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Sample records for broad iron line

  1. Broad iron lines in Active Galactic Nuclei

    CERN Document Server

    Fabian, A C; Reynolds, C S; Young, A J

    2000-01-01

    An intrinsically narrow line emitted by an accretion disk around a black hole appears broadened and skewed as a result of the Doppler effect and gravitational redshift. The fluorescent iron line in the X-ray band at 6.4-6.9keV is the strongest such line and is seen in the X-ray spectrum of many active galactic nuclei and, in particular, Seyfert galaxies. It is an important diagnostic with which to study the geometry and other properties of the accretion flow very close to the central black hole. The broad iron line indicates the presence of a standard thin accretion disk in those objects, often seen at low inclination. The broad iron line has opened up strong gravitational effects around black holes to observational study with wide-reaching consequences for both astrophysics and physics.

  2. On the apparent absence of broad iron lines in Seyfert galaxies

    OpenAIRE

    Bhayani, Shyam; Nandra, Kirpal

    2011-01-01

    We present an analysis of XMM-Newton observations of eleven Seyfert galaxies that appear to be missing a broad iron K alpha line. These objects represent a challenge to the established paradigm for active galactic nuclei, where a relatively cold accretion disc feeds the central black hole. In that paradigm, X-ray illumination of the accretion disc should lead to continuum and fluorescence emission from iron which is broadened and shifted by relativistic effects close the hole. We extend the w...

  3. Unveiling the broad band X-ray continuum and iron line complex in Mkr 841

    CERN Document Server

    Petrucci, P O; Matt, G; Longinotti, A L; Malzac, J; Mouchet, M; Boisson, C; Maraschi, L; Nandra, K; Ferrando, P

    2007-01-01

    Mkr 841 is a bright Seyfert 1 galaxy known to harbor a strong soft excess and a variable K$\\alpha$ iron line. It has been observed during 3 different periods by XMM for a total cumulated exposure time of $\\sim$108 ks. We present in this paper a broad band spectral analysis of the complete EPIC-pn data sets. We were able to test two different models for the soft excess, a relativistically blurred photoionized reflection (\\r model) and a relativistically smeared ionized absorption (\\a model). The continuum is modeled by a simple cut-off power law and we also add a neutral reflection. These observations reveal the extreme and puzzling spectral and temporal behaviors of the soft excess and iron line. The 0.5-3 keV soft X-ray flux decreases by a factor 3 between 2001 and 2005 and the line shape appears to be a mixture of broad and narrow components. We succeed in describing this complex broad-band 0.5-10 keV spectral variability using either \\r or \\a to fit the soft excess. Both models give statistically equivalen...

  4. Broad line emission from iron K- and L-shell transitions in the active galaxy 1H 0707-495.

    Science.gov (United States)

    Fabian, A C; Zoghbi, A; Ross, R R; Uttley, P; Gallo, L C; Brandt, W N; Blustin, A J; Boller, T; Caballero-Garcia, M D; Larsson, J; Miller, J M; Miniutti, G; Ponti, G; Reis, R C; Reynolds, C S; Tanaka, Y; Young, A J

    2009-05-28

    Since the 1995 discovery of the broad iron K-line emission from the Seyfert galaxy MCG-6-30-15 (ref. 1), broad iron K lines have been found in emission from several other Seyfert galaxies, from accreting stellar-mass black holes and even from accreting neutron stars. The iron K line is prominent in the reflection spectrum created by the hard-X-ray continuum irradiating dense accreting matter. Relativistic distortion of the line makes it sensitive to the strong gravity and spin of the black hole. The accompanying iron L-line emission should be detectable when the iron abundance is high. Here we report the presence of both iron K and iron L emission in the spectrum of the narrow-line Seyfert 1 galaxy 1H 0707-495. The bright iron L emission has enabled us to detect a reverberation lag of about 30 s between the direct X-ray continuum and its reflection from matter falling into the black hole. The observed reverberation timescale is comparable to the light-crossing time of the innermost radii around a supermassive black hole. The combination of spectral and timing data on 1H 0707-495 provides strong evidence that we are witnessing emission from matter within a gravitational radius, or a fraction of a light minute, from the event horizon of a rapidly spinning, massive black hole. PMID:19478778

  5. Origin of the Broad Iron Line Feature and the Soft X-ray Variation in Seyfert Galaxies

    CERN Document Server

    Iso, Naoki; Sameshima, Hiroaki; Mizumoto, Misaki; Miyakawa, Takehiro; Inoue, Hajime; Yamasaki, Hiroki

    2016-01-01

    Many Seyfert galaxies are known to exhibit significant X-ray spectral variations and seemingly broad iron K-emission line features. In this paper, we show that the "variable partial covering model", which has been successfully proposed for MCG-6.30-15 (Miyakawa, Ebisawa & Inoue 2012) and 1H0707.495 (Mizumoto, Ebisawa & Sameshima 2014), can also explain the spectral variations in 2-10 keV as well as the broad iron line features in 20 other Seyfert galaxies observed with Suzaku. In this model, the absorbed spectral component through the optically-thick absorbing clouds has a significant iron K-edge, which primarily accounts for the observed seemingly broad iron line feature. Fluctuation of the absorbing clouds in the line of sight of the extended X-ray source results in variation of the partial covering fraction, which causes an anti-correlation between the direct (not covered) spectral component and the absorbed (covered) spectral component below ~10 keV. Observed spectral variation in 2-10 keV in a ti...

  6. Broad iron emission lines in Seyfert Galaxies - re-condensation of gas onto an inner disk below the ADAF

    OpenAIRE

    Meyer-Hofmeister, E.; Meyer, F

    2011-01-01

    Recent observations of Seyfert 1 AGN with Chandra, XMM-Newton and Suzaku revealed broad iron K_alpha emission lines, some relativistically blurred. For galactic black hole X-ray binaries XMM-Newton spectra during hard state also reveal the presence of a relativistic iron emission line and a thermal component, interpreted as an indication for a weak inner cool accretion disk underneath a hot corona. These thermal components were found after the transition from soft to hard spectral state and c...

  7. Discovery and Monitoring of a Broad Iron Line Complex in GRO J1655-40 by RXTE

    International Nuclear Information System (INIS)

    We present results from detailed spectral analyses of 43 RXTE observations of GRO J1655-40 made throughout 1996. Spectra taken over 27 days separated by about one week each allow us to determine 3-200 keV continuum and line variability during the thermally dominated and steep power-law states seen. Inferred effective radii for maximum disk emission are consistently below 6 gravitational radii, confirming the Kerr nature of the black hole. The broad iron line is modeled by a broad emission line and an absorption edge at ∼6.7 keV. We discuss the variation in line and continuum parameters, and suggest the inner portion of the accretion disk is warped and hot

  8. Constraints on Black Hole Spin in a Sample of Broad Iron Line AGN

    Science.gov (United States)

    Brenneman, Laura W.; Reynolds, Christopher S.

    2008-01-01

    We present a uniform X-ray spectral analysis of nine type-1 active galactic nuclei (AGN) that have been previously found to harbor relativistically broadened iron emission lines. We show that the need for relativistic effects in the spectrum is robust even when one includes continuum "reflection" from the accretion disk. We then proceed to model these relativistic effects in order to constrain the spin of the supermassive black holes in these AGN. Our principal assumption, supported by recent simulations of geometrically-thin accretion disks, is that no iron line emission (or any associated Xray reflection features) can originate from the disk within the innermost stable circular orbit. Under this assumption, which tends to lead to constraints in the form of lower limits on the spin parameter, we obtain non-trivial spin constraints on five AGN. The spin parameters of these sources range from moderate (a approximates 0.6) to high (a > 0.96). Our results allow, for the first time, an observational constraint on the spin distribution function of local supermassive black holes. Parameterizing this as a power-law in dimensionless spin parameter (f(a) varies as absolute value of (a) exp zeta), we present the probability distribution for zeta implied by our results. Our results suggest 90% and 95% confidence limits of zeta > -0.09 and zeta > -0.3 respectively.

  9. On the inability of Comptonization to produce the broad X-ray iron lines observed in Seyfert nuclei

    CERN Document Server

    Reynolds, C S

    1999-01-01

    It has recently been suggested that Compton downscattering may give rise to the broad iron lines seen in the X-ray spectra of Seyfert 1 galaxies. This challenges the standard model in which these lines originate from the innermost regions of the black hole accretion disk with Doppler shifts and gravitational redshifts giving rise to the broadened line profile. Here, we apply observational constraints to the Compton downscattering model for MCG-6-30-15 and NGC3516, the two best cases to date of Seyfert galaxies with relativistically broad lines. We show that the continuum source in MCG-6-30-15 required by the constrained model violates the black body limit. In the case of NGC3516, only a very small region of parameter space is compatible with the constraints. Hence, we conclude that the Comptonization model is not a viable one for the broad line seen in these two objects. The accretion disk model remains the best interpretation of these data.

  10. Broadband X-ray emission and the reality of the broad iron line from the Neutron Star - White Dwarf X-ray binary 4U 1820-30

    CERN Document Server

    Mondal, Aditya S; Pahari, Mayukh; Misra, Ranjeev; Kembhavi, Ajit K; Raychaudhuri, Biplab

    2016-01-01

    Broad relativistic iron lines from neutron star X-ray binaries are important probes of the inner accretion disk. The X-ray reflection features can be weakened due to strong magnetic fields or very low iron abundances such as is possible in X-ray binaries with low mass, first generation stars as companions. Here we investigate the reality of the broad iron line detected earlier from the neutron star low mass X-ray binary 4U~1820--30 with a degenerate helium dwarf companion. We perform a comprehensive, systematic broadband spectral study of the atoll source using \\suzaku{} and simultaneous \

  11. On the reality of broad iron L lines from the narrow line Seyfert 1 galaxies 1H0707-495 and IRAS 13224-3809

    CERN Document Server

    Pawar, Pramod; Patil, Madhav; Misra, Ranjeev; Jogadand, Sharada

    2016-01-01

    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 has been interpreted as relativistically broad Fe L$\\alpha$ lines. Such features are not clearly observed in other AGN despite sometimes having high iron abundance required by the best fitted blurred reflection models. Given the importance of these lines, we explore the possibility if 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 it into segments with typical exposure of few ks. We extracted spectra from each such segment and modelled using a two component phenomenological model consisting of a power law to represent hard component and a black body to represent...

  12. On the Origin of Broad Iron Lines in Neutron Star Low-mass X-ray Binaries

    CERN Document Server

    Chiang, Chia-Ying; Miller, Jon M; Barret, Didier; Fabian, Andy C; D'Ai, Antonino; Parker, Michael L; Bhattacharyya, Sudip; Burderi, Luciano; Di Salvo, Tiziana; Egron, Elise; Homan, Jeroen; Iaria, Rosario; Lin, Dacheng; Miller, M Coleman

    2015-01-01

    Broad Fe K emission lines have been widely observed in the X-ray spectra of black hole systems, and in neutron star systems as well. The intrinsically narrow Fe K fluorescent line is generally believed to be part of the reflection spectrum originating in an illuminated accretion disk, and broadened by strong relativistic effects. However, the nature of the lines in neutron star LMXBs has been under debate. We therefore obtained the longest, high-resolution X-ray spectrum of a neutron star LMXB to date with a 300 ks Chandra HETGS observation of Serpens X-1. The observation was taken under the "continuous clocking" mode and thus free of photon pile-up effects. We carry out a systematic analysis and find that the blurred reflection model fits the Fe line of Serpens X-1 significantly better than a broad Gaussian component does, implying that the relativistic reflection scenario is much preferred. Chandra HETGS also provides highest spectral resolution view of the Fe K region and we find no strong evidence for add...

  13. Revealing the broad iron Kalpha line in Cygnus X-1 through simultaneous XMM-Newton, RXTE, and INTEGRAL observations

    CERN Document Server

    Duro, Refiz; Grinberg, Victoria; Miškovičová, Ivica; Rodriguez, Jérôme; Tomsick, John; Hanke, Manfred; Pottschmidt, Katja; Nowak, Michael A; Kreykenbohm, Sonja; Bel, Marion Cadolle; Bodaghee, Arash; Lohfink, Anne; Kendziorra, Eckhard; Kirsch, Marcus G F; Staubert, Rüdiger; Wilms, Jörn

    2016-01-01

    We report on the analysis of the broad Fe Kalpha line feature of Cygnus X-1 in the spectra of four simultaneous hard intermediate state observations made with the X-ray Multiple Mirror mission (XMM-Newton), the Rossi X-ray Timing Explorer (RXTE), and the International Gamma-Ray Astrophysics Laboratory (INTEGRAL). The high quality of the XMM-Newton data taken in the Modified Timing Mode of the EPIC-pn camera provides a great opportunity to investigate the broadened Fe Kalpha reflection line at 6.4keV with a very high signal to noise ratio. The 4-500keV energy range is used to constrain the underlying continuum and the reflection at higher energies. We first investigate the data by applying a phenomenological model that consists of the sum of an exponentially cutoff power law and relativistically smeared reflection. Additionally, we apply a more physical approach and model the irradiation of the accretion disk directly from the lamp post geometry. All four observations show consistent values for the black hole ...

  14. Revealing the broad ironline in Cygnus X-1 through simultaneous XMM-Newton, RXTE, and INTEGRAL observations

    Science.gov (United States)

    Duro, Refiz; Dauser, Thomas; Grinberg, Victoria; Miškovičová, Ivica; Rodriguez, Jérôme; Tomsick, John; Hanke, Manfred; Pottschmidt, Katja; Nowak, Michael A.; Kreykenbohm, Sonja; Cadolle Bel, Marion; Bodaghee, Arash; Lohfink, Anne; Reynolds, Christopher S.; Kendziorra, Eckhard; Kirsch, Marcus G. F.; Staubert, Rüdiger; Wilms, Jörn

    2016-05-01

    We report on the analysis of the broad Fe Kα line feature of Cyg X-1 in the spectra of four simultaneous hard intermediate state observations made with the X-ray Multiple Mirror mission (XMM-Newton), the Rossi X-ray Timing Explorer (RXTE), and the International Gamma-Ray Astrophysics Laboratory (INTEGRAL). The high quality of the XMM-Newton data taken in the Modified Timing Mode of the EPIC-pn camera provides a great opportunity to investigate the broadened Fe Kα reflection line at 6.4 keV with a very high signal to noise ratio. The 4-500 keV energy range is used to constrain the underlying continuum and the reflection at higher energies. We first investigate the data by applying a phenomenological model that consists of the sum of an exponentially cutoff power law and relativistically smeared reflection. Additionally, we apply a more physical approach and model the irradiation of the accretion disk directly from the lamp post geometry. All four observations show consistent values for the black hole parameters with a spin of a ~ 0.9, in agreement with recent measurements from reflection and disk continuum fitting. The inclination is found to be i ~ 30°, consistent with the orbital inclination and different from inclination measurements made during the soft state, which show a higher inclination. We speculate that the difference between the inclination measurements is due to changes in the inner region of the accretion disk.

  15. Broad-band X-ray emission and the reality of the broad iron line from the neutron star-white dwarf X-ray binary 4U 1820-30

    Science.gov (United States)

    Mondal, Aditya S.; Dewangan, G. C.; Pahari, M.; Misra, R.; Kembhavi, A. K.; Raychaudhuri, B.

    2016-09-01

    Broad relativistic iron lines from neutron star X-ray binaries are important probes of the inner accretion disc. The X-ray reflection features can be weakened due to strong magnetic fields or very low iron abundances such as is possible in X-ray binaries with low mass, first generation stars as companions. Here, we investigate the reality of the broad iron line detected earlier from the neutron-star low-mass X-ray binary 4U 1820-30 with a degenerate helium dwarf companion. We perform a comprehensive, systematic broad-band spectral study of the atoll source using Suzaku and simultaneous NuSTAR and Swift observations. We have used different continuum models involving accretion disc emission, thermal blackbody and thermal Comptonization of either disc or blackbody photons. The Suzaku data show positive and negative residuals in the region of Fe K band. These features are well described by two absorption edges at 7.67 ± 0.14 keV and 6.93 ± 0.07 keV or partial covering photoionized absorption or by blurred reflection. Though, the simultaneous Swift and NuSTAR data do not clearly reveal the emission or absorption features, the data are consistent with the presence of either absorption or emission features. Thus, the absorption based models provide an alternative to the broad iron line or reflection model. The absorption features may arise in winds from the inner accretion disc. The broad-band spectra appear to disfavour continuum models in which the blackbody emission from the neutron-star surface provides the seed photons for thermal Comptonization. Our results suggest emission from a thin accretion disc (kTdisc ˜ 1 keV), Comptonization of disc photons in a boundary layer most likely covering a large fraction of the neutron-star surface and innermost parts of the accretion disc, and blackbody emission (kTbb ˜ 2 keV) from the polar regions.

  16. Relativistic redshifts in quasar broad lines

    CERN Document Server

    Tremaine, Scott; Liu, Xin; Loeb, Abraham

    2014-01-01

    The broad emission lines commonly seen in quasar spectra have velocity widths of a few per cent of the speed of light, so special- and general-relativistic effects have a significant influence on the line profile. We have determined the redshift of the broad H-beta line in the quasar rest frame (determined from the core component of the [OIII] line) for over 20,000 quasars from the Sloan Digital Sky Survey DR7 quasar catalog. The mean redshift as a function of line width is approximately consistent with the relativistic redshift that is expected if the line originates in a randomly oriented Keplerian disk that is obscured when the inclination of the disk to the line of sight exceeds ~30-45 degrees, consistent with simple AGN unification schemes. This result also implies that the net line-of-sight inflow/outflow velocities in the broad-line region are much less than the Keplerian velocity when averaged over a large sample of quasars with a given line width.

  17. The broad iron Kalpha line of Cygnus X-1 as seen by XMM-Newton in the EPIC-pn modified timing mode

    CERN Document Server

    Duro, R; Wilms, J; Pottschmidt, K; Nowak, M A; Fritz, S; Kendziorra, E; Kirsch, M G F; Reynolds, C S; Staubert, R

    2011-01-01

    We present the analysis of the broadened, flourescent iron Kalpha line in simultaneous XMM-Newton and RXTE data from the black hole Cygnus X-1. The XMM-Newton data were taken in a modified version of the timing mode of the EPIC-pn camera. In this mode the lower energy threshold of the instrument is increased to 2.8 keV to avoid telemetry drop outs due to the brightness of the source, while at the same time preserving the signal-to-noise ratio in the Fe Kalpha band. We find that the best-fit spectrum consists of the sum of an exponentially cut off power-law and relativistically smeared, ionized reflection. The shape of the broadened Fe Kalpha feature is due to strong Compton broadening combined with relativistic broadening. Assuming a standard, thin accretion disk, the black hole is close to rotating maximally.

  18. Giant Broad Line Regions in Dwarf Seyferts

    CERN Document Server

    Devereux, Nick

    2015-01-01

    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, ...

  19. The Broad Iron K-alpha line of Cygnus X-1 as Seen by XMM-Newton in the EPIC-pn Modified Timing Mode

    Science.gov (United States)

    Duro, Refiz; Dauser, Thomas; Wilms, Jorn; Pottschmidt, Katja; Nowak, Michael A.; Fritz, Sonja; Kendziorra, Eckhard; Kirsch, Marcus G. F.; Reynolds, Christopher S.; Staubert, Rudiger

    2011-01-01

    We present the analysis of the broadened, flourescent iron K(alpha) line in simultaneous XMM-Newton and RXTE data from the black hole Cygnus X-I. The XMM-Newton data were taken in a modified version of the Timing Mode of the EPIC-pn camera. In this mode the lower energy threshold of the instrument is increased to 2.8 keV to avoid telemetry drop outs due to the brightness of the source, while at the same time preserving the signal to noise ratio in the Fe K(alpha) band. We find that the best-fit spectrum consists of the sum of an exponentially cut-off power-law and relativistically smeared, ionized reflection. The shape of the broadened Fe K(alpha) feature is due to strong Compton broadening combined with relativistic broadening. Assuming a standard, thin accretion disk, the black hole is close to maximally rotating. Key words. X-rays: binaries - black hole physics - gravitation

  20. Broad line regions in Seyfert-1 galaxies

    International Nuclear Information System (INIS)

    To reproduce observed emission profiles of Seyfert galaxies, rotation in an accretion disk has been proposed. In this thesis, the profiles emitted by such an accretion disk are investigated. Detailed comparison with the observed profiles yields that a considerable fraction can be fitted with a power-law function, as predicted by the model. The author analyzes a series of high quality spectra of Seyfert galaxies, obtained with the 2.5m telescope at Las Campanas. He presents detailed analyses of two objects: Mkn335 and Akn120. In both cases, strong evidence is presented for the presence of two separate broad line zones. These zones are identified with an accretion disk and an outflowing wind. The disk contains gas with very high densities and emits predominantly the lower ionization lines. He reports on the discovery of very broad wings beneath the strong forbidden line 5007. (Auth.)

  1. Photoionisation modelling of the broad line region

    Science.gov (United States)

    King, Anthea

    2016-08-01

    Two of the most fundamental questions regarding the broad line region (BLR) are "what is its structure?" and "how is it moving?" Baldwin et al. (1995) showed that by summing over an ensemble of clouds at differing densities and distances from the ionising source we can easily and naturally produce a spectrum similar to what is observed for AGN. This approach is called the `locally optimally emitting clouds' (LOC) model. This approach can also explain the well-observed stratification of emission lines in the BLR (e.g. Clavel et al. 1991, Peterson et al. 1991, Kollatschny et al. 2001) and `breathing' of BLR with changes in the continuum luminosity (Netzer & Mor 1990, Peterson et al. 2014) and is therefore a generally accepted model of the BLR. However, LOC predictions require some assumptions to be made about the distribution of the clouds within the BLR. By comparing photoionization predictions, for a distribution of cloud properties, with observed spectra we can infer something about the structure of the BLR and distribution of clouds. I use existing reverberation mapping data to constrain the structure of the BLR by observing how individual line strengths and ratios of different lines change in high and low luminosity states. I will present my initial constraints and discuss the challenges associated with the method.

  2. Magnetohydrodynamic stability of broad line region clouds

    CERN Document Server

    Krause, Martin; Burkert, Andreas

    2012-01-01

    Hydrodynamic stability has been a longstanding issue for the cloud model of the broad line region in active galactic nuclei. We argue that the clouds may be gravitationally bound to the supermassive black hole. If true, stabilisation by thermal pressure alone becomes even more difficult. We further argue that if magnetic fields should be present in such clouds at a level that could affect the stability properties, they need to be strong enough to compete with the radiation pressure on the cloud. This would imply magnetic field values of a few Gauss for a sample of Active Galactic Nuclei we draw from the literature. We then investigate the effect of several magnetic configurations on cloud stability in axi-symmetric magnetohydrodynamic simulations. For a purely azimuthal magnetic field which provides the dominant pressure support, the cloud first gets compressed by the opposing radiative and gravitational forces. The pressure inside the cloud then increases, and it expands vertically. Kelvin-Helmholtz and colu...

  3. Peculiar Broad Absorption Line Quasars found in DPOSS

    CERN Document Server

    Brunner, R J; Djorgovski, S G; Gal, R R; Mahabal, A A; Lopes, P A A; De Carvalho, R R; Odewahn, S C; Castro, S; Thompson, D; Chaffee, F; Darling, J; Desai, V; Brunner, Robert J.; Hall, Patrick B.

    2003-01-01

    With the recent release of large (i.e., > hundred million objects), well-calibrated photometric surveys, such as DPOSS, 2MASS, and SDSS, spectroscopic identification of important targets is no longer a simple issue. In order to enhance the returns from a spectroscopic survey, candidate sources are often preferentially selected to be of interest, such as brown dwarfs or high redshift quasars. This approach, while useful for targeted projects, risks missing new or unusual species. We have, as a result, taken the alternative path of spectroscopically identifying interesting sources with the sole criterion being that they are in low density areas of the g - r and r - i color-space defined by the DPOSS survey. In this paper, we present three peculiar broad absorption line quasars that were discovered during this spectroscopic survey, demonstrating the efficacy of this approach. PSS J0052+2405 is an Iron LoBAL quasar at a redshift z = 2.4512 with very broad absorption from many species. PSS J0141+3334 is a reddened...

  4. Clues to Quasar Broad Line Region Geometry and Kinematics

    DEFF Research Database (Denmark)

    Vestergaard, Marianne; Wilkes, B. J.; Barthel, P. D.

    2000-01-01

    width to show significant inverse correlations with the fractional radio core-flux density, R, the radio axis inclination indicator. Highly inclined systems have broader line wings, consistent with a high-velocity field perpendicular to the radio axis. By contrast, the narrow line-core shows...... and with an accretion disk-wind emitting the broad lines. A spherical distribution of randomly orbiting broad-line clouds and a polar high-ionization outflow are ruled out....

  5. AGN Broad Line Regions Scale with Bolometric Luminosity

    CERN Document Server

    Trippe, Sascha

    2015-01-01

    The masses of supermassive black holes in active galactic nuclei (AGN) can be derived spectroscopically via virial mass estimators based on selected broad optical/ultraviolet emission lines. These estimates commonly use the line width as a proxy for the gas speed and the monochromatic continuum luminosity as a proxy for the radius of the broad line region. However, if the size of the broad line region scales with bolometric rather than monochromatic AGN luminosity, mass estimates based on different emission lines will show a systematic discrepancy which is a function of the color of the AGN continuum. This has actually been observed in mass estimates based on H-alpha / H-beta and C IV lines, indicating that AGN broad line regions indeed scale with bolometric luminosity. Given that this effect seems to have been overlooked as yet, currently used single-epoch mass estimates are likely to be biased.

  6. Broad Iron Emission from Gravitationally Lensed Quasars Observed by Chandra

    CERN Document Server

    Walton, D J; Miller, J M; Reis, R C; Stern, D; Harrison, F A

    2015-01-01

    Recent work has demonstrated the potential of gravitationally lensed quasars to extend measurements of black hole spin out to high-redshift with the current generation of X-ray observatories. Here we present an analysis of a large sample of 27 lensed quasars in the redshift range 1.0iron K emission from these sources. Although the X-ray signal-to-noise (S/N) currently available does not permit the detection of iron emission from the inner accretion disk in individual cases in our sample, we find significant structure in the stacked residuals. In addition to the narrow core, seen almost ubiquitously in local AGN, we find evidence for an additional underlying broad component from the inner accretion disk, with a clear red wing to the emission profile. Based on simulations, we find the detection of this broader component to be significant at greater than the 3-sigma level. This implies that iron emission...

  7. 49 CFR 192.373 - Service lines: Cast iron and ductile iron.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Service lines: Cast iron and ductile iron. 192.373... Regulators, and Service Lines § 192.373 Service lines: Cast iron and ductile iron. (a) Cast or ductile iron... cast iron pipe or ductile iron pipe is installed for use as a service line, the part of the...

  8. X-ray spectroscopy of the broad line radio galaxy 3C111

    CERN Document Server

    Reynolds, C S; Crawford, C S; Fabian, A C

    1998-01-01

    We present an ASCA observation of the broad line radio galaxy 3C111. The X-ray spectrum is well described by a model consisting of a photoelectrically-absorbed power-law form. The inferred absorbing column density is significantly greater than expected on the basis of 21-cm measurements of Galactic HI. Whilst this may be due intrinsic absorption from a circumnuclear torus or highly warped accretion disk, inhomogeneities and molecular gas within the foreground giant molecular cloud may also be responsible for some of this excess absorption. We also claim a marginal detection of a broad iron Ka line which is well explained as being a fluorescent line originating from the central regions of a radiatively-efficient accretion disk. This line appears weak in comparison to those found in (radio-quiet) Seyfert nuclei. We briefly discuss the implications of this fact.

  9. Evidence for Photoionization Driven Broad Absorption Line Variability

    CERN Document Server

    Wang, Tinggui; Wang, Huiyuan; Ferland, Gary

    2015-01-01

    We present a qualitative analysis of the variability of quasar broad absorption lines using the large multi-epoch spectroscopic dataset of the Sloan Digital Sky Survey Data Release 10. We confirm that variations of absorption lines are highly coordinated among different components of the same ion or the same absorption component of different ions for C IV, Si IV and N V. Furthermore, we show that the equivalent widths of the lines decrease or increase statistically when the continuum brightens or dims. This is further supported by the synchronized variations of emission and absorption line equivalent width, when the well established intrinsic Baldwin effect for emission lines is taken into account. We find that the emergence of an absorption component is usually accompanying with dimming of the continuum while the disappearance of an absorption line component with brightening of the continuum. This suggests that the emergence or disappearance of a C IV absorption component is only the extreme case, when the i...

  10. Spectral Decomposition of Broad-Line AGNs and Host Galaxies

    CERN Document Server

    Vanden Berk, Daniel E; Yip, C W; Schneider, D P; Connolly, A J; Burton, R E; Jester, S; Hall, P B; Szalay, A S; Brinkmann, J; Berk, Daniel E. Vanden; Shen, Jiajian; Yip, Ching-Wa; Schneider, Donald P.; Connolly, Andrew J.; Burton, Ross E.; Jester, Sebastian; Hall, Patrick B.; Szalay, Alex S.; Brinkmann, John

    2005-01-01

    Using an eigenspectrum decomposition technique, we separate the host galaxy from the broad line active galactic nucleus (AGN) in a set of 4666 spectra from the Sloan Digital Sky Survey (SDSS), from redshifts near zero up to about 0.75. The decomposition technique uses separate sets of galaxy and quasar eigenspectra to efficiently and reliably separate the AGN and host spectroscopic components. The technique accurately reproduces the host galaxy spectrum, its contributing fraction, and its classification. We show how the accuracy of the decomposition depends upon S/N, host galaxy fraction, and the galaxy class. Based on the eigencoefficients, the sample of SDSS broad-line AGN host galaxies spans a wide range of spectral types, but the distribution differs significantly from inactive galaxies. In particular, post-starburst activity appears to be much more common among AGN host galaxies. The luminosities of the hosts are much higher than expected for normal early-type galaxies, and their colors become increasing...

  11. Virilization of the Broad Line Region in Active Galactic Nuclei - connection between shifts and widths of broad emission lines

    CERN Document Server

    Jonic, Sanja; Ilic, Dragana; Popovic, Luka C

    2016-01-01

    We investigate the virilization of the emission lines Hbeta and Mg II in the sample of 287 Type 1 Active Galactic Nuclei taken from the Sloan Digital Sky Survey database. We explore the connections between the intrinsic line shifts and full widths at different levels of maximal intensity. We found that: (i) Hbeta seems to be a good virial estimator of black hole masses, and an intrinsic redshift of Hbeta is dominantly caused by the gravitational effect, (ii) there is an anti-correlation between the redshift and width of the wings of the Mg II line, (iii) the broad Mg II line can be used as virial estimator only at 50% of the maximal intensity, while the widths and intrinsic shifts of the line wings can not be used for this purpose.

  12. Broad Absorption Line Quasar catalogues with Supervised Neural Networks

    International Nuclear Information System (INIS)

    We have applied a Learning Vector Quantization (LVQ) algorithm to SDSS DR5 quasar spectra in order to create a large catalogue of broad absorption line quasars (BALQSOs). We first discuss the problems with BALQSO catalogues constructed using the conventional balnicity and/or absorption indices (BI and AI), and then describe the supervised LVQ network we have trained to recognise BALQSOs. The resulting BALQSO catalogue should be substantially more robust and complete than BI-or AI-based ones.

  13. The Nature of Partial Covering in Broad Absorption Line Quasars

    Science.gov (United States)

    Leighly, Karen

    2012-10-01

    Ejected gas is seen as broad absorption lines in 20% of quasars. It has been known for 15 years that prominent lines such as CIV are usually saturated but not black because the absorbing gas only partially covers the continuum emission region. Therefore, column densities estimated from these lines are only lower limits. Accurate column densities can be obtained from rare ions that have two or more transitions from the same lower level, so that the optical depth and covering fraction can be solved for simultanously. Suitable lines are hard to find, so such measurements are rare. We have found that metastable helium is particularly useful for these measurements. Yet despite these advances, partial covering remains a just a parameter and its physical nature is not understood.We propose a unique experiment to constrain the physical nature of partial covering. We will compare the covering fraction measured from PV {a doublet in the far UV} with that measured from metastable HeI {optical and IR}. The ions creating these lines are relatively rare, and they present similar opacity over a wide range of gas parameters. But due to their wide wavelength separation, these lines probe dramatically different regions of the continuum source, the temperature-dependent accretion disk. So we expect different covering fraction behavior for different partial covering scenarios. This experiment is relevant for understanding the geometry and clumpiness of the outflow, and the results may impact our understanding of the global covering fraction, a parameter critical for determining the outflow kinetic luminosity, and thereby estimating feedback efficiency for broad absorption line outflows.

  14. Quasar Cartography: from Black Hole to Broad Line Region Scales

    CERN Document Server

    Chelouche, Doron

    2013-01-01

    A generalized approach to reverberation mapping (RM) is presented, which is applicable to broad- and narrow-band photometric data, as well as to spectroscopic observations. It is based on multivariate correlation analysis techniques and, in its present implementation, is able to identify reverberating signals across the accretion disk and the broad line region (BLR) of active galactic nuclei (AGN). Statistical tests are defined to assess the significance of time-delay measurements using this approach, and the limitations of the adopted formalism are discussed. It is shown how additional constraints on some of the parameters of the problem may be incorporated into the analysis thereby leading to improved results. When applied to a sample of 14 Seyfert 1 galaxies having good-quality high-cadence photometric data, accretion disk scales and BLR sizes are simultaneously determined, on a case-by-case basis, in most objects. The BLR scales deduced here are in good agreement with the findings of independent spectrosc...

  15. VLBA imaging of radio-loud Broad Absorption Line QSOs

    CERN Document Server

    Montenegro-Montes, F M; Benn, C R; Carballo, R; Dallacasa, D; González-Serrano, J I; Holt, J; Jiménez-Luján, F

    2009-01-01

    Broad Absorption Line Quasars (BAL QSOs) have been found to be associated with extremely compact radio sources. These reduced dimensions can be either due to projection effects or these objects might actually be intrinsically small. Exploring these two hypotheses is important to understand the nature and origin of the BAL phenomenon because orientation effects are an important discriminant between the different models proposed to explain this phenomenon. In this work we present VLBA observations of 5 BAL QSOs and discuss their pc-scale morphology.

  16. The Broad-lined Type Ic SN 2003jd

    CERN Document Server

    Valenti, S; Cappellaro, E; Patat, F; Mazzali, P; Turatto, M; Hurley, K; Maeda, K; Gal-Yam, A; Foley, R J; Filippenko, A V; Pastorello, A; Challis, P; Frontera, F; Harutyunyan, A; Iye, M; Kawabata, K; Kirshner, R P; Li, W; Lipkin, Y M; Matheson, T; Nomoto, K; Ofek, E O; Ohyama, Y; Pian, E; Salvo, M; Sauer, D N; Schmidt, B P; Soderberg, A; Zampieri, L

    2007-01-01

    The results of a world-wide coordinated observational campaign on the broad-lined Type Ic SN 2003jd are presented. In total, 74 photometric data points and 26 spectra were collected using 11 different telescopes. SN 2003jd is one of the most luminous SN Ic ever observed. A comparison with other Type Ic supernovae (SNe Ic) confirms that SN 2003jd represents an intermediate case between broad-line events (2002ap, 2006aj), and highly energetic SNe (1997ef, 1998bw, 2003dh, 2003lw), with an ejected mass of M_{ej} = 3.0 +/- 1 Mo and a kinetic energy of E_{k}(tot) = 7_{-2}^{+3} 10^{51} erg. SN 2003jd is similar to SN 1998bw in terms of overall luminosity, but it is closer to SNe 2006aj and 2002ap in terms of light-curve shape and spectral evolution. The comparison with other SNe Ic, suggests that the V-band light curves of SNe Ic can be partially homogenized by introducing a time stretch factor. Finally, due to the similarity of SN 2003jd to the SN 2006aj/XRF 060218 event, we discuss the possible connection of SN 20...

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

    Energy Technology Data Exchange (ETDEWEB)

    Vanden Berk, Daniel E.; Shen, Jiajian; /Penn State U., Astron. Astrophys.; Yip, Ching-Wa; /Pittsburgh U.; Schneider, Donald P.; /Penn State U., Astron. Astrophys.; Connolly,; /Pittsburgh U.; Burton, Ross E.; /Pittsburgh U. /Case Western Reserve U.; Jester, Sebastian; /Fermilab; Hall, Patrick B.; /York U., Canada; Szalay, Alex S.; /Johns Hopkins; Brinkmann, John; /Apache Point Observ.

    2005-09-01

    Using an eigenspectrum decomposition technique, we separate the host galaxy from the broad line active galactic nucleus (AGN) in a set of 4666 spectra from the Sloan Digital Sky Survey (SDSS), from redshifts near zero up to about 0.75. The decomposition technique uses separate sets of galaxy and quasar eigenspectra to efficiently and reliably separate the AGN and host spectroscopic components. The technique accurately reproduces the host galaxy spectrum, its contributing fraction, and its classification. We show how the accuracy of the decomposition depends upon S/N, host galaxy fraction, and the galaxy class. Based on the eigencoefficients, the sample of SDSS broad-line AGN host galaxies spans a wide range of spectral types, but the distribution differs significantly from inactive galaxies. In particular, post-starburst activity appears to be much more common among AGN host galaxies. The luminosities of the hosts are much higher than expected for normal early-type galaxies, and their colors become increasingly bluer than early-type galaxies with increasing host luminosity. Most of the AGNs with detected hosts are emitting at between 1% and 10% of their estimated Eddington luminosities, but the sensitivity of the technique usually does not extend to the Eddington limit. There are mild correlations among the AGN and host galaxy eigencoefficients, possibly indicating a link between recent star formation and the onset of AGN activity. The catalog of spectral reconstruction parameters is available as an electronic table.

  18. The Iron Abundance of IOTA Herculis From Ultraviolet Iron Lines

    Science.gov (United States)

    Grigsby, J.; Mulliss, C.; Baer, G.

    1995-03-01

    We have obtained (Adelman 1992, 1993, private comunication) coadded, high-resolution IUE spectra of Iota Herculis (B3 IV) in both short wavelength (SWP) and long wavelength (LWP) regions. The spectra span the ultraviolet spectrum from 110 - 300 nm and have a SNR of roughly 30 -50; they are described in Adelman et. al. (1993, ApJ 419, 276). Abundance indicators were 54 lines of Fe II and 26 lines of Fe III whose atomic parameters have been measured in the laboratory. LTE synthetic spectra for comparison with observations were produced with the Kurucz model atmosphere and spectral synthesis codes ATLAS9/SYNTHE (Kurucz 1979, ApJS 40,1; Kurucz and Avrett 1981, SAO Special Report 391). Model parameters were chosen from the literature: effective temperature = 17500 K, log g =3.75, v sin i= 11 km/s, and turbulent velocity = 0 km/s. (Peters and Polidan 1985, in IAU Symposium 111, ed. D. S. Hayes et al. (Dordrecht: Reidel), 417). We determined the equivalent widths of the chosen lines by fitting gaussian profiles to the lines and by measuring the equivalent widths of the gaussians. We derived abundances by fitting a straight line to a plot of observed equivalent widths vs. synthetic equivalent widths; we adjusted the iron abundance of the models until a slope of unity was achieved. The abundances derived from the different ionization stages are in agreement: Fe II lines indicate an iron abundance that is 34 +15/-10% the solar value([Fe/H]=-0.47 +0.16-0.15dex), while from Fe III lines we obtain 34 +/- 10% ([Fe/H]=-0.47 +0.11/-0.15 dex). A search of the literature suggests that no previous investigations of this star's iron abundance have found agreement between the different ionization stages. We thank Saul Adelman for his generous assistance, and the Faculty Research Fund Board of Wittenberg University for support of this research.

  19. Iron line reverberation mapping with Constellation-X

    CERN Document Server

    Young, A J

    1999-01-01

    The broad X-ray iron line seen in the spectra of many AGN is thought to originate from the inner regions of the putative black hole accretion disk, and hence provides a rare probe of that central region. In principle, future high throughput X-ray spectrometers should be able to examine the temporal response of this fluorescent line to flares in the X-ray continuum source (which energizes this emission line) - i.e. iron line reverberation mapping will be possible. It has been previously found that there are robust reverberation signatures of the black hole spin, mass and the X-ray flare location above the accretion disk. Here, we simulate observations of a bright Seyfert nucleus with the proposed NASA mission Constellation-X and demonstrate the feasibility of detecting these reverberation signatures with this mission. Hence, starting with XMM in 1999, and maturing with Constellation-X in c2010, iron line reverberation will open a new window on the innermost regions of AGN.

  20. Suzaku Observations of Iron Lines and Reflection in AGN

    CERN Document Server

    Reeves, J N; Kataoka, J; Kunieda, H; Markowitz, A; Miniutti, G; Okajima, T; Serlemitsos, P; Takahashi, T; Terashima, Y; Yaqoob, T

    2006-01-01

    Initial results on the iron K-shell line and reflection component in several AGN observed as part of the Suzaku Guaranteed time program are reviewed. This paper discusses a small sample of Compton-thin Seyferts observed to date with Suzaku; namely MCG -5-23-16, MCG -6-30-15, NGC 4051, NGC 3516, NGC 2110, 3C 120 and NGC 2992. The broad iron K$\\alpha$ emission line appears to be present in all but one of these Seyfert galaxies, while the narrow core of the line from distant matter is ubiquitous in all the observations. The iron line in MCG -6-30-15 shows the most extreme relativistic blurring of all the objects, the red-wing of the line requires the inner accretion disk to extend inwards to within 2.2Rg of the black hole, in agreement with the XMM-Newton observations. Strong excess emission in the Hard X-ray Detector (HXD) above 10 keV is observed in many of these Seyfert galaxies, consistent with the presence of a reflection component from reprocessing in Compton-thick matter (e.g. the accretion disk). Only on...

  1. Radio Structures of Compact Quasars with Broad Absorption Lines

    Science.gov (United States)

    Kunert-Bajraszewska, Magdalena; Gawroński, Marcin P.

    2010-05-01

    Broad absorption lines (BALs), seen in a small fraction of both the radio-quiet and radio-loud quasar populations, are probably caused by the outflow of gas with high velocities and are part of the accretion process. The presence of BALs is due to a geometrical effect and/or it is connected with the quasar evolution. Using the final release of FIRST survey combined with a catalog of BAL QSOs from SDSS/DR3, we have constructed a new sample of compact radio-loud BAL QSOs, which constitutes the majority of radio-loud BAL QSOs. The main goal of this project is to study the origin of BALs by analysis of the BAL QSOs radio morphology, orientation, and jet evolution using the European VLBI Network (EVN) at 1.6 GHz and the Very Long Baseline Array (VLBA) at 5 and 8.4 GHz.

  2. The Broad Line Radio Galaxy J2114+820

    CERN Document Server

    Lara, L; Cotton, W D; Feretti, L; Giovannini, G; Marcaide, J M; Venturi, T

    1998-01-01

    In the frame of the study of a new sample of large angular size radio galaxies selected from the NRAO VLA Sky Survey, we have made radio observations of J2114+820, a low power radio galaxy with an angular size of 6'. Its radio structure basically consists of a prominent core, a jet directed in north-west direction and two extended S-shaped lobes. We have also observed the optical counterpart of J2114+820, a bright elliptical galaxy with a strong unresolved central component. The optical spectrum shows broad emission lines. This fact, together with its low radio power and FR-I type morphology, renders J2114+820 a non-trivial object from the point of view of the current unification schemes of radio loud active galactic nuclei.

  3. SPECTROSCOPY OF BROAD-LINE BLAZARS FROM 1LAC

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, Michael S.; Romani, Roger W.; Healey, Stephen E.; Michelson, Peter F. [Department of Physics/KIPAC, Stanford University, Stanford, CA 94305 (United States); Cotter, Garret; Potter, William J. [Department of Astrophysics, University of Oxford, Oxford OX1 3RH (United Kingdom); Readhead, Anthony C. S.; Richards, Joseph L.; Max-Moerbeck, Walter; King, Oliver G. [Department of Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States)

    2012-03-20

    We report on optical spectroscopy of 165 flat spectrum radio quasars (FSRQs) in the Fermi 1LAC sample, which have helped allow a nearly complete study of this population. Fermi FSRQs show significant evidence for non-thermal emission even in the optical; the degree depends on the {gamma}-ray hardness. They also have smaller virial estimates of hole mass than the optical quasar sample. This appears to be largely due to a preferred (axial) view of the {gamma}-ray FSRQ and non-isotropic (H/R {approx} 0.4) distribution of broad-line velocities. Even after correction for this bias, the Fermi FSRQs show higher mean Eddington ratios than the optical population. A comparison of optical spectral properties with Owens Valley Radio Observatory radio flare activity shows no strong correlation.

  4. Narrow line Seyfert 1 galaxies: where are the broad line regions?

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A sample consisting of 211 narrow line Seyfert 1 galaxies (NLS1s) with high quality spectra from the Sloan Digital Sky Survey (SDSS) is selected to explore where broad line regions are in these objects. We find that the Hβ profile can be fitted well by three (narrow, intermediate and broad) Gaussian components, and the FWHM ratios of the broad to the intermediate components hold a constant of 3.0 roughly for the entire sample. If the broad components originate from the region scaled by the well-determined Hβ reverberation mapping relation, we find that the intermediate components originate from the inner edge of the torus, which is scaled by dust K-band reverberation. We find that the IC and the BC are strongly linked dynamically, but the relation of their covering factors is much more relaxed, implying that both regions are clumpy.

  5. Significant contribution of the Cerenkov line-like radiation to the broad emission lines of quasars

    Energy Technology Data Exchange (ETDEWEB)

    Liu, D. B.; You, J. H. [Institute of Nuclear, Particle, Astronomy and Cosmology, Department of Physics and Astronomy, and Shanghai Key Lab for Particle Physics and Cosmology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); Chen, W. P. [Institute of Astronomy and Department of Physics, National Central University, Chung-Li 32054, Taiwan (China); Chen, L., E-mail: dbliu@sjtu.edu.cn, E-mail: dliu@cfa.Harvard.edu [Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121, Bonn (Germany)

    2014-01-01

    The Cerenkov line-like radiation in a dense gas (N {sub H} > 10{sup 13} cm{sup –3}) is potentially important in the exploration of the optical broad emission lines of quasars and Seyfert 1 galaxies. With this quasi-line emission mechanism, some long standing puzzles in the study of quasars could be resolved. In this paper, we calculate the power of the Cerenkov line-like radiation in dense gas and compare with the powers of other radiation mechanisms by a fast electron to confirm its importance. From the observed gamma-ray luminosity of 3C 279, we show that the total number of fast electrons is sufficiently high to allow effective operation of the quasi-line emission. We present a model calculation for the luminosity of the Cerenkov Lyα line of 3C 279, which is high enough to compare with observations. We therefore conclude that the broad line of quasars may be a blend of the Cerenkov emission line with the real line produced by the bound-bound transition. A new approach to the absorption of the Cerenkov line is presented with the method of escape probability, which markedly simplifies the computation in the optically thick case. The revised set of formulae for the Cerenkov line-like radiation is more convenient in applications.

  6. The Physical Nature of Polar Broad Absorption Line Quasars

    Science.gov (United States)

    Ghost, Kajal; Punsly, Brian

    2007-01-01

    It has been shown based on radio variability arguments that some BALQSOs (broad absorption line quasars) are viewed along the polar axis (o rthogonal to accretion disk) in the recent article of Zhou et a. Thes e arguments are based on the brightness temperature, T(sub b) exceedi ng 10(exp 12) K which leads to the well-known inverse Compton catastr ophe unless the radio jet is relativistic and is viewed along its axi s. In this letter, we expand the Zhou et al sample of polar BALQSOs u sing their techniques applied to SDSS DR5. In the process, we clarify a mistake in their calculation of brightness temperature. The expanded sample of high T(sub b) BALQSOS, has an inordinately large fraction of LoBALQSOs (low ionization BALQSOs). We consider this an important clue to understanding the nature of the polar BALQSOs. This is expec ted in the polar BALQSO analytical/numerical models of Punsly that pr edicted that LoBALQSOs occur when the line of sight is very close to the polar axis, where the outflow density is the highest.

  7. A Variable PV Broad Absorption Line and Quasar Outflow Energetics

    CERN Document Server

    Capellupo, Daniel M; Barlow, Tom A

    2014-01-01

    Broad absorption lines (BALs) in quasar spectra identify high velocity outflows that might exist in all quasars and could play a major role in feedback to galaxy evolution. The viability of BAL outflows as a feedback mechanism depends on their kinetic energies, as derived from the outflow velocities, column densities, and distances from the central quasar. We estimate these quantities for the quasar, Q1413+1143 (redshift $z_e = 2.56$), aided by the first detection of PV $\\lambda\\lambda$1118,1128 BAL variability in a quasar. In particular, PV absorption at velocities where the CIV trough does not reach zero intensity implies that the CIV BAL is saturated and the absorber only partially covers the background continuum source (with characteristic size 22.3 (cm^-2). Variability in the PV and saturated CIV BALs strongly disfavors changes in the ionization as the cause of the BAL variability, but supports models with high-column density BAL clouds moving across our lines of sight. The observed variability time of ...

  8. Clustering Measurements of broad-line AGNs: Review and Future

    CERN Document Server

    Krumpe, Mirko; Coil, Alison L

    2013-01-01

    Despite substantial effort, the precise physical processes that lead to the growth of super-massive black holes in the centers of galaxies are still not well understood. These phases of black hole growth are thought to be of key importance in understanding galaxy evolution. Forthcoming missions such as eROSITA, HETDEX, eBOSS, BigBOSS, LSST, and Pan-STARRS will compile by far the largest ever Active Galactic Nuclei (AGNs) catalogs which will allow us to measure the spatial distribution of AGNs in the universe with unprecedented accuracy. For the first time, AGN clustering measurements will reach a level of precision that will not only allow for an alternative approach to answering open questions in AGN/galaxy co-evolution but will open a new frontier, allowing us to precisely determine cosmological parameters. This paper reviews the large-scale clustering measurements of broad line AGNs. We summarize how clustering is measured and which constraints can be derived from AGN clustering measurements, we discuss re...

