS 0558-504. Aims: To study the soft excess component in this object, the spectral variations it exhibits in both the hard and soft X-ray bands, and their correlation. Methods: We used mainly the PN data, and we fitted various spectral models to the time average spectra of the individual orbits as well as the spectra from data segments of shorter duration. We also used the RGS data to search for signs of a warm absorber in the source. Results: The source is highly variable, on all sampled time scales. We did not observe any absorption features in either the soft or hard band. We found weak evidence for the presence of an iron line at ~6.8 keV, which is indicative of emission from highly ionized iron. The 2-10 keV band spectrum of the source is well fitted by a simple power law model, whose slope steepens with increasing flux, similar to what is observed in other Seyferts as well. The soft excess is variable both in flux and shape, and it can be well described by a low-temperature Comptonisation model, whose slope flattens with increasing flux. Finally, the soft excess flux variations are moderately correlated with the hard band variations, and we found weak evidence that they are leading them by ~20 ks. Conclusions: Our results rule out a jet origin for the bulk of the X-ray emission in this object. We found no signals of a warm absorber. The observed hard band spectral variations suggest intrinsic continuum slope variations, caused by changes in the “heating/cooling” ratio of the hot corona. The low-temperature Comptonising medium, responsible for the soft excess emission, could be a hot layer in the inner disc of the source, which appears due to the fact that the source is accreting at a super

  17. Gamma-ray activity of Seyfert galaxies and constraints on hot accretion flows

    NASA Astrophysics Data System (ADS)

    Wojaczyński, Rafał; Niedźwiecki, Andrzej; Xie, Fu-Guo; Szanecki, Michał

    2015-12-01

    Aims: We check how the Fermi/LAT data constrain the physics of hot accretion flows that are most likely present in low-luminosity AGNs. Methods: Using a precise model of emission from hot flows, we studied the flow γ-ray emission resulting from proton-proton interactions. We explored the dependence of the γ-ray luminosity on the accretion rate, the black hole spin, the magnetic field strength, the electron heating efficiency, and the particle distribution. Then, we compared the hadronic γ-ray luminosities predicted by the model for several nearby Seyfert 1 galaxies with the results of our analysis of 6.4 years of Fermi/LAT observations of these AGNs. Results: In agreement with previous studies, we find a significant γ-ray detection in NGC 6814. We were only able to derive upper limits for the remaining objects, although we report marginally significant (~3σ) signals at the positions of NGC 4151 and NGC 4258. The derived upper limits for the flux above 1 GeV allow us to constrain the proton acceleration efficiency in flows with heating of electrons dominated by Coulomb interactions, which case is favored by the X-ray spectral properties. In these flows, at most ~10% of the accretion power can be used for a relativistic acceleration of protons. Upper limits for the flux below 1 GeV can constrain the magnetic field strength and black hole spin value; we find these constraints for NGC 7213 and NGC 4151. We also note that the spectral component above ~4 GeV previously found in the Fermi/LAT data of Centaurus A may be due to hadronic emission from a flow within the above constraint. We rule out this origin of the γ-ray emission for NGC 6814. For models with a strong magnetohydrodynamic heating of electrons, the hadronic γ-ray fluxes are below the Fermi/LAT sensitivity even for the closest AGNs. In these models, nonthermal Compton radiation may dominate in the γ-ray range if electrons are efficiently accelerated and the acceleration index is hard; for the index

  18. Infrared identification of IGR J09026-4812 as a Seyfert 1 galaxy

    NASA Astrophysics Data System (ADS)

    Zurita Heras, J. A.; Chaty, S.; Tomsick, J. A.

    2009-08-01

    Context: IGR J09026-4812 was discovered by INTEGRAL in 2006 as a new hard X-ray source. Thereafter, an observation with Chandra pinpointed a single X-ray source within the ISGRI error circle, showing a hard spectrum, and improving its high-energy localisation to a subarcsecond accuracy. Thus, the X-ray source was associated with the infrared counterpart 2MASS J09023731-4813339 whose JHKS photometry indicated a highly reddened source. The high-energy properties and the counterpart photometry suggested a high-mass X-ray binary with a main sequence companion star located 6.3-8.1 kpc away and with a 0.3-10 keV luminosity of 8-1^+13 × 1034 erg s-1. Aims: New optical and infrared observations were needed to confirm the counterpart and to reveal the nature of IGR J09026-4812. Methods: We performed optical and near infrared observations on the counterpart 2MASS J09023731-4813339 with the ESO/NTT telescope on March 2007. We carried out photometry and spectroscopy in near infrared wavelengths and photometry in optical wavelengths. Results: The accurate astrometry at both optical and near infrared wavelengths confirmed 2MASS J09023731-4813339 as the counterpart of IGR J09026-4812. However, the near infrared images show that the source is extended, thus excluding the possibility of a Galactic compact source. The source spectrum shows three main emission lines identified as the HeI λ1.0830~μm line, and the HI Pa β and Pa α lines, typical of galaxies with an active galactic nucleus. The broadness of these lines reached values as large as 4000 km s-1, suggesting a type 1 Seyfert galaxy. The redshift of the source is z = 0.0391 ± 0.0004. Thus, the near infrared photometry and spectroscopy allowed us to classify IGR J09026-4812 as a type 1 Seyfert galaxy. Based on observations made with ESO Telescopes at the La Silla Observatory under programme ID 078.D-0268(B).

  19. The Detection of Circumnuclear X-Ray Emission from the Seyfert Galaxy NGC 3516

    NASA Technical Reports Server (NTRS)

    George, I. M.; Turner, T. J.; Netzer, H.; Kraemer, S. B.; Ruiz, J.; Chelouche, D.; Crenshaw, D. M.; Yaqoob, T.; Nandra, K.; Mushotzky, R. F.; White, Nicholas E. (Technical Monitor)

    2001-01-01

    We present the first high-resolution, X-ray image of the circumnuclear regions of the Seyfert 1 galaxy NGC 3516, using the Chandra X-ray Observatory (CXO). All three of the CXO observations reported were performed with one of the two grating assemblies in place, and here we restrict our analysis to undispersed photons (i.e. those detected in the zeroth-order). A previously-unknown X-ray source is detected approximately 6 arcsec (1.1h(sub 75)(exp -1) kpc) NNE of the nucleus (position angle approximately 29 degrees) which we designate CXOU 110648.1 + 723412. Its spectrum can be characterized as a power law with a photon index (Gamma) approximately 1.8 - 2.6, or as thermal emission with a temperature kT approximately 0.7 - 3 keV. Assuming a location within NGC 3516, isotropic emission implies a luminosity L approximately 2 - 8 x 10(exp 39)h(sub 75)(exp-2) erg s(exp -1) in the 0.4 - 2 keV band. If due to a single point source, the object is super-Eddington for a 1.4 solar mass neutron star. However, multiple sources or a small, extended source cannot be excluded using the current data. Large-scale extended S-ray emission is also detected out to approximately 10 arcsec (approximately 2h(sub 75)(exp -1) kpc) from the nucleus to the NE and SW, and is approximately aligned with the morphologies of the radio emission and extended narrow emission line region (ENLR). The mean luminosity of this emission is 1 - 5 x 10(exp 37)h(sub 75)(exp -2) erg s(exp -1) arcsec(exp -2), in the 0.4 - 2 keV band. Unfortunately the current data cannot usefully constrain its spectrum. These results are consistent with earlier suggestions of circumnuclear X-ray emissi in NGC 3516 based on ROSAT observations, and thus provide the first clear detection of extended X-ray emission in a Seyfert 1.0 galaxy. If the extended emission is due to scattering of the nuclear X-ray continuum, then the pressure in the X-ray emitting gas is at least two orders of magnitude too small to provide the confining

  20. VLBI IMAGING OF THE DOUBLE PEAKED EMISSION LINE SEYFERT KISSR 1494

    SciTech Connect

    Kharb, P.; Das, M.; Subramanian, S.; Chitta, L. P.; Paragi, Z.

    2015-02-01

    We present here the results from dual-frequency phase-referenced Very Long Baseline Interferometry observations of the Seyfert galaxy KISSR 1494, which exhibits double peaked emission lines in its Sloan Digital Sky Survey spectrum. We detect a single radio component at 1.6 GHz, but not at 5 GHz, implying a spectral index steeper than –1.5 ± 0.5 (S {sub ν}∝ν{sup α}). The high brightness temperature of the radio component (∼1.4 × 10{sup 7} K) and the steep radio spectrum support a non-thermal synchrotron origin. A crude estimate of the black hole mass derived from the M {sub BH}-σ{sub *} relation is ∼1.4 ± 1.0 × 10{sup 8} M {sub ☉}; it is accreting at an Eddington rate of ∼0.02. The radio data are consistent with either the radio emission coming from the parsec-scale base of a synchrotron wind originating in the magnetized corona above the accretion disk, or from the inner ionized edge of the accretion disk or torus. In the former case, the narrow line region (NLR) clouds may form a part of the broad outflow, while in the latter, the NLR clouds may form a part of an extended disk beyond the torus. The radio and NLR emission may also be decoupled so that the radio emission originates in an outflow while the NLR is in a disk and vice versa. While with the present data it is not possible to clearly distinguish between these scenarios, there appears to be greater circumstantial evidence supporting the coronal wind picture in KISSR 1494. From the kiloparsec-scale radio emission, the time-averaged kinetic power of this outflow is estimated to be Q ≈ 1.5 × 10{sup 42} erg s{sup –1}, which is typical of radio outflows in low-luminosity active galactic nuclei. This supports the idea that radio ''jets'' and outflowing coronal winds are indistinguishable in Seyfert galaxies.

  1. Similarity of jet radiation between flat spectrum radio quasars and GeV narrow-line Seyfert 1 galaxies: a universal δ-L c correlation

    NASA Astrophysics Data System (ADS)

    Zhu, Yong-Kai; Zhang, Jin; Zhang, Hai-Ming; Liang, En-Wei; Yan, Da-Hai; Cui, Wei; Zhang, Shuang-Nan

    2016-11-01

    By modeling the broadband spectral energy distributions (SEDs) of a typical flat spectrum radio quasar (FSRQ, 3C 279) and two GeV narrow-line Seyfert 1 galaxies (NLS1s, PMN J0948+0022 and 1H 0323+342) in different flux stages with one-zone leptonic models, we find a universal correlation between their Doppler factors (δ) and peak luminosities (L c) of external Compton scattering bumps. Compiling a combined sample of FSRQs and GeV NLS1s, it is found that both FSRQs and GeV NLS1s in different stages and in different sources follow the same δ-L c correlation well. This indicates that the variations of observed luminosities may be essentially due to the Doppler boosting effect. The universal δ-L c relation between FSRQs and GeV NLS1s in different stages may be further evidence that the particle acceleration and radiation mechanisms for the two kinds of sources are similar. In addition, by replacing L c with the observed luminosity in the Fermi/LAT band (L LAT), this correlation holds and it may serve as an empirical indicator of δ. We estimate the δ values with L LAT for 484 FSRQs in the Fermi/LAT Catalog and they range from 3 to 41, with a median of 16, which are statistically consistent with the values derived by other methods.

  2. Spitzer/IRS Observations of Seyfert 1.8 and 1.9 Galaxies: Probing the Dusty Torus at Intermediate Viewing Angles

    NASA Astrophysics Data System (ADS)

    Kraemer, Steven; Crenshaw, Michael; Dietrich, Matthias; Elitzur, Moshe; Gull, Theodore; Teplitz, Harry; Turner, Jane

    2004-09-01

    According to the unified model for AGN, Seyfert 1.8 and 1.9 galaxies are viewed at inclinations between those of Seyfert 1s (face-on) and Seyfert 2s (edge-on) with respect to the source of obscuration, typically envisioned as a dusty torus. This view is supported by the weak broad emission-line components of the Balmer lines, with ratios that are consistent with significant (E(B-V} ~ 1 mag) reddening of the broad-line region. Mid-IR spectra are the only means with which to probe the circumnuclear gas in these intermediate Seyferts and constrain the physical structure of the torus, such as its size, scale height, and clumpiness. Seyfert 1.8s and 1.9s also tend to possess relatively weak high ionization narrow lines (e.g. [Fe~VII] 6087 A) compared to Seyfert 1s, suggesting that the dusty circumnuclear gas may also obscure the inner narrow line region. We request Spitzer IRS spectra of 12 Seyfert 1.8s and 1.9s in order to 1) determine the temperature of the dust, and hence its radial distance from the central engine, to test for a torus origin, 2) determine the scale height and clumpiness of the torus atmosphere via the silicate 10 feature and comparisons with clumpy torus models, and 3) penetrate the obscuring gas via mid-IR emission lines, such as [Ne~V] 14.3 microns and [O~IV] 25.9 microns, to reveal the hidden high-ionization inner narrow line region. We have selected targets with host galaxies that are close to face-on, to minimize contamination of the mid-IR spectra by dust in their galactic planes. Among the more than 60 Seyferts in the Spitzer/IRS reserved target catalog, there are only a handful of true Seyfert 1.8s and 1.9s, and all of these have inclined (b/a < 0.5 ) host galaxies.

  3. A FANAROFF-RILEY TYPE I CANDIDATE IN NARROW-LINE SEYFERT 1 GALAXY Mrk 1239

    SciTech Connect

    Doi, Akihiro; Wajima, Kiyoaki; Hagiwara, Yoshiaki; Inoue, Makoto

    2015-01-10

    We report finding kiloparsec-scale radio emissions aligned with parsec-scale jet structures in the narrow-line Seyfert 1 (NLS1) galaxy Mrk 1239 using the Very Large Array and the Very Long Baseline Array. Thus, this radio-quiet NLS1 has a jet-producing central engine driven by essentially the same mechanism as that of other radio-loud active galactic nuclei (AGNs). Most of the radio luminosity is concentrated within 100 parsecs and overall radio morphology looks edge-darkened; the estimated jet kinetic power is comparable to Fanaroff-Riley Type I radio galaxies. The conversion from accretion to jet power appears to be highly inefficient in this highly accreting low-mass black hole system compared with that in a low-luminosity AGN with similar radio power driven by a sub-Eddington, high-mass black hole. Thus, Mrk 1239 is a crucial probe to the unexplored parameter spaces of central engines for a jet formation.

  4. A TWO-PHASE LOW-VELOCITY OUTFLOW IN THE SEYFERT 1 GALAXY Ark 564

    SciTech Connect

    Gupta, A.; Mathur, S.; Krongold, Y.; Nicastro, F.

    2013-05-10

    The Seyfert 1 galaxy Ark 564 was observed with Chandra high-energy transmission gratings for 250 ks. We present the high-resolution X-ray spectrum that shows several associated absorption lines. The photoionization model requires two warm absorbers (WAs) with two different ionization states (log U = 0.39 {+-} 0.03 and log U = -0.99 {+-} 0.13), both with moderate outflow velocities ({approx}100 km s{sup -1}) and relatively low line of sight column densities (log N{sub H} = 20.94 and 20.11 cm{sup -2}). The high-ionization phase produces absorption lines of O VII, O VIII, Ne IX, Ne X, Mg XI, Fe XVII, and Fe XVIII, while the low-ionization phase produces lines at lower energies (O VIand O VII). The pressure-temperature equilibrium curve for the Ark 564 absorber does not have the typical ''S'' shape, even if the metallicity is super-solar; as a result, the two WA phases do not appear to be in pressure balance. This suggests that the continuum incident on the absorbing gas is perhaps different from the observed continuum. We also estimated the mass outflow rate and the associated kinetic energy and find it to be at most 0.009% of the bolometric luminosity of Ark 564. Thus, it is highly unlikely that these outflows provide significant feedback required by the galaxy formation models.

  5. DETECTION OF HIGH VELOCITY OUTFLOWS IN THE SEYFERT 1 GALAXY Mrk 590

    SciTech Connect

    Gupta, A.; Mathur, S.; Krongold, Y.

    2015-01-01

    We report on the detection of ultra-fast outflows in the Seyfert 1 galaxy Mrk 590. These outflows are identified through highly blueshifted absorption lines of O VIII and Ne IX in the medium energy grating spectrum and Si XIV and Mg XII in the high energy grating spectrum on board the Chandra X-ray observatory. Our best-fit photoionization model requires two absorber components at outflow velocities of 0.176c and 0.0738c and a third tentative component at 0.0867c. The components at 0.0738c and 0.0867c have high ionization parameters and high column densities, similar to other ultra-fast outflows detected at low resolution by Tombesi et al. We also found suggestive evidence for super-solar silicon in these components. These outflows carry sufficient mass and energy to provide effective feedback proposed by theoretical models. The component at 0.176c, on the other hand, has a low ionization parameter and low column density, similar to those detected by Gupta et al. in Ark 564. These absorbers occupy a different locus on the velocity versus ionization parameter plane and have opened up a new parameter space of active galactic nucleus (AGN) outflows. The presence of ultra-fast outflows in moderate luminosity AGNs poses a challenge to models of AGN outflows.

  6. GAS OUTFLOWS IN SEYFERT GALAXIES: EFFECTS OF STAR FORMATION VERSUS AGN FEEDBACK

    SciTech Connect

    Melioli, C.; Pino, E. M. de Gouveia Dal E-mail: dalpino@iag.usp.br

    2015-10-20

    Large-scale, weakly collimated outflows are very common in galaxies with large infrared luminosities. In complex systems in particular, where intense star formation (SF) coexists with an active galactic nucleus (AGN), it is not clear yet from observations whether the SF, the AGN, or both are driving these outflows. Accreting supermassive black holes are expected to influence their host galaxies through kinetic and radiative feedback processes, but in a Seyfert galaxy, where the energy emitted in the nuclear region is comparable to that of the body of the galaxy, it is possible that stellar activity is also playing a key role in these processes. In order to achieve a better understanding of the mechanisms driving the gas evolution especially at the nuclear regions of these galaxies, we have performed high-resolution three-dimensional hydrodynamical simulations with radiative cooling considering the feedback from both SF regions, including supernova (Type I and II) explosions and an AGN jet emerging from the central region of the active spiral galaxy. We computed the gas mass lost by the system, separating the role of each of these injection energy sources on the galaxy evolution, and found that at scales within 1 kpc an outflow can be generally established considering intense nuclear SF only. The jet alone is unable to drive a massive gas outflow, although it can sporadically drag and accelerate clumps of the underlying outflow to very high velocities.

  7. A Low-mass Black Hole in the Nearby Seyfert Galaxy UGC 06728

    NASA Astrophysics Data System (ADS)

    Bentz, Misty C.; Batiste, Merida; Seals, James; Garcia, Karen; Kuzio de Naray, Rachel; Peters, Wesley; Anderson, Matthew D.; Jones, Jeremy; Lester, Kathryn; Machuca, Camilo; Parks, J. Robert; Pope, Crystal L.; Revalski, Mitchell; Roberts, Caroline A.; Saylor, Dicy; Sevrinsky, R. Andrew; Turner, Clay

    2016-11-01

    We present the results of a recent reverberation mapping campaign for UGC 06728, a nearby low-luminosity Seyfert 1 in a late-type galaxy. Nightly monitoring in the spring of 2015 allowed us to determine an Hβ time delay of τ =1.4+/- 0.8 days. Combined with the width of the variable Hβ line profile, we determine a black hole mass of {M}{BH}=(7.1+/- 4.0)× {10}5 {M}ȯ . We also constrain the bulge stellar velocity dispersion from higher-resolution long-slit spectroscopy along the galaxy minor axis and find {σ }\\star =51.6+/- 4.9 km s‑1. The measurements presented here are in good agreement with both the {R}{BLR}{--}L relationship and the {M}{BH}{--}{σ }\\star relationship for active galactic nuclei. Combined with a previously published spin measurement, our mass determination for UGC 06728 makes it the lowest-mass black hole that has been fully characterized, and thus an important object to help anchor the low-mass end of black hole evolutionary models.

  8. SBS 0846+513: a new γ-ray-emitting narrow-line Seyfert 1 galaxy

    NASA Astrophysics Data System (ADS)

    D'Ammando, F.; Orienti, M.; Finke, J.; Raiteri, C. M.; Angelakis, E.; Fuhrmann, L.; Giroletti, M.; Hovatta, T.; Max-Moerbeck, W.; Perkins, J. S.; Readhead, A. C. S.; Richards, J. L.; Stawarz, Ł.; Donato, D.

    2012-10-01

    We report Fermi Large Area Telescope (LAT) observations of the radio-loud active galactic nucleus SBS 0846+513 (z = 0.5835), optically classified as a narrow-line Seyfert 1 galaxy, together with new and archival radio-to-X-ray data. The source was not active at γ-ray energies during the first two years of Fermi operation. A significant increase in activity was observed during 2010 October-2011 August. In particular, a strong γ-ray flare was observed in 2011 June reaching an isotropic γ-ray luminosity (0.1-300 GeV) of 1.0 × 1048 erg s-1, comparable to that of the brightest flat spectrum radio quasars, and showing spectral evolution in γ rays. An apparent superluminal velocity of (8.2 ± 1.5)c in the jet was inferred from 2011 to 2012 Very Long Baseline Array (VLBA) images, suggesting the presence of a highly relativistic jet. Both the power released by this object during the flaring activity and the apparent superluminal velocity are strong indications of the presence of a relativistic jet as powerful as those of blazars. In addition, variability and spectral properties in radio and γ-ray bands indicate blazar-like behaviour, suggesting that, except for some distinct optical characteristics, SBS 0846+513 could be considered as a young blazar at the low end of the blazar's black hole mass distribution.

  9. Photometric activity of the Seyfert galaxy Markarian 6 from UBV observations in 1970-2001

    NASA Astrophysics Data System (ADS)

    Doroshenko, V. T.

    2003-07-01

    The light curve of Mrk 6 for 1970-2002 is presented and discussed. The amplitudes of variability were 1.6m, 1.1m, and 0.8m in UBV bands, respectively. The magnitudes of the underlying galaxy in the 27.5'' aperture were found to be Ug=15.82, Bg=15.42 and Vg=14.36. The mean color indices of the variable component are (U-B)var=-0.49 and (B-V)var=0.75 without correction for reddening. In the time intervals from 10 days to 1300 days the structure function can be presented as a power function, S F~tau b, where b=0.72+/-0.04. The time where the SF for Mrk 6 reaches the upper plateau is about 3300 days. The observed SF can be interpreted by the superposition of independent flares model with the maximal duration of flares ~ 800 days. If these flares are located in the radiation pressure dominated region of the accretion disk, the size of this region is about 70, 330 RS, assuming the viscous parameter alpha is 0.1, 0.01, respectively. It is concluded that the optical long-term variability of Seyfert galaxies can be explained by thermal instability in the accretion disk.

  10. Hot gas in the center of the Seyfert galaxy NGC 3079

    NASA Astrophysics Data System (ADS)

    Miyamoto, Yusuke; Nakai, Naomasa; Seta, Masumichi; Salak, Dragan; Nagai, Makoto; Ishii, Shun; Yamauchi, Aya

    2015-08-01

    The nearby (d = 19.7 Mpc) Seyfert galaxy NGC 3079 exhibits a prominent bubble emerging from the nucleus. In order to investigate the nuclear power source, we carried out ammonia observations toward the center of NGC 3079 with the Tsukuba 32-m telescope and the JVLA. The NH3 (J, K) = (1, 1) through (6,6) lines were detected in absorption at the center of NGC 3079 with the JVLA, although the profile of NH3(3,3) was in emission in contrast to the other transitions. All ammonia absorption lines have two distinct velocity components: one is at the systemic velocity (Vsys ~ 1116 km s-1) and the other is blueshifted (Vsys ~ 1020 km s-1), and both components are aligned along the nuclear jets. The blueshifted NH3(3,3) emission can be regarded as ammonia masers associated with shocks by strong winds probably from newly formed massive stars or supernova explosions in the nuclear megamaser disk. The derived rotational temperature, Trot = 120±12 K for the systemic component and Trot = 157±19 K for the blueshifted component, and fractional abundance of NH3 relative to molecular hydrogen H2 are higher than those in other galaxies reported. The high temperature environment at the center may be mainly attributed to heating by the nuclear jets.

  11. Rapid Compton-thick/Compton-thin Transitions in the Seyfert 2 Galaxy NGC 1365

    NASA Technical Reports Server (NTRS)

    Risaliti, G.; Elvis, M.; Fabbiano, G.; Baldi, A.; Zezas, A.

    2006-01-01

    We present multiple Chandra and XMM-Newton observations of the type 1.8 Seyfert galaxy NGC 1365, which shows the most dramatic X-ray spectral changes observed so far in an active galactic nucleus: the source switched from reflection-dominated to transmission-dominated and back in just 6 weeks. During this time the soft thermal component, arising from a approx. 1 kpc region around the center, remained constant. The reflection component is constant at all timescales, and its high flux relative to the primary component implies the presence of thick gas covering a large fraction of the solid angle. The presence of this gas, and the fast variability timescale, suggest that the Compton-thick to Compton-thin change is due to variation in the line-of-sight absorber rather than to extreme intrinsic emission variability. We discuss a structure of the circumuclear absorber/reflector that can explain the observed X-ray spectral and temporal properties.

  12. Ionized gas kinematics within the inner kiloparsec of the Seyfert galaxy NGC 1365

    NASA Astrophysics Data System (ADS)

    Lena, Davide; Robinson, Andrew; Storchi-Bergmann, Thaisa; Couto, Guilherme S.; Schnorr-Müller, Allan; Riffel, Rogemar A.

    2016-07-01

    We observed the nuclear region of the galaxy NGC 1365 with the integral field unit of the Gemini Multi Object Spectrograph mounted on the GEMINI-South telescope. The field of view covers 13 × 6 arcsec2(1173 × 541 pc2) centred on the nucleus, at a spatial resolution of 52 pc. The spectral coverage extends from 5600 to 7000 Å, at a spectral resolution R = 1918. NGC 1365 hosts a Seyfert 1.8 nucleus, and exhibits a prominent bar extending out to 100 arcsec (9 kpc) from the nucleus. The field of view lies within the inner Lindblad resonance. Within this region, we found that the kinematics of the ionized gas (as traced by [O I], [N II], Hα, and [S II]) is consistent with rotation in the large-scale plane of the galaxy. While rotation dominates the kinematics, there is also evidence for a fan-shaped outflow, as found in other studies based on the [O III] emission lines. Although evidence for gas inflowing along nuclear spirals has been found in a few barred galaxies, we find no obvious signs of such features in the inner kiloparsec of NGC 1365. However, the emission lines exhibit a puzzling asymmetry that could originate from gas which is slower than the gas responsible for the bulk of the narrow-line emission. We speculate that it could be tracing gas which lost angular momentum, and is slowly migrating from the inner Lindblad resonance towards the nucleus of the galaxy.

  13. NGC 4051 and the Nature of Narrow-Line Seyfert I Galaxies

    NASA Technical Reports Server (NTRS)

    Peterson, B. M.; McHardy, I. M.; Wilkes, B. J.

    2004-01-01

    We report on the results of a three-year program of coordinated X-ray and optical monitoring of the narrow-line Seyfert 1 galaxy NGC 4051. The principal results of this program are: (1) The H-beta emission line time lag and Doppler width yield a virial mass estimate of about 1.1 mission solar masses, at the extreme low end of AGN masses. A plausible adjustment for inclination effects increases this mass slightly to about 1.4 mission solar masses. (2) During the third year of this campaign, both the X-ray continuum and the He II 4686 line went into extremely low states, although the optical continuum and the H-beta broad line were both still present and variable. We suggest that the inner part of the accretion disk may have gone into an advection-dominated state, yielding little radiation from the hotter inner disk. (3) The He II 4686 line is almost five times as broad as H-beta, and it is strongly blueward asymmetric, as are the high-ionization UV lines recorded in archive spectra of NGC 4051. The data are consistent with the Balmer lines arising in a low-inclination disk-like configuration, and the high-ionization lines arising in an outflowing wind, of which we observe preferentially the near side.

  14. Discovery of a fast transient outflow in the Seyfert 1 galaxy NGC 985

    NASA Astrophysics Data System (ADS)

    Ebrero, J.; Kriss, J.; Kaastra, J.; Domcek, V.

    2016-06-01

    Obscuration events in active galaxies are key to understand the physical conditions and the dynamics of the gas in the vicinity of their central super-massive black hole. Using recent joint observations with XMM-Newton and the Hubble Space Telescope of the nearby Seyfert 1 galaxy NGC 985, we have monitored the pass-by of obscuring material across our line of sight, traveling at 6000 km/s. This kind of event has been recorded previously in only a handful of cases. The properties of this transient absorber suggest that it may originate very close to the broad line region, possibly in an accretion disk wind. Moreover, by analyzing past archival observations of NGC 985, we found evidence that this obscuration process is recurrent. The analysis of the RGS spectra of this source at different epochs reveals that some of the components of the persistent warm absorber vary in response to the changes in the ionizing flux caused by this transient obscurer. In this way, we are able to derive stringent upper limits on the location of the warm absorber.

  15. An XMM-Newton Study of the Bright Narrow-Line Seyfert 1 Galaxy Arakelian 564

    NASA Technical Reports Server (NTRS)

    Brandt, Niel

    2004-01-01

    We report on two XMM-Newton observations of the bright Narrow-Line Seyfert 1 galaxy Ark 564 taken one year apart (2000 June and 2001 June). The 0.6-10 keV continuum is well described by a soft blackbody component (kT - 140-150 eV) plus a steep power law (Gamma - 2.50-2.55). No significant spectral changes are observed between the two observations, although the X-ray flux in the second observation is - 40-50 per cent lower. In both observations we detect a significant absorption edge at a rest-frame energy of - 0.73 keV, corresponding to 0 VII. The presence of the absorption feature is confirmed by a simultaneous Chandra grating observation in 2000 June, although the best-fitting edge threshold is at a slightly lower energy in the Chandra data, possibly because of a different parameterization of the underlying X-ray continuum. We find tentative evidence for a broad iron emission line in the 2000 June observation. The results from an analysis of the power spectral density (PSD) function are also presented. The present XMM-Newton data support the idea that the PSD shows two breaks, although the location of the high-frequency break requires further constraints.

  16. SBS 0846+513: a New Gamma-ray Emitting Narrow-line Seyfert 1 Galaxy

    NASA Technical Reports Server (NTRS)

    D'Ammando, F.; Orienti, M.; Finke, J.; Raiteri, C. M.; Angelakis, E.; Fuhrmann, L.; Giroletti, M.; Hovatta, T.; Max-Moerbeck, W.; Perkins, J. S.; Readhead, A. C. S.; Richards, J. L.; Stawarz, L.; Donato, D.

    2012-01-01

    We report Fermi-LAT observations of the radio-loud AGN SBS 0846+513 (z=0.5835), optically classified as a Narrow-Line Seyfert 1 galaxy, together with new and archival radio-to-X-ray data. The source was not active at ?-ray energies during the first two years of Fermi operation. A significant increase in activity was observed during 2010 October-2011 August. In particular a strong gamma-ray flare was observed in 2011 June reaching an isotropic ?-ray luminosity (0.1-300 GeV) of 1.0×10(sup 48) erg s(sup -1), comparable to that of the brightest flat spectrum radio quasars, and showing spectral evolution in gamma rays. An apparent superluminal velocity of (8.2+/-1.5)c in the jet was inferred from 2011-2012 VLBA images, suggesting the presence of a highly relativistic jet. Both the power released by this object during the flaring activity and the apparent superluminal velocity are strong indications of the presence of a relativistic jet as powerful as those of blazars. In addition, variability and spectral properties in radio and gamma-ray bands indicate blazar-like behaviour, suggesting that, except for some distinct optical characteristics, SBS 0846+513 could be considered as a young blazar at the low end of the blazar's black hole mass distribution.

  17. UBVRI Light Curves of the Seyfert Galaxy NGC 7469 During 1990-1998: Microvariability

    NASA Astrophysics Data System (ADS)

    Merkulova, N. I.

    2000-02-01

    Observations of the nuclear region of the Seyfert galaxy NGC 7469 obtained at Crimean Astrophysical Observatory with the 1.25 m telescope are presented. During 64 nights on nine observational runs between 1990 September 24 and 1998 October 22 in each spectral band of the Johnson UBVRI system, about 1500 measurements have been performed simultaneously through the round aperture 20" in diameter using differential photometry techniques. The estimated accuracy of each measurement is about 0.01 mag. During the observing period 1990-1996 the mean luminosity of the nucleus was almost constant; only overlapping brightness fluctuations were observed. The mean luminosity level has been raised in 1996 October. The peak amplitude (maximum flux/minimum flux) Fmax/Fmin=2.09 on the light curves was observed in the U band, while the minimum amplitude Fmax/Fmin=1.32 was in the I band for the entire observation period. Using structure function (SF) analysis, the following conclusions have been made: (1) Long-term variability is caused by the same processes in the optical, because the slope b of the SF is approximately equal for all wave bands, except for the I band the slope is appreciably distinguished from the others. This would be an indication of the presence of an independent IR energy source in NGC 7469. (2) Considering the same time interval (from 6 minutes to 2 hr) for intranight variability on SFs at different wave bands, one can conclude that flicker noise causes variations observed on the light curve at the UV region (U and B bands), while at the near-IR region the light curve is formed by mixed shot noise and flicker noise-the greater the wavelength, the more the contribution of shot noise processes. (3) On intranight light curves of the NGC 7469 there exist rapid flares with durations ~25 minutes at U band, ~55 minutes at B, V bands, and ~2 hr at R, I bands-a typical timescale of intranight variability increasing with the increasing wavelength. In order to examine the

  18. THE GEOMETRY OF MASS OUTFLOWS AND FUELING FLOWS IN THE SEYFERT 2 GALAXY MRK 3

    SciTech Connect

    Crenshaw, D. M.; Fischer, T. C.; Kraemer, S. B.; Schmitt, H. R.; Jaffe, Y. L.; Deo, R. P.; Collins, N. R.

    2010-03-15

    We present a study of the resolved emission-line regions and an inner dust/gas disk in the Seyfert 2 galaxy Mrk 3, based on Hubble Space Telescope observations. We show that the extended narrow-line region (ENLR), spanning {approx}4 kpc, is defined by the intersection of the ionizing bicone of radiation from the active galactic nucleus (AGN) and the inner disk, which is not coplanar with the large-scale stellar disk. This intersection leads to different position and opening angles of the ENLR compared to the narrow-line region (NLR). A number of emission-line arcs in the ENLR appear to be continuations of dust lanes in the disk, supporting this geometry. The NLR, which consists of outflowing emission-line knots spanning the central {approx}650 pc, is in the shape of a backward S. This shape may arise from rotation of the gas, or it may trace the original fueling flow close to the nucleus that was ionized after the AGN turned on.

  19. Soft X-ray spectral observations of quasars and high X-ray luminosity Seyfert galaxies

    NASA Technical Reports Server (NTRS)

    Petre, R.; Mushotzky, R. F.; Krolik, J. H.; Holt, S. S.

    1983-01-01

    Results of the analysis of 28 Einstein SSS observations of 15 high X-ray luminosity (L(x) 10 to the 435 power erg/s) quasars and Seyfert type 1 nuclei are presented. The 0.75-4.5 keV spectra are in general well fit by a simple model consisting of a power law plus absorption by cold gas. The averager spectral index alpha is 0.66 + or - .36, consistent with alpha for the spectrum of these objects above 2 keV. In all but one case, no evidence was found for intrinsic absorption, with an upper limit of 2 x 10 to the 21st power/sq cm. Neither was evidence found for partial covering of the active nucleus by dense, cold matter (N(H) 10 to the 22nd power/sq cm; the average upper limit on the partial covering fraction is 0.5. There is no obvious correlation between spectral index and 0175-4.5 keV X-ray luminosity (which ranges from 3 x 10 to the 43rd to 47th powers erg/s or with other source properties. The lack of intrinsic X-ray absorption allows us to place constraints on the density and temperature of the broad-line emission region, and narrow line emission region, and the intergalactic medium.

  20. Decoding the spectral variations in the bare Seyfert 1 galaxy Fairall 9

    NASA Astrophysics Data System (ADS)

    Lohfink, Anne; Reynolds, Christopher S.; Alston, William; Pinto, Ciro

    2016-04-01

    X-ray spectroscopy and variability are powerful tools to understand the fundamental physics and accretion processes occurring in active galactic nuclei. The analysis is often hampered by the wealth of processes occurring simultaneously, making them difficult to disentangle. Our talk focuses on the luminous Seyfert 1 galaxy Fairall 9, whose spectrum and timing behavior is much simpler, as it is not affected by absorption processes. We aim to present a comprehensive spectral and timing study, based on an observing campaign performed in 2014. It consisted of a long-term Swift monitoring, three pointed XMM observations and one NUSTAR observation, performed jointly with one of XMM pointings. The different flux states of the pointed XMM observations allow us to identify the continuum as the main variability driver and constrain the accretion disk parameters with unprecedented quality. We are also able to establish that the source geometry remained absolutely unchanged over several months, a behavior not seen in other AGN. We study the connection of the UV and X-ray emission from the long-term Swift monitoring and establish that the UV lags the X-rays by several days. These time lags are then compared, together with the UV rms spectrum, to what is expected for a standard thin accretion disk and put into context of the results from the analysis of the XMM and NuSTAR data. Taken together this will provide us with the most complete picture of this AGN yet.

  1. Eye in the Sky: A New Look at the Seyfert Connection

    NASA Technical Reports Server (NTRS)

    Helfand, David J.

    1997-01-01

    Observations obtained under this ASCA grant have been fully reduced. We have also extracted data from the ROSAT archive to complement the ASCA spectrum, and demonstrate that the source is time variable, a key clue to its nature. These results are nearly ready for submission. To reconcile the high soft X-ray luminosity of IRAS 00317-2142 with its properties at other wavelengths, we observed the galaxy with the ASCA satellite on 12/12/95 for 37 ks with these SIS and 41 ks with the GIS; a fit to the combined spectra. In combination with an archived 9.3 ks ROSAT PSPC observation, obtained 6/23/92 these data reveal significant spectral and flux variability. Although somewhat prosaic, these results are very significant in the context of the so called 'narrow-line X-ray galaxies' which are being discovered with increasing frequency in surveys of faint ROSAT sources. It may well be that these too are unremarkable and are included in current counts of Seyfert galaxies, meaning they are not the long-sought new component of the cosmic X-ray background.

  2. KEPLER OBSERVATIONS OF THE SEYFERT 1 GALAXY II ZW 229.015

    SciTech Connect

    Carini, M. T.; Ryle, Wesley T.

    2012-04-10

    The Seyfert 1 galaxy II ZW 229.015 has been observed with the Kepler spacecraft since quarter 4 of Kepler science operations. The results of the quarters 4-7 (1 year) Kepler observations are presented in this paper. We find the source to be highly variable on multiple timescales, with discrete variations occurring on timescales as short as tens of hours with amplitudes as small as 0.5%. Such small amplitude, rapid variability has never before been detected in active galactic nuclei. The presence of a strong galaxy component dilutes the variability determined from the photometric aperture used in the standard Kepler PDC analysis. Using the tools provided by the Kepler Guest Observer Office and simultaneous V-band photometry found in the literature, we determine an optimal customized aperture for photometry of this source with Kepler. The results of a PSRESP analysis reveal tentative evidence of a characteristic variability timescale in the power spectrum. Using this timescale, we estimate the mass of the central supermassive black hole and this estimate is consistent with the virial mass estimate from reverberation mapping studies.

  3. Deconvolving X-ray spectral variability components in the Seyfert 1.5 NGC 3227

    SciTech Connect

    Arévalo, P.; Markowitz, A.

    2014-03-10

    We present the variability analysis of a 100 ks XMM-Newton observation of the Seyfert 1.5 active galaxy, NGC 3227. The observation found NGC 3227 in a period where its hard power-law component displayed remarkably little long-term variability. This lucky event allows us to clearly observe a soft spectral component undergoing a large-amplitude but slow flux variation. Using combined spectral and timing analysis, we isolate two independent variable continuum components and characterize their behavior as a function of timescale. Rapid and coherent variations throughout the 0.2-10 keV band reveal a spectrally hard (photon index Γ ∼ 1.7-1.8) power law, dominating the observed variability on timescales of 30 ks and shorter. Another component produces coherent fluctuations in the 0.2-2 keV range and is much softer (Γ ∼ 3); it dominates the observed variability on timescales greater than 30 ks. Both components are viewed through the same absorbers identified in the time-averaged spectrum. The combined spectral and timing analysis breaks the degeneracy between models for the soft excess: it is consistent with a power-law or thermal Comptonized component but not with a blackbody or an ionized reflection component. We demonstrate that the rapid variability in NGC 3227 is intrinsic to continuum-emitting components and is not an effect of variable absorption.

  4. A DISTINCTIVE DISK-JET COUPLING IN THE LOWEST-MASS SEYFERT, NGC 4395

    SciTech Connect

    King, Ashley L.; Miller, Jon M.; Reynolds, Mark T.; Gueltekin, Kayhan; Gallo, Elena; Maitra, Dipankar

    2013-09-10

    Simultaneous observations of X-rays and radio luminosities have been well studied in accreting stellar-mass black holes. These observations are performed in order to understand how mass accretion rates and jetted outflows are linked in these individual systems. Such contemporaneous studies in supermassive black holes (SMBH) are harder to perform, as viscous times scale linearly with mass. However, as NGC 4395 is the lowest known mass Seyfert galaxy, we have used it to examine the simultaneous X-ray (Swift) and radio (Very Large Array) correlation in a SMBH in a reasonably timed observing campaign. We find that the intrinsic X-ray variability is stronger than the radio variability, and that the fluxes are only weakly or tentatively coupled, similar to prior results obtained in NGC 4051. If the corona and the base of the jet are one and the same, this may suggest that the corona in radio-quiet active galactic nucleus filters disk variations, only transferring the strongest and/or most sustained variations into the jet. Further, when both NGC 4395 and NGC 4051 are placed on the stellar-mass L{sub X} -L{sub R} plane, they appear to reside on the steeper L{sub X} -L{sub R} track. This suggests that SMBHs also follow two distinct tracks just as stellar-mass black holes do, and supports the idea that the same physical disk-jet mechanisms are at play across the mass scale.

  5. The Spectral Energy Distribution of the Seyfert Galaxy Ton S180

    NASA Technical Reports Server (NTRS)

    Turner, T. J.; Romano, P.; Kraemer, S. B.; George, I. M.; Yaqoob, T.; Crenshaw, D. M.; Storm, J.; Alloin, D.; Lazzaro, D.; DaSilva, L.; White, Nicholas E. (Technical Monitor)

    2001-01-01

    We present spectral results from a multi-satellite, broad-band campaign on the Narrow-line Seyfert 1 galaxy Ton S180 performed at the end of 1999. We discuss the spectral-energy distribution of the source, combining simultaneous Chandra, ASCA and EUVE data with contemporaneous FUSE, HST, and ground-based optical and infrared data. The resulting SED shows that most of the, energy is emitted in the 10 - 100 eV regime, which must be dominated by the primary energy source. No spectral turnover is evident in the UV regime. This, the strong soft X-ray emission, and the overall shape of the SED indicate that emission from the accretion disk peaks between 15 and 100 eV. High resolution FUSE spectra showing UV absorption due to OVI and the lack of detectable X-ray absorption in the Candra spectrum demonstrate the presence of a low column density of highly ionized gas along our line of sight.

  6. Narrow-Line Seyfert 1 Galaxies and their place in the Universe

    NASA Astrophysics Data System (ADS)

    Foschini, L.; Colpi, M.; Gallo, L.; Grupe, D.; Komossa, S.; Leighly, K.; Mathur, S.

    In 1978, Davidson and Kinman wrote about Markarian 359: "This unusual object merits further observations...". In 1985, Osterbrock and Pogge defined a new class of active galactic nuclei (AGN), named Narrow-Line Seyfert 1 (NLS1). Twenty-five years later, NLS1s still continue to intrigue and bewilder. NLS1s manifest extreme behaviour at all wavelengths. They exhibit the most extreme X-ray variability seen in radio-quiet AGN, the most intense optical FeII emission, and high rates of star formation. In general, their characteristics are consistent of AGNs with relatively low mass black holes accreting close to the Eddington rate. The 2009 Fermi Gamma-ray Space Telescope discovery of high-energy (E>100 MeV) gamma rays in a handful of NLS1s has established the existence of relativistic jets in these systems -- a fact previously hinted at by the flat radio spectrum and high brightness temperature seen in some objects. Since NLS1 are generally hosted by spirals, this poses some intriguing questions on the galaxy evolution and on how relativistic jets are generated. It is therefore time for the broad community to come together and discuss what we have discovered in the last quarter century and lay the foundation for future work. Workshop Topics: * Central engine: BH mass, accretion disk, BLR/NLR, jet * Host galaxy: morphology, star formation, merging history * NLS1 in the Universe: comparison with other types of AGN, surveys/statistics, formation/merging, cosmological evolution

  7. High-Resolution X-Ray Spectroscopy of the Seyfert 2 Galaxy Circinus with Chandra

    NASA Technical Reports Server (NTRS)

    Sambruna, Rita M.; Netzer, Hagai; Kaspi, Shai; Brandt, W. N.; Chartas, G.; Garmire, G. P.; Nousek, John A.; Weaver, K. A.

    2000-01-01

    Results from a 60 ks Chandra High Energy Transmission Grating Spectrometer (HETGS) observation of the nearby Seyfert 2 Circinus are presented. The spectrum shows a wealth of emission lines at both soft and hard X-rays, including lines of Ne, Mg, Si, S, Ar, Ca, and Fe, and a prominent Fe K(alpha) line at 6.4 keV. We identify several of the He-like components and measure several of the Lyman lines of the N-like ions. The lines' profiles are unresolved at the limited signal-to-noise ratio of the data. Our analysis of the zeroth-order image in a companion paper constrains the size of the emission region to be 20-60 pc, suggesting that emission within this volume is almost entirely due to the reprocessing of the obscured central source. Here we show that a model containing two distinct components can reproduce almost all the observed properties of this gas. The ionized component can explain the observed intensities of the ionized species, assuming twice-solar composition and an N is proportional r(exp -1.5) density distribution. The neutral component is highly concentrated, well within the 0.8" point source, and is responsible for almost all of the observed K(alpha) (6.4 keV) emission. Circinus seems to be different than Mkn 3 in terms of its gas distribution.

  8. 3D spectroscopy of merger Seyfert galaxy Mrk 334: nuclear starburst, superwind and the circumnuclear cavern

    NASA Astrophysics Data System (ADS)

    Smirnova, Aleksandrina; Moiseev, Alexei

    2010-01-01

    We are presenting new results on kinematics and structure of the Mrk 334 Seyfert galaxy. Panoramic (3D) spectroscopy is performed at the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences using the integral-field Multi-Pupil Fiber Spectrograph (MPFS) and scanning Fabry-Pérot interferometer. The deep images have revealed that Mrk 334 is observed during the final stage of its merging with a massive companion. A possible mass ratio ranges from 1/5 to 1/3. The merger has triggered mass redistribution in the disc resulting in an intensification of nuclear activity and in a burst of star formation in the inner region of the galaxy. The circumnuclear starburst is so intense that its contribution to the gas ionization exceeds that contribution of the active galactic nuclei (AGN). We interpret the nuclear gas outflow with velocities of ~200kms-1 as a galactic superwind that accompanies the violent star formation. This suggestion is consistent with the asymmetric X-ray brightness distribution in Mrk 334. The trajectory of the fragments of the disrupted satellite in the vicinity of the main galaxy nucleus can be traced. In the galaxy disc, a cavern is found that is filled with a low-density ionized gas. We consider this region to be the place where the remnants of the companion have recently penetrated through the gaseous disc of the main galaxy.