  9. Transient C IV Broad Absorption Lines in radio detected QSOs

    CERN Document Server

    Vivek, M; Gupta, N

    2015-01-01

    We study the transient (i.e. emerging or disappearing) C IV broad absorption line (BAL) components in 50 radio detected QSOs using multi-epoch spectra available in Sloan Digital Sky Survey DR10. We report the detectionof 6 BALQSOs having at least one distinct transient C IV absorption component. Based on the structure function analysis of optical light curves, we suggest that the transient absorption is unlikely to be triggered by continuum variations. Transient absorption components usually have low C IV equivalent widths ( 10000 \\kms) and typically occur over rest-frame timescales > 800 days. The detection rate of transient C IV absorption seen in our sample is higher than that reported in the literature. Using a control sample of QSOs, we show that this difference is most likely due to the longer monitoring time-scale of sources in our sample while the effect of small number statistics cannot be ignored. Thus, in order to establish the role played by radio jets in driving the BAL outflows, we need a larger...

  10. Discovery of Broad Soft X-ray Absorption Lines from the Quasar Wind in PDS 456

    CERN Document Server

    Reeves, James; Nardini, Emanuele; Behar, Ehud; O'Brien, Paul; Tombesi, Francesco; Turner, Tracey Jane; Costa, Michele

    2016-01-01

    High resolution soft X-ray spectroscopy of the prototype accretion disk wind quasar, PDS 456, is presented. Here, the XMM-Newton RGS spectra are analyzed from the large 2013-2014 XMM-Newton campaign, consisting of 5 observations of approximately 100 ks in length. During the last observation (hereafter OBS. E), the quasar is at a minimum flux level and broad absorption line profiles are revealed in the soft X-ray band, with typical velocity widths of $\\sigma_{\\rm v}\\sim 10,000$ km s$^{-1}$. During a period of higher flux in the 3rd and 4th observations (OBS. C and D, respectively), a very broad absorption trough is also present above 1 keV. From fitting the absorption lines with models of photoionized absorption spectra, the inferred outflow velocities lie in the range $\\sim 0.1-0.2c$. The absorption lines likely originate from He and H-like neon and L-shell iron at these energies. Comparison with earlier archival data of PDS 456 also reveals similar absorption structure near 1 keV in a 40 ks observation in 20...

  11. Implications of Dramatic Broad Absorption Line Variability in the Quasar FBQS J1408+3054

    CERN Document Server

    Hall, Patrick B; White, R L; Brandt, W N; Gregg, M D; Gibson, R R; Becker, R H; Schneider, D P

    2010-01-01

    We have observed a dramatic change in the spectrum of the formerly heavily absorbed `overlapping-trough' iron low-ionization broad absorption line (FeLoBAL) quasar FBQS J1408+3054. Over a time span of between 0.6 to 5 rest-frame years, the Mg II trough outflowing at 12,000 km/s decreased in equivalent width by a factor of two and the Fe II troughs at the same velocity disappeared. The most likely explanation for the variability is that a structure in the BAL outflow moved out of our line of sight to the ultraviolet continuum emitting region of the quasar's accretion disk. Given the size of that region, this structure must have a transverse velocity of between 1300 km/s and 11,000 km/s. In the context of a simple outflow model, we show that this BAL structure is located between approximately 7300 and 73,000 Schwarzschild radii from the black hole. That distance corresponds to 2.2 to 22 pc, 14 to 140 times farther from the black hole than the H-beta broad-line region. The high velocities and the parsec-scale di...

  12. More Evidence for the Intermediate Broad Line Region of the Mapped AGN PG 0052+251

    CERN Document Server

    Zhang, XueGuang

    2013-01-01

    In the manuscript, the properties of the proposed intermediate BLR are checked for the mapped AGN PG 0052+251. With the considerations of the apparent effects of the broad He {\\sc ii} line on the observed broad H$\\beta$ profile, the line parameters (especially the line width and the line flux) of the observed broad H$\\alpha$ and the broad H$\\beta$ are carefully determined. Based on the measured line parameters, the model with two broad components applied for each observed broad balmer line is preferred, and then confirmed by the calculated much different time lags for the inner/intermediate broad components and the corresponding virial BH masses ratio determined by the properties of the inner and the intermediate broad components. Then, the correlation between the broad line width and the broad line flux is checked for the two broad components: one clearly strong negative correlation for the inner broad component, but one positive correlation for the intermediate broad component. The different correlations fo...

  13. Iron and zinc availability in maize lines

    Directory of Open Access Journals (Sweden)

    Valéria Aparecida Vieira Queiroz

    2011-09-01

    Full Text Available The aim of this study was to characterize the Zn and Fe availability by phytic acid/Zn and phytic acid/Fe molar ratios, in 22 tropical maize inbred lines with different genetic backgrounds. The Zn and Fe levels were determined by atomic absorption spectrophotometry and the P through colorimetry method. Three screening methods for phytic acid (Phy analysis were tested and one, based on the 2,2'-bipyridine reaction, was select. There was significant variability in the contents of zinc (17.5 to 42 mg.kg-1, iron (12.2 to 36.7 mg.kg-1, phosphorus (230 to 400 mg.100 g-1, phytic acid (484 to 1056 mg.100 g-1, phytic acid P (140 to 293 mg.100 g-1 and available-P (43.5 to 199.5 mg.100 g-1, and in the available-P/total-P ratio (0.14 to 0.50, Phy/Zn (18.0 to 43.5 and Phy/Fe (16.3 to 45.5 molar ratios. Lines 560977, 560978 and 560982 had greater availability of Zn and lines 560975, 560977, 561010 and 5610111 showed better Fe availability. Lines 560975, 560977 and 560978 also showed better available-P/total-P ratio. Thus, the lines 560975, 560977 and 560978 were considered to have the potential for the development of cultivars of maize with high availability of Fe and/or Zn.

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

    CERN Document Server

    Porquet, D; Dumont, A M

    2000-01-01

    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.

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

    Science.gov (United States)

    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.

  16. Dependence of the broad Fe Kα line on the physical parameters of AGN

    Science.gov (United States)

    Liu, Zhu; Yuan, Weimin; Lu, Youjun; Carrera, Francisco J.; Falocco, Serena; Dong, Xiao-Bo

    2016-08-01

    In this paper, the dependence of the broad Fe Kα line on the physical parameters of AGN, such as the black hole mass MBH, accretion rate (equivalently represented by Eddington ratio λEdd), and optical classification, is investigated by applying the X-ray spectra stacking method to a large sample of AGN which have well measured optical parameters. A broad line feature is detected (>3σ) in the stacked spectra of the high λEdd sub-sample (log λEdd > -0.9). The profile of the broad line can be well fitted with relativistic broad line model, with the line energy consistent with highly ionized Fe Kα line (i.e. Fe XXVI). A model consisting of multiple narrow lines cannot be ruled out, however. We found hints that the Fe K line becomes broader as the λEdd increases. No broad line feature is shown in the sub-sample of broad-line Seyfert 1 (BLS1) galaxies and in the full sample, while a broad line might be present, though at low significance, in the sub-sample of narrow-line Seyfert 1 (NLS1) galaxies. We find no strong dependence of the broad line on black hole masses. Our results indicate that the detection/properties of the broad Fe Kα line may strongly depend on λEdd, which can be explained if the ionization state and/or truncation radius of the accretion disc changes with λEdd. The non-detection of the broad line in the BLS1 sub-sample can be explained if the the average EW of the relativistic Fe Kα line is weak or/and the fraction of sources with relativistic Fe Kα line is small in BLS1 galaxies.

  17. Interpreting broad emission-line variations I : Factors influencing the emission-line response

    CERN Document Server

    Goad, M R

    2014-01-01

    We investigate the sensitivity of the measured broad emission-line responsivity dlog f_line/dlog f_cont to continuum variations in the context of straw-man BLR geometries of varying size with fixed BLR boundaries, and for which the intrinsic emission-line responsivity is known a priori. We find for a generic emission-line that the measured responsivity, delay and maximum of the cross-correlation function are correlated for characteristic continuum variability timescales T_char less than the maximum delay for that line tau_max(line) for a particular choice of BLR geometry and observer orientation. The above correlations are manifestations of geometric dilution arising from reverberation effects within the spatially extended BLR. When present, geometric dilution reduces the measured responsivity, delay and maximum of the cross-correlation function. We also find that the measured responsivity and delay show a strong dependence on light-curve duration, with shorter campaigns resulting in smaller than expected val...

  18. The High Energy view of the Broad Line Radio Galaxy 3C 111

    CERN Document Server

    Ballo, L; Reeves, J N; Sambruna, R M; Tombesi, F

    2011-01-01

    We present the analysis of Suzaku and XMM-Newton observations of the broad-line radio galaxy (BLRG) 3C 111. Its high energy emission shows variability, a harder continuum with respect to the radio quiet AGN population, and weak reflection features. Suzaku found the source in a minimum flux level; a comparison with the XMM-Newton data implies an increase of a factor of 2.5 in the 0.5-10 keV flux, in the 6 months separating the two observations. The iron K complex is detected in both datasets, with rather low equivalent width(s). The intensity of the iron K complex does not respond to the change in continuum flux. An ultra-fast, high-ionization outflowing gas is clearly detected in the XIS data; the absorber is most likely unstable. Indeed, during the XMM-Newton observation, which was 6 months after, the absorber was not detected. No clear roll-over in the hard X-ray emission is detected, probably due to the emergence of the jet as a dominant component in the hard X-ray band, as suggested by the detection above...

  19. DISCOVERY OF THE TRANSITION OF A MINI-BROAD ABSORPTION LINE INTO A BROAD ABSORPTION LINE IN THE SDSS QUASAR J115122.14+020426.3

    Energy Technology Data Exchange (ETDEWEB)

    Hidalgo, Paola Rodriguez; Eracleous, Michael; Charlton, Jane [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States); Hamann, Fred [Department of Astronomy, University of Florida, Gainesville, FL 32611 (United States); Murphy, Michael T. [Center for Astrophysics and Supercomputing, Swinburne University of Technology, P.O. Box 218, Hawthorn, Victoria 3122 (Australia); Nestor, Daniel [Department of Physics and Astronomy, University of California, 430 Portola Plaza, Box 951547, Los Angeles, CA 90095 (United States)

    2013-09-20

    We present the detection of a rare case of dramatic strengthening in the UV absorption profiles in the spectrum of the quasar J115122.14+020426.3 between observations {approx}2.86 yr apart in the quasar rest frame. A spectrum obtained in 2001 by the Sloan Digital Sky Survey shows a C IV ''mini-broad'' absorption line (FWHM = 1220 km s{sup -1}) with a maximum blueshift velocity of {approx}9520 km s{sup -1}, while a later spectrum from the Very Large Telescope shows a significantly broader and stronger absorption line, with a maximum blueshift velocity of {approx}12, 240 km s{sup -1} that qualifies as a broad absorption line. A similar variability pattern is observed in two additional systems at lower blueshifted velocities and in the Ly{alpha} and N V transitions as well. One of the absorption systems appears to be resolved and shows evidence for partial covering of the quasar continuum source (C{sub f} {approx} 0.65), indicating a transverse absorber size of, at least, {approx}6 Multiplication-Sign 10{sup 16} cm. In contrast, a cluster of narrower C IV lines appears to originate in gas that fully covers the continuum and broad emission line sources. There is no evidence for changes in the centroid velocity of the absorption troughs. This case suggests that at least some of the absorbers that produce ''mini-broad'' and broad absorption lines in quasar spectra do not belong to intrinsically separate classes. Here, the ''mini-broad'' absorption line is most likely interpreted as an intermediate phase before the appearance of a broad absorption line due to their similar velocities. While the current observations do not provide enough constraints to discern among the possible causes for this variability, future monitoring of multiple transitions at high resolution will help achieve this goal.

  20. Dependence of the broad Fe K$\\alpha$ line on the physical parameters of AGN

    CERN Document Server

    Liu, Zhu; Lu, Youjun; Carrera, Francisco J; Falocco, Serena; Dong, Xiao-Bo

    2016-01-01

    In this paper, the dependence of the broad Fe K$\\alpha$ line on the physical parameters of AGN, such as the black hole mass $M_{BH}$, accretion rate (equivalently represented by Eddington ratio $\\lambda_{Edd}$), and optical classification, is investigated by applying the X-ray spectra stacking method to a large sample of AGN which have well measured optical parameters. A broad line feature is detected ($>3\\sigma$) in the stacked spectra of the high $\\lambda_{Edd}$ sub-sample ($\\log\\lambda_{Edd}>-0.9$). The profile of the broad line can be well fitted with relativistic broad line model, with the line energy consistent with highly ionized Fe K$\\alpha$ line (i.e. Fe xxvi). A model consisting of multiple narrow lines cannot be ruled out, however. We found hints that the Fe K line becomes broader as the $\\lambda_{Edd}$ increases. No broad line feature is shown in the sub-sample of broad-line Seyfert 1 (BLS1) galaxies and in the full sample, while a broad line might be present, though at low significance, in the su...

  1. Iron emission line from the spiral galaxy M101

    CERN Document Server

    Yamauchi, Shigeo

    2015-01-01

    Archival Suzaku data of the face-on spiral galaxy M101 were analyzed. An intense emission line at 6.72^{+0.10}_{-0.12} keV was detected in the central region. This line is identified with a K-line from He-like iron, which indicates the existence of a thin thermal plasma with a temperature of several keV. The iron line luminosity within the central 5 arcmin radius region is estimated to be (2-12)x10^{37} erg s^{-1}. The origin of the iron emission line is discussed.

  2. Anisotropy in broad component of H$\\alpha$ line in the magnetospheric device RT-1

    CERN Document Server

    Kawazura, Yohei; Yoshida, Zensho; Nishiura, Masaki; Nogami, Tomoaki; Kashyap, Ankur; Yano, Yoshihisa; Saitoh, Haruhiko; Yamasaki, Miyuri; Mushiake, Toshiki; Nakatsuka, Masataka

    2016-01-01

    Temperature anisotropy in broad component of H$\\alpha$ line was found in the ring trap 1 (RT-1) device by Doppler spectroscopy. Since hot hydrogen neutrals emitting a broad component are mainly produced by charge exchange between neutrals and protons, the anisotropy in the broad component is the evidence of proton temperature anisotropy generated by betatron acceleration.

  3. Broad emission lines variability: a window into the heart of AGN

    Science.gov (United States)

    Ilic, Dragana; Popovic, Luka C.; Shapovalova, Alla I.; Afanasiev, V. L.; Chavushyan, V. H.; Burenkov, A.; Kollatschny, W.; Kovacevic, A.

    2016-08-01

    The broad emission lines of active galactic nuclei (AGN) are known to vary both in flux and shape, and are often showing very complex line profiles. They can give us invaluable information about the kinematics and geometry of the broad line region (BLR) where these lines are originating from. The BLR is close to the supermassive black hole in AGN and may hold basic information about the formation and fueling of AGN.Here we summarize the results of the line and continuum variability of a sample of broad line AGN, obtained with the long-term optical monitoring campaign performed with telescopes of SAO (Russia), OAGH and OAN-SPM (Mexico), and Calar Alto (Spain). We monitored different type of broad line AGN (double-peaked, radio loud and radio quiet, NLSy1 and a supermassive binary black hole candidate) which show different variability characteristics that can be explained by different physical properties in BLR.

  4. Bloated stars as agn broad line clouds the emission line spectrum

    CERN Document Server

    Alexander, T; Tal Alexander; Hagai Netzer

    1994-01-01

    The `Bloated Stars Scenario' proposes that AGN broad line emission originates in the winds or envelopes of bloated stars (BS). Its main advantage over BLR cloud models is the gravitational confinement of the gas and its major difficulty the large estimated number of BSs and resulting high mass loss rate. We calculate the emission line spectrum by a detailed numerical photoionization code for a wide range of wind structures and a detailed QSO nucleus model with L(ion)=7E45 erg/s, M(bh)=8E7 Mo. The size and boundary density of the BS wind are determined by various processes: Comptonization by the central continuum source, calculated self consistently, tidal disruption by the black hole and the limit set by the wind's finite mass. We find that the emission spectrum is mainly determined by the conditions at the boundary of the line emitting fraction of the wind rather than by its internal structure. Comptonization results in very high ionization parameters at the boundary which produces an excess of unobserved br...

  5. To test dual supermassive black hole model for broad line AGN with double-peaked narrow [OIII] lines

    CERN Document Server

    XueGuang, Zhang

    2016-01-01

    In this manuscript, we proposed an interesting method to test the dual supermassive black hole model for AGN with double-peaked narrow \\oiii lines (double-peaked narrow emitters), through their broad optical Balmer line properties. Under the dual supermassive black hole model for double-peaked narrow emitters, we could expect statistically smaller virial black hole masses estimated by observed broad Balmer line properties than true black hole masses (total masses of central two black holes). Then, we compare the virial black hole masses between a sample of 37 double-peaked narrow emitters with broad Balmer lines and samples of SDSS selected normal broad line AGN with single-peaked \\oiii lines. However, we can find clearly statistically larger calculated virial black hole masses for the 37 broad line AGN with double-peaked \\oiii lines than for samples of normal broad line AGN. Therefore, we give our conclusion that the dual supermassive black hole model is probably not statistically preferred to the double-pea...

  6. Gravitational microlensing of quasar Broad Line Regions: the influence of fractal structures

    CERN Document Server

    Lewis, G F; Lewis, Geraint F.; Ibata, Rodrigo A.

    2006-01-01

    Recent models for the emission clouds within the Broad Line Region of quasars suggest that they are due to transient overdensities within an overall turbulent medium. If this were the case, the broad line emission would spatially appear fractal, possessing structure on a range of scales. This paper examines the influence of such fractal structure when a quasar is microlensed by a population of intervening masses. It is found that while the highest fractal levels can undergo significant microlensing magnification, when these light curves are superimposed to create an emission line profile, the resultant emission line profile remains relatively constant for physical models of the Broad Line Region. It is concluded that the detection of the possible fractal structure of Broad Line Regions via gravitational microlensing is not practical.

  7. Broad emission lines variability: a window into the heart of AGN

    OpenAIRE

    Ilic, Dragana; Popovic, Luka C.; Shapovalova, Alla I.; Afanasiev, V.L.; V. H. Chavushyan; Burenkov, A.; Kollatschny, W.; Kovacevic, A.

    2016-01-01

    The broad emission lines of active galactic nuclei (AGN) are known to vary both in flux and shape, and are often showing very complex line profiles. They can give us invaluable information about the kinematics and geometry of the broad line region (BLR) where these lines are originating from. The BLR is close to the supermassive black hole in AGN and may hold basic information about the formation and fueling of AGN. Here we summarize the results of the line and continuum variability of a ...

  8. A tunable dual-broad-band branch-line coupler utilizing composite right/left-handed transmission lines

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yu; HU Li; HE Sai-ling

    2005-01-01

    A tunable dual-broad-band branch-line coupler (BLC) utilizing composite right/left-handed (CRLH) transmission lines is presented. Two λ/4 segments consisting of CRLH transmission lines are added to each port to broaden the dual bands of the branch-line coupler. Numerical simulation and optimal design of the novel coupler are presented. The dual bands of the novel coupler are tunable and broad. The 1-dB bandwidth of each passband is more than 16% of the central frequency.

  9. Are broad optical balmer lines from central accretion disk in PG 1613+658?

    CERN Document Server

    Zhang, XueGuang

    2014-01-01

    In this letter, we report positive correlations between broad line width and broad line flux for the broad balmer lines of the long-term observed AGN PG 1613+658. Rather than the expected negative correlations under the widely accepted virialization assumption for AGN BLRs, the positive correlations indicate much different BLR structures of PG 1613+658 from the commonly considered BLR structures which are dominated by the equilibrium between radiation pressure and gas pressure. Therefore, accretion disk origin is preferred for the observed broad single-peaked optical balmer lines of PG 1613+658, because of the mainly gravity dominated disk-like BLRs with radial structures having few effects from radiation pressure.

  10. Constraints on the outer radius of the broad emission line region of active galactic nuclei

    CERN Document Server

    Landt, Hermine; Elvis, Martin; Karovska, Margarita

    2014-01-01

    Here we present observational evidence that the broad emission line region (BELR) of active galactic nuclei (AGN) generally has an outer boundary. This was already clear for sources with an obvious transition between the broad and narrow components of their emission lines. We show that the narrow component of the higher-order Paschen lines is absent in all sources, revealing a broad emission line profile with a broad, flat top. This indicates that the BELR is kinematically separate from the narrow emission line region. We use the virial theorem to estimate the BELR outer radius from the flat top width of the unblended profiles of the strongest Paschen lines, Pa alpha and Pa beta, and find that it scales with the ionising continuum luminosity roughly as expected from photoionisation theory. The value of the incident continuum photon flux resulting from this relationship corresponds to that required for dust sublimation. A flat-topped broad emission line profile is produced by both a spherical gas distribution ...

  11. The origin of the strong soft excess and puzzling iron line complex in Mkn 841

    CERN Document Server

    Petrucci, P O; Matt, G; Maraschi, L; Malzac, J; Mouchet, M; Boisson, C; Longinotti, A; Nandra, K; Ferrando, P; Henri, G

    2006-01-01

    Mkn 841 has been observed during 3 different periods (January 2001, January 2005 and July 2005) by XMM-Newton for a total cumulated exposure time of ~108 ks. We present in this paper a broad band spectral analysis of the complete EPIC-pn data sets. These observations confirm the presence of the strong soft excess and complex iron line profile known to be present in this source since a long time. They also reveal their extreme and puzzling spectral and temporal behaviors. Indeed, the 0.5-2 keV soft X-ray flux decreases by a factor 3 between 2001 and 2005 and the line shape appears to be a mixed of broad and narrow components, both variable but on differen timescales. The broad-band 0.5-10 keV spectra are well described by a model including a primary power law continuum, a blurred photoionized reflection and a narrow iron line, the blurred reflection fitting self-consistently the soft excess and the broad line component. The origin and nature of the narrow component is unclear.

  12. Unusual broad-line Mg II emitters among luminous galaxies in the baryon oscillation spectroscopic survey

    International Nuclear Information System (INIS)

    Many classes of active galactic nuclei (AGNs) have been observed and recorded since the discovery of Seyfert galaxies. In this paper, we examine the sample of luminous galaxies in the Baryon Oscillation Spectroscopic Survey. We find a potentially new observational class of AGNs, one with strong and broad Mg II λ2799 line emission, but very weak emission in other normal indicators of AGN activity, such as the broad-line Hα, Hβ, and the near-ultraviolet AGN continuum, leading to an extreme ratio of broad Hα/Mg II flux relative to normal quasars. Meanwhile, these objects' narrow-line flux ratios reveal AGN narrow-line regions with levels of activity consistent with the Mg II fluxes and in agreement with that of normal quasars. These AGN may represent an extreme case of the Baldwin effect, with very low continuum and high equivalent width relative to typical quasars, but their ratio of broad Mg II to broad Balmer emission remains very unusual. They may also be representative of a class of AGN where the central engine is observed indirectly with scattered light. These galaxies represent a small fraction of the total population of luminous galaxies (≅ 0.1%), but are more likely (about 3.5 times) to have AGN-like nuclear line emission properties than other luminous galaxies. Because Mg II is usually inaccessible for the population of nearby galaxies, there may exist a related population of broad-line Mg II emitters in the local universe which is currently classified as narrow-line emitters (Seyfert 2 galaxies) or low ionization nuclear emission-line regions.

  13. Hints of Correlations Between Broad-Line and Radio Variations for AGNs

    CERN Document Server

    Liu, H T; Feng, H C; Li, S K

    2014-01-01

    In this paper, we study the issue of correlation between broad-line and radio variations under a spherical broad-line region (BLR), and attempt to locate the position of radio (and gamma-ray) emitting region in jet of radio-loud active galactic nuclei (AGNs). Considering the radial profiles of the radius and number density of clouds in the spherical BLR, we have deduced new formulae connecting the radio emitting position $R_{\\rm{jet}}$ to the time lags $\\tau_{\\rm{ob}}$ between broad-line and radio variations, and the BLR inner and outer radii. The new formulae are applied to broad-line radio-loud Fermi-LAT AGNs, 3C 273 and 3C 120. For 3C 273, a common feature of negative time lags is found in the cross-correlation functions between light curves of radio emission and the Balmer lines, and as well Ly$\\alpha$ $\\lambda 1216$ and C IV $\\lambda 1549$ lines. $R_{\\rm{jet}}=$ 1.0--2.6 parsec (pc) are obtained from the time lags of the Balmer lines. For 3C 120, positive lags of about 0.3 yr are found between the 15 GHz...

  14. Diagnostics for the structure of AGNs’broad line regions with reverberation mapping data:confirmation of the two-component broad line region model

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    We re-examine the ten Reverberation Mapping(RM) sources with public data based on the two-component model of the Broad Line Region(BLR).In fitting their broad Hβ Mlines,six of them only need one Gaussian component,one of them has a double-peak profile,one has an irregular profile,and only two of them need two components,i.e.,a Very Broad Gaussian Component(VBGC) and an Inter-Mediate Gaussian Component(IMGC).The Gaussian components are assumed to come from two distinct regions in the two-component model;they are the Very Broad Line Region(VBLR) and the Inter-Mediate Line region(IMLR).The two sources with a two-component profile are Mrk 509 and NGC 4051.The time lags of the two components of both sources satisfy tIMLR/tVBLR=V 2VBLR/V 2IMLR,where tIMLR and tVBLR are the lags of the two components while VIMLR and VVBLR represent the mean gas velocities of the two regions,supporting the two-component model of the BLR of Active Galactic Nuclei(AGNs).The fact that most of these ten sources only have the VBGC confirms the assumption that RM mainly measures the radius of the VBLR;consequently,the radius obtained from the R-L relationship mainly represents the radius of VBLR.Moreover,NGC 4051,with a lag of about 5 days in the one component model,is an outlier on the R-L relationship as shown in Kaspi et al.(2005);however this problem disappears in our two-component model with lags of about 2 and 6 days for the VBGC and IMGC,respectively.

  15. Correlation between Line Width and Line Flux of Double-Peaked Broad Halpha of 3C390.3

    CERN Document Server

    Zhang, XueGuang

    2012-01-01

    In this manuscript, we carefully check the correlation between the line width and the line flux of the double-peaked broad H$\\alpha$ of the well-known mapped AGN 3C390.3, in order to show some further distinctions between double-peaked emitters and normal broad line AGN. Based on the Virialization assumption and the empirical relation about $R_{BLR}$, one strong negative correlation of line parameters of the double-peaked broad lines should be expected for 3C390.3, such as the negative correlation confirmed for the mapped broad line object NGC5548. But, based on the public spectra around 1995 from the AGNWATCH project for 3C390.3, one reliable positive correlation is found. In the context of the proposed theoretical accretion disk model for double-peaked emitters, the unexpected positive correlation can be naturally explained, due to different time delays for inner parts and outer parts of disk-like BLR of 3C390.3. Moreover, the Virialization assumption is checked and found to be still available for 3C390.3. ...

  16. Iron forbidden lines in tokamak discharges

    International Nuclear Information System (INIS)

    Several spectrum lines from forbidden transitions in the ground configurations of highly ionized atoms have been observed in the PLT tokamak discharges. Such lines allow localized observations, in the high-temperature regions of the plasma, of ion-temperatures, plasma motions, and spatial distributions of ions. Measured absolute intensities of the forbidden lines have been compared with simultaneous observations of the ion resonance lines and with model calculations in order to deduce the mechanism of level populaions by means of electron collisions and radiative transitions

  17. Origin of the X-ray Broad Iron Spectral Feature in GRS 1915+105

    CERN Document Server

    Mizumoto, Misaki; Tsujimoto, Masahiro; Inoue, Hajime

    2015-01-01

    The X-ray spectrum of GRS 1915+105 is known to have a ``broad iron spectral feature'' in the spectral hard state. Similar spectral features are often observed in Active Galactic Nuclei (AGNs) and other black-hole binaries (BHBs), and several models have been proposed for explaining it. In order to distinguish spectral models, time variation provides an important key. In AGNs, variation amplitude has been found to drop significantly at the iron K-energy band at timescales of ~10 ks. If spectral variations of black-holes are normalized by their masses, the spectral variations of BHBs at timescales of sub-seconds should exhibit similar characteristics to those of AGNs. In this paper, we investigated spectral variations of GRS 1915+105 at timescales down to ~10 ms. This was made possible for the first time with the Suzaku XIS Parallel-sum clocking (P-sum) mode, which has the CCD energy-resolution as well as a time-resolution of 7.8 ms. Consequently, we found that the variation amplitude of GRS 1915+105 does not d...

  18. BROAD Hβ EMISSION-LINE VARIABILITY IN A SAMPLE OF 102 LOCAL ACTIVE GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Runco, Jordan N.; Cosens, Maren; Bennert, Vardha N.; Scott, Bryan [Physics Department, California Polytechnic State University, San Luis Obispo CA 93407 (United States); Komossa, S. [Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121, Bonn (Germany); Malkan, Matthew A.; Treu, Tommaso [Department of Physics, University of California, Los Angeles, CA 90095 (United States); Lazarova, Mariana S. [Department of Physics and Physical Science, University of Nebraska Kearney, Kearney, NE 68849 (United States); Auger, Matthew W. [Institute of Astronomy, Madingley Road, Cambridge CB3 0HA (United Kingdom); Park, Daeseong, E-mail: jrunco@calpoly.edu, E-mail: mcosens@calpoly.edu, E-mail: vbennert@calpoly.edu, E-mail: malkan@astro.ucla.edu, E-mail: tt@physics.ucsb.edu, E-mail: lazarovam2@unk.edu, E-mail: mauger@ast.cam.ac.uk, E-mail: daeseongpark@kasi.re.kr [Korea Astronomy and Space Science Institute, Daejeon, 34055 (Korea, Republic of)

    2016-04-10

    A sample of 102 local (0.02 ≤ z ≤ 0.1) Seyfert galaxies with black hole masses M{sub BH} > 10{sup 7}M{sub ⊙} was selected from the Sloan Digital Sky Survey (SDSS) and observed using the Keck 10 m telescope to study the scaling relations between M{sub BH} 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 M{sub BH}, 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 broadline 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.

  19. Reverberation Mapping of the Broad-line Region in NGC 5548: Evidence for Radiation Pressure?

    CERN Document Server

    Lu, Kai-Xing; Hu, Chen; Li, Yan-Rong; Zhang, Zhi-Xiang; Wang, Kai; Huang, Ying-Ke; Bi, Shao-Lan; Bai, Jin-Ming; Ho, Luis C; Wang, Jian-Min

    2016-01-01

    NGC 5548 is the best-observed reverberation-mapped active galactic nucleus with long-term, intensive monitoring. Here we report results from a new observational campaign between January and July, 2015. We measure the centroid time lag of the broad H$\\beta$ emission line with respect to the 5100 \\AA continuum and obtain $\\tau_{\\rm cent} = 7.20^{+1.33}_{-0.35}$ days in the rest frame. This yields a black hole mass of $M_{\\bullet}=8.71^{+3.21}_{-2.61} $x$ 10^{7}M_{\\odot}$ using a broad H$\\beta$ line dispersion of $3124\\pm302$ km s$^{-1}$ and a virial factor of $f_{_{\\rm BLR}}=6.3\\pm1.5$ for the broad-line region (BLR), consistent with the mass measurements from previous H$\\beta$ campaigns. The high-quality data allow us to construct a velocity-binned delay map for the broad H$\\beta$ line, which shows a symmetric response pattern around the line center, a plausible kinematic signature of virialized motion of the BLR. Combining all the available measurements of H$\\beta$ time lags and the associated mean 5100 {\\AA}...

  20. Reverberation Mapping of the Broad-line Region in NGC 5548: Evidence for Radiation Pressure?

    Science.gov (United States)

    Lu, Kai-Xing; Du, Pu; Hu, Chen; Li, Yan-Rong; Zhang, Zhi-Xiang; Wang, Kai; Huang, Ying-Ke; Bi, Shao-Lan; Bai, Jin-Ming; Ho, Luis C.; Wang, Jian-Min

    2016-08-01

    NGC 5548 is the best-observed reverberation-mapped active galactic nucleus with long-term, intensive monitoring. Here we report results from a new observational campaign between 2015 January and July. We measure the centroid time lag of the broad Hβ emission line with respect to the 5100 Å continuum and obtain {τ }{{cent}}={7.20}-0.35+1.33 days in the rest frame. This yields a black hole mass of {M}\\bullet ={8.71}-2.61+3.21× {10}7{M}ȯ using a broadline dispersion of 3124 ± 302 km s‑1 and a virial factor of {f}{{{BLR}}}=6.3+/- 1.5 for the broad-line region (BLR), consistent with the mass measurements from previous Hβ campaigns. The high-quality data allow us to construct a velocity-binned delay map for the broadline, which shows a symmetric response pattern around the line center, a plausible kinematic signature of virialized motion of the BLR. Combining all the available measurements of Hβ time lags and the associated mean 5100 Å luminosities over 18 campaigns between 1989 and 2015, we find that the Hβ BLR size varies with the mean optical luminosity, but, interestingly, with a possible delay of {2.35}-1.25+3.47 years. This delay coincides with the typical BLR dynamical timescale of NGC 5548, indicating that the BLR undergoes dynamical changes, possibly driven by radiation pressure.

  1. X-Ray Iron Line Constraints on the Inner Accretion Disk and Black Hole Spin

    Science.gov (United States)

    Reynolds, C. S.

    2000-01-01

    The broad iron line, seen in the X-ray spectra of many AGN, is thought to originate from the inner regions of the black hole accretion disk. I will summarize recent developments in using this line to probe the accretion disk structure, as well as the mass and spin of black holes n Seyfert galaxies. In particular, I will present observational evidence suggesting that the inner regions of the accretion disks in low-luminosity AGN (LLAGN) are distinctly different from those in higher-luminosity AGN. This tentative result lends support models of LLAGN based upon advective accretion disks.

  2. Broad-line region structure and kinematics in the radio galaxy 3C 120

    Science.gov (United States)

    Kollatschny, W.; Ulbrich, K.; Zetzl, M.; Kaspi, S.; Haas, M.

    2014-06-01

    Context. Broad emission lines originate in the surroundings of supermassive black holes in the centers of active galactic nuclei (AGN). These broad-line emitting regions are spatially unresolved even for the nearest AGN. The origin and geometry of broad-line region (BLR) gas and their connection with geometrically thin or thick accretion disks is of fundamental importance for the understanding of AGN activity. Aims: One method to investigate the extent, structure, and kinematics of the BLR is to study the continuum and line profile variability in AGN. We selected the radio-loud Seyfert 1 galaxy 3C 120 as a target for this study. Methods: We took spectra with a high signal-to-noise ratio of 3C 120 with the 9.2 m Hobby-Eberly Telescope between Sept. 2008 and March 2009. In parallel, we photometrically monitored the continuum flux at the Wise observatory. We analyzed the continuum and line profile variations in detail (1D and 2D reverberation mapping) and modeled the geometry of the line-emitting regions based on the line profiles. Results: We show that the BLR in 3C 120 is stratified with respect to the distance of the line-emitting regions from the center with respect to the line widths (FWHM) of the rms profiles and with respect to the variability amplitude of the emission lines. The emission line wings of Hα and Hβ respond much faster than their central region. This is explained by accretion disk models. In addition, these lines show a stronger response in the red wings. However, the velocity-delay maps of the helium lines show a stronger response in the blue wing. Furthermore, the He ii λ4686 line responds faster in the blue wing in contradiction to observations made one and a half years later when the galaxy was in a lower state. The faster response in the blue wing is an indication for central outflow motions when this galaxy was in a bright state during our observations. The vertical BLR structure in 3C 120 coincides with that of other AGN. We confirm the

  3. Iron Line Profiles in Strong Gravity

    CERN Document Server

    Beckwith, K; Beckwith, Kris; Done, Chris

    2004-01-01

    We describe a new code which can accurately calculate the relativistic effects which distort the emission from an accretion disc around a black hole. We compare our results for a disk from 6-20r_g in both Schwarzchild and extreme Kerr spacetimes with the two line profile codes which are on general release in the XSPEC spectral fitting package. These are generally accurate at the 10-20% level for this range of radii, but have some drawbacks in terms of assumptions and/or resolution. In particular we show that the assumed form of the angular emissivity law (limb darkening or brightening) can make significant changes to the derived line profile. Lightbending effects are never negligible at these radii, so the observed line is produced from a range of different emitted angles, and this can affect the derived radial emissivity law. The line profile is not simply determined by the well defined (but numerically difficult) physical effects of strong gravity, but is also dependent on the poorly known astrophysics of t...

  4. Broad Hbeta Emission-Line Variability in a Sample of 102 Local Active Galaxies

    CERN Document Server

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

    2016-01-01

    A sample of 102 local (0.02 10^7 M_sun 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 Hbeta emission line within the ~3-9 year time-frame between the two sets of spectra. The variability of the broad Hbeta emission line is of particular interest, not only since it is used to estimate MBH, but also since its strength and width is 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 Hbeta line virtually disappears in 3/102 (~3%) extreme cases. We discuss potential causes for these changing-look AGNs. While similar dramatic transitions have previously been reported in the literature, either on a case-by-case ...

  5. Line profiles of the two-phase medium broad-line region in active galactic nuclei

    Institute of Scientific and Technical Information of China (English)

    薛随建; 林宣滨; 程福臻; John Kwan

    1996-01-01

    In the framework of BLR in AGNs, i.e. large number of small, cold and dense emission-line clouds immerging in an intercloud hot medium, a delicate radiation model for a typical emission cloud is established, in which the backside photoionization of the cloud against the central continuum source by the scattered diffuse continuum in the hot medium is considered. Under the assumption of the radial kinematics of the BLR clouds, the line profiles for the two important UV emission-lines, Lya and CIV/11549 are computed; and based on these calculations, various physical factors that affect the properties of the emission-line profiles are discussed. It is concluded that: (i) when the BLR clouds is inflow, there exists a confining hot medium with density around 2 x 105 cm-3. In this case, theoretical line profiles agree well with the observational; (ii) both symmetric Lya and nearly symmetric CIV line profiles show blue velocity shifts, the quantities of which are sensitive to the cutoff of the outer radius of t

  6. The Lick AGN Monitoring Project: Alternate Routes to a Broad-line Region Radius

    CERN Document Server

    Greene, Jenny E; Barth, Aaron J; Bennert, Vardha N; Bentz, Misty C; Filippenko, Alexei V; Gates, Elinor; Malkan, Matthew A; Treu, Tommaso; Walsh, Jonelle L; Woo, Jong-Hak

    2010-01-01

    It is now possible to estimate black hole masses across cosmic time, using broad emission lines in active galaxies. This technique informs our views of how galaxies and their central black holes coevolve. Unfortunately, there are many outstanding uncertainties associated with these "virial" mass estimates. One of these comes from using the accretion luminosity to infer a size for the broad-line region. Incorporating the new sample of low-luminosity active galaxies from our recent monitoring campaign at Lick Observatory, we recalibrate the radius-luminosity relation with tracers of the accretion luminosity other than the optical continuum. We find that the radius of the broad-line region scales as the square root of the X-ray and Hbeta luminosities, in agreement with recent optical studies. On the other hand, the scaling appears to be marginally steeper with narrow-line luminosities. This is consistent with a previously observed decrease in the ratio of narrow-line to X-ray luminosity with increasing total lum...

  7. A z ~ 5.7 Ly{\\alpha} Emission Line with an Ultra Broad Red Wing

    CERN Document Server

    Yang, Huan; Zheng, Zhen-Ya; Malhotra, Sangeeta; Rhoads, James E; Infante, Leopoldo

    2014-01-01

    Using Ly{\\alpha} emission line as a tracer of high redshift star forming galaxies, hundreds of Ly{\\alpha} emission line galaxies (LAEs) at z > 5 have been detected. These LAEs are considered to be low mass young galaxies, critical to the reionization of the universe and the metal enrichment of circumgalactic medium (CGM) and intergalactic medium (IGM). It is assumed that outflows in LAEs can help ionizing photons and Ly{\\alpha} photons escape out of galaxies. However we still know little about the outflows in high redshifts LAEs due to observational difficulties, especially at redshift > 5. Models of Ly{\\alpha} radiative transfer predict asymmetric Ly{\\alpha} line profiles with broad red wing in LAEs with outflows. Here we report a z ~ 5.7 Ly{\\alpha} emission line with a broad red wing extending to > 1000 km/s relative to the peak of Ly{\\alpha} line, which has been detected in only a couple of z > 5 LAEs till now. If the broad red wing is ascribed to gas outflow instead of AGN activity, the outflow velocity c...

  8. Iron and zinc availability in maize lines

    OpenAIRE

    Valéria Aparecida Vieira Queiroz; Paulo Evaristo de Oliveira Guimarães; Luciano Rodrigues Queiroz; Estefânia de Oliveira Guedes; Vanessa Diniz Barcelos Vasconcelos; Lauro José Guimarães; Paulo Eduardo de Aquino Ribeiro; Robert Eugene Schaffert

    2011-01-01

    The aim of this study was to characterize the Zn and Fe availability by phytic acid/Zn and phytic acid/Fe molar ratios, in 22 tropical maize inbred lines with different genetic backgrounds. The Zn and Fe levels were determined by atomic absorption spectrophotometry and the P through colorimetry method. Three screening methods for phytic acid (Phy) analysis were tested and one, based on the 2,2'-bipyridine reaction, was select. There was significant variability in the contents of zinc (17.5 to...

  9. The Sloan Digital Sky Survey Reverberation Mapping Project: Rapid CIV Broad Absorption Line Variability

    Science.gov (United States)

    Grier, C. J.; Hall, P. B.; Brandt, W. N.; Trump, J. R.; Shen, Yue; Vivek, M.; Filiz Ak, N.; Chen, Yuguang; Dawson, K. S.; Denney, K. D.; Green, Paul J.; Jiang, Linhua; Kochanek, C. S.; McGreer, Ian D.; Pâris, I.; Peterson, B. M.; Schneider, D. P.; Tao, Charling; Wood-Vasey, W. M.; Bizyaev, Dmitry; Ge, Jian; Kinemuchi, Karen; Oravetz, Daniel; Pan, Kaike; Simmons, Audrey

    2015-06-01

    We report the discovery of rapid variations of a high-velocity C iv broad absorption line trough in the quasar SDSS J141007.74+541203.3. This object was intensively observed in 2014 as a part of the Sloan Digital Sky Survey Reverberation Mapping Project, during which 32 epochs of spectroscopy were obtained with the Baryon Oscillation Spectroscopic Survey spectrograph. We observe significant (>4σ) variability in the equivalent width (EW) of the broad (˜4000 km s-1 wide) C iv trough on rest-frame timescales as short as 1.20 days (˜29 hr), the shortest broad absorption line variability timescale yet reported. The EW varied by ˜10% on these short timescales, and by about a factor of two over the duration of the campaign. We evaluate several potential causes of the variability, concluding that the most likely cause is a rapid response to changes in the incident ionizing continuum. If the outflow is at a radius where the recombination rate is higher than the ionization rate, the timescale of variability places a lower limit on the density of the absorbing gas of ne ≳ 3.9 × 105 cm-3. The broad absorption line variability characteristics of this quasar are consistent with those observed in previous studies of quasars, indicating that such short-term variability may in fact be common and thus can be used to learn about outflow characteristics and contributions to quasar/host-galaxy feedback scenarios.

  10. Weak line quasars at high redshift: extremely high accretion rates or anemic broad-line regions?

    NARCIS (Netherlands)

    O. Shemmer; B. Trakhtenbrot; S.F. Anderson; W.N. Brandt; A.M. Diamond-Stanic; X. Fan; P. Lira; H. Netzer; R.M. Plotkin; G.T. Richards; D.P. Schneider; M.A. Strauss

    2010-01-01

    We present Gemini-North K-band spectra of two representative members of the class of high-redshift quasars with exceptionally weak rest-frame ultraviolet emission lines (WLQs), SDSS J114153.34+021924.3 at z = 3.55 and SDSS J123743.08+630144.9 at z = 3.49. In both sources, we detect an unusually weak

  11. Constraints on the Broad Line Region Properties and Extinction in Local Seyferts

    CERN Document Server

    Schnorr-Müller, Allan; 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; de Xivry, G Orban; Riffel, R; Riffel, R A; Schartmann, M; Sternberg, A; Sturm, E; Tacconi, L; Veilleux, S; Ulrich, O A

    2016-01-01

    We use high spectral resolution (R > 8000) data covering 3800-13000\\r{A} to study the physical conditions of the broad line region (BLR) of nine nearby Seyfert 1 galaxies. Up to six broad HI lines are present in each spectrum. A comparison - for the first time using simultaneous optical to near-infrared observations - to photoionisation 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 HI emitting gas of 10$^{11}$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-fit intrinsic broad-line H$\\alpha$/H$\\beta$ ratios being in the range 2.5-6.6 as derived with our photoionization modeling scheme. The extinction to the BLR, based on independent estimates...

  12. Evidence of the Link between Broad Emission Line Regions and Accretion Disks in Active Galactic Nuclei

    Institute of Scientific and Technical Information of China (English)

    Yun Xu; Xin-Wu Cao

    2007-01-01

    There is observational evidence that broad-line regions (BLRs) exist in most active galactic nuclei (AGNs), but their origin is still unclear. One scenario is that the BLRs originate from winds accelerated from the hot coronae of the disks, and the winds are suppressed when the black hole is accreting at low rates. This model predicts a relation between (m) ((m) = (M)/(M)Edd) and the FWHM of broad emission lines. We estimate the central black hole masses for a sample of bright AGNs by using their broadline-widths and optical luminosities. The dimensionless accretion rates (m) = (M)/(M)Edd are derived from the optical continuum luminosities by using two different models: using an empirical relation between the bolometric luminosity Lbol and the optical luminosity ((m) = Lbol/LEdd, a fixed radiative efficiency is adopted); and calculating the optical spectra of accretion disks as a function of (m). We find a significant correlation between the derived (m) and the observed line width of Hβ,FWHM∝ (m)-0.37, which almost overlaps the disk-corona model calculations, if the viscosity α≈ 0.1 - 0.2 is adopted. Our results provide strong evidence for the physical link between the BLRs and accretion disks in AGNs.

  13. Locally Optimally Emitting Clouds and the Variable Broad Emission Line Spectrum of NGC 5548

    Science.gov (United States)

    Korista, Kirk T.; Goad, Michael R.

    2000-06-01

    In recent work Baldwin et al. proposed that in the geometrically extended broad-line regions (BLRs) of quasars and active galactic nuclei, a range in line-emitting gas properties (e.g., density, column density) might exist at each radius and showed that under these conditions the broad emission line spectra of these objects may be dominated by selection effects introduced by the atomic physics and general radiative transfer within the large pool of line-emitting entities. In this picture, the light we see originates in a vast amalgam of emitters but is dominated by those emitters best able to reprocess the incident continuum into a particular emission line. We test this ``locally optimally emitting clouds'' (LOC) model against the extensive spectroscopic database of the Seyfert 1 galaxy NGC 5548. The time-averaged, integrated-light UV broad emission line spectrum from the 1993 Hubble Space Telescope (HST) monitoring campaign is reproduced via the optimization of three global geometric parameters: the outer radius, the index controlling the radial cloud covering fraction of the continuum source, and the integrated cloud covering fraction. We make an ad hoc selection from the range of successful models, and for a simple spherical BLR geometry we simulate the emission-line light curves for the 1989 IUE and 1993 HST campaigns, using the respective observed UV continuum light curves as drivers. We find good agreement between the predicted and observed light curves and lags-a demonstration of the LOC picture's viability as a means to understanding the BLR environment. Finally, we discuss the next step in developing the LOC picture, which involves the marriage of echo-mapping techniques with spectral simulation grids such as those presented here, using the constraints provided by a high-quality, temporally well-sampled spectroscopic data set.

  14. Evidence for two spatially separated UV continuum emitting regions in the Cloverleaf broad absorption line quasar

    CERN Document Server

    Sluse, D; Anguita, T; Braibant, L; Riaud, P

    2015-01-01

    Testing the standard Shakura-Sunyaev model of accretion is a challenging task because the central region of quasars where accretion takes place is unresolved with telescopes. The analysis of microlensing in gravitationally lensed quasars is one of the few techniques which can test this model, yielding to the measurement of the size and of the temperature profile of the accretion disc. We present spectroscopic observations of the gravitationally lensed broad absorption line quasar H1413+117, which reveal partial microlensing of the continuum emission that appears to originate from two separated regions, a microlensed region corresponding the compact accretion disc, and a non-microlensed region, more extended and contributing to at least 30\\% of the total UV-continuum flux. Because this extended continuum is occulted by the broad absorption line clouds, it is not associated to the host galaxy, but rather to light scattered in the neighbourhood of the central engine. We measure the amplitude of microlensing of t...

  15. Broad Absorption Line Variability in Repeat Quasar Observations from the Sloan Digital Sky Survey

    CERN Document Server

    Lundgren, B F; Brunner, R J; Hall, P B; Schneider, D P; York, D G; Vanden Berk, D E; Brinkmann, J; Lundgren, Britt F.; Wilhite, Brian C.; Brunner, Robert J.; Hall, Patrick B.; Schneider, Donald P.; York, Donald G.; Berk, Daniel E. Vanden; Brinkmann, Jonathan

    2006-01-01

    We present a time-variability analysis of 29 broad absorption line quasars (BALQSOs) observed in two epochs by the Sloan Digital Sky Survey (SDSS). These spectra are selected from a larger sample of BALQSOs with multiple observations by virtue of exhibiting a broad CIV $\\lambda$1549 absorption trough separated from the rest frame of the associated emission peak by more than 3600 km s$^{-1}$. Detached troughs facilitate higher precision variability measurements, since the measurement of the absorption in these objects is not complicated by variation in the emission line flux. We have undertaken a statistical analysis of these detached-trough BALQSO spectra to explore the relationships between BAL features that are seen to vary and the dynamics of emission from the quasar central engine. We have measured variability within our sample, which includes three strongly variable BALs. We have also verified that the statistical behavior of the overall sample agrees with current model predictions and previous studies o...

  16. Observing broad-absorption line quasars with Spectrum-Rontgen-Gamma

    DEFF Research Database (Denmark)

    Singh, K.P.; Schnopper, H.W.; Westergaard, Niels Jørgen Stenfeldt

    1998-01-01

    Broad-absorption line quasars are found to have extremely weak soft X-ray emission when compared with other optically selected quasars. In the only example of PHL 5200 for which a detailed X-ray spectrum has been obtained with ASCA, strong absorption in the source appears to be responsible for the...... lack of soft Xray emission. Broad-band X-ray observations of a sample of BAL QSOs are proposed with a high throughput mission SPECTRUM-RONTGEN-GAMMA (SRG), to find out whether these sources are intrinsically weak over the entire bandwidth of X-rays or only in the soft X-rays due to absorption resulting...... from the line of sight passing through large column density clouds. Simultaneous UV observations will help to constrain the ionization state of the absorbers, and also improve the overall UV to X-ray continuum measurements in them....

  17. The VLBI structure of radio-loud Broad Absorption Line quasars

    Science.gov (United States)

    Liu, Y.; Jiang, D. R.; Gu, M.

    2016-02-01

    The nature and origin of Broad Absorption Line (BAL) quasars and their relationship to non-BAL quasars are an open question. The BAL quasars are probably normal quasars seen along a particular line of sight. Alternatively, they are young or recently refueled. The high resolution radio morphology of BAL quasars is very important to understand the radio properties of BAL quasars. We present VLBA observations at L and C bands for a sample of BAL quasars. The observations will help us to explore the VLBI radio properties, and distinguish the present models of explaining BAL phenomena.

  18. Broad absorption line (BAL) quasars as a class of low luminosity AGNs

    OpenAIRE

    Kunert-Bajraszewska, M.; Ceglowski, M.; Roskowinski, C.; Gawronski, M.

    2015-01-01

    Broad absorption lines seen in some quasars prove the existence of ionized plasma outflows from the accretion disk. Outflows together with powerful jets are important feedback processes. Understanding physics behind BAL outflows might be a key to comprehend Galaxy Evolution as a whole. First radio-loud BAL quasar was discovered in 1997 and this discovery has opened new possibilities for studies of the BAL phenomena, this time on the basis of radio emission. However, information about the radi...

  19. GMRT radio detection of broad lined Type Ic supernova ASASSN-16fp

    Science.gov (United States)

    Nayana, A. J.; Chandra, Poonam

    2016-06-01

    We observed broad lined Type Ic supernova ASASSN-16fp (ATel #9086, #9124, #9128, #9134) with the Giant Metrewave Radio Telescope (GMRT) on 2016 June 29.00 UT in 1390 MHz band. We clearly detect radio emission from the supernova position. The flux density of the supernova in this band is 252+/-74 uJy. More observations are planned. We thanks GMRT staff for carrying out the observations.

  20. Are Seyfert 2 Galaxies without Polarized Broad Emission Lines More Obscured?

    Institute of Scientific and Technical Information of China (English)

    Xin-Wen Shu; Jun-Xian Wang; Peng Jiang

    2008-01-01

    New XMM-Newton data of seven Seyfert 2 galaxies with optical spectropolarimet- ric observations are presented. An analysis of the 0.5 - 10 keV spectra shows that four Seyfert 2 galaxies with polarized broad lines (PBLs) are absorbed by NH < 1024 cm-2, while two of three Seyfert 2 galaxies without PBLs show evidence of Compton-thick obscuration, support- ing the conclusion that Seyfert 2 galaxies without PBLs are more obscured than those with PBLs. Adding the measured obscuration indicators (NH, T ratio, and Fe Kα line EW) of six luminous AGNs to our previous sample improves the significance level of the difference in absorption from 92.3% to 96.3% for NH, 99.1% to 99.4% for T ratio, and 95.3% to 97.4% for Fe Kα line EW. The present results support and enhance the suggestions that the absence of PBLs in Seyfert 2 galaxies can be explained by larger viewing angles of the line of sight to the putative dusty torus, which leads to the obscuration of the broad-line scattering screen, as expected in the unification model.

  1. The lick AGN monitoring project 2011: Fe II reverberation from the outer broad-line region

    Energy Technology Data Exchange (ETDEWEB)

    Barth, Aaron J.; Cooper, Michael C. [Department of Physics and Astronomy, 4129 Frederick Reines Hall, University of California, Irvine, CA 92697-4575 (United States); Pancoast, Anna; Treu, Tommaso [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Bennert, Vardha N. [Physics Department, California Polytechnic State University, San Luis Obispo, CA 93407 (United States); Brewer, Brendon J. [Department of Statistics, The University of Auckland, Private Bag 92019, Auckland 1142 (New Zealand); Canalizo, Gabriela [Department of Physics and Astronomy, University of California, Riverside, CA 92521 (United States); Filippenko, Alexei V.; Li, Weidong; Cenko, S. Bradley; Clubb, Kelsey I. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Gates, Elinor L. [Lick Observatory, P.O. Box 85, Mount Hamilton, CA 95140 (United States); Greene, Jenny E. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Malkan, Matthew A. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095-1547 (United States); Sand, David J. [Texas Tech University, Physics Department, Box 41051, Lubbock, TX 79409-1051 (United States); Stern, Daniel; Assef, Roberto J. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Boulevard, Pasadena, CA 91109 (United States); Woo, Jong-Hak [Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of); Bae, Hyun-Jin [Department of Astronomy and Center for Galaxy Evolution Research, Yonsei University, Seoul 120-749 (Korea, Republic of); Buehler, Tabitha, E-mail: barth@uci.edu [Department of Physics and Astronomy, N283 ESC, Brigham Young University, Provo, UT 84602-4360 (United States); and others

    2013-06-01

    The prominent broad Fe II emission blends in the spectra of active galactic nuclei have been shown to vary in response to continuum variations, but past attempts to measure the reverberation lag time of the optical Fe II lines have met with only limited success. Here we report the detection of Fe II reverberation in two Seyfert 1 galaxies, NGC 4593 and Mrk 1511, based on data from a program carried out at Lick Observatory in Spring 2011. Light curves for emission lines including Hβ and Fe II were measured by applying a fitting routine to decompose the spectra into several continuum and emission-line components, and we use cross-correlation techniques to determine the reverberation lags of the emission lines relative to V-band light curves. In both cases, the measured lag (τ{sub cen}) of Fe II is longer than that of Hβ, although the inferred lags are somewhat sensitive to the choice of Fe II template used in the fit. For spectral decompositions done using the Fe II template of Véron-Cetty et al., we find τ{sub cen}(Fe II)/τ{sub cen}(Hβ) = 1.9 ± 0.6 in NGC 4593 and 1.5 ± 0.3 in Mrk 1511. The detection of highly correlated variations between Fe II and continuum emission demonstrates that the Fe II emission in these galaxies originates in photoionized gas, located predominantly in the outer portion of the broad-line region.

  2. The Link Between the Hidden Broad Line Region and the Accretion Rate in Seyfert 2 Galaxies

    CERN Document Server

    Marinucci, Andrea; Nicastro, Fabrizio; Matt, Giorgio; Goulding, Andy D

    2012-01-01

    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 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 CaII and Mg b triplets in Seyfert 2 galaxies, to estimate the mass of the central black holes via the Mbh-{\\sigma}\\ast 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 ...

  3. Extreme Ultraviolet Emission Lines of Iron Fe XI-XIII

    Science.gov (United States)

    Lepson, Jaan; Beiersdorfer, P.; Brown, G. V.; Liedahl, D. A.; Brickhouse, N. S.; Dupree, A. K.

    2013-04-01

    The extreme ultraviolet (EUV) spectral region (ca. 20--300 Å) is rich in emission lines from low- to mid-Z ions, particularly from the middle charge states of iron. Many of these emission lines are important diagnostics for astrophysical plasmas, providing information on properties such as elemental abundance, temperature, density, and even magnetic field strength. In recent years, strides have been made to understand the complexity of the atomic levels of the ions that emit the lines that contribute to the richness of the EUV region. Laboratory measurements have been made to verify and benchmark the lines. Here, we present laboratory measurements of Fe XI, Fe XII, and Fe XIII between 40-140 Å. The measurements were made at the Lawrence Livermore electron beam ion trap (EBIT) facility, which has been optimized for laboratory astrophysics, and which allows us to select specific charge states of iron to help line identification. We also present new calculations by the Hebrew University - Lawrence Livermore Atomic Code (HULLAC), which we also utilized for line identification. We found that HULLAC does a creditable job of reproducing the forest of lines we observed in the EBIT spectra, although line positions are in need of adjustment, and line intensities often differed from those observed. We identify or confirm a number of new lines for these charge states. This work was supported by the NASA Solar and Heliospheric Program under Contract NNH10AN31I and the DOE General Plasma Science program. Work was performed in part under the auspices of the Department of Energy by Lawrence Livermore National Laboratory under Contract DEAC52-07NA27344.

  4. Reverberation Mapping of the Broad Line Region: application to a hydrodynamical line-driven disk wind solution

    CERN Document Server

    Waters, Tim; Proga, Daniel; Eracleous, Michael; Barth, Aaron J; Greene, Jenny

    2016-01-01

    The latest analysis efforts in reverberation mapping are beginning to allow reconstruction of echo images (or velocity-delay maps) that encode information about the structure and kinematics of the broad line region (BLR) in active galactic nuclei (AGNs). Such maps can constrain sophisticated physical models for the BLR. The physical picture of the BLR is often theorized to be a photoionized wind launched from the AGN accretion disk. Previously we showed that the line-driven disk wind solution found in an earlier simulation by Proga and Kallman is virialized over a large distance from the disk. This finding implies that, according to this model, black hole masses can be reliably estimated through reverberation mapping techniques. However, predictions of echo images expected from line-driven disk winds are not available. Here, after presenting the necessary radiative transfer methodology, we carry out the first calculations of such predictions. We find that the echo images are quite similar to other virialized ...

  5. Broad-line region kinematics and black hole mass in Markarian 6

    Science.gov (United States)

    Doroshenko, V. T.; Sergeev, S. G.; Klimanov, S. A.; Pronik, V. I.; Efimov, Yu. S.

    2012-10-01

    We present the results of optical spectral and photometric observations of the nucleus of Markarian 6 made with the 2.6-m Shajn telescope at the Crimean Astrophysical Observatory. The continuum and emission Balmer-line intensities varied by more than a factor of two during 1992-2008. The lag between the continuum and Hβ emission-line flux variations is 21.1 ± 1.9 days. For the Hα line the lag is about 27 days, but its uncertainty is much larger. We use Monte Carlo simulations of random time series to check the effect of our data sampling on the lag uncertainties and we compare our simulation results with those obtained by the random subset selection (RSS) method of Peterson et al. The lags in the high-velocity wings are shorter than those in the line core in accordance with virial motion. However, the lag is slightly larger in the blue wing than in the red wing. This is a signature of infall gas motion. Probably the broad-line region kinematic in the Mrk 6 nucleus is a combination of Keplerian and infall motions. The velocity-delay dependence is similar for individual observational seasons. Measurements of the Hβ line width in combination with the reverberation lag permit us to determine the black hole mass, MBH = (1.8 ± 0.2) × 108 M⊙. This result is consistent with active galactic nucleus scaling relationships between the broad-line region radius and the optical continuum luminosity (RBLR ∝ L0.5) as well as with the black hole mass-luminosity relationship (MBH-L) under an Eddington luminosity ratio for Mrk 6 of Lbol/LEdd ˜ 0.01.

  6. Chemical Abundances in Broad Emission Line Regions The "Nitrogen-Loud" QSO 0353-383

    CERN Document Server

    Baldwin, J A; Korista, K T; Ferland, G J; Dietrich, M; Warner, C

    2003-01-01

    The intensity of the strong N V 1240 line relative to C IV 1549 or to He II 1640 has been proposed as an indicator of the metallicity of QSO broad emission line regions, allowing abundance measurements in a large number of QSOs out to the highest redshifts. Previously, it had been shown that the (normally) much weaker lines N III] 1750 and N IV] 1486 could be used in the same way. The redshift 1.96 QSO 0353-383 has long been known to have N III] and N IV] lines that are far stronger relative to Ly-alpha or C IV than in any other QSO. Because in this particular case these intercombination lines can be easily measured, this unusual object provides an ideal opportunity for testing whether the N V line is a valid abundance indicator. Using new observations of Q0353-383 made both with HST in the ultraviolet and from the ground in the visible passband, we find that intensity ratios involving the strengths of N V, N IV] and N III] relative to lines of He, C and O all indicate that nitrogen is overabundant relative t...

  7. Interpreting broad emission-line variations - II. Tensions between luminosity, characteristic size, and responsivity

    Science.gov (United States)

    Goad, M. R.; Korista, K. T.

    2015-11-01

    We investigate the variability behaviour of the broad H β emission-line to driving continuum variations in the best-studied AGN NGC 5548. For a particular choice of broad emission-line region (BLR) geometry, H β surface emissivity based on photoionization models, and using a scaled version of the 13-yr optical continuum light-curve as a proxy for the driving ionizing continuum, we explore several key factors that determine the broad emission-line luminosity L, characteristic size RRW, and variability amplitude (i.e. responsivity) η, as well as the interplay between them. For fixed boundary models which extend as far as the hot dust the predicted delays for H β are on average too long. However, the predicted variability amplitude of H β provides a remarkably good match to observations except during low-continuum states. We suggest that the continuum flux variations which drive the redistribution in H β surface emissivity F(r) do not on their own lead to large enough changes in RRW or ηeff. We thus investigate dust-bounded BLRs for which the location of the effective outer boundary is modulated by the continuum level and the dust-sublimation and dust-condensation time-scales. We find that in order to match the observed variability amplitude of broad H β in NGC 5548 a rather static outer boundary is preferred. Intriguingly, we show that the most effective way of reducing the H β delay, while preserving its responsivity and equivalent width, is to invoke a smaller value in the incident ionizing photon flux ΦH for a given ionizing source-cloud radial distance r, than is normally inferred from the observed UV continuum flux and typical models of the continuum spectral energy distribution.

  8. The Sloan Digital Sky Survey Reverberation Mapping Project: Ensemble Spectroscopic Variability of Quasar Broad Emission Lines

    CERN Document Server

    Sun, Mouyuan; Shen, Yue; Brandt, W N; Dawson, Kyle; Denney, Kelly D; Hall, Patrick B; Ho, Luis C; Horne, Keith; Jiang, Linhua; Richards, Gordon T; Schneider, Donald P; Bizyaev, Dmitry; Kinemuchi, Karen; Oravetz, Daniel; Pan, Kaike; Simmons, Audrey

    2015-01-01

    We explore the variability of quasars in the MgII and Hbeta broad emission lines and UV/optical continuum emission using the Sloan Digital Sky Survey Reverberation Mapping project (SDSS-RM). This is the largest spectroscopic study of quasar variability to date: our study includes 29 spectroscopic epochs from SDSS-RM over $6$ months, containing 357 quasars with MgII and 41 quasars with Hbeta . On longer timescales, the study is also supplemented with two-epoch data from SDSS-I/II. The SDSS-I/II data include an additional $2854$ quasars with MgII and 572 quasars with Hbeta. The MgII emission line is significantly variable ($\\Delta f/f$ 10% on 100-day timescales), indicating that it is feasible to use the broad MgII line for reverberation mapping studies. The data also confirm that continuum variability increases with timescale and decreases with luminosity, and the continuum light curves are consistent with a damped random-walk model on rest-frame timescales of $\\gtrsim 5$ days. We compare the emission-line and...

  9. On the accuracy of Black Hole Mass estimation from Broad Emission Lines

    Science.gov (United States)

    Mejia-Restrepo, Julian; Trakhtenbrot, Benny; Lira, Paulina; Netzer, Hagai; Capellupo, Daniel

    2016-08-01

    In this talk we compare single-epoch (SE) black hole mass (MBH) estimates based on low ionization (Hα, Hβ, and MgII) and high ionization (CIV) broad emission lines. We also examine the implications of different continuum modeling approaches in line width and MBH measurements. For this purpose we use a sample of 39 unobscured AGNs at z=1.55 selected to cover a large range in MBH (2.0dex) and L/Ledd (2.5dex) and observed by X-shooter. We find that using a local power-law continuum instead of a physically-motivated thin disk continuum leads to only slight underestimation of the FWHM of the lines and the associated MBH(FWHM). However, the line dispersion σ and associated MBH(σ) are strongly affected by the continuum placement providing less reliable mass estimates. We find that low ionization lines provides reliable virial MBH estimation. However, the CIV line is not reliable in the majority of the cases, indicating that the gas emitting this line may not be virialized. We find that Hα, Hβ show similar line widths and that FWHM(MgII) is about 30% narrower than FWHM(Hβ) . We test and confirm several recent suggestions to improve the accuracy in CIV-based mass estimates, relying on other UV emission lines. However, we find that such improvements do not help in reducing the scatter between CIV-based and Balmer-line-based mass estimates. This work has been recently accepted for publication in MNRAS.

  10. The Sloan Digital Sky Survey Reverberation Mapping Project: Rapid CIV Broad Absorption Line Variability

    CERN Document Server

    Grier, C J; Brandt, W N; Trump, J R; Shen, Yue; Vivek, M; Ak, N Filiz; Chen, Yuguang; Dawson, K; Denney, K D; Jiang, Linhua; Kochanek, C S; McGreer, Ian D; Pâris, I; Peterson, B M; Schneider, D P; Tao, Charling; Wood-Vasey, W M; Bizyaev, Dmitry; Ge, Jian; Kinemuchi, Karen; Oravetz, Daniel; Pan, Kaike; Simmons, Audrey

    2015-01-01

    We report the discovery of rapid variations of a high-velocity CIV broad absorption line trough in the quasar SDSS J141007.74+541203.3. This object was intensively observed in 2014 as a part of the Sloan Digital Sky Survey Reverberation Mapping Project, during which 32 epochs of spectroscopy were obtained with the Baryon Oscillation Spectroscopic Survey spectrograph. We observe significant (>4sigma) variability in the equivalent width of the broad (~4000 km/s wide) CIV trough on rest-frame timescales as short as 1.20 days (~29 hours), the shortest broad absorption line variability timescale yet reported. The equivalent width varied by ~10% on these short timescales, and by about a factor of two over the duration of the campaign. We evaluate several potential causes of the variability, concluding that the most likely cause is a rapid response to changes in the incident ionizing continuum. If the outflow is at a radius where the recombination rate is higher than the ionization rate, the timescale of variability...

  11. Reverberation Mapping of the Broad Line Region: Application to a Hydrodynamical Line-driven Disk Wind Solution

    Science.gov (United States)

    Waters, Tim; Kashi, Amit; Proga, Daniel; Eracleous, Michael; Barth, Aaron J.; Greene, Jenny

    2016-08-01

    The latest analysis efforts in reverberation mapping are beginning to allow reconstruction of echo images (or velocity-delay maps) that encode information about the structure and kinematics of the broad line region (BLR) in active galactic nuclei (AGNs). Such maps can constrain sophisticated physical models for the BLR. The physical picture of the BLR is often theorized to be a photoionized wind launched from the AGN accretion disk. Previously we showed that the line-driven disk wind solution found in an earlier simulation by Proga and Kallman is virialized over a large distance from the disk. This finding implies that, according to this model, black hole masses can be reliably estimated through reverberation mapping techniques. However, predictions of echo images expected from line-driven disk winds are not available. Here, after presenting the necessary radiative transfer methodology, we carry out the first calculations of such predictions. We find that the echo images are quite similar to other virialized BLR models such as randomly orbiting clouds and thin Keplerian disks. We conduct a parameter survey exploring how echo images, line profiles, and transfer functions depend on both the inclination angle and the line opacity. We find that the line profiles are almost always single peaked, while transfer functions tend to have tails extending to large time delays. The outflow, despite being primarily equatorially directed, causes an appreciable blueshifted excess on both the echo image and line profile when seen from lower inclinations (i≲ 45^\\circ ). This effect may be observable in low ionization lines such as {{H}}β .

  12. Iron line profiles in Suzaku spectra of bare Seyfert galaxies

    CERN Document Server

    Patrick, A R; Porquet, D; Markowitz, A G; Lobban, A P; Terashima, Y

    2010-01-01

    We methodically model the broad-band Suzaku spectra of a small sample of six 'bare' Seyfert galaxies: Ark 120, Fairall 9, MCG-02-14-009, Mrk 335, NGC 7469 and SWIFT J2127.4+5654. The analysis of bare Seyferts allows a consistent and physical modelling of AGN due to a weak amount of any intrinsic warm absorption, removing the degeneracy between the spectral curvature due to warm absorption and the red-wing of the Fe K region. Through effective modelling of the broad-band spectrum and investigating the presence of narrow neutral or ionized emission lines and reflection from distant material, we obtain an accurate and detailed description of the Fe K line region using models such as laor, kerrdisk and kerrconv. Results suggest that ionized emission lines at 6.7 keV and 6.97 keV (particularly Fe XXVI) are relatively common and the inclusion of these lines can greatly affect the parameters obtained with relativistic models i.e. spin, emissivity, inner radius of emission and inclination. Moderately broad components...

  13. Disentangling the circumnuclear environs of Centaurus A: II. On the nature of the broad absorption line

    CERN Document Server

    Espada, D; Matsushita, S; Sakamoto, K; Henkel, C; Iono, D; Israel, F P; Muller, S; Petitpas, G; Pihlstroem, Y; Taylor, G B; Trung, D V

    2010-01-01

    We report on atomic gas (HI) and molecular gas (as traced by CO(2-1)) redshifted absorption features toward the nuclear regions of the closest powerful radio galaxy, Centaurus A (NGC 5128). Our HI observations using the Very Long Baseline Array allow us to discern with unprecedented sub-parsec resolution HI absorption profiles toward different positions along the 21 cm continuum jet emission in the inner 0."3 (or 5.4 pc). In addition, our CO(2-1) data obtained with the Submillimeter Array probe the bulk of the absorbing molecular gas with little contamination by emission, not possible with previous CO single-dish observations. We shed light with these data on the physical properties of the gas in the line of sight, emphasizing the still open debate about the nature of the gas that produces the broad absorption line (~55 km/s). First, the broad H I line is more prominent toward the central and brightest 21 cm continuum component than toward a region along the jet at a distance ~ 20 mas (or 0.4 pc) further from...

  14. Estimation of relativistic accretion disk parameters from iron line emission

    CERN Document Server

    Pariev, V I; Miller, W A; Pariev, Vladimir I.; Bromley, Benjamin C.; Miller, Warner A.

    2000-01-01

    The observed iron K-alpha fluorescence lines in Seyfert-1 galaxies provide strong evidence for an accretion disk near a supermassive black hole as a source of the emission. Here we present an analysis of the geometrical and kinematic properties of the disk based on the extreme frequency shifts of a line profile as determined by measurable flux in both the red and blue wings. The edges of the line are insensitive to the distribution of the X-ray flux over the disk, and hence provide a robust alternative to profile fitting of disk parameters. Our approach yields new, strong bounds on the inclination angle of the disk and the location of the emitting region. We apply our method to interpret observational data from MCG-6-30-15 and find that the commonly assumed inclination 30 deg for the accretion disk in MCG-6-30-15 is inconsistent with the position of the blue edge of the line at a 3 sigma level. A thick turbulent disk model or the presence of highly ionized iron may reconcile the bounds on inclination from the...

  15. Probing the Inner Structure of Polar Broad Absorption-Line Quasars

    Science.gov (United States)

    Ghosh, Kajal

    2008-10-01

    We have discovered a sample of polar broad absorption-line quasars (BALQSOs). We know their inclination angles with reasonable certainty. Thus, these are the ideal objects to probe their inner structure through the X-ray studies. However, to date, we do not have a reasonably good signal-to-noise ratio X-ray spectrum of any of these objects. Here, we propose deep XMM-Newton observations of four polar BALQSOs to study the physical processes responsible for the X-ray emission, distribution of BAL clouds, wind driven mechanism, jet entrainment, etc. Finally, all these results will be used to constrain our time-dependent hydrodynamical simulations.

  16. Evidence for Broad-Line Region Outflows and Their Impact on Black Hole Mass Measurements

    DEFF Research Database (Denmark)

    Denney, K. D.; Assef, R. J.; Horne, K.;

    2012-01-01

    could not be fully and accurately interpreted from the 1D velocity-resolved reverberation signal. From the VDM, an outflow component to the emission remains possible but appears to be in addition to an underlying, disk-like BLR structure consistent in size with the measured reverberation lag. The black...... hole (BH) mass derived from this data is therefore secure from any uncertainties possibly derived from gravitationally unbound gas contributing to the emission. Additionally, we demonstrate that BLR emission from the C IV ¿1549 broad emission line can reliably be used as a virial BH mass estimator...

  17. Simulations of the Broad Line Region of NGC 5548 with Cloudy Code: Temperature Determination

    Science.gov (United States)

    Ilic, D.

    2007-12-01

    In this paper an analysis of the physical properties of the Broad Line Region (BLR) of the active galaxy NGC 5548 is presented. Using the photoionization code CLOUDY and the measurements of Peterson et al. (2002), the physical conditions of the BLR are simulated and the BLR temperature is obtained. This temperature was compared to the temperature estimated with the Boltzmann-Plot (BP) method (Popović et al. 2007). It was shown that the measured variability in the BLR temperature could be due to the change in the hydrogen density.

  18. The relationship of extended radio power and broad emission line luminosity in blazars

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The relationship between broad line luminosity LBLR and extended radio power PE is investigated.In the log PE-log LBLR diagram,FSRQs populate the region of higher luminosity relative to BL Lacs,and FR II BL Lacs are between FSRQs and FR I BL Lacs.For these blazars,there is a significant correlation between LBLR and PE.The regression line scales as PE ∝ L0B.L87R ± 0.15.The slope of this scaling relation is consistent with that derived from the simple theoretical formulae.Thus,the unification of BL Lacs and FRSQs into a single population finds a statistical basis,and a disk-jet symbiosis in blazars is confirmed.FR II BL Lacs are probably at an intermediate stage in the sequence from FSRQs to BL Lacs with FR I BL Lacs at the end of this sequence.

  19. Test of the Formation mechanism of the Broad Line Region in Active Galactic Nuclei

    CERN Document Server

    Czerny, Bozena; Wang, Jian-Min; Karas, Vladimir

    2016-01-01

    The origin of the Broad Line Region (BLR) in active galaxies remains unknown. It seems to be related to the underlying accretion disk but an efficient mechanism is required to rise the material from the disk surface without giving too strong signatures of the outflow in the case of the low ionization lines. We discuss in detail two proposed mechanisms: (i) radiation pressure acting on dust in the disk atmosphere creating a failed wind (ii) the gravitational instability of the underlying disk. We compare the predicted location of the inner radius of the BLR in those two scenarios with the observed position obtained from the reverberation studies of several active galaxies. The failed dusty outflow model well represents the observational data while the predictions of the self-gravitational instability are not consistent with observations. The issue remains why actually we do not see any imprints of the underlying disk instability in the BLR properties.

  20. REVERBERATION AND PHOTOIONIZATION ESTIMATES OF THE BROAD-LINE REGION RADIUS IN LOW-z QUASARS

    Energy Technology Data Exchange (ETDEWEB)

    Negrete, C. Alenka [Instituto Nacional de Astrofisica, Optica y Electronica (Mexico); Dultzin, Deborah [Instituto de Astronomia, Universidad Nacional Autonoma de Mexico (Mexico); Marziani, Paola [INAF, Astronomical Observatory of Padova, I-35122 Padova (Italy); Sulentic, Jack W., E-mail: cnegrete@inaoep.mx, E-mail: deborah@astro.unam.mx, E-mail: paola.marziani@oapd.inaf.it, E-mail: sulentic@iaa.es [Instituto de Astrofisica de Andalucia, E-18008 Granada (Spain)

    2013-07-01

    Black hole mass estimation in quasars, especially at high redshift, involves the use of single-epoch spectra with signal-to-noise ratio and resolution that permit accurate measurement of the width of a broad line assumed to be a reliable virial estimator. Coupled with an estimate of the radius of the broad-line region (BLR) this yields the black hole mass M{sub BH}. The radius of the BLR may be inferred from an extrapolation of the correlation between source luminosity and reverberation-derived r{sub BLR} measures (the so-called Kaspi relation involving about 60 low-z sources). We are exploring a different method for estimating r{sub BLR} directly from inferred physical conditions in the BLR of each source. We report here on a comparison of r{sub BLR} estimates that come from our method and from reverberation mapping. Our ''photoionization'' method employs diagnostic line intensity ratios in the rest-frame range 1400-2000 A (Al III {lambda}1860/Si III] {lambda}1892, C IV {lambda}1549/Al III {lambda}1860) that enable derivation of the product of density and ionization parameter with the BLR distance derived from the definition of the ionization parameter. We find good agreement between our estimates of the density, ionization parameter, and r{sub BLR} and those from reverberation mapping. We suggest empirical corrections to improve the agreement between individual photoionization-derived r{sub BLR} values and those obtained from reverberation mapping. The results in this paper can be exploited to estimate M{sub BH} for large samples of high-z quasars using an appropriate virial broadening estimator. We show that the width of the UV intermediate emission lines are consistent with the width of H{beta}, thereby providing a reliable virial broadening estimator that can be measured in large samples of high-z quasars.

  1. Estimating Black Hole Masses in Quasars Using Broad Optical and UV Emission Lines

    CERN Document Server

    Marziani, Paola

    2011-01-01

    We review past work using broad emission lines as virial estimators of black hole masses in quasars. Basically one requires estimates of the emitting region radius and virial velocity dispersion to obtain black hole masses. The three major ways to estimate the broad-line emitting region (BLR) radius involve: (1) direct reverberation mapping, (2) derivation of BLR radius for larger samples using the radius-luminosity correlation derived from reverberation measures, and (3) estimates of BLR radius using the definition of the ionization parameter solved for BLR radius (photoionization method). At low redshift (z < 0.7) FWHM H-beta serves as the most widely used estimator of virial velocity dispersion. FWHM H-beta can provide estimates for tens of thousands of quasars out to z ~ 3.8 (IR spectroscopy beyond z ~ 1). A new photoionization method also shows promise for providing many reasonable estimates of BLR radius via high S/N IR spectroscopy of the UV region 1300 -- 2000 A. FWHM MgII 2800 can serve as a surro...

  2. Interpreting broad emission-line variations II: Tensions between luminosity, characteristic size and responsivity

    CERN Document Server

    Goad, Michael R

    2015-01-01

    We investigate the variability behaviour of the broad Hb emission-line to driving continuum variations in the best-studied AGN NGC 5548. For a particular choice of BLR geometry, Hb surface emissivity based on photoionization models, and using a scaled version of the 13 yr optical continuum light curve as a proxy for the driving ionizing continuum, we explore several key factors that determine the broad emission line luminosity L, characteristic size R(RW), and variability amplitude (i.e., responsivity) eta, as well as the interplay between them. For fixed boundary models which extend as far as the hot-dust the predicted delays for Hb are on average too long. However, the predicted variability amplitude of Hb provides a remarkably good match to observations except during low continuum states. We suggest that the continuum flux variations which drive the redistribution in Hb surface emissivity F(r) do not on their own lead to large enough changes in R(RW) or eta(eff). We thus investigate dust-bounded BLRs for w...

  3. Effect of the drag force on the orbital motion of the broad-line region clouds

    CERN Document Server

    Khajenabi, Fazeleh

    2016-01-01

    We investigate orbital motion of cold clouds in the broad line region of active galactic nuclei subject to the gravity of a black hole and a force due to a nonisotropic central source and a drag force proportional to the velocity square. The intercloud is described using the standard solutions for the advection-dominated accretion flows. Orbit of a cloud decays because of the drag force, but the typical time scale of falling of clouds onto the central black hole is shorter comparing to the linear drag case. This time scale is calculated when a cloud is moving through a static or rotating intercloud. We show that when the drag force is a quadratic function of the velocity, irrespective of the initial conditions and other input parameters, clouds will generally fall onto the central region much faster than the age of whole system and since cold clouds present in most of the broad line regions, we suggest that mechanisms for continuous creation of the clouds must operate in these systems.

  4. SN2003bg: a broad-lined Type IIb Supernova with Hydrogen

    CERN Document Server

    Mazzali, Paolo A; Hamuy, Mario; Nomoto, Ken'ichi

    2009-01-01

    Models for the spectra and the light curve, in the photospheric as well as in the late nebular phase, are used to infer the properties of the very radio-bright, broad-lined type IIb Supernova 2003bg. Consistent fits to the light curve and the spectral evolution are obtained with an explosion that ejected ~ 4 M_sun of material with a kinetic energy of ~ 5 10^51 erg. A thin layer of hydrogen, comprising ~ 0.05 M_sun, is inferred to be present in the ejecta at the highest velocities (v >~ 9000 km/s), while a thicker helium layer, comprising ~ 1.25 M_sun, was ejected at velocities between 6500 and 9000 km/s. At lower velocities, heavier elements are present, including ~ 0.2 M_sun of 56Ni that shape the light curve and the late-time nebular spectra. These values suggest that the progenitor star had a mass of ~ 20-25 M_sun (comparable to, but maybe somewhat smaller than that of the progenitor of the XRF/SN 2008D). The rather broad-lined early spectra are the result of the presence of a small amount of material (~ 0...

  5. Magnetically elevated accretion disks in active galactic nuclei: broad emission line regions and associated star formation

    Science.gov (United States)

    Begelman, Mitchell C.; Silk, Joseph

    2016-10-01

    We propose that the accretion disks fueling active galactic nuclei are supported vertically against gravity by a strong toroidal (φ -direction) magnetic field that develops naturally as the result of an accretion disk dynamo. The magnetic pressure elevates most of the gas carrying the accretion flow at R to large heights z ˜ 0.1 R and low densities, while leaving a thin dense layer containing most of the mass - but contributing very little accretion - around the equator. We show that such a disk model leads naturally to the formation of a broad emission line region through thermal instability. Extrapolating to larger radii, we demonstrate that local gravitational instability and associated star formation are strongly suppressed compared to standard disk models for AGN, although star formation in the equatorial zone is predicted for sufficiently high mass supply rates. This new class of accretion disk models thus appears capable of resolving two longstanding puzzles in the theory of AGN fueling: the formation of broad emission line regions and the suppression of fragmentation thought to inhibit accretion at the required rates. We show that the disk of stars that formed in the Galactic Center a few million years ago could have resulted from an episode of magnetically elevated accretion at ˜0.1 of the Eddington limit.

  6. A Catalog of Broad Absorption Line Quasars from the Sloan Digital Sky Survey Third Data Release

    CERN Document Server

    Trump, J R; Brinkman, J; Fan, X; Hall, P B; Kleinman, S J; Knapp, G R; Nitta, A; Reichard, T A; Richards, G T; Schneider, D P; Vanden Berk, Daniel E; Anderson, Scott F.; Berk, Daniel E. Vanden; Fan, Xiaohui; Hall, Patrick B.; Knapp, Gillian R.; Nitta, Atsuko; Reichard, Timothy A.; Richards, Gordon T.; Schneider, Donald P.; Trump, Jonathan R.

    2006-01-01

    We present a total of 4784 unique broad absorption line quasars from the Sloan Digital Sky Survey Third Data Release. An automated algorithm was used to match a continuum to each quasar and to identify regions of flux at least 10% below the continuum over a velocity range of at least 1000 km/s in the CIV and MgII absorption regions. The model continuum was selected as the best-fit match from a set of template quasar spectra binned in luminosity, emission line width, and redshift, with the power-law spectral index and amount of dust reddening as additional free parameters. We characterize our sample through the traditional ``balnicity'' index and a revised absorption index, as well as through parameters such as the width, outflow velocity, fractional depth and number of troughs. From a sample of 16883 quasars at 1.7 \\le z \\le 4.38, we identify 4386 (26.0%) quasars with broad CIV absorption, of which 1756 (10.4%) satisfy traditional selection criteria. From a sample of 34973 quasars at 0.5 \\le z \\le 2.15, we id...

  7. Marketing the `Broad Line': Invitations to STEM education in a Swedish recruitment campaign

    Science.gov (United States)

    Andrée, Maria; Hansson, Lena

    2013-01-01

    In many Western societies, there is a concern about the tendency of young people not choosing Science, Technology, Engineering, and Mathematics (STEM) education and occupations. In response, different initiatives have been launched. If one believes that science should have a place in more young people's lives, an important question is to what extent recruitment campaigns communicate messages that open up for STEM education to become relevant in young people's identity formation. Here, we analyse a Swedish government-initiated, primarily Internet-based recruitment attempt ('The Broad Line Campaign') aimed at increasing the number of young people choosing the natural science programme in upper secondary school. The campaign is based on marketing principles and deliberately draws on identity issues. The data analysed consists of campaign films and written resources describing the campaign. Data are analysed by use of the constant comparative approach in order to produce categories describing different messages about why to engage in STEM education. These messages are then analysed from an identity perspective using the concept of subjective values. Our results show that the messages communicated in the Broad Line campaign emphasise utility value, attainment value and relative cost rather than interest-enjoyment. The campaign communicates that the natural science programme is to be associated with a high attainment value without establishing relations to the field of science. Finally, potential consequences of the communicated messages in the campaign are discussed in light of previous research.

  8. Elemental Abundances in the Broad Emission Line Region of Quasars at Redshifts larger than 4

    CERN Document Server

    Dietrich, M; Hamann, F; Heidt, J; Jäger, K; Vestergaard, M; Wagner, S J

    2003-01-01

    We present observations of 11 high redshift quasars ($3.9 \\la z \\la 5.0$) observed with low spectral resolution in the restframe ultraviolet using FORS 1 at the VLT UT 1. The emission-line fluxes of strong permitted and intercombination ultraviolet emission lines are measured to estimate the chemical composition of the line emitting gas. Comparisons to photoionization calculations indicate gas metallicities in the broad emission line region in the range of solar to several times solar. The average of the mean metallicity of each high-z quasar in this sample is $Z/Z_\\odot = 4.3 \\pm 0.3$. Assuming a chemical evolution time scale of $\\tau_{evol} \\simeq 0.5 - 0.8$ Gyrs, we derive a redshift of $z_f \\simeq 6 {\\rm to} 8$ for the onset of the first major star formation episode (H$_o = 65$ km s$^{-1}$ Mpc$^{-1}$, $\\Omega_M = 0.3$, $\\Omega_\\Lambda = 0.7$), corresponding to an age of the universe of several $10^8$ yrs at this epoch. We note that this epoch is also supposed to be the era of re-ionization of the universe...

  9. The Importance of Broad Emission-Line Widths in Single Epoch Black Hole Mass Estimates

    CERN Document Server

    Assef, R J; Grier, C J; Kochanek, C S; Denney, K D; Peterson, B M

    2012-01-01

    Estimates of the mass of super-massive black holes (BHs) in distant active galactic nuclei (AGNs) can be obtained efficiently only through single-epoch spectra, using a combination of their broad emission-line widths and continuum luminosities. Yet the reliability and accuracy of the method, and the resulting mass estimates, M_BH, remain uncertain. A recent study by Croom using a sample of SDSS, 2QZ and 2SLAQ quasars suggests that line widths contribute little information about the BH mass in these single-epoch estimates and can be replaced by a constant value without significant loss of accuracy. In this Letter, we use a sample of nearby reverberation-mapped AGNs to show that this conclusion is not universally applicable. We use the bulge luminosity (L_Bulge) of these local objects to test how well the known M_BH - L_Bulge correlation is recovered when using randomly assigned line widths instead of the measured ones to estimate M_BH. We find that line widths provide significant information about M_BH, and th...

  10. The HST view of the broad line region in low luminosity AGN

    CERN Document Server

    Balmaverde, B; di Torino, INAF - Osservatorio Astrofisico

    2014-01-01

    We analyze the properties of the broad line region (BLR) in low luminosity AGN by using HST/STIS spectra. We consider a sample of 24 nearby galaxies in which the presence of a BLR has been reported from their Palomar ground-based spectra. Following a widely used strategy, we used the [SII] doublet to subtract the contribution of the narrow emission lines to the H-alpha+[NII] complex and to isolate the BLR emission. Significant residuals that suggest a BLR, are present. However, the results change substantially when the [OI] doublet is used. Furthermore, the spectra are also reproduced well by just including a wing in the narrow H-alpha and [NII] lines, thus not requiring the presence of a BLR. We conclude that complex structure of the narrow line region (NLR) is not captured with this approach and that it does not lead to general robust constraints on the properties of the BLR in these low luminosity AGN. Nonetheless, the existence of a BLR is firmly established in 5 Seyferts, and 5 LINERs. However, the measu...

  11. The Lick AGN Monitoring Project 2011: Fe II Reverberation from the Outer Broad-Line Region

    CERN Document Server

    Barth, Aaron J; Bennert, Vardha N; Brewer, Brendon J; Canalizo, Gabriela; Filippenko, Alexei V; Gates, Elinor L; Greene, Jenny E; Li, Weidong; Malkan, Matthew A; Sand, David J; Stern, Daniel; Treu, Tommaso; Woo, Jong-Hak; Assef, Roberto J; Bae, Hyun-Jin; Buehler, Tabitha; Cenko, S Bradley; Clubb, Kelsey I; Cooper, Michael C; Diamond-Stanic, Aleksandar M; Hoenig, Sebastian F; Joner, Michael D; Laney, C David; Lazarova, Mariana S; Nierenberg, A M; Silverman, Jeffrey M; Tollerud, Erik J; Walsh, Jonelle L

    2013-01-01

    The prominent broad Fe II emission blends in the spectra of active galactic nuclei have been shown to vary in response to continuum variations, but past attempts to measure the reverberation lag time of the optical Fe II lines have met with only limited success. Here we report the detection of Fe II reverberation in two Seyfert 1 galaxies, NGC 4593 and Mrk 1511, based on data from a program carried out at Lick Observatory in Spring 2011. Light curves for emission lines including H-beta and Fe II were measured by applying a fitting routine to decompose the spectra into several continuum and emission-line components, and we use cross-correlation techniques to determine the reverberation lags of the emission lines relative to V-band light curves. In both cases the measured lag (t_cen) of Fe II is longer than that of H-beta, although the inferred lags are somewhat sensitive to the choice of Fe II template used in the fit. For spectral decompositions done using the Fe II template of Veron-Cetty et al. (2004), we f...

  12. Gamma-ray opacity of the anisotropic stratified broad-line regions in blazars

    Science.gov (United States)

    Abolmasov, Pavel; Poutanen, Juri

    2016-09-01

    The GeV-range spectra of blazars are shaped not only by non-thermal emission processes internal to the relativistic jet but also by external pair-production absorption on the thermal emission of the accretion disc and the broad-line region (BLR). For the first time, we compute here the pair-production opacities in the GeV range produced by a realistic BLR accounting for the radial stratification and radiation anisotropy. Using photoionization modelling with the CLOUDY code, we calculate a series of BLR models of different sizes, geometries, cloud densities, column densities and metallicities. The strongest emission features in the model BLR are Lyα and He II Lyα. Contribution of recombination continua is smaller, especially for hydrogen, because Ly continuum is efficiently trapped inside the large optical depth BLR clouds and converted to Lyman emission lines and higher-order recombination continua. The largest effects on the gamma-ray opacity are produced by the BLR geometry and localization of the gamma-ray source. We show that when the gamma-ray source moves further from the central source, all the absorption details move to higher energies and the overall level of absorption drops because of decreasing incidence angles between the gamma-rays and BLR photons. The observed positions of the spectral breaks can be used to measure the geometry and the location of the gamma-ray emitting region relative to the BLR. Strong dependence on geometry means that the soft photons dominating the pair-production opacity may be actually produced by a different population of BLR clouds than the bulk of the observed broad line emission.

  13. THE DIFFERENT NATURE OF SEYFERT 2 GALAXIES WITH AND WITHOUT HIDDEN BROAD-LINE REGIONS

    International Nuclear Information System (INIS)

    We compile a large sample of 120 Seyfert 2 galaxies (Sy2s) which contains 49 hidden broad-line region (HBLR) Sy2s and 71 non-HBLR Sy2s. From the difference in the power sources between two groups, we test whether HBLR Sy2s are dominated by active galactic nuclei (AGNs) and whether non-HBLR Sy2s are dominated by starbursts. We show that (1) HBLR Sy2s have larger accretion rates than non-HBLR Sy2s; (2) HBLR Sy2s have larger [Ne V] λ14.32/[Ne II] λ12.81 and [O IV] λ25.89/[Ne II] λ12.81 line ratios than non-HBLR Sy2s; and (3) HBLR Sy2s have smaller IRAS f60/f25 flux ratios, which show the relative strength of the host galaxy and nuclear emission, than non-HBLR Sy2s. Consequently, we suggest that HBLR Sy2s and non-HBLR Sy2s are AGN dominated and starburst dominated, respectively. In addition, non-HBLR Sy2s can be classified into luminous (L[OIII]>1041 erg s-1) and less luminous (L[OIII] 41 erg s-1) samples, when considering only their obscuration. We suggest that (1) the invisibility of polarized broad lines (PBLs) in the luminous non-HBLR Sy2s depends on the obscuration and (2) the invisibility of PBLs in the less luminous non-HBLR Sy2s depends on the very low Eddington ratio rather than the obscuration.

  14. An extreme, blueshifted iron line profile in the Narrow Line Seyfert 1 PG 1402+261; an edge-on accretion disk or highly ionized absorption?

    OpenAIRE

    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 (FWHM velocity of 110000 km/s) iron K-shell emission line. The line centroid energy at 7.3 keV appears blue-shifted with respect to the iron Kalpha emission band between 6.4-6.97 keV, while the blue-win...

  15. Unveiling the X-ray/UV properties of AGN winds using Broad and mini-Broad Absorption Line Quasars

    Science.gov (United States)

    Giustini, M.

    2015-07-01

    BAL/mini-BALs are observed in the UV spectra of ˜ 20-30% of optically selected AGN as broad absorption troughs blueshifted by several thousands km/s, indicative of powerful nuclear winds. They could be representative of the average AGN if their winds cover only 20-30% of the continuum source, and/or represent an evolutionary state analogous to the high-soft state of BHB, when the jet emission is quenched and strong X-ray absorbing equatorial disk winds are virtually ubiquitous. High-quality, possibly time-resolved X-ray/UV studies are crucial to assess the global amount and 'character' of absorption in BAL/mini-BAL QSOs and to constrain the physical mechanism responsible for the launch and acceleration of their winds, therefore placing them in the broader context of AGN geometry and evolution. I will review here the known X-ray properties of BAL/mini-BAL QSOs, and present new results from a comprehensive X-ray spectral analysis of all the Palomar-Green BAL/mini-BAL QSOs with available XMM-Newton observations, for a total of 51 pointings of 14 different sources. These will include the most recent results from a high-quality simultaneous XMM/HST observational campaign on the mini-BAL QSO PG 1126-041, that unveiled with stunning details the X-ray/UV connection in action in an AGN disk wind through correlated X-ray/UV absorption variability.

  16. Ironline of Kerr black holes with scalar hair

    Science.gov (United States)

    Ni, Yueying; Zhou, Menglei; Cárdenas-Avendaño, Alejandro; Bambi, Cosimo; Herdeiro, Carlos A. R.; Radu, Eugen

    2016-07-01

    Recently, a family of hairy black holes in 4-dimensional Einstein gravity minimally coupled to a complex, massive scalar field was discovered [1]. Besides the mass M and spin angular momentum J, these objects are characterized by a Noether charge Q, measuring the amount of scalar hair, which is not associated to a Gauss law and cannot be measured at spatial infinity. Introducing a dimensionless scalar hair parameter q, ranging from 0 to 1, we recover (a subset of) Kerr black holes for q = 0 and a family of rotating boson stars for q = 1. In the present paper, we explore the possibility of measuring q for astrophysical black holes with current and future X-ray missions. We study the ironline expected in the reflection spectrum of such hairy black holes and we simulate observations with Suzaku and eXTP. As a proof of concept, we point out, by analyzing a sample of hairy black holes, that current observations can already constrain the scalar hair parameter q, because black holes with q close to 1 would have iron lines definitively different from those we observe in the available data. We conclude that a detailed scanning of the full space of solutions, together with data from the future X-ray missions, like eXTP, will be able to put relevant constraints on the astrophysical realization of Kerr black holes with scalar hair.

  17. Discovery of superstrong, fading, iron line emission and double-peaked Balmer lines of the galaxy SDSSJ0952+2143 - the light echo of a huge flare

    CERN Document Server

    Komossa, S; Wang, T; Ajello, M; Ge, J; Greiner, J; Lü, H; Salvato, M; Saxton, R; Shan, H; Xu, D; Yuan, W

    2008-01-01

    We report the discovery of superstrong, fading, high-ionization iron line emission in the galaxy SDSSJ095209.56+214313.3 (SDSSJ0952+2143 hereafter), which must have been caused by an X-ray outburst of large amplitude. SDSSJ0952+2143 is unique in its strong multiwavelength variability; such a broadband emission-line and continuum response has not been observed before. The strong iron line emission is accompanied by unusual Balmer line emission with a broad base, narrow core and double-peaked narrow horns, and strong HeII emission. These lines, while strong in the SDSS spectrum taken in 2005, have faded away significantly in new spectra taken in December 2007. Comparison of SDSS, 2MASS, GALEX and follow-up GROND photometry reveals variability in the NUV, optical and NIR band. Taken together, these unusual observations can be explained by a giant outburst in the EUV--X-ray band, detected even in the optical and NIR. The intense and variable iron, Helium and Balmer lines represent the ``light echo'' of the flare,...