  9. UV and X-ray variability of the narrow-line Seyfert 1 galaxy Ark 564

    NASA Astrophysics Data System (ADS)

    Ezhikode, Savithri H.; Dewangan, Gulab C.; Misra, Ranjeev; Tripathi, Shruti; Sajeeth Philip, Ninan; Kembhavi, Ajit K.

    2016-07-01

    We analyze eight XMM-Newton observations of the bright Narrow Line Seyfert 1 galaxy Arakelian 564 (Ark 564). These observations, separated by ∼ 6 days, allow us to look for correlations between the simultaneous ultraviolet (UV) emission (from the Optical Monitor) with not only the X-ray flux but also with different X-ray spectral parameters. The X-ray spectra from all the observations are found to be adequately fitted by a double Comptonization model where the soft excess and the hard X-ray power law are represented by thermal Comptonization in a low temperature plasma and hot corona, respectively. Apart from the fluxes of each component, the hard X-ray power law index is found to be variable. These results suggest that the variability is associated with changes in the geometry of the inner region. The UV emission is found to be variable and well correlated with the high energy index while the correlations with the fluxes of each component are found to be weaker. Using viscous timescale arguments we rule out the possibility that the UV variation is due to the fluctuating accretion rate in the outer disk. If the UV variation is driven by X-ray reprocessing, then our results indicate that the strength of the X-ray reprocessing depends more on the geometry of the X-ray producing inner region rather than on the X-ray luminosity alone.

  10. OUTFLOWS FROM ACTIVE GALACTIC NUCLEI: KINEMATICS OF THE NARROW-LINE AND CORONAL-LINE REGIONS IN SEYFERT GALAXIES

    SciTech Connect

    Mueller-Sanchez, F.; Prieto, M. A.; Vives-Arias, H.; Davies, R. I.; Tacconi, L. J.; Genzel, R.; Malkan, M.

    2011-10-01

    As part of an extensive study of the physical properties of active galactic nuclei (AGNs) we report high spatial resolution near-IR integral-field spectroscopy of the narrow-line region (NLR) and coronal-line region (CLR) of seven Seyfert galaxies. These measurements elucidate for the first time the two-dimensional spatial distribution and kinematics of the recombination line Br{gamma} and high-ionization lines [Si VI], [Al IX], and [Ca VIII] on scales <300 pc from the AGN. The observations reveal kinematic signatures of rotation and outflow in the NLR and CLR. The spatially resolved kinematics can be modeled as a combination of an outflow bicone and a rotating disk coincident with the molecular gas. High-excitation emission is seen in both components, suggesting it is leaking out of a clumpy torus. While NGC 1068 (Seyfert 2) is viewed nearly edge-on, intermediate-type Seyferts are viewed at intermediate angles, consistent with unified schemes. A correlation between the outflow velocity and the molecular gas mass in r < 30 pc indicates that the accumulation of gas around the AGN increases the collimation and velocity of the outflow. The outflow rate is 2-3 orders of magnitude greater than the accretion rate, implying that the outflow is mass loaded by the surrounding interstellar medium (ISM). In half of the observed AGNs, the kinetic power of the outflow is of the order of the power required by two-stage feedback models to be thermally coupled to the ISM and to match the M{sub BH}-{sigma}* relation. In these objects, the radio jet is clearly interacting with the ISM, indicative of a link between jet power and outflow power.

  11. The Penrose photoproduction scenario for NGC 4151: A black hole gamma-ray emission mechanism for active galactic nuclei and Seyfert galaxies. [Compton scattering and pair production

    NASA Technical Reports Server (NTRS)

    Leiter, D.

    1979-01-01

    A consistent theoretical interpretation is given for the suggestion that a steepening of the spectrum between X-ray and gamma ray energies may be a general, gamma-ray characteristic of Seyfert galaxies, if the diffuse gamma ray spectrum is considered to be a superposition of unresolved contributions, from one or more classes of extragalactic objects. In the case of NGC 4151, the dominant process is shown to be Penrose Compton scattering in the ergosphere of a Kerr black hole, assumed to exist in the Seyfert's active galactic nucleus.

  12. HST observations of NGC 4395, the least luminous Seyfert 1 nucleus - Evidence against the starburst hypothesis for broad-lined active galactic nuclei

    NASA Technical Reports Server (NTRS)

    Filippenko, Alexei V.; Ho, Luis C.; Sargent, Wallace L. W.

    1993-01-01

    The starburst hypothesis for broad-line AGN is examined here using ultraviolet spectra and optical images of NGC 4395, the least luminous Seyfert 1 nucleus. From the evidence it is concluded that the apparent activity in the Seyfert 1 nucleus of NGC 4395 probably cannot be explained in the context of the starburst hypothesis of Terlevich et al. (1992). The strongest piece of evidence is the absence of stellar absorption lines, especially in the UV and NIR spectra. Other relevant characteristics are the UV spectral index of roughly -1, small physical size, low luminosity, and lack of obvious variability.

  13. Does the inner broad-line region dim down when the power turns up?. [Seyfert 1 galaxy NGC 5548

    NASA Technical Reports Server (NTRS)

    Sparke, Linda S.

    1993-01-01

    The temporal correlations of continuum and broad emission-line fluxes from the Seyfert galaxy NGC 5548 as measured during the 1989 monitoring campaign show two related peculiarities: first, some of the crosscorrelations of line and continuum flux appear steeper on the negative time lag side than the continuum autocorrelation itself; then, the autocorrelation of the line flux is sometimes more sharply peaked than the continuum autocorrelation function. These are here interpreted as evidence that conditions in the inner part of the broad-line region are such that some emission lines decrease in intensity as the continuum strengthens.

  14. Radio-Loud Narrow-Line Seyfert 1 as a New Class of Gamma-Ray Active Galactic Nuclei

    NASA Astrophysics Data System (ADS)

    Abdo, A. A.; Ackermann, M.; Ajello, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Burnett, T. H.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Casandjian, J. M.; Cecchi, C.; Çelik, Ö.; Chekhtman, A.; Cheung, C. C.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Conrad, J.; Cutini, S.; Dermer, C. D.; de Palma, F.; Silva, E. do Couto e.; Drell, P. S.; Dubois, R.; Dumora, D.; Farnier, C.; Favuzzi, C.; Fegan, S. J.; Focke, W. B.; Foschini, L.; Frailis, M.; Fukazawa, Y.; Fusco, P.; Gargano, F.; Gehrels, N.; Germani, S.; Giebels, B.; Giglietto, N.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Grove, J. E.; Guillemot, L.; Guiriec, S.; Hayashida, M.; Hays, E.; Horan, D.; Hughes, R. E.; Jóhannesson, G.; Johnson, A. S.; Johnson, W. N.; Kadler, M.; Kamae, T.; Katagiri, H.; Kataoka, J.; Kerr, M.; Knödlseder, J.; Kuss, M.; Lande, J.; Latronico, L.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Makeev, A.; Mazziotta, M. N.; McConville, W.; McEnery, J. E.; Meurer, C.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nolan, P. L.; Norris, J. P.; Nuss, E.; Ohsugi, T.; Omodei, N.; Orlando, E.; Ormes, J. F.; Pelassa, V.; Pepe, M.; Persic, M.; Pesce-Rollins, M.; Piron, F.; Porter, T. A.; Rainò, S.; Rando, R.; Razzano, M.; Rochester, L. S.; Rodriguez, A. Y.; Ryde, F.; Sadrozinski, H. F.-W.; Sambruna, R.; Sander, A.; Saz Parkinson, P. M.; Scargle, J. D.; Sgrò, C.; Smith, P. D.; Spandre, G.; Spinelli, P.; Strickman, M. S.; Suson, D. J.; Tagliaferri, G.; Takahashi, H.; Takahashi, T.; Tanaka, T.; Thayer, J. B.; Thayer, J. G.; Thompson, D. J.; Tibaldo, L.; Tibolla, O.; Torres, D. F.; Tosti, G.; Tramacere, A.; Uchiyama, Y.; Usher, T. L.; Vasileiou, V.; Vilchez, N.; Vitale, V.; Waite, A. P.; Wang, P.; Winer, B. L.; Wood, K. S.; Ylinen, T.; Ziegler, M.; Fermi/LAT Collaboration; Ghisellini, G.; Maraschi, L.; Tavecchio, F.

    2009-12-01

    We report the discovery with Fermi/LAT of γ-ray emission from three radio-loud narrow-line Seyfert 1 galaxies: PKS 1502+036 (z = 0.409), 1H 0323+342 (z = 0.061), and PKS 2004 - 447 (z = 0.24). In addition to PMN J0948+0022 (z = 0.585), the first source of this type to be detected in γ rays, they may form an emerging new class of γ-ray active galactic nuclei (AGNs). These findings can have strong implications on our knowledge about relativistic jets and the unified model of the AGN.

  15. The fast molecular outflow in the Seyfert galaxy IC 5063 as seen by ALMA

    NASA Astrophysics Data System (ADS)

    Morganti, Raffaella; Oosterloo, Tom; Oonk, J. B. Raymond; Frieswijk, Wilfred; Tadhunter, Clive

    2015-08-01

    We use high-resolution (0.5 arcsec) CO(2-1) observations performed with the Atacama Large Millimetre/submillimetre Array to trace the kinematics of the molecular gas in the Seyfert 2 galaxy IC 5063. The data reveal that the kinematics of the gas is very complex. A fast outflow of molecular gas extends along the entire radio jet (~1 kpc), with the highest outflow velocities about 0.5 kpc from the nucleus, at the location of the brighter hot spot in the western lobe. The ALMA data show that a massive, fast outflow with velocities up to 650kms-1 of cold molecular gas is present, in addition to the outflow detected earlier in warm H2, H i and ionized gas. All phases of the gas outflow show similar kinematics. IC 5063 appears to be one of the best examples of the multi-phase nature of AGN-driven outflows. Both the central AGN and the radio jet could energetically drive the outflow, however, the characteristics of the outflowing gas point to the radio jet being the main driver. This is an important result because IC 5063, although one of the most powerful Seyfert galaxies, is a relatively weak radio source (P1.4 GHz = 3 × 1023 W Hz-1). All the observed characteristics can be described by a scenario of a radio plasma jet expanding into a clumpy medium, interacting directly with the clouds and inflating a cocoon that drives a lateral outflow into the interstellar medium. This model is consistent with results obtained by recent simulations. A stronger, direct interaction between the jet and a gas cloud is present at the location of the brighter western lobe. This interaction may also be responsible for the asymmetry in the radio brightness of the two lobes. Even assuming the most conservative values for the conversion factor CO-to-H2, we find that the mass of the outflowing gas is between 1.9 and 4.8 × 107 M⊙, of which between 0.5 and 1.3 × 107 M⊙ is associated with the fast outflow at the location of the western lobe. These amounts are much larger than those of the

  16. Radio-to-Gamma-Ray Monitoring of the Narrow-line Seyfert 1 Galaxy PMN J0948+0022 from 2008 to 2011

    NASA Technical Reports Server (NTRS)

    Foschini, L.; Angelakis, E.; Fuhrmann, L.; Ghisellini, G.; Hovatta, T.; Lahteenmaki, A.; Lister, M. L.; Braito, V.; Gallo, L.; Hamilton, T. S.; Kino, M.; Komossa S.; Pushkarev, A. B.; Thompson, D. J.; Tibolla, O.; Tramacere, A.; Carrasco, L.; Carraminana, A.; Falcone, A.; Giroletti, M.; Grupe, D.; Kovalev, Y. Y.; Krichbaum, T. P.; Max-Moerbeck, W.; Nestoras, I.; Pearson, T.J.; Porras, A.; Readhead, A.C.S.; Recillas, E.; Richards, J.L.; Riquelme, D.; Sievers, A.; Tammi, J.; Ungerechts, H.

    2012-01-01

    We present more than three years of observations at different frequencies, from radio to high-energy ?-rays, of the Narrow-Line Seyfert 1 (NLS1) Galaxy PMN J0948+0022 (z = 0.585). This source is the first NLS1 detected at energies above 100 MeV and therefore can be considered the prototype of this emerging new class of ?-ray emitting active galactic nuclei (AGN). The observations performed from 2008 August 1 to 2011 December 31 confirmed that PMN J0948+0022 generates a powerful relativistic jet, which is able to develop an isotropic luminosity at gamma-rays of the order of 1048 erg per second, at the level of powerful quasars. The evolution of the radiation emission of this source in 2009 and 2010 followed the canonical expectations of relativistic jets with correlated multiwavelength variability (gamma-rays followed by radio emission after a few months), but it was difficult to retrieve a similar pattern in the light curves of 2011. The comparison of gamma-ray spectra before and including 2011 data suggested that there was a softening of the highenergy spectral slope. We selected five specific epochs to be studied by modelling the broad-band spectrum, which are characterised by an outburst at gamma-rays or very low/high flux at other wavelengths. The observed variability can largely be explained by changes in the injected power, the bulk Lorentz factor of the jet, or the electron spectrum. The characteristic time scale of doubling/halving flux ranges from a few days to a few months, depending on the frequency and the sampling rate. The shortest doubling time scale at gamma-rays is 2.3 +/- 0.5 days. These small values underline the need of highly sampled multiwavelength campaigns to better understand the physics of these sources.

  17. The peculiar radio-loud narrow line Seyfert 1 galaxy 1H 0323+342

    SciTech Connect

    Paliya, Vaidehi S.; Stalin, C. S.; Sahayanathan, S.; Parker, M. L.; Fabian, A. C.; Anjum, Ayesha; Pandey, S. B.

    2014-07-10

    We present a multiwavelength study of the radio-loud narrow-line Seyfert 1 galaxy (NLSy1) 1H 0323+342, detected by the Fermi Gamma-Ray Space Telescope. Multiband light curves show many orphan X-ray and optical flares having no corresponding γ-ray counterparts. Such anomalous variability behavior can be due to different locations of the emission region from the central source. During a large flare, a γ-ray flux doubling timescale as small as ∼3 hr is noticed. We built spectral energy distributions (SEDs) during different activity states and modeled them using a one-zone leptonic model. The shape of the optical/UV component of the SEDs is dominated by accretion disk emission in all the activity states. In the X-ray band, significant thermal emission from the hot corona is inferred during quiescent and first flaring states; however, during subsequent flares, the nonthermal jet component dominates. The γ-ray emission in all the states can be well explained by inverse-Compton scattering of accretion disk photons reprocessed by the broad-line region. The source showed violent intra-night optical variability, coinciding with one of the high γ-ray activity states. An analysis of the overall X-ray spectrum fitted with an absorbed power-law plus relativistic reflection component hints at the presence of an Fe Kα line and returns a high black hole spin value of a = 0.96 ± 0.14. We argue that 1H 0323+342 possesses dual characteristics, akin to both flat-spectrum radio quasars (FSRQs) and radio-quiet NLSy1 galaxies, though at a low jet power regime compared to powerful FSRQs.

  18. Reverberation Measurements of the Inner Radius of the Dust Torus in Nearby Seyfert 1 Galaxies

    NASA Astrophysics Data System (ADS)

    Suganuma, Masahiro; Yoshii, Yuzuru; Kobayashi, Yukiyasu; Minezaki, Takeo; Enya, Keigo; Tomita, Hiroyuki; Aoki, Tsutomu; Koshida, Shintaro; Peterson, Bruce A.

    2006-03-01

    The most intense monitoring observations yet made in the optical and near-infrared wave bands were carried out for Seyfert 1 galaxies NGC 5548, NGC 4051, NGC 3227, and NGC 7469 by the MAGNUM telescope, and clear time-delayed responses of the K-band flux variations to the V-band flux variations were found for all of these galaxies. Their H-K color temperatures of 1500-1800 K, estimated from their observed flux variation gradients, support a view that the bulk of the K flux should originate in the thermal radiation of hot dust surrounding the central engine and that the lag time should correspond to light-travel distance between them. Cross-correlation analysis measures their lag times to be 47-53 (NGC 5548), 11-18 (NGC 4051), about 20 (NGC 3227), and 65-87 (NGC 7469) days. The lag times are tightly correlated with the optical luminosities, as expected from dust reverberation (Δt~L0.5), while weakly with the central virial masses, which suggests that the inner radii of the dust tori around active nuclei have one-to-one correspondences with their central luminosities. In the lag time versus central luminosity diagram, the K-band lag times place an upper boundary on the similar lag times of broad emission lines in the literature, which not only supports the unified scheme of AGNs but also implies a physical transition from the BLR out to the dust torus that encircles the BLR. Correlated short-term V-band and X-ray flux variations in NGC 5548 are also found with a delay of 1 or 2 days, indicating the thermal reprocessing of X-ray emission by the central accretion flow.

  19. Photoionization Modeling of the Low-luminosity Seyfert 1 Nucleus in NGC 3516

    NASA Astrophysics Data System (ADS)

    Devereux, Nick

    2016-05-01

    Spectroscopic observations of the low-luminosity Seyfert 1 nucleus in NGC 3516 obtained with the Hubble Space Telescope show that the visible spectrum is dominated by Balmer emission lines of hydrogen (H) and a continuum luminosity that rises into the UV. The anomalous {{H}}α /Hβ emission line ratio, the Balmer emission line luminosity, and the distinctive shape observed for the {{H}}α emission line profile serve as important constraints for any photoionization model aimed at explaining the visible emission line spectrum of NGC 3516. Photoionization modeling using Cloudy demonstrates that the central UV-X-ray source is able to completely ionize the H gas in between the Balmer and dust reverberation radii if the electron density is ≤slant 3 × {10}7 cm{}-3 throughout. Thus, according to this model the region responsible for producing the visible H lines is a dust-free shell of ionized H gas. Interestingly, the model predicts a rapid rise in the electron temperature as the central UV-X-ray source is approached, mirrored by an equally precipitous decrease in the Balmer line emissivity that coincides with the Balmer reverberation radius, providing a natural explanation for the finite width observed for H Balmer lines. Collectively, the merit of the model is that it explains the relative intensities of the three brightest Balmer lines and the shape of the {{H}}α emission line profile. However, questions remain concerning the unusually weak forbidden lines that cannot be addressed using Cloudy due to limitations with the code.

  20. KILOPARSEC-SCALE JETS IN THREE RADIO-LOUD NARROW-LINE SEYFERT 1 GALAXIES

    SciTech Connect

    Richards, Joseph L.; Lister, Matthew L.

    2015-02-10

    We have discovered kiloparsec-scale extended radio emission in three narrow-line Seyfert 1 galaxies (NLS1s) in sub-arcsecond resolution 9 GHz images from the Karl G. Jansky Very Large Array. We find all sources show two-sided, mildly core-dominated jet structures with diffuse lobes dominated by termination hotspots. These span 20–70 kpc with morphologies reminiscent of FR II radio galaxies, while the extended radio luminosities are intermediate between FR I and FR II sources. In two cases the structure is linear, while a 45° bend is apparent in the third. Very Long Baseline Array images at 7.6 GHz reveal parsec-scale jet structures, in two cases with extended structure aligned with the inner regions of the kiloparsec-scale jets. Based on this alignment, the ratio of the radio core–luminosity to the optical luminosity, the jet/counter-jet intensity and extension length ratios, and moderate core brightness temperatures (≲10{sup 10} K), we conclude these jets are mildly relativistic (β≲0.3, δ∼1−1.5) and aligned at moderately small angles to the line of sight (10–15°). The derived kinematic ages of ∼10{sup 6}–10{sup 7} yr are much younger than radio galaxies but comparable to other NLS1s. Our results increase the number of radio-loud NLS1s with known kiloparsec-scale extensions from 7 to 10 and suggest that such extended emission may be common, at least among the brightest of these sources.

  1. The warm molecular gas and dust of Seyfert galaxies: two different phases of accretion?

    NASA Astrophysics Data System (ADS)

    Mezcua, M.; Prieto, M. A.; Fernández-Ontiveros, J. A.; Tristram, K.; Neumayer, N.; Kotilainen, J. K.

    2015-10-01

    The distribution of warm molecular gas (1000-3000 K), traced by the near-IR H2 2.12 μm line, has been imaged with a resolution <0.5 arcsec in the central 1 kpc of seven nearby Seyfert galaxies. We find that this gas is highly concentrated towards the central 100 pc and that its morphology is often symmetrical. Lanes of warm H2 gas are observed only in three cases (NGC 1068, NGC 1386 and Circinus) for which the morphology is much wider and extended than the dust filaments. We conclude that there is no one-to-one correlation between dust and warm gas. This indicates that, if the dust filaments and lanes of warm gas are radial streaming motions of fuelling material, they must represent two different phases of accretion: the dust filaments represent a colder phase than the gas close to the nucleus (within ˜100 pc). We predict that the morphology of the nuclear dust at these scales should resemble that of the cold molecular gas (e.g. CO at 10-40 K), as we show for CenA and NGC 1566 by Atacama Large Millimeter/submillimeter Array (ALMA) observations, whereas the inner H2 gas traces a much warmer phase of material identified with warmer (40-500 K) molecular gas such as CO(6-5) or HCN (as shown by ALMA for NGC 1068 and NGC 1097). We also find that X-ray heating is the most likely dominant excitation mechanism of the H2 gas for most sources.

  2. Kiloparsec-scale Radio Structures in Narrow-line Seyfert 1 Galaxies

    NASA Astrophysics Data System (ADS)

    Doi, Akihiro; Nagira, Hiroshi; Kawakatu, Nozomu; Kino, Motoki; Nagai, Hiroshi; Asada, Keiichi

    2012-11-01

    We report the finding of kiloparsec (kpc)-scale radio structures in three radio-loud narrow-line Seyfert 1 (NLS1) galaxies from the Faint Images of the Radio Sky at Twenty-centimeters of the Very Large Array, which increases the number of known radio-loud NLS1s with kpc-scale structures to six, including two γ-ray-emitting NLS1s (PMN J0948+0022 and 1H 0323+342) detected by the Fermi Gamma-ray Space Telescope. The detection rate of extended radio emissions in NLS1s is lower than that in broad-line active galactic nuclei (AGNs) with a statistical significance. We found both core-dominated (blazar-like) and lobe-dominated (radio-galaxy-like) radio structures in these six NLS1s, which can be understood in the framework of the unified scheme of radio-loud AGNs that considers radio galaxies as non-beamed parent populations of blazars. Five of the six NLS1s have (1) extended radio luminosities suggesting jet kinetic powers of >~ 1044 erg s-1, which is sufficient to make jets escape from hosts' dense environments; (2) black holes of >~ 107 M ⊙, which can generate the necessary jet powers from near-Eddington mass accretion; and (3) two-sided radio structures at kpc scales, requiring expansion rates of ~0.01c-0.3c and kinematic ages of >~ 107 years. On the other hand, most typical NLS1s would be driven by black holes of <~ 107 M ⊙ in a limited lifetime of ~107 years. Hence, the kpc-scale radio structures may originate in a small window of opportunity during the final stage of the NLS1 phase just before growing into broad-line AGNs.

  3. An Extreme, Blueshifted Iron Line in the Narrow Line Seyfert 1 PG 1402+261

    NASA Technical Reports Server (NTRS)

    Reeves, J. N.; Porquet, D.; Turner, T. J.

    2004-01-01

    We report on a short, XMM-Newton observation of the radio-quiet Narrow Line Seyfert 1 PG 1402+261. The EPIC X-ray spectrum of PG 1402+261 shows a strong excess of counts between 6 - 9 keV in the rest frame. This feature can be modeled by an unusually strong (equivalent width 2 keV) and very broad energy at 7.3 keV appears blue-shifted with respect to the iron Kalpha emission band between 6.4 - 6.97 keV, whilst the blue-wing of the line extends to 9 keV in the quasar rest frame. The line profile can be fitted by reflection from the inner accretion disk, but an inclination angle of greater than 60 degrees is required to model the extreme blue-wing of the line. Furthermore the extreme strength of the line requires a geometry whereby the hard X-ray emission from PG1402+261 above 2 keV is dominated by the pure-reflection component from the disk, whilst little or none of the direct hard power-law is observed. Alternatively the spectrum above 2 keV may instead be explained by an ionized absorber, if the column density is sufficiently high (NH greater than 3 x 10(exp 23) per square centimeter) and if the matter is ionized enough to produce a deep (tau approximately equal to 1) iron K-shell absorption edge at 9 keV. This absorber could originate in a large column density, high velocity outflow, perhaps similar to those which appear to be observed in several other high accretion rate AGN. Further observations, especially at higher spectral resolution, are required to distinguish between the accretion disk reflection or outflow scenarios.

  4. The Relativistic Iron Line Profile in the Seyfert 1 Galaxy IC4329a

    NASA Technical Reports Server (NTRS)

    Done, C.; Madejski, G. M.; Zycki, P. T.

    2000-01-01

    We present simultaneous ASCA and RXTE data on the bright Seyfert 1 galaxy IC4329a. The iron line is significantly broadened, but not to the extent expected from an accretion disk which extends down to the last stable orbit around a black hole. We marginally detect a narrow line component, presumably from the molecular torus, but, even including this gives a line profile from the accretion disk which is significantly narrower that that seen in MCG-6-30-15, and is much more like that seen from the low/hard state galactic black hole candidates. This is consistent with the inner disk being truncated before the last stable orbit, forming a hot flow at small radii as in the ADAF models. However. we cannot rule out the presence of an inner disk which does not contribute to the reflected spectrum. either because of extreme ionisation suppressing the characteristic atomic features of the reflected spectrum or because the X-ray source is intrinsically anisotropic, so it does not illuminate the inner disk. The source was monitored by RXTE every 2 days for 2 months, and these snapshot spectra show that there is intrinsic spectral variability. The data are good enough to disentangle the power law from the reflected continuum and we see that the power law softens as the source brightens. The lack of a corresponding increase in the observed reflected spectrum implies that either the changes in disk inner radial extent/ionization structure are small, or that the variability is actually driven by changes in the seed photons which are decoupled from the hard X-ray mechanism.

  5. Radiation mechanisms and physical properties of the γ-ray narrow-line Seyfert 1 galaxies

    NASA Astrophysics Data System (ADS)

    Yang, Jianping; Zhou, Bing

    2015-12-01

    We investigate the physical properties and radiation mechanisms of 11 states of five narrow-line Seyfert 1 (NLS1) galaxies detected by the Large Area Telescope on board Fermi through modeling the quasi-simultaneous multi-band observations. We obtain the best-fitting model parameters and their uncertainties for each state with the χ2-minimization procedure and discuss their implications on the characteristics of jet. Similar to blazars, their spectral energy distributions (SEDs) have a two-humped structure and their non-thermal emission can be modelled with the single-zone synchrotron + inverse Compton (IC) model. For all states, the GeV γ-rays may be contributed by the external Compton (EC) emission components. The observations of Fermi are mostly located at the declining stage of the EC humps. Text < 0.5 eV in all cases (Text is the characteristic temperature of external soft photons), suggesting that their radiation zones may be usually located outside of the broad line region (BLR) and the soft photons of Compton scattering mainly come from the dust torus. Compared with the bright Fermi blazars studied by Ghisellini et al. (2014, Nature, 515, 376), the Pjet (the power of the jets) of NLS1 galaxies detected by Fermi is similar to that of the flat spectrum radio quasars (FSRQs) but a little larger than that of the BL Lac objects (BL Lacs). However, a comparison of Pr (the powers of radiations) with the FSRQs and BL Lac objects shows that NLS1 galaxies' Pr has values comparable to BL Lac objects but lower than FSRQs in spite of having similar Pjet values and the same energy carrier (the cold protons) as the FSRQs. Observations indicate that γ-NLS1 galaxies might have lower η (efficiency of gravitational energy release) values than GeV blazars.

  6. SPECTRAL OPTICAL MONITORING OF THE NARROW-LINE SEYFERT 1 GALAXY Ark 564

    SciTech Connect

    Shapovalova, A. I.; Burenkov, A. N.; Popovic, L. C.; Kovacevic, J.; Chavushyan, V. H.; Valdes, J. R.; Torrealba, J.; Carrasco, L.; Ilic, D.; Kovacevic, A.; Kollatschny, W.; Bochkarev, N. G.; Leon-Tavares, J.; Mercado, A.; Benitez, E.; Dultzin, D.; De la Fuente, E.

    2012-09-15

    We present the results of a long-term (1999-2010) spectral optical monitoring campaign of the active galactic nucleus (AGN) Ark 564, which shows a strong Fe II line emission in the optical. This AGN is a narrow-line Seyfert 1 (NLS1) galaxy, a group of AGNs with specific spectral characteristics. We analyze the light curves of the permitted H{alpha}, H{beta}, optical Fe II line fluxes, and the continuum flux in order to search for a time lag between them. Additionally, in order to estimate the contribution of iron lines from different multiplets, we fit the H{beta} and Fe II lines with a sum of Gaussian components. We find that during the monitoring period the spectral variation (F{sub max}/F{sub min}) of Ark 564 is between 1.5 for H{alpha} and 1.8 for the Fe II lines. The correlation between the Fe II and H{beta} flux variations is of higher significance than that of H{alpha} and H{beta} (whose correlation is almost absent). The permitted-line profiles are Lorentzian-like and do not change shape during the monitoring period. We investigate, in detail, the optical Fe II emission and find different degrees of correlation between the Fe II emission arising from different spectral multiplets and the continuum flux. The relatively weak and different degrees of correlations between permitted lines and continuum fluxes indicate a rather complex source of ionization of the broad-line emission region.

  7. Fermi monitoring of radio-loud narrow-line Seyfert 1 galaxies

    SciTech Connect

    Paliya, Vaidehi S.; Stalin, C. S.; Ravikumar, C. D.

    2015-02-01

    We present detailed analysis of the γ-ray flux variability and spectral properties of the five radio-loud narrow line Seyfert 1 (RL-NLSy1) galaxies, detected by the Large Area Telescope on board the Fermi Gamma-Ray Space Telescope, namely 1H 0323+342, SBS 0846+513, PMN J0948+0022, PKS 1502+036, and PKS 2004−447. The first three sources show significant flux variations, including the rapid variability of a few hours by 1H 0323+342. The average γ-ray spectrum of 1H 0323+342 and PMN J0948+0022 shows deviation from a simple power-law (PL) behavior, whereas the PL model gives a better fit for the other three sources. The spectra of 1H 0323+342, SBS 0846+513, and PMN J0948+0022, which are in low, flaring, and moderately active states, respectively, show significant curvature. Such curvature in the γ-ray spectrum of 1H 0323+342 and PMN J0948+0022 could be due to the emission region located inside the broad line region (BLR) where the primary mechanism of the γ-ray emission is inverse-Compton (IC) scattering of BLR photons occurring in the Klein–Nishina regime. The γ-ray emission of SBS 0846+513 is explained by IC scattering of dusty torus photons, which puts the emission region outside the BLR and thus under the Thomson regime. Therefore, the observed curvature of SBS 0846+513 could be intrinsic to the particle energy distribution. The presence of curvature in the γ-ray spectrum and flux variability amplitudes of some of the RL-NLSy1 galaxies suggests that these sources could be akin to low/moderate jet power flat spectrum radio quasars.

  8. Measuring key X-ray parameters from simulated spectra of Seyfert galaxies

    NASA Astrophysics Data System (ADS)

    Bonson, K.; Gallo, L. C.

    2016-05-01

    Supermassive black hole (SMBH) accretion is an important topic of astrophysical research for a variety of fields. However, literature shows that precisely modelling the X-ray reflection component of an accretion disk around a SMBH is challenging. We test how reliably we can measure key active galactic nuclei (AGN) X-ray reflection parameters by simulating the spectra of average Seyfert 1 galaxies and then fitting those spectra using common modelling techniques. The AGN spectra were created from 0.01-300.0 keV using XMM-Newton pn responses and with (3.75±0.10)×106 counts in the 2-10 keV band. The model RELXILL was used to create all spectra with a reflection fraction (ratio of reflected flux over primary flux from 0.1-100 keV) of R = 1. The values of six key parameters were generated randomly within given ranges to simulate the spectra: photon index (Γ), inner emissivity index (q1), black hole spin (a), disk inclination angle (θ), ionization (ξ), and iron abundance in solar units (A_Fe). Once the simulated spectra were created, they were autonomously fit with RELXILL from 2.5-10.0 keV. All six key parameters were allowed to vary throughout the modelling process, with a gradual thawing of model parameters to mimic manual fitting procedure. We find that we can successfully measure key AGN spectral components in this scenario, but some conditions apply: Γ, θ, and A_Fe are well constrained, however they are also consistently overestimated. Only black hole spin (a) measurements that are in extrema, a > 0.9, can be considered reliable. Lastly, ξ and q1 cannot be measured and these parameters - along with intermediate spin values - should be verified using other techniques.

  9. Highly ionized disc and transient outflows in the Seyfert galaxy IRAS 18325-5926

    NASA Astrophysics Data System (ADS)

    Iwasawa, K.; Fabian, A. C.; Kara, E.; Reynolds, C. S.; Miniutti, G.; Tombesi, F.

    2016-08-01

    We report on strong X-ray variability and the Fe K-band spectrum of the Seyfert galaxy IRAS 18325-5926 obtained from the 2001 XMM-Newton EPIC pn observation with a duration of ~120 ks. While the X-ray source is highly variable, the 8-10 keV band shows larger variability than that of the lower energies. Amplified 8-10 keV flux variations are associated with two prominent flares of the X-ray source during the observation. The Fe K emission is peaked at 6.6 keV with moderate broadening. It is likely to originate from a highly ionized disc with an ionization parameter of log ξ ≃ 3. The Fe K line flux responds to the main flare, which supports its disc origin. A short burst of the Fe line flux has no relation to the continuum brightness, for which we have no clear explanation. We also find transient, blueshifted Fe K absorption features that can be identified with high-velocity (~0.2c) outflows of highly ionized gas, as found in other active galaxies. The deepest absorption feature appears only briefly (~1 h) at the onset of the main flare and disappears when the flare declines. The rapid evolution of the absorption spectrum makes this source peculiar among the active galaxies with high-velocity outflows. Another detection of the absorption feature also precedes the other flare. The variability of the absorption feature partly accounts for the excess variability in the 8-10 keV band where the absorption feature appears. Although no reverberation measurement is available, the black hole mass of ~2 × 106M⊙ is inferred from the X-ray variability. When this mass is assumed, the black hole is accreting at around the Eddington limit, which may fit the highly ionized disc and strong outflows observed in this galaxy.

  10. A massive dense gas cloud close to the nucleus of the Seyfert galaxy NGC 1068

    NASA Astrophysics Data System (ADS)

    Furuya, Ray S.; Taniguchi, Yoshiaki

    2016-10-01

    Using the ALMA archival data of both 12CO (6-5) line and 689-GHz continuum emission towards the archetypical Seyfert galaxy, NGC 1068, we identified a distinct continuum peak separated by 15 pc from the nuclear radio component S1 in projection. The continuum flux gives a gas mass of ˜2 × 105 M⊙ and bolometric luminosity of ˜108 L⊙, leading to a star formation rate of ˜0.1 M⊙ yr-1. Subsequent analysis on the line data suggest that the gas cloud has a size of ˜10 pc, yielding to a mean H2 number density of ˜105 cm-3. We therefore refer to the gas as a "massive dense gas cloud": the gas density is high enough to form a "protostar cluster" with a stellar mass of ˜104 M⊙. We found that the gas stands at a unique position between galactic and extraglactic clouds in the diagrams of start formation rate (SFR) vs. gas mass proposed by Lada et al. (2012, ApJ, 745, 190) and surface density of gas vs. SFR density by Krumholz and McKee (2005, ApJ, 630, 250). All the gaseous and star-formation properties may be understood in terms of the turbulence-regulated star formation scenario. Since there are two stellar populations with ages of 300 Myr and 30 Myr in the 100 pc scale circumnulear region, we discuss that NGC 1068 has experienced at least three episodic star-formation events with the likelihood that the inner star-forming region is the younger. Together with several lines of evidence that the dynamics of the nuclear region is decoupled from that of the entire galactic disk, we discuss that the gas inflow towards the nuclear region of NGC 1068 may be driven by a past minor merger.

  11. X-Ray Spectral and Temporal Analysis of Narrow Line Seyfert 1 Galaxy Was 61

    NASA Astrophysics Data System (ADS)

    Dou, Liming; Wang, Ting-Gui; Ai, Yanli; Yuan, Weimin; Zhou, Hongyan; Dong, Xiao-Bo

    2016-03-01

    We present an analysis of spectrum and variability of the bright reddened narrow line Seyfert 1 galaxy Was 61 using 90 ks archival XMM-Newton data. The X-ray spectrum in 0.2-10 keV can be characterized by an absorbed power-law plus soft excess and an Fe Kα emission line. The power-law spectral index remains constant during the flux variation. The absorbing material is mildly ionized, with a column density of 3.2 × 1021 cm-2, and does not appear to vary during the period of the X-ray observation. If the same material causes the optical reddening (E(B-V) ≃ 0.6 mag), it must be located outside the narrow line region with a dust-to-gas ratio similar to the average Galactic value. We detect significant variations of the Fe Kα line during the observational period. A broad Fe Kα line at ≃ 6.7 {{keV}} with a width of ˜0.6 keV is detected in the low flux segment of the first 40 ks exposure, and is absent in the spectra of other segments; a narrow Fe Kα emission line ˜6.4 keV with a width of ˜0.1 keV is observed in the subsequent 20 ks segment, which has a count rate 35% higher and is in the next day. We believe this is due to the change in geometry and kinematics of the X-ray emitting corona. The temperature and flux of soft X-ray excess appear to correlate with the flux of the hard power-law component. Comptonization of disc photons by a warm and optically thick inner disk is preferred to interpret the soft excess, rather than the ionized reflection.

  12. The Peculiar Radio-loud Narrow Line Seyfert 1 Galaxy 1H 0323+342

    NASA Astrophysics Data System (ADS)

    Paliya, Vaidehi S.; Sahayanathan, S.; Parker, M. L.; Fabian, A. C.; Stalin, C. S.; Anjum, Ayesha; Pandey, S. B.

    2014-07-01

    We present a multiwavelength study of the radio-loud narrow-line Seyfert 1 galaxy (NLSy1) 1H 0323+342, detected by the Fermi Gamma-Ray Space Telescope. Multiband light curves show many orphan X-ray and optical flares having no corresponding γ-ray counterparts. Such anomalous variability behavior can be due to different locations of the emission region from the central source. During a large flare, a γ-ray flux doubling timescale as small as ~3 hr is noticed. We built spectral energy distributions (SEDs) during different activity states and modeled them using a one-zone leptonic model. The shape of the optical/UV component of the SEDs is dominated by accretion disk emission in all the activity states. In the X-ray band, significant thermal emission from the hot corona is inferred during quiescent and first flaring states; however, during subsequent flares, the nonthermal jet component dominates. The γ-ray emission in all the states can be well explained by inverse-Compton scattering of accretion disk photons reprocessed by the broad-line region. The source showed violent intra-night optical variability, coinciding with one of the high γ-ray activity states. An analysis of the overall X-ray spectrum fitted with an absorbed power-law plus relativistic reflection component hints at the presence of an Fe Kα line and returns a high black hole spin value of a = 0.96 ± 0.14. We argue that 1H 0323+342 possesses dual characteristics, akin to both flat-spectrum radio quasars (FSRQs) and radio-quiet NLSy1 galaxies, though at a low jet power regime compared to powerful FSRQs.

  13. KILOPARSEC-SCALE RADIO STRUCTURES IN NARROW-LINE SEYFERT 1 GALAXIES

    SciTech Connect

    Doi, Akihiro; Kino, Motoki; Nagira, Hiroshi; Kawakatu, Nozomu; Nagai, Hiroshi; Asada, Keiichi

    2012-11-20

    We report the finding of kiloparsec (kpc)-scale radio structures in three radio-loud narrow-line Seyfert 1 (NLS1) galaxies from the Faint Images of the Radio Sky at Twenty-centimeters of the Very Large Array, which increases the number of known radio-loud NLS1s with kpc-scale structures to six, including two {gamma}-ray-emitting NLS1s (PMN J0948+0022 and 1H 0323+342) detected by the Fermi Gamma-ray Space Telescope. The detection rate of extended radio emissions in NLS1s is lower than that in broad-line active galactic nuclei (AGNs) with a statistical significance. We found both core-dominated (blazar-like) and lobe-dominated (radio-galaxy-like) radio structures in these six NLS1s, which can be understood in the framework of the unified scheme of radio-loud AGNs that considers radio galaxies as non-beamed parent populations of blazars. Five of the six NLS1s have (1) extended radio luminosities suggesting jet kinetic powers of {approx}> 10{sup 44} erg s{sup -1}, which is sufficient to make jets escape from hosts' dense environments; (2) black holes of {approx}> 10{sup 7} M {sub Sun }, which can generate the necessary jet powers from near-Eddington mass accretion; and (3) two-sided radio structures at kpc scales, requiring expansion rates of {approx}0.01c-0.3c and kinematic ages of {approx}> 10{sup 7} years. On the other hand, most typical NLS1s would be driven by black holes of {approx}< 10{sup 7} M {sub Sun} in a limited lifetime of {approx}10{sup 7} years. Hence, the kpc-scale radio structures may originate in a small window of opportunity during the final stage of the NLS1 phase just before growing into broad-line AGNs.

  14. AN OUTFLOW PERPENDICULAR TO THE RADIO JET IN THE SEYFERT NUCLEUS OF NGC 5929

    SciTech Connect

    Riffel, Rogemar A.; Storchi-Bergmann, Thaisa; Riffel, Rogério E-mail: thaisa@ufrgs.br

    2014-01-10

    We report the observation of an outflow perpendicular to the radio jet in near-infrared integral field spectra of the inner 250 pc of the Seyfert 2 galaxy NGC 5929. The observations were obtained with the Gemini Near-infrared Integral Field Spectrograph at a spatial resolution of ∼20 pc and spectral resolution of R ≈ 5300 and reveal a region ∼50 pc wide crossing the nucleus and extending by ∼300 pc perpendicularly to the known radio jet in this galaxy. Along this structure—which we call the south-east-north-west (SE-NW) strip—the emission line profiles show two velocity components, one blueshifted and the other redshifted by –150 km s{sup –1} and 150 km s{sup –1}, respectively, relative to the systemic velocity. We interpret these two components as being due to an outflow perpendicular to the radio jet, which is supported by low-frequency radio emission observed along the same region. We attribute this feature to the interaction of ambient gas with an ''equatorial outflow'' predicted in recent accretion disk and torus wind models. Perpendicularly to the SE-NW strip, thus approximately along the radio jet, single-component profiles show blueshifts of ≈ – 150 km s{sup –1} to the north-east and similar redshifts to the south-west, which can be attributed to gas counter-rotating relative to the stellar kinematics. More double-peaked profiles are observed in association with the two radio hot spots, attributed to interaction of the radio jet with the surrounding gas.

  15. Ultraviolet and X-ray Variability of the Seyfert 1.5 Galaxy Markarian 817

    NASA Astrophysics Data System (ADS)

    Winter, Lisa M.; Danforth, Charles; Vasudevan, Ranjan; Brandt, W. N.; Scott, Jennifer; Froning, Cynthia; Keeney, Brian; Shull, J. Michael; Penton, Steve; Mushotzky, Richard; Schneider, Donald P.; Arav, Nahum

    2011-02-01

    We present an investigation of the ultraviolet and X-ray spectra of the Seyfert 1.5 galaxy Markarian 817. The ultraviolet analysis includes two recent observations taken with the Cosmic Origins Spectrograph (COS) in 2009 August and December, as well as archival spectra from the International Ultraviolet Explorer and the Hubble Space Telescope. Twelve Lyα absorption features are detected in the 1997 Goddard High Resolution Spectrograph (GHRS) and 2009 COS spectra—of these, four are associated with high-velocity clouds in the interstellar medium, four are at low significance, and the remaining four are intrinsic features, which vary between the GHRS and COS observations. The strongest intrinsic absorber in the 1997 spectrum has a systemic velocity of ~-4250 km s-1. The corresponding feature in the COS data is five times weaker than the GHRS absorber. The three additional weak (equivalent width from 13 to 54 mÅ) intrinsic Lyα absorbers are at systemic velocities of -4100 km s-1, -3550 km s-1, and -2600 km s-1. However, intrinsic absorption troughs from highly ionized C IV and N V are not detected in the COS observations. No ionized absorption signatures are detected in the ~14 ks XMM-Newton EPIC spectra. The factor of five change in the intrinsic Lyα absorber is most likely due to bulk motions in the absorber, since there is no drastic change in the UV luminosity of the source from the GHRS to the COS observations. In a study of the variability of Mrk 817, we find that the X-ray luminosity varies by a factor of ~40 over 20 years, while the UV continuum/emission lines vary by at most a factor of ~2.3 over 30 years. The variability of the X-ray luminosity is strongly correlated with the X-ray power-law index, but no correlation is found with the simultaneous optical/UV photometry.

  16. X-rays and gamma-rays from accretion flows onto black holes in Seyferts and X-ray binaries

    NASA Technical Reports Server (NTRS)

    Zdziarski, Andrzej A.; Johnson, W. Neil; Poutanen, Juri; Magdziarz, Pawel; Gierlinski, Marek

    1997-01-01

    Observations and theoretical models of X-ray/gamma ray spectra of radio quiet Seyfert galaxies and Galactic black hole candidates are reviewed. The spectra from these objects share the following characteristics: an underlying power law with a high energy cutoff above 200 keV; a Compton reflection component with a Fe K alpha line, and a low energy absorption by intervening cold matter. The X-ray energy spectral index, alpha, is typically in the range between 0.8 and 1 in Seyfert spectra, and that of the hard state spectra of the black hole candidates Cygnus X-1 and GX 339-4 is typically between 0.6 and 0.8. The Compton reflection component corresponds with cold matter covering a solid angle of between 0.8pi and 2pi as seen from the X-ray source. The broadband spectra of both classes of sources are well fitted by Compton upscattering of soft photons in thermal plasma. The fits yield a thermal plasma temperature of 100 keV and the Thomson optical depth of 1. All the spectra presented are cut off before the electron rest energy 511 keV, indicating that electron/positron pair production is an important process.

  17. An XMM-Newton Observation of the Seyfert Galaxy 1H0419-577 in an Extreme Low State

    NASA Technical Reports Server (NTRS)

    Pounds, K. A.; Reeves, J. N.; Page, K. L.; O'Brien, P. T.

    2003-01-01

    Previous observations of the luminous Seyfert galaxy 1H 0419-577 have found its X-ray spectrum to range from that of a typical Seyfert 1 with 2-10 keV power law index Gamma approx. 1.9 to a much flatter power law of Gamma approx. 1.5 or less. We report here a new XMM-Newton observation which allows the low state spectrum to be studied in much greater detail than hitherto. We find a very hard spectrum (Gamma approx. 1.0) which exhibits broad features that can be modelled with the addition of an extreme relativistic Fe K emission line or with partial covering of the underlying continuum by a substantial column density of near-neutral gas. Both the EPIC and RGS data show evidence for strong line emission of OVII and OVIII requiring an extended region of low density photoionised gas in 1H 0419- 577. Comparison with an earlier XMM-Newton observation when 1H 0419-577 was X-ray bright indicates the dominant spectral variability occurs via a steep power law component.

  18. An XMM-Newton Observation of the Seyfert 1 Galaxy 1H 0419-577 in an Extreme Low State

    NASA Technical Reports Server (NTRS)

    Pounds, K. A.; Reeves, J. N.; Page, K. L.; OBrien, P. T.

    2004-01-01

    Previous observations of the luminous Seyfert 1 galaxy 1H 0419-577 have found its X-ray spectrum to range from that of a typical Seyfert 1 with 2-10 keV power law index Gamma approx. 1.9 to a much flatter power law of Gamma approx. 1.5 or less. We report here a new XMM-Newton observation which allows the low state spectrum to be studied in much greater detail than hitherto. We find a very hard spectrum (Gamma approx. 1.0), which exhibits broad features that can be modelled myth the addition of an extreme relativistic Fe K emission line or with partial covering of the underlying continuum by a substantial column density of near-neutral gas. Both the EPIC and RGS data show evidence for strong line emission of OVII and OVIII requiring an extended region of low density photoionised gas in 1H 0419-577. Comparison with an earlier XMM-Newton observation when 1H 0419-577 was 'X-ray bright' indicates the dominant spectral variability occurs via a steep power law component.

  19. Radio Jets Clearing the Way Through a Galaxy: Watching Feedback in Action in the Seyfert Galaxy IC 5063

    NASA Astrophysics Data System (ADS)

    Morganti, R.; Oosterloo, T. A.; Oonk, J. B. R.; Frieswijk, W.; Tadhunter, C. N.

    2015-12-01

    High-resolution (0.5 arcsec) CO(2-1) observations performed with the Atacama Large Millimetre/submillimetre Array have been used to trace the kinematics of the molecular gas in the Seyfert 2 galaxy{IC 5063}. Although one of the most radio-loud Seyfert galaxy, IC 5063 is a relatively weak radio source (P1.4GHz=3 ×1023 W Hz-1). The data reveal that the kinematics of the gas is very complex. A fast outflow of molecular gas extends along the entire radio jet (˜ 1 kpc), with the highest outflow velocities about 0.5 kpc from the nucleus, at the location of the brighter hot-spot in the W lobe. All the observed characteristics can be described by a scenario of a radio plasma jet expanding into a clumpy medium, interacting directly with the clouds and inflating a cocoon that drives a lateral outflow into the interstellar medium. This suggests that most of the observed cold molecular outflow is due to fast cooling of the gas after the passage of a shock and that it is the end product of the cooling process.

  20. Compact steep-spectrum sources as the parent population of flat-spectrum radio-loud narrow-line Seyfert 1 galaxies

    NASA Astrophysics Data System (ADS)

    Berton, M.; Caccianiga, A.; Foschini, L.; Peterson, B. M.; Mathur, S.; Terreran, G.; Ciroi, S.; Congiu, E.; Cracco, V.; Frezzato, M.; La Mura, G.; Rafanelli, P.

    2016-06-01

    Narrow-line Seyfert 1 galaxies (NLS1s) are an interesting subclass of active galactic nuclei (AGN), which tipically does not exhibit any strong radio emission. Seven percent of them, though, are radio-loud and often show a flat radio-spectrum (F-NLS1s). This, along to the detection of γ-ray emission coming from them, is usually interpreted as a sign of a relativistic beamed jet oriented along the line of sight. An important aspect of these AGN that must be understood is the nature of their parent population, in other words how do they appear when observed under different angles. In the recent literature it has been proposed that a specific class of radio-galaxies, compact-steep sources (CSS) classified as high excitation radio galaxies (HERG), can represent the parent population of F-NLS1s. To test this hypothesis in a quantitative way,in this paper we analyzed the only two statistically complete samples of CSS/HERGs and F-NLS1s available in the literature. We derived the black hole mass and Eddington ratio distributions, and we built for the first time the radio luminosity function of F-NLS1s. Finally, we applied a relativistic beaming model to the luminosity function of CSS/HERGs, and compared the result with the observed function of F-NLS1s. We found that compact steep-spectrum sources are valid parent candidates and that F-NLS1s, when observed with a different inclination, might actually appear as CSS/HERGs.

  1. Constraining Properties of AGN Coronae with NuSTAR: the Case of the Obscured Seyfert 1.9 Nucleus MCG -05-23-016

    NASA Astrophysics Data System (ADS)

    Balokovic, Mislav; Harrison, Fiona

    2016-04-01

    Robust measurements of the high-energy cut-off in the coronal continuum of AGN have long been limited to a small set of the brightest examples and almost exclusively to unobscured nuclei. We report on a direct measurement of the cut-off energy in the nuclear continuum of the obscured Seyfert 1.9 nucleus MCG-05-23-016 with unprecedented precision. The high sensitivity of NuSTAR in the hard X-ray band allows us to clearly disentangle the spectral curvature of the primary continuum from that of the reprocessed component. Using a simple phenomenological spectral model, we measured the cut-off energy to be 116+/-6 keV, while more complex Comptonization models provided independent constraints on the kinetic temperature of the electrons in the corona and its optical depth. Similar to a number of such measurements perfomed with NuSTAR in the past few years, and consistent with analyses of relatively large samples of hard X-ray spectra from the NuSTAR survey of nearby AGN, the optical depth was found to be of order unity for a range of assumed simple geometries. This means that the data are pushing the currently available models to the limits of their validity. In combination with the observations of spectral signatures from the innermost region of the accretion disk, and the observed variability of the high-energy cut-off, these results allow us to constrain the spatial extent of the AGN corona, its inhomogeneity and physical conditions needed to maintain its structure.

  2. Studying the Iron Line Complex in the Bright Seyfert Galaxy NGC 5506

    NASA Technical Reports Server (NTRS)

    Nicastro, Fabrizio; Atkins, Patricia M. (Technical Monitor)

    2002-01-01

    This grant was to support the reduction and analysis of our approved XMM observation of the nearby Seyfert 2 galaxy NGC 5506. The observation has been carried out simultaneously with a BeppoSAX observation of the same source. The proposal was aimed to study in detail the Compton reflection component and the complex Iron K line of this source, combining the still unique capability of BeppoSAX in hard X-rays (to strongly constrain the reflection component, and then the intrinsic nuclear continuum), and the sensitivity of XMM at the energy of the Iron Line complex. NGC 5506 is one of the brightest AGN in hard X-rays and has been intensively studied in the past. GINGA detected the complex iron line as well as the reflection component. Both ASCA (spectroscopically) and Rossi-XTE (through variability analysis) suggested that the FeK line is complex, possibly made up of several distinct components. The centroid of the FeK complex in a subsequent BeppoSAX observation was bluer than the 6.4 keV energy of the relatively low-ionization iron Kalpha transition. NGC 5506 has been observed simultaneously by NewtonXMM and BeppoSAX on February 2-3 2001. we have reduced and analyzed both the NewtonXMM and the BeppoSAX data, and have written and published a paper on our results (appeared in Volume 377 (page 31) of A&A-Letters). Our main results can be summarized as follows: (a) we confirm that the FeK line is complex, and for the first time disentangle its components: we find that at least two components made up the FeK complex, one neutral and narrow, at 6.4 keV (rest energy), and another one either broader and highly ionized, at about 6.7 keV (rest frame), or, in turn, made up of two narrow and unresolved components from the He-like and the H-like ions of Fe; (b) the two possible solution for the high-ionization Fe-K component, are statistically indistinguishable. However, physically, a blend of two narrow lines from photoionized matter seems to be preferable to emission of a

  3. Multi-wavelength study of the Seyfert 1 galaxy NGC 3783 with XMM-Newton

    NASA Astrophysics Data System (ADS)

    Blustin, A. J.; Branduardi-Raymont, G.; Behar, E.; Kaastra, J. S.; Kahn, S. M.; Page, M. J.; Sako, M.; Steenbrugge, K. C.

    2002-09-01

    We present the analysis of multi-wavelength XMM-Newton data from the Seyfert galaxy NGC 3783, including UV imaging, X-ray and UV lightcurves, the 0.2-10 keV X-ray continuum, the iron Kalpha emission line, and high-resolution spectroscopy and modelling of the soft X-ray warm absorber. The 0.2-10 keV spectral continuum can be well reproduced by a power-law at higher energies; we detect a prominent Fe Kalpha emission line, with both broad and narrow components, and a weaker emission line at 6.9 keV which is probably a combination of Fe Kbeta and Fe Xxvi. We interpret the significant deficit of counts in the soft X-ray region as being due to absorption by ionised gas in the line of sight. This is demonstrated by the large number of narrow absorption lines in the RGS spectrum from iron, oxygen, nitrogen, carbon, neon, argon, magnesium, silicon and sulphur. The wide range of iron states present in the spectrum enables us to deduce the ionisation structure of the absorbing medium. We find that our spectrum contains evidence of absorption by at least two phases of gas: a hotter phase containing plasma with a log ionisation parameter xi (where xi is in erg cm s-1) of 2.4 and greater, and a cooler phase with log xi centred around 0.3. The gas in both phases is outflowing at speeds of around 800 km s-1. The main spectral signature of the cold phase is the Unresolved Transition Array (UTA) of M-shell iron, which is the deepest yet observed; its depth requires either that the abundance of iron, in the cold phase, is several times that of oxygen, with respect to solar abundances, or that the absorption lines associated with this phase are highly saturated. The cold phase is associated with ionisation states that would also absorb in the UV.

  4. The Far-Infrared Emission Line and Continuum Spectrum of the Seyfert Galaxy NGC 1068

    NASA Technical Reports Server (NTRS)

    Spinoglio, Luigi; Smith, Howard A.; Gonzalez-Alfonso, Eduardo; Fisher, Jacqueline

    2005-01-01

    We report on the analysis of the first complete far-infrared spectrum (43-197 microns) of the Seyfert 2 galaxy NGC 1068 as observed with the Long Wavelength Spectrometer (LWS) onboard the Infrared Space Observatory (ISO). In addition to the 7 expected ionic fine structure emission lines, the OH rotational lines at 79, 119 and 163 microns were all detected in emission, which is unique among galaxies with full LWS spectra, where the 119 micron line, where detected, is always in absorption. The observed line intensities were modelled together with IS0 Short Wavelength Spectrometer (SWS) and optical and ultraviolet line intensities from the literature, considering two independent emission components: the AGN component and the starburst component in the circumnuclear ring of approximately 3kpc in size. Using the UV to mid-IR emission line spectrum to constrain the nuclear ionizing continuum, we have confirmed previous results: a canonical power-law ionizing spectrum is a poorer fit than one with a deep absorption trough, while the presence of a big blue bump is ruled out. Based on the instantaneous starburst age of 5 Myr constrained by the Br gamma equivalent width in the starburst ring, and starburst synthesis models of the mid- and far-infrared fine-structure line emission, a low ionization parameter (U=10(exp -3.5)) and low densities (n=100 cm (exp -3)) are derived. Combining the AGN and starburst components, we succeed in modeling the overall UV to far-IR atomic spectrum of SGC 1068, reproducing the line fluxes to within a factor 2.0 on average with a standard deviation of 1.4. The OH 119 micron emission indicates that the line is collisionally excited, and arises in a warm and dense region. The OH emission has been modeled using spherically symmetric, non-local, non-LTE radiative transfer models. The models indicate that the bulk of the emission arises from the nuclear region, although some extended contribution from the starburst is not ruled out. The OH abundance

  5. FAR-INFRARED LINE SPECTRA OF SEYFERT GALAXIES FROM THE HERSCHEL-PACS SPECTROMETER

    SciTech Connect

    Spinoglio, Luigi; Pereira-Santaella, Miguel; Busquet, Gemma; Dasyra, Kalliopi M.; Calzoletti, Luca; Malkan, Matthew A.; Tommasin, Silvia

    2015-01-20

    We observed the far-IR fine-structure lines of 26 Seyfert galaxies with the Herschel-PACS spectrometer. These observations are complemented with Spitzer Infrared Spectrograph and Herschel SPIRE spectroscopy. We used the ionic lines to determine electron densities in the ionized gas and the [C I] lines, observed with SPIRE, to measure the neutral gas densities, while the [O I] lines measure the gas temperature, at densities below ∼10{sup 4} cm{sup –3}. Using the [O I]145 μm/63 μm and [S III]33/18 μm line ratios, we find an anti-correlation of the temperature with the gas density. Various fine-structure line ratios show density stratifications in these active galaxies. On average, electron densities increase with the ionization potential of the ions. The infrared lines arise partly in the narrow line region, photoionized by the active galactic nucleus (AGN), partly in H II regions photoionized by hot stars, and partly in photo-dissociated regions. We attempt to separate the contributions to the line emission produced in these different regions by comparing our observed emission line ratios to theoretical values. In particular, we tried to separate the contribution of AGNs and star formation by using a combination of Spitzer and Herschel lines, and we found that besides the well-known mid-IR line ratios, the line ratio of [O III]88 μm/[O IV]26 μm can reliably discriminate the two emission regions, while the far-IR line ratio of [C II]157 μm/[O I]63 μm is only able to mildly separate the two regimes. By comparing the observed [C II]157 μm/[N II]205 μm ratio with photoionization models, we also found that most of the [C II] emission in the galaxies we examined is due to photodissociation regions.

  6. ALMA reveals the feeding of the Seyfert 1 nucleus in NGC 1566

    NASA Astrophysics Data System (ADS)

    Combes, F.; García-Burillo, S.; Casasola, V.; Hunt, L. K.; Krips, M.; Baker, A. J.; Boone, F.; Eckart, A.; Marquez, I.; Neri, R.; Schinnerer, E.; Tacconi, L. J.

    2014-05-01

    We report ALMA observations of CO(3-2) emission in the Seyfert 1 galaxy NGC 1566, at a spatial resolution of 25 pc. Our aim is to investigate the morphology and dynamics of the gas inside the central kpc, and to probe nuclear fueling and feedback phenomena. NGC 1566 has a nuclear bar of 1.7 kpc radius and a conspicuous grand design spiral starting from this radius. The ALMA field of view, of diameter 0.9 kpc, lies well inside the nuclear bar and reveals a molecular trailing spiral structure from 50 to 300 pc in size, which is contributing to fuel the nucleus, according to its negative gravity torques. The spiral starts with a large pitch angle from the center and then winds up in a pseudo-ring at the inner Lindblad resonance (ILR) of the nuclear bar. This is the first time that a trailing spiral structure is clearly seen driving the gas inwards inside the ILR ring of the nuclear bar. This phenomenon shows that the massive central black hole has a significant dynamical influence on the gas, triggering its fueling. The gaseous spiral is well correlated with the dusty spiral seen through extinction in HST images, and also with a spiral feature emitting 0.87 mm continuum. This continuum emission must come essentially from cold dust heated by the interstellar radiation field. The HCN(4-3) and HCO+(4-3) lines were simultaneously mapped and detected in the nuclear spiral. The HCO+(4-3) line is 3 times stronger than the HCN(4-3), as expected when star formation excitation dominates over active galactic nucleus (AGN) heating. The CO(3-2)/HCO+(4-3) integrated intensity ratio is ~100. The molecular gas is in remarkably regular rotation, with only slight non-circular motions at the periphery of the nuclear spiral arms. These perturbations are quite small, and no outflow nor AGN feedback is detected. Based on observations carried out with ALMA in cycle 0.

  7. Infrared coronal emission lines and the possibility of their maser emission in Seyfert nuclei

    NASA Technical Reports Server (NTRS)

    Greenhouse, Matthew A.; Feldman, Uri; Smith, Howard A.; Klapisch, Marcel; Bhatia, Anand K.; Bar-Shalom, Abi

    1993-01-01

    Energetic emitting regions have traditionally been studied via x-ray, UV and optical emission lines of highly ionized intermediate mass elements. Such lines are often referred to as 'coronal lines' since the ions, when produced by collisional ionization, reach maximum abundance at electron temperatures of approx. 10(exp 5) - 10(exp 6) K typical of the sun's upper atmosphere. However, optical and UV coronal lines are also observed in a wide variety of Galactic and extragalactic sources including the Galactic interstellar medium, nova shells, supernova remnants, galaxies and QSOs. Infrared coronal lines are providing a new window for observation of energetic emitting regions in heavily dust obscured sources such as infrared bright merging galaxies and Seyfert nuclei and new opportunities for model constraints on physical conditions in these sources. Unlike their UV and optical counterparts, infrared coronal lines can be primary coolants of collisionally ionized plasmas with 10(exp 4) less than T(sub e)(K) less than 10(exp 6) which produce little or no optical or shorter wavelength coronal line emission. In addition, they provide a means to probe heavily dust obscured emitting regions which are often inaccessible to optical or UV line studies. In this poster, we provide results from new model calculations to support upcoming Infrared Space Observatory (ISO) and current ground-based observing programs involving infrared coronal emission lines in AGN. We present a complete list of infrared (lambda greater than 1 micron) lines due to transitions within the ground configurations 2s(2)2p(k) and 3s(2)3p(k) (k = 1 to 5) or the first excited configurations 2s2p and 3s3p of highly ionized (x greater than or equal to 100 eV) astrophysically abundant (n(X)/n(H) greater than or equal to 10(exp -6)) elements. Included are approximately 74 lines in ions of O, Ne, Na, Mg, Al, Si, S, Ar, Ca, Fe, and Ni spanning a wavelength range of approximately 1 - 280 microns. We present new

  8. FIREWORKS NEAR A BLACK HOLE IN THE CORE OF SEYFERT GALAXY NGC 4151

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The Space Telescope Imaging Spectrograph (STIS) simultaneously records, in unprecedented detail, the velocities of hundreds of gas knots streaming at hundreds of thousands of miles per hour from the nucleus of NGC 4151, thought to house a supermassive black hole. This is the first time the velocity structure in the heart of this object, or similar objects, has been mapped so vividly this close to its central black hole. The twin cones of gas emission are powered by the energy released from the supermassive black hole believed to reside at the heart of this Seyfert galaxy. The STIS data clearly show that the gas knots illuminated by one of these cones is rapidly moving towards us, while the gas knots illuminated by the other cone are rapidly receding. The images have been rotated to show the same orientation of NGC 4151. The figures show: WFPC2 (upper left) -- A Hubble Wide Field Planetary Camera 2 image of the oxygen emission (5007 Angstroms) from the gas at the heart of NGC 4151. Though the twin cone structure can be seen, the image does not provide any information about the motion of the oxygen gas. STIS OPTICAL (upper right) -- In this STIS spectral image of the oxygen gas, the velocities of the knots are determined by comparing the knots of gas in the stationary WFPC2 image to the horizontal location of the knots in the STIS image. STIS OPTICAL (lower right) -- In this false color image the two emission lines of oxygen gas (the weaker one at 4959 Angstroms and the stronger one at 5007 Angstroms) are clearly visible. The horizontal line passing through the image is from the light generated by the powerful black hole at the center of NGC 4151. STIS ULTRAVIOLET (lower left) -- This STIS spectral image shows the velocity distribution of the carbon emission from the gas in the core of NGC 4151. It requires more energy to make the carbon gas glow (CIV at 1549 Angstroms) than it does to ionize the oxygen gas seen in the other images. This means we expect that the

  9. The Far-Infrared Emission Line and Continuum Spectrum of the Seyfert Galaxy NGC 1068

    NASA Astrophysics Data System (ADS)

    Spinoglio, Luigi; Malkan, Matthew A.; Smith, Howard A.; González-Alfonso, Eduardo; Fischer, Jacqueline

    2005-04-01

    We report on the analysis of the first complete far-infrared spectrum (43-197 μm) of the Seyfert 2 galaxy NGC 1068 as observed with the Long Wavelength Spectrometer (LWS) on board the Infrared Space Observatory (ISO). In addition to the seven expected ionic fine-structure emission lines, the OH rotational lines at 79, 119, and 163 μm were all detected in emission, which is unique among galaxies with full LWS spectra, where the 119 μm line, when detected, is always in absorption. The observed line intensities were modeled together with ISOShort Wavelength Spectrometer (SWS) and optical and ultraviolet line intensities from the literature, considering two independent emission components: the active galactic nucleus (AGN) component and the starburst component in the circumnuclear ring of ~3 kpc in size. Using the UV to mid-IR emission line spectrum to constrain the nuclear ionizing continuum, we have confirmed previous results: a canonical power-law ionizing spectrum is a poorer fit than one with a deep absorption trough, while the presence of a `` big blue bump'' is ruled out. Based on the instantaneous starburst age of 5 Myr constrained by the Brγ equivalent width in the starburst ring, and starburst synthesis models of the mid- and far-infrared fine-structure line emission, a low-ionization parameter (U=10-3.5) and low densities (n=100 cm-3) are derived. Combining the AGN and starburst components, we succeeded in modeling the overall UV to far-IR atomic spectrum of NGC 1068, reproducing the line fluxes to within a factor of 2.0 on average with a standard deviation of 1.3, and the overall continuum as the sum of the contribution of the thermal dust emission in the ionized and neutral components. The OH 119 μm emission indicates that the line is collisionally excited and arises in a warm and dense region. The OH emission has been modeled using spherically symmetric, nonlocal, non-LTE radiative transfer models. The models indicate that the bulk of the emission

  10. The gamma-ray emitting radio-loud narrow-line Seyfert 1 galaxy PKS 2004-447. II. The radio view

    NASA Astrophysics Data System (ADS)

    Schulz, R.; Kreikenbohm, A.; Kadler, M.; Ojha, R.; Ros, E.; Stevens, J.; Edwards, P. G.; Carpenter, B.; Elsässer, D.; Gehrels, N.; Großberger, C.; Hase, H.; Horiuchi, S.; Lovell, J. E. J.; Mannheim, K.; Markowitz, A.; Müller, C.; Phillips, C.; Plötz, C.; Quick, J.; Trüstedt, J.; Tzioumis, A. K.; Wilms, J.

    2016-04-01

    Context. Γ-ray-detected radio-loud narrow-line Seyfert 1 (γ-NLS1) galaxies constitute a small but interesting sample of the γ-ray-loud AGN. The radio-loudest γ-NLS1 known, PKS 2004-447, is located in the southern hemisphere and is monitored in the radio regime by the multiwavelength monitoring programme TANAMI. Aims: We aim for the first detailed study of the radio morphology and long-term radio spectral evolution of PKS 2004-447, which are essential for understanding the diversity of the radio properties of γ-NLS1s. Methods: The TANAMI VLBI monitoring program uses the Australian Long Baseline Array (LBA) and telescopes in Antarctica, Chile, New Zealand, and South Africa to monitor the jets of radio-loud active galaxies in the southern hemisphere. Lower resolution radio flux density measurements at multiple radio frequencies over four years of observations were obtained with the Australia Telescope Compact Array (ATCA). Results: The TANAMI VLBI image at 8.4 GHz shows an extended one-sided jet with a dominant compact VLBI core. Its brightness temperature is consistent with equipartition, but it is an order of magnitude below other γ-NLS1s with the sample value varying over two orders of magnitude. We find a compact morphology with a projected large-scale size < 11 kpc and a persistent steep radio spectrum with moderate flux-density variability. Conclusions: PKS 2004-447 appears to be a unique member of the γ-NLS1 sample. It exhibits blazar-like features, such as a flat featureless X-ray spectrum and a core-dominated, one-sided parsec-scale jet with indications for relativistic beaming. However, the data also reveal properties atypical for blazars, such as a radio spectrum and large-scale size consistent with compact-steep-spectrum (CSS) objects, which are usually associated with young radio sources. These characteristics are unique among all γ-NLS1s and extremely rare among γ-ray-loud AGN. The VLBI images shown in Figs. 3 and 4 (as FITS files) and the ATCA

  11. Gamma-ray emitting narrow-line Seyfert 1 galaxies and their place in the AGN zoo

    NASA Astrophysics Data System (ADS)

    D'Ammando, Filippo; Orienti, Monica; Finke, Justin; Giroletti, Marcello; Larsson, Josefin

    2016-08-01

    Relativistic jets are usually produced by radio-loud AGN hosted in giant elliptical galaxies such as blazars and radio galaxies. The discovery by Fermi-LAT of variable gamma-ray emission from narrow-line Seyfert 1 (NLSy1) galaxies revealed the presence of a new class of AGN with relativistic jets. Considering that NLSy1 are usually hosted in spiral galaxies, this finding poses intriguing questions about the nature of these objects and the formation of relativistic jets. In this talk I discuss the radio-to-gamma-ray properties of the gamma-ray NLSy1 detected during the first 7 years of Fermi operation, the observations of their host galaxies, and the estimation of their black hole masses.

  12. On the origin of the Z-shaped narrow-line region in the Seyfert galaxy NGC 3516

    NASA Technical Reports Server (NTRS)

    Veilleux, Sylvain; Tully, R. B.; Bland-Hawthorn, Jonathan

    1993-01-01

    A kinematic study has been carried out of the line-emitting gas in the Seyfert galaxy NGC 3516. The existence of two curved filaments in the central 2.5 kpc of this galaxy, which give Z-shaped appearance to its NLR. A precessing twin-jet model in which the line-emitting material is entrained by a precessing radio jet and kept ionized by the nuclear ionization field can explain the kinematic data of the brightest emission rather well. If this model is valid, this would make NGC 3516 the least luminous known active galaxy with a precessing jet. An alternative scenario assumes that the curved inner filaments represent gas entrained by a radio jet which is deflected by ram pressure from the rotation interstellar medium of the galaxy.

  13. The X-ray Reflectors in the Nucleus of the Seyfert Galaxy NGC 1068

    NASA Technical Reports Server (NTRS)

    Colbert, Edward J. M.; Weaver, Kimberly A.; Krolik, Julian H.; Mulchaey, John S.; Mushotzky, Richard F.; White, Nicholas E. (Technical Monitor)

    2002-01-01

    Based on observations of the Seyfert nucleus in NGC 1068 with ASCA, RXTE and BeppoSAX, we report the discovery of a flare (increase in flux by a factor of approximately 1.6) in the 6.7 keV Fe K line component between observations obtained four months apart, with no significant change in the other (6.21, 6.4, and 6.97 keV) Fe Kalpha line components. During this time, the continuum flux decreased by approximately 20%. The RXTE spectrum requires an Fe K absorption edge near 8.6 keV (Fe XXIII- XXV). The spectral data indicate that the 2-10 keV continuum emission is dominated (approximately 2/3 of the luminosity) by reflection from a previously unidentified region of warm, ionized gas located approximately or less than 0.2 pc from the AGN. The remaining approximately 1/3 of the observed X-ray emission is reflected from optically thick, neutral gas. The coronal gas in the inner Narrow-Line Region (NLR) and/or the cold gas at the inner surface of the obscuring 'torus' are possible cold reflectors. The inferred properties of the warm reflector are: size (diameter) approximately or less than 0.2 pc, gas density n approximately or greater than 10(exp 5.5)/cu cm, ionization parameter xi is approximately 10(exp 3.5) erg cm s(exp -1), and covering fraction 0.003 (L(sub 0)/ 10(exp 43.5) erg s(exp -1)(exp -1) less than (omega/4pi) less than 0.024 (L(sub 0)/ 10(exp 43.5) erg s(exp -1) (exp -1) where L(sub 0) is the intrinsic 2-10 keV X-ray luminosity of the AGN. We suggest that the warm reflector gas is the source of the (variable) 6.7 keV Fe line emission, and the 6.97 keV Fe line emission. The 6.7 keV line flare is assumed to be due to an increase in the emissivity of the warm reflector gas from a decrease (by 20-30%) in L(sub 0). The properties of the warm reflector are most consistent with an intrinsically X-ray weak AGN with L(sub 0) approximately equals 10(exp 43.0) erg s(exp -1). The optical and UV emission that scatters from the warm reflector into our line of sight is

  14. THE TWO-PHASE, TWO-VELOCITY IONIZED ABSORBER IN THE SEYFERT 1 GALAXY NGC 5548

    SciTech Connect

    Andrade-Velazquez, Mercedes; Krongold, Yair; Binette, Luc; Jimenez-Bailon, Elena; Elvis, Martin; Nicastro, Fabrizio; Brickhouse, Nancy; Mathur, Smita

    2010-03-10

    We present an analysis of X-ray high-quality grating spectra of the Seyfert 1 galaxy NGC 5548 using archival Chandra-High Energy Transmission Grating Spectrometer and Low Energy Transmission Grating Spectrometer observations for a total exposure time of 800 ks. The continuum emission (between 0.2 keV and 8 keV) is well represented by a power law (GAMMA = 1.6) plus a blackbody component (kT = 0.1 keV). We find that the well-known X-ray warm absorber (WA) in this source consists of two different outflow velocity systems. One absorbing system has a velocity of -1110 +- 150 km s{sup -1} and the other of -490 +- 150 km s{sup -1}. Recognizing the presence of these kinematically distinct components allows each system to be fitted independently, each with two absorption components with different ionization levels. The high-velocity system consists of two components, one with a temperature of 2.7 +- 0.6 x 10{sup 6} K, log U = 1.23, and another with a temperature of 5.8 +- 1.0 x 10{sup 5} K, log U = 0.67. The high-velocity, high-ionization component produces absorption by charge states Fe XXI-XXIV, while the high-velocity, low-ionization component produces absorption by Ne IX-X, Fe XVII-XX, and O VII-VIII. The low-velocity system also required two absorbing components, one with a temperature of 5.8 +- 0.8 x 10{sup 5} K, log U = 0.67, producing absorption by Ne IX-X, Fe XVII-XX, and O VII-VIII, and the other with a lower temperature of 3.5 +- 0.35 x 10{sup 4} K and a lower ionization of log U = -0.49, producing absorption by O VI-VII and the Fe VII-XII M-shell Unresolved Transitions Array. Once these components are considered, the data do not require any further absorbers. In particular, a model consisting of a continuous radial range of ionization structures (as suggested by a previous analysis) is not required. The two absorbing components in each velocity system are in pressure equilibrium with each other. This suggests that each velocity system consists of a multi

  15. High-frequency excess in the radio continuum spectrum of the type-1 Seyfert galaxy NGC 985

    NASA Astrophysics Data System (ADS)

    Doi, Akihiro; Inoue, Yoshiyuki

    2016-08-01

    The Seyfert galaxy NGC 985 is known to show a high-frequency excess in its radio continuum spectrum at a milli-Jansky level on the basis of previous observations at 1.4-15 GHz; a steep spectrum at low frequencies (a spectral index, α = -1.10 ± 0.03) changes at ˜10 GHz into an inverted spectrum at higher frequencies (α = +0.86 ± 0.09). We conduct new observations at 15-43 GHz using the Very Large Array and at 100 GHz using the Nobeyama Millimeter Array. As a result, the high-frequency excess has been confirmed as continuing at even higher radio frequencies, up to 43 GHz. The non-detection at 100 GHz was not so strong a constraint, and therefore the spectral behavior above 43 GHz remains unclear. The astrometric position of the high-frequency excess component coincides with the optical position of the Seyfert nucleus and the low-frequency radio position to an accuracy of 0{^''.}1, corresponding to ˜80 pc; the radio source size is constrained to be <0{^''.}02, corresponding to <16 pc. We discuss the physical origin of the observed high-frequency excess component. Dust emission at the Rayleigh-Jeans regime, free-free emission from X-ray radiating high-temperature plasma, free-free emission from the ensemble of broad-line region clouds, or thermal synchrotron from hot accretion flow cannot be responsible for the observed radio flux. Compact jets under synchrotron self-absorption may be unlikely in terms of observed time scales. Alternatively, we cannot rule out the hypotheses of synchrotron jets free-free absorbed by a circumnuclear photo-ionized region, and self-absorbed nonthermal synchrotron from disk corona, as the origin of the high-frequency excess component.

  16. RX J1301.9+2747: A HIGHLY VARIABLE SEYFERT GALAXY WITH EXTREMELY SOFT X-RAY EMISSION

    SciTech Connect

    Sun Luming; Shu Xinwen; Wang Tinggui E-mail: xwshu@mail.ustc.edu.cn

    2013-05-10

    In this paper we present a temporal and spectral analysis of X-ray data from XMM-Newton and Chandra observations of the ultrasoft and variable Seyfert galaxy RX J1301.9+2747. In both observations the source clearly displays two distinct states in the X-ray band: a long quiescent state and a short flare (or eruptive) state which differs in count rates by a factor of 5-7. The transition from the quiescent to the flare state occurs in 1-2 ks. We have observed that the quiescent state spectrum is unprecedentedly steep with a photon index {Gamma} {approx} 7.1, and the spectrum of the flare state is flatter with {Gamma} {approx} 4.4. X-rays above 2 keV were not significantly detected in either state. In the quiescent state, the spectrum appears to be dominated by a blackbody component of temperature about {approx}30-40 eV, which is comparable to the expected maximum effective temperature from the inner accretion disk. The quiescent state, however, requires an additional steep power law, presumably arising from Comptonization by transient heated electrons. The optical spectrum from the Sloan Digital Sky Survey shows Seyfert-like narrow lines for RX J1301.9+2747, while Hubble Space Telescope imaging reveals a central point source for the object. In order to precisely determine the hard X-ray component, future longer X-ray observations are required. This will help constrain the accretion disk model for RX J1301.9+2747, and shed new light on the characteristics of the corona and accretion flows around black holes.

  17. The gamma-ray emitting radio-loud narrow-line Seyfert 1 galaxy PKS 2004-447. I. The X-ray View

    NASA Astrophysics Data System (ADS)

    Kreikenbohm, A.; Schulz, R.; Kadler, M.; Wilms, J.; Markowitz, A.; Chang, C. S.; Carpenter, B.; Elsässer, D.; Gehrels, N.; Mannheim, K.; Müller, C.; Ojha, R.; Ros, E.; Trüstedt, J.

    2016-01-01

    As part of the TANAMI multiwavelength progam, we discuss new X-ray observations of the γ-ray and radio-loud narrow line Seyfert 1 galaxy (γ-NLS1) PKS 2004-447. The active galaxy is a member of a small sample of radio-loud NLS1s detected in γ-rays by the Fermi Large Area Telescope. It stands out for being the radio-loudest and the only southern-hemisphere source in this sample. We present results from our X-ray monitoring program comprised of Swift snapshot observations from 2012 through 2014 and two new X-ray observations with XMM-Newton in 2012. Supplemented by archival data from 2004 and 2011, our data set allows for a careful analysis of the X-ray spectrum and variability of this peculiar source. The (0.5-10) keV spectrum is described well by a power law (Γ ~ 1.6), which can be interpreted as non-thermal emission from a relativistic jet. The source exhibits moderate flux variability on timescales of both months and years. Correlated brightness variations in the (0.5-2) keV and (2-10) keV bands are explained by a single variable spectral component, such as the one from the jet. A possible soft excess seen in the data from 2004 cannot be confirmed by the new XMM-Newton observations taken during low-flux states. Any contribution to the total flux in 2004 is less than 20% of the power-law component. The (0.5-10) keV luminosities of PKS 2004-447 are in the range of (0.5-2.7) × 1044 erg s-1. A comparison of the X-ray properties among the known γ-NLS1 galaxies shows that in four out of five cases the X-ray spectrum is dominated by a flat power law without intrinsic absorption. These objects are moderately variable in their brightness, while spectral variability is observed in at least two sources. The major difference across the X-ray spectra of γ-NLS1s is the luminosity, which spans a range of almost two orders of magnitude from 1044 erg s-1 to 1046 erg s-1 in the (0.5-10) keV band.

  18. Radio-to-γ-ray monitoring of the narrow-line Seyfert 1 galaxy PMN J0948 + 0022 from 2008 to 2011

    NASA Astrophysics Data System (ADS)

    Foschini, L.; Angelakis, E.; Fuhrmann, L.; Ghisellini, G.; Hovatta, T.; Lahteenmaki, A.; Lister, M. L.; Braito, V.; Gallo, L.; Hamilton, T. S.; Kino, M.; Komossa, S.; Pushkarev, A. B.; Thompson, D. J.; Tibolla, O.; Tramacere, A.; Carramiñana, A.; Carrasco, L.; Falcone, A.; Giroletti, M.; Grupe, D.; Kovalev, Y. Y.; Krichbaum, T. P.; Max-Moerbeck, W.; Nestoras, I.; Pearson, T. J.; Porras, A.; Readhead, A. C. S.; Recillas, E.; Richards, J. L.; Riquelme, D.; Sievers, A.; Tammi, J.; Tornikoski, M.; Ungerechts, H.; Zensus, J. A.; Celotti, A.; Bonnoli, G.; Doi, A.; Maraschi, L.; Tagliaferri, G.; Tavecchio, F.

    2012-12-01

    We present more than three years of observations at different frequencies, from radio to high-energy γ-rays, of the Narrow-Line Seyfert 1 (NLS1) Galaxy PMN J0948 + 0022 (z = 0.585). This source is the first NLS1 detected at energies above 100 MeV and therefore can be considered the prototype of this emerging new class of γ-ray emitting active galactic nuclei (AGN). The observations performed from 2008 August 1 to 2011 December 31 confirmed that PMN J0948 + 0022 generates a powerful relativistic jet, which is able to develop an isotropic luminosity at γ-rays of the order of 1048 erg s-1, at the level ofpowerful quasars. The evolution of the radiation emission of this source in 2009 and 2010 followed the canonical expectations of relativistic jets with correlated multiwavelength variability (γ-rays followed by radio emission after a few months), but it was difficult to retrieve a similar pattern in the light curves of 2011. The comparison of γ-ray spectra before and including 2011 data suggested that there was a softening of the high-energy spectral slope. We selected five specific epochs to be studied by modelling the broad-band spectrum, which are characterised by an outburst at γ-rays or very low/high flux at other wavelengths. The observed variability can largely be explained by changes in the injected power, the bulk Lorentz factor of the jet, or the electron spectrum. The characteristic time scale of doubling/halving flux ranges from a few days to a few months, depending on the frequency and the sampling rate. The shortest doubling time scale at γ-rays is 2.3 ± 0.5 days. These small values underline the need of highly sampled multiwavelength campaigns to better understand the physics of these sources. Appendix A is available in electronic form at http://www.aanda.orgData displayed in Figs. A.1-A.3 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc

  19. Spectral Anomalies in the 11 and 12 micron Region From the Mariner Mars 7 Infrared Spectrometer

    NASA Technical Reports Server (NTRS)

    Kirkland, Laurel E.; Herr, Kenneth C.

    2000-01-01

    Two hundred-forty infrared spectra acquired by the 1969 Mariner Mars 7 Infrared Spectrometer (IRS), spanning the wavelength region 1.8-14.4 micron (5550-690/cm), have recently been recovered and calibrated in both wavelength and intensity. An examination of these IRS spectra has revealed absorptions at 11.25 and 12.5 micron that have not previously been reported for Mars. A search of the literature and spectral data bases shows that materials that exhibit a doublet at 11.25 and 12.5 micron are rare. In this paper we examine potential causes for these features and include a detailed discussion of carbonates, goethite, CO2 ice, and water ice. CO2 ice and water ice measured in transmission do not exhibit bands that match those recorded at 11.25 and 12.5 micron for Mars, which indicates that CO2 or water ice clouds are not the source of these features. Since these bands show no clear correlation with atmospheric path length, they are most likely caused by a surface material. In the IRS database they appear to be exceptionally intense in the western part of the Hellas basin. Goethite exhibits bands that are a good spectral match, but confirming whether goethite causes the features will require additional studies of the 20-50 micron region. These studies will require laboratory measurements of weathering coatings and an examination of spectra recorded of Mars by the 1971 Mariner Mars Infrared Interferometer Spectrometer (IRIS; 5-50 micron 2000200/cm) and the 1996 Thermal Emission Spectrometer (TES; 6-50 micron 1667-200/cm).

  20. High-resolution study of luminous infrared galaxies. I - The composite nature of the Seyfert 1 galaxy IRAS 20044-6114 (NGC 6860)

    NASA Technical Reports Server (NTRS)

    Lipari, Sebastian; Tsvetanov, Zlatan; Macchetto, F.

    1993-01-01

    The physical conditions in the ionized gas, the stellar population, and the kinematics of the Seyfert 1 galaxy IRAS 20044-6114 (NGC 6860) are studied by high spatial resolution optical imaging and optical and near-IR spectroscopy of this luminous IR source. The broadband images show a compact nucleus, two weak spiral arms, a bar, a bulge, an inner ring, and a possible outer ring. The I-alpha image reveals bright emission-line regions associated with the Seyfert nucleus and an inner ring of intense star formation. The forbidden O III 5007-A image shows that the high-excitation gas is elongated perpendicularly to the direction of the bar, and reveals a bright compact object at about 40 arcsec NE of the nucleus which is undetectable in the broadband images. This object is interpreted as a dwarf young H II galaxy. The optical, near-IR, and FIR results show clear evidence that the nuclear and circumnuclear regions have composite and complex structure: a variable Seyfert 1 nucleus embedded in an intense and dusty star formation. environment.

  1. PROBING THE PHYSICS OF NARROW LINE REGIONS IN ACTIVE GALAXIES. II. THE SIDING SPRING SOUTHERN SEYFERT SPECTROSCOPIC SNAPSHOT SURVEY (S7)

    SciTech Connect

    Dopita, Michael A.; Davies, Rebecca; Kewley, Lisa; Hampton, Elise; Sutherland, Ralph; Shastri, Prajval; Kharb, Preeti; Jose, Jessy; Bhatt, Harish; Ramya, S.; Scharwächter, Julia; Jin, Chichuan; Banfield, Julie; Zaw, Ingyin; Juneau, Stéphanie; Srivastava, Shweta

    2015-03-15

    Here we describe the Siding Spring Southern Seyfert Spectroscopic Snapshot Survey (S7) and present results on 64 galaxies drawn from the first data release. The S7 uses the Wide Field Spectrograph mounted on the ANU 2.3 m telescope located at the Siding Spring Observatory to deliver an integral field of 38 × 25 arcsec at a spectral resolution of R = 7000 in the red (530–710 nm), and R = 3000 in the blue (340–560 nm). From these data cubes we have extracted the narrow-line region spectra from a 4 arcsec aperture centered on the nucleus. We also determine the Hβ and [O iii] λ5007 fluxes in the narrow lines, the nuclear reddening, the reddening-corrected relative intensities of the observed emission lines, and the Hβ and [O iii] λ5007 luminosities determined from spectra for which the stellar continuum has been removed. We present a set of images of the galaxies in [O iii] λ5007, [N ii] λ6584, and Hα, which serve to delineate the spatial extent of the extended narrow-line region and also to reveal the structure and morphology of the surrounding H ii regions. Finally, we provide a preliminary discussion of those Seyfert 1 and Seyfert 2 galaxies that display coronal emission lines in order to explore the origin of these lines.

  2. Structure of the Circumnuclear Region of Seyfert 2 Galaxies Revealed by RXTE Hard X-Ray Observations of NGC 4945

    NASA Technical Reports Server (NTRS)

    Madejski, G.; Zycki, P.; Done, C.; Valinia, A.; Blanco, P.; Rothschild, R.; Turek, B.

    2000-01-01

    NGC 4945 is one of the brightest Se.yfert galaxies on the sky at 100 keV, but is completely absorbed below 10 keV, implying an optical depth of the absorber to electron scattering of a few; its absorption column is probably the largest which still allows a direct view of the nucleus at hard X-ray energies. Our observations of it with the Rossi X-ray Timing Explorer (RXTE) satellite confirm the large absorption, which for a simple phenomenological fit using an absorber with Solar abundances implies a column of 4.5(sup 0.4, sub -0.4) x 10(exp 24) /sq cm. Using a a more realistic scenario (requiring Monte Carlo modeling of the scattering), we infer the optical depth to Thomson scattering of approximately 2.4. If such a scattering medium were to subtend a large solid angle from the nucleus, it should smear out any intrinsic hard X-ray variability on time scales shorter than the light travel time through it. The rapid (with a time scale of approximately a day) hard X-ray variability of NGC 4945 we observed with the RXTE implies that the bulk of the extreme absorption in this object does not originate in a parsec-size, geometrically thick molecular torus. Limits on the amount of scattered flux require that the optically thick material on parsec scales must be rather geometrically thin, subtending a half-angle < 10 deg. This is only marginally consistent with the recent determinations of the obscuring column in hard X-rays, where only a quarter of Seyfert 2s have columns which are optically thick, and presents a problem in accounting for the Cosmic X-ray Background primarily with AGN possessing the geometry as that inferred by us. The small solid angle of the obscuring material, together with the black hole mass (of approximately 1.4 x 10(exp 6) solar mass) from megamaser measurements. allows a robust determination of the source luminosity, which in turn implies that the source radiates at approximately 10% of the Eddington limit.

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

    NASA Astrophysics Data System (ADS)

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

    2016-06-01

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

  4. Multi-wavelength observations of the narrow-line Seyfert 1 galaxy RX J2314.9+2243

    NASA Astrophysics Data System (ADS)

    Komossa, S.; Myserlis, I.; Fuhrmann, L.; Xu, D.; Grupe, D.; Fan, Z.; Yao, S.; Angelakis, E.; Karamanavis, V.; Zensus, J. A.; Yuan, W.

    2016-02-01

    Narrow-line Seyfert 1 (NLS1) galaxies are a sub-class of active galactic nuclei (AGN) with relatively low-mass black holes, accreting near the Eddington rate. A small fraction of them is radio-loud and harbors relativistic jets. As a class, these provide us with new insights into the cause(s) of radio-loudness, the blazar phenomenon at low black hole masses, and the operation of radio-mode feedback. The NLS1 galaxy RXJ2314.9+2243 is remarkable for its multi-wavelength properties. We present new radio observations taken at Effelsberg, and a summary of the recent results from our multi-wavelength study. RXJ2314.9+2243 is radio-loud, luminous in the infrared, has a flat X-ray spectrum and peculiar UV spectrum, and hosts an exceptionally broad and blueshifted [OIII]λ5007 emission line, indicating the presence of a strong outflow. RXJ2314.9+2243 likely represents an extreme case of AGN induced feedback in the local universe.

  5. The extreme behavior of the radio-loud narrow-line Seyfert 1 galaxy J0849+5108

    SciTech Connect

    Maune, Jeremy D.; Eggen, Joseph R.; Miller, H. Richard; Marshall, Kevin; Readhead, Anthony C. S.; Hovatta, Talvikki; King, Oliver

    2014-10-10

    Simultaneous radio, optical (both photometry and polarimetry), X-ray, and γ-ray observations of the radio-loud narrow-line Seyfert 1 (RL-NLSy1) galaxy J0849+5108 are presented. A massive three-magnitude optical flare across five nights in 2013 April is detected, along with associated flux increases in the γ-ray, infrared, and radio regimes; no comparable event was detected in the X-rays, though this may be due to poor coverage. A spectral energy distribution (SED) for the object using quasi-simultaneous data centered on the optical flare is compared to the previously published SEDs for the object by D'Ammando et al. The flare event coincided with a high degree of optical polarization. High amplitude optical microvariability is clearly detected, and is found to be of comparable amplitude when the object is observed in both faint and bright states. The object is also seen to undergo rapid shifts in polarization in both degree and electric vector position angle within a single night. J0849+5108 appears to show even more extreme variability than that previously reported for the similar object J0948+0022. These observations appear to support the growing claim that some RL-NLSy1 galaxies constitute a sub-class of blazar-like active galactic nuclei.