  18. Broad absorption line (BAL) quasars as a class of low luminosity AGNs

    CERN Document Server

    Kunert-Bajraszewska, M; Roskowinski, C; Gawronski, M

    2015-01-01

    Broad absorption lines seen in some quasars prove the existence of ionized plasma outflows from the accretion disk. Outflows together with powerful jets are important feedback processes. Understanding physics behind BAL outflows might be a key to comprehend Galaxy Evolution as a whole. First radio-loud BAL quasar was discovered in 1997 and this discovery has opened new possibilities for studies of the BAL phenomena, this time on the basis of radio emission. However, information about the radio structures, orientation and age of BAL quasars is still very limited due to weak radio emission and small sizes of these objects. Our high-resolution radio survey of a sample of BAL quasars aims to increase our knowledge about these objects. In this article, we present some conclusions arising from our research.

  19. Magnetically elevated accretion disks in active galactic nuclei: broad emission line regions and associated star formation

    CERN Document Server

    Begelman, Mitchell C

    2016-01-01

    We propose that the accretion disks fueling active galactic nuclei are supported vertically against gravity by a strong toroidal ($\\phi-$direction) magnetic field that develops naturally as the result of an accretion disk dynamo. The magnetic pressure elevates most of the gas carrying the accretion flow at $R$ to large heights $z > 0.1 R$ and low densities, while leaving a thin dense layer containing most of the mass --- but contributing very little accretion --- around the equator. We show that such a disk model leads naturally to the formation of a broad emission line region through thermal instability. Extrapolating to larger radii, we demonstrate that local gravitational instability and associated star formation are strongly suppressed compared to standard disk models for AGN, although star formation in the equatorial zone is predicted for sufficiently high mass supply rates. This new class of accretion disk models thus appears capable of resolving two longstanding puzzles in the theory of AGN fueling: th...

  20. Quasar cartography: From black hole to broad-line region scales

    Energy Technology Data Exchange (ETDEWEB)

    Chelouche, Doron [Department of Physics, Faculty of Natural Sciences, University of Haifa, Haifa 31905 (Israel); Zucker, Shay, E-mail: doron@sci.haifa.ac.il, E-mail: shayz@post.tau.ac.il [Department of Geophysical, Atmospheric, and Planetary Sciences, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978 (Israel)

    2013-06-01

    A generalized approach to reverberation mapping (RM) is presented, which is applicable to broad- and narrowband photometric data, as well as to spectroscopic observations. It is based on multivariate correlation analysis techniques and, in its present implementation, is able to identify reverberating signals across the accretion disk and the broad-line region (BLR) of active galactic nuclei (AGNs). Statistical tests are defined to assess the significance of time-delay measurements using this approach, and the limitations of the adopted formalism are discussed. It is shown how additional constraints on some of the parameters of the problem may be incorporated into the analysis thereby leading to improved results. When applied to a sample of 14 Seyfert 1 galaxies having good-quality high-cadence photometric data, accretion disk scales and BLR sizes are simultaneously determined, on a case-by-case basis, in most objects. The BLR scales deduced here are in good agreement with the findings of independent spectroscopic RM campaigns. Implications for the photometric RM of AGN interiors in the era of large surveys are discussed.

  1. Properties of Broad Band Continuum of Narrow Line Seyfert 1 Galaxies

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    We have performed a statistical study of the properties of the broadband continuum of Narrow Line Seyfert 1 galaxies (NLS1s) by collecting ratio,infrared, optical and X-ray continuum data from various databases and comparedthe results with control samples of Broad Line Seyfert 1 galaxies (BLSls). We findthat the fraction (~ 6%) of Radio Loud (RL) NLSls is significantly less than thatof BLS1s (~ 13%), which is caused by the lack of radio-very-loud sources in theformer. The rarity of RL NLS1s, especially radio-very-loud ones, is consistent withthe scenario of small black hole and high accretion rate for NLSls. Six new radio loudNLSls are found and five RL NLS1 candidates are presented. In comparison withthe BLS1s, the NLS1s tend to have stronger far infrared emission, cooler infraredcolors and redder B- K color, which suggests that NLS1s are hosted by dust-richernuclei. The NLS1s also show steeper soft X-ray spectrum and large soft X-rayto optical flux ratio, while a significant fraction show fiat soft X-ray spectra. Atleast two factors can account for this, absorption and spectral variability. We alsoperform a correlation analysis between various broad band data. It is found thatmost correlations identified for NLS1s are also valid for radio quiet BLS1s: (1) theoptical colors are anti-correlated with X-ray spectral index; (2) higher optical, X-ray and NIR luminosity objects show bluer optical colors and red H - K color; (3)higher luminosity objects show warmer IRAS color; (4) the radio loudness correlateswith B - K and X-ray to optical flux ratio. Radio loud objects behave somewhatdifferently in a few correlations.

  2. The parsec-scale structure of radio-loud broad absorption line quasars

    CERN Document Server

    Bruni, G; Mack, K -H; Montenegro-Montes, F M; González-Serrano, J I; Holt, J; Jiménez-Luján, F

    2013-01-01

    Broad Absorption Line Quasars (BAL QSOs) belong to a class of objects not well-understood as yet. Their UV spectra show BALs in the blue wings of the UV resonance lines, due to ionized gas with outflow velocities up to 0.2 c. They can have radio emission difficult to characterize, and that needs to be studied at various wavelengths and resolutions. We aim at studying the pc-scale properties of their synchrotron emission, and in particular at determining their core properties. We performed observations in Very Long Baseline Interferometry (VLBI) technique, using both the European VLBI Network (EVN) at 5 GHz, and the Very Long Baseline Array (VLBA) at 5 and 8.4 GHz to map the pc-scale structure of the brightest radio-loud objects of our sample, allowing a proper morphological interpretation. A variety of morphologies have been found: 9 BAL QSOs on a total of 11 observed sources have a resolved structure. Core-jet, double and symmetric objects are present, suggesting different orientations. In some cases the sou...

  3. Restarting radio activity and dust emission in radio-loud broad absorption line quasars

    CERN Document Server

    Bruni, G; Montenegro-Montes, F M; Brienza, M; González-Serrano, J I

    2015-01-01

    Broad absorption line quasars (BAL QSOs) are objects showing absorption from relativistic outflows, with velocities up to 0.2c. These manifest, in about 15% of quasars, as absorption troughs on the blue side of UV emission lines, such as C iv and Mg ii. In this work, we complement the information collected in the cm band for our previously presented sample of radio loud BAL QSOs with new observations at m and mm bands. Our aim is to verify the presence of old, extended radio components in the MHz range, and probe the emission of dust (linked to star formation) in the mm domain. We observed 5 sources from our sample, already presenting hints of low-frequency emission, with the GMRT at 235 and 610 MHz. Other 17 sources (more than half the sample) were observed with bolometer cameras at IRAM-30m and APEX. All sources observed with the GMRT present extended emission at a scale of tens of kpc. In some cases these measurements allow us to identify a second component in the SED, at frequencies below 1.4 GHz, beyond ...

  4. A Catalog of Broad Absorption Line Quasars in Sloan Digital Sky Survey Data Release 5

    CERN Document Server

    Gibson, Robert R; Brandt, W N; Hall, Patrick B; Shen, Yue; Wu, Jianfeng; Anderson, Scott F; Schneider, Donald P; Berk, Daniel Vanden; Gallagher, S C; Fan, Xiaohui; York, Donald G

    2008-01-01

    We present a catalog of 5039 broad absorption line (BAL) quasars (QSOs) in the Sloan Digital Sky Survey (SDSS) Data Release 5 (DR5) QSO catalog that have absorption troughs covering a continuous velocity range >= 2000 km/s. We have fit ultraviolet (UV) continua and line emission in each case, enabling us to report common diagnostics of BAL strengths and velocities in the range -25,000 to 0 km/s for SiIV $\\lambda$1400, CIV $\\lambda$1549, AlIII $\\lambda$1857, and MgII $\\lambda$2799. We calculate these diagnostics using the spectrum listed in the DR5 QSO catalog, and also for spectra from additional SDSS observing epochs when available. In cases where BAL QSOs have been observed with Chandra or XMM-Newton, we report the X-ray monochromatic luminosities of these sources. We confirm and extend previous findings that BAL QSOs are more strongly reddened in the rest-frame UV than non-BAL QSOs and that BAL QSOs are relatively X-ray weak compared to non-BAL QSOs. The observed BAL fraction is dependent on the spectral s...

  5. Searching for Binary Supermassive Black Holes via Variable Broad Emission Line Shifts: Low Binary Fraction

    CERN Document Server

    Wang, Lile; Ju, Wenhua; Rafikov, Roman R; Ruan, John J; Schneider, Donald P

    2016-01-01

    Supermassive black hole binaries (SMBHs) are expected to result from galaxy mergers, and thus are natural byproducts (and probes) of hierarchical structure formation in the Universe. They are also the primary expected source of low-frequency gravitational wave emission. We search for binary BHs using time-variable velocity shifts in broad Mg II emission lines of quasars with multi-epoch observations. First, we inspect velocity shifts of the binary SMBH candidates identified in Ju et al. (2013), using SDSS spectra with an additional epoch of data that lengthens the typical baseline to ~10 yr. We find variations in the line-of-sight velocity shifts over 10 years that are comparable to the shifts observed over 1-2 years, ruling out the binary model for the bulk of our candidates. We then analyze 1438 objects with 8 yr median time baselines, from which we would expect to see velocity shifts >1000 km/s from sub-pc binaries. We find only one object with an outlying velocity of 448 km/s, indicating, based on our mod...

  6. Locally Optimally-Emitting Clouds and the Variable Broad Emission Line Spectrum of NGC 5548

    CERN Document Server

    Korista, K T; Korista, Kirk T.; Goad, Michael R.

    2000-01-01

    [abridged] We test the ``locally optimally-emitting clouds'' (LOC) model against the extensive spectroscopic data base of the Seyfert~1, NGC 5548. The time-averaged, integrated-light UV broad emission line spectrum from the 1993 global geometric parameters: the outer radius, the index controlling the radial cloud covering fraction of the continuum source, and the integrated cloud covering fraction. We make an {\\em ad~hoc} selection from the range of successful models, and for a simple spherical BLR geometry we simulate the emission line light curves for the 1989 {\\em IUE} and 1993 {\\em HST} campaigns, using the respective observed UV continuum light curves as drivers. We find good agreement between the predicted and observed light curves and lags --- a demonstration of the LOC picture's viability as a means to understanding the BLR environment. Finally, we discuss the next step in developing the LOC picture which involves the marriage of echo-mapping techniques with spectral simulation grids such as those pre...

  7. Gamma-ray opacity of the anisotropic stratified broad-line regions in blazars

    CERN Document Server

    Abolmasov, Pavel

    2016-01-01

    The GeV-range spectra of blazars are shaped not only by non-thermal emission processes internal to the relativistic jet but also by external pair-production absorption on the thermal emission of the accretion disc and the broad-line region (BLR). For the first time, we compute here the pair-production opacities in the GeV range produced by a realistic BLR accounting for the radial stratification and radiation anisotropy. Using photoionization modelling with the CLOUDY code, we calculate a series of BLR models of different sizes, geometries, cloud densities, column densities and metallicities. The strongest emission features in the model BLR are Ly$\\alpha$ and HeII Ly$\\alpha$. Contribution of recombination continua is smaller, especially for hydrogen, because Ly continuum is efficiently trapped inside the large optical depth BLR clouds and converted to Lyman emission lines and higher-order recombination continua. The largest effects on the gamma-ray opacity are produced by the BLR geometry and localization of ...

  8. Iron K Line Variability in the Low-Luminosity AGN NGC 4579

    Science.gov (United States)

    Terashima, Yuichi; Ho, Luis C.; Ptak, Andrew F.; Yaqoob, Tahir; Kunieda, Hideyo; Misaki, Kazutami; Serlemitsos, Peter J.; White, Nicholas E. (Technical Monitor)

    2000-01-01

    We present results of new ASCA observations of the low-luminosity AGN (LLAGN) NGC 4579 obtained in 1998 December 18 and 28, and we report on detection of variability of an iron K emission line. The X-ray luminosities in the 2-10 keV band for the two observations are nearly identical, L(sub X) approximately = 2 x 10(exp 4l) ergs/s, but they are approximately 35% larger than that measured in 1995 July by Terashima et al. (1998). An Fe K emission line is detected at 6.39 +/- 0.09 keV (source rest frame) which is lower than the line energy 6.73(sup +0.13, sub -0.12) keV in the 1995 observation. If we fit the Fe lines with a blend of two Gaussians centered at 6.4 keV and 6.73 KeV, the intensity of the 6.7 keV line decreased, while the intensity of the 6.4 keV line increased, within an interval of 3.5 years. This variability rules out thermal plasmas in the host galaxy as the origin of the ionized Fe line in this LLAGN. The detection and variability of the 6.4 keV line suggest that an optically thick standard accretion disk is present and subtends a large solid angle viewed from the nucleus at the Eddington ratio of L(sub Bol)/L(sub Eddington) approximately 2 x 10(exp -3) (Ho 1999). A broad disk-line profile is not clearly seen and the structure of the innermost part of accretion disk remains unclear.

  9. MULTIWAVELENGTH VARIABILITY OF THE BROAD LINE RADIO GALAXY 3C 120

    International Nuclear Information System (INIS)

    We present results from a multiyear monitoring campaign of the broad-line radio galaxy 3C 120, using the Rossi X-ray Timing Explorer for nearly five years of observations. Additionally, we present coincident optical monitoring using data from several ground-based observatories. Both the X-ray and optical emission are highly variable and appear to be strongly correlated, with the X-ray emission leading the optical by 28 days. The X-ray power density spectrum is best fit by a broken power law, with a low-frequency slope of -1.2, breaking to a high-frequency slope of -2.1, and a break frequency of log νb = -5.75 Hz, or 6.5 days. This value agrees well with the value expected based on 3C 120's mass and accretion rate. We find no evidence for a second break in the power spectrum. Combined with a moderately soft X-ray spectrum (Γ = 1.8) and a moderately high accretion rate, this indicates that 3C 120 fits in well with the high/soft variability state found in most other active galactic nuclei. Previous studies have shown that the spectrum has a strong Fe Kα line, which may be relativistically broadened. The presence of this line, combined with a power spectrum similar to that seen in Seyfert galaxies, suggests that the majority of the X-ray emission in this object arises in or near the disk, and not in the jet.

  10. A CENSUS OF BROAD-LINE ACTIVE GALACTIC NUCLEI IN NEARBY GALAXIES: COEVAL STAR FORMATION AND RAPID BLACK HOLE GROWTH

    International Nuclear Information System (INIS)

    We present the first quantified, statistical map of broad-line active galactic nucleus (AGN) frequency with host galaxy color and stellar mass in nearby (0.01 < z < 0.11) galaxies. Aperture photometry and z-band concentration measurements from the Sloan Digital Sky Survey are used to disentangle AGN and galaxy emission, resulting in estimates of uncontaminated galaxy rest-frame color, luminosity, and stellar mass. Broad-line AGNs are distributed throughout the blue cloud and green valley at a given stellar mass, and are much rarer in quiescent (red sequence) galaxies. This is in contrast to the published host galaxy properties of weaker narrow-line AGNs, indicating that broad-line AGNs occur during a different phase in galaxy evolution. More luminous broad-line AGNs have bluer host galaxies, even at fixed mass, suggesting that the same processes that fuel nuclear activity also efficiently form stars. The data favor processes that simultaneously fuel both star formation activity and rapid supermassive black hole accretion. If AGNs cause feedback on their host galaxies in the nearby universe, the evidence of galaxy-wide quenching must be delayed until after the broad-line AGN phase.

  11. The Corona of the Broad-line Radio Galaxy 3C 390.3

    Science.gov (United States)

    Lohfink, A. M.; Ogle, P.; Tombesi, F.; Walton, D.; Baloković, M.; Zoghbi, A.; Ballantyne, D. R.; Boggs, S. E.; Christensen, F. E.; Craig, W. W.; Fabian, A. C.; Hailey, C. J.; Harrison, F. A.; King, A. L.; Madejski, G.; Matt, G.; Reynolds, C. S.; Stern, D.; Ursini, F.; Zhang, W. W.

    2015-11-01

    We present the results from a joint Suzaku/NuSTAR broadband spectral analysis of 3C 390.3. The high quality data enables us to clearly separate the primary continuum from the reprocessed components allowing us to detect a high energy spectral cut-off ({E}{cut}={117}-14+18 keV), and to place constraints on the Comptonization parameters of the primary continuum for the first time. The hard over soft compactness is {69}-24+124 and the optical depth is {4.1}-3.6+0.5, this leads to an electron temperature of {30}-8+32 keV. Expanding our study of the Comptonization spectrum to the optical/UV by studying the simultaneous Swift-UVOT data, we find indications that the compactness of the corona allows only a small fraction of the total UV/optical flux to be Comptonized. Our analysis of the reprocessed emission show that 3C 390.3 only has a small amount of reflection (R ∼ 0.3), and of that the vast majority is from distant neutral matter. However, we also discover a soft-X-ray excess in the source, which can be described by a weak ionized reflection component from the inner parts of the accretion disk. In addition to the backscattered emission, we also detect the highly ionized iron emission lines Fe xxv and Fe xxvi.

  12. Testing the Kerr metric with the iron line and the KRZ parametrization

    CERN Document Server

    Ni, Yueying; Bambi, Cosimo

    2016-01-01

    The spacetime geometry around astrophysical black holes is supposed to be well approximated by the Kerr metric, but deviations from the Kerr solution are predicted in a number of scenarios involving new physics. Broad iron K$\\alpha$ lines are commonly observed in the X-ray spectrum of black holes and originate by X-ray fluorescence of the inner accretion disk. The profile of the iron line is sensitively affected by the spacetime geometry in the strong gravity region and can be used to test the Kerr black hole hypothesis. In this paper, we extend previous work in the literature. In particular: i) as test-metric, we employ the parametrization recently proposed by Konoplya, Rezzolla, and Zhidenko, which has a number of subtle advantages with respect to the existing approaches; ii) we perform simulations with specific X-ray missions, and we consider NuSTAR as a prototype of current observational facilities and eXTP as an example of the next generation of X-ray observatories. We find a significant difference betwe...

  13. Variability of the X-ray Broad Iron Spectral Features in Active Galactic Nuclei and Black-hole Binaries

    CERN Document Server

    Mizumoto, Misaki; Tsujimoto, Masahiro; Inoue, Hajime

    2015-01-01

    The "broad iron spectral features" are often seen in X-ray spectra of Active Galactic Nuclei (AGN) and black-hole binaries (BHB). These features may be explained either by the "relativistic disc reflection" scenario or the "partial covering" scenario: It is hardly possible to determine which model is valid from time-averaged spectral analysis. Thus, X-ray spectral variability has been investigated to constrain spectral models. To that end, it is crucial to study iron structure of BHBs in detail at short time-scales, which is, for the first time, made possible with the Parallel-sum clocking (P-sum) mode of XIS detectors on board Suzaku. This observational mode has a time-resolution of 7.8~ms as well as a CCD energy-resolution. We have carried out systematic calibration of the P-sum mode, and investigated spectral variability of the BHB GRS 1915+105. Consequently, we found that the spectral variability of GRS 1915+105 does not show iron features at sub-seconds. This is totally different from variability of AGN ...

  14. An extreme, blueshifted iron line profile in the Narrow Line Seyfert 1 PG 1402+261; an edge-on accretion disk or highly ionized absorption?

    CERN Document Server

    Reeves, J N; 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 (FWHM velocity of 110000 km/s) iron K-shell emission line. The line centroid energy at 7.3 keV appears blue-shifted with respect to the iron Kalpha emission band between 6.4-6.97 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 deg 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 instead b...

  15. Revisiting correlations between broad-line and jet emission variations for AGNs: 3C 120 and 3C 273

    Science.gov (United States)

    Liu, H. T.; Bai, J. M.; Feng, H. C.; Li, S. K.

    2015-06-01

    We restudy the issue of cross-correlations between broad-line and jet emission variations, and aim to locate the position of a radio (and gamma-ray) emitting region in a jet of active galactic nuclei. Considering the radial profiles of the radius and number density of clouds in a spherical broad-line region (BLR), we derive new formulae connecting the jet-emitting position Rjet to the time lag τob between broad-line and jet emission variations, and the BLR radius. Also, formulae are derived for a disc-like BLR and a spherical shell BLR. The model-independent flux randomization/random subset selection method is used to estimate τob. For 3C 120, positive lags of about 0.3 yr are found between the 15 GHz emission and the Hβ, Hγ and He II λ4686 lines, including broad-line data in a newly published paper, indicating that the line variations lead the 15 GHz ones. Each of the broad-line light curves corresponds to a radio outburst. Rjet = 1.1-1.5 parsec (pc) is obtained for 3C 120. For 3C 273, a common feature of negative time lags is found in the cross-correlation functions between light curves of radio emission and the Balmer lines, as well as Lyα λ1216 and C IV λ1549 lines. Rjet = 1.0-2.6 pc is obtained for 3C 273. The estimated Rjet is comparable for 3C 120 and 3C 273, and the gamma-ray-emitting positions will be within ˜1-3 pc from the central engines. Comparisons show that the cloud number density and radius radial distributions and the BLR structures have only negligible effects on Rjet.

  16. Kinematics and Structure of Clumps in Broad-line Regions in Active Galactic Nuclei

    CERN Document Server

    Ghayuri, Mohammad

    2016-01-01

    We use the Jeans equations for an ensemble of collisionless particles to describe the distribution of broad-line region (BLR) cloud in three classes: (A) non disc (B) disc-wind (c) pure disc structure. We propose that clumpy structures in the brightest quasars belong to class A, fainter quasars and brighter Seyferts belong to class B, and dimmer Seyfert galaxies and all low-luminosity AGNs (LLAGNs) belong to class C. We derive the virial factor, $f$, for disc-like structures and find a negative correlation between the inclination angle, $\\theta_{0}$, and $f$. We find similar behaviour for $f$ as a function of the FWHM and $\\sigma_{z}$, the $z$ component of velocity dispersion. For different values of $\\theta_{0}$ we find that $ 1.0 \\lesssim f \\lesssim 9.0 $ in type1 AGNs and $ 0.5 \\lesssim f \\lesssim 1.0 $ in type2 AGNs. Moreover we have $ 0.5 \\lesssim f \\lesssim 6.5 $ for different values of FWHM and $ 1.4 \\lesssim f \\lesssim 1.8 $ for different values of $ \\sigma_{z} $. We also find that $ f $ is relatively...

  17. Evidence for magnetar formation in broad-lined type Ic supernovae 1998bw and 2002ap

    CERN Document Server

    Wang, L J; Liu, L D; Wang, S Q; Han, Y H; Xu, D; Dai, Z G; Qiu, Y L; Wei, J Y

    2016-01-01

    Broad-lined type Ic supernovae (SNe Ic-BL) are peculiar stellar explosions that distinguish themselves from ordinary SNe. Some SNe Ic-BL are associated with long-duration (\\gtrsim 2 s) gamma-ray bursts (GRBs). Black holes and magnetars are two types of compact objects that are hypothesized to be central engines of GRBs. In spite of decades of investigations, no direct evidence for the formation of black holes or magnetars has been found for GRBs so far. Here we report the discovery that the early peak (t \\lesssim 50 days) and late-time (t \\gtrsim 300 days) slow decay displayed in the light curves of both SNe 1998bw (associated with GRB 980425) and 2002ap (not GRB-associated) can be attributed to magnetar spin-down with initial rotation period P0 \\sim 20 ms, while the intermediate-time (50 \\lesssim t \\lesssim 300 days) linear decline is caused by radioactive decay of 56Ni. The connection between the early peak and late-time slow decline in the light curves is unexpected in alternative models. We thus suggest t...

  18. The Compact Structure of Radio-Loud Broad Absorption Line Quasars

    CERN Document Server

    Liu, Y; Wang, T G; Xie, F G

    2008-01-01

    We present the results of EVN+MERLIN VLBI polarization observations of 8 Broad Absorption Line (BAL) quasars at 1.6 GHz, including 4 LoBALs and 4 HiBALs with either steep or flat spectra on VLA scales. Only one steep-spectrum source, J1122+3124, shows two-sided structure on the scale of 2 kpc. The other four steep-spectrum sources and three flat-spectrum sources display either an unresolved image or a core-jet structure on scales of less than three hundred parsecs. In all cases the marginally resolved core is the dominant radio component. Linear polarization in the cores has been detected in the range of a few to 10 percent. Polarization, together with high brightness temperatures (from 2*10^9-5*10^10 K), suggest a synchrotron origin for the radio emission. There is no apparent difference in the radio orphologies or polarization between low-ionization and high-ionization BAL QSOs nor between flat- and steep-spectrum sources. We discuss the orientation of BAL QSOs with both flat and steep spectra, and consider...

  19. The compact structure of radio-loud broad absorption line quasars

    Science.gov (United States)

    Liu, Y.; Jiang, D. R.; Wang, T. G.; Xie, F. G.

    2008-11-01

    We present the results of EVN+MERLIN very long baseline interferometry (VLBI) polarization observations of eight broad absorption line (BAL) quasars at 1.6 GHz, including four low-ionization BAL quasars (LoBALs) and four high-ionization BAL quasars (HiBALs) with either steep or flat spectra on Very Large Array (VLA) scales. Only one steep-spectrum source, J1122+3124, shows two-sided structure on the scale of 2 kpc. The other four steep-spectrum sources and three flat-spectrum sources display either an unresolved image or a core-jet structure on scales of less than 300 pc. In all cases, the marginally resolved core is the dominant radio component. Linear polarization in the cores has been detected in the range of a few to 10 per cent. Polarization, together with high brightness temperatures (from 2 × 109 to 5 × 1010K), suggests a synchrotron origin for the radio emission. There is no apparent difference in the radio morphologies or polarization between low-ionization and high-ionization BAL quasi-stellar objects (QSOs) or between flat- and steep-spectrum sources. We discuss the orientation of BAL QSOs with both flat and steep spectra, and consider a possible evolutionary scenario for BAL QSOs. In this scenario, BAL QSOs are probably a young population of radio sources that are compact steep spectrum or GHz peaked radio source analogues at the low end of radio power.

  20. The Lick AGN Monitoring Project 2011: Dynamical Modeling of the Broad Line Region in Mrk 50

    CERN Document Server

    Pancoast, Anna; Treu, Tommaso; Barth, Aaron J; Bennert, Vardha N; Canalizo, Gabriela; Filippenko, Alexei V; Gates, Elinor L; Greene, Jenny E; Li, Weidong; Malkan, Matthew A; Sand, David J; Stern, Daniel; Woo, Jong-Hak; Assef, Roberto J; Bae, Hyun-Jin; Buehler, Tabitha; Cenko, S Bradley; Clubb, Kelsey I; Cooper, Michael C; Diamond-Stanic, Aleksandar M; Hiner, Kyle D; Hoenig, Sebastian F; Joner, Michael D; Kandrashoff, Michael T; Laney, C David; Lazarova, Mariana S; Nierenberg, A M; Park, Dawoo; Silverman, Jeffrey M; Son, Donghoon; Sonnenfeld, Alessandro; Thorman, Shawn J; Tollerud, Erik J; Walsh, Jonelle L; Walters, Richard

    2012-01-01

    We present dynamical modeling of the broad line region (BLR) in the Seyfert 1 galaxy Mrk 50 using reverberation mapping data taken as part of the Lick AGN Monitoring Project (LAMP) 2011. We model the reverberation mapping data directly, constraining the geometry and kinematics of the BLR, as well as deriving a black hole mass estimate that does not depend on a normalizing factor or virial coefficient. We find that the geometry of the BLR in Mrk 50 is a nearly face-on thick disk, with a mean radius of 9.6(+1.2,-0.9) light days, a width of the BLR of 6.9(+1.2,-1.1) light days, and a disk opening angle of 25\\pm10 degrees above the plane. We also constrain the inclination angle to be 9(+7,-5) degrees, close to face-on. Finally, the black hole mass of Mrk 50 is inferred to be log10(M(BH)/Msun) = 7.57(+0.44,-0.27). By comparison to the virial black hole mass estimate from traditional reverberation mapping analysis, we find the normalizing constant (virial coefficient) to be log10(f) = 0.78(+0.44,-0.27), consistent ...

  1. Solving the 56Ni puzzle of magnetar-powered broad-lined type Ic supernovae

    CERN Document Server

    Wang, Ling-Jun; Xu, Dong; Wang, Shan-Qin; Dai, Zi-Gao; Wu, Xue-Feng; Wei, Jian-Yan

    2016-01-01

    Broad-lined type Ic supernovae (SNe Ic-BL) are of great importance because their association with long-duration gamma-ray bursts (LGRBs) holds the key to deciphering the central engine of LGRBs, which refrains from being unveiled despite decades of investigation. Among the two popularly hypothesized types of central engine, i.e., black holes and strongly magnetized neutron stars (magnetars), there is mounting evidence that the central engine of GRB-associated SNe (GRB-SNe) is rapidly rotating magnetars. Theoretical analysis also suggests that magnetars could be the central engine of SNe Ic-BL. What puzzled the researchers is the fact that light curve modeling indicates that as much as 0.2-0.5 solar mass of 56Ni was synthesized during the explosion of the SNe Ic-BL, which is unfortunately in direct conflict with current state-of-the-art understanding of magnetar-powered 56Ni synthesis. Here we propose a dynamic model of magnetar-powered SNe to take into account the acceleration of the ejecta by the magnetar, a...

  2. Radio Through X-ray Spectral Energy Distributions of 38 Broad Absorption Line Quasars

    CERN Document Server

    Gallagher, S C; Brandt, W N; Egami, E; Hines, D C; Priddey, R S

    2007-01-01

    We have compiled the largest sample of multiwavelength spectral energy distributions (SEDs) of Broad Absorption Line (BAL) quasars to date, from the radio to the X-ray. We present new Spitzer MIPS (24, 70, and 160 micron) observations of 38 BAL quasars in addition to data from the literature and public archives. In general, the mid-infrared properties of BAL quasars are consistent with those of non-BAL quasars of comparable luminosity. In particular, the optical-to-mid-infrared luminosity ratios of the two populations are indistinguishable. We also measure or place upper limits on the contribution of star formation to the far-infrared power. Of 22 (57%) upper limits, seven quasars have sufficiently sensitive constraints to conclude that star formation likely contributes little (<20%) to their far-infrared power. The 17 BAL quasars (45%) with detected excess far-infrared emission likely host hyperluminous starbursts with L_fir,SF=10^{13-14} L_sun. Mid-infrared through X-ray composite BAL quasar SEDs are pre...

  3. Classifying Broad Absorption Line Quasars: Metrics, Issues and a New Catalogue Constructed from SDSS DR5

    CERN Document Server

    Scaringi, S; Knigge, C; Goad, M R

    2009-01-01

    We apply a recently developed method for classifying broad absorption line quasars (BALQSOs) to the latest QSO catalogue constructed from Data Release 5 of the Sloan Digital Sky Survey. Our new hybrid classification scheme combines the power of simple metrics, supervised neural networks and visual inspection. In our view the resulting BALQSO catalogue is both more complete and more robust than all previous BALQSO catalogues, containing 3552 sources selected from a parent sample of 28,421 QSOs in the redshift range 1.7

  4. The Long-Term X-Ray Variability of Broad Absorption Line Quasars

    CERN Document Server

    Saez, Cristian; Gallagher, Sarah C; Bauer, Franz E; Garmire, Gordon P

    2012-01-01

    We analyze the long-term (rest-frame 3-30 yr) X-Ray variability of eleven broad absorption line (BAL) quasars, mainly to constrain the variation properties of the X-Ray absorbing shielding gas that is thought to play a critical role in BAL wind launching. Our BAL quasar sample has coverage with multiple X-ray observatories including Chandra, XMM-Newton, BeppoSAX, ASCA, ROSAT, and Einstein; 3-11 observations are available for each source. For seven of the eleven sources we have obtained and analyzed new Chandra observations suitable for searching for any strong X-ray variability. We find highly significant X-Ray variability in three sources (PG 1001+054, PG 1004+130, and PG 2112+059). The maximum observed amplitude of the 2-8 keV variability is a factor of $3.8\\pm 1.3$, $1.5\\pm 0.2$, and $9.9\\pm 2.3$ for PG 1001+054, PG 1004+130, and PG 2112+059, respectively, and these sources show detectable variability on rest-frame timescales down to 5.8, 1.4, and 0.5 yr. For PG 1004+130 and PG 2112+059 we also find signif...

  5. CIV Broad Absorption Line Acceleration in Sloan Digital Sky Survey Quasars

    CERN Document Server

    Grier, C J; Hall, P B; Trump, J R; Ak, N Filiz; Anderson, S F; Green, Paul J; Schneider, D P; Sun, M; Vivek, M; Beatty, T G; Brownstein, Joel R; Roman-Lopes, Alexandre

    2016-01-01

    We present results from the largest systematic investigation of broad absorption line (BAL) acceleration to date. We use spectra of 140 quasars from three Sloan Digital Sky Survey programs to search for global velocity offsets in BALs over timescales of ~2.5-5.5 years in the quasar rest frame. We carefully select acceleration candidates by requiring monolithic velocity shifts over the entire BAL trough, avoiding BALs with velocity shifts that might be caused by profile variability. The CIV BALs of two quasars show velocity shifts consistent with the expected signatures of BAL acceleration, and the BAL of one quasar shows a velocity-shift signature of deceleration. In our two acceleration candidates, we see evidence that the magnitude of the acceleration is not constant over time; the magnitudes of the change in acceleration for both acceleration candidates are difficult to produce with a standard disk-wind model or via geometric projection effects. We measure upper limits to acceleration and deceleration for ...

  6. Gamma-Gamma Absorption in the Broad Line Region Radiation Fields of Gamma-Ray Blazars

    CERN Document Server

    Boettcher, Markus

    2016-01-01

    The expected level of gamma-gamma absorption in the Broad Line Region (BLR) radiation field of gamma-ray loud Flat Spectrum Radio Quasars (FSRQs)is evaluated as a function of the location of the gamma-ray emission region. This is done self-consistently with parameters inferred from the shape of the spectral energy distribution (SED) in a single-zone leptonic EC-BLR model scenario. We take into account all geometrical effects both in the calculation of the gamma-gamma opacity and the normalization of the BLR radiation energy density. As specific examples, we study the FSRQs 3C279 and PKS 1510-089, keeping the BLR radiation energy density at the location of the emission region fixed at the values inferred from the SED. We confirm previous findings that the optical depth due to $\\gamma\\gamma$ absorption in the BLR radiation field exceeds unity for both 3C279 and PKS 1510-089 for locations of the gamma-ray emission region inside the inner boundary of the BLR. It decreases monotonically, with distance from the cen...

  7. The different origins of high- and low-ionization broad emission lines revealed by gravitational microlensing in the Einstein cross

    Science.gov (United States)

    Braibant, L.; Hutsemékers, D.; Sluse, D.; Anguita, T.

    2016-07-01

    We investigate the kinematics and ionization structure of the broad emission line region of the gravitationally lensed quasar QSO2237+0305 (the Einstein cross) using differential microlensing in the high- and low-ionization broad emission lines. We combine visible and near-infrared spectra of the four images of the lensed quasar and detect a large-amplitude microlensing effect distorting the high-ionization CIV and low-ionization Hα line profiles in image A. While microlensing only magnifies the red wing of the Balmer line, it symmetrically magnifies the wings of the CIV emission line. Given that the same microlensing pattern magnifies both the high- and low-ionization broad emission line regions, these dissimilar distortions of the line profiles suggest that the high- and low-ionization regions are governed by different kinematics. Since this quasar is likely viewed at intermediate inclination, we argue that the differential magnification of the blue and red wings of Hα favors a flattened, virialized, low-ionization region whereas the symmetric microlensing effect measured in CIV can be reproduced by an emission line formed in a polar wind, without the need of fine-tuned caustic configurations. Based on observations made with the ESO-VLT, Paranal, Chile; Proposals 076.B-0197 and 076.B-0607 (PI: Courbin).

  8. VARIABLE REDDENING AND BROAD ABSORPTION LINES IN THE NARROW-LINE SEYFERT 1 GALAXY WPVS 007: AN ORIGIN IN THE TORUS

    Energy Technology Data Exchange (ETDEWEB)

    Leighly, Karen M.; Cooper, Erin [Homer L. Dodge Department of Physics and Astronomy, The University of Oklahoma, 440 W. Brooks Street, Norman, OK 73019 (United States); Grupe, Dirk [Department of Earth and Space Science, Morehead State University, 235 Martindale Drive, Morehead, KY 40351 (United States); Terndrup, Donald M. [Department of Astronomy, The Ohio State University, 140 W. 18th Avenue, Columbus, OH 43210 (United States); Komossa, S. [Max-Planck Institut für Radioastronmie, Auf dem Hügel 69, D-53121 Bonn (Germany)

    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.

  9. The different origins of high- and low-ionization broad emission lines revealed by gravitational microlensing in the Einstein cross

    CERN Document Server

    Braibant, Lorraine; Sluse, Dominique; Anguita, Timo

    2016-01-01

    We investigate the kinematics and ionization structure of the broad emission line region of the gravitationally lensed quasar QSO2237+0305 (the Einstein cross) using differential microlensing in the high- and low-ionization broad emission lines. We combine visible and near-infrared spectra of the four images of the lensed quasar and detect a large-amplitude microlensing effect distorting the high-ionization CIV and low-ionization H$\\alpha$ line profiles in image A. While microlensing only magnifies the red wing of the Balmer line, it symmetrically magnifies the wings of the CIV emission line. Given that the same microlensing pattern magnifies both the high- and low-ionization broad emission line regions, these dissimilar distortions of the line profiles suggest that the high- and low-ionization regions are governed by different kinematics. Since this quasar is likely viewed at intermediate inclination, we argue that the differential magnification of the blue and red wings of H$\\alpha$ favors a flattened, viri...

  10. The parsec-scale structure of radio-loud broad absorption line quasars

    Science.gov (United States)

    Bruni, G.; Dallacasa, D.; Mack, K.-H.; Montenegro-Montes, F. M.; González-Serrano, J. I.; Holt, J.; Jiménez-Luján, F.

    2013-06-01

    Context. Broad absorption line quasars (BAL QSOs) belong to a class of objects not well-understood as yet. Their UV spectra show BALs in the blue wings of the UV resonance lines, owing to ionized gas with outflow velocities up to 0.2 c. They can have radio emission that is difficult to characterize and that needs to be studied at various wavelengths and resolutions. Aims: We aim to study the pc-scale properties of their synchrotron emission and, in particular, to determine their core properties. Methods: We performed observations in the Very Long Baseline Interferometry (VLBI) technique, using both the European VLBI Network (EVN) at 5 GHz, and the Very Long Baseline Array (VLBA) at 5 and 8.4 GHz to map the pc-scale structure of the brightest radio-loud objects of our sample, allowing a proper morphological interpretation. Results: A variety of morphologies have been found: 9 BAL QSOs on a total of 11 observed sources have a resolved structure. Core-jet, double, and symmetric objects are present, suggesting different orientations. In some cases the sources can be young GPS or CSS. The projected linear size of the sources, also considering observations from our previous work for the same objects, can vary from tens of pc to hundreds of kpc. In some cases, a diffuse emission can be supposed from the missing flux-density with respect to previous lower resolution observations. Finally, the magnetic field strength does not significantly differ from the values found in the literature for radio sources with similar sizes. Conclusions: These results are not easily interpreted with the youth scenario for BAL QSOs, in which they are generally compact objects still expelling a dust cocoon. The variety of orientations, morphologies, and extensions found are presumably related to different possible angles for the BAL producing outflows, with respect to the jet axis. Moreover, the phenomenon could be present in various phases of the QSO evolution. Table 3 is available in

  11. Kinematics and structure of clumps in broad-line regions in active galactic nuclei

    Science.gov (United States)

    Ghayuri, Mohammad

    2016-10-01

    We use the Jeans equations for an ensemble of collisionless particles to describe the distribution of broad-line region (BLR) cloud in three classes: (A) non-disc (B) disc-wind (C) pure disc structure. We propose that clumpy structures in the brightest quasars belong to class A, fainter quasars and brighter Seyferts belong to class B, and dimmer Seyfert galaxies and all low-luminosity AGNs (LLAGNs) belong to class C. We derive the virial factor, f, for disc-like structures and find a negative correlation between the inclination angle, θ0, and f. We find similar behaviour for f as a function of the FWHM and σz, the z component of velocity dispersion. For different values of θ0 we find that 1.0 ≲ f ≲ 9.0 in type1 AGNs and 0.5 ≲ f ≲ 1.0 in type2 AGNs. Moreover we have 0.5 ≲ f ≲ 6.5 for different values of FWHM and 1.4 ≲ f ≲ 1.8 for different values of σz. We also find that f is relatively insensitive to the variations of bolometric luminosity and column density of each cloud and the range of variation of f is in order of 0.01. Considering wide range of f we see the use of average virial factor is not very safe. Therefore we propose AGN community to divide a sample into a few subsamples based on the value of θ0 and FWHM of members and calculate for each group separately to reduce uncertainty in black hole mass estimation.

  12. Solving the 56Ni Puzzle of Magnetar-powered Broad-lined Type IC Supernovae

    Science.gov (United States)

    Wang, Ling-Jun; Han, Yan-Hui; Xu, Dong; Wang, Shan-Qin; Dai, Zi-Gao; Wu, Xue-Feng; Wei, Jian-Yan

    2016-11-01

    Broad-lined Type Ic supernovae (SNe Ic-BL) are of great importance because their association with long-duration gamma-ray bursts (LGRBs) holds the key to deciphering the central engine of LGRBs, which refrains from being unveiled despite decades of investigation. Among the two popularly hypothesized types of central engine, i.e., black holes and strongly magnetized neutron stars (magnetars), there is mounting evidence that the central engine of GRB-associated SNe (GRB-SNe) is rapidly rotating magnetars. Theoretical analysis also suggests that magnetars could be the central engine of SNe Ic-BL. What puzzled the researchers is the fact that light-curve modeling indicates that as much as 0.2{--}0.5 {M}ȯ of 56Ni was synthesized during the explosion of the SNe Ic-BL, which is unfortunately in direct conflict with current state-of-the-art understanding of magnetar-powered 56Ni synthesis. Here we propose a dynamic model of magnetar-powered SNe to take into account the acceleration of the ejecta by the magnetar, as well as the thermalization of the injected energy. Assuming that the SN kinetic energy comes exclusively from the magnetar acceleration, we find that although a major fraction of the rotational energy of the magnetar is to accelerate the SN ejecta, a tiny fraction of this energy deposited as thermal energy of the ejecta is enough to reduce the needed 56Ni to 0.06 M ⊙ for both SN 1997ef and SN 2007ru. We therefore suggest that magnetars could power SNe Ic-BL in aspects both of energetics and of 56Ni synthesis.

  13. Iron K$\\alpha$ line of boson stars

    CERN Document Server

    Cao, Zheng; Zhou, Menglei; Bambi, Cosimo; Herdeiro, Carlos A R; Radu, Eugen

    2016-01-01

    The present paper is a sequel to our previous work [Y. Ni et al., JCAP 1607, 049 (2016)] in which we studied the iron K$\\alpha$ line expected in the reflection spectrum of Kerr black holes with scalar hair. These metrics are solutions of Einstein's gravity minimally coupled to a massive, complex scalar field. They form a continuous bridge between a subset of Kerr black holes and a family of rotating boson stars depending on one extra parameter, the dimensionless scalar hair parameter $q$, ranging from 0 (Kerr black holes) to 1 (boson stars). Here we study the limiting case $q=1$, corresponding to rotating boson stars. For comparison, spherical boson stars are also considered. We simulate observations with XIS/Suzaku. Using the fact that current observations are well fit by the Kerr solution and thus requiring that acceptable alternative compact objects must be compatible with a Kerr fit, we find that some boson star solutions are relatively easy to rule out as potential candidates to explain astrophysical bla...

  14. An Extreme, Blueshifted Iron-Line Profile in the Narrow-Line Seyfert 1 PG 1402+261: An Edge-on Accretion Disk or Highly Ionized Absorption?

    Science.gov (United States)

    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.

  15. The ASCA X-Ray Spectrum Of The Broad-Line Radio Galaxy Pictor A A Simple Power Law With No Fe K-$\\alpha$ Line

    CERN Document Server

    Eracleous, M; Eracleous, Michael; Halpern, Jules P.

    1998-01-01

    We present the X-ray spectrum of the broad-line radio galaxy Pictor A as observed by ASCA in 1996. The main objective of the observation was to detect and study the profiles of the Fe~K$\\alpha$ lines. The motivation was the fact that the Balmer lines of this object show well-separated displaced peaks, suggesting an origin in an accretion disk. The 0.5-10 keV X-ray spectrum is described very well by a model consisting of a power law of photon index 1.77 modified by interstellar photoelectric absorption. We find evidence for neither a soft nor a hard (Compton reflection) excess. More importantly, we do not detect an Fe K-alpha line, in marked contrast with the spectra of typical Seyfert galaxies and other broad-line radio galaxies observed by ASCA. The 99%-confidence upper limit on the equivalent width of an unresolved line at a rest energy of 6.4 keV is 100 eV, while for a broad line (FWHM of approximately 60,000 km/s) the corresponding upper limit is 135 eV. We discuss several possible explanations for the we...

  16. Active galactic nuclei at z ˜ 1.5 - II. Black hole mass estimation by means of broad emission lines

    Science.gov (United States)

    Mejía-Restrepo, J. E.; Trakhtenbrot, B.; Lira, P.; Netzer, H.; Capellupo, D. M.

    2016-07-01

    This is the second in a series of papers aiming to test how the mass (MBH), accretion rate (Ṁ) and spin (a*) of supermassive black holes (SMBHs) determine the observed properties of type I active galactic nuclei (AGN). Our project utilizes a sample of 39 unobscured AGN at z ≃ 1.55 observed by Very Large Telescope/X-Shooter, selected to map a large range in MBH and L/LEdd and covers the most prominent UV-optical (broad) emission lines, including Hα, Hβ, Mg II λ2798 and C IV λ1549. This paper focuses on single-epoch, `virial' MBH determinations from broad emission lines and examines the implications of different continuum modelling approaches in line width measurements. We find that using a local power-law continuum instead of a physically motivated thin disc continuum leads to only slight underestimation of the full width at half-maximum (FWHM) of the lines and the associated MBH(FWHM). However, the line dispersion σline and associated MBH(σline) are strongly affected by the continuum placement and provides less reliable mass estimates than FWHM-based methods. Our analysis shows that Hα, Hβ and Mg II can be safely used for virial MBH estimation. The C IV line, on the other hand, is not reliable in the majority of the cases; this may indicate that the gas emitting this line is not virialized. While Hα and Hβ show very similar line widths, the mean FWHM(Mg II) is about 30 per cent narrower than FWHM(Hβ). We confirm several recent suggestions to improve the accuracy in C IV-based mass estimates, relying on other UV emission lines. Such improvements do not reduce the scatter between C IV-based and Balmer-line-based mass estimates.

  17. Variable Reddening and Broad Absorption Lines in the Narrow-line Seyfert 1 Galaxy WPVS 007: an Origin in the Torus

    CERN Document Server

    Leighly, Karen M; Grupe, Dirk; Terndrup, Donald M; Komossa, S

    2015-01-01

    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 CIV 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 variabl...

  18. The link between broad emission line fluctuations and non-thermal emission from the inner AGN jet

    CERN Document Server

    León-Tavares, J; Lobanov, A; Valtaoja, E; Arshakian, T G

    2014-01-01

    AGN reverberate when the broad emission lines respond to changes of the ionizing thermal continuum emission. Reverberation measurements have been commonly used to estimate the size of the broad-line region (BLR) and the mass of the central black hole. However, reverberation mapping studies have been mostly performed on radio-quiet sources where the contribution of the jet can be neglected. In radio-loud AGN, jets and outflows may affect substantially the relation observed between the ionizing continuum and the line emission. To investigate this relation, we have conducted a series of multiwavelength studies of radio-loud AGN, combining optical spectral line monitoring with regular VLBI observations. Our results suggest that at least a fraction of the broad-line emitting material can be located in a sub-relativistic outflow ionized by non-thermal continuum emission generated in the jet at large distances (> 1pc) from the central engine of AGN. This finding may have a strong impact on black hole mass estimates ...

  19. Space Telescope and Optical Reverberation Mapping Project. IV. Anomalous behavior of the broad ultraviolet emission lines in NGC 5548

    CERN Document Server

    Goad, M R; De Rosa, G; Kriss, G A; Edelson, R; Barth, A J; Ferland, G J; Kochanek, C S; Netzer, H; Peterson, B M; Bentz, M C; Bisogni, S; Crenshaw, D M; Denney, K D; Ely, J; Fausnaugh, M M; Grier, C J; Gupta, A; Horne, K D; Kaastra, J; Pancoast, A; Pei, L; Pogge, R W; Skielboe, A; Starkey, D; Vestergaard, M; Zu, Y; Anderson, M D; Arevalo, P; Bazhaw, C; Borman, G A; Boroson, T A; Bottorff, M C; Brandt, W N; Breeveld, A A; Brewer, B J; Cackett, E M; Carini, M T; Croxall, K V; Bonta, E Dalla; de Lorenzo-Caceres, A; Dietrich, M; Efimova, N V; Evans, P A; Filippenko, A V; Flatland, K; Gehrels, N; Geier, S; Gelbord, G M; Gonzalez, L; Gorjian, V; Grupe, D; Hall, P B; Hicks, S; Horenstein, D; Hutchison, T; Im, M; Jensen, J J; Joner, M D; Jones, J; Kaspi, S; Kelly, B C; Kennea, J A; Kim, M; Kim, S C; Klimanov, S A; Larionov, V M; Lee, J C; Leonard, D C; Lira, P; MacInnis, F; Manne-Nicholas, E R; Mathur, S; McHardy, I M; Montouri, C; Musso, R; Nazarov, S V; Norris, R P; Nousek, J A; Okhmat, D N; Papadakis, I; Parks, J R; Pott, J -U; Rafter, S E; Rix, H -W; Saylor, D A; Schimoia, J S; Schnulle, K; Sergeev, S G; Siegel, M; Spencer, M; Sung, H -I; Teems, K G; Treu, T; Turner, C S; Uttley, P; Villforth, C; Weiss, Y; Woo, J -H; Yan, H; Young, S; Zheng, W -K

    2016-01-01

    During an intensive Hubble Space Telescope (HST) Cosmic Origins Spectrograph (COS) UV monitoring campaign of the Seyfert~1 galaxy NGC 5548 performed from 2014 February to July, the normally highly correlated far-UV continuum and broad emission-line variations decorrelated for ~60 to 70 days, starting ~75 days after the first HST/COS observation. Following this anomalous state, the flux and variability of the broad emission lines returned to a more normal state. This transient behavior, characterised by significant deficits in flux and equivalent width of the strong broad UV emission lines, is the first of its kind to be unambiguously identified in an active galactic nucleus reverberation mapping campaign. The largest corresponding emission-line flux deficits occurred for the high-ionization collisionally excited lines, C IV and Si IV(+O IV]), and also He II(+O III]), while the anomaly in Ly-alpha was substantially smaller. This pattern of behavior indicates a depletion in the flux of photons with E_{\\rm ph} >...

  20. Evidence for an Untruncated Accretion Disk in the Broad-Line Radio Galaxy 4C+74.26

    CERN Document Server

    Ballantyne, D R

    2005-01-01

    We present evidence for a broad, ionized Fe K line in the XMM-Newton spectrum of the broad-line radio galaxy (BLRG) 4C+74.26. This is the first indication that the innermost regions of the accretion flow in BLRGs contain thin, radiatively efficient disks. Analysis of the 35 ks XMM-Newton observation finds a broad line with an inner radius close to the innermost stable circular orbit for a maximally spinning black hole. The outer radius of the relativistic line is also found to be within 10 gravitational radii. The Fe K line profile gives an inclination angle of ~40 degrees, consistent with the radio limit. There are two narrow components to the Fe K complex: one at 6.4 keV from neutral Fe, and one at 6.2 keV. These may form the blue and red horns of a diskline from farther out on the disk, but a longer observation is required to confirm this hypothesis. We discuss the implications of this observation for models of jet production, and suggest that BLRGs and radio-loud quasars will have larger than average blac...

  1. Chandra high resolution spectroscopy of the circumnuclear matter in the Broad Line Radio Galaxy 3C445

    CERN Document Server

    Reeves, J N; Braito, V; Sambruna, R

    2010-01-01

    We present evidence for X-ray line emitting and absorbing gas in the nucleus of the Broad-Line Radio Galaxy (BLRG), 3C 445. A 200ks Chandra LETG observation of 3C 445 reveals the presence of several highly ionized emission lines in the soft X-ray spectrum, primarily from the He and H-like ions of O, Ne, Mg and Si. Radiative recombination emission is detected from O VII and O VIII, indicating that the emitting gas is photoionized. The He-like emission appears to be resolved into forbidden and intercombination line components, which implies a high density of >10^{10} cm^{-3}, while the Oxygen lines are velocity broadened with a mean width of ~2600 km s^{-1} (FWHM). The density and widths of the ionized lines indicate an origin of the gas on sub-parsec scales in the Broad Line Region (BLR).The X-ray continuum of 3C 445 is heavily obscured either by a partial coverer or by a photoionized absorber of column density N_{H}=2x10^{23} cm^{-2} and ionization parameter log(xi)=1.4 erg cm s^{-1}. However the view of the ...

  2. A relativistic iron emission line from the neutron star low-mass X-ray binary GX 3+1

    CERN Document Server

    Piraino, S; Kaaret, P; Mück, B; DÁi', A; DI Salvo, T; Iaria, R; Robba, N; Burderi, L; Egron, E

    2012-01-01

    We present the results of a spectroscopic study of the Fe K{\\alpha} emission of the persistent neutron-star atoll low-mass X-ray binary and type I X-ray burster GX 3+1 with the EPIC-PN on board XMM-Newton. The source shows a flux modulation over several years and we observed it during its fainter phase, which corresponds to an X-ray luminosity of Lx~10^37 ergs/s. When fitted with a two-component model, the X-ray spectrum shows broad residuals at \\sim6-7 keV that can be ascribed to an iron K{\\alpha} fluorescence line. In addition, lower energy features are observed at \\sim3.3 keV, \\sim3.9 keV and might originate from Ar XVIII and Ca XIX. The broad iron line feature is well fitted with a relativistically smeared profile. This result is robust against possible systematics caused by instrumental pile-up effects. Assuming that the line is produced by reflection from the inner accretion disk, we infer an inner disk radius of \\sim25 Rg and a disk inclination of 35{\\deg} < i < 44{\\deg}.

  3. A time-resolved study of the broad-line region in blazar 3C 454.3

    Energy Technology Data Exchange (ETDEWEB)

    Isler, Jedidah C.; Urry, C. M.; Coppi, P.; Bailyn, C.; Buxton, M. [Department of Astronomy, Yale University, PO Box 208101, New Haven, CT 06520-8101 (United States); Chatterjee, R. [Department of Physics, Presidency University, 86/1 College Street, Kolkata 700073, WB (India); Fossati, G. [Department of Physics and Astronomy, Rice University, Houston, TX 77005 (United States); Bonning, E. W. [Quest University Canada, 3200 University Boulevard, Squamish, BC, V8B 0N8 (Canada); Maraschi, L., E-mail: jedidah.isler@yale.edu [INAF—Osservatorio Astronomico di Brera, V. Brera 28, I-20100 Milano (Italy)

    2013-12-20

    We present multi-epoch optical observations of the blazar 3C 454.3 (z = 0.859) from 2008 August through 2011 December, using the Small and Medium Aperture Research Telescope System Consortium 1.5 m + RCSpectrograph and 1.3 m + ANDICAM in Cerro Tololo, Chile. The spectra reveal that the broad emission lines Mg II, Hβ, and Hγ are far less variable than the optical or γ-ray continuum. Although the γ-rays varied by a factor of 100 above the EGRET era flux, the lines generally vary by a factor of two or less. Smaller variations in the γ-ray flux did not produce significant variation in any of the observed emission lines. Therefore, to first order, the ionizing flux from the disk changes only slowly during large variations of the jet. However, two exceptions in the response of the broad emission lines are reported during the largest γ-ray flares in 2009 December and 2010 November, when significant deviations from the mean line flux in Hγ and Mg II were observed. Hγ showed a maximum 3σ and 4σ deviation in each flare, respectively, corresponding to a factor of 1.7 and 2.5 increase in flux. Mg II showed a 2σ deviation in both flares; no variation was detected in Hβ during either flare. These significant deviations from the mean line flux also coincide with 7 mm core ejections reported previously (Jorstad et al.). The correlation of the increased emission line flux with millimeter core ejections and γ-ray, optical, and ultraviolet flares suggests that the broad-line region extends beyond the γ-emitting region during the 2009 and 2010 flares.

  4. The analysis of the hydrogen broad Balmer line ratios: possible implications to the physical properties of the BLR of AGN

    CERN Document Server

    Ilic, D; La Mura, G; Ciroi, S; Rafanelli, P

    2012-01-01

    We analyze the ratios of the broad hydrogen Balmer emission lines (from H\\alpha to H\\epsilon) in the context of estimating the physical conditions in the broad line region (BLR) of active galactic nuclei (AGN). The Balmer emission lines are obtained in three ways: i) using photoionization models obtained by a spectral synthesis code CLOUDY; ii) calculated using the recombination theory for hydrogenic ions; iii) measured from the sample of observed spectra taken from the Sloan Digital Sky Survey database. We investigate the Balmer line ratios in the frame of the so called Boltzmann-plot (BP), analyzing physical conditions of the emitting plasma for which we could use the BP method. The BP considers the ratio of Balmer lines normalized to the atomic data of the corresponding line transition, and is in that way different from the Balmer decrement. We found that for a certain range of thermodynamic parameters, there are objects that follow the BP. These AGN may have a BLR consisting of mostly high density plasma.

  5. Active galactic nuclei at z~1.5: II. Black Hole Mass estimation by means of broad emission lines

    CERN Document Server

    Mejía-Restrepo, Julián E; Lira, Paulina; Netzer, Hagai; Capellupo, Daniel M

    2016-01-01

    This is the second in a series of papers aiming to test how the mass ($M_{\\rm BH}$), accretion rate ($\\dot{M}$) and spin ($a_{*}$) of super massive black holes (SMBHs) determine the observed properties of type-I active galactic nuclei (AGN). Our project utilizes a sample of 39 unobscured AGN at $z\\simeq1.55$ observed by VLT/X-shooter, selected to map a large range in $M_{\\rm BH}$ and $L/L_{\\rm edd}$ and covers the most prominent UV-optical (broad) emission lines, including H$\\alpha$, H$\\beta$, MgII, and CIV. This paper focuses on single-epoch, "virial" $M_{\\rm BH}$ determinations from broad emission lines and examines the implications of different continuum modeling approaches in line width measurements. We find that using a "local" power-law continuum instead of a physically-motivated thin disk continuum leads to only slight underestimation of the FWHM of the lines and the associated $M_{\\rm BH}\\left({\\rm FWHM}\\right)$. However, the line dispersion $\\sigma_{\\rm line}$ and associated $M_{\\rm BH}\\left(\\sigma_{...

  6. Elemental Abundances in the Broad Emission Line Region of Quasars at Redshifts larger than 4

    DEFF Research Database (Denmark)

    Dietrich, M.; Appenzeller, I.; Hamann, F.;

    2003-01-01

    We present observations of 11 high redshift quasars ($3.9 \\la z \\la 5.0$) observed with low spectral resolution in the restframe ultraviolet using FORS 1 at the VLT UT 1. The emission-line fluxes of strong permitted and intercombination ultraviolet emission lines are measured to estimate the chem......We present observations of 11 high redshift quasars ($3.9 \\la z \\la 5.0$) observed with low spectral resolution in the restframe ultraviolet using FORS 1 at the VLT UT 1. The emission-line fluxes of strong permitted and intercombination ultraviolet emission lines are measured to estimate...

  7. Broad band Transmission Performance over Residential Power Lines Employing VDSL2

    Directory of Open Access Journals (Sweden)

    Usha Rani K R

    2013-01-01

    Full Text Available Bridging and Transmission of VDSL2 broadband over power lines has received considerable attention recently to cater to broadband distribution within the premises of a residence. Power lines are fundamentally different from telephone lines both in topology and load impedance. Power lines have a thicker gauge and shorter straight lengths, apart from a large number of bridge taps (BT with inductive load terminations, which are not matched to line impedances. In this paper ABCD parameters of the individual sections are used to analyze the power line channel of upto 10 bridge taps over a 600 meter length. The noise profiles considered include periodic impulse noise which is predominant over power line sections, apart from AWGN. Tone loading profiles have been obtained using Discrete Multitone Transmission (DMT as in VDSL2 over a bandwidth of 30 MHz. This analysis points to the fact that lower Transmit PSD would suffice to match the rates achievable by traditional VDSL2 when bridge taps are open. However with inductive loads typical in residences, we recommend a two step approach of (a equipping existing VDSL2 modem front end hybrids with settable impedances that would approach a conjugate match of the loaded line along with (b capability to nominally increase the Transmit PSD and added subbands to achieve the desired rates in a seamless manner as in VDSL2.

  8. Two-Component Structure of the Hbeta Broad-Line Region in Quasars. I. Evidence from Spectral Principal Component Analysis

    CERN Document Server

    Hu, Chen; Ho, Luis C; Ferland, Gary J; Baldwin, Jack A; Wang, Ye

    2012-01-01

    We report on a spectral principal component analysis (SPCA) of a sample of 816 quasars, selected to have small Fe II velocity shifts with spectral coverage in the rest wavelength range 3500--5500 \\AA. The sample is explicitly designed to mitigate spurious effects on SPCA induced by Fe II velocity shifts. We improve the algorithm of SPCA in the literature and introduce a new quantity, \\emph{the fractional-contribution spectrum}, that effectively identifies the emission features encoded in each eigenspectrum. The first eigenspectrum clearly records the power-law continuum and very broad Balmer emission lines. Narrow emission lines dominate the second eigenspectrum. The third eigenspectrum represents the Fe II emission and a component of the Balmer lines with kinematically similar intermediate velocity widths. Correlations between the weights of the eigenspectra and parametric measurements of line strength and continuum slope confirm the above interpretation for the eigenspectra. Monte Carlo simulations demonstr...

  9. Chandra High Resolution Spectroscopy of the Circumnuclear Matter in the Broad Line Radio Galaxy, 3C 445

    Science.gov (United States)

    Reeves, J. N.; Gofford, J.; Braito, V.; Sambruna, R.

    2010-01-01

    We present evidence for X-ray line emitting and absorbing gas in the nucleus of the Broad-Line Radio Galaxy (BLRG), 3C445. A 200 ks Chandra LETG observation of 3C 445 reveals the presence of several highly ionized emission lines in the soft X-ray spectrum, primarily from the He and H-like ions of O, Ne, Mg and Si. Radiative recombination emission is detected from O VII and O VIII, indicating that the emitting gas is photoionized. The He-like emission appears to be resolved into forbidden and intercombination line components, which implies a high density of greater than 10(sup 10) cm(sup -3), while the lines are velocity broadened with a mean width of 2600 km s(sup -1). The density and widths of the ionized lines indicate an origin of the gas on sub-parsec scales in the Broad Line Region (BLR). The X-ray continuum of 3C 445 is heavily obscured by a photoionized absorber of column density N(sub H) = 2 x 10(sup 23) cm(sup -2) and ionization parameter log xi = 1.4 erg cm s(sup -1). However the view of the X-ray line emission is unobscured, which requires the absorber to be located at radii well within any parsec scale molecular torus. Instead we suggest that the X-ray absorber in 3C 445 may be associated with an outflowing, but clumpy accretion disk wind, with an observed outflow velocity of approximately 10000 km s(sup -1).

  10. Chandra High-resolution Spectroscopy of the Circumnuclear Matter in the Broad-line Radio Galaxy 3C 445

    Science.gov (United States)

    Reeves, J. N.; Gofford, J.; Braito, V.; Sambruna, R.

    2010-12-01

    We present evidence for X-ray line emitting and absorbing gas in the nucleus of the broad-line radio galaxy 3C 445. A 200 ks Chandra Low Energy Transmission Grating observation of 3C 445 reveals the presence of several highly ionized emission lines in the soft X-ray spectrum, primarily from the He- and H-like ions of O, Ne, Mg, and Si. Radiative recombination emission is detected from O VII and O VIII, indicating that the emitting gas is photoionized. The He-like emission appears to be resolved into forbidden and intercombination line components, which implies a high density of >1010 cm-3, while the oxygen lines are velocity broadened with a mean width of ~2600 km s-1 (FWHM). The density and widths of the ionized lines indicate an origin of the gas on sub-parsec scales in the broad-line region. The X-ray continuum of 3C 445 is heavily obscured either by a partial coverer or by a photoionized absorber of column density N H = 2 × 1023 cm-2 and ionization parameter log ξ = 1.4 erg cm s-1. However, the view of the X-ray line emission is unobscured, which requires the absorber to be located at radii well within any parsec-scale molecular torus. Instead we suggest that the X-ray absorber in 3C 445 may be associated with an outflowing but clumpy accretion disk wind, with an observed outflow velocity of ~10, 000 km s-1.

  11. Constraints on the broad line region from regularized linear inversion: Velocity-delay maps for five nearby active galactic nuclei

    CERN Document Server

    Skielboe, Andreas; Treu, Tommaso; Park, Daeseong; Barth, Aaron J; Bentz, Misty C

    2015-01-01

    Reverberation mapping probes the structure of the broad emission-line region (BLR) in active galactic nuclei (AGN). The radius of the BLR along with the virial velocity of the BLR gas can be used to measure the mass of the supermassive black hole. The main systematic uncertainty affecting reverberation mapping is the unknown structure of the BLR. We develop a new method for analysing reverberation mapping data based on regularized linear inversion (RLI) that includes statistical modelling of the AGN continuum light curves. This method enables fast, flexible, and robust calculation of velocity-resolved response maps to probe BLR structure. Contrary to other methods, RLI allows for negative response in the BLR, such as when some areas of the BLR respond in inverse proportion to a change in ionizing continuum luminosity. We present time delays, integrated response functions, and velocity-delay maps for the H{\\beta} broad emission line in five nearby AGN, as well as H{\\alpha} and H{\\gamma} broad emission lines in...

  12. Detection of faint broad emission lines in type 2 AGN: I. Near infrared observations and spectral fitting

    Science.gov (United States)

    Onori, F.; La Franca, F.; Ricci, F.; Brusa, M.; Sani, E.; Maiolino, R.; Bianchi, S.; Bongiorno, A.; Fiore, F.; Marconi, A.; Vignali, C.

    2016-09-01

    We present medium resolution near infrared spectroscopic observations of 41 obscured and intermediate class AGN (type 2, 1.9 and 1.8; AGN2) with redshift z ≲0.1, selected from the Swift/BAT 70-month catalogue. The observations have been carried out in the framework of a systematic study of the AGN2 near infrared spectral properties and have been executed using ISAAC/VLT, X-shooter/VLT and LUCI/LBT, reaching an average S/N ratio of ˜30 per resolution element. For those objects observed with X-shooter we also obtained simultaneous optical and UV spectroscopy. We have identified a component from the broad line region in 13 out of 41 AGN2, with FWHM >800 km s-1. We have verified that the detection of the broad line region components does not significantly depend on selection effects due to the quality of the spectra, the X-ray or near infrared fluxes, the orientation angle of the host galaxy or the hydrogen column density measured in the X-ray band. The average broad line region components found in AGN2 has a significantly (a factor 2) smaller FWHM if compared with a control sample of type 1 AGN.

  13. Detection of faint broad emission lines in type 2 AGN: I. Near infrared observations and spectral fitting

    CERN Document Server

    Onori, F; Ricci, F; Brusa, M; Sani, E; Maiolino, R; Bianchi, S; Bongiorno, A; Fiore, F; Marconi, A; Vignali, C

    2016-01-01

    We present medium resolution near infrared spectroscopic observations of 41 obscured and intermediate class AGN (type 2, 1.9 and 1.8; AGN2) with redshift $z \\lesssim$0.1, selected from the Swift/BAT 70-month catalogue. The observations have been carried out in the framework of a systematic study of the AGN2 near infrared spectral properties and have been executed using ISAAC/VLT, X-shooter/VLT and LUCI/LBT, reaching an average S/N ratio of $\\sim$30 per resolution element. For those objects observed with X-shooter we also obtained simultaneous optical and UV spectroscopy. We have identified a component from the broad line region in 13 out of 41 AGN2, with FWHM ${\\rm > 800 }$ km/s. We have verified that the detection of the broad line region components does not significantly depend on selection effects due to the quality of the spectra, the X-ray or near infrared fluxes, the orientation angle of the host galaxy or the hydrogen column density measured in the X-ray band. The average broad line region components f...

  14. Selection of common bean lines with high grain yield and high grain calcium and iron concentrations

    Directory of Open Access Journals (Sweden)

    Nerinéia Dalfollo Ribeiro

    2014-02-01

    Full Text Available Genetic improvement of common bean nutritional quality has advantages in marketing and can contribute to society as a food source. The objective of this study was to evaluate the genetic variability for grain yield, calcium and iron concentrations in grains of inbred common bean lines obtained by different breeding methods. For this, 136 F7 inbred lines were obtained using the Pedigree method and 136 F7 inbred lines were obtained using the Single-Seed Descent (SSD method. The lines showed genetic variability for grain yield, and concentrations of calcium and iron independently of the method of advancing segregating populations. The Pedigree method allows obtaining a greater number of lines with high grain yield. Selection using the SSD method allows the identification of a larger number of lines with high concentrations of calcium and iron in grains. Weak negative correlations were found between grain yield and calcium concentration (r = -0.0994 and grain yield and iron concentration (r = -0.3926. Several lines show genetic superiority for grain yield and concentrations of calcium and iron in grains and their selection can result in new common bean cultivars with high nutritional quality.

  15. A Revised Broad-line Region Radius and Black Hole Mass for the Narrow-line Seyfert 1 NGC 4051

    DEFF Research Database (Denmark)

    Denney, K. D.; Watson, L. C.; Peterson, B. M.;

    2009-01-01

    ) radius and the optical continuum luminosity—the R BLR-L relationship. Our new measurements of the lag time between variations in the continuum and Hß emission line made from spectroscopic monitoring of NGC 4051 lead to a measured BLR radius of R BLR = 1.87+0.54 -0.50 light days and black hole mass of M...

  16. TWO-COMPONENT STRUCTURE OF THE Hβ BROAD-LINE REGION IN QUASARS. I. EVIDENCE FROM SPECTRAL PRINCIPAL COMPONENT ANALYSIS

    International Nuclear Information System (INIS)

    We report on a spectral principal component analysis (SPCA) of a sample of 816 quasars, selected to have small Fe II velocity shifts with spectral coverage in the rest wavelength range 3500-5500 Å. The sample is explicitly designed to mitigate spurious effects on SPCA induced by Fe II velocity shifts. We improve the algorithm of SPCA in the literature and introduce a new quantity, the fractional-contribution spectrum, that effectively identifies the emission features encoded in each eigenspectrum. The first eigenspectrum clearly records the power-law continuum and very broad Balmer emission lines. Narrow emission lines dominate the second eigenspectrum. The third eigenspectrum represents the Fe II emission and a component of the Balmer lines with kinematically similar intermediate-velocity widths. Correlations between the weights of the eigenspectra and parametric measurements of line strength and continuum slope confirm the above interpretation for the eigenspectra. Monte Carlo simulations demonstrate the validity of our method to recognize cross talk in SPCA and firmly rule out a single-component model for broad Hβ. We also present the results of SPCA for four other samples that contain quasars in bins of larger Fe II velocity shift; similar eigenspectra are obtained. We propose that the Hβ-emitting region has two kinematically distinct components: one with very large velocities whose strength correlates with the continuum shape and another with more modest, intermediate velocities that is closely coupled to the gas that gives rise to Fe II emission.

  17. Two-component Structure of the Hβ Broad-line Region in Quasars. I. Evidence from Spectral Principal Component Analysis

    Science.gov (United States)

    Hu, Chen; Wang, Jian-Min; Ho, Luis C.; Ferland, Gary J.; Baldwin, Jack A.; Wang, Ye

    2012-12-01

    We report on a spectral principal component analysis (SPCA) of a sample of 816 quasars, selected to have small Fe II velocity shifts with spectral coverage in the rest wavelength range 3500-5500 Å. The sample is explicitly designed to mitigate spurious effects on SPCA induced by Fe II velocity shifts. We improve the algorithm of SPCA in the literature and introduce a new quantity, the fractional-contribution spectrum, that effectively identifies the emission features encoded in each eigenspectrum. The first eigenspectrum clearly records the power-law continuum and very broad Balmer emission lines. Narrow emission lines dominate the second eigenspectrum. The third eigenspectrum represents the Fe II emission and a component of the Balmer lines with kinematically similar intermediate-velocity widths. Correlations between the weights of the eigenspectra and parametric measurements of line strength and continuum slope confirm the above interpretation for the eigenspectra. Monte Carlo simulations demonstrate the validity of our method to recognize cross talk in SPCA and firmly rule out a single-component model for broad Hβ. We also present the results of SPCA for four other samples that contain quasars in bins of larger Fe II velocity shift; similar eigenspectra are obtained. We propose that the Hβ-emitting region has two kinematically distinct components: one with very large velocities whose strength correlates with the continuum shape and another with more modest, intermediate velocities that is closely coupled to the gas that gives rise to Fe II emission.

  18. On The Formation Of Multiple Absorption Troughs In Broad Absorption Line QSOs

    CERN Document Server

    Pereyra, Nicolas A

    2013-01-01

    We present theoretical CIV 1548,1550 absorption line profiles for QSOs calculated assuming the accretion disk wind (ADW) scenario. The results suggest that the multiple absorption troughs seen in many QSOs may be due to the discontinuities in the ion balance of the wind (caused by X-rays), rather than discontinuities in the density/velocity structure. The profiles are calculated from a 2.5D time-dependent hydrodynamic simulation of a line-driven disk wind for a typical QSO black hole mass, a typical QSO luminosity, and for a standard Shakura-Sunyaev disk. We include the effects of ionizing X-rays originating from within the inner disk radius by assuming that the wind is shielded from the X-rays from a certain viewing angle up to 90o ("edge on"). In the shielded region we assume constant ionization equilibrium, and thus constant line-force parameters. In the non-shielded region we assume that both the line-force and the C+3 populations are nonexistent. The model, at viewing angles close to the angle that separ...

  19. The Structure of the Broad Line Region in AGN: I. Reconstructed Velocity-Delay Maps

    CERN Document Server

    Grier, C J; Horne, Keith; Bentz, M C; Pogge, R W; Denney, K D; De Rosa, G; Martini, Paul; Kochanek, C S; Zu, Y; Shappee, B; Siverd, R; Beatty, T G; Sergeev, S G; Kaspi, S; Salvo, C Araya; Bird, J C; Bord, D J; Borman, G A; Che, X; Chen, C; Cohen, S A; Dietrich, M; Doroshenko, V T; Efimov, Yu S; Free, N; Ginsburg, I; Henderson, C B; King, A L; Mogren, K; Molina, M; Mosquera, A M; Nazarov, S V; Okhmat, D N; Pejcha, O; Rafter, S; Shields, J C; Skowron, J; Szczygiel, D M; Valluri, M; van Saders, J L

    2012-01-01

    We present velocity-resolved reverberation results for five active galactic nuclei. We recovered velocity-delay maps using the maximum-entropy method for four objects: Mrk 335, Mrk 1501, 3C120, and PG2130+099. For the fifth, Mrk 6, we were only able to measure mean time delays in different velocity bins of the H\\beta\\ emission line, but see tentative evidence of combined virial motion and infalling gas. The four velocity-delay maps show unique dynamical signatures for each object. For 3C120, the Balmer lines show kinematic signatures consistent with both an inclined disk and infalling gas, but the HeII 4686 emission line is suggestive only of inflow. The Balmer lines in Mrk 335, Mrk 1501, and PG 2130+099 show signs of infalling gas, but the HeII emission in Mrk 335 is consistent with an inclined disk. The maps for 3C120 and Mrk 335 are two of the most clearly defined velocity-delay maps to date. These maps constitute a large increase in the number of objects for which we have resolved velocity-delay maps and ...

  20. Convective shifts of iron lines in the spectrum of the solar photosphere

    CERN Document Server

    Sheminova, V A

    2010-01-01

    The influence of the convective structure of the solar photosphere on the shifts of spectral lines of iron was studied. Line profiles in the visible and infrared spectrum were synthesized with the use of 2-D time-dependent hydrodynamic solar model atmospheres. The dependence of line shifts on excitation potential, wavelength, and line strength was analyzed, along with the depression contribution functions. The line shifts were found to depend on the location of the line formation region in convective cells and the difference between the line depression contributions from granules and intergranular lanes. In visible spectrum the weak and moderate lines are formed deep in the photosphere. Their effective line formation region is located in the central parts of granules, which make the major contribution to the absorption of spatially unresolved lines. The cores of strong lines are formed in upper photospheric layers where is formed reversed granulation due to convection reversal and physical conditions change d...

  1. Emission Signatures from Sub-parsec Binary Supermassive Black Holes. I. Diagnostic Power of Broad Emission Lines

    Science.gov (United States)

    Nguyen, Khai; Bogdanović, Tamara

    2016-09-01

    Motivated by advances in observational searches for sub-parsec supermassive black hole binaries (SBHBs) made in the past few years, we develop a semi-analytic model to describe spectral emission-line signatures of these systems. The goal of this study is to aid the interpretation of spectroscopic searches for binaries and to help test one of the leading models of binary accretion flows in the literature: SBHB in a circumbinary disk. In this work, we present the methodology and a comparison of the preliminary model with the data. We model SBHB accretion flows as a set of three accretion disks: two mini-disks that are gravitationally bound to the individual black holes and a circumbinary disk. Given a physically motivated parameter space occupied by sub-parsec SBHBs, we calculate a synthetic database of nearly 15 million broad optical emission-line profiles and explore the dependence of the profile shapes on characteristic properties of SBHBs. We find that the modeled profiles show distinct statistical properties as a function of the semimajor axis, mass ratio, eccentricity of the binary, and the degree of alignment of the triple disk system. This suggests that the broad emission-line profiles from SBHB systems can in principle be used to infer the distribution of these parameters and as such merit further investigation. Calculated profiles are more morphologically heterogeneous than the broad emission lines in observed SBHB candidates and we discuss improved treatment of radiative transfer effects, which will allow a direct statistical comparison of the two groups.

  2. On the relativistic iron line and soft excess in the Seyfert 1 galaxy Markarian 335

    CERN Document Server

    O'Neill, Paul M; Cappi, Massimo; Longinotti, Anna Lia; Sim, Stuart A

    2007-01-01

    We report on a 133 ks XMM-Newton observation of the Seyfert 1 galaxy Markarian 335. The 0.4-12 keV spectrum contains an underlying power law continuum, a soft excess below 2 keV, and a double-peaked iron emission feature in the 6-7 keV range. We investigate the possibility that the double-peaked emission might represent the characteristic signature of the accretion disc. Detailed investigations show that a moderately broad, accretion disc line is most likely present, but that the peaks may be owing to narrower components from more distant material. The peaks at 6.4 and 7 keV can be identified, respectively, with the molecular torus in active galactic nucleus unification schemes, and very highly ionized, optically thin gas filling the torus. The X-ray variability spectra on both long (~100 ks) and short (~1 ks) timescales disfavour the recent suggestion that the soft excess is an artifact of variable, moderately ionized absorption.

  3. Eddington ratio Distribution of X-ray selected broad-line AGNs at 1.0

    CERN Document Server

    Suh, Hyewon; Steinhardt, Charles; Silverman, John D; Schramm, Malte

    2015-01-01

    We investigate the Eddington ratio distribution of X-ray selected broad-line active galactic nuclei (AGN) in the redshift range 1.0broad-line AGNs in the Chandra Deep Field-South (CDF-S), Extended Chandra Deep Field-South (E-CDF-S), and the XMM-Newton Lockman Hole (XMM-LH) surveys. AGNs with similar black hole masses show a broad range of AGN bolometric luminosities, which are calculated from X-ray luminosities, indicating that the accretion rate of black holes is widely distributed. We find that a substantial fraction of massive black holes accreting significantly below the Eddington limit at z~2, in contrast to what is generally found for luminous AGNs at high redshift. Our analysis of observational selection biases indicates that the "AGN cosmic downsizing" phenomenon can be simply explained by the strong evolution of the co-moving number density at the b...

  4. Echo mappping of the broad line region of agns a critical appraisal

    CERN Document Server

    Maoz, D

    1994-01-01

    The results of recent AGN monitoring campaigns confirm the ``big picture'' of the echo paradigm, but the details of the emission-line light curves cannot be accurately reproduced with only the simplest assumptions, some of which must be invalid. I discuss possible solutions. I present some preliminary optical light curves from Wise Observatory for NGC 4151 during the December 1993 multi-satellite campaign. The optical data show a continuity with the complex behavior observed in the IUE data, and may explain the peculiarities in emission-line response seen in this and other AGNs. I review some recent results on quasar emission line variability from the Steward-Wise PG quasar monitoring program, which allow extension of the observed AGN BLR Radius--Luminosity relation to higher luminosities than previously feasible. Agreement with the expected R\\propto L^{1/2} relation is suggested. Finally, I criticize the trend to attribute significance to the details of transfer functions recovered by inversion techniques. I...

  5. The complex circumnuclear environment of the broad-line radio galaxy 3C 390.3 revealed by Chandra HETG

    CERN Document Server

    Tombesi, F; Kallman, T; Reynolds, C S; Mushotzky, R F; Braito, V; Behar, E; Leutenegger, M A; Cappi, M

    2016-01-01

    We present the first high spectral resolution X-ray observation of the broad-line radio galaxy 3C 390.3 obtained with the high energy transmission grating (HETG) spectrometer on board the Chandra X-ray Observatory. The spectrum shows complex emission and absorption features in both the soft X-rays and Fe K band. We detect emission and absorption lines in the energy range between E = 700-1000 eV associated with ionized Fe L transitions (Fe XVII-XX). An emission line at the energy of E=6.4 keV consistent with the Fe K\\alpha is also observed. Our best-fit model requires at least three different components: (i) a hot emission component likely associated with the hot interstellar medium in this elliptical galaxy with temperature kT=0.5+/-0.1 keV; (ii) a warm absorber with ionization parameter log\\xi=2.3+/-0.5 erg s^{-1} cm, column density logN_H=20.7+/-0.1 cm^{-2}, and outflow velocity of v_{out}<150 km s^{-1}; (iii) a lowly ionized reflection component in the Fe K band likely associated with the optical broad ...

  6. Testing the Kerr Nature of Black Hole Candidates Using Iron Line Spectra in the CPR Framework

    Science.gov (United States)

    Jiang, Jiachen; Bambi, Cosimo; Steiner, James F.

    2015-10-01

    The ironline commonly observed in the X-ray spectrum of both stellar-mass and supermassive black hole (BH) candidates originates from X-ray fluorescence of the inner accretion disk. Accordingly, it can be used to map the spacetime geometry around these objects. In this paper, we extend previous work using the ironline to test the Kerr BH hypothesis. We adopt the Cardoso-Pani-Rico parametrization and we test the possibility of constraining possible deviations from the Kerr solution that can be obtained from observations across the range of BH spins and inclination angles. We confirm previous claims that the ironline is potentially a quite powerful probe for testing the Kerr metric given sufficiently high quality data and with systematics under control, especially in the case of fast-rotating BHs and high inclination angles since both conditions serve to maximize relativistic effects. We find that some geometric perturbations from Kerr geometry manifest more strongly in the iron line profile than others. While the perturbation parameter {ɛ }3t can be well constrained by the iron line profile, an orthogonal data set is necessary to constrain departures from Kerr geometry in {ɛ }3r.

  7. The Corona of the Broad-Line Radio Galaxy 3C 390.3

    CERN Document Server

    Lohfink, Anne; Tombesi, Francesco; Walton, Dominic; Balokovic, Mislav; Zoghbi, Abdu; Ballantyne, David; Boggs, Steven; Christensen, Finn; Craig, William; Fabian, Andrew; Hailey, Charles; Harrison, Fiona; King, Ashley; Madejski, Greg; Matt, Giorgio; Reynolds, Christopher; Stern, Daniel; Ursini, Francesco; Zhang, William

    2015-01-01

    We present the results from a joint Suzaku/NuSTAR broad-band spectral analysis of 3C 390.3. The high quality data enables us to clearly separate the primary continuum from the reprocessed components allowing us to detect a high energy spectral cut-off ($E_\\text{cut}=117_{-14}^{+18}$ keV), and to place constraints on the Comptonization parameters of the primary continuum for the first time. The hard over soft compactness is 69$_{-24}^{+124}$ and the optical depth 4.1$_{-3.6}^{+0.5}$, this leads to an electron temperature of $30_{-8}^{+32}$ keV. Expanding our study of the Comptonization spectrum to the optical/UV by studying the simultaneous Swift-UVOT data, we find indications that the compactness of the corona allows only a small fraction of the total UV/optical flux to be Comptonized. Our analysis of the reprocessed emission show that 3C 390.3 only has a small amount of reflection (R~0.3), and of that the vast majority is from distant neutral matter. However we also discover a soft X-ray excess in the source...

  8. Broad-Line Reverberation in the Kepler-Field Seyfert Galaxy Zw 229-015

    CERN Document Server

    Barth, A J; Malkan, M A; Filippenko, A V; Li, W; Gorjian, V; Joner, M D; Bennert, V N; Botyanszki, J; Cenko, S B; Childress, M; Choi, J; Comerford, J M; Cucciara, A; da Silva, R; Duchene, G; Fumagalli, M; Ganeshalingam, M; Gates, E L; Gerke, B F; Griffith, C V; Harris, C; Hintz, E G; Hsiao, E; Kandrashoff, M T; Keel, W C; Kirkman, D; Kleiser, I K W; Laney, C D; Lee, J; Lopez, L; Lowe, T B; Moody, J W; Morton, A; Nierenberg, A M; Nugent, P; Pancoast, A; Rex, J; Rich, R M; Silverman, J M; Smith, G H; Sonnenfeld, A; Suzuki, N; Tytler, D; Walsh, J L; Woo, J -H; Yang, Y; Zeisse, C

    2011-01-01

    The Seyfert 1 galaxy Zw 229-015 is among the brightest active galaxies being monitored by the Kepler mission. In order to determine the black hole mass in Zw 229-015 from H-beta reverberation mapping, we have carried out nightly observations with the Kast Spectrograph at the Lick 3m telescope during the dark runs from June through December 2010, obtaining 54 spectroscopic observations in total. We have also obtained nightly V-band imaging with the Katzman Automatic Imaging Telescope at Lick Observatory and with the 0.9m telescope at the Brigham Young University West Mountain Observatory over the same period. We detect strong variability in the source, which exhibited more than a factor of 2 change in broad H-beta flux. From cross-correlation measurements, we find that the H-beta light curve has a rest-frame lag of 3.86(+0.69,-0.90) days with respect to the V-band continuum variations. We also measure reverberation lags for H-alpha and H-gamma and find an upper limit to the H-delta lag. Combining the H-beta la...

  9. Discovery of ultra-fast outflows in a sample of Broad Line Radio Galaxies observed with Suzaku

    CERN Document Server

    Tombesi, F; Reeves, J N; Braito, V; Ballo, L; Gofford, J; Cappi, M; Mushotzky, R F

    2010-01-01

    We present the results of a uniform and systematic search for blue-shifted Fe K absorption lines in the X-ray spectra of five bright Broad-Line Radio Galaxies (BLRGs) observed with Suzaku. We detect, for the first time at X-rays in radio-loud AGN, several absorption lines at energies greater than 7 keV in three out of five sources, namely 3C 111, 3C 120 and 3C 390.3. The lines are detected with high significance according to both the F-test and extensive Monte Carlo simulations. Their likely interpretation as blue-shifted Fe XXV and Fe XXVI K-shell resonance lines implies an origin from highly ionized gas outflowing with mildly relativistic velocities, in the range 0.04-0.15c. A fit with specific photo-ionization models gives ionization parameters in the range log_xi~4-5.6 and column densities of N_H~10^22-10^23 cm^-2. These characteristics are very similar to those of the Ultra-Fast Outflows (UFOs) previously observed in radio-quiet AGN. Their estimated location within ~0.01-0.3pc from the central super-mass...

  10. Broad Balmer Absorption Line Variability: Evidence of Gas Transverse Motion in the QSO SDSS J125942.80+121312.6

    Science.gov (United States)

    Shi, Xiheng; Zhou, Hongyan; Shu, Xinwen; Zhang, Shaohua; Ji, Tuo; Pan, Xiang; Sun, Luming; Zhao, Wen; Hao, Lei

    2016-03-01

    We report on the discovery of broad Balmer absorption lines variability in the QSO SDSS J125942.80+121312.6, based on the optical and near-infrared spectra taken from the SDSS-I, SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS), and TripleSpec observations over a timescale of 5.8 years in the QSO's rest-frame. The blueshifted absorption profile of Hβ shows a variation of more than 5σ at a high velocity portion (\\gt 3000 {km} {{{s}}}-1) of the trough. We perform a detailed analysis for the physical conditions of the absorber using Balmer lines as well as metastable He i and optical Fe ii absorptions (λ4233 from b4P5/2 level and λ5169 from a6S5/2) at the same velocity. These Fe ii lines are identified in the QSO spectra for the first time. According to the photoionization simulations, we estimate a gas density of n({{H}})≈ {10}9.1 {{cm}}-3 and a column density of {N}{col}({{H}})≈ {10}23 {{cm}}-2 for the BOSS data, but the model fails to predict the variations of ionic column densities between the SDSS and BOSS observations if changes in ionizing flux are assumed. We thus propose transverse motion of the absorbing gas being the cause of the observed broad Balmer absorption line variability. In fact, we find that the changes in covering factors of the absorber can well-reproduce all of the observed variations. The absorber is estimated ∼0.94 pc away from the central engine, which is where the outflow likely experiences deceleration due to the collision with the surrounding medium. This scheme is consistent with the argument that LoBAL QSOs may represent the transition from obscured star-forming galaxies to classic QSOs.

  11. Evershed flow observed in neutral and singly ionized iron lines

    Science.gov (United States)

    Khomenko, E.; Collados, M.; Shchukina, N.; Díaz, A.

    2015-12-01

    The amplitudes of the Evershed flow are measured using pairs of carefully selected Fe i and Fe ii spectral lines that are close in wavelength and registered simultaneously. A sunspot belonging to the NOAA 11582 group was scanned using the spectrograph of the German Vacuum Tower Telescope (Observatorio del Teide, Tenerife). Velocities were extracted from intensity profiles using the λ-meter technique. The formation heights of the observed spectral lines were calculated using semi-empirical models of a bright and dark penumbral filament taking into account the sunspot location at the limb. Our objective is to compare azimuthally averaged amplitudes of the Evershed flow extracted from neutral and ion lines. We find measurable differences in the radial component of the flow. All five pairs of lines show the same tendency; the flow measured from the Fe i lines has an amplitude that is a few hundred ms-1 larger than that of the Fe ii lines. This tendency is preserved at all photospheric heights and radial distances in the penumbra. We discuss the possible origin of this effect.

  12. Evershed flow observed in neutral and singly ionized iron lines

    CERN Document Server

    Khomenko, E; Shchukina, N; Diaz, A

    2015-01-01

    The amplitudes of the Evershed flow are measured using pairs of carefully selected FeI and FeII spectral lines located close in wavelength and registered simultaneously. A sunspot belonging to the NOAA 11582 group was scanned using the spectrograph of the German Vacuum Tower Telescope (Observatorio del Teide, Tenerife). Velocities were extracted from intensity profiles using the lambda-meter technique. The formation heights of the observed spectral lines were calculated using semi-empirical models of a bright and dark penumbral filament taking into account the sunspot location at the limb. Our objective is to compare azimuthally averaged amplitudes of the Evershed flow extracted from neutral and ion lines. We find measurable differences in the radial component of the flow. All five pairs of lines show the same tendency, with a few hundred m/s larger amplitude of the flow measured from FeI lines compared to FeII lines. This tendency is preserved at all photospheric heights and radial distances in the penumbra....

  13. Evaluation and Application of Two High-Iron Transgenic Rice Lines Expressing a Pea Ferritin Gene

    Institute of Scientific and Technical Information of China (English)

    YE Hong-xai; LI Mei; Guo Ze-jian; Shu Qing-yao; xu Xiao-hui; BAO Jin-song; SHEN Sheng-quan

    2008-01-01

    A totaI of 105 transgenic rice lines independently transformed with a pea ferritin gene (Fer)were previously obtained.After seven generations of selfing and β-glucuronidase(GUS)assisted selection,82 transgenic lines with stable agronomic traits were got.Among the 82 transgenic lines,two high-iron transgenic rice lines Fer34 and Fer65,with the iron contents in the milled rice being 4.82 and 3.46 times of that of the wild type Xiushui 11,respectively were identified.In the two transgenic lines,the exogenous Fer gene was highly expressed,and inherited as a single locus.The transgene had no negative effect on the agronomic traits of rice plant,other mineral nutritional components,appearance quailty and eating quailty of the milled rice,indicating that these two lines were elite high-iron breeding lines.Furthermore,the practical application and further studies facilitating utilization of the two elite breeding lines were discussed.

  14. SN 2010ay is a Luminous and Broad-lined Type Ic Supernova within a Low-metallicity Host Galaxy

    CERN Document Server

    Sanders, Nathan E; Valenti, S; Chomiuk, L; Berger, E; Smartt, S; Hurley, K; Barthelmy, S D; Chornock, R; Foley, R J; Levesque, E M; Narayan, G; Kirshner, R P; Botticella, M T; Briggs, M S; Connaughton, V; Terada, Y; Gehrels, N; Golenetskii, S; Mazets, E; Cline, T; von Kienlin, A; Boynton, W; Chambers, K C; Grav, T; Heasley, J N; Hodapp, K W; Jedicke, R; Kaiser, N; Kudritzki, R -P; Luppino, G A; Lupton, R H; Magnier, E A; Monet, D G; Morgan, J S; Onaka, P M; Price, P A; Stubbs, C W; Tonry, J L; Wainscoat, R J; Waterson, M F

    2011-01-01

    [abridged] We report on our serendipitous pre-discovery detection and detailed follow-up of the broad-lined Type Ic supernova SN 2010ay at z\\approx0.067 imaged by the Pan-STARRS1 3{\\pi} survey just \\sim3 days after explosion. We estimate the explosion date and the peak luminosity of the SN, MR\\approx-20.2 mag, significantly brighter than known GRB-SNe and one of the most luminous SNe Ic ever discovered. We measure the photospheric expansion velocity of the explosion, v_ph\\approx19.2x10^3 km/s at \\sim40 days after explosion. In comparison with other broad-lined SNe, the characteristic velocity of SN 2010ay is 2-5x higher and similar to the measurements for GRB-SNe at comparable epochs. Moreover the velocity declines two times slower than other SNe Ic-BL and GRB-SNe. Assuming that the optical emission is powered by radioactive decay, the peak magnitude implies the synthesis of an unusually large mass of 56 Ni, M_Ni=0.9+0.2 M_solar. Our modeling of the light-curve points to a total ejecta mass, Mej\\approx4.7M_so...

  15. The Lick AGN Monitoring Project: Broad-Line Region Radii and Black Hole Masses from Reverberation Mapping of Hbeta

    CERN Document Server

    Bentz, Misty C; Barth, Aaron J; Baliber, Nairn; Bennert, Nicola; Canalizo, Gabriela; Filippenko, Alexei V; Ganeshalingam, Mohan; Gates, Elinor L; Greene, Jenny E; Hidas, Marton G; Hiner, Kyle D; Lee, Nicholas; Li, Weidong; Malkan, Matthew A; Minezaki, Takeo; Sakata, Yu; Serduke, Frank J D; Silverman, Jeffrey M; Steele, Thea N; Stern, Daniel; Street, Rachel A; Thornton, Carol E; Treu, Tommaso; Wang, Xiaofeng; Woo, Jong-Hak; Yoshii, Yuzuru

    2009-01-01

    We have recently completed a 64-night spectroscopic monitoring campaign at the Lick Observatory 3-m Shane telescope with the aim of measuring the masses of the black holes in 12 nearby (z < 0.05) Seyfert 1 galaxies with expected masses in the range ~10^6-10^7 M_sun and also the well-studied nearby active galactic nucleus (AGN) NGC 5548. Nine of the objects in the sample (including NGC 5548) showed optical variability of sufficient strength during the monitoring campaign to allow for a time lag to be measured between the continuum fluctuations and the response to these fluctuations in the broad Hbeta emission. We present here the light curves for the objects in this sample and the subsequent Hbeta time lags for the nine objects where these measurements were possible. The Hbeta lag time is directly related to the size of the broad-line region, and by combining the lag time with the measured width of the Hbeta emission line in the variable part of the spectrum, we determine the virial mass of the central supe...

  16. Single-Epoch Black Hole Mass Estimators For Broad-Line Active Galactic Nuclei: Recalibrating Hbeta with A New Approach

    CERN Document Server

    Feng, Hua; Li, Hong

    2014-01-01

    Based on an updated Hbeta reverberation mapping (RM) sample of 44 nearby active galactic nuclei (AGN), we propose a novel approach for black hole (BH) mass estimation using two filtered luminosities computed from single-epoch (SE) AGN spectra around the Hbeta region. We found that the two optimal-filter luminosities extract virial information (size and virial velocity of the broad line region, BLR) from the spectra, justifying their usage in this empirical BH mass estimator. The major advantages of this new recipe over traditional SE BH mass estimators utilizing continuum luminosity and broad line width are: 1) it has a smaller intrinsic scatter of 0.28 dex calibrated against RM masses; 2) it is extremely simple to use in practice, without any need to decompose the spectrum; 3) it produces unambiguous and highly repeatable results even with low signal-to-noise spectra. The combination of the two luminosities can also cancel out, to some extent, systematic luminosity errors potentially introduced by uncertaint...

  17. The Black Hole-Bulge Relationship in Luminous Broad-Line Active Galactic Nuclei and Host Galaxies

    CERN Document Server

    Shen, J; Schneider, D P; Hall, P B

    2007-01-01

    We have measured the stellar velocity dispersions (\\sigma_*) and estimated the central black hole (BH) masses for over 900 broad-line active galactic nuclei (AGNs) observed with the Sloan Digital Sky Survey. The sample includes objects which have redshifts up to z=0.452, high quality spectra, and host galaxy spectra dominated by an early-type (bulge) component. The AGN and host galaxy spectral components were decomposed using an eigenspectrum technique. The BH masses (M_BH) were estimated from the AGN broad-line widths, and the velocity dispersions were measured from the stellar absorption spectra of the host galaxies. The range of black hole masses covered by the sample is approximately 10^6 < M_BH < 10^9 M_Sun. The host galaxy luminosity-velocity dispersion relationship follows the well-known Faber-Jackson relation for early-type galaxies, with a power-law slope 4.33+-0.21. The estimated BH masses are correlated with both the host luminosities (L_{H}) and the stellar velocity dispersions (\\sigma_*), s...