  6. Distribution of Molecules in the Circumnuclear Disk and Surrounding Starburst Ring in the Seyfert Galaxy NGC 1068 Observed with ALMA

    NASA Astrophysics Data System (ADS)

    Takano, S.; Nakajima, T.; Kohno, K.; Harada, N.; Herbst, E.; Tamura, Y.; Izumi, T.; Taniguchi, A.; Tosaki, T.

    2015-12-01

    We report distributions of several molecular transitions including shock and dust related species (13CO and C18O J = 1-0, 13CN N = 1-0, CS J = 2-1, SO JN = 32-21, HNCO JKa,Kc = 50,5-40,4, HC3N J = 11-10, 12-11, CH3OH JK = 2K-1K, and CH3CN JK = 6K-5K) in the nearby Seyfert 2 galaxy NGC 1068 observed with ALMA. The central ˜1' (˜4.3 kpc) of this galaxy was observed in the 100 GHz region with an angular resolution of ˜4" x 2" (290 pc x 140 pc) to study the effects of an active galactic nucleus and its surrounding starburst ring on molecular abundances. We report a classification of molecular distributions into three main categories. Organic molecules such as CH3CN are found to be concentrated in the circumnuclear disk. In the starburst ring, the intensity of methanol at each clumpy region is not consistent with that of 13CO.

  7. Physical conditions in the x-ray emission-line gas in the Seyfert 2 galaxy NGC 1068

    NASA Astrophysics Data System (ADS)

    Sharma, Neetika

    Active Galactic Nuclei (AGN) reside in the centers of many (10%) galaxies. The nuclear spectra exhibit a broad (from radio to gamma-rays) non-stellar continuum which exceeds the luminosity of the host. AGN are thought to be powered by accretion of matter onto a supermassive black hole (BH~10 6--109 times the mass of the Sun). Since this activity takes place in a relatively small region (<< 3 light years), the central engine of even the closest AGN cannot be imaged directly with current technology. Nevertheless, spectroscopic observations can help us constrain the conditions of the gas very close to the BH. The scientific goal of my thesis is to examine the physical conditions in the circumnuclear regions of the Seyfert 2 galaxy NGC 1068. The soft X-ray spectrum comprises a multitude of emission lines including those of C, N, O, Ne, Mg, that arise in gas that is spatially extended over ~1000 light years. Radiative recombination continuum widths indicate the gas is photoionized and I model it finding a two-zone solution with unusual abundances attributed to the star formation history of the galaxy. Also of interest are the Fe K complex of em.

  8. A Cutoff in the X-Ray Fluctuation Power Density Spectrum of the Seyfert 1 Galaxy NGC 3516

    NASA Technical Reports Server (NTRS)

    Edelson, Rick; Nandra, Kirpal

    1999-01-01

    During 1997 March-July, RXTE observed the bright, strongly variable Seyfert 1 galaxy NGC 3516 once every approx. 12.8 hr for 4.5 months and nearly continuously (with interruptions due to SAA passage but not Earth occultation) for a 4.2 day period in the middle. These were followed by ongoing monitoring once every approx. 4.3 days. These data are used to construct the first well-determined X-ray fluctuation power density spectrum (PDS) of an active galaxy to span more than 4 decades of usable temporal frequency. The PDS shows no signs of any strict or quasi-periodicity, but does show a progressive flattening of the power-low slope from -1.74 at short time scales to -0.73 at longer time scales. This is the clearest observation to date of the long-predicted cutoff in the PDS. The characteristic variability time scale corresponding to this cutoff temporal frequency is approx. 1 month. Although it is unclear how this time scale may be interpreted in terms of a physical size or process, there are several promising candidate models. The PDS appears similar to those seen for Galactic black hole candidates such as Cyg X-1, suggesting that these two classes of objects with very different luminosities and putative black hole masses (differing by more than a factor of 10(exp 5)) may have similar X-ray generation processes and structures.

  9. A long XMM-Newton observation of an extreme narrow-line Seyfert 1: PG 1244+026

    NASA Astrophysics Data System (ADS)

    Jin, Chichuan; Done, Chris; Middleton, Matthew; Ward, Martin

    2013-12-01

    We explore the origin of the strong soft X-ray excess in narrow-line Seyfert 1 galaxies using spectral-timing information from a 120 ks XMM-Newton observation of PG 1244+026. Spectral fitting alone cannot distinguish between a true additional soft X-ray continuum component and strongly relativistically smeared reflection, but both models also require a separate soft blackbody component. This is most likely intrinsic emission from the disc extending into the lowest energy X-ray bandpass. The rms spectra on short time-scales (200-5000 s) contain both (non-disc) soft excess and power-law emission. However, the spectrum of the variability on these time-scales correlated with the 4-10 keV light curve contains only the power law. Together these show that there is fast variability of the soft excess which is independent of the 4-10 keV variability. This is inconsistent with a single reflection component making the soft X-ray excess as this necessarily produces correlated variability in the 4-10 keV bandpass. Instead, the rms and covariance spectra are consistent with an additional cool Comptonization component which does not contribute to the spectrum above 2 keV.

  10. Zooming in on the peculiar radio-loud narrow-line Seyfert 1 galaxy, J1100+4421

    NASA Astrophysics Data System (ADS)

    Gabányu, K. É.; Frey, S.; Paragi, Z.; Tar, I.; An, T.; Tanaka, M.; Morokuma, T.

    2016-08-01

    Narrow-line Seyfert 1 galaxies (NLS1) are interesting subsamples of active galactic nuclei, which are typically thought to contain a relatively smaller supermassive black holes (10^6-10^8 solar masses) and show quite high accretion rate. Only 7% of them are detected in radio. The radio structure of the objects in the extremely radio-loud NLS1 subsample indicates the presence of relativistically beamed jets. Some radio-loud NLS1s were detected even at high energies with the Fermi Large Array Telescope. Therefore these sources are often suggested to be the low-luminosity and younger counterparts of blazars. SDSS J110006.07+442144.3 was identified as an NLS1 at z=0.84 after its dramatic optical brightening discovered by Tanaka et al. (2014) Our dual-frequency (1.6 and 5 GHz) European VLBI Network observations taken one year after this event show a compact structre with brightness temperature of 6 x 10^9 K and a flat spectral index indicating the presence of a compact synchrotron self-absorbed core. Compared with low resolution VLA-FIRST data, the large-scale structure seen there is resolved out in the EVN observation. However the recovered flux density in our L-band EVN observation is significantly higher than the FIRST flux density, which is indicative of brightening in the radio regime. All these results fit into the picture where radio-loud NLS1s are described as faint blazars.

  11. A SEYFERT-2-LIKE SPECTRUM IN THE HIGH-MASS X-RAY BINARY MICROQUASAR V4641 SGR

    SciTech Connect

    Morningstar, Warren R.; Miller, Jon M.; Reynolds, M. T.; Maitra, Dipankar E-mail: jonmm@umich.edu

    2014-05-10

    We present an analysis of three archival Chandra observations of the black hole V4641 Sgr, performed during a decline into quiescence. The last two observations in the sequence can be modeled with a simple power law. The first spectrum, however, is remarkably similar to spectra observed in Seyfert-2 active galactic nuclei, which arise through a combination of obscuration and reflection from distant material. This spectrum of V4641 Sgr can be fit extremely well with a model including partial-covering absorption and distant reflection. This model recovers a Γ ≅ 2.0 power-law incident spectrum, typical of black holes at low Eddington fractions. The implied geometry is plausible in a high-mass X-ray binary like V4641 Sgr, and may be as compelling as explanations invoking Doppler-split line pairs in a jet, and/or unusual Comptonization. We discuss potential implications and means of testing these models.

  12. THE BLACK HOLE SPIN AND SOFT X-RAY EXCESS OF THE LUMINOUS SEYFERT GALAXY FAIRALL 9

    SciTech Connect

    Lohfink, Anne M.; Reynolds, Christopher S.; Mushotzky, Richard F.; Miller, Jon M.; Brenneman, Laura W.; Nowak, Michael A.; Fabian, Andrew C.

    2012-10-10

    We present an analysis of all XMM-Newton and Suzaku X-ray spectra of the nearby luminous Seyfert galaxy Fairall 9. Confirming previous analyses, we find robust evidence for a broad iron line associated with X-ray reflection from the innermost accretion disk. By fitting a spectral model that includes a relativistically ionized reflection component, we examine the constraints on the inclination of the inner accretion disk and the black hole spin, and the complications introduced by the presence of a photoionized emission line system. Employing multi-epoch fitting, we attempt to obtain robust and concordant measures of the accretion disk parameters. We also clearly see a soft X-ray excess in Fairall 9. During certain epochs, the soft excess can be described with the same disk reflection component that produces the iron line. However, there are epochs where an additional soft component is required. This can be attributed to either an additional highly ionized, strongly blurred disk reflection component or a new X-ray continuum component.

  13. Radio-loud Narrow Line Seyfert 1 under a different perspective: a revised black hole mass estimate from optical spectropolarimetry

    NASA Astrophysics Data System (ADS)

    Baldi, Ranieri D.; Capetti, Alessandro; Robinson, Andrew; Laor, Ari; Behar, Ehud

    2016-05-01

    Several studies indicate that radio-loud (RL) active galactic nuclei (AGNs) are produced only by the most massive black holes (BH), MBH ˜ 108-1010 M⊙. This idea has been challenged by the discovery of RL Narrow Line Seyfert 1 (RL NLSy1), having estimated masses of MBH ˜ 106-107 M⊙. However, these low MBH estimates might be due to projection effects. Spectropolarimetry allows us to test this possibility by looking at RL NLSy1s under a different perspective, i.e. from the viewing angle of the scattering material. We here report the results of a pilot study of Very Large Telescope spectropolarimetric observations of the RL NLSy1 PKS 2004-447. Its polarization properties are remarkably well reproduced by models in which the scattering occurs in an equatorial structure surrounding its broad-line region, seen close to face-on. In particular, we detect a polarized Hα line with a width of ˜9000 km s-1, ˜6 times broader than the width seen in direct light. This corresponds to a revised estimate of MBH ˜ 6 × 108 M⊙, well within the typical range of RL AGN. The double-peaked polarized broad Hα profile of the target suggests that the rare combination of the orientation effects and a broad line region dominated by the rotation might account for this class of objects, casting doubts on the virial estimates of BH mass for type-I AGN.

  14. The host galaxy of the gamma-ray narrow-line Seyfert 1 galaxy 1H 0323+342

    SciTech Connect

    León Tavares, J.; Chavushyan, V.; Puerari, I.; Patiño-Alvarez, V.; Carramiñana, A.; Carrasco, L.; Guichard, J.; Olguín-Iglesias, A.; Valdes, J.; Kotilainen, J.; Añorve, C.; Antón, S.; Karhunen, K.; Sanghvi, J.

    2014-11-01

    We present optical and near-infrared (NIR) imaging data of the radio-loud, narrow-line Seyfert 1 galaxy 1H 0323+342, which shows intense and variable gamma-ray activity discovered by the Fermi satellite with the Large Area Telescope. Near-infrared and optical images are used to investigate the structural properties of the host galaxy of 1H 0323+342; this together with optical spectroscopy allows us to examine its black hole mass. Based on two-dimensional (2D) multiwavelength surface-brightness modeling, we find that statistically, the best model fit is a combination of a nuclear component and a Sérsic profile (n ∼ 2.8). However, the presence of a disk component (with a small bulge n ∼ 1.2) also remains a possibility and cannot be ruled out with the present data. Although at first glance a spiral-arm-like structure is revealed in our images, a 2D Fourier analysis of the imagery suggests that this structure corresponds to an asymmetric ring, likely associated with a recent violent dynamical interaction. We discuss our results in the context of relativistic jet production and galaxy evolution.

  15. X-ray Variability of the Magnetic Cataclysmic Variable V1432 Aql and the Seyfert Galaxy NGC 6814

    NASA Technical Reports Server (NTRS)

    Mukai, K.; Hellier, C.; Madejski, G.; Patterson, J.; Skillman, D. R.

    2003-01-01

    V1432 Aquilae (=RX J1940.2-1025) is the X-ray bright, eclipsing magnetic cataclysmic variable approximately 37 (sup) away from the Seyfert galaxy, NGC 6814. Due to a 0.3% difference between the orbital (12116.3 s) and the spin (12150 s) periods: the accretion geometry changes over the approximately 50 day beat period. Here we report the results of an RXTE campaign to observe the eclipse 25 times, as well as of archival observations with ASCA and BeppoSAX. Having confirmed that the eclipse is indeed caused by the secondary, we use the eclipse timings and profiles to map the accretion geometry as a function of the beat phase. We find that the accretion region is compact, and that it moves relative to the center of white dwarf on the beat period. The amplitude of this movement suggest a low-mass white dwarf, in contrast to the high mass previously estimated from its X-ray spectrum. The size of the X-ray emission region appears to be larger than in other eclipsing magnetic CVs. We also report on the RXTE data as well as the long-term behavior of NGC 6814, indicating flux variability by a factor of at least 10 on time scales of years.

  16. Monitoring the Violent Activity from the Inner Accretion Disk of the Seyfert 1.9 Galaxy NGC 2992 with RXTE

    NASA Technical Reports Server (NTRS)

    Mruphy, Kendrah D.; Yaqoob, Tahir; Terashima, Yuichi

    2007-01-01

    We present the results of a one year monitoring campaign of the Seyfert 1.9 galaxy NGC 2992 with RXTE. Historically, the source has been shown to vary dramatically in 2-10 keV flux over timescales of years and was thought to be slowly transitioning between periods of quiescence and active accretion. Our results show that in one year the source continuum flux covered almost the entire historical range, making it unlikely that the low-luminosity states correspond to the accretion mechanism switching off. During flaring episodes we found that a highly redshifted Fe K line appears, implying that the violent activity is occurring in the inner accretion disk, within 100 gravitational radii of the central black hole. We also found that the Compton y parameter for the X-ray continuum remained approximately constant during the large amplitude variability. These observations make NGC 2992 well-suited for future multi-waveband monitoring, as a test-bed for constraining accretion models.

  17. X-RAY DIPS IN THE SEYFERT GALAXY FAIRALL 9: COMPTON-THICK 'COMETS' OR A FAILED RADIO GALAXY?

    SciTech Connect

    Lohfink, Anne M.; Reynolds, Christopher S.; Mushotzky, Richard F.; Wilms, Joern

    2012-04-20

    We investigate the spectral variability of the Seyfert galaxy Fairall 9 using almost 6 years of monitoring with the Rossi X-ray Timing Explorer with an approximate time resolution of 4 days. We discover the existence of pronounced and sharp dips in the X-ray flux, with a rapid decline of the 2-20 keV flux of a factor of two or more followed by a recovery to pre-dip fluxes after {approx}10 days. These dips skew the flux distribution away from the commonly observed lognormal distribution. Dips may result from the eclipse of the central X-ray source by broad-line region clouds, as has recently been found in NGC 1365 and Mrk 766. Unlike these other examples, however, the clouds in Fairall 9 would need to be Compton-thick, and the non-dip state is remarkably free of any absorption features. A particularly intriguing alternative is that the accretion disk is undergoing the same cycle of disruption/ejection as seen in the accretion disks of broad-line radio galaxies such as 3C120 but, for some reason, fails to create a relativistic jet. This suggests that a detailed comparison of Fairall 9 and 3C120 with future high-quality data may hold the key to understanding the formation of relativistic jets in active galactic nucleus.

  18. Resolving the Large Scale Spectral Variability of the Luminous Seyfert 1 Galaxy 1H 0419-577

    NASA Technical Reports Server (NTRS)

    Pounds, K. A.; Reeves, J. N.; Page, K. L.; OBrien, P. T.

    2004-01-01

    An XMM-Newton observation of the luminous Seyfert 1 galaxy 1H 0419-577 in September 2002, when the source was in an extreme low-flux state, found a very hard X-ray spectrum at 1-10 keV with a strong soft excess below approximately 1 keV. Comparison with an earlier XMM-Newton observation when 1H 0419-577 was X-ray bright indicated the dominant spectral variability was due to a steep power law or cool Comptonized thermal emission. Four further XMM-Newton observations, with 1H 0419-577 in intermediate flux states, now support that conclusion, while we also find the variable emission component in intermediate state difference spectra to be strongly modified by absorption in low ionisation matter. The variable soft excess is seen to be an artefact of absorption of the underlying continuum while the core soft emission is attributed to recombination in an extended region of more highly ionised gas. This new analysis underlines the importance of fully accounting for absorption in characterizing AGN X-ray spectra.

  19. Exceptional behaviour of X-ray emitting corona in a Seyfert 1 galaxy 1H 0419 - 577

    NASA Astrophysics Data System (ADS)

    Pal, Main; Dewangan, Gulab Chand

    2016-07-01

    We report on six XMM-Newton observations of a Seyfert 1 galaxy 1H 0419-577 during spectacular behaviour of the corona about on 2-3 months time scale. The source reflects similar trend in each energy band from Optical/UV to X-rays during 2002-2003. The Optical/UV emission varies from trough to peak by 4.2-22.1% and peak to trough by 6.6-10.3%. At the same time, the 2 - 10keV powerlaw emission is strongly correlated with soft X-ray excess with similar fractional variability amplitude ˜ 40% suggesting variation in coronal geometry. We also found that the height of X-ray source remains almost similar about 2rg (gravitaional radius) for each observation. This indicates clearly that source size is changing dramatically. Further, the powerlaw emission and Optical/UV emission seem correlated to each other. The observed variation in Optical/UV emission further support the variable size of corona. During incraesing trend of Optical/UV to X-rays, the X-ray source expands horizontally and while decreasing the X-ray source seems to shrink. This is supported by the observed more variation in Optical emission compared to UV emission while decreasing in flux from peak to trough.

  20. The Einstein observatory medium sensitivity survey - The quasars sample

    NASA Technical Reports Server (NTRS)

    Gioia, I. M.; Maccacaro, T.

    1983-01-01

    A complete sample of X-ray-selected quasars and Seyfert galaxies extracted from the Einstein Observatory Medium Sensitivity Survey is described, and their physical characteristics are discussed. A Hubble constant of 50 km/s per Mpc and a Friedmann universe with a deceleration parameter of q(0)=0 are assumed throughout the survey, and the sample of X-ray sources was selected according to the following criteria: the significance of the detection exceeds a confidence level of 5 beta; the source is physically unrelated to the target of the IPC observation; and that the source is at a galactic latitude higher than 20 deg. The redshift and optical luminosity distributions of 55 Active Galactic Nuclei (AGNs) detected in the survey are discussed. A number flux relation for the different classes of extragalactic objects are analyzed in detail, using a Maximum Likelihood method and the assumption that the relation can be represented as a power law.

  1. The broad-band X-ray spectrum of a QSO sample

    NASA Technical Reports Server (NTRS)

    Worrall, D. M.; Marshall, F. E.

    1983-01-01

    A sample of 25 QSOs was used to investigate the average spectrum between the soft X-ray energy band of the Einstein Observatory image proportional counter, and the higher energy band of the HEAO 1 A2 experiment. The spectrum is similar to thoe exhibited by Seyfert galaxies and narrow emission line galaxies above 2 keV. The spectrum is soft enough that if these objects are typical of the higher redshift, more radio-quiet QSOs, then it is possible to exclude QSOs as being the dominant origin of the diffuse X-ray background.

  2. FUSE Observations of Galactic and Intrinsic Absorption in the Spectrum of the Seyfert 1 Galaxy 2MASX J21362313-6224008

    NASA Technical Reports Server (NTRS)

    Bonamente, Massimiliano; Dixon, W. Van Dyke

    2004-01-01

    We present the far-ultraviolet spectrum of the Seyfert 1 galaxy 2MASX J21362313-6224008 obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE). The spectrum features absorption from Galactic O VI at two velocities and redshifted H I Ly beta and gamma, C II, CIII, and O VI. The redshifted absorption features represent a single kinematic component blueshifted by approx. 310 km/s relative to the active galactic nucleus. We use photoionization models to derive constraints on the physical parameters of the absorbing gas. An alternative interpretation for the absorption lines is also proposed, wherein the absorbing gas is associated with an intervening galaxy cluster.

  3. FUSE Detection of Galactic and Intrinsic Absorption in the Spectrum of the Seyfert 1 Galaxy 2MASX J21362313-6224008

    NASA Technical Reports Server (NTRS)

    Bonamente, Massimiliano; VanDykeDixon, W.

    2003-01-01

    We present the far-ultraviolet spectrum of the Seyfert 1 galaxy 2MASX 521362313-6224008 obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE). The spectrum features absorption from Galactic O VI at two velocities and redshifted H I Lyman beta and gamma, C II, C III, and O VI. The redshifted absorption features represent a single kinematic component blueshifted by approx. 310 km/s relative to the AGN. We use photoionization models to derive the physical parameters of the absorbing gas. An alternative interpretation for the absorption lines is also proposed, whereby the absorbing gas is associated with an intervening galaxy cluster.

  4. The Complex Gas Kinematics in the Nucleus of the Seyfert 2 Galaxy NGC 1386: Rotation, Outflows, and Inflows

    NASA Astrophysics Data System (ADS)

    Lena, D.; Robinson, A.; Storchi-Bergman, T.; Schnorr-Müller, A.; Seelig, T.; Riffel, R. A.; Nagar, N. M.; Couto, G. S.; Shadler, L.

    2015-06-01

    We present optical integral field spectroscopy of the circum-nuclear gas of the Seyfert 2 galaxy NGC 1386. The data cover the central 7″ × 9″ (530 × 680 pc) at a spatial resolution of 0.″ 9 (68 pc), and the spectral range 5700-7000 Å at a resolution of 66 km s-1. The line emission is dominated by a bright central component, with two lobes extending ≈3″ north and south of the nucleus. We identify three main kinematic components. The first has low velocity dispersion (\\bar{σ } ≈ 90 km s-1), extends over the whole field of view, and has a velocity field consistent with gas rotating in the galaxy disk. We interpret the lobes as resulting from photoionization of disk gas in regions where the active galactic nucleus radiation cones intercept the disk. The second has higher velocity dispersion (\\bar{σ } ≈ 200 km s-1) and is observed in the inner 150 pc around the continuum peak. This component is double peaked, with redshifted and blueshifted components separated by ≈500 km s-1. Together with previous Hubble Space Telescope imaging, these features suggest the presence of a bipolar outflow for which we estimate a mass outflow rate of \\dot{M} ≳ 0.1 {{M}⊙ } yr-1. The third component is revealed by velocity residuals associated with enhanced velocity dispersion and suggests that outflow and/or rotation is occurring approximately in the equatorial plane of the torus. A second system of velocity residuals may indicate the presence of streaming motions along dusty spirals in the disk.

  5. ROSAT and ASCA Observations of the Seyfert Galaxy 1H0419-577, Identified with LB 1727

    NASA Technical Reports Server (NTRS)

    Turner, T. J.; George, I. M.; Nandra, K.; Grupe, D.; Remillard, R.; Leighly, K.; Marshall, H. L.

    1998-01-01

    We discuss the properties of the Seyfert 1.5 galaxy LB 1727 based upon the analysis of two ASCA observations, a two-month Rosat monitoring campaign, and optical data. The target is identified with the HEAO-A1 source 1H0419-577, so it has been observed by ASCA and ROSAT in order to obtain better X-ray variability and spectra data. Only modest (20%) variability is observed within or between ASCA and BeppoSAX observations in the approximately 2 - 10 keV band. However, the soft X-ray flux increased by a factor of 3 over a period of 2 months, while it was monitored daily by the ROSAT HRI instrument. The hard X-ray continuum can be parameterized as a power-law of slope Gamma approximately 1.5 - 1.6 across 9.7 - 11 keV in the rest-frame. We also report the first detection of an iron K(alpha) line in this source, consistent with emission from neutral material. The X-ray spectrum steepens sharply below 0.7 keV yielding a power-law of slope Gamma approximately 3.2. There is no evidence for absorption by neutral material, instrinsic to the nucleus. If the nucleus is unattenuated, then the break energy between the soft-excess and hard component is 0.7+/-0.08 keV. An ionized absorber may produce some tum-up in the spectrum at low energies, but a steepening of the underlying continuum is also required to explain the simultaneous ASCA and HRI data. We cannot rule out the possibility that a significant column of ionized material exists in the line-of-sight, if that is true, then the continuum break-energy can only be constrained to lie within the approximately 0.1 - -0.7 keV band.

  6. Reverberation Mapping of the Gamma-Ray Loud Narrow-line Seyfert 1 Galaxy 1H 0323+342

    NASA Astrophysics Data System (ADS)

    Wang, Fang; Du, Pu; Hu, Chen; Bai, Jin-Ming; Wang, Chuan-Jun; Yi, Wei-Min; Wang, Jian-Guo; Zhang, Ju-Jia; Xin, Yu-Xin; Lun, Bao-Li; Chang, Liang; Fan, Yu-Feng

    2016-06-01

    Recently, 1H 0323+342 has attracted a lot of attention as one of several narrow-line Seyfert 1 galaxies detected in the γ-ray band. To understand their central energy engines and jet phenomena, the black hole mass is important. We made use of the Lijiang 2.4 m Telescope to monitor 1H 0323+342 for more than two months. This galaxy is one of the candidates for a monitoring project of super-Eddington accreting massive black holes. The reverberation mapping shows that Hβ emission has a delayed response of {14.8}-2.7+3.9 days with respect to the SDSS g‧ light curve in the rest frame. The optical Fe ii variations were detected after subtracting host contaminations, and a reverberation with a delay of {15.2}-4.1+7.4 days was found in the rest frame. By assuming the viral factor f BLR = 6.17 for the broad-line region (BLR) velocity characterized by FWHM because of the face-on orientation, we find that the black hole mass derived from Hβ is {M}\\bullet ={3.4}-0.6+0.9× {10}7{M}ȯ , and the accretion rate is \\dot{{M}}={1.11}-0.47+0.69, where \\dot{{M}}={\\dot{M}}\\bullet {c}2/{L}{{Edd}}, {\\dot{M}}\\bullet is the mass accretion rate, L Edd is the Eddington luminosity, and c is the speed of light. This black hole is one order less massive than that given by the Magorrian relation from the bulge mass. We test the relation between accretion rates and radio-loudnesses in all mapped radio-loud active galactic nuclei, and find that 1H 0323+342 falls within this group.

  7. First X-ray Statistical Tests for Clumpy Torii Models: Constraints from RXTE monitoring of Seyfert AGN

    NASA Astrophysics Data System (ADS)

    Markowitz, A.

    2015-09-01

    We summarize two papers providing the first X-ray-derived statistical constraints for both clumpy-torus model parameters and cloud ensemble properties. In Markowitz, Krumpe, & Nikutta (2014), we explored multi-timescale variability in line-of-sight X-ray absorbing gas as a function of optical classification. We examined 55 Seyferts monitored with the Rossi X-ray Timing Explorer, and found in 8 objects a total of 12 eclipses, with durations between hours and years. Most clouds are commensurate with the outer portions of the BLR, or the inner regions of infrared-emitting dusty tori. The detection of eclipses in type Is disfavors sharp-edged tori. We provide probabilities to observe a source undergoing an absorption event for both type Is and IIs, yielding constraints in [N_0, sigma, i] parameter space. In Nikutta et al., in prep., we infer that the small cloud angular sizes, as seen from the SMBH, imply the presence of >10^7 clouds in BLR+torus to explain observed covering factors. Cloud size is roughly proportional to distance from the SMBH, hinting at the formation processes (e.g. disk fragmentation). All observed clouds are sub-critical with respect to tidal disruption; self-gravity alone cannot contain them. External forces (e.g. magnetic fields, ambient pressure) are needed to contain them, or otherwise the clouds must be short-lived. Finally, we infer that the radial cloud density distribution behaves as 1/r^{0.7}, compatible with VLTI observations. Our results span both dusty and non-dusty clumpy media, and probe model parameter space complementary to that for short-term eclipses observed with XMM-Newton, Suzaku, and Chandra.

  8. Night-to-night variation in the optical emission lines in the nuclear spectrum of the Seyfert galaxy NGC 3227

    NASA Astrophysics Data System (ADS)

    Pronik, I.; Metik, L.

    2004-06-01

    Fifty-three spectrograms in the optical region (3700-7300 Å)with a spectral resolution of about 8 Å have been obtained for the Seyfert nucleus of the galaxy NGC 3227 with the 6 m telescope on 12-15 January 1977 while the nucleus was in the historically important epoch of its extreme maximum brightness. The width of the slit was 1?, and the length of the box during the spectral measurements was 1.5?. The data obtained by us and those compiled from literature showed that profiles of the Balmer lines Ha, Hß and H? are different, demonstrating that the gas emitting these lines is highly self-absorbed. The profiles of the Balmer lines contain various components that kept their positions (radial velocities) over 10 years. The components can reflect long-lived flows or jets in the broad-line region (BLR). A blue bump at a radial velocity of -5000 km s-1 in the H? profile was revealed. Variations in the intensities of the revealed components and broad wings of the emission lines Hß and H? profiles were detected over 3 days. The same variations were observed by us earlier in the emission line profiles of the NGC 7469 nucleus spectrum. We suppose that the revealed night-to-night variability of the emission line spectra of the galaxies NGC 3227 and NGC 7469 is a result of short-time flares in the BLR. The dimension of the flare region is less than 0.2 of the whole BLR dimension. The density of the flare region is two to three orders of magnitude higher than that of the overall BLR. One of the possible explanations for the observed event can be proposed in the framework of a model of short-lived shocks in long-lived flows or jets.

  9. Relativistic Iron K Emission and Absorption in the Seyfert 1.9 Galaxy MCG-05-23-16

    NASA Technical Reports Server (NTRS)

    Braito, V.; Reeves, J. N.; Dewangan, G. C.; George, I.; Griffiths, R.; Markowitz, A.; Nandra, K.; Porquet, D.; Ptak, A.; Turner, T. J.; Yaqoob, T.; Weaver, K.

    2007-01-01

    We present the results of the simultaneous deep XMM-Newton and Chandra observations of the bright Seyfert 1.9 galaxy MCG-5-23-16, which is thought to have one of the best known examples of a relativistically broadened iron Kalpha line. We detected a narrow sporadic absorption line at 7.7 keV which appears to be variable on a time-scale of 20 ksec. If associated with FeXXVI this absorption is indicative of a possible variable high ionization, high velocity outflow. The time averaged spectral analysis shows that the iron K-shell complex is best modeled with an unresolved narrow emission component (FWHM less than 5000 kilometers per second, EW approx. 60 eV) plus a broad component. This latter component has FWHM approx. 44000 kilometers per second, an EW approx. 50 eV and its profile is well described with an emission line originating from the accretion disk viewed with an inclination angle approx. 40 deg. and with the emission arising from within a few tens of gravitational radii of the central black hole. The time-resolved spectral analysis of the XMM-Newton EPIC-pn spectrum shows that both the narrow and broad components of the Fe K emission line appear to be constant within the errors. The analysis of the XMM-Newton/RGS spectrum reveals that the soft X-ray emission of MCG-5-23-16 is likely dominated by several emission lines superimposed on an unabsorbed scattered power-law continuum. The lack of strong Fe L shell emission together with the detection of a strong forbidden line in the O VII triplet supports a scenario where the soft X ray emission lines are produced in a plasma photoionized by the nuclear emission.

  10. Reverberation Mapping of the Gamma-Ray Loud Narrow-line Seyfert 1 Galaxy 1H 0323+342

    NASA Astrophysics Data System (ADS)

    Wang, Fang; Du, Pu; Hu, Chen; Bai, Jin-Ming; Wang, Chuan-Jun; Yi, Wei-Min; Wang, Jian-Guo; Zhang, Ju-Jia; Xin, Yu-Xin; Lun, Bao-Li; Chang, Liang; Fan, Yu-Feng

    2016-06-01

    Recently, 1H 0323+342 has attracted a lot of attention as one of several narrow-line Seyfert 1 galaxies detected in the γ-ray band. To understand their central energy engines and jet phenomena, the black hole mass is important. We made use of the Lijiang 2.4 m Telescope to monitor 1H 0323+342 for more than two months. This galaxy is one of the candidates for a monitoring project of super-Eddington accreting massive black holes. The reverberation mapping shows that Hβ emission has a delayed response of {14.8}-2.7+3.9 days with respect to the SDSS g‧ light curve in the rest frame. The optical Fe ii variations were detected after subtracting host contaminations, and a reverberation with a delay of {15.2}-4.1+7.4 days was found in the rest frame. By assuming the viral factor f BLR = 6.17 for the broad-line region (BLR) velocity characterized by FWHM because of the face-on orientation, we find that the black hole mass derived from Hβ is {M}\\bullet ={3.4}-0.6+0.9× {10}7{M}⊙ , and the accretion rate is \\dot{{M}}={1.11}-0.47+0.69, where \\dot{{M}}={\\dot{M}}\\bullet {c}2/{L}{{Edd}}, {\\dot{M}}\\bullet is the mass accretion rate, L Edd is the Eddington luminosity, and c is the speed of light. This black hole is one order less massive than that given by the Magorrian relation from the bulge mass. We test the relation between accretion rates and radio-loudnesses in all mapped radio-loud active galactic nuclei, and find that 1H 0323+342 falls within this group.

  11. Far Ultraviolet Spectroscopic Explorer Observations of the Seyfert 1.5 Galaxy NGC 5548 in a Low State

    NASA Technical Reports Server (NTRS)

    Brotherton, M. S.; Green, R. F.; Kriss, G. A.; Oegerle, W.; Kaiser, M. E.; Zheng, W.; Hutchings, J. B.; Fisher, Richard R. (Technical Monitor)

    2001-01-01

    We present far-ultraviolet spectra of the Seyfert 1.5 galaxy NGC 5548 obtained in 2000 June with the Far Ultraviolet Spectroscopic Explorer (FUSE). Our data span the observed wavelength range 915-1185 A at a resolution of approximately 20 km s(exp -1). The spectrum shows a weak continuum and emission from O VI (lambda)(lambda)1032, 1038, C III (lambda)977, and He II (lambda)1085. The FUSE data were obtained when the AGN (Active Galactic Nuclei) was in a low state, which has revealed strong, narrow O VI emission lines. We also resolve intrinsic, associated absorption lines of O VI and the Lyman series. Several distinct kinematic components are present, spanning a velocity range of approximately 0 to -1300 km s(exp -1) relative to systemic, with kinematic structure similar to that seen in previous observations of longer wavelength ultraviolet (UV) lines. We explore the relationships between the far-UV (ultraviolet) absorbers and those seen previously in the UV and X-rays. We find that the high-velocity UV absorption component is consistent with being low-ionization, contrary to some previous claims, and is consistent with its non-detection in high-resolution X-ray spectra. The intermediate velocity absorbers, at -300 to -400 km s(exp -1), show H I and O VI column densities consistent with having contributions from both a high-ionization X-ray absorber and a low-ionization UV absorber. No single far-UV absorbing component can be solely identified with the X-ray absorber.

  12. Fermi/LAT Observations of Swift/BAT Seyfert Galaxies: On the Contribution of Radio-Quiet Active Galactic Nuclei to the Extragalactic gamma-Ray Background

    NASA Technical Reports Server (NTRS)

    Teng, Stacy H.; Mushotzky, Richard F.; Sambruna, Rita M.; Davis, David S.; Reynolds, Christopher S.

    2011-01-01

    We present the analysis of 2.1 years of Fermi Large Area Telescope (LAT) data on 491 Seyfert galaxies detected by the Swift Burst Alert Telescope (BAT) survey. Only the two nearest objects, NGC 1068 and NGC 4945, which were identified in the Fermi first year catalog, are detected. Using Swift/BAT and radio 20 cm fluxes, we define a new radio-loudness parameter R(sub X,BAT) where radio-loud objects have logR(sub X,BAT) > -4.7. Based on this parameter, only radio-loud sources are detected by Fermi/LAT. An upper limit to the flux of the undetected sources is derived to be approx.2x10(exp -11) photons/sq cm/s, approximately seven times lower than the observed flux of NGC 1068. Assuming a median redshift of 0.031, this implies an upper limit to the gamma-ray (1-100 GeV) luminosity of < approx.3x10(exp 41) erg/s. In addition, we identified 120 new Fermi/LAT sources near the Swift/BAT Seyfert galaxies with significant Fermi/LAT detections. A majority of these objects do not have Swift/BAT counterparts, but their possible optical counterparts include blazars, flat-spectrum radio quasars, and quasars.

  13. FERMI/LAT OBSERVATIONS OF SWIFT/BAT SEYFERT GALAXIES: ON THE CONTRIBUTION OF RADIO-QUIET ACTIVE GALACTIC NUCLEI TO THE EXTRAGALACTIC {gamma}-RAY BACKGROUND

    SciTech Connect

    Teng, Stacy H.; Mushotzky, Richard F.; Reynolds, Christopher S.; Sambruna, Rita M.; Davis, David S.

    2011-12-01

    We present the analysis of 2.1 years of Fermi Large Area Telescope (LAT) data on 491 Seyfert galaxies detected by the Swift Burst Alert Telescope (BAT) survey. Only the two nearest objects, NGC 1068 and NGC 4945, which were identified in the Fermi first year catalog, are detected. Using Swift/BAT and radio 20 cm fluxes, we define a new radio-loudness parameter R{sub X,BAT} where radio-loud objects have log R{sub X,BAT} > -4.7. Based on this parameter, only radio-loud sources are detected by Fermi/LAT. An upper limit to the flux of the undetected sources is derived to be {approx}2 Multiplication-Sign 10{sup -11} photons cm{sup -2} s{sup -1}, approximately seven times lower than the observed flux of NGC 1068. Assuming a median redshift of 0.031, this implies an upper limit to the {gamma}-ray (1-100 GeV) luminosity of {approx}< 3 Multiplication-Sign 10{sup 41} erg s{sup -1}. In addition, we identified 120 new Fermi/LAT sources near the Swift/BAT Seyfert galaxies with significant Fermi/LAT detections. A majority of these objects do not have Swift/BAT counterparts, but their possible optical counterparts include blazars, flat-spectrum radio quasars, and quasars.

  14. Search for Pulsations from a Nearby Millisecond Pulsar and Wasilewski 49: Mirror for a Hidden Seyfert 1 Nucleus

    NASA Technical Reports Server (NTRS)

    Halpern, Jules P.

    1999-01-01

    , such modulation will be further evidence that surface reheating by the impact of particles accelerated along open fiel;d lines operates in these approximately 10(exp -9) year old pulsars. In a second study, a new AM Her star serendipitously in a 25 day observation was detected with the EUVE satellite. A coherent period of 85.82 min is present in the EUVE Deep Survey imager light curve of this source. A spectroscopic optical identification is made with a 19th magnitude blue star that has H and He emission lines, and broad cyclotron humps typical of a magnetic cataclysmic variable. A lower limit to the polar magnetic field of 50 MG is estimated from the spacing of the cyclotron harmonics. EUVE J0425.6-5714 is also detected in archival ROSAT HRI observations spanning two months, and its stable and highly structured light curve permits us to fit a coherent ephemeris linking the ROSAT and EUVE data over a 1.3 yr gap. The derived period is 85.82107 +/- 0.00020 min, and the ephemeris should be accurate to 0.1 cycles until the year 2005. A narrow but partial X-ray eclipse suggests that this object belongs to the group of AM Her stars whose viewing geometry is such that the accretion stream periodically occults the soft X-ray emitting accretion spot on the surface of the white dwarf. A non-detection of hard X-rays from ASCA observations that are contemporaneous with the ROSAT HRI shows that the soft X-rays must dominate by at least an order of magnitude, which is consistent with a known trend among AM Her stars with large magnetic field. This object should not be confused with the Seyfert galaxy IH 0419-577 (= LB 1727), another X-ray/EUV source which lies only 3'95 away, and was the principal target of these monitoring observations. In a third report; the identity of the persistent high-energy (> 100 MeV) gamma-ray sources in the Galaxy, still largely a mystery is investigated. The second installment of the EGRET (2EG) lists a total of 128 sources, of which 51 are likely or

  15. Search for Pulsations from a Nearby Millisecond Pulsar and Wasilewski 49: Mirror for a Hidden Seyfert 1 Nucleus

    NASA Astrophysics Data System (ADS)

    Halpern, Jules P.

    1999-03-01

    of particles accelerated along open fiel;d lines operates in these approximately 10-9 year old pulsars. In a second study, a new AM Her star serendipitously in a 25 day observation was detected with the EUVE satellite. A coherent period of 85.82 min is present in the EUVE Deep Survey imager light curve of this source. A spectroscopic optical identification is made with a 19th magnitude blue star that has H and He emission lines, and broad cyclotron humps typical of a magnetic cataclysmic variable. A lower limit to the polar magnetic field of 50 MG is estimated from the spacing of the cyclotron harmonics. EUVE J0425.6-5714 is also detected in archival ROSAT HRI observations spanning two months, and its stable and highly structured light curve permits us to fit a coherent ephemeris linking the ROSAT and EUVE data over a 1.3 yr gap. The derived period is 85.82107 +/- 0.00020 min, and the ephemeris should be accurate to 0.1 cycles until the year 2005. A narrow but partial X-ray eclipse suggests that this object belongs to the group of AM Her stars whose viewing geometry is such that the accretion stream periodically occults the soft X-ray emitting accretion spot on the surface of the white dwarf. A non-detection of hard X-rays from ASCA observations that are contemporaneous with the ROSAT HRI shows that the soft X-rays must dominate by at least an order of magnitude, which is consistent with a known trend among AM Her stars with large magnetic field. This object should not be confused with the Seyfert galaxy IH 0419-577 (= LB 1727), another X-ray/EUV source which lies only 3'95 away, and was the principal target of these monitoring observations. In a third report; the identity of the persistent high-energy (> 100 MeV) gamma-ray sources in the Galaxy, still largely a mystery is investigated. The second installment of the EGRET (2EG) lists a total of 128 sources, of which 51 are likely or possibly identified with AGNs, five with rotation-powered pulsars, and one is the LMC

  16. Distributions of molecules in the circumnuclear disk and surrounding starburst ring in the Seyfert galaxy NGC 1068 observed with ALMA

    NASA Astrophysics Data System (ADS)

    Takano, Shuro; Nakajima, Taku; Kohno, Kotaro; Harada, Nanase; Herbst, Eric; Tamura, Yoichi; Izumi, Takuma; Taniguchi, Akio; Tosaki, Tomoka

    2014-07-01

    Sensitive observations with the Atacama Large Millimeter/submillimeter Array (ALMA) allow astronomers to observe the detailed distributions of molecules with relatively weak intensity in nearby galaxies. In particular, we report distributions of several molecular transitions including shock and dust related species (13CO J = 1-0, C18O J = 1-0, 13CN N = 1-0, CS J = 2-1, SO JN = 32-21, HNCO JKa,Kc = 50,5-40,4, HC3N J = 11-10, 12-11, CH3OH JK = 2K-1K, and CH3CN JK = 6K-5K) in the nearby Seyfert 2 galaxy NGC 1068 observed with the ALMA early science program. The central ˜ 1'(˜ 4.3 kpc) of this galaxy was observed in the 100-GHz region covering ˜ 96-100 GHz and ˜ 108-111 GHz with an angular resolution of ˜ 4'' × 2'' (290 pc × 140 pc) to study the effects of an active galactic nucleus and its surrounding starburst ring on molecular abundances. Here, we present images and report a classification of molecular distributions into three main categories: (1) molecules concentrated in the circumnuclear disk (CND) (SO JN = 32-21, HC3N J = 11-10, 12-11, and CH3CN JK = 6K-5K), (2) molecules distributed both in the CND and the starburst ring (CS J = 2-1 and CH3OH JK = 2K-1K), and (3) molecules distributed mainly in the starburst ring (13CO J = 1-0 and C18O J = 1-0). Since most of the molecules such as HC3N observed in the CND are easily dissociated by UV photons and X-rays, our results indicate that these molecules must be effectively shielded. In the starburst ring, the relative intensity of methanol at each clumpy region is not consistent with those of 13CO, C18O, or CS. This difference is probably caused by the unique formation and destruction mechanisms of CH3OH.

  17. FE K EMISSION AND ABSORPTION FEATURES IN THE XMM-EPIC SPECTRUM OF THE SEYFERT GALAXY IC 4329A

    NASA Technical Reports Server (NTRS)

    Markowitz, A.; Reeves, J. N.; Braito, V.

    2001-01-01

    We present a re-analysis of the XMM-Newton long-look of the X-ray bright Seyfert galaxy IC 4329a. The Fe K bandpass is dominated by two peaks, consistent with emission from neutral or near-neutral Fe Ka and KP. A relativistic diskline model whereby both peaks are the result of one doubly-peaked diskline profile is found to be a poor description of the data. Models using two relativistic disklines are found to describe the emission profile well. A low-inclination, moderately-relativistic dual-diskline model is possible if the contribution from narrow components, due to distant material, is small or absent. A high-inclination, moderately relativistic profile for each peak is possible if there are roughly equal contributions from both the broad and narrow components. Upper limits on Fe XXV and Fe XXVI emission and absorption at the systemic velocity of IC 4329a are obtained. We also present the results of RXTE monitoring of this source obtained so far; the combined XMM-Newton and RXTE data sets allow us to explore the time-resolved spectral behavior of this source on time scales ranging from hours to 2 years. We find no strong evidence for variability of the Fe Ka emission line on any time scale probed, likely due to the minimal level of continuum variability. We detect a narrow absorption line, at a energy of 7.68 keV in the rest frame of the source; its significance has been confirmed using Monte Carlo simulations. This feature is most likely due to absorption from Fe XXVI blueshifted to approximately 0.1c relative to the systemic velocity, making IC 4329a the lowest-redshift AGN known with a high-velocity, highly-ionized outflow component. As is often the case with similar outflows seen in high-luminosity quasars, the estimated mass outflow rate is larger than the inflow accretion rate, signaling that the outflow represents a substantial portion of the total energy budget of the AGN. The outflow could arise from a radiatively-driven disk wind, or it may be in the

  18. The awakening of the γ-ray narrow-Line Seyfert 1 galaxy PKS 1502+036

    NASA Astrophysics Data System (ADS)

    D'Ammando, F.; Orienti, M.; Finke, J.; Hovatta, T.; Giroletti, M.; Max-Moerbeck, W.; Pearson, T. J.; Readhead, A. C. S.; Reeves, R. A.; Richards, J. L.