  18. Radio Properties of Low Redshift Broad Line Active Galactic Nuclei Including Multiple Component Radio Sources

    Science.gov (United States)

    Rafter, Stephen E.

    2010-01-01

    We present results on the radio properties of a low redshift (z FRIIs. From these data we find an FRI/FRII luminosity dividing line like that found by Fanaroff & Riley (1974), where we use our core-only sources as proxies for FRIs, and our multi-component sources for the FRIIs. We find a bimodal distribution for the radio loudness (R = L(radio)/L(opt)) where the lower radio luminosity core-only sources appear as a population separate from the multi-component extended sources, compared with no evidence for bimodality when just the core-only sources are used. We also find that a log(R) value of 1.75 is well suited to separate the FRIs from the FRIIs, and that the R bimodality seen here is really a manifestation of the FRI/FRII break originally found by Fanaroff & Riley (1974). We find modest trends in the radio loud fraction as a function of Eddington ratio and black hole mass, where the fraction of RL AGNs decreases with increasing Eddington ratio, and increases when the black hole mass is above 2 x 108 solar masses.

  19. Effect of a partial coverage of quasar broad-line regions by intervening H$_2$-bearing clouds

    CERN Document Server

    Ofengeim, Dmitrii; Ivanchik, Aleksandr; Kaminker, Aleksandr; Klimenko, Vyacheslav

    2015-01-01

    We consider the effect of a partial coverage of quasar broad-line regions (QSO BLRs) by intervening H$_2$-bearing clouds when a part of quasar (QSO) radiation passes by a cloud not taking part in formation of an absorption-line system in the QSO spectrum. That leads to modification of observable absorption line profiles and consequently to a bias in physical parameters derived from standard absorption line analysis. In application to the H$_2$ {absorption} systems the effect has been revealed in the analysis of H$_2$ absorption system in the spectrum of Q~1232+082 (Ivanchik et al. 2010, Balashev et al. 2011). We estimate a probability of the effect to be detected in QSO spectra. To do this we derive distribution of BLR sizes of high-z QSOs from Sloan Digital Sky Survey (SDSS) Data Release 9 (DR9) catalogue and assume different distributions of cloud sizes. We conclude that the low limit of the probability is about $11\\%$. The latest researches shows that about a fifth of observed H$_2$ absorption systems can ...

  20. Long term stability analysis of cast iron shaft linings after Coal Mine closure and flooding

    Energy Technology Data Exchange (ETDEWEB)

    Hadj-Hassen, F. [Ecole des Mines de Paris - CGES, 77 - Fontainebleau (France); Bienvenu, Y. [Ecole des Mines de Paris, CM, 91 - Evry (France); Noirel, J.F. [Charbonnages de France, DTN, 57 - Freyming Merlebach (France); Metz, M. [charbonnages de France, ESA, 57 - Freyming Merlebach (France)

    2005-07-01

    This paper presents the results of a study conducted to analyse the long term stability of the cast iron shaft lining after coal mine closure and flooding. The attention is mainly focused on the behaviour during the critical phase of flooding as well as the phase corresponding to the disappearance of the water pressure and the stabilization of the environment. This pluri-disciplinary study was conducted by a team combining specialists in rock mechanics who identified the main risks and the conditions of stability of the lining and specialists in metallurgy who studied the composition of the cast iron and its corrosion behaviour after exposure to mine water. (authors)

  1. The Variability of Hardness Ratio 1 observed by ROSAT:Narrow-Line Seyfert 1 Galaxies versus Broad-Line Seyfert 1 Galaxies

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    We examined the correlation between the ROSAT Hardness Ratio 1and Count Rates eight Narrow-line Seyfert 1 Galaxies (NLS1s) and 14 Broad-lineSeyfert1 Galaxies (BLS1s). We found that six of the NLS1s show a positive HR1-CTs correlation, and seven of the BLS1s, a negative correlation. The other twoNLS1s and seven BLS1s do not show any clear HR1-CTs correlation. Thus, thespectral behavior is statistically different for the NLS1s and BLS1s. The differentin NLS1s and weak in BLS1s, plus a power law component, common to both, whichsoftens with increasing flux.

  2. Discovery of Ultra-fast Outflows in a Sample of Broad-line Radio Galaxies Observed with Suzaku

    Science.gov (United States)

    Tombesi, F.; Sambruna, R. M.; Reeves, J. N.; Braito, V.; Ballo, L.; Gofford, J.; Cappi, M.; Mushotzky, R. F.

    2010-08-01

    We present the results of a uniform and systematic search for blueshifted Fe K absorption lines in the X-ray spectra of five bright broad-line radio galaxies observed with Suzaku. We detect, for the first time in radio-loud active galactic nuclei (AGNs) at X-rays, several absorption lines at energies greater than 7 keV in three out of five sources, namely, 3C 111, 3C 120, and 3C 390.3. The lines are detected with high significance according to both the F-test and extensive Monte Carlo simulations. Their likely interpretation as blueshifted Fe XXV and Fe XXVI K-shell resonance lines implies an origin from highly ionized gas outflowing with mildly relativistic velocities, in the range v ~= 0.04-0.15c. A fit with specific photoionization models gives ionization parameters in the range log ξ ~= 4-5.6 erg s-1 cm and column densities of N H ~= 1022-1023 cm-2. These characteristics are very similar to those of the ultra-fast outflows (UFOs) previously observed in radio-quiet AGNs. Their estimated location within ~0.01-0.3 pc of the central super-massive black hole suggests a likely origin related with accretion disk winds/outflows. Depending on the absorber covering fraction, the mass outflow rate of these UFOs can be comparable to the accretion rate and their kinetic power can correspond to a significant fraction of the bolometric luminosity and is comparable to their typical jet power. Therefore, these UFOs can play a significant role in the expected feedback from the AGN to the surrounding environment and can give us further clues on the relation between the accretion disk and the formation of winds/jets in both radio-quiet and radio-loud AGNs.

  3. Frequency lock of a dye laser emission on iron atomic line top

    International Nuclear Information System (INIS)

    The aim of this thesis is to realize a frequency lock of a dye laser emission on iron atomic line top. To reach that goal, the author first presents the calculation of atomic vapour density by means of laser absorption ratio measure and studies the dye laser working. It is then necessary to find a device giving the required precision on the frequency of the absorption line choosen. It is obtained thanks to the atomic line reconstitution by optogalvanic effect which gives the reference. Besides, the author presents the necessity of a laser emission power regulation which is obtained thanks to a device including an acoustic and optic modulator. A reliable and accurate captor is choosen and adjusted testing various hollow cathode lamps. The method to obtain the frequency lock of laser emission on iron atomic line top is described. (TEC). 18 refs., 64 figs

  4. SN 2010ay Is a Luminous and Broad-Lined Type Ic Supernova Within a Low-Metallicity Host Galaxy

    Science.gov (United States)

    Sanders, N. E.; Soderberg, A. M.; Valenti, S.; Foley, R. J.; Chornock, R.; Chomiuk, L.; Berger, E.; Smartt, S.; Hurley, K.; Barthelmy, S. D.; Levesque, E. M.; Narayan, G.; Botticella, M. T.; Briggs, M. S.; Connaughton, V.; Terada, Y.; Gehrels, N.; Golenetskii, S.; Mazets, E.; Cline, T.; von Kienlin, A.; Boynton, W.; Chambers, K. C.; Grav, T.; Heasley, J. N.

    2012-01-01

    We report on our serendipitous pre-discovery detection and follow-up observations of the broad-lined Type Ic supernova (SN Ic) 2010ay at z = 0.067 imaged by the Pan-STARRS1 3pi survey just approximately 4 days after explosion. The supernova (SN) had a peak luminosity, MR approx. -20.2 mag, significantly more luminous than known GRB-SNe and one of the most luminous SNe Ib/c ever discovered. The absorption velocity of SN 2010ay is v Si (is) approx. 19×10(exp 3) km s-1 at approximately 40 days after explosion, 2-5 times higher than other broad-lined SNe and similar to the GRB-SN 2010bh at comparable epochs. Moreover, the velocity declines approximately 2 times slower than other SNe Ic-BL and GRB-SNe. Assuming that the optical emission is powered by radioactive decay, the peak magnitude implies the synthesis of an unusually large mass of 56Ni, MNi = 0.9 solar mass. Applying scaling relations to the light curve, we estimate a total ejecta mass, Mej (is) approx. 4.7 solar mass, and total kinetic energy, EK (is) approx. 11 × 10(exp 51) erg. The ratio of MNi to Mej is approximately 2 times as large for SN 2010ay as typical GRB-SNe and may suggest an additional energy reservoir. The metallicity (log(O/H)PP04 + 12 = 8.19) of the explosion site within the host galaxy places SN 2010ay in the low-metallicity regime populated by GRB-SNe, and (is) approximately 0.5(0.2) dex lower than that typically measured for the host environments of normal (broad-lined) SNe Ic. We constrain any gamma-ray emission with E(gamma) (is) approximately less than 6 × 10(exp 48) erg (25-150 keV), and our deep radio follow-up observations with the Expanded Very Large Array rule out relativistic ejecta with energy E (is) approximately greater than 10(exp 48) erg. We therefore rule out the association of a relativistic outflow like those that accompanied SN 1998bw and traditional long-duration gamma-ray bursts (GRBs), but we place less-stringent constraints on a weak afterglow like that seen from XRF

  5. Broad Balmer Absorption Line Variability: Evidence of Gas Transverse Motion in the QSO SDSS J125942.80+121312.6

    CERN Document Server

    Shi, Xiheng; Shu, Xinwen; Zhang, Shaohua; Ji, Tuo; Pan, Xiang; Sun, Luming; Zhao, Wen; Hao, Lei

    2016-01-01

    We report on the discovery of broad Balmer absorption lines variability in the QSO SDSS J125942.80+121312.6, based on the optical and near-infrared spectra taken from the SDSS-I, SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS), and TripleSpec observations over a timescale of 5.8 years in the QSO's rest-frame. The blueshifted absorption profile of H$\\beta$ shows a variation of more than 5$\\sigma$ at a high velocity portion ($>3000\\ \\mathrm{km\\ s}^{-1}$) of the trough. We perform a detailed analysis for the physical conditions of the absorber using Balmer lines as well as metastable He I and optical Fe II absorptions ($\\lambda 4233$ from b$^4$P$_{5/2}$ level and $\\lambda 5169$ from a$^6$S$_{5/2}$) at the same velocity. These Fe II lines are identified in the QSO spectra for the first time. According to the photoionization simulations, we estimate a gas density of $n(\\mathrm{H})\\approx 10^{9.1}\\ \\mathrm{cm}^{-3}$ and a column density of $N_{\\mathrm{col}}(\\mathrm{H})\\approx 10^{23}\\ \\mathrm{cm}^{-2}$ for ...

  6. The case for cases B and C: intrinsic hydrogen line ratios of the broad-line region of active galactic nuclei, reddenings, and accretion disc sizes

    CERN Document Server

    Gaskell, C Martin

    2016-01-01

    Low-redshift active galactic nuclei (AGNs) with extremely blue optical spectral indices are shown to have a mean, velocity-averaged, broad-line H$\\alpha$/H$\\beta$ ratio of $\\thickapprox 2.72 \\pm 0.04$, consistent with the Baker-Menzel Case B value. Comparison of a wide range of properties of the very bluest AGNs with those of a luminosity-matched subset of the Dong et al. blue AGN sample indicates that the only difference is the internal reddening. Ultraviolet fluxes are brighter for the bluest AGNs by an amount consistent with the flat AGN reddening curve of Gaskell et al. (2004). The lack of a significant difference in the GALEX (FUV--NUV) colour index strongly rules out a steep SMC-like reddening curve and also argues against an intrinsically harder spectrum. For very blue AGNs the Ly$\\alpha$/H$\\beta$ ratio is also consistent with being the Case B value. The Case B ratios provide strong support for the self-shielded broad-line model of Gaskell, Klimek & Nazarova. It is proposed that the greatly enhance...

  7. Constraining UV continuum slopes of active galactic nuclei with cloudy models of broad-line region extreme-ultraviolet emission lines

    Energy Technology Data Exchange (ETDEWEB)

    Moloney, Joshua [CASA, Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, CO 80309 (United States); Michael Shull, J., E-mail: joshua.moloney@colorado.edu, E-mail: michael.shull@colorado.edu [Also at Institute of Astronomy, University of Cambridge, Cambridge CB3 0HA, UK. (United Kingdom)

    2014-10-01

    Understanding the composition and structure of the broad-line region (BLR) of active galactic nuclei (AGNs) is important for answering many outstanding questions in supermassive black hole evolution, galaxy evolution, and ionization of the intergalactic medium. We used single-epoch UV spectra from the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope to measure EUV emission-line fluxes from four individual AGNs with 0.49 ≤ z ≤ 0.64, two AGNs with 0.32 ≤ z ≤ 0.40, and a composite of 159 AGNs. With the CLOUDY photoionization code, we calculated emission-line fluxes from BLR clouds with a range of density, hydrogen ionizing flux, and incident continuum spectral indices. The photoionization grids were fit to the observations using single-component and locally optimally emitting cloud (LOC) models. The LOC models provide good fits to the measured fluxes, while the single-component models do not. The UV spectral indices preferred by our LOC models are consistent with those measured from COS spectra. EUV emission lines such as N IV λ765, O II λ833, and O III λ834 originate primarily from gas with electron temperatures between 37,000 K and 55,000 K. This gas is found in BLR clouds with high hydrogen densities (n {sub H} ≥ 10{sup 12} cm{sup –3}) and hydrogen ionizing photon fluxes (Φ{sub H} ≥ 10{sup 22} cm{sup –2} s{sup –1}).

  8. Multiwavelength campaign on Mrk 509 XV. A global modeling of the broad emission lines in the Optical, UV and X-ray bands

    CERN Document Server

    Costantini, E; Kaastra, J S; Bianchi, S; Branduardi-Raymont, G; Cappi, M; De Marco, B; Ebrero, J; Mehdipour, M; Petrucci, P -O; Paltani, S; Ponti, G; Steenbrugge, K C; Arav, N

    2016-01-01

    We model the broad emission lines present in the optical, UV and X-ray spectra of Mrk 509, a bright type 1 Seyfert galaxy. The broad lines were simultaneously observed during a large multiwavelength campaign, using the XMM-Newton-OM for the optical lines, HST-COS for the UV lines and XMM-Newton-RGS and Epic for the X-ray lines respectively. We also used FUSE archival data for the broad lines observed in the far-ultra-violet. The goal is to find a physical connection among the lines measured at different wavelengths and determine the size and the distance from the central source of the emitting gas components. We used the "Locally optimally emission Cloud" (LOC) model which interprets the emissivity of the broad line region (BLR) as regulated by powerlaw distributions of both gas density and distances from the central source. We find that one LOC component cannot model all the lines simultaneously. In particular, we find that the X-ray and UV lines likely may originate in the more internal part of the AGN, at ...

  9. Relation between the "Double-Hump" Behavior in the Radio Band and the Broad-Line Luminosity for Blazars

    Institute of Scientific and Technical Information of China (English)

    Zhao-Hua Xie; Hong Dai; Jian-Ming Hao; Lei-Ming Du; Xiong Zhang

    2007-01-01

    The physics behind the spectral energy distribution (SED) of blazars remains open.We assembled 36 blazars to tackle the factors that control their SED. Now, many blazar spectra have the "double hump" feature in the radio and far-IR frequencies. For these a parameter,△, is created to characterize the behavior of the SED. We found a significant correlation between the broad-line luminosity (LBLR) and △. Because LBLR is an indicator of the accreting power of the source in blazars, we derived a linear correlation,△∝ (M)1/3. 18, which suggests that the SED of blazars may depend on the accretion rate, like that of BL Lac objects. We also found a significant correlation between (m) and△ for a sample of 11 blazars (out of one of 36)with available black hole masses. This implies the Eddington accretion ratio may influence the shape of the SED of blazars.

  10. Interaction Between The Broad-lined Type Ic Supernova 2012ap and Carriers of Diffuse Interstellar Bands

    CERN Document Server

    Milisavljevic, D; Crabtree, K N; Foster, J B; Soderberg, A M; Fesen, R A; Parrent, J T; Sanders, N E; Drout, M R; Kamble, A; Chakraborti, S; Pickering, T E; Cenko, S B; Silverman, J M; Filippenko, A V; Kirshner, R P; Mazzali, P; Maeda, K; Marion, G H; Vinko, J; Wheeler, J C

    2014-01-01

    The diffuse interstellar bands (DIBs) are absorption features observed in optical and near-infrared spectra that are thought to be associated with carbon-rich polyatomic molecules in interstellar gas. However, because the central wavelengths of these bands do not correspond with electronic transitions of any known atomic or molecular species, their nature has remained uncertain since their discovery almost a century ago. Here we report on unusually strong DIBs in optical spectra of the broad-lined Type Ic supernova SN 2012ap that exhibit changes in equivalent width over short (~30 days) timescales. The 4428 and 6283 Angstrom DIB features get weaker with time, whereas the 5780 Angstrom feature shows a marginal increase. These nonuniform changes suggest that the supernova is interacting with a nearby source of the DIBs and that the DIB carriers possess high ionization potentials, such as small cations or charged fullerenes. We conclude that moderate-resolution spectra of supernovae with DIB absorptions obtained...

  11. Formation of Turbulent Cones in Accretion Disk Outflows and Application to Broad Line Regions of Active Galactic Nuclei

    CERN Document Server

    Poludnenko, A Y; Frank, A

    2002-01-01

    We consider the stability of an accretion disk wind to cloud formation when subject to a central radiation force. For a vertical launch velocity profile that is Keplerian or flatter and the presence of a significant radiation pressure, the wind flow streamlines cross in a conical layer. We argue that such regions are highly unstable, and are natural sites for supersonic turbulence and, consequently, density compressions. We suggest that combined with thermal instability these will all conspire to produce clouds. Such clouds can exist in dynamical equilibrium, constantly dissipating and reforming. As long as there is an inner truncation radius to the wind, our model emerges with a biconical structure similar to that inferred by Elvis (2000) for the broad line region (BLR) of active galactic nuclei (AGN). Our results may also apply to other disk-wind systems.

  12. The broad line type Ic supernova SN 2007ru: Adding to the diversity of type Ic supernovae

    CERN Document Server

    Sahu, D K; Anupama, G C; Gurugubelli, Uday K; Nomoto, Ken'ichi

    2008-01-01

    Photometric and spectral evolution of the type Ic supernova SN 2007ru during the first 3 months are presented. The spectra show broad spectral features due to very high expansion velocity, normally seen in hypernovae. The photospheric velocity is higher than other type Ic supernovae. It is lower than SN 1998bw at $\\sim$ 8 days after the explosion, but is comparable at later epochs. The light curve evolution of SN 2007ru indicates a fast rise time of 8$\\pm$3 days to $B$ band maximum and post-maximum decline more rapidly than other broad-line type Ic supernovae.With an absolute $V$ magnitude of -19.10, SN 2007ru is comparable in brightness with SN 1998bw and lies at the brighter end of the observed type Ic supernovae. The mass of \\Nifs is estimated to be $\\sim 0.4\\Msun$. The fast rise and decline of the light curve and the high expansion velocity suggest that SN 2007ru is an explosion with a high kinetic energy/ejecta mass ratio ($E_{\\rm K}/M_{\\rm {ej}}$). This adds to the diversity of type Ic supernovae.

  13. Discovery of Broad Molecular lines and of Shocked Molecular Hydrogen from the Supernova Remnant G357.7+0.3: HHSMT, APEX, Spitzer and SOFIA Observations

    CERN Document Server

    Rho, J; Hewitt, J; Andersen, M; Reach, W T; Guesten, R

    2016-01-01

    We report a discovery of shocked gas from the supernova remnant (SNR) G357.7+0.3. Our millimeter and submillimeter observations reveal broad molecular lines of CO(2-1), CO(3-2), CO(4-3), 13CO (2-1) and 13CO (3-2), HCO^+ and HCN using HHSMT, Arizona 12-Meter Telescope, APEX and MOPRA Telescope. The widths of the broad lines are 15-30 kms, and the detection of such broad lines is unambiguous, dynamic evidence showing that the SNR G357.7+0.3 is interacting with molecular clouds. The broad lines appear in extended regions (>4.5'x5'). We also present detection of shocked H2 emission in mid-infrared but lacking ionic lines using the Spitzer IRS observations to map a few arcmin area. The H2 excitation diagram shows a best-fit with a two-temperature LTE model with the temperatures of ~200 and 660 K. We observed [C II] at 158um and high-J CO(11-10) with the GREAT on SOFIA. The GREAT spectrum of [C II], a 3 sigma detection, shows a broad line profile with a width of 15.7 km/s that is similar to those of broad CO molecu...

  14. A three-dimensional hydrodynamical line profile analysis of iron lines and barium isotopes in HD140283

    CERN Document Server

    Gallagher, A J; Ryan, S G; Aoki, W

    2015-01-01

    Heavy-elements, i.e. those beyond the iron peak, mostly form via two neutron capture processes: the s- and r-process. Metal-poor stars should contain fewer isotopes that form via the s-process, according to currently accepted theory. It has been shown in several investigations that theory and observation do not agree well, raising questions on the validity of either the methodology or the theory. We analyse the metal-poor star HD140283, for which we have a high quality spectrum. We test whether a 3D LTE stellar atmosphere and spectrum synthesis code permits a more reliable analysis of the iron abundance and barium isotope ratio than a 1D LTE analysis. Using 3D model atmospheres, we examine 91 iron lines of varying strength and formation depth. This provides us with the star's rotational speed. With this, we model the barium isotope ratio by exploiting the hyperfine structure of the singly ionised 4554 resonance line, and study the impact of the uncertainties in the stellar parameters. HD140283's vsini = 1.65 ...

  15. Emission Signatures from Sub-parsec Binary Supermassive Black Holes I: Diagnostic Power of Broad Emission Lines

    CERN Document Server

    Nguyen, Khai

    2016-01-01

    Motivated by advances in observational searches for sub-parsec supermassive black hole binaries (SBHBs) made in the past few years we develop a semi-analytic model to describe spectral emission line signatures of these systems. The goal of this study is to aid the interpretation of spectroscopic searches for binaries and help test one of the leading models of binary accretion flows in the literature: SBHB in a circumbinary disk. In this work we present the methodology and a comparison of the preliminary model with the data. We model SBHB accretion flows as a set of three accretion disks: two mini-disks that are gravitationally bound to the individual black holes and a circumbinary disk. Given a physically motivated parameter space occupied by sub-parsec SBHBs, we calculate a synthetic database of nearly 15 million broad optical emission line profiles and explore the dependence of the profile shapes on characteristic properties of SBHBs. We find that the modeled profiles show distinct statistical properties as...

  16. The optical and radio properties of a low-redshift sample of broad-lined active galactic nuclei

    Science.gov (United States)

    Rafter, Stephen E.

    2010-11-01

    The question as to whether the distribution of radio loudness in active galactic nuclei (AGN) is actually bimodal has been discussed extensively in the literature. Furthermore, there have been claims that radio loudness depends on black hole mass (MBH) and Eddington ratio (Lbol/L Edd). We investigate these claims using the low redshift broad line AGN sample of Greene & Ho (2007), which consists of 8434 objects at z search for extended emission in FIRST that can be positively associated with the optical counterparts and find 51 out of the 846 previously detected core sources have extended emission that must be taken into account when calculating the total radio luminosity. Further, we find an additional 12 objects that have extended radio emission but no detectable radio core and have classic FR II type morphologies. Using these data, the question of radio bimodality and the dependence of radio-loudness on physical parameters are investigated for different subsets of the total sample. We find modest trends in the radio-loud fraction as a function of MBH and Lbol/LEdd, where the fraction of RL AGN increases for the largest MBH group and decreases with increasing Lbol/LEdd. With extended emission taken into account, we find strong evidence for a bimodal distribution in R, where the lower radio luminosity core-only sources appear as a population separate from the extended sources with a dividing line at log(R) ≈ 1.75. This dividing line is interesting in that it requires the radio luminosity to be 50 times the optical luminosity, ensuring that these are indeed the most RL AGN, which may have different or extreme physical conditions in their central engines when compared to the more numerous radio quiet AGN in this sample. Index words. Active galaxies, Radio galaxies.

  17. Iron

    Science.gov (United States)

    Iron is a mineral that our bodies need for many functions. For example, iron is part of hemoglobin, a protein which carries ... It helps our muscles store and use oxygen. Iron is also part of many other proteins and ...

  18. Broad Line Radio Galaxies Observed with Fermi-LAT: The Origin of the GeV Gamma-Ray Emission

    Energy Technology Data Exchange (ETDEWEB)

    Kataoka, J.; /Waseda U., RISE; Stawarz, L.; /JAXA, Sagamihara /Jagiellonian U., Astron. Observ.; Takahashi, Y.; /Waseda U., RISE; Cheung, C.C.; /Natl. Acad. Sci. /Naval Research Lab, Wash., D.C.; Hayashida, M.; /SLAC /Stanford U., HEPL /KIPAC, Menlo Park; Grandi, P.; /Bologna Observ.; Burnett, T.H.; /Washington U., Seattle; Celotti, A.; /SISSA, Trieste; Fegan, S.J.; Fortin, P.; /Ecole Polytechnique; Maeda, K.; Nakamori, T.; /Waseda U., RISE; Taylor, G.B.; /New Mexico U.; Tosti, G.; /INFN, Perugia /Perugia U.; Digel, S.W.; /SLAC /Stanford U., HEPL /KIPAC, Menlo Park; McConville, W.; /NASA, Goddard /Maryland U.; Finke, J.; /Naval Research Lab, Wash., D.C.; D' Ammando, F.; /IASF, Palermo /INAF, Rome

    2012-06-07

    We report on a detailed investigation of the {gamma}-ray emission from 18 broad line radio galaxies (BLRGs) based on two years of Fermi Large Area Telescope (LAT) data. We confirm the previously reported detections of 3C 120 and 3C 111 in the GeV photon energy range; a detailed look at the temporal characteristics of the observed {gamma}-ray emission reveals in addition possible flux variability in both sources. No statistically significant {gamma}-ray detection of the other BLRGs was however found in the considered dataset. Though the sample size studied is small, what appears to differentiate 3C 111 and 3C 120 from the BLRGs not yet detected in {gamma}-rays is the particularly strong nuclear radio flux. This finding, together with the indications of the {gamma}-ray flux variability and a number of other arguments presented, indicate that the GeV emission of BLRGs is most likely dominated by the beamed radiation of relativistic jets observed at intermediate viewing angles. In this paper we also analyzed a comparison sample of high accretion-rate Seyfert 1 galaxies, which can be considered radio-quiet counterparts of BLRGs, and found none were detected in {gamma}-rays. A simple phenomenological hybrid model applied for the broad-band emission of the discussed radio-loud and radio-quiet type 1 active galaxies suggests that the relative contribution of the nuclear jets to the accreting matter is {ge} 1% on average for BLRGs, while {le} 0.1% for Seyfert 1 galaxies.

  19. Marine Mammal Train Oil Production Methods: Experimental Reconstructions of Norwegian Iron Age Slab-Lined Pits

    Science.gov (United States)

    Nilsen, Gørill

    2016-08-01

    Seal hunting and whaling have played an important part of people's livelihoods throughout prehistory as evidenced by rock carvings, remains of bones, artifacts from aquatic animals and hunting tools. This paper focuses on one of the more elusive resources relating to such activities: marine mammal blubber. Although marine blubber easily decomposes, the organic material has been documented from the Mesolithic Period onwards. Of particular interest in this article are the many structures in Northern Norway from the Iron Age and in Finland on Kökar, Åland, from both the Bronze and Early Iron Ages in which these periods exhibited traits interpreted as being related to oil rendering from marine mammal blubber. The article discusses methods used in this oil production activity based on historical sources, archaeological investigations and experimental reconstruction of Iron Age slab-lined pits from Northern Norway.

  20. Measurements of a crenelated iron pole tip for the VLHC transmission line magnet

    CERN Document Server

    Di Marco, J; Kashikhin, V V; Makarov, A A; Schlabach, P; MacKay, W W

    1999-01-01

    The Very Large Hadron Collider (VLHC) is under conceptual design in Fermilab. One option under development is a 2-Tesla warm iron 2-in-1 single turn superferric magnet built around an 80 kA superconducting transmission line. A normal-conducting test stand was built to optimize the iron lamination shape for this magnet. It uses a water- cooled copper winding to provide the 100 kA-turns needed to generate 2 Tesla fields in both 20 mm air gaps of the magnet. A magnetic measurement facility has been set up for magnetic field mapping, which includes a flat measurement coil, precision stage for coil motion and integrator. Results from a first test of the "crenelation" technique to mitigate the saturation sextupole in iron magnets are described and future plans are discussed. (5 refs).

  1. Marine Mammal Train Oil Production Methods: Experimental Reconstructions of Norwegian Iron Age Slab-Lined Pits

    Science.gov (United States)

    Nilsen, Gørill

    2016-02-01

    Seal hunting and whaling have played an important part of people's livelihoods throughout prehistory as evidenced by rock carvings, remains of bones, artifacts from aquatic animals and hunting tools. This paper focuses on one of the more elusive resources relating to such activities: marine mammal blubber. Although marine blubber easily decomposes, the organic material has been documented from the Mesolithic Period onwards. Of particular interest in this article are the many structures in Northern Norway from the Iron Age and in Finland on Kökar, Åland, from both the Bronze and Early Iron Ages in which these periods exhibited traits interpreted as being related to oil rendering from marine mammal blubber. The article discusses methods used in this oil production activity based on historical sources, archaeological investigations and experimental reconstruction of Iron Age slab-lined pits from Northern Norway.

  2. Boltzmann statistical consideration on the excitation mechanism of iron atomic lines emitted from glow discharge plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Lei; Kashiwakura, Shunsuke; Wagatsuma, Kazuaki, E-mail: wagatuma@imr.tohoku.ac.jp

    2011-11-15

    A Boltzmann plot for many iron atomic lines having excitation energies of 3.3-6.9 eV was investigated in glow discharge plasmas when argon or neon was employed as the plasma gas. The plot did not show a linear relationship over a wide range of the excitation energy, but showed that the emission lines having higher excitation energies largely deviated from a normal Boltzmann distribution whereas those having low excitation energies (3.3-4.3 eV) well followed it. This result would be derived from an overpopulation among the corresponding energy levels. A probable reason for this is that excitations for the high-lying excited levels would be caused predominantly through a Penning-type collision with the metastable atom of argon or neon, followed by recombination with an electron and then stepwise de-excitations which can populate the excited energy levels just below the ionization limit of iron atom. The non-thermal excitation occurred more actively in the argon plasma rather than the neon plasma, because of a difference in the number density between the argon and the neon metastables. The Boltzmann plots yields important information on the reason why lots of Fe I lines assigned to high-lying excited levels can be emitted from glow discharge plasmas. - Highlights: Black-Right-Pointing-Pointer This paper shows the excitation mechanism of Fe I lines from a glow discharge plasma. Black-Right-Pointing-Pointer A Boltzmann distribution is studied among iron lines of various excitation levels. Black-Right-Pointing-Pointer We find an overpopulation of the high-lying energy levels from the normal distribution. Black-Right-Pointing-Pointer It is caused through Penning-type collision of iron atom with argon metastable atom.

  3. Boltzmann statistical consideration on the excitation mechanism of iron atomic lines emitted from glow discharge plasmas

    International Nuclear Information System (INIS)

    A Boltzmann plot for many iron atomic lines having excitation energies of 3.3–6.9 eV was investigated in glow discharge plasmas when argon or neon was employed as the plasma gas. The plot did not show a linear relationship over a wide range of the excitation energy, but showed that the emission lines having higher excitation energies largely deviated from a normal Boltzmann distribution whereas those having low excitation energies (3.3–4.3 eV) well followed it. This result would be derived from an overpopulation among the corresponding energy levels. A probable reason for this is that excitations for the high-lying excited levels would be caused predominantly through a Penning-type collision with the metastable atom of argon or neon, followed by recombination with an electron and then stepwise de-excitations which can populate the excited energy levels just below the ionization limit of iron atom. The non-thermal excitation occurred more actively in the argon plasma rather than the neon plasma, because of a difference in the number density between the argon and the neon metastables. The Boltzmann plots yields important information on the reason why lots of Fe I lines assigned to high-lying excited levels can be emitted from glow discharge plasmas. - Highlights: ► This paper shows the excitation mechanism of Fe I lines from a glow discharge plasma. ► A Boltzmann distribution is studied among iron lines of various excitation levels. ► We find an overpopulation of the high-lying energy levels from the normal distribution. ► It is caused through Penning-type collision of iron atom with argon metastable atom.

  4. Constraining sub-parsec binary supermassive black holes in quasars with multi-epoch spectroscopy. II. The population with kinematically offset broad Balmer emission lines

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xin [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States); Shen, Yue [Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Bian, Fuyan [Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611 (Australia); Loeb, Abraham [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Tremaine, Scott, E-mail: xinliu@astro.ucla.edu [Institute for Advanced Study, Princeton, NJ 08540 (United States)

    2014-07-10

    A small fraction of quasars have long been known to show bulk velocity offsets (of a few hundred to thousands of km s{sup –1}) in the broad Balmer lines with respect to the systemic redshift of the host galaxy. Models to explain these offsets usually invoke broad-line region gas kinematics/asymmetry around single black holes (BHs), orbital motion of massive (∼sub-parsec (sub-pc)) binary black holes (BBHs), or recoil BHs, but single-epoch spectra are unable to distinguish between these scenarios. The line-of-sight (LOS) radial velocity (RV) shifts from long-term spectroscopic monitoring can be used to test the BBH hypothesis. We have selected a sample of 399 quasars with kinematically offset broadlines from the Sloan Digital Sky Survey (SDSS) Seventh Data Release quasar catalog, and have conducted second-epoch optical spectroscopy for 50 of them. Combined with the existing SDSS spectra, the new observations enable us to constrain the LOS RV shifts of broadlines with a rest-frame baseline of a few years to nearly a decade. While previous work focused on objects with extreme velocity offset (>10{sup 3} km s{sup –1}), we explore the parameter space with smaller (a few hundred km s{sup –1}) yet significant offsets (99.7% confidence). Using cross-correlation analysis, we detect significant (99% confidence) radial accelerations in the broadlines in 24 of the 50 objects, of ∼10-200 km s{sup –1} yr{sup –1} with a median measurement uncertainty of ∼10 km s{sup –1} yr{sup –1}, implying a high fraction of variability of the broad-line velocity on multi-year timescales. We suggest that 9 of the 24 detections are sub-pc BBH candidates, which show consistent velocity shifts independently measured from a second broad line (either Hα or Mg II) without significant changes in the broad-line profiles. Combining the results on the general quasar population studied in Paper I, we find a tentative anti-correlation between the velocity offset in the

  5. STAR FORMATION IN SELF-GRAVITATING DISKS IN ACTIVE GALACTIC NUCLEI. II. EPISODIC FORMATION OF BROAD-LINE REGIONS

    Energy Technology Data Exchange (ETDEWEB)

    WangJianmin; Du Pu; Ge Junqiang; Hu Chen [Key Laboratory for Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, 19B Yuquan Road, Beijing 100049 (China); Baldwin, Jack A. [Physics and Astronomy Department, 3270 Biomedical Physical Sciences Building, Michigan State University, East Lansing, MI 48824 (United States); Ferland, Gary J., E-mail: wangjm@mail.ihep.ac.cn [Department of Physics and Astronomy, 177 Chemistry/Physics Building, University of Kentucky, Lexington, KY 40506 (United States)

    2012-02-20

    This is the second in a series of papers discussing the process and effects of star formation in the self-gravitating disk around the supermassive black holes in active galactic nuclei (AGNs). We have previously suggested that warm skins are formed above the star-forming (SF) disk through the diffusion of warm gas driven by supernova explosions. Here we study the evolution of the warm skins when they are exposed to the powerful radiation from the inner part of the accretion disk. The skins initially are heated to the Compton temperature, forming a Compton atmosphere (CAS) whose subsequent evolution is divided into four phases. Phase I is the duration of pure accumulation supplied by the SF disk. During phase II clouds begin to form due to line cooling and sink to the SF disk. Phase III is a period of preventing clouds from sinking to the SF disk through dynamic interaction between clouds and the CAS because of the CAS overdensity driven by continuous injection of warm gas from the SF disk. Finally, phase IV is an inevitable collapse of the entire CAS through line cooling. This CAS evolution drives the episodic appearance of broad-line regions (BLRs). We follow the formation of cold clouds through the thermal instability of the CAS during phases II and III, using linear analysis. Since the clouds are produced inside the CAS, the initial spatial distribution of newly formed clouds and angular momentum naturally follow the CAS dynamics, producing a flattened disk of clouds. The number of clouds in phases II and III can be estimated, as well as the filling factor of clouds in the BLR. Since the cooling function depends on the metallicity, the metallicity gradients that originate in the SF disk give rise to different properties of clouds in different radial regions. We find from the instability analysis that clouds have column density N{sub H} {approx}< 10{sup 22} cm{sup -2} in the metal-rich regions whereas they have N{sub H} {approx}> 10{sup 22} cm{sup -2} in the

  6. Nustar Reveals an Intrinsically X-ray Weak Broad Absorption Line Quasar in the Ultraluminous Infrared Galaxy Markarian 231

    Science.gov (United States)

    Teng, Stacy H.; Brandt. W. N.; Harrison, F. A.; Luo, B.; Alexander, D. M.; Bauer, F. E.; Boggs, S. E.; Christensen, F. E.; Comastri, A.; Craig, W. W.; Fabian, A. C.; Farrah, D.; Fiore, F.; Gandhi, P.; Grefenstette, B. W.; Hailey, C. J.; Hickox, R. C.; Madsen, K. K.; Ptak, A. F.; Rigby, Jane Rebecca; Risaliti, G.; Saz, C.; Stern, D.; Veilleux, S.; Walton, D. J.; Wik, D. R.; Zhang, W. W.

    2014-01-01

    We present high-energy (3-30 keV) NuSTAR observations of the nearest quasar, the ultraluminous infrared galaxy (ULIRG) Markarian 231 (Mrk 231), supplemented with new and simultaneous low-energy (0.5-8 keV) data from Chandra. The source was detected, though at much fainter levels than previously reported, likely due to contamination in the large apertures of previous non-focusing hard X-ray telescopes. The full band (0.5-30 keV) X-ray spectrum suggests the active galactic nucleus (AGN) in Mrk 231 is absorbed by a patchy and Compton-thin N(sub H) approx. 1.2(sup +0.3) sub-0.3) x 10(exp 23) / sq cm) column. The intrinsic X-ray luminosity L(sub 0.5-30 Kev) approx. 1.0 x 10(exp 43) erg /s) is extremely weak relative to the bolometric luminosity where the 2-10 keV to bolometric luminosity ratio is approx. 0.03% compared to the typical values of 2-15%. Additionally, Mrk 231 has a low X-ray-to-optical power law slope alpha(sub 0X) approx. -1.7. It is a local example of a low-ionization broad absorption line (LoBAL) quasar that is intrinsically X-ray weak. The weak ionizing continuum may explain the lack of mid-infrared [O IV], [Ne V], and [Ne VI] fine-structure emission lines which are present in sources with otherwise similar AGN properties. We argue that the intrinsic X-ray weakness may be a result of the super-Eddington accretion occurring in the nucleus of this ULIRG, and may also be naturally related to the powerful wind event seen in Mrk 231, a merger remnant escaping from its dusty cocoon.

  7. A study for testing the Kerr metric with AGN iron line eclipses

    CERN Document Server

    Cardenas-Avendano, Alejandro; Bambi, Cosimo

    2016-01-01

    Recently, two of us have studied iron line reverberation mapping to test black hole candidates, showing that the time information in reverberation mapping can better constrain the Kerr metric than the time-integrated approach. Motivated by this finding, here we explore the constraining power of another time-dependent measurement: an AGN iron line eclipse. An obscuring cloud passes between the AGN and the distant observer, covering different parts of the accretion disk at different times. Similar to the reverberation measurement, an eclipse might help to better identify the relativistic effects affecting the X-ray photons. However, this is not what we find. We explain our results pointing out an important difference between reverberation and eclipse measurements.

  8. Testing the Kerr black hole hypothesis: Comparison between the gravitational wave and the iron line approaches

    Science.gov (United States)

    Cárdenas-Avendaño, Alejandro; Jiang, Jiachen; Bambi, Cosimo

    2016-09-01

    The recent announcement of the detection of gravitational waves by the LIGO/Virgo Collaboration has opened a new window to test the nature of astrophysical black holes. Konoplya & Zhidenko have shown how the LIGO data of GW 150914 can constrain possible deviations from the Kerr metric. In this letter, we compare their constraints with those that can be obtained from accreting black holes by fitting their X-ray reflection spectrum, the so-called iron line method. We simulate observations with eXTP, a next generation X-ray mission, finding constraints much stronger than those obtained by Konoplya & Zhidenko. Our results can at least show that, contrary to what is quite commonly believed, it is not obvious that gravitational waves are the most powerful approach to test strong gravity. In the presence of high quality data and with the systematics under control, the iron line method may provide competitive constraints.

  9. Testing the Kerr black hole hypothesis: comparison between the gravitational wave and the iron line approaches

    CERN Document Server

    Cardenas-Avendano, Alejandro; Bambi, Cosimo

    2016-01-01

    The recent announcement of the detection of gravitational waves by the LIGO/Virgo collaboration has opened a new window to test the nature of astrophysical black holes. Konoplya & Zhidenko have shown how the LIGO data of GW 150914 can constrain possible deviations from the Kerr metric. In this letter, we compare their constraints with those that can be obtained from accreting black holes by fitting their reflected X-ray spectrum, the so-called iron line method. We simulate observations with eXTP, a next generation X-ray mission, finding constraints much stronger than those obtained by Konoplya & Zhidenko. Our results can at least show that, contrary to what is quite commonly believed, it is not obvious that gravitational waves are the most powerful approach to test strong gravity. In the presence of high quality data and with the systematics under control, the iron line method may provide competitive constraints.

  10. Testing the Kerr black hole hypothesis: Comparison between the gravitational wave and the iron line approaches

    Directory of Open Access Journals (Sweden)

    Alejandro Cárdenas-Avendaño

    2016-09-01

    Full Text Available The recent announcement of the detection of gravitational waves by the LIGO/Virgo Collaboration has opened a new window to test the nature of astrophysical black holes. Konoplya & Zhidenko have shown how the LIGO data of GW 150914 can constrain possible deviations from the Kerr metric. In this letter, we compare their constraints with those that can be obtained from accreting black holes by fitting their X-ray reflection spectrum, the so-called iron line method. We simulate observations with eXTP, a next generation X-ray mission, finding constraints much stronger than those obtained by Konoplya & Zhidenko. Our results can at least show that, contrary to what is quite commonly believed, it is not obvious that gravitational waves are the most powerful approach to test strong gravity. In the presence of high quality data and with the systematics under control, the iron line method may provide competitive constraints.

  11. Unveiling the Intrinsic X-ray Properties of Broad Absorption Line Quasars with a Relatively Unbiased Sample

    CERN Document Server

    Morabito, Leah K; Leighly, Karen M; Sivakoff, Gregory R; Shankar, Francesco

    2013-01-01

    There is growing evidence of a higher intrinsic fraction of broad absorption line quasars (BALQSOs) than that obtained in optical surveys, on which most previous X-ray studies of BALQSOs have focused. Here we present Chandra observations of 18 BALQSOs at $z\\sim2$, selected from a near-infrared (2MASS) sample, where the BALQSO fraction is likely to be close to the intrinsic fraction. We measure photon indices using the stacked spectra of the optically-faint ($i-K_s\\geq 2.3$ mag) and optically-bright ($i-K_s < 2.3$ mag) samples to be $\\Gamma \\simeq 1.5$--2.1. We constrain their intrinsic column density by modelling the X-ray fractional hardness ratio, finding a mean column density of $3.5\\times10^{22}$ \\cmsq\\ assuming neutral absorption. We incorporate SDSS optical measurements (rest frame UV) to study the broadband spectral index between the X-ray and UV bands, and compare this to a large sample of normal quasars. We find that the optically-faint BALQSOs are X-ray weaker than the optically-bright ones, and ...

  12. Weak Hard X-ray Emission from Broad Absorption Line Quasars: Evidence for Intrinsic X-ray Weakness

    CERN Document Server

    Luo, B; Alexander, D M; Stern, D; Teng, S H; Arévalo, P; Bauer, F E; Boggs, S E; Christensen, F E; Comastri, A; Craig, W W; Farrah, D; Gandhi, P; Hailey, C J; Harrison, F A; Koss, M; Ogle, P; Puccetti, S; Saez, C; Scott, A E; Walton, D J; Zhang, W W

    2014-01-01

    We report NuSTAR observations of a sample of six X-ray weak broad absorption line (BAL) quasars. These targets, at z=0.148-1.223, are among the optically brightest and most luminous BAL quasars known at z330 times weaker than expected for typical quasars. Our results from a pilot NuSTAR study of two low-redshift BAL quasars, a Chandra stacking analysis of a sample of high-redshift BAL quasars, and a NuSTAR spectral analysis of the local BAL quasar Mrk 231 have already suggested the existence of intrinsically X-ray weak BAL quasars, i.e., quasars not emitting X-rays at the level expected from their optical/UV emission. The aim of the current program is to extend the search for such extraordinary objects. Three of the six new targets are weakly detected by NuSTAR with 33%) of intrinsically X-ray weak objects among the BAL quasars with significantly weak <10 keV emission. We suggest that intrinsically X-ray weak quasars might be preferentially observed as BAL quasars.

  13. Discovery of a variable broad absorption line in the BL Lac object PKS B0138-097

    Institute of Scientific and Technical Information of China (English)

    Shao-Hua Zhang; Hui-Yuan Wang; Hong-Yan Zhou; Ting-Gui Wang; Peng Jiang

    2011-01-01

    We report the discovery of a broad absorption line (BAL) of ~104 km s-1in width in the previously known BL Lac object PKS 0138-097,which we tentatively identified as an Mg Ⅱ BAL.This is the first detection of a BAL,which is sometimes seen in powerful quasars with high accretion rates,in a BL Lac object.The BAL was clearly detected in its spectra spanning two epochs at a high luminosity state taken in the Sloan Digital Sky Survey (SDSS),while it disappeared in three SDSS spectra taken at a low luminosity state.The BAL and its variability pattern were also found in its historical multi-epoch spectra in the literature,but have been overlooked previously.In its high resolution radio maps,PKS 0138-097 shows a core plus a onesided parsec-scale jet.The BAL variability can be interpreted as follows:The optical emission is dominated by the core in a high state and by the jet in a low state and the BAL material is located between the core and jet so that the BAL appears only when the core is shining.Our discovery suggests that outflows may also be produced in active galactic nuclei at a low accreting state.

  14. On the dynamics of clouds in the broad-line region of AGNs with an ADAF atmosphere

    CERN Document Server

    Khajenabi, Fazeleh

    2014-01-01

    We investigate orbital motion of spherical, pressure-confined clouds in the broad-line region (BLR) of active galactic nuclei (AGN). The combined influence of gravity of the central object and the non-isotropic radiation of the central source are taking into account. While most of the previous studies assume that the pressure of the intercloud gaseous component is proportional to a power-law function of the radial coordinate, we generalize it to a case where the external pressure depends on both the radial distance and the latitudinal angle. Our prescribed pressure profile determines the radius and the column density of BLR clouds as a function of their location. We also discuss about stability of the orbits and a condition for the existence of bound orbits is obtained. We found that BLR clouds tend to populate the equatorial regions more than other parts simply because of the stability considerations. Although this finding is obtained for a particular pressure profile, we think, this result is valid as long ...

  15. Weak Hard X-Ray Emission from Broad Absorption Line Quasars: Evidence for Intrinsic X-Ray Weakness

    DEFF Research Database (Denmark)

    Luo, B.; Brandt, W. N.; Alexander, D. M.;

    2014-01-01

    We report NuSTAR observations of a sample of six X-ray weak broad absorption line (BAL) quasars. These targets, at z = 0.148-1.223, are among the optically brightest and most luminous BAL quasars known at z 330 times weaker than...... are not detected. The hard X-ray (8-24 keV) weakness observed by NuSTAR requires Compton-thick absorption if these objects have nominal underlying X-ray emission. However, a soft stacked effective photon index (Γeff ≈ 1.8) for this sample disfavors Compton-thick absorption in general. The uniform hard X...... expected for typical quasars. Our results from a pilot NuSTAR study of two low-redshift BAL quasars, a Chandra stacking analysis of a sample of high-redshift BAL quasars, and a NuSTAR spectral analysis of the local BAL quasar Mrk 231 have already suggested the existence of intrinsically X-ray weak BAL...

  16. Diffusion of water at low saturation levels into sandstone rock plugs measured by broad line magnetic resonance profiling

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, P.J.; Roberts, S.P. [Univ. of Surrey, Guildford (United Kingdom). Dept. of Physics; Pritchard, T. [British Gas PLC, Loughborough (United Kingdom)

    1996-02-10

    The ability to visualize water and oil in rock plugs is of substantial importance in the modeling of diffusion processes within rock and the subsequent development of enhanced oil recovery techniques from reservoir fields. Broad line magnetic resonance imaging has been used to profile water ingress into a series of well-characterized sandstone rock plugs at saturation levels below the vapor percolation threshold. The diffusion process has been found to be strongly anomalous. Rather, it is in quantitative agreement with a model based on parallel transport of water in the vapor phase and adsorbed on the pore surfaces with the vapor and pore surface water maintained in dynamic local equilibrium. Among other parameters, the analysis has yielded estimates of the surface water diffusion coefficients (mean 5 {times} 10{sup {minus}6} cm{sup 2}/s) and of the critical depths of surface water below which the vapor pressure is substantially reduced by strong adsorption (mean 30 molecular layers). A temperature-dependent study of one plug has shown that the pore surface water diffusion is thermally activated and is governed by an Arrhenius rate law with an activation energy of 49 kJ/mol.