    2016-09-01

    After a long low-activity period, a γ-ray flare from the narrow-line Seyfert 1 PKS 1502+036 (z = 0.4089) was detected by the Large Area Telescope (LAT) on board Fermi in 2015. On 2015 December 20 the source reached a daily peak flux, in the 0.1-300 GeV band, of (93 ± 19)× 10-8 ph cm-2 s-1, attaining a flux of (237 ± 71)× 10-8 ph cm-2 s-1 on 3-hr time-scales, which corresponds to an isotropic luminosity of (7.3 ± 2.1)× 1047 erg s-1. The γ-ray flare was not accompanied by significant spectral changes. We report on multi-wavelength radio-to-γ-ray observations of PKS 1502+036 during 2008 August-2016 March by Fermi-LAT, Swift, XMM-Newton, Catalina Real-Time Transient Survey, and the Owens Valley Radio Observatory (OVRO). An increase in activity was observed on 2015 December 22 by Swift in optical, UV, and X-rays. The OVRO 15 GHz light curve reached the highest flux density observed from this source on 2016 January 12, indicating a delay of about three weeks between the γ-ray and 15 GHz emission peaks. This suggests that the γ-ray emitting region is located beyond the broad line region. We compared the spectral energy distribution (SED) of an average activity state with that of the flaring state. The two SED, with the high-energy bump modelled as an external Compton component with seed photons from a dust torus, could be fitted by changing the electron distribution parameters as well as the magnetic field. The fit of the disc emission during the average state constrains the black hole mass to values lower than 108 M⊙. The SED, high-energy emission mechanisms, and γ-ray properties of the source resemble those of a flat spectrum radio quasar.

  19. Sample Design.

    ERIC Educational Resources Information Center

    Ross, Kenneth N.

    1987-01-01

    This article considers various kinds of probability and non-probability samples in both experimental and survey studies. Throughout, how a sample is chosen is stressed. Size alone is not the determining consideration in sample selection. Good samples do not occur by accident; they are the result of a careful design. (Author/JAZ)

  20. Structure of the Circumnuclear Region of Seyfert 2 Galaxies Revealed by Rossi X-Ray Timing Explorer Hard X-Ray Observations of NGC 4945.

    PubMed

    Madejski; Zycki; Done; Valinia; Blanco; Rothschild; Turek

    2000-06-01

    NGC 4945 is one of the brightest Seyfert galaxies on the sky at 100 keV, but is completely absorbed below 10 keV; its absorption column is probably the largest that still allows a direct view of the nucleus at hard X-ray energies. Our observations of it with the Rossi X-Ray Timing Explorer (RXTE) satellite confirm the large absorption, which for a simple phenomenological fit using an absorber with solar abundances implies a column of 4.5+0.4-0.4x1024 cm(-2). Using a more realistic scenario (requiring Monte Carlo modeling of the scattering), we infer the optical depth to Thomson scattering of approximately 2.4. If such a scattering medium were to subtend a large solid angle from the nucleus, it should smear out any intrinsic hard X-ray variability on timescales shorter than the light-travel time through it. The rapid (with a timescale of approximately 1 day) hard X-ray variability of NGC 4945 discovered by us with RXTE implies that the bulk of the extreme absorption in this object does not originate in a parsec-size, geometrically thick molecular torus. Instead, the optically thick material on parsec scales must be rather geometrically thin, subtending a half-angle less than 10 degrees, and it is likely to be the same disk of material that is responsible for the water maser emission observed in NGC 4945. Local number counts of Seyfert 1 and Seyfert 2 galaxies show a large population of heavily obscured active galactic nuclei (AGNs) which are proposed to make up the cosmic X-ray background (CXRB). However, for this to be the case, the absorption geometry in the context of axially symmetric unification schemes must have the obscuring material subtending a large scale height-contrary to our inferences about NGC 4945-implying that NGC 4945 is not a prototype of obscured AGNs postulated to make up the CXRB. The small solid angle of the absorber, together with the black hole mass (of approximately 1.4x106 M( middle dot in circle)) from megamaser measurements, allows a

  1. Capillary sample

    MedlinePlus

    ... using capillary blood sampling. Disadvantages to capillary blood sampling include: Only a limited amount of blood can be drawn using this method. The procedure has some risks (see below). Capillary ...

  2. The size of the narrow-line-emitting region in the Seyfert 1 galaxy NGC 5548 from emission-line variability

    SciTech Connect

    Peterson, B. M.; Denney, K. D.; De Rosa, G.; Grier, C. J.; Pogge, R. W.; Kochanek, C. S.; Bentz, M. C.; Vestergaard, M.; Kilerci-Eser, E.; Dalla Bontà, E.; Ciroi, S.

    2013-12-20

    The narrow [O III] λλ4959, 5007 emission-line fluxes in the spectrum of the well-studied Seyfert 1 galaxy NGC 5548 are shown to vary with time. From this we show that the narrow-line-emitting region has a radius of only 1-3 pc and is denser (n {sub e} ∼ 10{sup 5} cm{sup –3}) than previously supposed. The [O III] line width is consistent with virial motions at this radius given previous determinations of the black hole mass. Since the [O III] emission-line flux is usually assumed to be constant and is therefore used to calibrate spectroscopic monitoring data, the variability has ramifications for the long-term secular variations of continuum and emission-line fluxes, though it has no effect on shorter-term reverberation studies. We present corrected optical continuum and broad Hβ emission-line light curves for the period 1988-2008.

  3. Einstein Observatory SSS and MPC observations of the complex X-ray spectra of Seyfert galaxies. [Solid State Spectrometer and Monitor Proportional Counter

    NASA Technical Reports Server (NTRS)

    Turner, T. J.; Weaver, K. A.; Mushotzky, R. F.; Holt, S. S.; Madejski, G. M.

    1991-01-01

    The X-ray spectra of 25 Seyfert galaxies measured with the Solid State Spectrometer on the Einstein Observatory have been investigated. This new investigation utilizes simultaneous data from the Monitor Proportional Counter, and automatic correction for systematic effects in the Solid State Spectrometer which were previously handled subjectively. It is found that the best-fit single-power-law indices generally agree with those previously reported, but that soft excesses of some form are inferred for about 48 percent of the sources. One possible explanation of the soft excess emission is a blend of soft X-ray lines, centered around 0.8 keV. The implications of these results for accretion disk models are discussed.

  4. SUZAKU MONITORING OF THE SEYFERT 1 GALAXY NGC 5548: WARM ABSORBER LOCATION AND ITS IMPLICATION FOR COSMIC FEEDBACK

    SciTech Connect

    Krongold, Y.; Andrade-Velazquez, M.; Binette, L.; Jimenez-Bailon, E.; Elvis, M.; Nicastro, F.; Brickhouse, N. S.; Liu, Y.; Wilkes, B.; Mathur, S.; Reeves, J. N.; Grupe, D.; McHardy, I. M.; Minezaki, T.; Yoshii, Y.

    2010-02-10

    We present a 2 month Suzaku X-ray monitoring of the Seyfert 1 galaxy NGC 5548. The campaign consists of seven observations (with exposure time of {approx}30 ks each), separated by {approx}1 week. This paper focus on the X-ray Imaging Spectrometer data of NGC 5548. We analyze the response in the opacity of the gas that forms the well-known ionized absorber in this source for ionizing flux variations. Despite variations by a factor of {approx}4 in the impinging continuum, the soft X-ray spectra of the source show little spectral variations, suggesting no response from the ionized absorber. A detailed time modeling of the spectra confirms the lack of opacity variations for an absorbing component with high ionization (U{sub X} {approx} -0.85), and high outflow velocity (v{sub out} {approx} 1040 km s{sup -1}), as the ionization parameter was found to be consistent with a constant value during the whole campaign. Instead, the models suggest that the ionization parameter of a low ionization (U{sub X} {approx} -2.8), low velocity (v{sub out} {approx} 590 km s{sup -1}) absorbing component might be changing linearly with the ionizing flux, as expected for gas in photoionization equilibrium. However, given the lack of spectral variations among observations, we consider the variations in this component as tentative. Using the lack of variations, we set an upper limit of n{sub e} < 2.0 x 10{sup 7} cm{sup -3} for the electron density of the gas forming the high ionization, high velocity component. This implies a large distance from the continuum source (R>0.033 pc; R>5000R{sub S} ). If the variations in the low ionization, low velocity component are real, they imply n{sub e} >9.8 x 10{sup 4} cm{sup -3} and R < 3 pc. We discuss our results in terms of two different scenarios: a large-scale outflow originating in the inner parts of the accretion disk, or a thermally driven wind originating much farther out. Given the large distance of the wind, the implied mass outflow rate is

  5. Simultaneous Ultraviolet and X-Ray Observations of the Seyfert Galaxy NGC 4151. II. Physical Conditions in the UV Absorbers

    NASA Astrophysics Data System (ADS)

    Kraemer, S. B.; Crenshaw, D. M.; Gabel, J. R.; Kriss, G. A.; Netzer, H.; Peterson, B. M.; George, I. M.; Gull, T. R.; Hutchings, J. B.; Mushotzky, R. F.; Turner, T. J.

    2006-12-01

    We present a detailed analysis, including photoionization modeling, of the intrinsic absorption in the Seyfert 1 galaxy NGC 4151 using ultraviolet (UV) spectra from the Hubble Space Telescope Space Telescope Imaging Spectrograph and the Far Ultraviolet Spectrographic Explorer obtained 2002 May as part of a set of contemporaneous observations that included Chandra High Energy Transmission Grating Spectrometer spectra. In our analysis of the Chandra spectra, we determined that the X-ray absorption was dominated by two components: a high-ionization absorber, revealed by the presence of H-like and He-like lines of Mg, Si, and S, and a lower ionization absorber, in which inner shell absorption lines from lower ionization species of these elements formed. We identified the latter as the source of the saturated UV lines of O VI, C IV, and N V associated with the absorption feature at a radial velocity of ~-500 km s-1, which we referred to as component D+E. In the present work, we have derived tighter constrains on the line-of-sight covering factors, densities, and radial distances of the absorbers. We confirm the presence of the three subcomponents of D+E described in our previous paper, with line-of-sight covering factors (Clos) ranging from ~0.5 to 0.9, and find evidence for a fourth component, D+Ed, characterized by low ionization and a Clos~0.2. The complexity of the UV absorption in NGC 4151 may be a consequence of the fact that we are viewing the black hole/accretion disk system at a relatively high inclination and, therefore, may be detecting the densest part of the flow. Our deconvolution of the underlying C IV emission indicates that D+E must lie outside the intermediate line region (ILR), hence at a radial distance of ~0.1 pc. We find that the equivalent widths (EWs) of the low-ionization lines associated with D+E varied over the period from 1999 July to 2002 May. Although over part of this time, the variations were correlated with changes in the UV continuum

  6. XMM-Newton observation of the Seyfert 1.8 ESO 113-G010: Discovery of a highly redshifted iron line at 5.4 keV

    NASA Astrophysics Data System (ADS)

    Porquet, D.; Reeves, J. N.; Uttley, P.; Turner, T. J.

    2004-11-01

    We present a spectral analysis of the Seyfert 1.8 ESO 113-G010 observed with XMM-Newton for 4 ks. The spectrum shows a soft excess below 0.7 keV and more interestingly a narrow emission Gaussian line at 5.4 keV (in its rest-frame), most probably originating from a redshifted iron Kα line. No significant line at or above 6.4 keV is found contrary to other objects showing redshifted lines, ruling out a strong blue-wing to the line profile. The line is detected at 99% confidence, from performing Monte Carlo simulations which fully account for the range of energies where a narrow iron line is likely to occur. The energy of the line could indicate emission from relativistic (0.17-0.23 c) ejected matter moving away from the observer, as proposed for Mrk 766 by Turner et al. (\\cite{Tu04}, ApJ, 603, 62). Alternatively, the emission from a narrow annulus at the surface of the accretion disk is unlikely due to the very small inclination angle (i.e. less than 10°) required to explain the narrow, redshifted line in this intermediate Seyfert galaxy. However emission from a small, localized hot-spot on the disk, occurring within a fraction of a complete disk orbit, could also explain the redshifted line. This scenario would be directly testable in a longer observation, as one would see significant variations in the energy and intensity of the line within an orbital timescale.

  7. RESOLVING THE BRIGHT HCN(1–0) EMISSION TOWARD THE SEYFERT 2 NUCLEUS OF M51: SHOCK ENHANCEMENT BY RADIO JETS AND WEAK MASING BY INFRARED PUMPING?

    SciTech Connect

    Matsushita, Satoki; Trung, Dinh-V-; Boone, Frédéric; Krips, Melanie; Lim, Jeremy; Muller, Sebastien

    2015-01-20

    We present high angular resolution observations of the HCN(1-0) emission (at ∼1'' or ∼34 pc), together with CO J = 1-0, 2-1, and 3-2 observations, toward the Seyfert 2 nucleus of M51 (NGC 5194). The overall HCN(1-0) distribution and kinematics are very similar to that of the CO lines, which have been indicated as the jet-entrained molecular gas in our past observations. In addition, high HCN(1-0)/CO(1-0) brightness temperature ratio of about unity is observed along the jets, similar to that observed at the shocked molecular gas in our Galaxy. These results strongly indicate that both diffuse and dense gases are entrained by the jets and outflowing from the active galactic nucleus. The channel map of HCN(1-0) at the systemic velocity shows a strong emission right at the nucleus, where no obvious emission has been detected in the CO lines. The HCN(1-0)/CO(1-0) brightness temperature ratio at this region reaches >2, a value that cannot be explained considering standard physical/chemical conditions. Based on our calculations, we suggest infrared pumping and possibly weak HCN masing, but still requiring an enhanced HCN abundance for the cause of this high ratio. This suggests the presence of a compact dense obscuring molecular gas in front of the nucleus of M51, which remains unresolved at our ∼1'' (∼34 pc) resolution, and consistent with the Seyfert 2 classification picture.

  8. Formation of permitted lines in the spectrum of type 1 Seyfert galaxies and quasars. II - Fe II lines and the low excitation region

    NASA Astrophysics Data System (ADS)

    Collin-Souffrin, S.; Joly, M.; Dumont, S.; Heidmann, N.

    1980-03-01

    Following a previous study (Collin-Souffrin et al., 1979) we investigate the relative intensities of the visible and UV lines of the intense Fe II spectrum of type 1 Seyfert galaxies and quasars. A 9-level atom is used in the computation of the line intensities and relatively accurate collision strengths are computed as we devote particular attention to the collisional excitation mechanism. We confirm that the excitation mechanism is collisional: we show that, in addition to the drawbacks mentioned in Paper I, if the excitation was radiative, the line intensities would be too small compared to the observations. We find that relative intensities of the Fe II lines and of the Mg II 2798 line are well accounted for by an emission region with 1010 ≦ ne ≦ 1011 and 7500 ≦ Te ≦ 10,000 °K. The optical thickness in the UV lines of Fe II is large (˜105). We examine also other low excitation lines and show that Hα is likely to be emitted at least partly by the same Fe II region, while Lα, Si II, O I, should be emitted by a hotter region and Ca II by a colder one. The Fe II region is ionized by collisions from level 2 of hydrogen which is populated by the trapped Lα photons (τLα ˜109). We discuss the geometry of this Fe II region, and find typical dimensions of R ˜ 1016 cm, and H (thickness) ˜ 1014-1016 cm. Finally we examine the significance of this region and conclude that it is likely to be the outer part of an extended accretion disk completely shielded from the UV and X radiation of the central object. We discuss the reality of the photoionized models and, although we are not able to give a definite answer to this problem, we suggest that the collisional models could perhaps account for all the broad lines in quasars and Seyfert 1 galaxies.

  9. Powder sampling.

    PubMed

    Venables, Helena J; Wells, J I

    2002-01-01

    The factors involved when sampling powder mixes have been reviewed. The various methods are evaluated (manual, automatic, and sub-sampling) and the errors incurred are discussed. Certain rules have been applied to various samplers and their suitability for powder mixtures are described. The spinning riffler is apparently the most suitable, while the use of sample thieves should be avoided due to error and bias.

  10. Sampling Development

    PubMed Central

    Adolph, Karen E.; Robinson, Scott R.

    2011-01-01

    Research in developmental psychology requires sampling at different time points. Accurate depictions of developmental change provide a foundation for further empirical studies and theories about developmental mechanisms. However, overreliance on widely spaced sampling intervals in cross-sectional and longitudinal designs threatens the validity of the enterprise. This article discusses how to sample development in order to accurately discern the shape of developmental change. The ideal solution is daunting: to summarize behavior over 24-hour intervals and collect daily samples over the critical periods of change. We discuss the magnitude of errors due to undersampling, and the risks associated with oversampling. When daily sampling is not feasible, we offer suggestions for sampling methods that can provide preliminary reference points and provisional sketches of the general shape of a developmental trajectory. Denser sampling then can be applied strategically during periods of enhanced variability, inflections in the rate of developmental change, or in relation to key events or processes that may affect the course of change. Despite the challenges of dense repeated sampling, researchers must take seriously the problem of sampling on a developmental time scale if we are to know the true shape of developmental change. PMID:22140355

  11. Sampling Development

    ERIC Educational Resources Information Center

    Adolph, Karen E.; Robinson, Scott R.

    2011-01-01

    Research in developmental psychology requires sampling at different time points. Accurate depictions of developmental change provide a foundation for further empirical studies and theories about developmental mechanisms. However, overreliance on widely spaced sampling intervals in cross-sectional and longitudinal designs threatens the validity of…

  12. Variability and Spectral Studies of Luminous Seyfert 1 Galaxy Fairall 9. Search for the Reflection Component is a Quasar: RXTE and ASCA Observation of a Nearby Radio-Quiet Quasar MR 2251-178

    NASA Technical Reports Server (NTRS)

    Leighly, Karen M.

    1999-01-01

    Monitoring observations with interval of 3 days using RXTE (X Ray Timing Explorer) of the luminous Seyfert 1 galaxy Fairall 9 were performed for one year. The purpose of the observations were to study the variability of Fairall 9 and compare the results with those from the radio-loud object 3C 390.3. The data has been received and analysis is underway, using the new background model. An observation of the quasar MR 2251-178 was made in order to determine whether or not it has a reflection component. Older background models gave an unacceptable subtraction and analysis is underway using the new background model. The observation of NGC 6300 showed that the X-ray spectrum from this Seyfert 2 galaxy appears to be dominated by Compton reflection.

  13. Elevating sampling

    PubMed Central

    Labuz, Joseph M.; Takayama, Shuichi

    2014-01-01

    Sampling – the process of collecting, preparing, and introducing an appropriate volume element (voxel) into a system – is often under appreciated and pushed behind the scenes in lab-on-a-chip research. What often stands in the way between proof-of-principle demonstrations of potentially exciting technology and its broader dissemination and actual use, however, is the effectiveness of sample collection and preparation. The power of micro- and nanofluidics to improve reactions, sensing, separation, and cell culture cannot be accessed if sampling is not equally efficient and reliable. This perspective will highlight recent successes as well as assess current challenges and opportunities in this area. PMID:24781100

  14. SAMPLING SYSTEM

    DOEpatents

    Hannaford, B.A.; Rosenberg, R.; Segaser, C.L.; Terry, C.L.

    1961-01-17

    An apparatus is given for the batch sampling of radioactive liquids such as slurries from a system by remote control, while providing shielding for protection of operating personnel from the harmful effects of radiation.

  15. Simultaneous NuSTAR and XMM-Newton 0.5-80 KeV Spectroscopy of the Narrow-Line Seyfert 1 Galaxy SWIFT J2127.4+5654

    NASA Technical Reports Server (NTRS)

    Marinucci, A.; Matt, G.; Kara, E.; Miniutti, G.; Elvis, M.; Arevalo, P.; Ballantyne, D. R.; Balokovic, M.; Bauer, F.; Brenneman, L.; Boggs, S. E.; Cappi, M.; Christensen, F. E.; Craig, W. W.; Fabian, A. C.; Fuerst, F.; Hailey, C. J.; Harrison, F. A.; Risaliti, G.; Reynolds, C. S.; Stern, D. K.; Walton, D. J.; Zhang, W.

    2014-01-01

    We present a broad-band spectral analysis of the joint XMM-Newton and Nuclear Spectroscopic Telescope Array observational campaign of the narrow-line Seyfert 1 SWIFT J2127.4+5654, consisting of 300 kiloseconds performed during three XMM-Newton orbits. We detect a relativistic broadened iron K-alpha line originating from the innermost regions of the accretion disc surrounding the central black hole, from which we infer an intermediate spin of a = 0.58 (sup +0.11) (sub -0.17). The intrinsic spectrum is steep (gamma = 2.08 plus or minus 0.01) as commonly found in narrow-line Seyfert 1 galaxies, while the cutoff energy (E (sub c) = 108 (sup +11) (sub -10) kiloelectronvolts) falls within the range observed in broad-line Seyfert 1 galaxies. We measure a low-frequency lag that increases steadily with energy, while at high frequencies, there is a clear lag following the shape of the broad Fe K emission line. Interestingly, the observed Fe K lag in SWIFT J2127.4+5654 is not as broad as in other sources that have maximally spinning black holes. The lag amplitude suggests a continuum-to-reprocessor distance of about 10-20 radius of gyration. These timing results independently support an intermediate black hole spin and a compact corona.

  16. Mid- and Near-infrared spectral properties of a sample of Swift-BAT X-ray selected AGNs

    NASA Astrophysics Data System (ADS)

    Castro, Angel; Miyaji, Takamitsu; Malkan, Matthew A.; Ichikawa, Kohei; Ueda, Yoshihiro; Shirahata, M.; Nakagawa, Takao; Imanishi, Masatoshi; Oyabu, Shinki

    2015-08-01

    We present a comparative study of the mid- (MIR) to near-infrared (NIR) properties of a sample of X-ray selected AGNs from the Swift/Burst Alert Telescope (BAT) 70-month all-sky hard X-ray (14-195 keV) survey. For a sample of 78 AGNs, including both Seyfert 1 and Seyfert 2 sources with black hole masses derived from 2MASS K-band magnitudes and literature, we obtain spectroscopic data from the IRC (2.5 - 5 μm) and IRS (in the 5-14 μm band) instruments onboard the Akari and Spitzer satellites, respectively. We test possible correlations between the 3.3, 6.2, 7.7, 8.6, 11.2 and 12.7 μm polycyclic aromatic hydrocarbon (PAH) emission features, the continuum slope and CO optical depth, as well as CO2, H2O, and amorphous silicates. Using the 3.3, 6.2 and 11.3 μm PAH emission features as a proxy for the star-formation rate (SFR) we report the AGN type and Eddington-ratio dependences of circum-nuclear star formation.

  17. Solar magnetic field studies using the 12 micron emission lines. I - Quiet sun time series and sunspot slices

    NASA Technical Reports Server (NTRS)

    Deming, Drake; Boyle, Robert J.; Jennings, Donald E.; Wiedemann, Gunter

    1988-01-01

    The use of the extremely Zeeman-sensitive IR emission line Mg I, at 12.32 microns, to study solar magnetic fields. Time series observations of the line in the quiet sun were obtained in order to determine the response time of the line to the five-minute oscillations. Based upon the velocity amplitude and average period measured in the line, it is concluded that it is formed in the temperature minimum region. The magnetic structure of sunspots is investigated by stepping a small field of view in linear 'slices' through the spots. The region of penumbral line formation does not show the Evershed outflow common in photospheric lines. The line intensity is a factor of two greater in sunspot penumbrae than in the photosphere, and at the limb the penumbral emission begins to depart from optical thinness, the line source function increasing with height. For a spot near disk center, the radial decrease in absolute magnetic field strength is steeper than the generally accepted dependence.

  18. The 12 micron band of ethane: A spectral catalog from 765 cm(-1) to 900 cm(-1)

    NASA Technical Reports Server (NTRS)

    Atakan, A. K.; Blass, W. E.; Brault, J. W.; Daunt, S. J.; Halsey, G. W.; Jennings, D. E.; Reuter, D. C.; Susskind, J.

    1983-01-01

    The high resolution laboratory absorption spectrum of the 12 micro band of ethane gas is studied. The data were obtained using the McMath Solar Telescope 1 meter Fourier Transform interferometer at Kitt Peak National Observatory and tunable diode laser spectrometers at the University of Tennessee and NASA/Goddard Space Flight Center. Over 200 individual vibration rotation transitions were analyzed taking into account many higher order effects including torsional splitting. Line positions were reproduced to better than 0.001/cm. Both ground and upper state molecular constants were determined in the analysis. The experimental details, the analysis procedures and the results are addressed. A list of ethane transitions occurring near (14)CO2 laser lines needed for heterodyne searches for C2H6 in extraterrestrial sources is also included. A spectral catalog of the ethane nu sub g fundamental from 765/cm to 900/cm is provided. A high dispersion (1/cm 12 in.) plot of both the Kitt Peak interferometric data and a simulated spectrum with Doppler limited resolution, a table of over 8500 calculated transitions listed quantum number assignments, frequencies and intensities are provided.

  19. SAMPLING OSCILLOSCOPE

    DOEpatents

    Sugarman, R.M.

    1960-08-30

    An oscilloscope is designed for displaying transient signal waveforms having random time and amplitude distributions. The oscilloscopc is a sampling device that selects for display a portion of only those waveforms having a particular range of amplitudes. For this purpose a pulse-height analyzer is provided to screen the pulses. A variable voltage-level shifter and a time-scale rampvoltage generator take the pulse height relative to the start of the waveform. The variable voltage shifter produces a voltage level raised one step for each sequential signal waveform to be sampled and this results in an unsmeared record of input signal waveforms. Appropriate delay devices permit each sample waveform to pass its peak amplitude before the circuit selects it for display.

  20. Sampling apparatus

    DOEpatents

    Gordon, Norman R.; King, Lloyd L.; Jackson, Peter O.; Zulich, Alan W.

    1989-01-01

    A sampling apparatus is provided for sampling substances from solid surfaces. The apparatus includes first and second elongated tubular bodies which telescopically and sealingly join relative to one another. An absorbent pad is mounted to the end of a rod which is slidably received through a passageway in the end of one of the joined bodies. The rod is preferably slidably and rotatably received through the passageway, yet provides a selective fluid tight seal relative thereto. A recess is formed in the rod. When the recess and passageway are positioned to be coincident, fluid is permitted to flow through the passageway and around the rod. The pad is preferably laterally orientable relative to the rod and foldably retractable to within one of the bodies. A solvent is provided for wetting of the pad and solubilizing or suspending the material being sampled from a particular surface.

  1. Sampling apparatus

    DOEpatents

    Gordon, N.R.; King, L.L.; Jackson, P.O.; Zulich, A.W.

    1989-07-18

    A sampling apparatus is provided for sampling substances from solid surfaces. The apparatus includes first and second elongated tubular bodies which telescopically and sealingly join relative to one another. An absorbent pad is mounted to the end of a rod which is slidably received through a passageway in the end of one of the joined bodies. The rod is preferably slidably and rotatably received through the passageway, yet provides a selective fluid tight seal relative thereto. A recess is formed in the rod. When the recess and passageway are positioned to be coincident, fluid is permitted to flow through the passageway and around the rod. The pad is preferably laterally orientable relative to the rod and foldably retractable to within one of the bodies. A solvent is provided for wetting of the pad and solubilizing or suspending the material being sampled from a particular surface. 15 figs.

  2. Simultaneous Ultraviolet and X-Ray Observations of Seyfert Galaxy NGC 4151. I. Physical Conditions in the X-Ray Absorbers

    NASA Astrophysics Data System (ADS)

    Kraemer, S. B.; George, I. M.; Crenshaw, D. M.; Gabel, J. R.; Turner, T. J.; Gull, T. R.; Hutchings, J. B.; Kriss, G. A.; Mushotzky, R. F.; Netzer, H.; Peterson, B. M.; Behar, Ehud

    2005-11-01

    We present a detailed analysis of the intrinsic X-ray absorption in the Seyfert 1 galaxy NGC 4151 using Chandra High Energy Transmission Grating Spectrometer data obtained in 2002 May as part of a program that included simultaneous ultraviolet (UV) spectra using the Hubble Space Telescope Space Telescope Imaging Spectrograph and the Far Ultraviolet Spectrographic Explorer. Previous studies, most recently using Advanced Satellite for Cosmology and Astrophysics (ASCA) spectra, revealed a large (>1022 cm-2) column of intervening gas, which has varied both in ionization state and total column density. NGC 4151 was in a relatively low flux state during the observations reported here (~25% of its historic maximum), although roughly 2.5 times as bright in the 2-10 keV band as during a Chandra observation in 2000. At both epochs, the soft X-ray band was dominated by emission lines, which show no discernible variation in flux between the two observations. The 2002 Chandra data show the presence of a very highly ionized absorber, in the form of H-like and He-like Mg, Si, and S lines, as well as lower ionization gas via the presence of inner-shell absorption lines from lower ionization species of these elements. The latter accounts for both the bulk of the soft X-ray absorption and the high covering factor UV absorption lines of O VI, C IV, and N V with outflow velocities ~500 km s-1. The presence of high-ionization gas, which is not easily detected at low resolution (e.g., with ASCA), appears common among Seyfert galaxies. Since this gas is too highly ionized to be radiatively accelerated in sources such as NGC 4151, which is radiating at a small fraction of its Eddington Luminosity, it may be key to understanding the dynamics of mass outflow. We find that the deeper broadband absorption detected in the 2000 Chandra data is the result of both (1) lower ionization of the intervening gas due to the lower ionizing flux and (2) a factor of ~3 higher column density of the lower

  3. Sampling Strategy

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Three locations to the right of the test dig area are identified for the first samples to be delivered to the Thermal and Evolved Gas Analyzer (TEGA), the Wet Chemistry Lab (WCL), and the Optical Microscope (OM) on NASA's Phoenix Mars Lander. These sampling areas are informally labeled 'Baby Bear', 'Mama Bear', and 'Papa Bear' respectively. This image was taken on the seventh day of the Mars mission, or Sol 7 (June 1, 2008) by the Surface Stereo Imager aboard NASA's Phoenix Mars Lander.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  4. The mass and spin of the extreme Narrow Line Seyfert 1 Galaxy 1H 0707-495 and its implications for the trigger for relativistic jets

    NASA Astrophysics Data System (ADS)

    Done, Chris; Jin, Chichuan

    2016-08-01

    Relativistic reflection models of the X-ray spectrum of the `complex' Narrow Line Seyfert 1 (NLS1) 1H 0707-495 require a high-spin, moderate-inclination, low-mass black hole. With these parameters fixed, the observed optical/UV emission directly determines the mass accretion rate through the outer disc and hence predicts the bolometric luminosity. This is 140-260 times the Eddington limit. Such a disc should power a strong wind, and winds are generically expected to be clumpy. Changing inclination angle with respect to a clumpy wind structure gives a possible explanation for the otherwise puzzling difference between `complex' NLS1 such as 1H 0707-495 and `simple' ones like PG 1244+026. Lines of sight which intercept the wind show deep absorption features at iron from the hot phase of the wind, together with stochastic dips and complex absorption when the clumps occult the X-ray source (complex NLS1), whereas both these features are absent for more face-on inclination (simple NLS1). This geometry is quite different from the clean view of a flat disc which is assumed for the spin measurements in relativistic reflection models, so it is possible that even 1H 0707-495 has low spin. If so, this re-opens the simplest and hence very attractive possibility that high black hole spin is a necessary and sufficient condition to trigger highly relativistic (bulk Lorentz factor ˜10-15) jets.

  5. A REVERBERATION LAG FOR THE HIGH-IONIZATION COMPONENT OF THE BROAD-LINE REGION IN THE NARROW-LINE SEYFERT 1 Mrk 335

    SciTech Connect

    Grier, C. J.; Peterson, B. M.; Pogge, R. W.; Martini, Paul; Zu, Y.; Kochanek, C. S.; Shappee, B. J.; Stanek, K. Z.; Araya Salvo, C.; Beatty, T. G.; Bird, J. C.; Denney, K. D.; Bentz, M. C.; Sergeev, S. G.; Borman, G. A.; Bord, D. J.; Che, X.; Chen, C.; Cohen, S. A.; and others

    2012-01-15

    We present the first results from a detailed analysis of photometric and spectrophotometric data on the narrow-line Seyfert 1 (NLS1) galaxy Mrk 335, collected over a 120 day span in the fall of 2010. From these data we measure the lag in the He II {lambda}4686 broad emission line relative to the optical continuum to be 2.7 {+-} 0.6 days and the lag in the H{beta}{lambda}4861 broad emission line to be 13.9 {+-} 0.9 days. Combined with the line width, the He II lag yields a black hole mass M{sub BH} = (2.6 {+-} 0.8) Multiplication-Sign 10{sup 7} M{sub Sun }. This measurement is consistent with measurements made using the H{beta}{lambda}4861 line, suggesting that the He II emission originates in the same structure as H{beta}, but at a much smaller radius. This constitutes the first robust lag measurement for a high-ionization line in an NLS1 galaxy and supports a scenario in which the He II emission originates from gas in virial motion rather than outflow.

  6. MINUTE-SCALE RAPID VARIABILITY OF THE OPTICAL POLARIZATION IN THE NARROW-LINE SEYFERT 1 GALAXY PMN J0948+0022

    SciTech Connect

    Itoh, Ryosuke; Tanaka, Yasuyuki T.; Fukazawa, Yasushi; Kawaguchi, Kenji; Takaki, Katsutoshi; Ueno, Issei; Kawabata, Koji S.; Moritani, Yuki; Uemura, Makoto; Akitaya, Hiroshi; Yoshida, Michitoshi; Ohsugi, Takashi; Hanayama, Hidekazu; Miyaji, Takeshi; Kawai, Nobuyuki

    2013-09-20

    We report on optical photopolarimetric results of the radio-loud narrow-line Seyfert 1 (RL-NLSy1) galaxy PMN J0948+0022 on 2012 December to 2013 February triggered by flux enhancements in the near infrared and γ-ray bands. With the one-shot polarimetry of the Hiroshima One-shot Wide field Polarimeter installed on the Kanata Telescope, we detected very rapid variability in the polarized-flux (PF) light curve on MJD 56281 (2012 December 20). The rise and decay times were about 140 s and 180 s, respectively. The polarization degree (PD) reached 36% ± 3% at the peak of the short-duration pulse, while the polarization angle remained almost constant. In addition, temporal profiles of the total flux and PD showed highly variable but well correlated behavior and discrete correlation function analysis revealed that no significant time lag of more than 10 minutes was present. The high PD and minute-scale variability in PF provides clear evidence of synchrotron radiation from a very compact emission region of ∼10{sup 14} cm size with a highly ordered magnetic field. Such micro-variability of polarization is also observed in several blazar jets, but its complex relation between total flux and PD are explained by a multi-zone model in several blazars. The implied single emission region in PMN J0948+0022 might reflect a difference of jets between RL-NLSy1s and blazars.

  7. Inner jet kinematics and the viewing angle towards the γ-ray narrow-line Seyfert 1 galaxy 1H 0323+342

    NASA Astrophysics Data System (ADS)

    Fuhrmann, Lars; Karamanavis, Vassilis; Komossa, Stefanie; Angelakis, Emmanouil; Krichbaum, Thomas P.; Schulz, Robert; Kreikenbohm, Annika; Kadler, Matthias; Myserlis, Ioannis; Ros, Eduardo; Nestoras, Ioannis; Zensus, J. Anton

    2016-11-01

    Near-Eddington accretion rates onto low-mass black holes are thought to be a prime driver of the multi-wavelength properties of the narrow-line Seyfert 1 (NLS1) population of active galactic nuclei (AGNs). Orientation effects have repeatedly been considered as another important factor involved, but detailed studies have been hampered by the lack of measured viewing angles towards this type of AGN. Here we present multi-epoch, 15 GHz VLBA images (MOJAVE program) of the radio-loud and Fermi/LAT-detected NLS1 galaxy 1H 0323+342. These are combined with single-dish, multi-frequency radio monitoring of the source's variability, obtained with the Effelsberg 100-m and IRAM 30-m telescopes, in the course of the F-GAMMA program. The VLBA images reveal six components with apparent speeds of ∼ 1–7 c, and one quasi-stationary feature. Combining the obtained apparent jet speed (β app) and variability Doppler factor (D var) estimates together with other methods, we constrain the viewing angle θ towards 1H 0323+342 to θ ≤ 4°–13°. Using literature values of βapp and D var, we also deduce a viewing angle of ≤ 8°–9° towards another radio- and γ-ray-loud NLS1, namely SBS 0846+513.

  8. To be or not to be a blazar. The case of the narrow-line Seyfert 1 SBS 0846+513

    NASA Astrophysics Data System (ADS)

    D'Ammando, F.; Orienti, M.; Finke, J.; Fermi-LAT Collaboration

    2012-12-01

    The presence of a relativistic jet in some radio-loud Narrow-Line Seyfert 1s (NLSy1) galaxies, first suggested by their variable radio emission and the flat radio spectra, is now confirmed by the Fermi-LAT detection of five NLSy1s in γ rays. In particular, a strong γ-ray flare from SBS 0846+513 was observed in 2011 June by Fermi-LAT reaching a γ-ray luminosity (0.1-300 GeV) of ~1048 erg s-1, comparable to that of bright flat spectrum radio quasars. Apparent superluminal velocity in the jet was inferred from 2011-2012 VLBA images, suggesting the presence of a highly relativistic jet. Both the power released by this object during the flaring activity and the apparent superluminal velocity are strong indicators of the presence of a relativistic jet as powerful as those in blazars. In addition, variability and spectral properties in radio and γ-ray bands indicate a blazar-like behaviour, suggesting that, except for some distinct optical characteristics, SBS 0846+513 could be considered as a young blazar at the low end of the blazar's black hole mass distribution.

  9. VARIABLE REDDENING AND BROAD ABSORPTION LINES IN THE NARROW-LINE SEYFERT 1 GALAXY WPVS 007: AN ORIGIN IN THE TORUS

    SciTech Connect

    Leighly, Karen M.; Cooper, Erin; Grupe, Dirk; Terndrup, Donald M.; Komossa, S.

    2015-08-10

    We report the discovery of an occultation event in the low-luminosity narrow-line Seyfert 1 galaxy WPVS 007 in 2015 February and March. In concert with longer timescale variability, these observations place strong constraints on the nature and location of the absorbing material. Swift monitoring has revealed a secular decrease since ∼2010 accompanied by flattening of the optical and UV photometry that suggests variable reddening. Analysis of four Hubble Space Telescope COS observations since 2010, including a Director’s Discretionary time observation during the occultation, shows that the broad-absorption-line velocity offset and the C iv emission-line width both decrease as the reddening increases. The occultation dynamical timescale, the BAL variability dynamical timescale, and the density of the BAL gas show that both the reddening material and the broad-absorption-line gas are consistent with an origin in the torus. These observations can be explained by a scenario in which the torus is clumpy with variable scale height, and the BAL gas is blown from the torus material like spray from the crest of a wave. As the obscuring material passes into our line of sight, we alternately see high-velocity broad absorption lines and a clear view to the central engine, or low-velocity broad absorption lines and strong reddening. WPVS 007 has a small black hole mass, and correspondingly short timescales, and so we may be observing behavior that is common in BALQSOs, but is not typically observable.

  10. VERY LONG BASELINE ARRAY IMAGING OF PARSEC-SCALE RADIO EMISSIONS IN NEARBY RADIO-QUIET NARROW-LINE SEYFERT 1 GALAXIES

    SciTech Connect

    Doi, Akihiro; Asada, Keiichi; Inoue, Makoto; Fujisawa, Kenta; Nagai, Hiroshi; Hagiwara, Yoshiaki; Wajima, Kiyoaki

    2013-03-01

    We conducted Very Long Baseline Array (VLBA) observations of seven nearby narrow-line Seyfert 1 (NLS1) galaxies at 1.7 GHz ({lambda}18 cm) with milliarcsecond resolution. This is the first systematic very long baseline interferometry study focusing on the central parsec-scale regions of radio-quiet NLS1s. Five of the seven were detected at a brightness temperature of {approx}> 5 Multiplication-Sign 10{sup 6} K and contain radio cores with high brightness temperatures of >6 Multiplication-Sign 10{sup 7} K, indicating a nonthermal process driven by jet-producing central engines as in radio-loud NLS1s and other active galactic nucleus classes. VLBA images of MRK 1239, MRK 705, and MRK 766 exhibit parsec-scale jets with clear linear structures. A large portion of the radio power comes from diffuse emission components that are distributed within the nuclear regions ({approx}< 300 pc), which is a common characteristic throughout the observed NLS1s. Jet kinetic powers limited by the Eddington limit may be insufficient to allow the jets to escape to kiloparsec scales for these radio-quiet NLS1s with low-mass black holes of {approx}< 10{sup 7} M {sub Sun }.

  11. DISCOVERY OF DRAMATIC OPTICAL VARIABILITY IN SDSS J1100+4421: A PECULIAR RADIO-LOUD NARROW-LINE SEYFERT 1 GALAXY?

    SciTech Connect

    Tanaka, Masaomi; Morokuma, Tomoki; Doi, Mamoru; Kikuchi, Yuki; Itoh, Ryosuke; Akitaya, Hiroshi; Tanaka, Yasuyuki T.; Kawabata, Koji S.; Tominaga, Nozomu; Saito, Yoshihiko; Kawai, Nobuyuki; Stawarz, Łukasz; Gandhi, Poshak; Ali, Gamal; Essam, Ahmad; Hamed, Gamal; Aoki, Tsutomu; Contreras, Carlos; Hsiao, Eric Y.; Iwata, Ikuru; and others

    2014-10-01

    We present our discovery of dramatic variability in SDSS J1100+4421 by the high-cadence transient survey Kiso Supernova Survey. The source brightened in the optical by at least a factor of three within about half a day. Spectroscopic observations suggest that this object is likely a narrow-line Seyfert 1 galaxy (NLS1) at z = 0.840, however, with unusually strong narrow emission lines. The estimated black hole mass of ∼10{sup 7} M {sub ☉} implies bolometric nuclear luminosity close to the Eddington limit. SDSS J1100+4421 is also extremely radio-loud, with a radio loudness parameter of R ≅ 4 × 10{sup 2}-3 × 10{sup 3}, which implies the presence of relativistic jets. Rapid and large-amplitude optical variability of the target, reminiscent of that found in a few radio- and γ-ray-loud NLS1s, is therefore produced most likely in a blazar-like core. The 1.4 GHz radio image of the source shows an extended structure with a linear size of about 100 kpc. If SDSS J1100+4421 is a genuine NLS1, as suggested here, this radio structure would then be the largest ever discovered in this type of active galaxies.

  12. X-RAY HIGH-RESOLUTION SPECTROSCOPY REVEALS FEEDBACK IN A SEYFERT GALAXY FROM AN ULTRA-FAST WIND WITH COMPLEX IONIZATION AND VELOCITY STRUCTURE

    SciTech Connect

    Longinotti, A. L.; Krongold, Y.; Guainazzi, M.; Santos-Lleo, M.; Rodriguez-Pascual, P.; Giroletti, M.; Panessa, F.; Costantini, E.

    2015-11-10

    Winds outflowing from active galactic nuclei (AGNs) may carry significant amounts of mass and energy out to their host galaxies. In this paper we report the detection of a sub-relativistic outflow observed in the narrow line Seyfert 1 galaxy IRAS 17020+4544 as a series of absorption lines corresponding to at least five absorption components with an unprecedented wide range of associated column densities and ionization levels and velocities in the range of 23,000–33,000 km s{sup −1}, detected at X-ray high spectral resolution (E/ΔE ∼ 1000) with the ESA's observatory XMM-Newton. The charge states of the material constituting the wind clearly indicate a range of low to moderate ionization states in the outflowing gas and column densities that are significantly lower than observed in highly ionized ultra-fast outflows. We estimate that at least one of the outflow components may carry sufficient energy to substantially suppress star formation and heat the gas in the host galaxy. IRAS 17020+4544 therefore provides an interesting example of feedback by a moderately luminous AGN that is hosted in a spiral galaxy, a case barely envisaged in most evolution models, which often predict that feedback processes take place in massive elliptical galaxies hosting luminous quasars in a post-merger phase.

  13. The Seyfert 2 Galaxy NGC 2110: Hard X-Ray Emission Observed by NuStar and Variability of the Iron K-Alpha Line

    NASA Technical Reports Server (NTRS)

    Marinucci, A.; Matt, G.; Bianchi, S.; Lu, T. N.; Arevalo, P.; Balokovic, M.; Ballantyne, D.; Bauer, F. E.; Boggs, S. E.; Stern, D.; Zhang, William W.

    2014-01-01

    We present NuSTAR observations of the bright Seyfert 2 galaxy NGC 2110 obtained in 2012, when the source was at the highest flux level ever observed, and in 2013, when the source was at a more typical flux level. We include archival observations from other X-ray satellites, namely XMM-Newton, Suzaku, BeppoSAX, Chandra and Swift. Simultaneous NuSTAR and Swift broad band spectra (in the 3-80 keV range) indicate a cutoff energy E(sub c) greater than 210 keV, with no detectable contribution from Compton reflection. NGC 2110 is one of the very few sources where no evidence for distant Compton thick scattering is found and, by using temporal information collected over more than a decade, we investigate variations of the iron K(alpha) line on time scales of years. The Fe K alpha line is likely the sum of two components: one constant (originating from distant Compton-thick material) and the other one variable and linearly correlated with the source flux (possibly arising from Compton-thin material much closer to the black hole).

  14. VizieR Online Data Catalog: [OIII] of radio-emitting narrow-line Seyfert 1 (Berton+, 2016)

    NASA Astrophysics Data System (ADS)

    Berton, M.; Foschini, L.; Ciroi, S.; Cracco, V.; La Mura, G.; di Mille, F.; Rafanelli, P.

    2016-08-01

    We decided to use the sample created by Cracco et al. (2016, MNRAS, submitted) to have a uniformly selected sample of RQNLS1s that is not contaminated by any spurious source. They found 9 RLNLS1s, which we included in our second sample, and 59 RQNLS1s. To further increase the number of sources, we decided to add also the RQNLS1s from Berton et al. (2015A&A...578A..28B), which were not already included in their sample because of the selection criteria and had a suitable spectra to analyze. Our RQNLS1s sample in conclusion is made of 68 RQNLS1s. For the RLNLS1s sample, besides the nine sources we already found with the previous selection, we decided to use all the sources analyzed by Foschini et al. (2015A&A...575A..13F) and Berton et al. (2015A&A...578A..28B) for which an optical spectrum was available in SDSS DR12, in the NED archive, or observable with the Asiago 1.22m telescope (Sect. 3.1). Our sample is comprised of 56 RLNLS1s. (4 data files).

  15. Correlation Analysis of Optical and Radio Light Curves for a Large Sample of Active Galactic Nuclei

    NASA Astrophysics Data System (ADS)

    Clements, S. D.; Smith, A. G.; Aller, H. D.; Aller, M. F.

    1995-08-01

    The Rosemary Hill Observatory has accumulated internally consistent light curves extending over as much as 26 years for a large sample of active galactic nuclei. Forty-six of these optical records have been compared with similar radio records from the University of Michigan Radio Astronomy Observatory and the Algonquin Radio Observatory. For 18 objects, pairs of records were sufficiently long and unconfused to allow reliable application of the Discrete Correlation Function analysis; this group included 8 BL Lacertids, 8 quasars, and 2 Seyfert galaxies. Nine of the 18 sources showed positive radio-optical correlations, with the radio events lagging the optical by intervals ranging from 0 to 14 months. Consistent with the relativistic beaming model of the BL Lacertids, the group displaying correlations was dominated by this type of object.