  17. Multifrequency VLBI Observations of the Broad Absorption Line Quasar J1020+4320: Recently Restarted Jet Activity?

    Science.gov (United States)

    Doi, Akihiro; Murata, Yasuhiro; Mochizuki, Nanako; Takeuchi, Hiroshi; Asada, Keiichi; Hayashi, Takayuki J.; Nagai, Hiroshi; Shibata, Katsunori M.; Oyama, Tomoaki; Jike, Takaaki; Fujisawa, Kenta; Sugiyama, Koichiro; Ogawa, Hideo; Kimura, Kimihiro; Honma, Mareki; Kobayashi, Hideyuki; Koyama, Shoko

    2013-06-01

    This paper reports on very-long-baseline interferometry observations of the radio-loud broad absorption line (BAL) quasar J1020+4320 at 1.7, 2.3, 6.7, and 8.4 GHz using the Japanese VLBI network (JVN) and European VLBI network (EVN). The radio morphology is compact with a size of ˜10 pc. The convex radio spectrum has been stable over the last decade; an observed peak frequency of 3.2 GHz is equivalent to 9.5 GHz in the rest frame, suggesting an age on the order of ˜100 years as a radio source, according to an observed correlation between the linear size and the peak frequency of compact steep spectrum (CSS) and giga-hertz peaked spectrum (GPS) radio sources. A low-frequency radio excess suggests a relic of past jet activity. J1020+4320 may be one of the quasars with recurrent and short-lived jet activity during a BAL-outflowing phase.

  18. Multifrequency VLBI Observations of the Broad Absorption Line Quasar J1020+4320: Recently Restarted Jet Activity?

    CERN Document Server

    Doi, Akihiro; Mochizuki, Nanako; Takeuchi, Hiroshi; Asada, Keiichi; Hayashi, Takayuki J; Nagai, Hiroshi; Shibata, Katsunori M; Oyama, Tomoaki; Jike, Takaaki; Fujisawa, Kenta; Sugiyama, Koichiro; Ogawa, Hideo; Kimura, Kimihiro; Honma, Mareki; Kobayashi, Hideyuki; Koyama, Shoko

    2013-01-01

    This paper reports very-long-baseline interferometry observations of the radio-loud broad absorption line (BAL) quasar J1020+4320 at 1.7, 2.3, 6.7, and 8.4 GHz using the Japanese VLBI network (JVN) and European VLBI network (EVN). The radio morphology is compact with a size of ~10 pc. The convex radio spectrum is stable over the last decade; an observed peak frequency of 3.2 GHz is equivalent to 9.5 GHz in the rest frame, suggesting an age of the order of ~100 years as a radio source, according to an observed correlation between linear size and peak frequency of compact steep spectrum (CSS) and giga-hertz peaked spectrum (GPS) radio sources. A low-frequency radio excess suggests relic of past jet activity. J1020+4320 may be one of the quasars with recurrent and short-lived jet activity during a BAL-outflowing phase.

  19. Testing the Kerr Nature of Black Hole Candidates using Iron Line Spectra in the CPR Framework

    CERN Document Server

    Jiang, Jiachen; Steiner, James F

    2015-01-01

    The iron K$\\alpha$ line commonly observed in the X-ray spectrum of both stellar-mass and supermassive black hole candidates originates from X-ray fluorescence of the inner accretion disk. Accordingly, it can be used to map the spacetime geometry around these objects. In this paper, we extend previous work using the iron K$\\alpha$ line to test the Kerr black hole hypothesis. We adopt the Cardoso-Pani-Rico parametrization and we test the possibility of constraining possible deviations from the Kerr solution that can be obtained from observations across the range of black hole spins and inclination angles. We confirm previous claims that the iron K$\\alpha$ line is potentially a quite powerful probe for testing the Kerr metric given sufficiently high quality data and with systematics under control, especially in the case of fast-rotating black holes and high inclination angles since both conditions serve to maximize relativistic effects. We find that some geometric perturbations from Kerr geometry manifest more s...

  20. X-ray iron line variability constraints on the inner accretion disk

    CERN Document Server

    Reynolds, C S

    2000-01-01

    After reviewing the basic physics of X-ray reflection in AGN, we present three case studies which illustrate the current state of X-ray reflection studies. For the low-luminosity AGN NGC4258, we find that the iron line is much narrower than is typically found in higher luminosity AGN. We argue that this is evidence for either a truncated cold accretion disk (possibly due to a transition to an advection dominate accretion flow at r ~ 100GM/c^2) or a large r ~ 100GM/c^2 X-ray emitting corona surrounding the accretion disk. We also present results for the higher luminosity Seyfert nuclei in NGC5548 and MCG-6-30-15. In both of these sources, RXTE shows that the iron line equivalent width decreases with increasing luminosity. Furthermore, the iron line equivalent width is found to be anticorrelated with the relative strength of the reflection continuum, contrary to all simple reflection models. It is proposed that continuum-flux correlated changes in the ionization of the accretion disk surface can explain this sp...

  1. A COMPARATIVE STUDY OF OPTICAL/ULTRAVIOLET VARIABILITY OF NARROW-LINE SEYFERT 1 AND BROAD-LINE SEYFERT 1 ACTIVE GALACTIC NUCLEI

    International Nuclear Information System (INIS)

    The ensemble optical/ultraviolet (UV) variability of narrow-line Seyfert 1 (NLS1)-type active galactic nuclei (AGNs) is investigated, based on a sample selected from the Sloan Digital Sky Survey (SDSS) Stripe 82 region with multi-epoch photometric scanning data. As a comparison, a control sample of broad-line Seyfert 1 (BLS1)-type AGNs is also incorporated. To quantify properly the intrinsic variation amplitudes and their uncertainties, a novel method of parametric maximum likelihood is introduced that has, as we argued, certain virtues over previously used methods. The majority of NLS1-type AGNs exhibit significant variability on timescales from about 10 days to a few years with, however, smaller amplitudes on average compared to BLS1-type AGNs. About 20 NLS1-type AGNs that show relatively large variations are presented and may deserve future monitoring observations, for instance, reverberation mapping. The averaged structure functions of variability, constructed using the same maximum likelihood method, show remarkable similarity in shape for the two types of AGNs on timescales longer than about 10 days, which can be approximated by a power law or an exponential function. This, along with other similar properties, such as the wavelength-dependent variability, is indicative of a common dominant mechanism responsible for the long-term optical/UV variability of both NLS1- and BLS1-type AGNs. Toward the short timescales, however, there is tentative evidence that the structure function of NLS1-type AGNs continues to decline, whereas that of BLS1-type AGNs flattens with some residual variability on timescales of days. If this can be confirmed, it may suggest that an alternative mechanism, such as X-ray reprocessing, starts to dominate in BLS1-type AGNs, but not in NLS1-type AGNs, on such timescales.

  2. Constraining Sub-Parsec Binary Supermassive Black Holes in Quasars with Multi-Epoch Spectroscopy. II. The Population with Kinematically Offset Broad Balmer Emission Lines

    CERN Document Server

    Liu, Xin; Bian, Fuyan; Loeb, Abraham; Tremaine, Scott

    2013-01-01

    A small fraction of quasars have long been known to show bulk velocity offsets in the broad Balmer lines with respect to the systemic redshift of the host galaxy. Models to explain these offsets usually invoke broad line region gas kinematics/asymmetry around single black holes (BHs), orbital motion of massive (~sub-pc) binary black holes (BBHs), or recoil BHs, but single-epoch spectra are unable to distinguish between these scenarios. The line-of-sight (LOS) radial velocity (RV) shifts from long-term spectroscopic monitoring can be used to test the BBH hypothesis. We have selected a sample of 399 quasars with offset broad H-beta lines from the SDSS DR7 quasar catalog, and have conducted second-epoch optical spectroscopy for 50 of them. Combined with the existing SDSS spectra, the new observations enable us to constrain the LOS RV shifts of broad H-beta lines with a rest-frame baseline of a few years to nearly a decade. Using cross-correlation analysis, we detect significant (99% confidence) radial accelerati...

  3. Search for broad absorption lines in spectra of stars in the field of supernova remnant RX J0852.0-4622 (Vela Jr.)

    CERN Document Server

    Iyudin, A F; Chugai, N N; Greiner, J; Axelsson, M; Larsson, S; Ryabchikova, T A

    2010-01-01

    Supernova remnant (SNR) RX J0852.0-4622 is one of the youngest and is most likely the closest among known galactic supernova remnants (SNRs). It was detected in X-rays, the 44Ti gamma-line, and radio. We obtain and analyze medium-resolution spectra of 14 stars in the direction towards the SNR RX J0852.0-4622 in an attempt to detect broad absorption lines of unshocked ejecta against background stars. Spectral synthesis is performed for all the stars in the wavelength range of 3740-4020AA to extract the broad absorption lines of Ca II related to the SNR RX J0852.0-4622. We do not detect any broad absorption line and place a 3-sigma upper limit on the relative depths of <0.04 for the broad Ca II absorption produced by the SNR. We detect narrow low and high velocity absorption components of Ca II. High velocity |V(LSR)|=100-140 km/s components are attributed to radiative shocks in clouds engulfed by the old Vela SNR. The upper limit to the absorption line strength combined with the width and flux of the 44Ti g...

  4. Differential interferometry of QSO broad-line regions - I. Improving the reverberation mapping model fits and black hole mass estimates

    Science.gov (United States)

    Rakshit, Suvendu; Petrov, Romain G.; Meilland, Anthony; Hönig, Sebastian F.

    2015-03-01

    Reverberation mapping (RM) estimates the size and kinematics of broad-line regions (BLR) in quasars and type I AGNs. It yields size-luminosity relation to make QSOs standard cosmological candles, and mass-luminosity relation to study the evolution of black holes and galaxies. The accuracy of these relations is limited by the unknown geometry of the BLR clouds distribution and velocities. We analyse the independent BLR structure constraints given by super-resolving differential interferometry. We developed a three-dimensional BLR model to compute all differential interferometry and RM signals. We extrapolate realistic noises from our successful observations of the QSO 3C 273 with AMBER on the VLTI. These signals and noises quantify the differential interferometry capacity to discriminate and measure BLR parameters including angular size, thickness, spatial distribution of clouds, local-to-global and radial-to-rotation velocity ratios, and finally central black hole mass and BLR distance. A Markov Chain Monte Carlo model-fit, of data simulated for various VLTI instruments, gives mass accuracies between 0.06 and 0.13 dex, to be compared to 0.44 dex for RM mass-luminosity fits. We evaluate the number of QSOs accessible to observe with current (AMBER), upcoming (GRAVITY) and possible (OASIS with new generation fringe trackers) VLTI instruments. With available technology, the VLTI could resolve more than 60 BLRs, with a luminosity range larger than four decades, sufficient for a good calibration of RM mass-luminosity laws, from an analysis of the variation of BLR parameters with luminosity.

  5. Unveiling the intrinsic X-ray properties of broad absorption line quasars with a relatively unbiased sample

    Energy Technology Data Exchange (ETDEWEB)

    Morabito, Leah K.; Dai, Xinyu; Leighly, Karen M. [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, OK 73019 (United States); Sivakoff, Gregory R. [Department of Physics, University of Alberta, CCIS 4-183 Edmonton, AB T6G 2E1 (Canada); Shankar, Francesco [School of Physics and Astronomy, University of Southampton, Southampton SO17 IBJ (United Kingdom)

    2014-05-01

    There is growing evidence of a higher intrinsic fraction of broad absorption line quasars (BALQSOs) than that obtained in optical surveys, on which most previous X-ray studies of BALQSOs have focused. Here we present Chandra observations of 18 BALQSOs at z ∼ 2, selected from a near-infrared (Two Micron All Sky Survey) sample, where the BALQSO fraction is likely to be close to the intrinsic fraction. We measure photon indices using the stacked spectra of the optically faint (i – K{sub s} ≥ 2.3 mag) and optically bright (i – K{sub s} < 2.3 mag) samples to be Γ ≅ 1.5-2.1. We constrain their intrinsic column density by modeling the X-ray fractional hardness ratio, finding a mean column density of 3.5 × 10{sup 22} cm{sup –2} assuming neutral absorption. We incorporate Sloan Digital Sky Survey optical measurements (rest frame UV) to study the broadband spectral index between the X-ray and UV bands, and compare this to a large sample of normal quasars. We estimate that the optically faint BALQSOs are X-ray weaker than the optically bright ones, and the entire sample of BALQSOs are intrinsically X-ray weak when compared to normal active galactic nuclei (AGNs). Correcting for magnification of X-ray emission via gravitational lensing by the central black hole viewed at large inclination angles makes these BALQSOs even more intrinsically X-ray weak. Finally, we estimate AGN kinetic feedback efficiencies of a few percent for an X-ray wind of 0.3c in high-ionization BALQSOs. Combined with energy carried by low-ionization BALQSOs and UV winds, the total kinetic energy in BALQSOs can be sufficient to provide AGN kinetic feedback required to explain the co-evolution between black holes and host galaxies.

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

    Energy Technology Data Exchange (ETDEWEB)

    Pancoast, Anna; Brewer, Brendon J.; Treu, Tommaso; Bennert, Vardha N.; Sand, David J. [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Barth, Aaron J.; Cooper, Michael C. [Department of Physics and Astronomy, 4129 Frederick Reines Hall, University of California, Irvine, CA 92697-4575 (United States); Canalizo, Gabriela [Department of Physics and Astronomy, University of California, Riverside, CA 92521 (United States); Filippenko, Alexei V.; Li, Weidong; Cenko, S. Bradley; Clubb, Kelsey I. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Gates, Elinor L. [Lick Observatory, P.O. Box 85, Mount Hamilton, CA 95140 (United States); Greene, Jenny E. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Malkan, Matthew A. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095-1547 (United States); Stern, Daniel; Assef, Roberto J. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Boulevard, Pasadena, CA 91109 (United States); Woo, Jong-Hak [Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of); Bae, Hyun-Jin [Department of Astronomy and Center for Galaxy Evolution Research, Yonsei University, Seoul 120-749 (Korea, Republic of); Buehler, Tabitha, E-mail: pancoast@physics.ucsb.edu [Department of Physics and Astronomy, N283 ESC, Brigham Young University, Provo, UT 84602-4360 (United States); and others

    2012-07-20

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

  7. Chandra X-ray Observations of NGC 4258: Iron Absorption Lines from the Nucleus

    CERN Document Server

    Young, A J

    2004-01-01

    We report sub-arcsecond resolution X-ray imaging spectroscopy of the low luminosity active galactic nucleus of NGC 4258 and its immediate surroundings with the Chandra X-ray Observatory. NGC 4258 was observed four times, with the first two observations separated by one month, followed over a year later by two consecutive observations. The spectrum of the nucleus is well described by a heavily absorbed, hard X-ray power law of variable luminosity, plus a constant, thermal soft X-ray component. We do not detect an iron K alpha emission line with the upper limit to the equivalent width of a narrow, neutral iron line ranging between 94 and 887 eV (90% confidence) for the different observations. During the second observation on 2000-04-17, two narrow absorption features are seen with >99.5% confidence at ~6.4 keV and ~6.9 keV, which we identify as resonant absorption lines of Fe XVIII - Fe XIX K alpha and Fe XXVI K alpha, respectively. In addition, the 6.9 keV absorption line is probably variable on a timescale of...

  8. Iron

    DEFF Research Database (Denmark)

    Hansen, Jakob Bondo; Moen, I W; Mandrup-Poulsen, T

    2014-01-01

    The interest in the role of ferrous iron in diabetes pathophysiology has been revived by recent evidence of iron as an important determinant of pancreatic islet inflammation and as a biomarker of diabetes risk and mortality. The iron metabolism in the β-cell is complex. Excess free iron is toxic......, but at the same time, iron is required for normal β-cell function and thereby glucose homeostasis. In the pathogenesis of diabetes, iron generates reactive oxygen species (ROS) by participating in the Fenton chemistry, which can induce oxidative damage and apoptosis. The aim of this review is to present...... and discuss recent evidence, suggesting that iron is a key pathogenic factor in both type 1 and type 2 diabetes with a focus on inflammatory pathways. Pro-inflammatory cytokine-induced β-cell death is not fully understood, but may include iron-induced ROS formation resulting in dedifferentiation by activation...

  9. On-line iron ore slurry monitoring using laser induced plasma spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Barrette, L.; Turmel, S.; Boivin, J.-A. [Centre de recherche minerale (CRM), Quebec, PQ (Canada); Sabsabi, M. [Industrial Materials Inst. (IMI-NRC), Boucherville, PQ (Canada); Martinovic, T.I. [Iron Ore Company of Canada, Labrador City, NF (Canada); Ouellet, G. [Quebec Cartier Mining Company (QCMC), Port Cartier, PQ (Canada)

    1999-07-01

    In response to the need for a better control [Lb1] of the various additives used in the iron ore pellet making process, Laser-Induced Plasma Spectroscopy (LIPS) has been tested for the on-line monitoring of Si, AI, Ca, Mg, and C. This work shows that factors such as laser beam focusing, particle size, slurry density and mineralogical composition have to be taken into account to meet precision and accuracy requirements. An internal standardization (peak ratio) and an original multivariate calibration technique based on fuzzy logic concepts [Lb2] are [Lb3] used to minimize the effect of these factors. This paper describes the experimental set-up, the effect of influence factors and the results obtained both in the laboratory and in an iron ore plant. (author)

  10. Weak hard X-ray emission from two broad absorption line quasars observed with NuSTAR: Compton-thick absorption or intrinsic X-ray weakness?

    DEFF Research Database (Denmark)

    Luo, B.; Brandt, W. N.; Alexander, D. M.;

    2013-01-01

    We present Nuclear Spectroscopic Telescope Array (NuSTAR) hard X-ray observations of two X-ray weak broad absorption line (BAL) quasars, PG 1004+130 (radio loud) and PG 1700+518 (radio quiet). Many BAL quasars appear X-ray weak, probably due to absorption by the shielding gas between the nucleus...

  11. Radio observations of a sample of broad-lined type Ic supernovae discovered by PTF/iPTF: A search for relativistic explosions

    CERN Document Server

    Corsi, A; Kulkarni, S R; Frail, D A; Mazzali, P A; Cenko, S B; Kasliwal, M M; Cao, Y; Horesh, A; Palliyaguru, N; Perley, D A; Laher, R R; Taddia, F; Leloudas, G; Maguire, K; Nugent, P E; Sollerman, J; Sullivan, M

    2015-01-01

    Long duration gamma-ray bursts are thought to be a rare subclass of stripped-envelope core-collapse supernovae that launch collimated relativistic outflows (jets). All gamma-ray-burst-associated supernovae are spectroscopically of Type Ic with broad lines, but the fraction of broad-lined Type Ic supernovae harboring low-luminosity gamma-ray-bursts remains largely unconstrained. Some supernovae should be accompanied by off-axis gamma-ray burst jets that remain invisible initially, but then emerge as strong radio sources (as the jets decelerate). However, this critical prediction of the jet model for gamma-ray bursts has yet to be verified observationally. Here, we present K. G. Jansky Very Large Array radio observations of 15 broad-lined supernovae of Type Ic discovered by the Palomar Transient Factory in an untargeted manner. Most of the supernovae in our sample exclude radio emission observationally similar to that of the radio-loud, relativistic SN 1998bw. We thus constrain the fraction of 1998bw-like broad...

  12. Iron line profiles and self-shadowing from relativistic thick accretion discs

    CERN Document Server

    Wu, Sheng-Miao

    2007-01-01

    We present Fe Kalpha line profiles from and images of relativistic discs with finite thickness around a rotating black hole using a novel code. The line is thought to be produced by iron fluorescence of a relatively cold X-ray illuminated material in the innermost parts of the accretion disc and provides an excellent diagnostic of accretion flows in the vicinity of black holes. Previous studies have concentrated on the case of a thin, Keplerian accretion disc. This disc must become thicker and sub-Keplerian with increasing accretion rates. These can affect the line profiles and in turn can influence the estimation of the accretion disc and black hole parameters from the observed line profiles. We here embark on, for the first time, a fully relativistic computation which offers key insights into the effects of geometrical thickness and the sub-Keplerian orbital velocity on the line profiles. We include all relativistic effects such as frame-dragging, Doppler boost, time dilation, gravitational redshift and lig...

  13. The effect of frame dragging on the iron K alpha line in X-ray binaries

    CERN Document Server

    Ingram, Adam

    2012-01-01

    The clear characteristic timescale picked out by the low frequency quasi-periodic oscillations (QPOs) seen in many black hole and neutron star binaries has the potential to provide a very powerful diagnostic of the inner regions of the accretion flow. However, this potential cannot be realised without a quantitative model for the QPO. We have recently shown that the same truncated disc/hot inner flow geometry which is used to interpret the spectral transitions can also directly produce the QPO from Lense-Thirring (vertical) precession of the hot inner flow. This correctly predicts both the frequency and spectrum of the QPO, and the tight correlation of these properties with the total spectrum of the source via a changing truncation radius between the disc and hot flow. This model predicts a unique iron line signature as a vertically tilted flow illuminates different azimuths of the disc as it precesses. The iron line arising from this rotating illumination is blue shifted when the flow irradiates the approach...

  14. Fluorescent iron lines as a probe of astrophysical black hole systems

    CERN Document Server

    Reynolds, C S; Reynolds, Christopher S.; Nowak, Michael A.

    2003-01-01

    (abridged) With most physicists and astrophysicists in agreement that black holes do indeed exist, the focus of astrophysical black hole research has shifted to the detailed properties of these systems. Nature has provided us with an extremely useful probe of the region very close to an accreting black hole - X-ray irradiation of relatively cold material in the vicinity of the black hole can imprint characteristic features into the X-ray spectra of black hole systems, most notably the Kalpha fluorescent line of iron. Detailed X-ray spectroscopy of these features can be used to study Doppler and gravitational redshifts, thereby providing key information on the location and kinematics of the cold material. This is a powerful tool that allows us to probe within a few gravitational radii, or less, of the event horizon. Here, we present a comprehensive review of relativistic iron line studies for both accreting stellar mass black holes (i.e., Galactic Black Hole Candidate systems; GBHCs), and accreting supermassiv...

  15. Comparative proteomic analysis of drug sodium iron chlorophyllin addition to Hep 3B cell line.

    Science.gov (United States)

    Zhang, Jun; Wang, Wenhai; Yang, Fengying; Zhou, Xinwen; Jin, Hong; Yang, Peng-yuan

    2012-09-21

    The human hepatoma 3B cell line was chosen as an experimental model for in vitro test of drug screening. The drugs included chlorophyllin and its derivatives such as fluo-chlorophyllin, sodium copper chlorophyllin, and sodium iron chlorophyllin. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) method was used in this study to obtain the primary screening results. The results showed that sodium iron chlorophyllin had the best LC(50) value. Proteomic analysis was then performed for further investigation of the effect of sodium iron chlorophyllin addition to the Hep 3B cell line. The proteins identified from a total protein extract of Hep 3B before and after the drug addition were compared by two-dimensional-gel-electrophoresis. Then 32 three-fold differentially expressed proteins were successfully identified by MALDI-TOF-TOF-MS. There are 29 unique proteins among those identified proteins. These proteins include proliferating cell nuclear antigen (PCNA), T-complex protein, heterogeneous nuclear protein, nucleophosmin, heat shock protein A5 (HspA5) and peroxiredoxin. HspA5 is one of the proteins which are involved in protecting cancer cells against stress-induced apoptosis in cultured cells, protecting them against apoptosis through various mechanisms. Peroxiredoxin has anti-oxidant function and is related to cell proliferation, and signal transduction. It can protect the oxidation of other proteins. Peroxiredoxin has a close relationship with cancer and can eventually become a disease biomarker. This might help to develop a novel treatment method for carcinoma cancer.

  16. Indirect X-Ray Line-Formation Processes in Iron L-Shell Ions

    Science.gov (United States)

    Gu, M. F.

    2003-01-01

    We present a systematic study of the role of indirect processes in the soft X-ray line formation of iron L-shell ions, using a newly developed, relativistic, multiconfigurational atomic package. These indirect processes involve the neighboring charge states of the target ion, namely, radiative recombination, dielectronic recombination, and resonance excitation. For Fe XVII, the inner-shell collisional ionization (CI) is also relevant. Lines originating from 3s and 3p upper levels of Fe XVII-XX are found to be significantly affected by these processes, with some lines being enhanced by nearly a factor of 2 at the temperature of maximum fractional abundance in CI equilibrium. Such enhancement, although not enough to completely explain the observed line ratios from various astrophysical sources, is a vast improvement over the previous models neglecting these processes. Rate coefficients for individual processes are tabulated, which can be conveniently included in spectral models to correctly account for these effects. As a by-product of this investigation, the total recombination and ionization rates of all Fe L-shell ions are tabulated as a function of temperature.

  17. IRAS 13197-1627 has them all: Compton-thin absorption, photo-ionized gas, thermal plasmas, and a broad Fe line

    OpenAIRE

    G. Miniutti(Centro de Astrobiologia); Ponti, G; Dadina, M.; Cappi, M.; Malaguti, G.

    2006-01-01

    We report results from the XMM-Newton observation of IRAS 13197-1627, a luminous IR galaxy with a Seyfert 1.8 nucleus. The hard X-ray spectrum is steep and is absorbed by Compton-thin neutral gas. We detect an Fe emission line at 6.4 keV, consistent with transmission through the absorber. The most striking result of our spectral analysis is the detection of a dominant X-ray reflection component and broad Fe line from the inner accretion disc. The reflection-dominated hard X-ray spectrum is co...

  18. VLT/ISAAC spectra of the Hβ region in intermediate-redshift quasars. III. Hβ broad-line profile analysis and inferences about BLR structure

    Science.gov (United States)

    Marziani, P.; Sulentic, J. W.; Stirpe, G. M.; Zamfir, S.; Calvani, M.

    2009-02-01

    Aims: We present new VLT ISAAC spectra for 30 quasars, which we combine with previous data to yield a sample of 53 intermediate-redshift (z ≈ 0.9-3.0) sources. The sample is used to explore properties of prominent lines in the hβ spectral region of these very luminous quasars. Methods: We compare this data with two large low-redshift (z < 0.8) samples in a search for trends over almost 6dex in source luminosity. Results: We find two major trends: (1) a systematic increase in minimum FWHM hβ with luminosity (discussed in a previous paper). This lower FWHM envelope is best fit by assuming that the narrowest sources radiate near the Eddington limit, show line emission from a virialized cloud distribution, and obey a well-defined broad line region size vs. luminosity relation. (2) A systematic decrease in equivalent width of [oiii]λλ4959, 5007 (from W ≈ 15 to ~1 Å) with increasing source bolometric luminosity (from log L_bol ≈ 43 to log L_bol ≈ 49). Other identified trends require differntiating between so-called Population A and Bsources. We generate median composite spectra in six luminosity bins to maximize S/N. Population A sources show reasonably symmetric Lorentzian hβ profiles at all luminosities, while Pop. B sources require two component fits involving an unshifted broad and a redshifted very broad component. Very broad hβ increases in strength with increasing log L_bol, while the broad component remains constant, resulting in an apparent “Baldwin effect” with equivalent width decreasing from W ~ 80 to ~20 Å over our sample luminosity range. The roughly constant equivalent width shown by the hβ very broad component implies production in optically-thick, photoionized gas. The onset of the redshifted very broad component appears to be a critical change that occurs near the Pop. A-B boundary at FWHM hβ ≈ 4000 km s-1, which we relate to a critical Eddington ratio (≈ 0.2±0.1). Based on observations made with ESO Telescopes at the Paranal

  19. Iron Fluorescent Line Emission from the mCvs and Hard X-ray Emitting Symbiotic Stars as a Source of the Iron Fluorescent Line Emission from the Galactic Ridge

    CERN Document Server

    Romanus, Eze; Ebisawa, Ken

    2015-01-01

    The Galactic Ridge X-ray Emission (GRXE) spectrum has strong iron emission lines at 6.4, 6.7, and 7.0~keV, each corresponding to the neutral (or low-ionized), He-like, and H-like iron ions. The 6.4~keV fluorescence line is due to irradiation of neutral (or low ionized) material (iron) by hard X-ray sources, indicating uniform presence of the cold matter in the Galactic plane. In order to resolve origin of the cold fluorescent matter, we examined the contribution of the 6.4~keV line emission from white dwarf surfaces in the hard X-ray emitting symbiotic stars (hSSs) and magnetic cataclysmic variables (mCVs) to the GRXE. In our spectral analysis of 4~hSSs and 19~mCVs observed with Suzaku, we were able to resolve the three iron emission lines. We found that the equivalent-widths (EWs) of the 6.4~keV lines of hSSs are systematically higher than those of mCVs, such that the average EWs of hSSs and mCVs are $179_{-11}^{+46}$~eV and $93_{-3}^{+20}$~eV, respectively. The EW of hSSs compares favorably with the typical...

  20. Relativistic iron lines in accretion disks: the contribution of higher order images in the strong deflection limit

    CERN Document Server

    Aldi, G F

    2016-01-01

    The shape of relativistic iron lines observed in spectra of candidate black holes carry the signatures of the strong gravitational fields in which the accretion disks lie. These lines result from the sum of the contributions of all images of the disk created by gravitational lensing, with the direct and first-order images largely dominating the overall shapes. Higher order images created by photons tightly winding around the black holes are often neglected in the modeling of these lines, since they require a substantially higher computational effort. With the help of the strong deflection limit, we present the most accurate semi-analytical calculation of these higher order contributions to the iron lines for Schwarzschild black holes. We show that two regimes exist depending on the inclination of the disk with respect to the line of sight. Many useful analytical formulae can be also derived in this framework.

  1. Self-shadowing effects of slim accretion disks in active galactic nuclei: the diverse appearance of the broad-line region

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jian-Min; Qiu, Jie; Du, Pu [Key Laboratory for Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, 19B Yuquan Road, Beijing 100049 (China); Ho, Luis C. [Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100875 (China)

    2014-12-10

    Supermassive black holes in active galactic nuclei (AGNs) undergo a wide range of accretion rates, which lead to diversity of appearance. We consider the effects of anisotropic radiation from accretion disks on the broad-line region (BLR) from the Shakura-Sunyaev regime to slim disks with super-Eddington accretion rates. The geometrically thick funnel of the inner region of slim disks produces strong self-shadowing effects that lead to very strong anisotropy of the radiation field. We demonstrate that the degree of anisotropy of the radiation fields grows with increasing accretion rate. As a result of this anisotropy, BLR clouds receive different spectral energy distributions depending on their location relative to the disk, resulting in the diverse observational appearance of the BLR. We show that the self-shadowing of the inner parts of the disk naturally produces two dynamically distinct regions of the BLR, depending on accretion rate. These two regions manifest themselves as kinematically distinct components of the broadline profile with different line widths and fluxes, which jointly account for the Lorentzian profile generally observed in narrow-line Seyfert 1 galaxies. In the time domain, these two components are expected to reverberate with different time lags with respect to the varying ionizing continuum, depending on the accretion rate and the viewing angle of the observer. The diverse appearance of the BLR due to the anisotropic ionizing energy source can be tested by reverberation mapping of Hβ and other broad emission lines (e.g., Fe II), providing a new tool to diagnose the structure and dynamics of the BLR. Other observational consequences of our model are also explored.

  2. Helium-Like Iron Line Temperature Diagnostics in Clusters of Galaxies

    Science.gov (United States)

    Swartz, Douglas A.; Sulkanen, Martin E.

    1993-01-01

    The emission complex around 6.7 keV, arising from He-like Fe lines and their dielectronic satellites, has been observed at low resolution in a number of clusters of galaxies. With sufficient spectral resolution as in, e.g., solar flare observations, the ratio, G = (x + y + z)/w, of the intercombination (x and y) and forbidden (z) to the resonance (w) lines arising from the n = 2 level of the He-like ion, is a sensitive temperature diagnostic. We examine this role for G in the context of spatially and spectrally resolved observations of clusters of galaxies. The temperature behavior of this ratio is strongly dependent on the spectral resolution. We introduce an alternative definition for G that includes the contribution of satellite lines and improves the temperature fidelity of this diagnostic. We find that deprojection of the observed value of G along a line of sight through the cluster can yield accurate temperature profiles for temperatures in the range 10(exp 7)-10(exp 8) K that do not suffer from the cluster model uncertainties inherent in deconvolution of broad-band X-ray surface brightness profiles.

  3. Melon RNA interference (RNAi) lines silenced for Cm-eIF4E show broad virus resistance.

    Science.gov (United States)

    Rodríguez-Hernández, Ana M; Gosalvez, Blanca; Sempere, Raquel N; Burgos, Lorenzo; Aranda, Miguel A; Truniger, Verónica

    2012-09-01

    Efficient and sustainable control of plant viruses may be achieved using genetically resistant crop varieties, although resistance genes are not always available for each pathogen; in this regard, the identification of new genes that are able to confer broad-spectrum and durable resistance is highly desirable. Recently, the cloning and characterization of recessive resistance genes from different plant species has pointed towards eukaryotic translation initiation factors (eIF) of the 4E family as factors required for the multiplication of many different viruses. Thus, we hypothesized that eIF4E may control the susceptibility of melon (Cucumis melo L.) to a broad range of viruses. To test this hypothesis, Cm-eIF4E knockdown melon plants were generated by the transformation of explants with a construct that was designed to induce the silencing of this gene, and the plants from T2 generations were genetically and phenotypically characterized. In transformed plants, Cm-eIF4E was specifically silenced, as identified by the decreased accumulation of Cm-eIF4E mRNA and the appearance of small interfering RNAs derived from the transgene, whereas the Cm-eIF(iso)4E mRNA levels remained unaffected. We challenged these transgenic melon plants with eight agronomically important melon-infecting viruses, and identified that they were resistant to Cucumber vein yellowing virus (CVYV), Melon necrotic spot virus (MNSV), Moroccan watermelon mosaic virus (MWMV) and Zucchini yellow mosaic virus (ZYMV), indicating that Cm-eIF4E controls melon susceptibility to these four viruses. Therefore, Cm-eIF4E is an efficient target for the identification of new resistance alleles able to confer broad-spectrum virus resistance in melon.

  4. WISE J233237.05–505643.5: A double-peaked, broad-lined active galactic nucleus with a spiral-shaped radio morphology

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Chao-Wei [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Jarrett, T. H. [Astronomy Department, University of Cape Town, Private Bag X3, Rondebosch 7701 (South Africa); Stern, Daniel; Assef, Roberto J.; Eisenhardt, Peter R. M.; Wu, Jingwen [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, CA 91109 (United States); Emonts, Bjorn [Centro de Astrobiología (INTA-CSIC), Ctra de Torrejón a Ajalvir, km 4, E-28850 Torrejón de Ardoz, Madrid (Spain); Barrows, R. Scott [Arkansas Center for Space and Planetary Sciences, University of Arkansas, Fayetteville, AR 72701 (United States); Norris, Ray P. [Australia Telescope National Facility, CSIRO Astronomy and Space Science, P.O. Box 76, Epping NSW 1710 (Australia); Lonsdale, Carol [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Blain, Andrew W. [Department of Physics and Astronomy, University of Leicester, 1 University Road, Leicester LE1 7RH (United Kingdom); Benford, Dominic J. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Stalder, Brian; Stubbs, Christopher W. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); High, F. William [Kavli Institute for Cosmological Physics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Li, K. L.; Kong, Albert K. H., E-mail: Chao-Wei.Tsai@jpl.nasa.gov [Institute of Astronomy and Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan (China)

    2013-12-10

    We present radio continuum mapping, optical imaging, and spectroscopy of the newly discovered double-peaked, broad-lined active galactic nucleus (AGN) WISE J233237.05–505643.5 at redshift z = 0.3447. This source exhibits an FR-I and FR-II hybrid morphology, characterized by a bright core, jet, and Doppler-boosted lobe structures in Australian Telescope Compact Array continuum maps at 1.5, 5.6, and 9 GHz. Unlike most FR-II objects, W2332–5056 is hosted by a disk-like galaxy. The core has a projected 5'' linear radio feature that is perpendicular to the curved primary jet, hinting at unusual and complex activity within the inner 25 kpc. The multi-epoch, optical-near-IR photometric measurements indicate significant variability over a 3-20 yr baseline from the AGN component. Gemini South optical data show unusual double-peaked emission-line features: the centroids of the broad-lined components of Hα and Hβ are blueshifted with respect to the narrow lines and host galaxy by ∼3800 km s{sup –1}. We examine possible cases that involve single or double supermassive black holes in the system and discuss the required future investigations to disentangle the mysterious nature of this system.

  5. WISE J233237.05–505643.5: A double-peaked, broad-lined active galactic nucleus with a spiral-shaped radio morphology

    International Nuclear Information System (INIS)

    We present radio continuum mapping, optical imaging, and spectroscopy of the newly discovered double-peaked, broad-lined active galactic nucleus (AGN) WISE J233237.05–505643.5 at redshift z = 0.3447. This source exhibits an FR-I and FR-II hybrid morphology, characterized by a bright core, jet, and Doppler-boosted lobe structures in Australian Telescope Compact Array continuum maps at 1.5, 5.6, and 9 GHz. Unlike most FR-II objects, W2332–5056 is hosted by a disk-like galaxy. The core has a projected 5'' linear radio feature that is perpendicular to the curved primary jet, hinting at unusual and complex activity within the inner 25 kpc. The multi-epoch, optical-near-IR photometric measurements indicate significant variability over a 3-20 yr baseline from the AGN component. Gemini South optical data show unusual double-peaked emission-line features: the centroids of the broad-lined components of Hα and Hβ are blueshifted with respect to the narrow lines and host galaxy by ∼3800 km s–1. We examine possible cases that involve single or double supermassive black holes in the system and discuss the required future investigations to disentangle the mysterious nature of this system.

  6. WISE J233237.05-505643.5: A Double-Peaked Broad-Lined AGN with Spiral-Shaped Radio Morphology

    Science.gov (United States)

    Tsai, Chao Wei; Jarrett, Thomas H.; Stern, Daniel; Emonts, Bjorn; Barrows, R. Scott; Assef, Roberto J.; Norris, Ray P.; Eisenhardt, Peter R. M.; Lonsdale, Carol; Blain, Andrew W.; Benford, Dominic J.; Wu, Jingwen; Stalder, Brian; Stubbs, Christopher W.; High, F. William; Li, K. L.; Kong, Albert K. H.

    2013-01-01

    We present radio continuum mapping, optical imaging and spectroscopy of the newly discovered double-peaked broad-lined AGN WISE J233237.05-505643.5 at redshift z = 0.3447. This source exhibits an FR-I and FR-II hybrid-morphology, characterized by bright core, jet, and Doppler-boosted lobe structures in ATCA continuum maps at 1.5, 5.6, and 9 GHz. Unlike most FR-II objects, W2332-5056 is hosted by a disk-like galaxy. The core has a projected 5" linear radio feature that is perpendicular to the curved primary jet, hinting at unusual and complex activity within the inner 25 kpc. The multi-epoch optical-near-IR photometric measurements indicate significant variability over a 3-20 year baseline from the AGN component. Gemini-South optical data shows an unusual double-peaked emission-line features: the centroids of the broad-lined components of H-alpha and H-beta are blueshifted with respect to the narrow lines and host galaxy by approximately 3800 km/s. We examine possible cases which involve single or double supermassive black holes in the system, and discuss required future investigations to disentangle the mystery nature of this system.

  7. Testing the Kerr nature of black hole candidates using iron line reverberation mapping in the CPR framework

    CERN Document Server

    Jiang, Jiachen; Steiner, James F

    2016-01-01

    The iron K$\\alpha$ line commonly observed in the X-ray spectrum of black hole candidates is produced by X-ray fluorescence of the inner accretion disk. This line can potentially be quite a powerful tool to probe the spacetime geometry around these objects and test the Kerr black hole hypothesis. In a previous paper, we studied the ability to constrain possible deviations from the Kerr solution from the standard time-integrated iron line spectrum within the Cardoso-Pani-Rico framework. In the present work, we expand on that study and consider iron line reverberation mapping in the CPR framework. That is, we consider the time-evolution of the iron line profile in response to fluctuations in the X-ray primary source. Our simulations clearly show that the time information in reverberation mapping can better constrain the background metric than the time-integrated approach, and this is true, notably, for the deformation parameter $\\epsilon^r_3$, which is only weakly informed by a time-integrated observation.

  8. The broad emission-line region: the confluence of the outer accretion disc with the inner edge of the dusty torus

    Science.gov (United States)

    Goad, M. R.; Korista, K. T.; Ruff, A. J.

    2012-11-01

    We have investigated the observational characteristics of a class of broad emission line region (BLR) geometries that connect the outer accretion disc with the inner edge of the dusty toroidal obscuring region (TOR). We suggest that the BLR consists of photoionized gas of densities which allow for efficient cooling by ultraviolet (UV)/optical emission lines and of incident continuum fluxes which discourage the formation of grains, and that such gas occupies the range of distance and scale height between the continuum-emitting accretion disc and the dusty TOR. As a first approximation, we assume a population of clouds illuminated by ionizing photons from the central source, with the scale height of the illuminated clouds growing with increasing radial distance, forming an effective surface of a 'bowl'. Observer lines of sight which peer into the bowl lead to a Type 1 active galactic nuclei (AGN) spectrum. We assume that the gas dynamics are dominated by gravity, and we include in this model the effects of transverse Doppler shift (TDS), gravitational redshift (GR) and scale-height-dependent macroturbulence. Our simple model reproduces many of the commonly observed phenomena associated with the central regions of AGN, including (i) the shorter than expected continuum-dust delays (geometry), (ii) the absence of response in the core of the optical recombination lines on short time-scales (geometry/photoionization), (iii) an enhanced redwing response on short time-scales (GR and TDS), (iv) the observed differences between the delays for high- and low-ionization lines (photoionization), (v) identifying one of the possible primary contributors to the observed line widths for near face-on systems even for purely transverse motion (GR and TDS), (vi) a mechanism responsible for producing Lorentzian profiles (especially in the Balmer and Mg II emission lines) in low-inclination systems (turbulence), (vii) the absence of significant continuum-emission-line delays between the

  9. Analysis of high iron rice lines reveals new miRNAs that target iron transporters in roots

    Science.gov (United States)

    Paul, Soumitra; Gayen, Dipak; Datta, Swapan K.; Datta, Karabi

    2016-01-01

    The present study highlights the molecular regulation of iron transport in soyFER1-overexpressing transgenic rice. Accumulation of iron in three different seed developmental stages, milk, dough, and mature, has been examined. The transgenic seeds of the milk stage showed significant augmentation of iron and zinc levels compared with wild-type seeds, and similar results were observed throughout the dough and mature stages. To investigate the regulation of iron transport, the role of miRNAs was studied in roots of transgenic rice. Sequencing of small RNA libraries revealed 153 known and 41 novel miRNAs in roots. Among them, 59 known and 14 novel miRNAs were found to be significantly expressed. miR166, miR399, and miR408 were identified as playing a vital role in iron uptake in roots of transgenic plants . Most importantly, four putative novel miRNAs, namely miR11, miR26, miR30, and miR31, were found to be down-regulated in roots of transgenic plants. For all these four novel miRNAs, natural resistance-associated macrophage protein 4 (NRAMP4), encoding a metal transporter, was predicted as a target gene. It is hypothesized that the NRAMP4 transporter is activated in roots of transgenic plants due to the lower abundance of its corresponding putative novel miRNAs. The relative transcript level of the NRAMP4 transcript was increased from 0.107 in the wild type to 65.24 and 55.39 in transgenic plants, which demonstrates the elevated amount of iron transport in transgenic plants. In addition, up-regulation of OsYSL15, OsFRO2, and OsIRT1 in roots also facilitates iron loading in transgenic seeds. PMID:27729476

  10. MISALIGNMENT OF THE JET AND THE NORMAL TO THE DUSTY TORUS IN THE BROAD ABSORPTION LINE QSO FIRST J155633.8+351758

    International Nuclear Information System (INIS)

    We performed Very Long Baseline Array observations of the broad absorption line quasar FIRST J155633.8+351758, ''the first radio loud BALQSO''. Our observations at 15.3 GHz partially resolved a secondary component at position angle (P.A.) ≈35°. We combine this determination of the radio jet projection on the sky plane, with the constraint that the jet is viewed within 14.°3 of the line of sight (as implied by the high variability brightness temperature) and with the P.A. of the optical/UV continuum polarization in order to study the quasar geometry. Within the context of the standard model, the data indicates a ''dusty torus'' (scattering surface) with a symmetry axis tilted relative to the accretion disk normal and a polar broad absorption line outflow aligned with the accretion disk normal. We compare this geometry to that indicated by the higher resolution radio data, brightness temperature, and optical/UV continuum polarization P.A. of a similar high optical polarization BALQSO, Mrk 231. A qualitatively similar geometry is found in these two polar BALQSOs; the continuum polarization is determined primarily by the tilt of the dusty torus

  11. MISALIGNMENT OF THE JET AND THE NORMAL TO THE DUSTY TORUS IN THE BROAD ABSORPTION LINE QSO FIRST J155633.8+351758

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, Cormac [ICRAR-Curtin University, GPO Box U1987, Perth, Western Australia 6102 (Australia); Punsly, Brian [1415 Granvia Altamira, Palos Verdes Estates, CA 90274 (United States); O' Dea, Christopher P., E-mail: brian.punsly1@verizon.net, E-mail: brian.punsly@comdev-usa.com [Laboratory for Multiwavelength Astrophysics, School of Physics and Astronomy, Rochester Institute of Technology, 54 Lomb Memorial Drive, Rochester, NY 14623 (United States)

    2013-08-10

    We performed Very Long Baseline Array observations of the broad absorption line quasar FIRST J155633.8+351758, ''the first radio loud BALQSO''. Our observations at 15.3 GHz partially resolved a secondary component at position angle (P.A.) Almost-Equal-To 35 Degree-Sign . We combine this determination of the radio jet projection on the sky plane, with the constraint that the jet is viewed within 14. Degree-Sign 3 of the line of sight (as implied by the high variability brightness temperature) and with the P.A. of the optical/UV continuum polarization in order to study the quasar geometry. Within the context of the standard model, the data indicates a ''dusty torus'' (scattering surface) with a symmetry axis tilted relative to the accretion disk normal and a polar broad absorption line outflow aligned with the accretion disk normal. We compare this geometry to that indicated by the higher resolution radio data, brightness temperature, and optical/UV continuum polarization P.A. of a similar high optical polarization BALQSO, Mrk 231. A qualitatively similar geometry is found in these two polar BALQSOs; the continuum polarization is determined primarily by the tilt of the dusty torus.

  12. K-shell Emission of Neutral Iron Line from Sgr B2 Excited by Subrelativistic Protons

    CERN Document Server

    Dogiel, Vladimir; Koyama, Katsuji; Nobukawa, Masayoshi; Cheng, Kwong-Sang

    2011-01-01

    We investigated the emission of K$\\alpha$ iron line from the massive molecular clouds in the Galactic center (GC). We assume that at present the total flux of this emission consists of time variable component generated by primary X-ray photons ejected by Sagittarius A$^\\ast$ (Sgr A$^\\ast$) in the past and a relatively weak quasi-stationary component excited by impact of protons which were generated by star accretion onto the central black hole. The level of background emission was estimated from a rise of the 6.4 keV line intensity in the direction of several molecular clouds, that we interpreted as a stage when the X-ray front ejected by Sgr A$^\\ast$ entered into these clouds. The 6.4 keV emission before this intensity jump we interpreted as emission generated by subrelativistic cosmic rays there. The cross-section of K$\\alpha$ vacancies produced by protons differs from that of electrons or X-rays. Therefore, we expect that this processes can be distinguished from the analysis of the equivalent width of the ...

  13. Testing the no-hair theorem with the continuum-fitting and the iron line methods: a short review

    CERN Document Server

    Bambi, Cosimo; Steiner, James F

    2015-01-01

    The continuum-fitting and the iron line methods are leading techniques capable of probing the spacetime geometry around astrophysical black hole candidates and testing the no-hair theorem. In the present paper, we review the two approaches, from the astrophysical models and their assumptions, to the constraining power with present and future facilities.

  14. The broad emission-line region: the confluence of the outer accretion disc with the inner edge of the dusty torus

    CERN Document Server

    Goad, M R; Ruff, A J

    2012-01-01

    (Abridged) We investigate the observational characteristics of BLR geometries in which the BLR clouds bridge the gap, both in distance and scale height, between the outer accretion disc and the hot dust, forming an effective surface of a "bowl". The gas dynamics are dominated by gravity, and we include the effects of transverse Doppler shift, gravitational redshift and scale-height dependent macro-turbulence. Our simple model reproduces many of the phenomena observed in broad emission-line variability studies, including (i) the absence of response in the core of the optical recombination lines on short timescales, (ii) the enhanced red-wing response on short timescales, (iii) differences between the measured delays for the HILs and LILs, and (iv) identifies turbulence as a means of producing Lorentzian profiles (esp. for LILs) in low inclination systems, and for suppressing significant continuum--emission-line delays between the line wings and line core (esp. in LILs). A key motivation of this work was to rev...

  15. Iron

    Science.gov (United States)

    ... as recommended by an obstetrician or other health care provider. Infants and toddlers Iron deficiency anemia in infancy can lead to delayed psychological development, social withdrawal, and less ability to pay attention. By age 6 to 9 months, full-term infants could ...

  16. Theoretical investigation of the broad one-photon absorption line-shape of a flexible symmetric carbazole derivative.