  16. CALCULATING TIME LAGS FROM UNEVENLY SAMPLED LIGHT CURVES

    SciTech Connect

    Zoghbi, A.; Reynolds, C.; Cackett, E. M.

    2013-11-01

    Timing techniques are powerful tools to study dynamical astrophysical phenomena. In the X-ray band, they offer the potential of probing accretion physics down to the event horizon. Recent work has used frequency- and energy-dependent time lags as tools for studying relativistic reverberation around the black holes in several Seyfert galaxies. This was achieved due to the evenly sampled light curves obtained using XMM-Newton. Continuously sampled data are, however, not always available and standard Fourier techniques are not applicable. Here, building on the work of Miller et al., we discuss and use a maximum likelihood method to obtain frequency-dependent lags that takes into account light curve gaps. Instead of calculating the lag directly, the method estimates the most likely lag values at a particular frequency given two observed light curves. We use Monte Carlo simulations to assess the method's applicability and use it to obtain lag-energy spectra from Suzaku data for two objects, NGC 4151 and MCG-5-23-16, that had previously shown signatures of iron K reverberation. The lags obtained are consistent with those calculated using standard methods using XMM-Newton data.

  17. Fluorescent excitation of Fe 2, Mn 2, Ti 2, N 1 lines by V 4, N 5, O 6: Emission lines in the spectra of symbiotic stars and Seyfert galaxies

    NASA Technical Reports Server (NTRS)

    Gilra, D. P.

    1984-01-01

    Analysis of the published IUE and ground based high resolution spectra of symbiotic stars, particularly RR Tel, shows that the dominant excitation mechanism of Fe II, Mn II, Ti II, and N I lines is the selective fluorescent excitation of some levels by the strong C IV, N V, and O VI emission lines. The same mechanism should work for the excitation of Fe II lines in the spectra of Seyfert galaxies and Q60's whose emission spectra are quite similar to those of symbiotic stars. The similarities and differences between the fluroescent excitation mechanism reported herein and the Bowen's mechanism is analyzed.

  18. An Extreme, Blueshifted Iron-Line Profile in the Narrow-Line Seyfert 1 PG 1402+261: An Edge-on Accretion Disk or Highly Ionized Absorption?

    NASA Astrophysics Data System (ADS)

    Reeves, J. N.; Porquet, D.; Turner, T. J.

    2004-11-01

    We report on a short XMM-Newton observation of the radio-quiet narrow-line Seyfert 1 galaxy PG 1402+261. The EPIC X-ray spectrum of PG 1402+261 shows a strong excess of counts between 6 and 9 keV in the rest frame. This feature can be modeled by an unusually strong (equivalent width 2 keV) and very broad (FWHM velocity of 110,000 km s-1) iron K-shell emission line. The line centroid energy at 7.3 keV appears blueshifted with respect to the iron Kα emission band between 6.4 and 6.97 keV, while the blue wing of the line extends to 9 keV in the quasar rest frame. The line profile can be fitted by reflection from the inner accretion disk, but an inclination angle of >60° is required to model the extreme blue wing of the line. Furthermore, the extreme strength of the line requires a geometry whereby the hard X-ray emission from PG 1402+261 above 2 keV is dominated by the pure-reflection component from the disk, while little or none of the direct hard power law is observed. Alternatively, the spectrum above 2 keV may be explained by an ionized absorber, if the column density is sufficiently high (NH>3×1023 cm-2) and if the matter is ionized enough to produce a deep (τ~1) iron K-shell absorption edge at 9 keV. This absorber could originate in a large column density, high-velocity outflow, perhaps similar to those that appear to be observed in several other high accretion rate active galactic nuclei. Further observations, especially at higher spectral resolution, are required to distinguish between the accretion disk reflection and outflow scenarios.

  19. On the reality of broad iron L lines from the narrow line Seyfert 1 galaxies 1H0707–495 and IRAS 13224–3809

    NASA Astrophysics Data System (ADS)

    Karbhari Pawar, Pramod; Dewangan, Gulab Chand; Khushalrao Patil, Madhav; Misra, Ranjeev; Keshav Jogadand, Sharada

    2016-11-01

    We performed time resolved spectroscopy of 1H0707–495 and IRAS 13224–3809 using long XMM-Newton observations. These are strongly variable narrow line Seyfert 1 galaxies and show broad features around 1 keV that have been interpreted as relativistically broad Fe Lα lines. Such features are not clearly observed in other active galactic nuclei despite sometimes having high iron abundance required by the best fitted blurred reflection models. Given the importance of these lines, we explore whether the rapid variability of spectral parameters may introduce broad bumps/dips artificially in the time averaged spectrum, which may then be mistaken as broadened lines. We tested this hypothesis by performing time resolved spectroscopy using long (>100 ks) XMM-Newton observations and by dividing them into segments with typical exposures of a few ks. We extracted spectra from each such segment and modeled them using a two component phenomenological model consisting of a power law to represent the hard component and a black body to represent the soft emission. As expected, both the sources showed variations in the spectral parameters. Using these variation trends, we simulated model spectra for each segment and then co-added to get a combined simulated spectrum. In the simulated spectra, we found no broad features below 1 keV and in particular no deviation near 0.9 keV as seen in the real averaged spectra. This implies that the broad Fe Lα line that is seen in the spectra of these sources is not an artifact of the variation of spectral components and, hence, provides evidence that the line is indeed genuine.

  20. THE COMPTON-THICK SEYFERT 2 NUCLEUS OF NGC 3281: TORUS CONSTRAINTS FROM THE 9.7 {mu}m SILICATE ABSORPTION

    SciTech Connect

    Sales, Dinalva A.; Pastoriza, M. G.; Riffel, R.; Winge, C.

    2011-09-01

    We present mid-infrared (mid-IR) spectra of the Compton-thick Seyfert 2 galaxy NGC 3281, obtained with the Thermal-Region Camera Spectrograph at the Gemini-South telescope. The spectra present a very deep silicate absorption at 9.7 {mu}m, and [S IV] 10.5 {mu}m and [Ne II] 12.7 {mu}m ionic lines, but no evidence of polycyclic aromatic hydrocarbon emission. We find that the nuclear optical extinction is in the range 24 mag {<=} A{sub V} {<=} 83 mag. A temperature T = 300 K was found for the blackbody dust continuum component of the unresolved 65 pc nucleus and the region at 130 pc SE, while the region at 130 pc NW reveals a colder temperature (200 K). We describe the nuclear spectrum of NGC 3281 using a clumpy torus model that suggests that the nucleus of this galaxy hosts a dusty toroidal structure. According to this model, the ratio between the inner and outer radius of the torus in NGC 3281 is R{sub 0}/R{sub d} = 20, with 14 clouds in the equatorial radius with optical depth of {tau}{sub V} = 40 mag. We would be looking in the direction of the torus equatorial radius (i = 60{sup 0}), which has outer radius of R{sub 0} {approx} 11 pc. The column density is N{sub H} {approx} 1.2 x 10{sup 24} cm{sup -2} and the iron K{alpha} equivalent width ({approx}0.5-1.2 keV) is used to check the torus geometry. Our findings indicate that the X-ray absorbing column density, which classifies NGC 3281 as a Compton-thick source, may also be responsible for the absorption at 9.7 {mu}m providing strong evidence that the silicate dust responsible for this absorption can be located in the active galactic nucleus torus.

  1. Short-term radio variability and parsec-scale structure in A gamma-ray narrow-line Seyfert 1 galaxy 1H 0323+342

    SciTech Connect

    Wajima, Kiyoaki; Fujisawa, Kenta; Hayashida, Masaaki; Isobe, Naoki; Ishida, Takafumi; Yonekura, Yoshinori

    2014-02-01

    We made simultaneous single-dish and very long baseline interferometer (VLBI) observations of a narrow-line Seyfert 1 galaxy 1H 323+342, showing gamma-ray activity revealed by Fermi/Large Area Telescope observations. We found significant variation of the total flux density at 8 GHz on the timescale of one month by the single-dish monitoring. The total flux density varied by 5.5% in 32 days, which is comparable to the gamma-ray variability timescale, corresponding to the variability brightness temperature of 7.0 × 10{sup 11} K. The source consists of central and southeastern components on the parsec (pc) scale. Only the flux of the central component decreased in the same way as the total flux density, indicating that the short-term radio variability, and probably the gamma-ray-emitting region, is associated with this component. From the VLBI observations, we obtained brightness temperatures of greater than (5.2 ± 0.3) × 10{sup 10} K and derived an equipartition Doppler factor of greater than 1.7, a variability Doppler factor of 2.2, and an 8 GHz radio power of 10{sup 24.6} W Hz{sup –1}. Combining them, we conclude that acceleration of radio jets and creation of high-energy particles are ongoing in the central engine and that the apparent very radio-loud feature of the source is due to the Doppler boosting effect, resulting in the intrinsic radio loudness being an order of magnitude smaller than the observed values. We also conclude that the pc-scale jet represents recurrent activity from the spectral fitting and the estimated kinematic age of pc- and kpc-scale extended components with different position angles.

  2. Simultaneous UV and X-ray Spectroscopy of the Seyfert 1 Galaxy NGC 5548. I: Physical Conditions in the UV Absorbers

    NASA Technical Reports Server (NTRS)

    Crenshaw, D. M.; Kraemer, S. B.; Gabel, J. R.; Kaastra, J. S.; Steenbrugge, K. C.; Brinkman, A. C.; Dunn, J. P.; George, I. M.; Liedahl, D. A.; Paerels, F. B. S.

    2003-01-01

    We present new UV spectra of the nucleus of the Seyfert 1 galaxy NGC 5548, which we obtained with the Space Telescope Imaging Spectrograph at high spectral resolution, in conjunction with simultaneous Chandra X-ray Observatory spectra. Taking advantage of the low UV continuum and broad emission-line fluxes, we have determined that the deepest UV absorption component covers at least a portion of the inner, high-ionization narrow-line region (NLR). We find nonunity covering factors in the cores of several kinematic components, which increase the column density measurements of N V and C IV by factors of 1.2 to 1.9 over the full-covering case; however, the revised columns have only a minor effect on the parameters derived from our photoionization models. For the first time, we have simultaneous N V and C IV columns for component 1 (at -1040 km/s), and find that this component cannot be an X-ray warm absorber, contrary to our previous claim based on nonsimultaneous observations. We find that models of the absorbers based on solar abundances severely overpredict the O VI columns previously obtained with the Far Ultraviolet Spectrograph, and present arguments that this is not likely due to variability. However, models that include either enhanced nitrogen (twice solar) or dust, with strong depletion of carbon in either case, are successful in matching all of the observed ionic columns. These models result in substantially lower ionization parameters and total column densities compared to dust-free solar-abundance models, and produce little O VII or O VIII, indicating that none of the UV absorbers are X-ray warm absorbers.

  3. The host galaxy of a narrow-line Seyfert 1 galaxy, RE J1034+396, with X-ray quasi-periodic oscillations

    NASA Astrophysics Data System (ADS)

    Bian, Wei-Hao; Huang, Kai

    2010-01-01

    Using simple stellar population synthesis, we model the bulge stellar contribution in the optical spectrum of a narrow-line Seyfert 1 galaxy, RE J1034+396. We find that its bulge stellar velocity dispersion is 67.7 +/- 8 kms-1. The supermassive black hole (SMBH) mass is about (1-4) × 106 Msolar if it follows the well-known MBH-σ* relation found in quiescent galaxies. We also derive the SMBH mass from the Hβ second moment, which is consistent with that from its bulge stellar velocity dispersion. The SMBH mass of (1-4) × 106 Msolar implies that the X-ray quasi-periodic oscillation (QPO) of RE J1034+396 can be scaled to a high-frequency QPO at 27-108 Hz found in Galactic black hole binaries with a 10-Msolar black hole. With the mass distribution in different age stellar populations, we find that the mean specific star formation rate (SSFR) over the past 0.1 Gyr is 0.0163 +/- 0.0011 Gyr-1, the stellar mass in the logarithm is 10.155 +/- 0.06 in units of solar mass and the current star formation rate is 0.23 +/- 0.016 Msolaryr-1. For RE J1034+396, there is no relation between the Eddington ratio and the SSFR as suggested by Chen et al., despite a larger scatter in their relation. We also suggest that about 7.0 per cent of the total Hα luminosity and 50 per cent of the total [OII] luminosity come from the star formation process.

  4. CORONAL PROPERTIES OF THE SEYFERT 1.9 GALAXY MCG-05-23-016 DETERMINED FROM HARD X-RAY SPECTROSCOPY WITH NuSTAR

    SciTech Connect

    Baloković, M.; Harrison, F. A.; Esmerian, C. J.; Fürst, F.; Walton, D. J.; Matt, G.; Marinucci, A.; Zoghbi, A.; Reynolds, C. S.; Ballantyne, D. R.; Boggs, S. E.; Craig, W. W.; Christensen, F. E.; Fabian, A. C.; Parker, M. L.; Hailey, C. J.; Stern, D.; Zhang, W. W.

    2015-02-10

    Measurements of the high-energy cut-off in the coronal continuum of active galactic nuclei have long been elusive for all but a small number of the brightest examples. We present a direct measurement of the cut-off energy in the nuclear continuum of the nearby Seyfert 1.9 galaxy MCG-05-23-016 with unprecedented precision. The high sensitivity of NuSTAR up to 79 keV allows us to clearly disentangle the spectral curvature of the primary continuum from that of its reflection component. Using a simple phenomenological model for the hard X-ray spectrum, we constrain the cut-off energy to 116{sub −5}{sup +6} keV with 90% confidence. Testing for more complex models and nuisance parameters that could potentially influence the measurement, we find that the cut-off is detected robustly. We further use simple Comptonized plasma models to provide independent constraints for both the kinetic temperature of the electrons in the corona and its optical depth. At the 90% confidence level, we find kT{sub e} = 29 ± 2 keV and τ {sub e} = 1.23 ± 0.08 assuming a slab (disk-like) geometry, and kT{sub e} = 25 ± 2 keV and τ {sub e} = 3.5 ± 0.2 assuming a spherical geometry. Both geometries are found to fit the data equally well and their two principal physical parameters are correlated in both cases. With the optical depth in the τ {sub e} ≳ 1 regime, the data are pushing the currently available theoretical models of the Comptonized plasma to the limits of their validity. Since the spectral features and variability arising from the inner accretion disk have been observed previously in MCG-05-23-016, the inferred high optical depth implies that a spherical or disk-like corona cannot be homogeneous.

  5. Accretion disc-corona and jet emission from the radio-loud narrow-line Seyfert 1 galaxy RX J1633.3+4719

    NASA Astrophysics Data System (ADS)

    Mallick, Labani; Dewangan, G. C.; Gandhi, P.; Misra, R.; Kembhavi, A. K.

    2016-08-01

    We perform X-ray/ultraviolet (UV) spectral and X-ray variability studies of the radio-loud narrow-line Seyfert 1 (NLS1) galaxy RX J1633.3+4719 using XMM-Newton and Suzaku observations from 2011 and 2012. The 0.3-10 keV spectra consist of an ultrasoft component described by an accretion disc blackbody (kT_in = 39.6^{+11.2}_{-5.5} eV) and a power law due to the thermal Comptonization (Γ = 1.96^{+0.24}_{-0.31}) of the disc emission. The disc temperature inferred from the soft excess is at least a factor of 2 lower than that found for the canonical soft excess emission from radio-quiet NLS1s. The UV spectrum is described by a power law with photon index 3.05^{+0.56}_{-0.33}. The observed UV emission is too strong to arise from the accretion disc or the host galaxy, but can be attributed to a jet. The X-ray emission from RX J1633.3+4719 is variable with fractional variability amplitude Fvar = 13.5 ± 1.0 per cent. In contrast to radio-quiet active galactic nuclei (AGN), X-ray emission from the source becomes harder with increasing flux. The fractional rms variability increases with energy and the rms spectrum is well described by a constant disc component and a variable power-law continuum with the normalization and photon index being anticorrelated. Such spectral variability cannot be caused by variations in the absorption and must be intrinsic to the hot corona. Our finding of possible evidence for emission from the inner accretion disc, jet and hot corona from RX J1633.3+4719 in the optical to X-ray bands makes this object an ideal target to probe the disc-jet connection in AGN.

  6. Canada-France Redshift Survey - X. The quasar sample

    NASA Astrophysics Data System (ADS)

    Schade, David; Crampton, David; Hammer, F.; Le Fevre, O.; Lilly, S. J.

    1996-01-01

    Six objects with broad emission lines and redshifts from 0.48 to 2.07 were discovered among 736 extragalactic objects in the Canada-France Redshift Survey (CFRS). Although the luminosities of half of the objects are such that they are in the Seyfert regime (M_B<~-23), all would be designated as quasars in traditional surveys. Since the only selection criterion was that 17.5<=I_AB<=22.5, or approximately B<23 (assuming a continuum power-law slope alpha=-0.5), these quasars represent an unbiased, flux-limited sample. Although uncertain, the implied surface density, 200^-120-80 deg^-2, is the highest yet measured, and is in good agreement with extrapolations from other faint surveys and the evolving luminosity function models of Boyle. The distributions of the continuum properties, emission-line strengths, etc. of the quasars do not differ significantly from those of quasars selected by other means, and therefore they would have been detected in most traditional surveys. Three of the quasars may be associated with clusters or large structures of galaxies at z<~1.

  7. Resolving the Large Scale Spectral Variability of the Luminous Seyfert 1 Galaxy 1H 0419-577: Evidence for a New Emission Component and Absorption by Cold Dense Matter

    NASA Technical Reports Server (NTRS)

    Pounds, K. A.; Reeves, J. N.; Page, K. L.; OBrien, P. T.

    2004-01-01

    An XMM-Newton observation of the luminous Seyfert 1 galaxy 1H 0419-577 in September 2002, when the source was in an extreme low-flux state, found a very hard X-ray spectrum at 1-10 keV with a strong soft excess below -1 keV. Comparison with an earlier XMM-Newton observation when 1H 0419-577 was X-ray bright indicated the dominant spectral variability was due to a steep power law or cool Comptonised thermal emission. Four further XMM-Newton observations, with 1H 0419-577 in intermediate flux states, now support that conclusion, while we also find the variable emission component in intermediate state difference spectra to be strongly modified by absorption in low ionisation matter. The variable soft excess then appears to be an artefact of absorption of the underlying continuum while the core soft emission can be attributed to re- combination in an extended region of more highly ionised gas. We note the wider implications of finding substantial cold dense matter overlying (or embedded in) the X-ray continuum source in a luminous Seyfert 1 galaxy.

  8. STRONG UV AND X-RAY VARIABILITY OF THE NARROW LINE SEYFERT 1 GALAXY WPVS 007-ON THE NATURE OF THE X-RAY LOW STATE

    SciTech Connect

    Grupe, Dirk; Barlow, Brad N.; Komossa, S.; Scharwaechter, Julia; Dietrich, Matthias; Leighly, Karen M.; Lucy, Adrian E-mail: julia.scharwaechter@obspm.fr

    2013-10-01

    We report on multi-wavelength observations of the X-ray transient Narrow Line Seyfert 1 (NLS1) galaxy WPVS 007. The galaxy was monitored with Swift between 2005 October and 2013 July, after it had previously undergone a dramatic drop in its X-ray flux. For the first time, we are able to repeatedly detect this NLS1 in X-rays again. This increased number of detections in the last couple of years may suggest that the strong absorber that has been found in this active galactic nucleus (AGN) is starting to become leaky and may eventually disappear. The X-ray spectra obtained for WPVS 007 are all consistent with a partial covering absorber model. A spectrum based on the data during the extreme low X-ray flux states shows that the absorption column density is of the order of 4 Multiplication-Sign 10{sup 23} cm{sup -2} with a covering fraction of 95%. WPVS 007 also displays one of the strongest UV variabilities seen in NLS1s. The UV continuum variability anti-correlates with the optical/UV slope {alpha}{sub UV}, which suggests that the variability may be primarily due to reddening. The UV variability timescales are consistent with moving dust ''clouds'' located beyond the dust sublimation radius of R{sub sub} Almost-Equal-To 20 lt-days. We present for the first time near-infrared JHK data of WPVS 007, which reveal a rich emission-line spectrum. Recent optical spectroscopy does not indicate significant variability in the broad permitted and Fe II emission lines, implying that the ionizing continuum seen by those gas clouds has not significantly changed over the last decades. All X-ray and UV observations are consistent with a scenario in which an evolving broad absorption line (BAL) flow obscures the continuum emission. As such, WPVS 007 is an important target for our understanding of BAL flows in low-mass AGNs.

  9. The First GeV Outburst of the Radio-loud Narrow-line Seyfert 1 Galaxy PKS 1502+036

    NASA Astrophysics Data System (ADS)

    Paliya, Vaidehi S.; Stalin, C. S.

    2016-03-01

    The γ-ray-loud narrow-line Seyfert 1 (γ-NLSy1) galaxy PKS 1502+036 (z = 0.409) exhibited its first γ-ray outburst on 2015 December 20. In the energy range of 0.1-300 GeV, the highest flux measured by the Fermi-Large Area Telescope is (3.90 ± 1.52) × 10-6 {ph} {{cm}}-2 {{{s}}}-1, which is the highest γ-ray flux ever detected from this object. The associated spectral shape is soft (Γ0.1-300 GeV = 2.57 ± 0.17) and this corresponds to an isotropic γ-ray luminosity of (1.2 ± 0.6) × 1048 erg s-1. We generate the broadband spectral energy distribution (SED) during the GeV flare and reproduce it using a one-zone leptonic emission model. The optical-UV spectrum can be explained by a combination of synchrotron and accretion disk emission, whereas the X-ray-to-γ-ray SED can be satisfactorily reproduced by inverse-Compton scattering of thermal photons that originated from the torus. The derived SED parameters hint that the increase in the bulk Lorentz factor is a major cause of the flare and the location of the emission region is estimated as being outside the broad-line region but still inside the torus. A comparison of the GeV-flaring SED of PKS 1502+036 with that of two other γ-NLSy1 galaxies, namely, 1H 0323+342 (z = 0.061) and PMN J0948+0022 (z = 0.585), and also with flat spectrum radio quasar (FSRQ) 3C 279 (z = 0.536), has led to the conclusion that the GeV-flaring SEDs of γ-NLSy1 galaxies resemble FSRQs and a major fraction of their bolometric luminosities are emitted at γ-ray energies.

  10. High-resolution X-ray spectroscopy of the Seyfert 1 Mrk 841: insights into the warm absorber and warm emitter

    NASA Astrophysics Data System (ADS)

    Longinotti, A. L.; Costantini, E.; Petrucci, P. O.; Boisson, C.; Mouchet, M.; Santos-Lleo, M.; Matt, G.; Ponti, G.; Gonçalves, A. C.

    2010-02-01

    Context. The Seyfert 1 galaxy Mrk 841 was observed five times between 2001 and 2005 by the XMM-Newton X-ray observatory. The source is well known for showing spectral complexity in the variable iron line and in the soft X-ray excess. Aims: The availability of multiple exposures obtained by the reflection grating spectrometer (RGS) cameras allows thorough study of the complex absorption and emission spectral features in the soft X-ray band. This paper reports on the first study of Mrk 841 soft X-ray spectrum at high spectral resolution. Methods: The three combined exposures obtained in January 2001 and the two obtained in January and July 2005 were analysed with the SPEX software. Results: We detect a two-phase warm absorber. A medium ionisation component (log ξ ~ 1.5-2.2 erg s cm-1) is responsible for a deep absorption feature in the unresolved transition array of the Fe M-shell and for several absorption lines in the OVI-VIII band, and a higher ionisation phase with log ξ ~ 3 erg s cm-1 is required to fit absorption in the NeIX-X band. The ionisation state and the column density of the gas present moderate variation from 2001 to 2005 for both phases. The high ionisation component of the warm absorber has no effect on the Fe K band. No significant velocity shift of the absorption lines is measured in the RGS data. Remarkably, the 2005 spectra show emission features consistent with photoionisation in a high-density (ne ≥ 1011 cm-3) gas. A prominent OVII line triplet was clearly observed in January 2005 and narrow radiative recombination continua (RRC) of OVII and CVI were observed in both 2005 data sets. A broad Gaussian line around 21.7 Å was also required to fit all the data sets. The derived radial distance for the emission lines seems to suggest that the photoionisation takes place within the optical broad line region of the source.

  11. X-Ray and Optical Correlation of Type I Seyfert NGC 3516 Studied with Suzaku and Japanese Ground-based Telescopes

    NASA Astrophysics Data System (ADS)

    Noda, Hirofumi; Minezaki, Takeo; Watanabe, Makoto; Kokubo, Mitsuru; Kawaguchi, Kenji; Itoh, Ryosuke; Morihana, Kumiko; Saito, Yoshihiko; Nakao, Hikaru; Imai, Masataka; Moritani, Yuki; Takaki, Katsutoshi; Kawabata, Miho; Nakaoka, Tatsuya; Uemura, Makoto; Kawabata, Koji; Yoshida, Michitoshi; Arai, Akira; Takagi, Yuhei; Morokuma, Tomoki; Doi, Mamoru; Itoh, Yoichi; Yamada, Shin'ya; Nakazawa, Kazuhiro; Fukazawa, Yasushi; Makishima, Kazuo

    2016-09-01

    From 2013 April to 2014 April, we performed X-ray and optical simultaneous monitoring of the type 1.5 Seyfert galaxy NGC 3516. We employed Suzaku and five Japanese ground-based telescopes—the Pirka, Kiso Schmidt, Nayuta, MITSuME, and the Kanata telescopes. The Suzaku observations were conducted seven times with various intervals ranging from days or weeks to months, with an exposure of ˜50 ks each. The optical B-band observations not only covered those of Suzaku almost simultaneously, but also followed the source as frequently as possible. As a result, NGC 3516 was found in its faint phase with a 2-10 keV flux of 0.21-2.70 × 10-11 erg s-1 cm-2. The 2-45 keV X-ray spectra were composed of a dominant variable hard power-law (PL) continuum with a photon index of ˜1.7 and a non-relativistic reflection component with a prominent Fe-Kα emission line. Producing the B-band light curve by differential image photometry, we found that the B-band flux changed by ˜2.7 × 10-11 erg s-1 cm-2, which is comparable to the X-ray variation, and we detected a significant flux correlation between the hard PL component in X-rays and the B-band radiation, for the first time in NGC 3516. By examining their correlation, we found that the X-ray flux preceded that in the B band by {2.0}-0.6+0.7 days (1σ error). Although this result supports the X-ray reprocessing model, the derived lag is too large to be explained by the standard view, which assumes a “lamppost”-type X-ray illuminator located near a standard accretion disk. Our results are better explained by assuming a hot accretion flow and a truncated disk.

  12. Simultaneous XMM-Newton and HST-COS observation of 1H 0419-577. II. Broadband spectral modeling of a variable Seyfert galaxy

    NASA Astrophysics Data System (ADS)

    Di Gesu, L.; Costantini, E.; Piconcelli, E.; Ebrero, J.; Mehdipour, M.; Kaastra, J. S.

    2014-03-01

    In this paper, we present the longest exposed (97 ks) XMM-Newton EPIC-pn spectrum ever obtained for the Seyfert 1.5 galaxy1H 0419-577. With the aim of explaining the broadband emission of this source, we took advantage of the simultaneous coverage in the optical/UV that was provided in the present case by the XMM-Newton Optical Monitor and by a HST-COS observation. Archival FUSE flux measurements in the far-ultraviolet were also used for the present analysis. We successfully modeled the X-ray spectrum and the optical/UV fluxes data points using a Comptonization model. We found that a blackbody temperature of T ~ 56 eV accounts for the optical/UV emission originating in the accretion disk. This temperature serves as an input for the Comptonized components that model the X-ray continuum. Both a warm (Twc ~ 0.7 keV, τwc ~ 7) and a hot corona (Thc ~ 160 keV, τhc ~ 0.5) intervene to upscatter the disk photons to X-ray wavelengths. With the addition of a partially covering (Cv ~ 50%) cold absorber with a variable opacity ( NH~ [1019-1022] cm-2), this model can also explain the historical spectral variability of this source, with the present dataset presenting the lowest one ( NH~1019 cm-2). We discuss a scenario where the variable absorber becomes less opaque in the highest flux states because it gets ionized in response to the variations of the X-ray continuum. The lower limit for the absorber density derived in this scenario is typical for the broad line region clouds. We infer that1H 0419-577may be viewed from an intermediate inclination angle i ≥ 54°, and, on this basis, we speculate that the X-ray obscuration may be associated with the innermost dust-free region of the obscuring torus. Finally, we critically compare this scenario with all the different models (e.g., disk reflection) that have been used in the past to explain the variability of this source.

  13. Near-infrared continuum and 3.3 micrometer(s) polycyclic aromatic hydrocarbon imaging of the starburst ring in the type 1 Seyfert galaxy NGC 7469

    NASA Technical Reports Server (NTRS)

    Mazzarella, J. M.; Voit, G. M.; Soifer, B. T.; Matthews, K.; Graham, J. R.; Armus, L.; Shupe, D.

    1994-01-01

    High resolution near-infrared images of the type 1 Seyfert galaxy NGC 7469 have been obtained to probe its dusty nuclear environment. Direct J, H, and K images are relatively featureless, but residual images created by subtracting a smooth model based on best-fitting elliptical isophotes reveal a tight inner spiral whose high surface-brightness portions correspond to a previously detected 3 sec (1 kpc) diameter ring of radio continuum emission. The inner infrared spiral arms extended approximately equal to 4 sec NW and SE from the nucleus, and the NW arm joins up with large-scale spiral structure visible in the R band. The residual images also show a bar-like structure aligned with the brightest infrared/radio hotspots at PA approximately equal to 50 deg. Three infrared hotspots are detected which align remarkably well with 6 cm radio continuum sources. The near-infrared ring and the hotspots are visible in the residual images, and in a high-resolution direct K-band image restored to an effective resolution of 0.65 sec (FWHM) using the Richardson-Lucy algorithm. The infrared hotspots have luminosities of nuL(sub nu) (2.2 micrometer(s)) approximately equal to 10(exp 8) solar luminosity (M(sub k) approximately equal to -16 mag), suggesting they are either giant H II regions or individual supernovae. The two brightest regions may be associated with enhanced star formation triggered by orbit crowding of gas where spiral arms emerge from an inner bar. Narrowband (delta lambda/lambda approximately 1.5%) imaging in the 3.28 micrometer(s) dust emission feature and surrounding continuum confirms the 3 sec diameter 3.28 micrometer(s) emission region detected previously using multiaperture photometry. The extended polycyclic aromatic hydrocarbon (PAH) emission is slightly elongated and aligned with published 1O III1 line emission and 12.5 micrometer(s) continuum emission, apparently tracing the starburst. The presence of approximately equal to 25% of the total 3.28 micrometer

  14. THE RISE OF AN IONIZED WIND IN THE NARROW-LINE SEYFERT 1 GALAXY Mrk 335 OBSERVED BY XMM-NEWTON AND HST

    SciTech Connect

    Longinotti, A. L.; Krongold, Y.; Kriss, G. A.; Ely, J.; Gallo, L.; Grupe, D.; Komossa, S.; Mathur, S.; Pradhan, A.

    2013-04-01

    We present the discovery of an outflowing ionized wind in the Seyfert 1 galaxy Mrk 335. Despite having been extensively observed by most of the largest X-ray observatories in the last decade, this bright source was not known to host warm absorber gas until recent XMM-Newton observations in combination with a long-term Swift monitoring program have shown extreme flux and spectral variability. High-resolution spectra obtained by the XMM-Newton Reflection Grating Spectrometer (RGS) detector reveal that the wind consists of three distinct ionization components, all outflowing at a velocity of {approx}5000 km s{sup -1}. This wind is clearly revealed when the source is observed at an intermediate flux state (2-5 Multiplication-Sign 10{sup -12} erg cm{sup -2} s{sup -1}). The analysis of multi-epoch RGS spectra allowed us to compare the absorber properties at three very different flux states of the source. No correlation between the warm absorber variability and the X-ray flux has been determined. The two higher ionization components of the gas (log {xi} {approx} 2.3 and 3.3) may be consistent with photoionization equilibrium, but we can exclude this for the only ionization component that is consistently present in all flux states (log {xi} {approx} 1.8). We have included archival, non-simultaneous UV data from Hubble Space Telescope (FOS, STIS, COS) with the aim of searching for any signature of absorption in this source that so far was known for being absorption-free in the UV band. In the Cosmic Origins Spectrograph (COS) spectra obtained a few months after the X-ray observations, we found broad absorption in C IV lines intrinsic to the active galactic nucleus and blueshifted by a velocity roughly comparable to the X-ray outflow. The global behavior of the gas in both bands can be explained by variation of the covering factor and/or column density, possibly due to transverse motion of absorbing clouds moving out of the line of sight at broad line region scale.

  15. X-Ray and Optical Correlation of Type I Seyfert NGC 3516 Studied with Suzaku and Japanese Ground-based Telescopes

    NASA Astrophysics Data System (ADS)

    Noda, Hirofumi; Minezaki, Takeo; Watanabe, Makoto; Kokubo, Mitsuru; Kawaguchi, Kenji; Itoh, Ryosuke; Morihana, Kumiko; Saito, Yoshihiko; Nakao, Hikaru; Imai, Masataka; Moritani, Yuki; Takaki, Katsutoshi; Kawabata, Miho; Nakaoka, Tatsuya; Uemura, Makoto; Kawabata, Koji; Yoshida, Michitoshi; Arai, Akira; Takagi, Yuhei; Morokuma, Tomoki; Doi, Mamoru; Itoh, Yoichi; Yamada, Shin’ya; Nakazawa, Kazuhiro; Fukazawa, Yasushi; Makishima, Kazuo

    2016-09-01

    From 2013 April to 2014 April, we performed X-ray and optical simultaneous monitoring of the type 1.5 Seyfert galaxy NGC 3516. We employed Suzaku and five Japanese ground-based telescopes—the Pirka, Kiso Schmidt, Nayuta, MITSuME, and the Kanata telescopes. The Suzaku observations were conducted seven times with various intervals ranging from days or weeks to months, with an exposure of ∼50 ks each. The optical B-band observations not only covered those of Suzaku almost simultaneously, but also followed the source as frequently as possible. As a result, NGC 3516 was found in its faint phase with a 2–10 keV flux of 0.21–2.70 × 10‑11 erg s‑1 cm‑2. The 2–45 keV X-ray spectra were composed of a dominant variable hard power-law (PL) continuum with a photon index of ∼1.7 and a non-relativistic reflection component with a prominent Fe–Kα emission line. Producing the B-band light curve by differential image photometry, we found that the B-band flux changed by ∼2.7 × 10‑11 erg s‑1 cm‑2, which is comparable to the X-ray variation, and we detected a significant flux correlation between the hard PL component in X-rays and the B-band radiation, for the first time in NGC 3516. By examining their correlation, we found that the X-ray flux preceded that in the B band by {2.0}-0.6+0.7 days (1σ error). Although this result supports the X-ray reprocessing model, the derived lag is too large to be explained by the standard view, which assumes a “lamppost”-type X-ray illuminator located near a standard accretion disk. Our results are better explained by assuming a hot accretion flow and a truncated disk.

  16. Nuclear activity and stellar population of a sample of interacting galaxies

    NASA Astrophysics Data System (ADS)

    Pastoriza, M. G.; Donzelli, C. J.; Bonatto, C.

    1999-07-01

    In this paper we investigate the nuclear activity and stellar population in a sample of 27 physical galaxy pairs. Equivalent widths of absorption features are used to characterise the nuclear stellar population according to templates: most galaxies of the sample have important flux contributions from stars younger than 10(8) years. According to classical diagnostic-diagrams the galaxies in our sample are either classified as H II regions or have emission line ratios near the transition zone between H II regions and LINERs. Based on the observed spectra, only 4 galaxies show LINER properties and 1 nucleus is a Seyfert 2. We found that the spectrum of a transition object (38% of the sample) can be described by a combination of an AGN with an H II region. As a result, 20 galaxies of the present sample may host a low-luminosity active nucleus. Based on observations made at CASLEO and CTIO. Complejo Astronómico El Leoncito (CASLEO) is operated under agreement between the Consejo Nacional de Investigaciones Cient\\'\\i ficas y Técnicas de la República Argentina and the National Universities of La Plata, Córdoba and San Juan.

  17. Mid-IR Properties of an Unbiased AGN Sample of the Local Universe. 1; Emission-Line Diagnostics

    NASA Technical Reports Server (NTRS)

    Weaver, K. A.; Melendez, M.; Muhotzky, R. F.; Kraemer, S.; Engle, K.; Malumuth. E.; Tueller, J.; Markwardt, C.; Berghea, C. T.; Dudik, R. P.; Winter, L. M.; Armus, L.

    2010-01-01

    \\Ve compare mid-IR emission-lines properties, from high-resolution Spitzer IRS spectra of a statistically-complete hard X-ray (14-195 keV) selected sample of nearby (z < 0.05) AGN detected by the Burst Alert Telescope (BAT) aboard Swift. The luminosity distribution for the mid-infrared emission-lines, [O IV] 25.89 microns, [Ne II] 12.81 microns, [Ne III] 15.56 microns and [Ne V] 14.32 microns, and hard X-ray continuum show no differences between Seyfert 1 and Seyfert 2 populations, although six newly discovered BAT AGNs are shown to be under-luminous in [O IV], most likely the result of dust extinction in the host galaxy. The overall tightness of the mid-infrared correlations and BAT luminosities suggests that the emission lines primarily arise in gas ionized by the AGN. We also compared the mid-IR emission-lines in the BAT AGNs with those from published studies of star-forming galaxies and LINERs. We found that the BAT AGN fall into a distinctive region when comparing the [Ne III]/[Ne II] and the [O IV]/[Ne III] quantities. From this we found that sources that have been previously classified in the mid-infrared/optical as AGN have smaller emission line ratios than those found for the BAT AGNs, suggesting that, in our X-ray selected sample, the AGN represents the main contribution to the observed line emission. Overall, we present a different set of emission line diagnostics to distinguish between AGN and star forming galaxies that can be used as a tool to find new AGN.

  18. X-ray Properties of an Unbiased Hard X-ray Detected Sample of AGN

    NASA Technical Reports Server (NTRS)

    Winter, Lisa M.; Mushotzky, Richard F.; Tueller, Jack; Markwardt, Craig

    2007-01-01

    The SWIFT gamma ray observatory's Burst Alert Telescope (BAT) has detected a sample of active galactic nuclei (AGN) based solely on their hard X-ray flux (14-195keV). In this paper, we present for the first time XMM-Newton X-ray spectra for 22 BAT AGXs with no previously analyzed X-ray spectra. If our sources are a representative sample of the BAT AGN, as we claim, our results present for the first time global X-ray properties of an unbiased towards absorption (n(sub H) < 3 x 10(exp 25)/sq cm), local (< z >= 0.03), AGN sample. We find 9/22 low absorption (n(sub H) < 10(exp 23)/sq cm), simple power law model sources, where 4 of these sources have a statistically significant soft component. Among these sources, we find the presence of a warm absorber statistically significant for only one Seyfert 1 source, contrasting with the ASCA results of Reynolds (1997) and George et al. (1998), who find signatures of warm absorption in half or more of their Seyfert 1 samples at similar redshifts. Additionally, the remaining sources (13122) have more complex spectra, well-fit by an absorbed power law at E > 2.0 keV. Five of the complex sources (NGC 612, ESO 362-G018, MRK 417, ESO 506-G027, and NGC 6860) are classified as Compton-thick candidates. Further, we find four more sources (SWIFT J0641.3+3257, SWIFT J0911.2+4533, SWIFT J1200.8+0650, and NGC 4992) with properties consistent with the hidden/buried AGN reported by Ueda et al. (2007). Finally, we include a comparison of the XMM EPIC spectra with available SWIFT X-ray Telescope (XRT) observations. From these comparisons, we find 6/16 sources with varying column densities, 6/16 sources with varying power law indices, and 13/16 sources with varying fluxes, over periods of hours to months. Flux and power law index are correlated for objects where both parameters vary.

  19. 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

  20. Precision Fe K-Alpha and Fe K-Beta Line Spectroscopy of the Seyfert 1.9 Galaxy NGC 2992 with Suzaku

    NASA Technical Reports Server (NTRS)

    Yaqoob, Tahir; Murphy, Kendrah D.; Griffiths, Richard E.; Haba, Yoshito; Inoue, Hajime; Itoh, Takeshi; Kelley, Richard; Kokubun, Motohide; Markowitz, Alex; Mushotzky, Richard; Okajima, Takashi; Ptak, Andrew; Reeves, James; Selemitos, Peter J.; Takahashi, Tadayuki; Terashima, Yuichi

    2006-01-01

    We present detailed time-averaged X-ray spectroscopy in the 0.5-10 keV band of the Seyfert 1.9 galaxy NGC 2992 with the Suzaku X-ray Imaging Spectrometers (XIS). The source had a factor approximately 3 higher 2-10 keV flux (approximately 1.2 x l0(exp -11) erg per square cm per s) than the historical minimum and a factor approximately 7 less than the historical maximum. The XIS spectrum of NGC 2992 can be described by several components. There is a primary continuum, modeled as a power-law with a photon index of Gamma = 1.57(sup +0.06) (sup -0.03) that is obscured by a Compton-thin absorber with a column density of 8.01(sup +0.6) (sup -0.5)x l0 (exp 21) per square cm. . There is another, weaker, unabsorbed power-law component (modeled with the same slope as the primary), that is likely to be due to the primary continuum being electron-scattered into our line-of-sight by a region extended on a scale of hundreds of parsecs. We measure the Thomson depth of the scattering zone to be Tau = 0.072 +/- 0.021. An optically-thin thermal continuum emission component, which probably originates in the same extended region, is included in the model and yields a temperature and luminosity of KT = 0.656(sup +0.088) (sup -0.0.61) keV and approximately 1.2 +/- 0.4 x l0 (exp 40) erg per s respectively. We detect an Fe K emission complex which we model with broad and narrow lines and we show that the intensities of the two components are decoupled at a confidence level > 3 sigma. The broad Fe K alpha line has an equivalent width of 118(sup +32) (sup -61) eV and could originate in an accretion disk (with inclination angle greater than approximately 30 deg) around the putative central black hole. The narrow Fe K alpha line has an equivalent width of 1632(sup +47) (sup -26) eV and is unresolved (FWHM < 4630 km per s) and likely originates in distant matter. The absolute flux in the narrow line implies that the column density out of the line-of-sight could be much higher than measured in

  1. A Mars Sample Return Sample Handling System

    NASA Technical Reports Server (NTRS)

    Wilson, David; Stroker, Carol

    2013-01-01

    We present a sample handling system, a subsystem of the proposed Dragon landed Mars Sample Return (MSR) mission [1], that can return to Earth orbit a significant mass of frozen Mars samples potentially consisting of: rock cores, subsurface drilled rock and ice cuttings, pebble sized rocks, and soil scoops. The sample collection, storage, retrieval and packaging assumptions and concepts in this study are applicable for the NASA's MPPG MSR mission architecture options [2]. Our study assumes a predecessor rover mission collects samples for return to Earth to address questions on: past life, climate change, water history, age dating, understanding Mars interior evolution [3], and, human safety and in-situ resource utilization. Hence the rover will have "integrated priorities for rock sampling" [3] that cover collection of subaqueous or hydrothermal sediments, low-temperature fluidaltered rocks, unaltered igneous rocks, regolith and atmosphere samples. Samples could include: drilled rock cores, alluvial and fluvial deposits, subsurface ice and soils, clays, sulfates, salts including perchlorates, aeolian deposits, and concretions. Thus samples will have a broad range of bulk densities, and require for Earth based analysis where practical: in-situ characterization, management of degradation such as perchlorate deliquescence and volatile release, and contamination management. We propose to adopt a sample container with a set of cups each with a sample from a specific location. We considered two sample cups sizes: (1) a small cup sized for samples matching those submitted to in-situ characterization instruments, and, (2) a larger cup for 100 mm rock cores [4] and pebble sized rocks, thus providing diverse samples and optimizing the MSR sample mass payload fraction for a given payload volume. We minimize sample degradation by keeping them frozen in the MSR payload sample canister using Peltier chip cooling. The cups are sealed by interference fitted heat activated memory

  2. A multiparametric analysis of the Einstein sample of early-type galaxies. 1: Luminosity and ISM parameters

    NASA Technical Reports Server (NTRS)

    Eskridge, Paul B.; Fabbiano, Giuseppina; Kim, Dong-Woo

    1995-01-01

    We have conducted bivariate and multivariate statistical analysis of data measuring the luminosity and interstellar medium of the Einstein sample of early-type galaxies (presented by Fabbiano, Kim, & Trinchieri 1992). We find a strong nonlinear correlation between L(sub B) and L(sub X), with a power-law slope of 1.8 +/- 0.1, steepening to 2.0 +/- if we do not consider the Local Group dwarf galaxies M32 and NGC 205. Considering only galaxies with log L(sub X) less than or equal to 40.5, we instead find a slope of 1.0 +/- 0.2 (with or without the Local Group dwarfs). Although E and S0 galaxies have consistent slopes for their L(sub B)-L(sub X) relationships, the mean values of the distribution functions of both L(sub X) and L(sub X)/L(sub B) for the S0 galaxies are lower than those for the E galaxies at the 2.8 sigma and 3.5 sigma levels, respectively. We find clear evidence for a correlation between L(sub X) and the X-ray color C(sub 21), defined by Kim, Fabbiano, & Trinchieri (1992b), which indicates that X-ray luminosity is correlated with the spectral shape below 1 keV in the sense that low-L(sub X) systems have relatively large contributions from a soft component compared with high-L(sub X) systems. We find evidence from our analysis of the 12 micron IRAS data for our sample that our S0 sample has excess 12 micron emission compared with the E sample, scaled by their optical luminosities. This may be due to emission from dust heated in star-forming regions in S0 disks. This interpretation is reinforced by the existence of a strong L(sub 12)-L(sub 100) correlation for our S0 sample that is not found for the E galaxies, and by an analysis of optical-IR colors. We find steep slopes for power-law relationships between radio luminosity and optical, X-ray, and far-IR (FIR) properties. This last point argues that the presence of an FIR-emitting interstellar medium (ISM) in early-type galaxies is coupled to their ability to generate nonthermal radio continuum, as

  3. Zooming into γ-ray loud galactic nuclei: broadband emission and structure dynamics of the blazar PKS 1502+106 and the narrow-line Seyfert 1 1H 0323+342

    NASA Astrophysics Data System (ADS)

    Karamanavis, Vasileios (Vassilis)

    2015-05-01

    Blazars are accretion-powered systems representing the most extreme flavor of active galactic nuclei (AGN). This thesis focuses on the study of blazar PKS 1502+106 during a prominent broadband outburst using ultra-high resolution imaging and a broadband single-dish study. The former is accomplished through very-long-baseline interferometry (VLBI) down to short millimeter (mm) wavelengths, while the latter uses densely-sampled radio light curves at a wide frequency range. The same combination allows the detailed study of the galaxy 1H 0323+342. This is a prominent member of the narrow-line Seyfert 1 (NLS1) class of AGN, recently discovered to emit gamma-rays. General aspects of AGN along with an introduction to their discovery, phenomenology, and their constituent parts are discussed in Chapter 1. Here, specific aspects of blazars and concepts used in later chapters are also introduced. Chapter 2 introduces the technique of VLBI from a theoretical standpoint, while in Chapter 3 the practical aspects of VLBI calibration and imaging at mm wavelengths are discussed. The phenomenology and physical characteristics of PKS 1502+106 through a cm- to mm-VLBI study are presented in Chapter 4. The data set features Global Millimeter VLBI Array (GMVA) observations at 7 mm (43 GHz) and 3 mm (86 GHz) along with complementary observations at 2 cm (15 GHz) from the MOJAVE program. We also combine the analysis with F-GAMMA program data at frequencies matching the VLBI monitoring and with the Fermi/LAT gamma-ray light curve. From the rich data set we deduce its kinematical and spectral characteristics which allow the inference of physical parameters of the ultra-relativistic jet of PKS 1502+106. For the jet features identified across observing frequencies we deduce Doppler factors in the range ~10-50 at different positions within the flow. Magnetic field strengths and brightness temperatures along the jet are also deduced. The position-dependent differences in viewing angle and

  4. THE X-RAY VARIABILITY OF A LARGE, SERENDIPITOUS SAMPLE OF SPECTROSCOPIC QUASARS

    SciTech Connect

    Gibson, Robert R.; Brandt, W. N.

    2012-02-10

    We analyze the X-ray variability of 264 Sloan Digital Sky Survey spectroscopic quasars using the Chandra public archive. This data set consists of quasars with spectroscopic redshifts out to z Almost-Equal-To 5 and covers rest-frame timescales up to {Delta}t{sub sys} Almost-Equal-To 2000 days, with three or more X-ray observations available for 82 quasars. It therefore samples longer timescales and higher luminosities than previous large-scale analyses of active galactic nucleus (AGN) variability. We find significant ({approx}>3{sigma}) variation in Almost-Equal-To 30% of the quasars overall; the fraction of sources with detected variability increases strongly with the number of available source counts up to Almost-Equal-To 70% for sources with {>=}1000 counts per epoch. Assuming that the distribution of fractional variation is Gaussian, its standard deviation is Almost-Equal-To 16% on {approx}>1 week timescales, which is not enough to explain the observed scatter in quasar X-ray-to-optical flux ratios as being due to variability alone. We find no evidence in our sample that quasars are more variable at higher redshifts (z > 2), as has been suggested in previous studies. Quasar X-ray spectra vary similarly to some local Seyfert AGNs in that they steepen as they brighten, with evidence for a constant, hard spectral component that is more prominent in fainter stages. We identify one highly variable Narrow Line Seyfert 1-type spectroscopic quasar in the Chandra Deep Field-North. We constrain the rate of kilosecond-timescale flares in the quasar population using Almost-Equal-To 8 months of total exposure and also constrain the distribution of variation amplitudes between exposures; extreme changes (>100%) are quite rare, while variation at the 25% level occurs in <25% of observations. [O III] {lambda}5007 A emission may be stronger in sources with lower levels of X-ray variability; if confirmed, this would represent an additional link between small-scale (corona) and

  5. Selecting a Sample

    ERIC Educational Resources Information Center

    Ritter, Lois A., Ed.; Sue, Valerie M., Ed.

    2007-01-01

    This chapter provides an overview of sampling methods that are appropriate for conducting online surveys. The authors review some of the basic concepts relevant to online survey sampling, present some probability and nonprobability techniques for selecting a sample, and briefly discuss sample size determination and nonresponse bias. Although some…

  6. Fluid sampling tool

    DOEpatents

    Garcia, Anthony R.; Johnston, Roger G.; Martinez, Ronald K.

    2000-01-01

    A fluid-sampling tool for obtaining a fluid sample from a container. When used in combination with a rotatable drill, the tool bores a hole into a container wall, withdraws a fluid sample from the container, and seals the borehole. The tool collects fluid sample without exposing the operator or the environment to the fluid or to wall shavings from the container.

  7. Digital adaptive sampling.

    NASA Technical Reports Server (NTRS)

    Breazeale, G. J.; Jones, L. E.

    1971-01-01

    Discussion of digital adaptive sampling, which is consistently better than fixed sampling in noise-free cases. Adaptive sampling is shown to be feasible and, it is considered, should be studied further. It should be noted that adaptive sampling is a class of variable rate sampling in which the variability depends on system signals. Digital rather than analog laws should be studied, because cases can arise in which the analog signals are not even available. An extremely important problem is implementation.

  8. Apollo 14 rock samples

    NASA Technical Reports Server (NTRS)

    Carlson, I. C.

    1978-01-01

    Petrographic descriptions of all Apollo 14 samples larger than 1 cm in any dimension are presented. The sample description format consists of: (1) an introductory section which includes information on lunar sample location, orientation, and return containers, (2) a section on physical characteristics, which contains the sample mass, dimensions, and a brief description; (3) surface features, including zap pits, cavities, and fractures as seen in binocular view; (4) petrographic description, consisting of a binocular description and, if possible, a thin section description; and (5) a discussion of literature relevant to sample petrology is included for samples which have previously been examined by the scientific community.

  9. Rain sampling device

    DOEpatents

    Nelson, Danny A.; Tomich, Stanley D.; Glover, Donald W.; Allen, Errol V.; Hales, Jeremy M.; Dana, Marshall T.

    1991-01-01

    The present invention constitutes a rain sampling device adapted for independent operation at locations remote from the user which allows rainfall to be sampled in accordance with any schedule desired by the user. The rain sampling device includes a mechanism for directing wet precipitation into a chamber, a chamber for temporarily holding the precipitation during the process of collection, a valve mechanism for controllably releasing samples of said precipitation from said chamber, a means for distributing the samples released from the holding chamber into vessels adapted for permanently retaining these samples, and an electrical mechanism for regulating the operation of the device.

  10. Stardust Sample: Investigator's Guidebook

    NASA Technical Reports Server (NTRS)

    Allen, Carl

    2006-01-01

    In January 2006, the Stardust spacecraft returned the first in situ collection of samples from a comet, and the first samples of contemporary interstellar dust. Stardust is the first US sample return mission from a planetary body since Apollo, and the first ever from beyond the moon. This handbook is a basic reference source for allocation procedures and policies for Stardust samples. These samples consist of particles and particle residues in aerogel collectors, in aluminum foil, and in spacecraft components. Contamination control samples and unflown collection media are also available for allocation.

  11. Rain sampling device

    DOEpatents

    Nelson, D.A.; Tomich, S.D.; Glover, D.W.; Allen, E.V.; Hales, J.M.; Dana, M.T.

    1991-05-14

    The present invention constitutes a rain sampling device adapted for independent operation at locations remote from the user which allows rainfall to be sampled in accordance with any schedule desired by the user. The rain sampling device includes a mechanism for directing wet precipitation into a chamber, a chamber for temporarily holding the precipitation during the process of collection, a valve mechanism for controllably releasing samples of the precipitation from the chamber, a means for distributing the samples released from the holding chamber into vessels adapted for permanently retaining these samples, and an electrical mechanism for regulating the operation of the device. 11 figures.

  12. A spectral atlas of the nu(sub 12) fundamental of (13)C(12)CH6 in the 12 micron region

    NASA Technical Reports Server (NTRS)

    Weber, Mark; Reuter, Dennis C.; Sirota, J. Marcos; Blass, William E.; Hillman, John J.

    1994-01-01

    The recent discovery of the minor isotopomer of ethane, (13)C(12)CH6, in the planetary atmospheres of Jupiter and Neptune, added ethane to the molecules which can be used to determine isotopic (12)C(12)C ratios for the jovian planets. The increased spectral resolution and coverage of the IR and far-IR instruments to be carried on the Cassini mission to Saturn and Titan may enable the detection of the minor isotopomer. Accurate frequency and cross-section measurements of the nu(sub 12) fundamental under controlled laboratory condition are important to interpret current and future planetary spectra. High resolution spectra of the minor isotopomer (13)C(12)CH6 have been recorded in the 12.2 micron region using the Kitt Peak Fourier Transform (FTS) and the Goddard Tunable Diode Laser spectrometer (TDL). In a global fit to 19 molecular constants in a symmetric top Hamiltonian, transition frequencies of the nu(sub 12) fundamental ranging up to J=35 and K=20 have been determined with a standard deviation of less than 0.0005 cm(exp -1). From selected line intensity measurements, a vibrational dipole moment for the nu(sub 12) fundamental has been derived. Observed and calculated spectra covering the region from 740 cm(exp -1) and to 910 cm(exp -1) are presented. A compilation of transition frequencies, line intensities, and lower state energies are included for general use in the astronomical community.

  13. Superposition Enhanced Nested Sampling

    NASA Astrophysics Data System (ADS)

    Martiniani, Stefano; Stevenson, Jacob D.; Wales, David J.; Frenkel, Daan

    2014-07-01

    The theoretical analysis of many problems in physics, astronomy, and applied mathematics requires an efficient numerical exploration of multimodal parameter spaces that exhibit broken ergodicity. Monte Carlo methods are widely used to deal with these classes of problems, but such simulations suffer from a ubiquitous sampling problem: The probability of sampling a particular state is proportional to its entropic weight. Devising an algorithm capable of sampling efficiently the full phase space is a long-standing problem. Here, we report a new hybrid method for the exploration of multimodal parameter spaces exhibiting broken ergodicity. Superposition enhanced nested sampling combines the strengths of global optimization with the unbiased or athermal sampling of nested sampling, greatly enhancing its efficiency with no additional parameters. We report extensive tests of this new approach for atomic clusters that are known to have energy landscapes for which conventional sampling schemes suffer from broken ergodicity. We also introduce a novel parallelization algorithm for nested sampling.

  14. GROUND WATER SAMPLING ISSUES

    EPA Science Inventory

    Obtaining representative ground water samples is important for site assessment and
    remedial performance monitoring objectives. Issues which must be considered prior to initiating a ground-water monitoring program include defining monitoring goals and objectives, sampling point...

  15. The broad-band X-ray spectrum of a QSO sample

    NASA Technical Reports Server (NTRS)

    Marshall, F. E.; Worrall, D. M.

    1984-01-01

    A sample of 25 QSOs is used to investigate the average spectrum between the soft X-ray energy band of the Einstein Observatory Image Proportional Counter, and the higher energy band of the HEAO 1 A-2 experiment. Assuming a power-law spectrum, a 90 percent confidence range is found for alpha(F(v) approximately v to the -alpha of 0.83 (+0.32, -0.22) for N(H) lower than 3 x 10 to the 20th atoms/sq cm. Higher column densities for QSOs are not anticipated, but if N(H) were about 10 to the 22nd atoms/sq cm, then alpha would be greater then 0.97. The present spectrum is similar to those exhibited by Seyfert galaxies and narrow emission line galaxies above 2 keV. The spectrum is soft enough that, if these objects are typical of the higher redshift, more radio-quiet QSOs, then QSOs can be excluded as being the dominant origin of the diffuse X-ray background.

  16. Improved Sampling Method Reduces Isokinetic Sampling Errors.

    ERIC Educational Resources Information Center

    Karels, Gale G.

    The particulate sampling system currently in use by the Bay Area Air Pollution Control District, San Francisco, California is described in this presentation for the 12th Conference on Methods in Air Pollution and Industrial Hygiene Studies, University of Southern California, April, 1971. The method represents a practical, inexpensive tool that can…

  17. Parallelized nested sampling

    NASA Astrophysics Data System (ADS)

    Henderson, R. Wesley; Goggans, Paul M.

    2014-12-01

    One of the important advantages of nested sampling as an MCMC technique is its ability to draw representative samples from multimodal distributions and distributions with other degeneracies. This coverage is accomplished by maintaining a number of so-called live samples within a likelihood constraint. In usual practice, at each step, only the sample with the least likelihood is discarded from this set of live samples and replaced. In [1], Skilling shows that for a given number of live samples, discarding only one sample yields the highest precision in estimation of the log-evidence. However, if we increase the number of live samples, more samples can be discarded at once while still maintaining the same precision. For computer code running only serially, this modification would considerably increase the wall clock time necessary to reach convergence. However, if we use a computer with parallel processing capabilities, and we write our code to take advantage of this parallelism to replace multiple samples concurrently, the performance penalty can be eliminated entirely and possibly reversed. In this case, we must use the more general equation in [1] for computing the expectation of the shrinkage distribution: E [- log t]= (N r-r+1)-1+(Nr-r+2)-1+⋯+Nr-1, for shrinkage t with Nr live samples and r samples discarded at each iteration. The equation for the variance Var (- log t)= (N r-r+1)-2+(Nr-r+2)-2+⋯+Nr-2 is used to find the appropriate number of live samples Nr to use with r > 1 to match the variance achieved with N1 live samples and r = 1. In this paper, we show that by replacing multiple discarded samples in parallel, we are able to achieve a more thorough sampling of the constrained prior distribution, reduce runtime, and increase precision.

  18. Developing Water Sampling Standards

    ERIC Educational Resources Information Center

    Environmental Science and Technology, 1974

    1974-01-01

    Participants in the D-19 symposium on aquatic sampling and measurement for water pollution assessment were informed that determining the extent of waste water stream pollution is not a cut and dry procedure. Topics discussed include field sampling, representative sampling from storm sewers, suggested sampler features and application of improved…

  19. SAMPLING OF CONTAMINATED SITES

    EPA Science Inventory

    A critical aspect of characterization of the amount and species of contamination of a hazardous waste site is the sampling plan developed for that site. f the sampling plan is not thoroughly conceptualized before sampling takes place, then certain critical aspects of the limits o...

  20. ORGANIC SPECIATION SAMPLING ARTIFACTS

    EPA Science Inventory

    Sampling artifacts for molecular markers from organic speciation of particulate matter were investigated by analyzing forty-one samples collected in Philadelphia as a part of the Northeast Oxidant and Particulate Study (NEOPS). Samples were collected using a high volume sampler ...

  1. Decision by Sampling

    ERIC Educational Resources Information Center

    Stewart, Neil; Chater, Nick; Brown, Gordon D. A.

    2006-01-01

    We present a theory of decision by sampling (DbS) in which, in contrast with traditional models, there are no underlying psychoeconomic scales. Instead, we assume that an attribute's subjective value is constructed from a series of binary, ordinal comparisons to a sample of attribute values drawn from memory and is its rank within the sample. We…

  2. Aerosol sampling system

    DOEpatents

    Masquelier, Donald A.

    2004-02-10

    A system for sampling air and collecting particulate of a predetermined particle size range. A low pass section has an opening of a preselected size for gathering the air but excluding particles larger than the sample particles. An impactor section is connected to the low pass section and separates the air flow into a bypass air flow that does not contain the sample particles and a product air flow that does contain the sample particles. A wetted-wall cyclone collector, connected to the impactor section, receives the product air flow and traps the sample particles in a liquid.

  3. Rockballer Sample Acquisition Tool

    NASA Technical Reports Server (NTRS)

    Giersch, Louis R.; Cook, Brant T.

    2013-01-01

    It would be desirable to acquire rock and/or ice samples that extend below the surface of the parent rock or ice in extraterrestrial environments such as the Moon, Mars, comets, and asteroids. Such samples would allow measurements to be made further back into the geologic history of the rock, providing critical insight into the history of the local environment and the solar system. Such samples could also be necessary for sample return mission architectures that would acquire samples from extraterrestrial environments for return to Earth for more detailed scientific investigation.

  4. Sample Caching Subsystem

    NASA Technical Reports Server (NTRS)

    Backes, Paul G.; Collins, Curtis L.

    2007-01-01

    A paper describes the Sample Caching Subsystem (SCS), a method for storing planetary core and soil samples in a container that seals the samples away from the environment to protect the integrity of the samples and any organics they might contain. This process places samples in individual sleeves that are sealed within a container for use by either the current mission or by following missions. A sample container is stored with its sleeves partially inserted. When a sample is ready to be contained, a transfer arm rotates over and grasps a sleeve, pulls it out of the container from below, rotates over and inserts the sleeve into a funnel where it is passively locked into place and then released from the arm. An external sampling tool deposits the sample into the sleeve, which is aligned with the tool via passive compliance of the funnel. After the sampling tool leaves the funnel, the arm retrieves the sleeve and inserts it all the way into the sample container. This action engages the seal. Full containers can be left behind for pick-up by subsequent science missions, and container dimensions are compatible for placement in a Mars Ascent Vehicle for later return to Earth.

  5. The Lunar Sample Compendium

    NASA Technical Reports Server (NTRS)

    Meyer, Charles

    2009-01-01

    The Lunar Sample Compendium is a succinct summary of the data obtained from 40 years of study of Apollo and Luna samples of the Moon. Basic petrographic, chemical and age information is compiled, sample-by-sample, in the form of an advanced catalog in order to provide a basic description of each sample. The LSC can be found online using Google. The initial allocation of lunar samples was done sparingly, because it was realized that scientific techniques would improve over the years and new questions would be formulated. The LSC is important because it enables scientists to select samples within the context of the work that has already been done and facilitates better review of proposed allocations. It also provides back up material for public displays, captures information found only in abstracts, grey literature and curatorial databases and serves as a ready access to the now-vast scientific literature.

  6. Phylogenetic effective sample size.

    PubMed

    Bartoszek, Krzysztof

    2016-10-21

    In this paper I address the question-how large is a phylogenetic sample? I propose a definition of a phylogenetic effective sample size for Brownian motion and Ornstein-Uhlenbeck processes-the regression effective sample size. I discuss how mutual information can be used to define an effective sample size in the non-normal process case and compare these two definitions to an already present concept of effective sample size (the mean effective sample size). Through a simulation study I find that the AICc is robust if one corrects for the number of species or effective number of species. Lastly I discuss how the concept of the phylogenetic effective sample size can be useful for biodiversity quantification, identification of interesting clades and deciding on the importance of phylogenetic correlations. PMID:27343033

  7. Sample Proficiency Test exercise

    SciTech Connect

    Alcaraz, A; Gregg, H; Koester, C

    2006-02-05

    The current format of the OPCW proficiency tests has multiple sets of 2 samples sent to an analysis laboratory. In each sample set, one is identified as a sample, the other as a blank. This method of conducting proficiency tests differs from how an OPCW designated laboratory would receive authentic samples (a set of three containers, each not identified, consisting of the authentic sample, a control sample, and a blank sample). This exercise was designed to test the reporting if the proficiency tests were to be conducted. As such, this is not an official OPCW proficiency test, and the attached report is one method by which LLNL might report their analyses under a more realistic testing scheme. Therefore, the title on the report ''Report of the Umpteenth Official OPCW Proficiency Test'' is meaningless, and provides a bit of whimsy for the analyses and readers of the report.

  8. Curation of Frozen Samples

    NASA Technical Reports Server (NTRS)

    Fletcher, L. A.; Allen, C. C.; Bastien, R.

    2008-01-01

    NASA's Johnson Space Center (JSC) and the Astromaterials Curator are charged by NPD 7100.10D with the curation of all of NASA s extraterrestrial samples, including those from future missions. This responsibility includes the development of new sample handling and preparation techniques; therefore, the Astromaterials Curator must begin developing procedures to preserve, prepare and ship samples at sub-freezing temperatures in order to enable future sample return missions. Such missions might include the return of future frozen samples from permanently-shadowed lunar craters, the nuclei of comets, the surface of Mars, etc. We are demonstrating the ability to curate samples under cold conditions by designing, installing and testing a cold curation glovebox. This glovebox will allow us to store, document, manipulate and subdivide frozen samples while quantifying and minimizing contamination throughout the curation process.

  9. Lunar Sample Compendium

    NASA Technical Reports Server (NTRS)

    Meyer, C.

    2009-01-01

    The Lunar Sample Compendium is a succinct summary of what has been learned from the study of Apollo and Luna samples of the Moon. Basic information is compiled, sample-by-sample, in the form of an advanced catalog in order to provide a basic description of each sample. Information presented is carefully attributed to the original source publication, thus the Compendium also serves as a ready access to the now vast scientific literature pertaining to lunar smples. The Lunar Sample Compendium is a work in progress (and may always be). Future plans include: adding sections on additional samples, adding new thin section photomicrographs, replacing the faded photographs with newly digitized photos from the original negatives, attempting to correct the age data using modern decay constants, adding references to each section, and adding an internal search engine.

  10. Urine sample collection protocols for bioassay samples

    SciTech Connect

    MacLellan, J.A.; McFadden, K.M.

    1992-11-01

    In vitro radiobioassay analyses are used to measure the amount of radioactive material excreted by personnel exposed to the potential intake of radioactive material. The analytical results are then used with various metabolic models to estimate the amount of radioactive material in the subject's body and the original intake of radioactive material. Proper application of these metabolic models requires knowledge of the excretion period. It is normal practice to design the bioassay program based on a 24-hour excretion sample. The Hanford bioassay program simulates a total 24-hour urine excretion sample with urine collection periods lasting from one-half hour before retiring to one-half hour after rising on two consecutive days. Urine passed during the specified periods is collected in three 1-L bottles. Because the daily excretion volume given in Publication 23 of the International Commission on Radiological Protection (ICRP 1975, p. 354) for Reference Man is 1.4 L, it was proposed to use only two 1-L bottles as a cost-saving measure. This raised the broader question of what should be the design capacity of a 24-hour urine sample kit.

  11. Urine sample collection protocols for bioassay samples

    SciTech Connect

    MacLellan, J.A.; McFadden, K.M.

    1992-11-01

    In vitro radiobioassay analyses are used to measure the amount of radioactive material excreted by personnel exposed to the potential intake of radioactive material. The analytical results are then used with various metabolic models to estimate the amount of radioactive material in the subject`s body and the original intake of radioactive material. Proper application of these metabolic models requires knowledge of the excretion period. It is normal practice to design the bioassay program based on a 24-hour excretion sample. The Hanford bioassay program simulates a total 24-hour urine excretion sample with urine collection periods lasting from one-half hour before retiring to one-half hour after rising on two consecutive days. Urine passed during the specified periods is collected in three 1-L bottles. Because the daily excretion volume given in Publication 23 of the International Commission on Radiological Protection (ICRP 1975, p. 354) for Reference Man is 1.4 L, it was proposed to use only two 1-L bottles as a cost-saving measure. This raised the broader question of what should be the design capacity of a 24-hour urine sample kit.

  12. Sampling diffusive transition paths

    SciTech Connect

    F. Miller III, Thomas; Predescu, Cristian

    2006-10-12

    We address the problem of sampling double-ended diffusive paths. The ensemble of paths is expressed using a symmetric version of the Onsager-Machlup formula, which only requires evaluation of the force field and which, upon direct time discretization, gives rise to a symmetric integrator that is accurate to second order. Efficiently sampling this ensemble requires avoiding the well-known stiffness problem associated with sampling infinitesimal Brownian increments of the path, as well as a different type of stiffness associated with sampling the coarse features of long paths. The fine-features sampling stiffness is eliminated with the use of the fast sampling algorithm (FSA), and the coarse-feature sampling stiffness is avoided by introducing the sliding and sampling (S&S) algorithm. A key feature of the S&S algorithm is that it enables massively parallel computers to sample diffusive trajectories that are long in time. We use the algorithm to sample the transition path ensemble for the structural interconversion of the 38-atom Lennard-Jones cluster at low temperature.

  13. Sampling in Qualitative Research

    PubMed Central

    LUBORSKY, MARK R.; RUBINSTEIN, ROBERT L.

    2011-01-01

    In gerontology the most recognized and elaborate discourse about sampling is generally thought to be in quantitative research associated with survey research and medical research. But sampling has long been a central concern in the social and humanistic inquiry, albeit in a different guise suited to the different goals. There is a need for more explicit discussion of qualitative sampling issues. This article will outline the guiding principles and rationales, features, and practices of sampling in qualitative research. It then describes common questions about sampling in qualitative research. In conclusion it proposes the concept of qualitative clarity as a set of principles (analogous to statistical power) to guide assessments of qualitative sampling in a particular study or proposal. PMID:22058580

  14. Sampling functions for geophysics

    NASA Technical Reports Server (NTRS)

    Giacaglia, G. E. O.; Lunquist, C. A.

    1972-01-01

    A set of spherical sampling functions is defined such that they are related to spherical-harmonic functions in the same way that the sampling functions of information theory are related to sine and cosine functions. An orderly distribution of (N + 1) squared sampling points on a sphere is given, for which the (N + 1) squared spherical sampling functions span the same linear manifold as do the spherical-harmonic functions through degree N. The transformations between the spherical sampling functions and the spherical-harmonic functions are given by recurrence relations. The spherical sampling functions of two arguments are extended to three arguments and to nonspherical reference surfaces. Typical applications of this formalism to geophysical topics are sketched.

  15. Sample positioning in microgravity

    NASA Technical Reports Server (NTRS)

    Sridharan, Govind (Inventor)

    1991-01-01

    Repulsion forces arising from laser beams are provided to produce mild positioning forces on a sample in microgravity vacuum environments. The system of the preferred embodiment positions samples using a plurality of pulsed lasers providing opposing repulsion forces. The lasers are positioned around the periphery of a confinement area and expanded to create a confinement zone. The grouped laser configuration, in coordination with position sensing devices, creates a feedback servo whereby stable position control of a sample within microgravity environment can be achieved.

  16. Sample positioning in microgravity

    NASA Technical Reports Server (NTRS)

    Sridharan, Govind (Inventor)

    1993-01-01

    Repulsion forces arising from laser beams are provided to produce mild positioning forces on a sample in microgravity vacuum environments. The system of the preferred embodiment positions samples using a plurality of pulsed lasers providing opposing repulsion forces. The lasers are positioned around the periphery of a confinement area and expanded to create a confinement zone. The grouped laser configuration, in coordination with position sensing devices, creates a feedback servo whereby stable position control of a sample within microgravity environment can be achieved.

  17. Statistical distribution sampling

    NASA Technical Reports Server (NTRS)

    Johnson, E. S.

    1975-01-01

    Determining the distribution of statistics by sampling was investigated. Characteristic functions, the quadratic regression problem, and the differential equations for the characteristic functions are analyzed.

  18. Nested sampling with demons

    NASA Astrophysics Data System (ADS)

    Habeck, Michael

    2015-01-01

    This article looks at Skilling's nested sampling from a physical perspective and interprets it as a microcanonical demon algorithm. Using key quantities of statistical physics we investigate the performance of nested sampling on complex systems such as Ising, Potts and protein models. We show that releasing multiple demons helps to smooth the truncated prior and eases sampling from it because the demons keep the particle off the constraint boundary. For continuous systems it is straightforward to extend this approach and formulate a phase space version of nested sampling that benefits from correlated explorations guided by Hamiltonian dynamics.

  19. Urine sample (image)

    MedlinePlus

    ... catch" urine sample is performed by collecting the sample of urine in midstream. Men or boys should wipe clean the head of the penis. Women or girls need to wash the area between the lips of the vagina with soapy water and rinse well. A small amount of urine ...

  20. National Sample Assessment Protocols

    ERIC Educational Resources Information Center

    Ministerial Council on Education, Employment, Training and Youth Affairs (NJ1), 2012

    2012-01-01

    These protocols represent a working guide for planning and implementing national sample assessments in connection with the national Key Performance Measures (KPMs). The protocols are intended for agencies involved in planning or conducting national sample assessments and personnel responsible for administering associated tenders or contracts,…

  1. Adaptive Sampling Proxy Application

    2012-10-22

    ASPA is an implementation of an adaptive sampling algorithm [1-3], which is used to reduce the computational expense of computer simulations that couple disparate physical scales. The purpose of ASPA is to encapsulate the algorithms required for adaptive sampling independently from any specific application, so that alternative algorithms and programming models for exascale computers can be investigated more easily.

  2. Creating Sample Plans

    1999-03-24

    The program has been designed to increase the accuracy and reduce the preparation time for completing sampling plans. It consists of our files 1. Analyte/Combination (AnalCombo) A list of analytes and combinations of analytes that can be requested of the onsite and offsite labs. Whenever a specific combination of analytes or suite names appear on the same line as the code number, this indicates that one sample can be placed in one bottle to bemore » analyzed for these paremeters. A code number is assigned for each analyte and combination of analytes. 2. Sampling Plans Database (SPDb) A database that contains all of the analytes and combinations of analytes along with the basic information required for preparing a sample plan. That basic information includes the following fields; matrix, hold time, preservation, sample volume, container size, if the bottle caps are taped, acceptable choices. 3. Sampling plans create (SPcreate) a file that will lookup information from the Sampling Plans Database and the Job Log File (JLF98) A major database used by Sample Managemnet Services for recording more than 100 fields of information.« less

  3. Sampling system and method

    DOEpatents

    Decker, David L.; Lyles, Brad F.; Purcell, Richard G.; Hershey, Ronald Lee

    2013-04-16

    The present disclosure provides an apparatus and method for coupling conduit segments together. A first pump obtains a sample and transmits it through a first conduit to a reservoir accessible by a second pump. The second pump further conducts the sample from the reservoir through a second conduit.

  4. Biological sample collector

    DOEpatents

    Murphy, Gloria A.

    2010-09-07

    A biological sample collector is adapted to a collect several biological samples in a plurality of filter wells. A biological sample collector may comprise a manifold plate for mounting a filter plate thereon, the filter plate having a plurality of filter wells therein; a hollow slider for engaging and positioning a tube that slides therethrough; and a slide case within which the hollow slider travels to allow the tube to be aligned with a selected filter well of the plurality of filter wells, wherein when the tube is aligned with the selected filter well, the tube is pushed through the hollow slider and into the selected filter well to sealingly engage the selected filter well and to allow the tube to deposit a biological sample onto a filter in the bottom of the selected filter well. The biological sample collector may be portable.

  5. Rapid Active Sampling Package

    NASA Technical Reports Server (NTRS)

    Peters, Gregory

    2010-01-01

    A field-deployable, battery-powered Rapid Active Sampling Package (RASP), originally designed for sampling strong materials during lunar and planetary missions, shows strong utility for terrestrial geological use. The technology is proving to be simple and effective for sampling and processing materials of strength. Although this originally was intended for planetary and lunar applications, the RASP is very useful as a powered hand tool for geologists and the mining industry to quickly sample and process rocks in the field on Earth. The RASP allows geologists to surgically acquire samples of rock for later laboratory analysis. This tool, roughly the size of a wrench, allows the user to cut away swaths of weathering rinds, revealing pristine rock surfaces for observation and subsequent sampling with the same tool. RASPing deeper (.3.5 cm) exposes single rock strata in-situ. Where a geologist fs hammer can only expose unweathered layers of rock, the RASP can do the same, and then has the added ability to capture and process samples into powder with particle sizes less than 150 microns, making it easier for XRD/XRF (x-ray diffraction/x-ray fluorescence). The tool uses a rotating rasp bit (or two counter-rotating bits) that resides inside or above the catch container. The container has an open slot to allow the bit to extend outside the container and to allow cuttings to enter and be caught. When the slot and rasp bit are in contact with a substrate, the bit is plunged into it in a matter of seconds to reach pristine rock. A user in the field may sample a rock multiple times at multiple depths in minutes, instead of having to cut out huge, heavy rock samples for transport back to a lab for analysis. Because of the speed and accuracy of the RASP, hundreds of samples can be taken in one day. RASP-acquired samples are small and easily carried. A user can characterize more area in less time than by using conventional methods. The field-deployable RASP used a Ni

  6. Waste classification sampling plan

    SciTech Connect

    Landsman, S.D.

    1998-05-27

    The purpose of this sampling is to explain the method used to collect and analyze data necessary to verify and/or determine the radionuclide content of the B-Cell decontamination and decommissioning waste stream so that the correct waste classification for the waste stream can be made, and to collect samples for studies of decontamination methods that could be used to remove fixed contamination present on the waste. The scope of this plan is to establish the technical basis for collecting samples and compiling quantitative data on the radioactive constituents present in waste generated during deactivation activities in B-Cell. Sampling and radioisotopic analysis will be performed on the fixed layers of contamination present on structural material and internal surfaces of process piping and tanks. In addition, dose rate measurements on existing waste material will be performed to determine the fraction of dose rate attributable to both removable and fixed contamination. Samples will also be collected to support studies of decontamination methods that are effective in removing the fixed contamination present on the waste. Sampling performed under this plan will meet criteria established in BNF-2596, Data Quality Objectives for the B-Cell Waste Stream Classification Sampling, J. M. Barnett, May 1998.

  7. Sampling video compression system

    NASA Technical Reports Server (NTRS)

    Matsumoto, Y.; Lum, H. (Inventor)

    1977-01-01

    A system for transmitting video signal of compressed bandwidth is described. The transmitting station is provided with circuitry for dividing a picture to be transmitted into a plurality of blocks containing a checkerboard pattern of picture elements. Video signals along corresponding diagonal rows of picture elements in the respective blocks are regularly sampled. A transmitter responsive to the output of the sampling circuitry is included for transmitting the sampled video signals of one frame at a reduced bandwidth over a communication channel. The receiving station is provided with a frame memory for temporarily storing transmitted video signals of one frame at the original high bandwidth frequency.

  8. Sample positioning apparatus

    DOEpatents

    Bell, Thomas H.; Johnson, Jr., Charles H.; Lane, Robert L.; Martin, Bradley E.; Tyree, William H.

    1976-01-06

    Apparatus for use in alpha particle counting with such as photomultiplier tubes, comprising a platform and linkage mechanism whereby samples are moved in linear manner toward and away from ends of the photomultiplier tubes.

  9. Lunar sample contracts

    NASA Technical Reports Server (NTRS)

    Walker, R. M.

    1974-01-01

    The major scientific accomplishments through 1971 are reported for the particle track studies of lunar samples. Results are discussed of nuclear track measurements by optical and electron microscopy, thermoluminescence, X-ray diffraction, and differential thermal analysis.

  10. [Foetal sampling techniques].

    PubMed

    Levy, R; Arfi, J-S; Daffos, F

    2003-06-01

    This article describes the current techniques of foetal sampling. All of them are actually ultrasound guided, and therefore generally very safe. Nevertheless, an elaborate learning process remains indispensable, in addition to a particular attention to the quality of the physician-patient dialogue. The choice of a technique depends on the indication and on the term of the pregnancy. The most frequently used technique is amniocentesis which presents a low risk of foetal loss, estimated between 0.2 and 0.5 percent. The interest of chorionic villus sampling is the possibility to obtain results at an earlier stage of pregnancy, with a lower risk taking when compared to early amniocentesis. We prefer the transabdominal chorionic villus sampling to the transvaginal. Foetal blood sampling is still required in some cases, but the risk of complications is higher--around 1 percent. PMID:12865196

  11. Water Sample Concentrator

    SciTech Connect

    Idaho National Laboratory

    2009-07-21

    Automated portable device that concentrates and packages a sample of suspected contaminated water for safe, efficient transport to a qualified analytical laboratory. This technology will help safeguard against pathogen contamination or chemical and biolog

  12. Sealed container sampling device

    NASA Technical Reports Server (NTRS)

    Hennigan, T. J.

    1969-01-01

    Sampling device, by means of a tapered needle, pierces a sealed container while maintaining the seal and either evacuates or pressurizes the container. This device has many applications in the chemical, preservative and battery-manufacturing industries.

  13. Water Sample Concentrator

    ScienceCinema

    Idaho National Laboratory

    2016-07-12

    Automated portable device that concentrates and packages a sample of suspected contaminated water for safe, efficient transport to a qualified analytical laboratory. This technology will help safeguard against pathogen contamination or chemical and biolog

  14. Dissolution actuated sample container

    DOEpatents

    Nance, Thomas A.; McCoy, Frank T.

    2013-03-26

    A sample collection vial and process of using a vial is provided. The sample collection vial has an opening secured by a dissolvable plug. When dissolved, liquids may enter into the interior of the collection vial passing along one or more edges of a dissolvable blocking member. As the blocking member is dissolved, a spring actuated closure is directed towards the opening of the vial which, when engaged, secures the vial contents against loss or contamination.

  15. SAMPLING AND ANALYSIS PROTOCOLS

    SciTech Connect

    Jannik, T; P Fledderman, P

    2007-02-09

    Radiological sampling and analyses are performed to collect data for a variety of specific reasons covering a wide range of projects. These activities include: Effluent monitoring; Environmental surveillance; Emergency response; Routine ambient monitoring; Background assessments; Nuclear license termination; Remediation; Deactivation and decommissioning (D&D); and Waste management. In this chapter, effluent monitoring and environmental surveillance programs at nuclear operating facilities and radiological sampling and analysis plans for remediation and D&D activities will be discussed.

  16. TANK 5 SAMPLING

    SciTech Connect

    Vrettos, N; William Cheng, W; Thomas Nance, T

    2007-11-26

    Tank 5 at the Savannah River Site has been used to store high level waste and is currently undergoing waste removal processes in preparation for tank closure. Samples were taken from two locations to determine the contents in support of Documented Safety Analysis (DSA) development for chemical cleaning. These samples were obtained through the use of the Drop Core Sampler and the Snowbank Sampler developed by the Engineered Equipment & Systems (EES) group of the Savannah River National Laboratory (SRNL).

  17. Lunar Sample Compendium

    NASA Technical Reports Server (NTRS)

    Meyer, Charles

    2005-01-01

    The purpose of the Lunar Sample Compendium will be to inform scientists, astronauts and the public about the various lunar samples that have been returned from the Moon. This Compendium will be organized rock by rock in the manor of a catalog, but will not be as comprehensive, nor as complete, as the various lunar sample catalogs that are available. Likewise, this Compendium will not duplicate the various excellent books and reviews on the subject of lunar samples (Cadogen 1981, Heiken et al. 1991, Papike et al. 1998, Warren 2003, Eugster 2003). However, it is thought that an online Compendium, such as this, will prove useful to scientists proposing to study individual lunar samples and should help provide backup information for lunar sample displays. This Compendium will allow easy access to the scientific literature by briefly summarizing the significant findings of each rock along with the documentation of where the detailed scientific data are to be found. In general, discussion and interpretation of the results is left to the formal reviews found in the scientific literature. An advantage of this Compendium will be that it can be updated, expanded and corrected as need be.

  18. Liquid sampling system

    DOEpatents

    Larson, Loren L.

    1987-01-01

    A conduit extends from a reservoir through a sampling station and back to the reservoir in a closed loop. A jet ejector in the conduit establishes suction for withdrawing liquid from the reservoir. The conduit has a self-healing septum therein upstream of the jet ejector for receiving one end of a double-ended cannula, the other end of which is received in a serum bottle for sample collection. Gas is introduced into the conduit at a gas bleed between the sample collection bottle and the reservoir. The jet ejector evacuates gas from the conduit and the bottle and aspirates a column of liquid from the reservoir at a high rate. When the withdrawn liquid reaches the jet ejector the rate of flow therethrough reduces substantially and the gas bleed increases the pressure in the conduit for driving liquid into the sample bottle, the gas bleed forming a column of gas behind the withdrawn liquid column and interrupting the withdrawal of liquid from the reservoir. In the case of hazardous and toxic liquids, the sample bottle and the jet ejector may be isolated from the reservoir and may be further isolated from a control station containing remote manipulation means for the sample bottle and control valves for the jet ejector and gas bleed.

  19. Liquid sampling system

    DOEpatents

    Larson, L.L.

    1984-09-17

    A conduit extends from a reservoir through a sampling station and back to the reservoir in a closed loop. A jet ejector in the conduit establishes suction for withdrawing liquid from the reservoir. The conduit has a self-healing septum therein upstream of the jet ejector for receiving one end of a double-ended cannula, the other end of which is received in a serum bottle for sample collection. Gas is introduced into the conduit at a gas bleed between the sample collection bottle and the reservoir. The jet ejector evacuates gas from the conduit and the bottle and aspirates a column of liquid from the reservoir at a high rate. When the withdrawn liquid reaches the jet ejector the rate of flow therethrough reduces substantially and the gas bleed increases the pressure in the conduit for driving liquid into the sample bottle, the gas bleed forming a column of gas behind the withdrawn liquid column and interrupting the withdrawal of liquid from the reservoir. In the case of hazardous and toxic liquids, the sample bottle and the jet ejector may be isolated from the reservoir and may be further isolated from a control station containing remote manipulation means for the sample bottle and control valves for the jet ejector and gas bleed. 5 figs.

  20. Sample Return Science

    NASA Astrophysics Data System (ADS)

    Williford, K. H.; Allwood, A.; Beegle, L. W.; Bhartia, R.; Flannery, D.; Hoffmann, A.; Mora, M. F.; Orbay, J.; Petrizzo, D. A.; Tuite, M. L., Jr.; Willis, P. A.

    2014-12-01

    The first clear identification of an ancient habitable environment on Mars by the Mars Science Laboratory (MSL) rover mission relied on a synthetic analytical approach combining orbital and surface imagery and spectroscopy with sophisticated sample acquisition and handling technology including a rotary percussive drill that provided powdered rock for bulk geochemical analysis [1]. The recent announcement of the instrument package for the proposed NASA Mars2020 rover mission, including micro x-ray fluorescence (PIXL) for elemental mapping as well as scanning ultraviolet laser fluorescence and Raman (SHERLOC) suggests a shift in emphasis of Mars surface science towards spatially resolved geochemical analysis that will support the selection and acquisition of samples for coring, caching, and possible return to Earth for further analysis. During a recent field expedition to investigate Archean and Proterozoic biosignatures in the Pilbara region of Western Australia, we deployed a dry, rotary percussive coring drill with a bit assembly analogous to that being considered for Mars2020. Six targets of varying age and lithology were sampled with the coring drill, and surrounding and adjacent rock samples were collected simultaneously. These samples were subsequently prepared and subsampled for bulk and in situ, spatially resolved analysis using conventional laboratory methods as well as the existing PIXL and SHERLOC platforms currently in development. Here we present new approaches and data from this integrated and ongoing program of "sample return science" designed to simulate, and eventually reduce risk associated with a long-term effort towards Mars sample return. [1] Grotzinger, J.P. et al. 2014. Science 343 DOI: 10.1126/science.1242777.

  1. Fluid sampling system

    DOEpatents

    Houck, Edward D.

    1994-01-01

    An fluid sampling system allows sampling of radioactive liquid without spillage. A feed tank is connected to a liquid transfer jet powered by a pumping chamber pressurized by compressed air. The liquid is pumped upwardly into a sampling jet of a venturi design having a lumen with an inlet, an outlet, a constricted middle portion, and a port located above the constricted middle portion. The liquid is passed under pressure through the constricted portion causing its velocity to increase and its pressure to decreased, thereby preventing liquid from escaping. A septum sealing the port can be pierced by a two pointed hollow needle leading into a sample bottle also sealed by a pierceable septum affixed to one end. The bottle is evacuated by flow through the sample jet, cyclic variation in the sampler jet pressure periodically leaves the evacuated bottle with lower pressure than that of the port, thus causing solution to pass into the bottle. The remaining solution in the system is returned to the feed tank via a holding tank.

  2. Fluid sampling system

    DOEpatents

    Houck, E.D.

    1994-10-11

    An fluid sampling system allows sampling of radioactive liquid without spillage. A feed tank is connected to a liquid transfer jet powered by a pumping chamber pressurized by compressed air. The liquid is pumped upwardly into a sampling jet of a venturi design having a lumen with an inlet, an outlet, a constricted middle portion, and a port located above the constricted middle portion. The liquid is passed under pressure through the constricted portion causing its velocity to increase and its pressure to be decreased, thereby preventing liquid from escaping. A septum sealing the port can be pierced by a two pointed hollow needle leading into a sample bottle also sealed by a pierceable septum affixed to one end. The bottle is evacuated by flow through the sample jet, cyclic variation in the sampler jet pressure periodically leaves the evacuated bottle with lower pressure than that of the port, thus causing solution to pass into the bottle. The remaining solution in the system is returned to the feed tank via a holding tank. 4 figs.

  3. Visual Sample Plan

    SciTech Connect

    2007-10-25

    VSP selects the appropriate number and location of environmental samples to ensure that the results of statistical tests performed to provide input to risk decisions have the required confidence and performance. VSP Version 5.0 provides sample-size equations or algorithms needed by specific statistical tests appropriate for specific environmental sampling objectives. It also provides data quality assessment and statistical analysis functions to support evaluation of the data and determine whether the data support decisions regarding sites suspected of contamination. The easy-to-use program is highly visual and graphic. VSP runs on personal computers with Microsoft Windows operating systems (98, NT, 2000, Millennium Edition, CE, and XP) Designed primarily for project managers and users without expertise in statistics, VSP is applicable to two- and three-dimensional populations to be sampled (e.g., rooms and buildings, surface soil, a defined layer of subsurface soil, water bodies, and other similar applications) for studies of environmental quality. VSP is also applicable for designing sampling plans for assessing chem./rad/bio threat and hazard identification within rooms and buildings, and for designing geophysical surveys for UXO identification.

  4. Visual Sample Plan

    2007-10-25

    VSP selects the appropriate number and location of environmental samples to ensure that the results of statistical tests performed to provide input to risk decisions have the required confidence and performance. VSP Version 5.0 provides sample-size equations or algorithms needed by specific statistical tests appropriate for specific environmental sampling objectives. It also provides data quality assessment and statistical analysis functions to support evaluation of the data and determine whether the data support decisions regarding sitesmore » suspected of contamination. The easy-to-use program is highly visual and graphic. VSP runs on personal computers with Microsoft Windows operating systems (98, NT, 2000, Millennium Edition, CE, and XP) Designed primarily for project managers and users without expertise in statistics, VSP is applicable to two- and three-dimensional populations to be sampled (e.g., rooms and buildings, surface soil, a defined layer of subsurface soil, water bodies, and other similar applications) for studies of environmental quality. VSP is also applicable for designing sampling plans for assessing chem./rad/bio threat and hazard identification within rooms and buildings, and for designing geophysical surveys for UXO identification.« less

  5. Fluid sampling system

    SciTech Connect

    Houck, E.D.

    1993-12-31

    This invention comprises a fluid sampling system which allows sampling of radioactive liquid without spillage. A feed tank is connected to a liquid transfer jet powered by a pumping chamber pressurized by compressed air. The liquid is pumped up into a sampling jet of venturi design having a lumen with an inlet, an outlet, a constricted middle portion, and a port located above the constricted middle portion. The liquid is passed under pressure through the constricted portion causing its velocity to increase and its pressure to decrease, thereby preventing liquid from escaping. A septum sealing the port can be pierced by a two pointed hollow needle leading into a sample bottle also sealed by a pierceable septum affixed to one end. The bottle is evacuated by flow through the sample jet, cyclic variation in the sampler jet pressure periodicially leaves the evacuated bottle with lower pressure than that of the port, thus causing solution to pass into the bottle. The remaining solution in the system is returned to the feed tank via a holding tank.

  6. Core sample extractor

    NASA Technical Reports Server (NTRS)

    Akins, James; Cobb, Billy; Hart, Steve; Leaptrotte, Jeff; Milhollin, James; Pernik, Mark

    1989-01-01

    The problem of retrieving and storing core samples from a hole drilled on the lunar surface is addressed. The total depth of the hole in question is 50 meters with a maximum diameter of 100 millimeters. The core sample itself has a diameter of 60 millimeters and will be two meters in length. It is therefore necessary to retrieve and store 25 core samples per hole. The design utilizes a control system that will stop the mechanism at a certain depth, a cam-linkage system that will fracture the core, and a storage system that will save and catalogue the cores to be extracted. The Rod Changer and Storage Design Group will provide the necessary tooling to get into the hole as well as to the core. The mechanical design for the cam-linkage system as well as the conceptual design of the storage device are described.

  7. Experimental scattershot boson sampling

    PubMed Central

    Bentivegna, Marco; Spagnolo, Nicolò; Vitelli, Chiara; Flamini, Fulvio; Viggianiello, Niko; Latmiral, Ludovico; Mataloni, Paolo; Brod, Daniel J.; Galvão, Ernesto F.; Crespi, Andrea; Ramponi, Roberta; Osellame, Roberto; Sciarrino, Fabio

    2015-01-01

    Boson sampling is a computational task strongly believed to be hard for classical computers, but efficiently solvable by orchestrated bosonic interference in a specialized quantum computer. Current experimental schemes, however, are still insufficient for a convincing demonstration of the advantage of quantum over classical computation. A new variation of this task, scattershot boson sampling, leads to an exponential increase in speed of the quantum device, using a larger number of photon sources based on parametric down-conversion. This is achieved by having multiple heralded single photons being sent, shot by shot, into different random input ports of the interferometer. We report the first scattershot boson sampling experiments, where six different photon-pair sources are coupled to integrated photonic circuits. We use recently proposed statistical tools to analyze our experimental data, providing strong evidence that our photonic quantum simulator works as expected. This approach represents an important leap toward a convincing experimental demonstration of the quantum computational supremacy. PMID:26601164

  8. Experimental scattershot boson sampling.

    PubMed

    Bentivegna, Marco; Spagnolo, Nicolò; Vitelli, Chiara; Flamini, Fulvio; Viggianiello, Niko; Latmiral, Ludovico; Mataloni, Paolo; Brod, Daniel J; Galvão, Ernesto F; Crespi, Andrea; Ramponi, Roberta; Osellame, Roberto; Sciarrino, Fabio

    2015-04-01

    Boson sampling is a computational task strongly believed to be hard for classical computers, but efficiently solvable by orchestrated bosonic interference in a specialized quantum computer. Current experimental schemes, however, are still insufficient for a convincing demonstration of the advantage of quantum over classical computation. A new variation of this task, scattershot boson sampling, leads to an exponential increase in speed of the quantum device, using a larger number of photon sources based on parametric down-conversion. This is achieved by having multiple heralded single photons being sent, shot by shot, into different random input ports of the interferometer. We report the first scattershot boson sampling experiments, where six different photon-pair sources are coupled to integrated photonic circuits. We use recently proposed statistical tools to analyze our experimental data, providing strong evidence that our photonic quantum simulator works as expected. This approach represents an important leap toward a convincing experimental demonstration of the quantum computational supremacy.

  9. Viscous sludge sample collector

    DOEpatents

    Beitel, George A [Richland, WA

    1983-01-01

    A vertical core sample collection system for viscous sludge. A sample tube's upper end has a flange and is attached to a piston. The tube and piston are located in the upper end of a bore in a housing. The bore's lower end leads outside the housing and has an inwardly extending rim. Compressed gas, from a storage cylinder, is quickly introduced into the bore's upper end to rapidly accelerate the piston and tube down the bore. The lower end of the tube has a high sludge entering velocity to obtain a full-length sludge sample without disturbing strata detail. The tube's downward motion is stopped when its upper end flange impacts against the bore's lower end inwardly extending rim.

  10. Thermoluminescence of lunar samples

    USGS Publications Warehouse

    Dalrymple, G.B.; Doell, Richard R.

    1970-01-01

    Appreciable natural thermoluminescence with glow curve peaks at about 350 degrees centigrade for lunar fines and breccias and above 400 degrees centigrade for crystalline rocks has been recognized in lunar samples. Plagioclase has been identified as the principal carrier of thermoluminescence, and the difference in peak temperatures indicates compositional or structural differences between the feldspars of the different rock types. The present thermoluminescence in the lunar samples is probably the result of a dynamic equilibrium between acquisition from radiation and loss in the lunar thermal environment. A progressive change in the glow curves of core samples with depth below the surface suggests the use of thermoluminescence disequilibrium to detect surfaces buried by recent surface activity, and it also indicates that the lunar diurnal temperature variation penetrates to at least 10.5 centimeters.

  11. Sampling in landscape genomics.

    PubMed

    Manel, Stéphanie; Albert, Cécile H; Yoccoz, Nigel G

    2012-01-01

    Landscape genomics, based on the sampling of individuals genotyped for a large number of markers, may lead to the identification of regions of the genome correlated to selection pressures caused by the environment. In this chapter, we discuss sampling strategies to be used in a landscape genomics approach. We suggest that designs based on model-based stratification using the climatic and/or biological spaces are in general more efficient than designs based on the geographic space. More work is needed to identify designs that allow disentangling environmental selection pressures versus other processes such as range expansions or hierarchical population structure.

  12. Returning Samples from Enceladus

    NASA Astrophysics Data System (ADS)

    Tsou, P.; Kanik, I.; Brownlee, D.; McKay, C.; Anbar, A.; Glavin, D.; Yano, H.

    2012-12-01

    From the first half century of space exploration, we have obtained samples only from the Moon, comet Wild 2, the Solar Wind and the asteroid Itokawa. The in-depth analyses of these samples in terrestrial laboratories have yielded profound knowledge that could not have been obtained without the returned samples. While obtaining samples from Solar System bodies is crucial science, it is rarely done due to cost and complexity. Cassini's discovery of geysers on Enceladus and organic materials, indicate that there is an exceptional opportunity and science rational to do a low-cost flyby sample return mission, similar to what was done by the Stardust. The earliest low cost possible flight opportunity is the next Discovery Mission [Tsou et al 2012]. Enceladus Plume Discovery - While Voyager provided evidence for young surfaces on Enceladus, the existence of Enceladus plumes was discovered by Cassini. Enceladus and comets are the only known solar system bodies that have jets enabling sample collection without landing or surface contact. Cassini in situ Findings -Cassini's made many discoveries at Saturn, including the break up of large organics in the plumes of Enceladus. Four prime criteria for habitability are liquid water, a heat source, organics and nitrogen [McKay et al. 2008, Waite et al. 2009, Postberg et al. 2011]. Out of all the NASA designated habitability targets, Enceladus is the single body that presents evidence for all four criteria. Significant advancement in the exploration of the biological potential of Enceladus can be made on returned samples in terrestrial laboratories where the full power of state-of-the-art laboratory instrumentation and procedures can be used. Without serious limits on power, mass or even cost, terrestrial laboratories provide the ultimate in analytical capability, adaptability, reproducibility and reliability. What Questions can Samples Address? - Samples collected from the Enceladus plume will enable a thorough and replicated

  13. Lunar sample analysis

    NASA Technical Reports Server (NTRS)

    Housley, R. M.

    1978-01-01

    Flameless atomic abosrption, X-ray photoemission spectroscopy, ferromagnetic resonance, scanning electron microscopy, and Moessbauer spectroscopy were used to investigate the evolution of the lunar regolith, the transport of volatile trace metals, and the surface composition of lunar samples. The development of a model for lunar volcanic eruptions is also discussed.

  14. Groundwater sampling: Chapter 5

    USGS Publications Warehouse

    Wang, Qingren; Munoz-Carpena, Rafael; Foster, Adam; Migliaccio, Kati W.; Li, Yuncong; Migliaccio, Kati

    2011-01-01

    Discussing an array of water quality topics, from water quality regulations and criteria, to project planning and sampling activities, this book outlines a framework for improving water quality programs. Using this framework, you can easily put the proper training and tools in place for better management of water resources.

  15. Robotic nuclear sample management

    SciTech Connect

    Hollen, R.M.; Beugelsdijk, T.J.; Temer, D.J.; Hopkins, V.A.

    1987-01-01

    The Analytical Chemistry Group of the Los Alamos National Laboratory processes in excess of 4000 plutonium metal samples each year. Depending on what specific elements are to be determined, each sample must be cut into fractions for distribution to the various task areas for specific analyses in areas such as mass spectrometry. A unique laboratory automation system has been developed based on a commercially available Zymate II robot. The robot consists of a central arm that operates in a hollow cylindrical work envelop and has four degrees of freedom. Accessible to the arm are standard Zymark laboratory stations, which include an analytical balance, a reagent dispensing station, a capping station, and vial racks. Custom stations designed and constructed by an in-house robotics group for corrosive environments include a vial capping station, a pipette tip shucker, and a vial dispenser. Initial reliability testing is currently in progress. Copper metal samples are being used in lieu of plutonium to identify areas in which mechanical adjustments are needed or in which the software needs modification. The system is projected to be commissioned during January 1988. Future plane include the addition of capabilities to accommodate plutonium oxide samples.

  16. [Samples in Coagulation Test].

    PubMed

    Komiyama, Yutaka

    2015-12-01

    An understanding and ability to develop a strategy to prevent pre-analytical errors of laboratory tests in the hemostasis area are two of the most important skills of medical technologists and related doctors. Recently, the working group for standardization of sampling in coagulation tests is working towards a consensus. This article reviews a summary of the consensus: (1) The anticoagulant for coagulation tests is 3.13-3.2% sodium citrate at a ratio of 1:9 to whole blood and the accuracy of the ratio is within 10%. (2) Blood sampling is achieved with the use of a 21-23G needle and coagulation. Blood sampling can be achieved by both a syringe and vacuum tube system. After taking blood, laboratory tests such as of the prothrombin time (PT) and activated partial thromboplastin time (APTT) should be completed within one hour and the storage temperature should be at room temperature, not ice-cold conditions. 3) To prepare a plasma sample, citrated blood is centrifuged at 1,500 x g for 15 min at room temperature to minimize the remaining platelets in plasma (below 10,000/microL at least).

  17. Adaptive Sampling Designs.

    ERIC Educational Resources Information Center

    Flournoy, Nancy

    Designs for sequential sampling procedures that adapt to cumulative information are discussed. A familiar illustration is the play-the-winner rule in which there are two treatments; after a random start, the same treatment is continued as long as each successive subject registers a success. When a failure occurs, the other treatment is used until…

  18. Sampling for Chemical Analysis.

    ERIC Educational Resources Information Center

    Kratochvil, Byron; And Others

    1984-01-01

    This review, designed to make analysts aware of uncertainties introduced into analytical measurements during sampling, is organized under these headings: general considerations; theory; standards; and applications related to mineralogy, soils, sediments, metallurgy, atmosphere, water, biology, agriculture and food, medical and clinical areas, oil…

  19. Randomization and sampling issues

    USGS Publications Warehouse

    Geissler, P.H.

    1996-01-01

    The need for randomly selected routes and other sampling issues have been debated by the Amphibian electronic discussion group. Many excellent comments have been made, pro and con, but we have not reached consensus yet. This paper brings those comments together and attempts a synthesis. I hope that the resulting discussion will bring us closer to a consensus.

  20. Drafting Work Sample.

    ERIC Educational Resources Information Center

    Shawsheen Valley Regional Vocational-Technical High School, Billerica, MA.

    This manual contains a work sample intended to assess a handicapped student's interest in and to screen interested students into a training program in basic mechanical drawing. (The course is based on the entry level of an assistant drafter.) Section 1 describes the assessment, correlates the work performed and worker traits required for…

  1. Using Language Sample Databases

    ERIC Educational Resources Information Center

    Heilmann, John J.; Miller, Jon F.; Nockerts, Ann

    2010-01-01

    Purpose: Over the past 50 years, language sample analysis (LSA) has evolved from a powerful research tool that is used to document children's linguistic development into a powerful clinical tool that is used to identify and describe the language skills of children with language impairment. The Systematic Analysis of Language Transcripts (SALT; J.…

  2. Minimum variance geographic sampling

    NASA Technical Reports Server (NTRS)

    Terrell, G. R. (Principal Investigator)

    1980-01-01

    Resource inventories require samples with geographical scatter, sometimes not as widely spaced as would be hoped. A simple model of correlation over distances is used to create a minimum variance unbiased estimate population means. The fitting procedure is illustrated from data used to estimate Missouri corn acreage.

  3. ANNULAR IMPACTOR SAMPLING DEVICE

    DOEpatents

    Tait, G.W.C.

    1959-03-31

    A high-rate air sampler capable of sampling alphaemitting particles as small as 0.5 microns is described. The device is a cylindrical shaped cup that fits in front of a suction tube and which has sticky grease coating along its base. Suction forces contaminated air against the periodically monitored particle absorbing grease.

  4. Monitoring MRK 509: The Origin of the Reprocessor and Broad Band X-ray Spectrum of Narrow Line Seyfert 1 AKN 564

    NASA Technical Reports Server (NTRS)

    Halpern, Jules P.; Leighly, Karen M.

    1998-01-01

    The ten monitoring observations of Mrk 509 were made successfully between October 20 and November 26 last year. These observations were simultaneously with RXTE observations. A preliminary analysis of the RXTE observations has been done, and the light curve is shown in figure 1. Our aim in this experiment is to determine the location of the emission region of the reflection component by reverberation mapping. This component could be emitted from the accretion disk, within 100 Scwartzschild radii (R(sub s)) from the source. Note that the monitoring interval of 2.5 days corresponds to 100 R(sub s) for a 2 x 10(exp 8) solar mass black hole, which may be appropriate for this luminous object. In that case, we would expect the reflected component to vary along the direct flux, and there should be no spectral variability between observations. Alternatively, the reflected emission could come from the molecular torus, several parsecs from the nucleus. In that case, the reflection component flux should not vary. The light curve in figure 1 shows that during the monitoring period, the target varied in an ideal way, since significant variability was observed between observations and yet the most rapid variability is apparently sampled. The analysis of this data is not yet completed. The measurement of the reflection component in the combined ASCa and RXTE spectra depends critically on the RXTE background subtraction and calibration, but these have not yet progressed to the point where the analysis can be done.

  5. SUBMILLIMETER ARRAY/PLATEAU DE BURE INTERFEROMETER MULTIPLE LINE OBSERVATIONS OF THE NEARBY SEYFERT 2 GALAXY NGC 1068: SHOCK-RELATED GAS KINEMATICS AND HEATING IN THE CENTRAL 100 pc?

    SciTech Connect

    Krips, M.; Neri, R.; Martin, S. E-mail: neri@iram.fr

    2011-07-20

    We present high angular resolution (0.''5-2.''0) observations of the millimeter continuum and the {sup 12}CO(J = 3-2), {sup 13}CO(J = 3-2), {sup 13}CO(J = 2-1), C{sup 18}O(J = 2-1), HCN(J = 3-2), HCO{sup +}(J = 4-3), and HCO{sup +}(J = 3-2) line emission in the circumnuclear disk (r {approx}< 100 pc) of the prototypical Seyfert 2 galaxy NGC 1068, carried out with the Submillimeter Array. We also include in our analysis new {sup 13}CO(J = 1-0) and improved {sup 12}CO(J = 2-1) observations of NGC 1068 at high angular resolution (1.''0-2.''0) and sensitivity, conducted with the Institute de Radioastronomie Millimetrique Plateau de Bure Interferometer. Based on the complex dynamics of the molecular gas emission indicating non-circular motions in the central {approx}100 pc, we propose a scenario in which part of the molecular gas in the circumnuclear disk of NGC 1068 is blown radially outward as a result of shocks. This shock scenario is further supported by quite warm (T{sub kin} {>=} 200 K) and dense (n(H{sub 2}) {approx_equal} 10{sup 4} cm{sup -3}) gas constrained from observed molecular line ratios. The HCN abundance in the circumnuclear disk is found to be [HCN]/[{sup 12}CO] {approx} 10{sup -3.5}. This is slightly higher than the abundances derived for Galactic and extragalactic star-forming/starbursting regions. This result lends further support to X-ray-enhanced HCN formation in the circumnuclear disk of NGC 1068 as suggested by earlier studies. The HCO{sup +} abundance ([HCO{sup +}]/[{sup 12}CO] {approx} 10{sup -5}) appears to be somewhat lower than that of Galactic and extragalactic star-forming/starbursting regions. When trying to fit the centimeter-to-millimeter continuum emission by different thermal and non-thermal processes, it appears that electron-scattered synchrotron emission yields the best results while thermal free-free emission seems to overpredict the millimeter continuum emission.

  6. Comparative sampling molds evaluation

    SciTech Connect

    Pierrard, L.; Jarry, P.; Charbonnier, J.; Rigaut, C.

    1996-10-01

    The metallurgical industry needs to cast alloys with narrow tolerances in their chemical composition in order to reduce variability of their use properties. Therefore appropriate sampling practices and analytical methods are required. Both accuracy and precision of the analytical results are limited by the non-homogeneity of as-cast disk or cylinder samples, which results from macrosegregation phenomenon. This paper presents a comparison between six commonly used molds: four molds recommended by ASTM standards (center-pour molds type B and vacuum mold), mushroom shaped and cylinder molds. Two complementary approaches are exhibited for the different molds designs: (1) solidification modeling in order to predict macrosegregation localization using the Simulor software; (2) experimental characterization. Radial and axial segregation profiles are determined by Analytical Scanning Electron Microscopy in addition to analytical precision evaluation by spark optical emission and X-Ray fluorescence spectrometries for a given machining depth.

  7. Seabed observation & sampling system

    USGS Publications Warehouse

    Blackwood, D.; Parolski, K.

    2001-01-01

    SEABOSS has proved to be a valuable addition to the USGS data-acquisition and processing field program. It has allowed researchers to collect high-quality images and seabed samples in a timely manner. It is a simple, dependable and trouble-free system with a track record of over 3,000 deployments. When used as part of the USGS seafloor mapping acquisition, processing, and ground-truth program, SEABOSS has been invaluable in providing information quickly and efficiently, with a minimum of downtime. SEABOSS enables scientists to collect high-quality images and samples of the seabed, essential to the study of sedimentary environments and biological habitats and to the interpretation of side-scan sonar and multibeam imagery, the most common tools for mapping the seabed.

  8. Nonadiabatic transition path sampling

    NASA Astrophysics Data System (ADS)

    Sherman, M. C.; Corcelli, S. A.

    2016-07-01

    Fewest-switches surface hopping (FSSH) is combined with transition path sampling (TPS) to produce a new method called nonadiabatic path sampling (NAPS). The NAPS method is validated on a model electron transfer system coupled to a Langevin bath. Numerically exact rate constants are computed using the reactive flux (RF) method over a broad range of solvent frictions that span from the energy diffusion (low friction) regime to the spatial diffusion (high friction) regime. The NAPS method is shown to quantitatively reproduce the RF benchmark rate constants over the full range of solvent friction. Integrating FSSH within the TPS framework expands the applicability of both approaches and creates a new method that will be helpful in determining detailed mechanisms for nonadiabatic reactions in the condensed-phase.

  9. Water sample filtration unit

    USGS Publications Warehouse

    Skougstad, M.W.; Scarbro, G.F.

    1968-01-01

    A readily portable, all plastic, pressure filtration unit is described which greatly facilitates rapid micropore membrane field filtration of up to several liters of water with a minimum risk of inorganic chemical alteration or contamination of the sample. The unit accommodates standard 10.2-cm. (4-inch) diameter filters. The storage and carrying case serves as a convenient filter stand for both field and laboratory use.

  10. Advanced hierarchical distance sampling

    USGS Publications Warehouse

    Royle, Andy

    2016-01-01

    In this chapter, we cover a number of important extensions of the basic hierarchical distance-sampling (HDS) framework from Chapter 8. First, we discuss the inclusion of “individual covariates,” such as group size, in the HDS model. This is important in many surveys where animals form natural groups that are the primary observation unit, with the size of the group expected to have some influence on detectability. We also discuss HDS integrated with time-removal and double-observer or capture-recapture sampling. These “combined protocols” can be formulated as HDS models with individual covariates, and thus they have a commonality with HDS models involving group structure (group size being just another individual covariate). We cover several varieties of open-population HDS models that accommodate population dynamics. On one end of the spectrum, we cover models that allow replicate distance sampling surveys within a year, which estimate abundance relative to availability and temporary emigration through time. We consider a robust design version of that model. We then consider models with explicit dynamics based on the Dail and Madsen (2011) model and the work of Sollmann et al. (2015). The final major theme of this chapter is relatively newly developed spatial distance sampling models that accommodate explicit models describing the spatial distribution of individuals known as Point Process models. We provide novel formulations of spatial DS and HDS models in this chapter, including implementations of those models in the unmarked package using a hack of the pcount function for N-mixture models.

  11. Digital Microfluidics Sample Analyzer

    NASA Technical Reports Server (NTRS)

    Pollack, Michael G.; Srinivasan, Vijay; Eckhardt, Allen; Paik, Philip Y.; Sudarsan, Arjun; Shenderov, Alex; Hua, Zhishan; Pamula, Vamsee K.

    2010-01-01

    Three innovations address the needs of the medical world with regard to microfluidic manipulation and testing of physiological samples in ways that can benefit point-of-care needs for patients such as premature infants, for which drawing of blood for continuous tests can be life-threatening in their own right, and for expedited results. A chip with sample injection elements, reservoirs (and waste), droplet formation structures, fluidic pathways, mixing areas, and optical detection sites, was fabricated to test the various components of the microfluidic platform, both individually and in integrated fashion. The droplet control system permits a user to control droplet microactuator system functions, such as droplet operations and detector operations. Also, the programming system allows a user to develop software routines for controlling droplet microactuator system functions, such as droplet operations and detector operations. A chip is incorporated into the system with a controller, a detector, input and output devices, and software. A novel filler fluid formulation is used for the transport of droplets with high protein concentrations. Novel assemblies for detection of photons from an on-chip droplet are present, as well as novel systems for conducting various assays, such as immunoassays and PCR (polymerase chain reaction). The lab-on-a-chip (a.k.a., lab-on-a-printed-circuit board) processes physiological samples and comprises a system for automated, multi-analyte measurements using sub-microliter samples of human serum. The invention also relates to a diagnostic chip and system including the chip that performs many of the routine operations of a central labbased chemistry analyzer, integrating, for example, colorimetric assays (e.g., for proteins), chemiluminescence/fluorescence assays (e.g., for enzymes, electrolytes, and gases), and/or conductometric assays (e.g., for hematocrit on plasma and whole blood) on a single chip platform.

  12. Sustainable Mars Sample Return

    NASA Technical Reports Server (NTRS)

    Alston, Christie; Hancock, Sean; Laub, Joshua; Perry, Christopher; Ash, Robert

    2011-01-01

    The proposed Mars sample return mission will be completed using natural Martian resources for the majority of its operations. The system uses the following technologies: In-Situ Propellant Production (ISPP), a methane-oxygen propelled Mars Ascent Vehicle (MAV), a carbon dioxide powered hopper, and a hydrogen fueled balloon system (large balloons and small weather balloons). The ISPP system will produce the hydrogen, methane, and oxygen using a Sabatier reactor. a water electrolysis cell, water extracted from the Martian surface, and carbon dioxide extracted from the Martian atmosphere. Indigenous hydrogen will fuel the balloon systems and locally-derived methane and oxygen will fuel the MAV for the return of a 50 kg sample to Earth. The ISPP system will have a production cycle of 800 days and the estimated overall mission length is 1355 days from Earth departure to return to low Earth orbit. Combining these advanced technologies will enable the proposed sample return mission to be executed with reduced initial launch mass and thus be more cost efficient. The successful completion of this mission will serve as the next step in the advancement of Mars exploration technology.

  13. 340 representative sampling verification tank sampling and analysis plan

    SciTech Connect

    Halgren, D.L., Westinghouse Hanford

    1996-09-09

    This Sampling and Analysis Plan contains requirements for characterizing the 340 vault tank 1. The objective of the sampling and characterization is to determine if the tank is homogeneous when agitated and which sampling method provides the most representative sample. A secondary objective is to collect and characterize solid samples.

  14. 340 Representative sampling verification tank sampling and analysis plan

    SciTech Connect

    Olander, A.R., Westinghouse Hanford

    1996-08-07

    This Sampling and Analysis Plan contains requirements for characterizing the 340 vault tank 1. The objective of the sampling and characterization is to determine if the tank is homogeneous when agitated and which sampling method provides the most representative sample. A secondary objective is to collect and characterize solid samples.

  15. 340 Representative sampling verification tank sampling and analysis plan

    SciTech Connect

    Olander, A.R., Westinghouse Hanford

    1996-08-21

    This Sampling and Analysis Plan contains requirements for characterizing the 340 vault tank 1. The objective of the sampling and characterization is to determine if the tank is homogeneous when agitated and which sampling method provides the most representative sample. A secondary objective is to collect and characterize solid samples.

  16. 40 CFR 1065.1107 - Sample media and sample system preparation; sample system assembly.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Sample media and sample system... Special Pollutants Semi-Volatile Organic Compounds § 1065.1107 Sample media and sample system preparation; sample system assembly. This section describes the appropriate types of sample media and the...

  17. A New Sample of Candidate Intermediate-mass Black Holes Selected by X-Ray Variability

    NASA Astrophysics Data System (ADS)

    Kamizasa, Naoya; Terashima, Yuichi; Awaki, Hisamitsu

    2012-05-01

    We present the results of X-ray variability and spectral analysis of a sample of 15 new candidates for active galactic nuclei with relatively low-mass black holes (BHs). They are selected from the Second XMM-Newton Serendipitous Source Catalogue based on strong variability quantified by normalized excess variances. Their BH masses are estimated to be (1.1-6.6) × 106 M ⊙ by using a correlation between excess variance and BH mass. Seven sources have estimated BH masses smaller than 2 × 106 M ⊙, which are in the range for intermediate-mass black holes. Eddington ratios of sources with known redshifts range from 0.07 to 0.46 and the mean Eddington ratio is 0.24. These results imply that some of our sources are growing supermassive black holes, which are expected to have relatively low masses with high Eddington ratios. X-ray photon indices of the 15 sources are in the range of ≈0.57-2.57 and 5 among them have steep (>2) photon indices, which are the range for narrow-line Seyfert 1s. Soft X-ray excess is seen in 12 sources and is expressed by a blackbody model with kT ≈ 83-294 eV. We derive a correlation between X-ray photon indices and Eddington ratios, and find that the X-ray photon indices of about a half of our sources are flatter than the positive correlation suggested previously. Based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and NASA.

  18. NID Copper Sample Analysis

    SciTech Connect

    Kouzes, Richard T.; Zhu, Zihua

    2011-09-12

    The current focal point of the nuclear physics program at PNNL is the MAJORANA DEMONSTRATOR, and the follow-on Tonne-Scale experiment, a large array of ultra-low background high-purity germanium detectors, enriched in 76Ge, designed to search for zero-neutrino double-beta decay (0νββ). This experiment requires the use of germanium isotopically enriched in 76Ge. The MAJORANA DEMONSTRATOR is a DOE and NSF funded project with a major science impact. The DEMONSTRATOR will utilize 76Ge from Russia, but for the Tonne-Scale experiment it is hoped that an alternate technology, possibly one under development at Nonlinear Ion Dynamics (NID), will be a viable, US-based, lower-cost source of separated material. Samples of separated material from NID require analysis to determine the isotopic distribution and impurities. DOE is funding NID through an SBIR grant for development of their separation technology for application to the Tonne-Scale experiment. The Environmental Molecular Sciences facility (EMSL), a DOE user facility at PNNL, has the required mass spectroscopy instruments for making isotopic measurements that are essential to the quality assurance for the MAJORANA DEMONSTRATOR and for the development of the future separation technology required for the Tonne-Scale experiment. A sample of isotopically separated copper was provided by NID to PNNL in January 2011 for isotopic analysis as a test of the NID technology. The results of that analysis are reported here. A second sample of isotopically separated copper was provided by NID to PNNL in August 2011 for isotopic analysis as a test of the NID technology. The results of that analysis are also reported here.

  19. Stack sampling apparatus

    DOEpatents

    Lind, Randall F; Lloyd, Peter D; Love, Lonnie J; Noakes, Mark W; Pin, Francois G; Richardson, Bradley S; Rowe, John C

    2014-09-16

    An apparatus for obtaining samples from a structure includes a support member, at least one stabilizing member, and at least one moveable member. The stabilizing member has a first portion coupled to the support member and a second portion configured to engage with the structure to restrict relative movement between the support member and the structure. The stabilizing member is radially expandable from a first configuration where the second portion does not engage with a surface of the structure to a second configuration where the second portion engages with the surface of the structure.

  20. Pulsed field sample neutralization

    DOEpatents

    Appelhans, Anthony D.; Dahl, David A.; Delmore, James E.

    1990-01-01

    An apparatus and method for alternating voltage and for varying the rate of extraction during the extraction of secondary particles, resulting in periods when either positive ions, or negative ions and electrons are extracted at varying rates. Using voltage with alternating charge during successive periods to extract particles from materials which accumulate charge opposite that being extracted causes accumulation of surface charge of opposite sign. Charge accumulation can then be adjusted to a ratio which maintains a balance of positive and negative charge emission, thus maintaining the charge neutrality of the sample.

  1. Phobos Sample Return mission

    NASA Astrophysics Data System (ADS)

    Zelenyi, Lev; Zakharov, A.; Martynov, M.; Polischuk, G.

    Very mysterious objects of the Solar system are the Martian satellites, Phobos and Deimos. Attempt to study Phobos in situ from an orbiter and from landers have been done by the Russian mission FOBOS in 1988. However, due to a malfunction of the onboard control system the landers have not been delivered to the Phobos surface. A new robotics mission to Phobos is under development now in Russia. Its main goal is the delivery of samples of the Phobos surface material to the Earth for laboratory studies of its chemical, isotopic, mineral composition, age etc. Other goals are in situ studies of Phobos (regolith, internal structure, peculiarities in orbital and proper rotation), studies of Martian environment (dust, plasma, fields). The payload includes a number of scientific instruments: gamma and neutron spectrometers, gaschromatograph, mass spectrometers, IR spectrometer, seismometer, panoramic camera, dust sensor, plasma package. To implement the tasks of this mission a cruise-transfer spacecraft after the launch and the Earth-Mars interplanetary flight will be inserted into the first elliptical orbit around Mars, then after several corrections the spacecraft orbit will be formed very close to the Phobos orbit to keep the synchronous orbiting with Phobos. Then the spacecraft will encounter with Phobos and will land at the surface. After the landing the sampling device of the spacecraft will collect several samples of the Phobos regolith and will load these samples into the return capsule mounted at the returned vehicle. This returned vehicle will be launched from the mother spacecraft and after the Mars-Earth interplanetary flight after 11 monthes with reach the terrestrial atmosphere. Before entering into the atmosphere the returned capsule will be separated from the returned vehicle and will hopefully land at the Earth surface. The mother spacecraft at the Phobos surface carrying onboard scientific instruments will implement the "in situ" experiments during an year

  2. 46. VIEW OF SAMPLING ROOM FROM SOUTHEAST. TO LEFT, SAMPLING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    46. VIEW OF SAMPLING ROOM FROM SOUTHEAST. TO LEFT, SAMPLING ELEVATOR AND IN CENTER, SAMPLE BINS WITH DISCHARGE CHUTE AND THREE LABELS. - Bald Mountain Gold Mill, Nevada Gulch at head of False Bottom Creek, Lead, Lawrence County, SD

  3. NID Copper Sample Analysis

    SciTech Connect

    Kouzes, Richard T.; Zhu, Zihua

    2011-02-01

    The current focal point of the nuclear physics program at PNNL is the MAJORANA DEMONSTRATOR, and the follow-on Tonne-Scale experiment, a large array of ultra-low background high-purity germanium detectors, enriched in 76Ge, designed to search for zero-neutrino double-beta decay (0νββ). This experiment requires the use of germanium isotopically enriched in 76Ge. The DEMONSTRATOR will utilize 76Ge from Russia, but for the Tonne-Scale experiment it is hoped that an alternate technology under development at Nonlinear Ion Dynamics (NID) will be a viable, US-based, lower-cost source of separated material. Samples of separated material from NID require analysis to determine the isotopic distribution and impurities. The MAJORANA DEMONSTRATOR is a DOE and NSF funded project with a major science impact. DOE is funding NID through an SBIR grant for development of their separation technology for application to the Tonne-Scale experiment. The Environmental Molecular Sciences facility (EMSL), a DOE user facility at PNNL, has the required mass spectroscopy instruments for making these isotopic measurements that are essential to the quality assurance for the MAJORANA DEMONSTRATOR and for the development of the future separation technology required for the Tonne-Scale experiment. A sample of isotopically separated copper was provided by NID to PNNL for isotopic analysis as a test of the NID technology. The results of that analysis are reported here.

  4. Fluid sampling tool

    DOEpatents

    Garcia, Anthony R.; Johnston, Roger G.; Martinez, Ronald K.

    1999-05-25

    A fluid sampling tool for sampling fluid from a container. The tool has a fluid collecting portion which is drilled into the container wall, thereby affixing it to the wall. The tool may have a fluid extracting section which withdraws fluid collected by the fluid collecting section. The fluid collecting section has a fluted shank with an end configured to drill a hole into a container wall. The shank has a threaded portion for tapping the borehole. The shank is threadably engaged to a cylindrical housing having an inner axial passageway sealed at one end by a septum. A flexible member having a cylindrical portion and a bulbous portion is provided. The housing can be slid into an inner axial passageway in the cylindrical portion and sealed to the flexible member. The bulbous portion has an outer lip defining an opening. The housing is clamped into the chuck of a drill, the lip of the bulbous section is pressed against a container wall until the shank touches the wall, and the user operates the drill. Wall shavings (kerf) are confined in a chamber formed in the bulbous section as it folds when the shank advances inside the container. After sufficient advancement of the shank, an o-ring makes a seal with the container wall.

  5. Fluid sampling tool

    DOEpatents

    Garcia, A.R.; Johnston, R.G.; Martinez, R.K.

    1999-05-25

    A fluid sampling tool is described for sampling fluid from a container. The tool has a fluid collecting portion which is drilled into the container wall, thereby affixing it to the wall. The tool may have a fluid extracting section which withdraws fluid collected by the fluid collecting section. The fluid collecting section has a fluted shank with an end configured to drill a hole into a container wall. The shank has a threaded portion for tapping the borehole. The shank is threadably engaged to a cylindrical housing having an inner axial passageway sealed at one end by a septum. A flexible member having a cylindrical portion and a bulbous portion is provided. The housing can be slid into an inner axial passageway in the cylindrical portion and sealed to the flexible member. The bulbous portion has an outer lip defining an opening. The housing is clamped into the chuck of a drill, the lip of the bulbous section is pressed against a container wall until the shank touches the wall, and the user operates the drill. Wall shavings (kerf) are confined in a chamber formed in the bulbous section as it folds when the shank advances inside the container. After sufficient advancement of the shank, an o-ring makes a seal with the container wall. 6 figs.

  6. A sample of active galactic nuclei with strong soft X-ray variabilities

    NASA Astrophysics Data System (ADS)

    Bi, Da; Liu, Teng; Wang, JunXian

    2015-04-01

    Large-amplitude X-ray variation is a special feature of AGN, reflecting possible extreme change in the central engine or the absorption along the line of sight. Till now there are only a few relevant studies on individual sources or rather small samples. In this work we aim to perform a systematic study of AGNs with strong soft X-ray variations at timescale of ≳ 10 years. To build the sample, we compare the soft X-ray fluxes of AGNs measured in ROSAT All-Sky Survey (RASS) during 1990-1991 with those measured by XMM-Newton during 2000-2009. This investigation bings forth to a sample of 13 AGNs, which appeared bright in RASS era, and went into low states (flux dropped by a factor of ≳ 10) when they were caught by XMM-Newton. Most of the 13 sources are type I Seyfert galaxies. 5 of them are noticed to have strong X-ray variation for the first time. We study the nature of their variations through performing XMM-Newton spectral analyses and by collecting reports from the existing literature. We find the sample could be divided into three categories according to the possible causes of the strong X-ray variations. The variations in MRK 0478 and 1H 0419-557 are consistent with strong light-bending effect, i.e., the observed X-ray flux drops significantly as the X-ray emitting corona gets much closer to the central black hole. The variations in ESO 140-G043 and NGC 7158 are caused by absorption changes along the line of sight. For one special case MRK 0335, the variation can be explained by either light-bending or absorption variation. In the rest 8 sources (˜ 60%), the strong soft X-ray variations are likely to exist due to intrinsic changes in the activities of the corona, although in some of them without high quality X-ray spectra we are unable to rule out alternative models. This sample provides good targets for future monitoring campaigns with more extensive studies.

  7. GROUND WATER SAMPLING FOR VOCS

    EPA Science Inventory

    Sampling protocol should be dictated by the sampling objective(s). It is important to obtain representative ground water samples, regardless of the sampling objective(s). Low-flow (minimum draw-down) purging and sampling techniques are best in most instances, particularly for VOC...

  8. Fluid sampling tool

    DOEpatents

    Johnston, Roger G.; Garcia, Anthony R. E.; Martinez, Ronald K.

    2001-09-25

    The invention includes a rotatable tool for collecting fluid through the wall of a container. The tool includes a fluid collection section with a cylindrical shank having an end portion for drilling a hole in the container wall when the tool is rotated, and a threaded portion for tapping the hole in the container wall. A passageway in the shank in communication with at least one radial inlet hole in the drilling end and an opening at the end of the shank is adapted to receive fluid from the container. The tool also includes a cylindrical chamber affixed to the end of the shank opposite to the drilling portion thereof for receiving and storing fluid passing through the passageway. The tool also includes a flexible, deformable gasket that provides a fluid-tight chamber to confine kerf generated during the drilling and tapping of the hole. The invention also includes a fluid extractor section for extracting fluid samples from the fluid collecting section.

  9. Global atmospheric sampling program

    NASA Technical Reports Server (NTRS)

    Lezberg, E. A.; Perkins, P. J.; Englund, D. R.; Gauntner, D. J.; Holdeman, J. D.

    1977-01-01

    Automated instruments were installed on a commercial B-747 aircraft, during the program, to obtain baseline data and to monitor key atmospheric constituents associated with emissions of aircraft engines in order to determine if aircraft are contributing to pollution of the upper atmosphere. Data thus acquired on a global basis over the commercial air routes for 5 to 10 years will be analyzed. Ozone measurements in the 29,000 to 45,000 foot altitude were expanded over what has been available from ozonesondes. Limited aerosol composition measurements from filter samples show low levels of sulfates and nitrates in the upper troposphere. Recently installed instruments for measurement of carbon monoxide and condensation nuclei are beginning to return data.

  10. Automated Factor Slice Sampling

    PubMed Central

    Tibbits, Matthew M.; Groendyke, Chris; Haran, Murali; Liechty, John C.

    2013-01-01

    Markov chain Monte Carlo (MCMC) algorithms offer a very general approach for sampling from arbitrary distributions. However, designing and tuning MCMC algorithms for each new distribution, can be challenging and time consuming. It is particularly difficult to create an efficient sampler when there is strong dependence among the variables in a multivariate distribution. We describe a two-pronged approach for constructing efficient, automated MCMC algorithms: (1) we propose the “factor slice sampler”, a generalization of the univariate slice sampler where we treat the selection of a coordinate basis (factors) as an additional tuning parameter, and (2) we develop an approach for automatically selecting tuning parameters in order to construct an efficient factor slice sampler. In addition to automating the factor slice sampler, our tuning approach also applies to the standard univariate slice samplers. We demonstrate the efficiency and general applicability of our automated MCMC algorithm with a number of illustrative examples. PMID:24955002

  11. Revisiting sample entropy analysis

    NASA Astrophysics Data System (ADS)

    Govindan, R. B.; Wilson, J. D.; Eswaran, H.; Lowery, C. L.; Preißl, H.

    2007-03-01

    We modify the definition of sample entropy (SaEn) by incorporating a time delay between the components of the block (from which the densities are estimated) and show that the modified method characterizes the complexity of the system better than the original version. We apply the modified SaEn to the standard deterministic systems and stochastic processes (uncorrelated and long range correlated (LRC) processes) and show that the underlying complexity of the system is better quantified by the modified method. We extend this analysis to the RR intervals of the normal and congestive heart failure (CHF) subjects (available via www.physionet.org) and show that there is a good degree of separation between the two groups.

  12. Sample introducing apparatus and sample modules for mass spectrometer

    DOEpatents

    Thompson, C.V.; Wise, M.B.

    1993-12-21

    An apparatus for introducing gaseous samples from a wide range of environmental matrices into a mass spectrometer for analysis of the samples is described. Several sample preparing modules including a real-time air monitoring module, a soil/liquid purge module, and a thermal desorption module are individually and rapidly attachable to the sample introducing apparatus for supplying gaseous samples to the mass spectrometer. The sample-introducing apparatus uses a capillary column for conveying the gaseous samples into the mass spectrometer and is provided with an open/split interface in communication with the capillary and a sample archiving port through which at least about 90 percent of the gaseous sample in a mixture with an inert gas that was introduced into the sample introducing apparatus is separated from a minor portion of the mixture entering the capillary discharged from the sample introducing apparatus. 5 figures.

  13. Sample introducing apparatus and sample modules for mass spectrometer

    DOEpatents

    Thompson, Cyril V.; Wise, Marcus B.

    1993-01-01

    An apparatus for introducing gaseous samples from a wide range of environmental matrices into a mass spectrometer for analysis of the samples is described. Several sample preparing modules including a real-time air monitoring module, a soil/liquid purge module, and a thermal desorption module are individually and rapidly attachable to the sample introducing apparatus for supplying gaseous samples to the mass spectrometer. The sample-introducing apparatus uses a capillary column for conveying the gaseous samples into the mass spectrometer and is provided with an open/split interface in communication with the capillary and a sample archiving port through which at least about 90 percent of the gaseous sample in a mixture with an inert gas that was introduced into the sample introducing apparatus is separated from a minor portion of the mixture entering the capillary discharged from the sample introducing apparatus.

  14. NEO Sample Return mission

    NASA Astrophysics Data System (ADS)

    Barucci, M. A.; Neo-Sr Team

    The NEOs are representative of the population of asteroids and dead comets thought to be the remnants of the ancient planetesimals that accreted to form the planets. The chemical investigation of NEOs having primitive characteristics is thus essential in the understanding the planet formation and evolution. They carry records of the solar system's birth/early phases and the geological evolution of small bodies in the interplanetary regions. Moreover, collisions of NEOs with Earth represent a serious hazard to life. For all these reasons the exploration and characterization of these objects are particularly interesting and urgent. NEOs are interesting and highly accessible targets for scientific research and robotic exploration. Within this framework, the mission LEONARD including an orbiter and a lander to the primitive double object (1996 FG3) has been studied by CNES, in collaboration with a number of European planetologists (France, Italy, Germany and United Kingdom) and related Space Agencies. A new Sample Return mission is under study within a large European community and possible collaboration with the Japanese Space Agency JAXA to reply to the ESA Cosmic Vision AO. The principal objectives are to investigate on 1) the properties of the building blocks of the terrestrial planets; 2) the major events (e.g. agglomeration, heating, ... . . ) which ruled the history of planetesimals; 3) the primitive asteroids which could contain presolar material unknown in meteoritic samples; 4) the organics in primitive materials; 5) the initial conditions and evolution history of the solar nebula; and 6) how they can shed light on the origin of molecules necessary for life. This type of mission appears clearly to have the potential to revolutionize our understanding of primitive materials.

  15. Soil sampling kit and a method of sampling therewith

    DOEpatents

    Thompson, C.V.

    1991-02-05

    A soil sampling device and a sample containment device for containing a soil sample is disclosed. In addition, a method for taking a soil sample using the soil sampling device and soil sample containment device to minimize the loss of any volatile organic compounds contained in the soil sample prior to analysis is disclosed. The soil sampling device comprises two close fitting, longitudinal tubular members of suitable length, the inner tube having the outward end closed. With the inner closed tube withdrawn a selected distance, the outer tube can be inserted into the ground or other similar soft material to withdraw a sample of material for examination. The inner closed end tube controls the volume of the sample taken and also serves to eject the sample. The soil sample containment device has a sealing member which is adapted to attach to an analytical apparatus which analyzes the volatile organic compounds contained in the sample. The soil sampling device in combination with the soil sample containment device allows an operator to obtain a soil sample containing volatile organic compounds and minimizing the loss of the volatile organic compounds prior to analysis of the soil sample for the volatile organic compounds. 11 figures.

  16. Soil sampling kit and a method of sampling therewith

    DOEpatents

    Thompson, Cyril V.

    1991-01-01

    A soil sampling device and a sample containment device for containing a soil sample is disclosed. In addition, a method for taking a soil sample using the soil sampling device and soil sample containment device to minimize the loss of any volatile organic compounds contained in the soil sample prior to analysis is disclosed. The soil sampling device comprises two close fitting, longitudinal tubular members of suitable length, the inner tube having the outward end closed. With the inner closed tube withdrawn a selected distance, the outer tube can be inserted into the ground or other similar soft material to withdraw a sample of material for examination. The inner closed end tube controls the volume of the sample taken and also serves to eject the sample. The soil sample containment device has a sealing member which is adapted to attach to an analytical apparatus which analyzes the volatile organic compounds contained in the sample. The soil sampling device in combination with the soil sample containment device allow an operator to obtain a soil sample containing volatile organic compounds and minimizing the loss of the volatile organic compounds prior to analysis of the soil sample for the volatile organic compounds.

  17. Fluid sampling apparatus and method

    DOEpatents

    Yeamans, David R.

    1998-01-01

    Incorporation of a bellows in a sampling syringe eliminates ingress of contaminants, permits replication of amounts and compression of multiple sample injections, and enables remote sampling for off-site analysis.

  18. Fluid sampling apparatus and method

    DOEpatents

    Yeamans, D.R.

    1998-02-03

    Incorporation of a bellows in a sampling syringe eliminates ingress of contaminants, permits replication of amounts and compression of multiple sample injections, and enables remote sampling for off-site analysis. 3 figs.

  19. COMPOSITE SAMPLING FOR ENVIRONMENTAL MONITORING

    EPA Science Inventory

    Guidance for selecting a plan to tomposite environmental or biological samples is provided in the form of models, equations, tables, and criteria. Composite sampling procedures can increase sensitivity, reduce sampling variance, and dramatically reduce analytical costs, depending...

  20. Sample Manipulation System for Sample Analysis at Mars

    NASA Technical Reports Server (NTRS)

    Mumm, Erik; Kennedy, Tom; Carlson, Lee; Roberts, Dustyn

    2008-01-01

    The Sample Analysis at Mars (SAM) instrument will analyze Martian samples collected by the Mars Science Laboratory Rover with a suite of spectrometers. This paper discusses the driving requirements, design, and lessons learned in the development of the Sample Manipulation System (SMS) within SAM. The SMS stores and manipulates 74 sample cups to be used for solid sample pyrolysis experiments. Focus is given to the unique mechanism architecture developed to deliver a high packing density of sample cups in a reliable, fault tolerant manner while minimizing system mass and control complexity. Lessons learned are presented on contamination control, launch restraint mechanisms for fragile sample cups, and mechanism test data.