    Science.gov (United States)

    Liu, Yanli; Cerezo, Javier; Santoro, Fabrizio; Rizzo, Antonio; Lin, Na; Zhao, Xian

    2016-08-17

    The one-photon absorption spectrum of a carbazole derivative has been studied by employing density functional response theory combined with a mixed quantum/classical (QC) approach to simulate the spectral shape. In a first step of our analysis we employed the vertical gradient (VG) vibronic model to investigate the role of Franck-Condon (FC) profiles of the first ten electronic excited states of the system, underlying most of the range of the experimental spectrum. We then focussed on the first six excited states covering the low-energy region of the spectrum, and investigated the effect of inter-state electronic couplings on the spectral shapes within Herzberg-Teller (HT) theory. Furthermore, in order to introduce the broadening effects due to the two inter-ring torsions, we employed a QC approach, adopting VG vibronic models for high-frequency modes and computing the contribution of the torsions to the spectrum from the distribution of the excitation energies along a two-dimensional relaxed potential energy. Finally, we estimated the solvent inhomogeneous broadening by computing the solvent reorganization energy using a polarizable continuum model. Our calculations allow us to obtain a non-phenomenological description of the low-energy part of the spectrum in semi-quantitative agreement with experiment and to dissect the relative importance of solvent, torsional flexibility, FC vibronic progressions, and inter-state couplings in determining its broad spectral shapes and the modulation of its intensity. Our analysis also clearly highlights that the investigated carbazole represents a big challenge for available methodologies due to the existence of many close-lying excited electronic states coupled by internal low-frequency and high-frequency motions and by solvent fluctuations. The study of their impact on the spectra at the HT level is only approximate and more refined treatments would require a fully quantum-dynamical calculation on the manifold of the coupled

  17. Discovery of a red and blue shifted iron disk line in the galactic jet source GRO J1655-40

    CERN Document Server

    Balucinska-Church, M

    1999-01-01

    We report the discovery of emission features in the X-ray spectrum of GRO J1655-40 obtained with RXTE during the observation of 1997, Feb 26. We have fitted the features firstly by two Gaussian lines which in four spectra analysed have average energies of 5.85 +/- 0.08 keV and 7.32 +/- 0.13 keV, strongly suggestive that these are the red and blue shifted wings of an iron disk line. These energies imply a velocity of ~0.33 c. The blue wing is less bright than in the calculated profiles of disk lines near a black hole subject to Doppler boosting, however known Fe absorption lines in GRO J1655-40 at energies between ~7 and 8 keV can reduce the apparent brightness of the blue wing. Secondly, we have fitted the spectra using the disk line model of Laor based on a full relativistic treatment plus an absorption line, and show that good fits are obtained. This gives a restframe energy of the disk line between 6.4 and 6.8 keV indicating that the line is iron K_alpha emission probably of significantly ionized material....

  18. NuSTAR Reveals the Comptonizing Corona of the Broad-Line Radio Galaxy 3C 382

    DEFF Research Database (Denmark)

    Ballantyne, D. R.; Bollenbacher, J. M.; Brenneman, L. W.;

    2014-01-01

    an excellent fit to both spectra and show that the coronal plasma cooled from $kT_e=330\\pm 30$ keV in the low flux data to $231^{+50}_{-88}$ keV in the high flux observation. This cooling behavior is typical of Comptonizing corona in Seyfert galaxies and is distinct from the variations observed in jet......-dominated sources. In the high flux observation, simultaneous Swift data are leveraged to obtain a broadband spectral energy distribution and indicates that the corona intercepts $\\sim 10$% of the optical and ultraviolet emitting accretion disk. 3C 382 exhibits very weak reflection features, with no detectable...... relativistic Fe K$\\alpha$ line, that may be best explained by an outflowing corona combined with an ionized inner accretion disk....

  19. Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. III - Further observations of NGC 5548 at optical wavelengths

    Science.gov (United States)

    Peterson, B. M.; Alloin, D.; Axon, D.; Balonek, T. J.; Bertram, R.; Boroson, T. A.; Christensen, J. A.; Clements, S. D.; Dietrich, M.; Elvis, M.

    1992-01-01

    The results of the second year of an intensive ground-based spectroscopic and photometric study of variability in the bright Seyfert 1 galaxy NGC 5548 are reported in order to study the relationship between continuum and emission-line variability. Relative to the first year of the monitoring program, the nucleus of NGC 5548 was considerably fainter and the continuum variations slower during the second year, but the continuum H-beta cross-correlation results for the two years are nearly identical. The variations in the broad H-beta emission-line lag behind those in the continuum by somewhat less than 20 days, as concluded from the first year's data.

  20. Detection of Broad H$\\alpha$ Emission Lines in the Late-time Spectra of a Hydrogen-poor Superluminous Supernova

    CERN Document Server

    Yan, Lin; Ofek, E; Gal-Yam, A; Mazzali, P; Perley, D; Vreeswijk, P; Leloudas, G; de Cia, A; Masci, F; Cenko, S B; Cao, Y; Kulkarni, S R; Nugent, P E; Rebbapragada, Umaa D; Woźniak, P R; Yaron, O

    2015-01-01

    iPTF13ehe is a hydrogen-poor superluminous supernova (SLSN) at z=0.3434, with properties similar to SN2007bi. It rises within (83-148)days (rest-frame) to reach a peak bolometric luminosity of 1.3x$10^{44}$erg/s, then decays very slowly at 0.015mag. per day. The measured ejecta velocity is 13000km/s. The inferred explosion characteristics, such as the ejecta mass (67-220$M_\\odot$), the total radiative and kinetic energy ($10^{51}$ & 2x$10^{53}$erg respectively), is typical of SLSN-R events. However, the late-time spectrum taken at +251days reveals a Balmer Halpha emission feature with broad and narrow components, which has never been detected before among other H-poor SLSNe. The broad component has a velocity width of ~4500km/s and has a ~300km/s blue-ward shift relative to the narrow component. We interpret this broad Halpha emission line as the interaction between the supernova ejecta and a H-rich circumstellar medium (CSM) shell, located at a distance of ~4x$10^{16}$cm from the explosion site. This eje...

  1. RHESSI Observations of the Solar Flare Iron-line Feature at 6.7 keV

    OpenAIRE

    Phillips, K. J. H.; Chifor, C.; Dennis, B. R.

    2006-01-01

    Analysis of RHESSI 3--10 keV spectra for 27 solar flares is reported. This energy range includes thermal free--free and free--bound continuum and two line features, at 6.7keV and 8keV, principally due to highly ionized iron (Fe). We used the continuum and the flux in the so-called Fe-line feature at 6.7keV to derive the electron temperature T_e, the emission measure, and the Fe-line equivalent width as functions of time in each flare. The Fe/H abundance ratio in each flare is derived from the...

  2. BLACK HOLE MASS AND EDDINGTON RATIO DISTRIBUTION FUNCTIONS OF X-RAY-SELECTED BROAD-LINE AGNs AT z {approx} 1.4 IN THE SUBARU XMM-NEWTON DEEP FIELD

    Energy Technology Data Exchange (ETDEWEB)

    Nobuta, K.; Akiyama, M. [Astronomical Institute, Tohoku University, 6-3 Aramaki, Aoba-ku, Sendai 980-8578 (Japan); Ueda, Y.; Hiroi, K.; Ohta, K.; Iwamuro, F.; Yabe, K.; Moritani, Y.; Sumiyoshi, M.; Maihara, T. [Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan); Watson, M. G. [XROA Group, Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH (United Kingdom); Silverman, J.; Tamura, N.; Kimura, M. [Kavli Institute for the Physics and Mathematics of the Universe, University of Tokyo, Kashiwa 277-8583 (Japan); Takato, N. [National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan); Dalton, G.; Lewis, I.; Bonfield, D.; Lee, H.; Curtis-Lake, E., E-mail: akiyama@astr.tohoku.ac.jp [Department of Astrophysics, University of Oxford, Keble Road, Oxford OX1 3RH (United Kingdom); and others

    2012-12-20

    In order to investigate the growth of supermassive black holes (SMBHs), we construct the black hole mass function (BHMF) and Eddington ratio distribution function (ERDF) of X-ray-selected broad-line active galactic nuclei (AGNs) at z {approx} 1.4 in the Subaru XMM-Newton Deep Survey (SXDS) field. A significant part of the accretion growth of SMBHs is thought to take place in this redshift range. Black hole masses of X-ray-selected broad-line AGNs are estimated using the width of the broad Mg II line and 3000 A monochromatic luminosity. We supplement the Mg II FWHM values with the H{alpha} FWHM obtained from our NIR spectroscopic survey. Using the black hole masses of broad-line AGNs at redshifts between 1.18 and 1.68, the binned broad-line AGN BHMFs and ERDFs are calculated using the V{sub max} method. To properly account for selection effects that impact the binned estimates, we derive the corrected broad-line AGN BHMFs and ERDFs by applying the maximum likelihood method, assuming that the ERDF is constant regardless of the black hole mass. We do not correct for the non-negligible uncertainties in virial BH mass estimates. If we compare the corrected broad-line AGN BHMF with that in the local universe, then the corrected BHMF at z = 1.4 has a higher number density above 10{sup 8} M{sub Sun} but a lower number density below that mass range. The evolution may be indicative of a downsizing trend of accretion activity among the SMBH population. The evolution of broad-line AGN ERDFs from z = 1.4 to 0 indicates that the fraction of broad-line AGNs with accretion rates close to the Eddington limit is higher at higher redshifts.

  3. The Sloan Digital Sky Survey Reverberation Mapping Project: First Broad-line Hbeta and MgII Lags at z>~0.3 from six-Month Spectroscopy

    CERN Document Server

    Shen, Yue; Grier, C J; Peterson, Bradley M; Denney, Kelly D; Trump, Jonathan R; Sun, Mouyuan; Brandt, W N; Kochanek, Christopher S; Dawson, Kyle S; Green, Paul J; Greene, Jenny E; Hall, Patrick B; Ho, Luis C; Jiang, Linhua; Kinemuchi, Karen; McGreer, Ian D; Petitjean, Patrick; Richards, Gordon T; Schneider, Donald P; Strauss, Michael A; Tao, Charling; Wood-Vasey, W M; Zu, Ying; Pan, Kaike; Bizyaev, Dmitry; Ge, Jian; Oravetz, Daniel; Simmons, Audrey

    2015-01-01

    Reverberation mapping (RM) measurements of broad-line region (BLR) lags in z>0.3 quasars are important for directly measuring black hole masses in these distant objects, but so far there have been limited attempts and success given the practical difficulties of RM in this regime. Here we report preliminary results of 15 BLR lag measurements from the Sloan Digital Sky Survey Reverberation Mapping (SDSS-RM) project, a dedicated RM program with multi-object spectroscopy designed for RM over a wide redshift range. The lags are based on the 2014 spectroscopic light curves alone (32 epochs over 6 months) and focus on the Hbeta and MgII broad lines in the 100 lowest-redshift (z0.3 is not yet possible due to the limitations in our current lag sample and selection biases inherent to our program. Our results demonstrate the general feasibility and potential of multi-object RM for z>0.3 quasars, and motivate more intensive spectroscopic and photometric monitoring to derive high-quality lag measurements for these objects...

  4. On the cosmic evolution of the scaling relations between black holes and their host galaxies: Broad Line AGN in the zCOSMOS survey

    CERN Document Server

    Merloni, A; Bolzonella, M; Brusa, M; Civano, F; Comastri, A; Elvis, M; Fiore, F; Gilli, R; Hao, H; Jahnke, K; Koekemoer, A M; Lusso, E; Mainieri, V; Mignoli, M; Miyaji, T; Renzini, A; Salvato, M; Silverman, Joseph; Trump, J; Vignali, C; Zamorani, G; Capak, P; Lilly, S J; Sanders, D; Taniguchi, Y; Bardelli, S; Carollo, C M; Caputi, K; Contini, T; Coppa, G; Cucciati, O; De la Torre, S; de Ravel, L; Franzetti, P; Garilli, B; Hasinger, G; Impey, C; Iovino, A; Iwasawa, K; Kampczyk, P; Kneib, J -P; Knobel, C; Kovac, K; Lamareille, F; Le Borgne, J F; Le Brun, V; Le Fèvre, O; Maier, C; Pellò, R; Peng, Y; Montero, E Perez; Ricciardelli, E; Scodeggio, M; Tanaka, M; Tasca, L A M; Tresse, L; Vergani, D; Zucca, E

    2009-01-01

    (Abriged) We report on the measurement of the rest frame K-band luminosity and total stellar mass of the hosts of 89 broad line Active Galactic Nuclei detected in the zCOSMOS survey in the redshift range 1broad Mg II emission lines observed in the medium-resolution spectra taken with VIMOS/VLT as part of the zCOSMOS project. We found that, as compared to the local value, the average black hole to host galaxy mass ratio appears to evolve positively with redshift, with a best fit evolution of the form (1+z)^{0.68 \\pm0.12 +0.6 -0.3}, where the large asymmetric systematic errors stem from the uncertainties in the choice of IMF, in the calibration of the virial relation used to estimate BH masses and in the mean QSO SED adopted. A thoroug...

  5. Probing the origin of the iron K_alpha line around stellar and supermassive black holes using X-ray polarimetry

    CERN Document Server

    Marin, Frederic

    2013-01-01

    Asymmetric, broad iron lines are a common feature in the X-ray spectra of both X-ray binaries (XRBs) and type-1 Active Galactic Nuclei (AGN). It was suggested that the distortion of the Fe K_alpha emission results from Doppler and relativistic effects affecting the radiative transfer close to the strong gravitational well of the central compact object: a stellar mass black hole (BH) or neutron star (NS) in the case of XRBs, or a super massive black hole (SMBH) in the case of AGN. However, alternative approaches based on reprocessing and transmission of radiation through surrounding media also attempt to explain the line broadening. So far, spectroscopic and timing analyzes have not yet convinced the whole community to discriminate between the two scenarios. Here we study to which extent X-ray polarimetric measurements of black hole X-ray binaries (BHXRBs) and type-1 AGN could help to identify the possible origin of the line distortion. To do so, we report on recent simulations obtained for the two BH flavors ...

  6. A Comprehensive Study of Broad Absorption Line Quasars: I. Prevalence of HeI* Absorption Line Multiplets in Low-Ionization Objects

    CERN Document Server

    Liu, Wen-Juan; Ji, Tuo; Yuan, Weimin; Wang, Ting-Gui; Jian, Ge; Shi, Xiheng; Zhang, Shaohua; Jiang, Peng; Shu, Xinwen; Wang, Huiyuan; Wang, Shu-Fen; Sun, Luming; Yang, Chenwei; Liu, Bo; Zhao, Wen

    2015-01-01

    Neutral Helium multiplets, HeI*3189,3889,10830 are very useful diagnostics to the geometry and physical conditions of the absorbing gas in quasars. So far only a handful of HeI* detections have been reported. Using a newly developed method, we detected HeI*3889 absorption line in 101 sources of a well-defined sample of 285 MgII BAL quasars selected from the SDSS DR5. This has increased the number of HeI* BAL quasars by more than one order of magnitude. We further detected HeI*3189 in 50% (52/101) quasars in the sample. The detection fraction of HeI* BALs in MgII BAL quasars is about 35% as a whole, and increases dramatically with increasing spectral signal-to-noise ratios, from 18% at S/N = 35. This suggests that HeI* BALs could be detected in most MgII LoBAL quasars, provided spectra S/N is high enough. Such a surprisingly high HeI* BAL fraction is actually predicted from photo-ionization calculations based on a simple BAL model. The result indicates that HeI* absorption lines can be used to search for BAL q...

  7. Observations of Relativistically Broadened Iron Kalpha Lines From Stellar Mass Black Holes

    Science.gov (United States)

    Tomsick, John

    2016-04-01

    The measurement of Doppler broadened and gravitationally redshifted iron emission lines from accreting black holes has been used to measure the inner radius of the optically thick disk (Rin). At high mass accretion rates, when the disk is at or close to the Innermost Stable Circular Orbit (ISCO), a determination of Rin provides a constraint on the spin of the black hole. Measuring Rin can also provide information about whether the disk is truncated or not, and this is especially important for understanding the relationship between the disk and the steady jet in the hard state. Over the past few years, the Nuclear Spectroscopic Telescope Array (NuSTAR) has provided improved measurements due to its combination of bandpass (3-79 keV), good energy resolution, and high throughput. In this presentation, we discuss NuSTAR results for a number of stellar mass black holes (e.g., Cyg X-1, GX 339-4, and GRS 1739-278). While these observations have been successful in obtaining measurements of Rin, the improved spectra have also provided extra information about the source geometry and the inner disk inclination, which we will discuss.

  8. Comparison of atomistic and elasticity approaches for carbon diffusion near line defects in {alpha}-iron

    Energy Technology Data Exchange (ETDEWEB)

    Veiga, R.G.A., E-mail: rgaveiga@gmail.com [Universite de Lyon, INSA Lyon, Laboratoire MATEIS, UMR CNRS 5510, 25 Avenue Jean Capelle, F69621, Villeurbanne (France); Perez, M. [Universite de Lyon, INSA Lyon, Laboratoire MATEIS, UMR CNRS 5510, 25 Avenue Jean Capelle, F69621, Villeurbanne (France); Becquart, C.S. [Unite Materiaux et Transformations (UMET), Ecole Nationale Superieure de Chimie de Lille, UMR CNRS 8207, Bat. C6, F59655 Villeneuve d' Ascq Cedex (France); Laboratoire commun EDF-CNRS Etude et Modelisation des Microstructures pour le Vieillissement des Materiaux (EM2VM) (France); Clouet, E. [Service de Recherches de Metallurgie Physique, CEA/Saclay, 91191 Gif-sur-Yvette (France); Domain, C. [EDF, Recherche et Developpement, Materiaux et Mecanique des Composants, Les Renardieres, F77250 Moret sur Loing (France); Laboratoire commun EDF-CNRS Etude et Modelisation des Microstructures pour le Vieillissement des Materiaux (EM2VM) (France)

    2011-10-15

    Energy barriers for carbon migration in the neighborhood of line defects in body-centered cubic iron have been obtained by atomistic simulations. For this purpose, molecular statics with an Fe-C interatomic potential, based on the embedded atom method, has been employed. Results of these simulations have been compared to the predictions of anisotropic elasticity theory. The agreement is better for a carbon atom sitting on an octahedral site (energy minimum) than one on a tetrahedral site (saddle point). Absolute differences in the energy barriers obtained by the two methods are usually below 5 meV at distances larger than 1.5 nm from a screw dislocation and 2 nm (up to 4 nm in the glide plane) from the edge dislocation. Atomistic kinetic Monte Carlo simulations performed at T = 300 K and additional analysis based on the activation energies obtained by both methods show that they are in good qualitative agreement, despite some important quantitative discrepancies due to the large absolute errors found near the dislocation cores.

  9. Iron K$\\alpha$ line of Kerr black holes with scalar hair

    CERN Document Server

    Ni, Yueying; Cardenas-Avendano, Alejandro; Bambi, Cosimo; Herdeiro, Carlos A R; Radu, Eugen

    2016-01-01

    Recently, a family of hairy black holes in 4-dimensional Einstein gravity minimally coupled to a complex, massive scalar field was discovered (Herdeiro & Radu, 2014). Besides the mass $M$ and spin angular momentum $J$, these objects are characterized by a Noether charge $Q$, measuring the amount of scalar hair, which is not associated to a Gauss law and cannot be measured at spatial infinity. Introducing a dimensionless scalar hair parameter $q$, ranging from 0 to 1, we recover (a subset of) Kerr black holes for $q=0$ and a family of rotating boson stars for $q=1$. In the present paper, we explore the possibility of measuring $q$ for astrophysical black holes with current and future X-ray missions. We study the iron K$\\alpha$ line expected in the reflection spectrum of such hairy black holes and we simulate observations with Suzaku and eXTP. As a proof of concept we show, by analyzing a sample of hairy black holes, that current observations can already rule out a region in the space of solutions, because ...

  10. Comparison of atomistic and elasticity approaches for carbon diffusion near line defects in α-iron

    International Nuclear Information System (INIS)

    Energy barriers for carbon migration in the neighborhood of line defects in body-centered cubic iron have been obtained by atomistic simulations. For this purpose, molecular statics with an Fe-C interatomic potential, based on the embedded atom method, has been employed. Results of these simulations have been compared to the predictions of anisotropic elasticity theory. The agreement is better for a carbon atom sitting on an octahedral site (energy minimum) than one on a tetrahedral site (saddle point). Absolute differences in the energy barriers obtained by the two methods are usually below 5 meV at distances larger than 1.5 nm from a screw dislocation and 2 nm (up to 4 nm in the glide plane) from the edge dislocation. Atomistic kinetic Monte Carlo simulations performed at T = 300 K and additional analysis based on the activation energies obtained by both methods show that they are in good qualitative agreement, despite some important quantitative discrepancies due to the large absolute errors found near the dislocation cores.

  11. A quasi-periodic modulation of the iron line centroid energy in the black hole binary H1743-322

    Science.gov (United States)

    Ingram, Adam; van der Klis, Michiel; Middleton, Matthew; Done, Chris; Altamirano, Diego; Heil, Lucy; Uttley, Phil; Axelsson, Magnus

    2016-09-01

    Accreting stellar-mass black holes often show a `Type-C' quasi-periodic oscillation (QPO) in their X-ray flux and an iron emission line in their X-ray spectrum. The iron line is generated through continuum photons reflecting off the accretion disc, and its shape is distorted by relativistic motion of the orbiting plasma and the gravitational pull of the black hole. The physical origin of the QPO has long been debated, but is often attributed to Lense-Thirring precession, a General Relativistic effect causing the inner flow to precess as the spinning black hole twists up the surrounding space-time. This predicts a characteristic rocking of the iron line between red- and blueshift as the receding and approaching sides of the disc are respectively illuminated. Here we report on XMM-Newton and NuSTAR observations of the black hole binary H1743-322 in which the line energy varies systematically over the ˜4 s QPO cycle (3.70σ significance), as predicted. This provides strong evidence that the QPO is produced by Lense-Thirring precession, constituting the first detection of this effect in the strong gravitation regime. There are however elements of our results harder to explain, with one section of data behaving differently than all the others. Our result enables the future application of tomographic techniques to map the inner regions of black hole accretion discs.

  12. A quasi-periodic modulation of the iron line centroid energy in the black hole binary H 1743-322

    CERN Document Server

    Ingram, Adam; Middleton, Matthew; Done, Chris; Altamirano, Diego; Heil, Lucy; Uttley, Phil; Axelsson, Magnus

    2016-01-01

    Accreting stellar-mass black holes often show a `Type-C' quasi-periodic oscillation (QPO) in their X-ray flux, and an iron emission line in their X-ray spectrum. The iron line is generated through continuum photons reflecting off the accretion disk, and its shape is distorted by relativistic motion of the orbiting plasma and the gravitational pull of the black hole. The physical origin of the QPO has long been debated, but is often attributed to Lense-Thirring precession, a General Relativistic effect causing the inner flow to precess as the spinning black hole twists up the surrounding space-time. This predicts a characteristic rocking of the iron line between red and blue shift as the receding and approaching sides of the disk are respectively illuminated. Here we report on XMM-Newton and NuSTAR observations of the black hole binary H 1743-322 in which the line energy varies systematically over the ~4 s QPO cycle (3.70 sigma significance), as predicted. This provides strong evidence that the QPO is produced...

  13. An HST/COS observation of broad Lyα emission and associated absorption lines of the BL Lacertae object H 2356-309

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Taotao [Department of Astronomy and Institute of Theoretical Physics and Astrophysics, Xiamen University, Xiamen, Fujian 361005 (China); Danforth, Charles W.; Stocke, John T.; Shull, J. Michael [CASA, Department of Astrophysical and Planetary Sciences, University of Colorado, 389-UCB, Boulder, CO 80309 (United States); Buote, David A. [Department of Physics and Astronomy, 4129 Frederick Reines Hall, University of California, Irvine, CA 92697 (United States); Canizares, Claude R. [Department of Physics and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Gastaldello, Fabio, E-mail: fangt@xmu.edu.cn [IASF-Milano, INAF, via Bassini 15, Milan I-20133 (Italy)

    2014-11-01

    Weak spectral features in BL Lacertae objects (BL Lacs) often provide a unique opportunity to probe the inner region of this rare type of active galactic nucleus. We present a Hubble Space Telescope/Cosmic Origins Spectrograph observation of the BL Lac H 2356-309. A weak Lyα emission line was detected. This is the fourth detection of a weak Lyα emission feature in the ultraviolet (UV) band in the so-called high-energy peaked BL Lacs, after Stocke et al. Assuming the line-emitting gas is located in the broad line region (BLR) and the ionizing source is the off-axis jet emission, we constrain the Lorentz factor (Γ) of the relativistic jet to be ≥8.1 with a maximum viewing angle of 3.°6. The derived Γ is somewhat larger than previous measurements of Γ ≈ 3-5, implying a covering factor of ∼3% of the line-emitting gas. Alternatively, the BLR clouds could be optically thin, in which case we constrain the BLR warm gas to be ∼10{sup –5} M {sub ☉}. We also detected two H I and one O VI absorption lines that are within |Δv| < 150 km s{sup –1} of the BL Lac object. The O VI and one of the H I absorbers likely coexist due to their nearly identical velocities. We discuss several ionization models and find a photoionization model where the ionizing photon source is the BL Lac object that can fit the observed ion column densities with reasonable physical parameters. This absorber can either be located in the interstellar medium of the host galaxy or in the BLR.

  14. VLT/ISAAC Spectra of the Hbeta Region in Intermediate-Redshift Quasars III. Hbeta Broad Line Profile Analysis and Inferences about BLR Structure

    CERN Document Server

    Marziani, P; Stirpe, G M; Zamfir, S; Calvani, M

    2008-01-01

    [Abridged] We present new VLT ISAAC spectra for 30 quasars, which we combine with previous data to yield a sample of 53 intermediate redshift (z ~ 0.9 - 3.0) sources. The sample is used to explore properties of prominent lines in the Hbeta spectral region of these very luminous quasars. We find two major trends: (1) a systematic increase of minimum FWHM Hbeta with luminosity (discussed in a previous paper). This lower FWHM envelope is best fit assuming that the narrowest sources radiate near the Eddington limit, show line emission from a virialized cloud distribution, and obey a well defined broad line region size vs. luminosity relation. (2) A systematic decrease of equivalent width of [OIII] (from W ~ 15 to ~ 1 A) with increasing source bolometric luminosity (from log L ~ 43 to log L ~ 49). Further identified trends required discrimination between so-called Population A and B sources. We generate median composite spectra in six luminosity bins Pop. A sources show reasonably symmetric Lorentzian Hbeta profil...

  15. The Broad-Lined Type Ic SN 2012ap and the Nature of Relativistic Supernovae Lacking a Gamma-ray Burst Detection

    CERN Document Server

    Milisavljevic, D; Parrent, J T; Soderberg, A M; Fesen, R A; Mazzali, P; Maeda, K; Sanders, N E; Cenko, S B; Silverman, J M; Filippenko, A V; Kamble, A; Chakraborti, S; Drout, M R; Kirshner, R P; Pickering, T E; Kawabata, K; Hattori, T; Hsiao, E Y; Stritzinger, M D; Marion, G H; Vinko, J; Wheeler, J C

    2014-01-01

    We present ultraviolet, optical, and near-infrared observations of SN 2012ap, a broad-lined Type Ic supernova in the galaxy NGC 1729 that produced a relativistic and rapidly decelerating outflow without a gamma-ray burst signature. Photometry and spectroscopy follow the flux evolution from -13 to +272 days past the B-band maximum of -17.4 +/- 0.5 mag. The spectra are dominated by Fe II, O I, and Ca II absorption lines at ejecta velocities of 20,000 km/s that change slowly over time. Other spectral absorption lines are consistent with contributions from photospheric He I, and hydrogen may also be present at higher velocities (> 27,000 km/s). We use these observations to estimate explosion properties and derive a total ejecta mass of 2.7 Msolar, a kinetic energy of 1.0x10^{52} erg, and a 56Ni mass of 0.1-0.2 Msolar. Nebular spectra (t > 200d) exhibit an asymmetric double-peaked [OI] 6300,6364 emission profile that we associate with absorption in the supernova interior, although toroidal ejecta geometry is an al...

  16. IRAS 13197-1627 has them all: Compton-thin absorption, photo-ionized gas, thermal plasmas, and a broad Fe line

    CERN Document Server

    Miniutti, G; Dadina, M; Cappi, M; Malaguti, G

    2006-01-01

    We report results from the XMM-Newton observation of IRAS 13197-1627, a luminous IR galaxy with a Seyfert 1.8 nucleus. The hard X-ray spectrum is steep and is absorbed by Compton-thin neutral gas. We detect an Fe emission line at 6.4 keV, consistent with transmission through the absorber. The most striking result of our spectral analysis is the detection of a dominant X-ray reflection component and broad Fe line from the inner accretion disc. The reflection-dominated hard X-ray spectrum is confirmed by the strong Compton hump seen in a previous BeppoSAX observation and could be the sign that most of the primary X-rays are radiated from a compact corona (or e.g. base of the jet) within a few gravitational radii from the black hole. We also detect a relatively strong absorption line at 6.81 keV which, if interpreted as Fe xxv resonant absorption intrinsic to the source, implies an outflow with velocity of about 5000 km/s. In the soft energy band, the high-resolution RGS and the CCD-resolution data show the pres...

  17. Steps toward determination of the size and structure of the broad-line region in active nuclei. 7: Variability of the optical spectrum of NGC 5548 over years

    Science.gov (United States)

    Peterson, B. M.; Berlind, P.; Bertram, R.; Bochkarev, N. G.; Bond, D.; Brotherton, M. S.; Busler, J. R.; Chuvaev, K. K.; Cohen, R. D.; Dietrich, M.

    1994-01-01

    We report on the results of a continuation of a large monitoring program of optical spectroscopy of the Seyfert 1 galaxy NGC 5548. The new observations presented here were obtained between 1990 December and 1992 October, and extend the existing database to nearly 1400 days, dating back to 1988 December. The continuum variations are generally smooth and well-resolved, except during the third year of this 4 year project, when the variations were apparently more rapid and of lower amplitude than observed at other times. The broad H(beta) emission line is found to vary in response to the continuum variations with a lag of about 18 days, but with some changes from year to year. The H(beta) transfer functions for each of the 4 yr and for the entire 4 yr database are derived by using a maximum entropy method.

  18. Discovery of a broad O VIII Ly alpha line in the ultra-compact X-ray binary 4U 1543-624

    CERN Document Server

    Madej, O K

    2010-01-01

    We report the discovery of a broad emission feature at ~0.7 keV in the spectra of the ultra-compact X-ray binary 4U 1543-624, obtained with the high-resolution spectrographs of the XMM-Newton and Chandra satellites. We confirm the presence of the feature in the broad band MOS2 spectrum of the source. As suggested before in the literature, the donor star in this source is a CO or ONe white dwarf, which transfers oxygen-rich material to the accretor, conceivably a neutron star. The X-rays reprocessed in this oxygen-rich accretion disc could give a reflection spectrum with O VIII Ly alpha as the most prominent emission line. Apart from the feature at ~0.7 keV we confirm the possible presence of a weak emission feature at ~6.6 keV, which was reported in the literature for this data set. We interpret the feature at ~0.7 keV and ~6.6 keV as O VIII Ly alpha and Fe K alpha emission respectively, caused by X-rays reflected off the accretion disc in the strong gravitational field close to the accretor.

  19. Suzaku discovery of iron absorption lines in outburst spectra of the X-ray transient 4U 1630-472

    CERN Document Server

    Kubota, A; Cottam, J; Kotani, T; Done, C; Ueda, Y; Fabian, A C; Yasuda, T; Takahashi, H; Fukazawa, Y; Yamaoka, K; Makishima, K; Yamada, S; Kohmura, T; Angelini, L; Kubota, Aya; Dotani, Tadayasu; Cottam, Jean; Kotani, Taro; Done, Chris; Ueda, Yoshihiro; Fabian, Andrew C.; Yasuda, Tomonori; Takahashi, Hiromitsu; Fukazawa, Yasushi; Yamaoka, Kazutaka; Makishima, Kazuo; Yamada, Shinya; Kohmura, Takayoshi; Angelini, Lorella

    2006-01-01

    We present the results of six Suzaku observations of the recurrent black hole transient 4U1630-472 during its decline from outburst from February 8 to March 23 in 2006. All observations show the typical high/soft state spectral shape in the 2-50keV band, roughly described by an optically thick disk spectrum in the soft energy band plus a weak power-law tail that becomes dominant only above \\~20keV. The disk temperature decreases from 1.4keV to 1.2keV as the flux decreases by a factor 2, consistent with a constant radius as expected for disk-dominated spectra. All the observations reveal significant absorption lines from highly ionized (H-like and He-like) iron Ka at 7.0keV and 6.7keV. The brightest datasets also show significant but weaker absorption structures between 7.8keV and 8.2keV, which we identify as a blend of iron Kb and nickel Ka absorption lines. The energies of these absorption lines suggest a blue shift with an outflow velocity of ~1000km/s.. The H-like iron Ka equivalent width remains approxima...

  20. SHORT-TIMESCALE MONITORING OF THE X-RAY, UV, AND BROAD DOUBLE-PEAK EMISSION LINE OF THE NUCLEUS OF NGC 1097

    Energy Technology Data Exchange (ETDEWEB)

    Schimoia, Jaderson S.; Storchi-Bergmann, Thaisa [Instituto de Física, Universidade Federal do Rio Grande do Sul, Campus do Vale, Porto Alegre, RS (Brazil); Grupe, Dirk [Space Science Center, Morehead State University, 235 Martindale Drive, Morehead, KY 40351 (United States); Eracleous, Michael [Department of Astronomy and Astrophysics and Institute for Gravitation and the Cosmos, Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States); Peterson, Bradley M. [Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Baldwin, Jack A. [Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48864 (United States); Nemmen, Rodrigo S. [Instituto de Astronomia, Geofísica e Ciências Atmosféricas, Universidade de São Paulo, São Paulo, SP 05508-090 (Brazil); Winge, Cláudia, E-mail: silva.schimoia@ufrgs.br [Gemini South Observatory, c/o AURA Inc., Casilla 603, La Serena (Chile)

    2015-02-10

    Recent studies have suggested that the short-timescale (≲ 7 days) variability of the broad (∼10,000 km s{sup –1}) double-peaked Hα profile of the LINER nucleus of NGC 1097 could be driven by a variable X-ray emission from a central radiatively inefficient accretion flow. To test this scenario, we have monitored the NGC 1097 nucleus in X-ray and UV continuum with Swift and the Hα flux and profile in the optical spectrum using SOAR and Gemini-South from 2012 August to 2013 February. During the monitoring campaign, the Hα flux remained at a very low level—three times lower than the maximum flux observed in previous campaigns and showing only limited (∼20%) variability. The X-ray variations were small, only ∼13% throughout the campaign, while the UV did not show significant variations. We concluded that the timescale of the Hα profile variation is close to the sampling interval of the optical observations, which results in only a marginal correlation between the X-ray and Hα fluxes. We have caught the active galaxy nucleus in NGC 1097 in a very low activity state, in which the ionizing source was very weak and capable of ionizing just the innermost part of the gas in the disk. Nonetheless, the data presented here still support the picture in which the gas that emits the broad double-peaked Balmer lines is illuminated/ionized by a source of high-energy photons which is located interior to the inner radius of the line-emitting part of the disk.

  1. Characterizing the Iron Wash fault: A fault line scarp in Utah

    Science.gov (United States)

    Kozaci, O.; Ostenaa, D.; Goodman, J.; Zellman, M.; Hoeft, J.; Sowers, J. M.; Retson, T.

    2015-12-01

    The Iron Wash fault (IWF) is an approximately 30 mile-long, NW-SE trending structure, oriented perpendicular to the San Rafael Monocline near Green River in Utah. IWF exhibits well-expressed geomorphic features such as a linear escarpment with consistently north side down displacement. The fault coincides with an abrupt change in San Rafael Monocline dip angle along its eastern margin. The IWF is exposed in incised drainages where Jurassic Navajo sandstone (oldest) and Lower Carmel Formation (old), are juxtaposed against Jurassic Entrada sandstone (younger) and Quaternary alluvium (youngest). To assess the recency of activity of the IWF we performed detailed geomorphic mapping and a paleoseismic trenching investigation. A benched trench was excavated across a Quaternary fluvial terrace remnant across the mapped trace of the IWF. The uppermost gravel units and overlying colluvium are exposed in the trench across the projection of the fault. In addition, we mapped the basal contact of the Quaternary gravel deposit in relation to the adjacent fault exposures in detail to show the geometry of the basal contact near and across the fault. We find no evidence of vertical displacement of these Quaternary gravels. A preliminary U-series date of calcite cementing unfaulted fluvial gravels and OSL dating of a sand lens within the unfaulted fluvial gravels yielded approximately 304,000 years and 78,000 years, respectively. These preliminary results of independent dating methods constrains the timing of last activity of the IWF to greater than 78,000 years before present suggesting that IWF not an active structure. Its distinct geomorphic expression is most likely the result of differential erosion, forming a fault-line scarp.

  2. Influence of laser pulse energy on emission lines intensity in the femtosecond laser-induced breakdown spectroscopy of iron in aqua solution

    Science.gov (United States)

    Golik, S. S.; Ilyin, A. A.; Babiy, M. Y.; Biryukova, Yu. S.; Lisitsa, V. V.; Shmirko, K. A.

    2015-11-01

    The influence of pulse energy on the time evolution of the intensity of the continuum and emission lines of plasma generated on the surface of aqueous solutions of iron by focused radiation Ti: sapphire laser with a wavelength of 800 nm and pulse duration of 45 fs and a range of energy 3-7 mJ was investigated. The calibration curve for iron in water and 3-ó limit of detection of iron in water was obtained.

  3. The Seyfert 2 Galaxy NGC 2110: Hard X-Ray Emission Observed by NuStar and Variability of the Iron K-Alpha Line

    Science.gov (United States)

    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).

  4. The size of the X-ray emitting region in SWIFT J2127.4+5654 via a broad line region cloud X-ray eclipse

    CERN Document Server

    Sanfrutos, Mario; Agís-González, Beatriz; Fabian, Andy C; Miller, Jon M; Panessa, Francesca; Zoghbi, Abderahmen

    2013-01-01

    We present results obtained from the time-resolved X-ray spectral analysis of the Narrow-Line-Seyfert 1 galaxy SWIFT J2127.4+5654 during a ~130 ks XMM-Newton observation. We reveal large spectral variations, especially during the first ~90 ks of the XMM-Newton exposure. The spectral variability can be attributed to a partial eclipse of the X-ray source by an intervening low-ionization/cold absorbing structure (cloud) with column density N_H = 2.0^{+0.2}_{-0.3}e22 cm^-2 which gradually covers and then uncovers the X-ray emitting region with covering fraction ranging from zero to ~43 per cent. Our analysis enables us to constrain the size, number density, and location of the absorbing cloud with good accuracy. We infer a cloud size (diameter) of $D_c 1.5e9 cm^-3 at a distance of R_c > 4.3e16 cm from the central black hole. All of the inferred quantities concur to identify the absorbing structure with one single cloud associated with the broad line region of SWIFT J2127.4+5654. We are also able to constrain the...

  5. An experimental observation of the different behavior of ionic and neutral lines of iron as a function of number density in a binary carbon–iron mixture

    Energy Technology Data Exchange (ETDEWEB)

    Sivakumar, P.; Taleh, L.; Markushin, Y. [Optical Science Center for Applied Research and Applications, Department of Physics and Pre-Engineering, Delaware State University, Dover, DE 19901 (United States); Melikechi, N., E-mail: nmelikechi@desu.edu [Optical Science Center for Applied Research and Applications, Department of Physics and Pre-Engineering, Delaware State University, Dover, DE 19901 (United States); Lasue, J. [Université de Toulouse, UPS-OMP, IRAP, 9 Av. Colonel Roche, BP 44346, F-31028 Toulouse Cedex 4 (France); ISR, MS D466, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Lunar and Planetary Institute, 3600 Bay Area Boulevard, Houston, TX 77058 (United States)

    2013-04-01

    We report on the dependence of the intensities of atomic and ionic lines emitted by a nanosecond laser-induced plasma on the atomic number densities of the constituents of a binary mixture formed of carbon and iron. We show that the packing density of the sample greatly affects the relative standard deviation of the emission lines. Furthermore, we show that the variation of the intensities of the C and Fe emission lines depends in a non-trivial way on the relative C–Fe concentration. The intensities of Fe neutral atomic lines behave differently than those of the ionic ones particularly at and above concentrations of 75%–80% Fe embedded in a carbon matrix. Unlike the emission from neutral Fe, those from ionic Fe yield a very sharp decrease followed by an equally strong increase of the emission lines over a relatively small range of relative concentration of C and Fe. To better investigate this effect, we have compared the results obtained with nanosecond-LIBS to those with femtosecond-LIBS and found that this phenomenon disappears. The physical interpretation of the sharp decrease followed by an equally sharp increase in the emission intensities from Fe ions as the concentration of Fe is increased requires more studies. - Highlights: ► The effects of the size of the particles on the fluctuations of the LIBS signals ► The variation of LIBS signals with the concentrations of Fe embedded in C is nontrivial. ► The intensities of neutral atomic lines can behave differently than those of ions.

  6. An experimental observation of the different behavior of ionic and neutral lines of iron as a function of number density in a binary carbon–iron mixture

    International Nuclear Information System (INIS)

    We report on the dependence of the intensities of atomic and ionic lines emitted by a nanosecond laser-induced plasma on the atomic number densities of the constituents of a binary mixture formed of carbon and iron. We show that the packing density of the sample greatly affects the relative standard deviation of the emission lines. Furthermore, we show that the variation of the intensities of the C and Fe emission lines depends in a non-trivial way on the relative C–Fe concentration. The intensities of Fe neutral atomic lines behave differently than those of the ionic ones particularly at and above concentrations of 75%–80% Fe embedded in a carbon matrix. Unlike the emission from neutral Fe, those from ionic Fe yield a very sharp decrease followed by an equally strong increase of the emission lines over a relatively small range of relative concentration of C and Fe. To better investigate this effect, we have compared the results obtained with nanosecond-LIBS to those with femtosecond-LIBS and found that this phenomenon disappears. The physical interpretation of the sharp decrease followed by an equally sharp increase in the emission intensities from Fe ions as the concentration of Fe is increased requires more studies. - Highlights: ► The effects of the size of the particles on the fluctuations of the LIBS signals ► The variation of LIBS signals with the concentrations of Fe embedded in C is nontrivial. ► The intensities of neutral atomic lines can behave differently than those of ions

  7. Properties of long-term optical variability of active galactic nuclei with double-peaked broad low-ionization emission lines

    CERN Document Server

    Zhang, XueGuang

    2016-01-01

    In this manuscript, we study properties of long-term optical variability of a large sample of 106 SDSS spectroscopically confirmed AGN with double-peaked broad low-ionization emission lines (double-peaked emitters). The long-term optical light curves over 8 years are collected from the Catalina Sky Surveys Data Release 2. And, the Damped Random Walk (DRW) process is applied to describe the long-term variability of the double-peaked emitters. Meanwhile, the same DRW process is applied to long-term optical light curves of more than 7000 spectroscopically confirmed normal quasars in the SDSS Stripe82 Database. Then, we can find that the DRW process determined rest-frame intrinsic variability timescales $\\ln(\\tau/{\\rm days})$ are about 5.8 and about 4.8 for the double-peaked emitters and for the normal quasars, respectively. The statistically longer intrinsic variability timescales can be confirmed in the double-peaked emitters, after considerations of necessary effects, such as the effects from different distrib...

  8. Herschel-ATLAS: the far-infrared properties and star-formation rates of broad absorption line quasi-stellar objects

    CERN Document Server

    Orjales, J M Cao; Jarvis, M J; Smith, D J B; Hardcastle, M J; Auld, R; Baes, M; Cava, A; Clements, D L; Cooray, A; Coppin, K; Dariush, A; De Zotti, G; Dunne, L; Dye, S; Eales, S; Hopwood, R; Hoyos, C; Ibar, E; Ivison, R J; Maddox, S; Page, M J; Valiante, E

    2012-01-01

    We have used data from the Herschel-ATLAS at 250, 350 and 500 \\mu m to determine the far-infrared (FIR) properties of 50 Broad Absorption Line Quasars (BAL QSOs). Our sample contains 49 high-ionization BAL QSOs (HiBALs) and 1 low-ionization BAL QSO (LoBAL) which are compared against a sample of 329 non-BAL QSOs. These samples are matched over the redshift range 1.5 \\leq z 5 sigma level. We calculate star-formation rates (SFR) for our individually detected HiBAL QSOs and the non-detected LoBAL QSO as well as average SFRs for the BAL and non-BAL QSO samples based on stacking the Herschel data. We find no difference between the HiBAL and non-BAL QSO samples in the FIR, even when separated based on differing BAL QSO classifications. Using Mrk 231 as a template, the weighted mean SFR is estimated to be \\approx240\\pm21 M_{\\odot} yr^{-1} for the full sample, although this figure should be treated as an upper limit if AGN-heated dust makes a contribution to the FIR emission. Despite tentative claims in the literatur...

  9. Optical Follow-Up Observations of PTF10qts, a Luminous Broad-Lined Type Ic Supernova Found by the Palomar Transient Factory

    CERN Document Server

    Walker, E S; Pian, E; Hurley, K; Arcavi, I; Cenko, S B; Gal-Yam, A; Horesh, A; Kasliwal, M; Poznanski, D; Silverman, J M; Sullivan, M; Bloom, J S; Filippenko, A V; Kulkarni, S R; Nugent, P E; Ofek, E; Barthelmy, S; Boynton, W; Goldsten, J; Golenetskii, S; Ohno, M; Tashiro, M S; Yamaoka, K; Zhang, X L-

    2014-01-01

    We present optical photometry and spectroscopy of the broad-lined Type Ic supernova (SNIc-BL) PTF10qts, which was discovered as part of the Palomar Transient Factory. The supernova was located in a dwarf galaxy of magnitude $r=21.1$ at a redshift $z=0.0907$. We find that the $R$-band light curve is a poor proxy for bolometric data and use photometric and spectroscopic data to construct and constrain the bolometric light curve. The derived bolometric magnitude at maximum light is $M_{\\rm bol} = -18.51\\pm0.2$ mag, comparable to that of SN 1998bw ($M_{\\rm bol} = -18.7$ mag) which was associated with a gamma-ray burst (GRB). PTF10qts is one of the most luminous SNIc-BL observed without an accompanying GRB. We estimate the physical parameters of the explosion using data from our programme of follow-up observations, finding that it produced a larger mass of radioactive nickel compared to other SNeIc-BL with similar inferred ejecta masses and kinetic energies. The progenitor of the event was likely a $\\sim20$M$_{\\od...

  10. Application of the spine-layer jet radiation model to outbursts in the broad-line radio galaxy 3C 120

    CERN Document Server

    Janiak, Mateusz; Moderski, Rafal

    2015-01-01

    We present a detailed Fermi/LAT data analysis for the broad-line radio galaxy 3C 120. This source has recently entered into a state of increased gamma-ray activity which manifested itself in two major flares detected by Fermi/LAT in September 2014 and April 2015 with no significant flux changes reported in other wavelengths. We analyse available data focusing our attention on aforementioned outbursts. We find very fast variability timescale during flares (of the order of hours) together with a significant gamma-ray flux increase. We show that the 6.8 years averaged gamma-ray emission of 3C 120 is likely a sum of the external radiation Compton and the synchrotron self-Compton radiative components. To address the problem of "orphan" gamma-ray flares and fast variability we model the jet radiation dividing the jet structure into two components: the wide and relatively slow outer layer and the fast, narrow spine. We show that with the addition of the fast spine occasionally bent towards the observer we are able t...

  11. Weak Hard X-ray Emission from Two Broad Absorption Line Quasars Observed with NuSTAR: Compton-thick Absorption or Intrinsic X-ray Weakness?

    CERN Document Server

    Luo, B; Alexander, D M; Harrison, F A; Stern, D; Bauer, F E; Boggs, S E; Christensen, F E; Comastri, A; Craig, W W; Fabian, A C; Farrah, D; Fiore, F; Fuerst, F; Grefenstette, B W; Hailey, C J; Hickox, R; Madsen, K K; Matt, G; Ogle, P; Risaliti, G; Saez, C; Teng, S H; Walton, D J; Zhang, W W

    2013-01-01

    We present NuSTAR hard X-ray observations of two X-ray weak broad absorption line (BAL) quasars, PG 1004+130 (radio loud) and PG 1700+518 (radio quiet). Many BAL quasars appear X-ray weak, probably due to absorption by the shielding gas between the nucleus and the accretion-disk wind. The two targets are among the optically brightest BAL quasars, yet they are known to be significantly X-ray weak at rest-frame 2-10 keV (16-120 times fainter than typical quasars). We would expect to obtain ~400-600 hard X-ray (>10 keV) photons with NuSTAR, provided that these photons are not significantly absorbed (NH<1E24 cm^{-2}). However, both BAL quasars are only detected in the softer NuSTAR bands (e.g., 4-20 keV) but not in its harder bands (e.g., 20-30 keV), suggesting that either the shielding gas is highly Compton-thick or the two targets are intrinsically X-ray weak. We constrain the column densities for both to be NH~7E24 cm^{-2} if the weak hard X-ray emission is caused by obscuration from the shielding gas. We d...

  12. The Spectral SN-GRB Connection: Systematic Spectral Comparisons between Type Ic Supernovae, broad-lined Type Ic Supernovae with and without Gamma-Ray Bursts

    CERN Document Server

    Modjaz, Maryam; Bianco, Federica B; Graur, Or

    2015-01-01

    We present the first systematic investigation of spectral properties of 17 Type Ic Supernovae (SNe Ic), 10 broad-lined SNe Ic (SNe Ic-bl) without observed Gamma-Ray Bursts (GRBs) and 10 SNe Ic-bl with GRBs (SN-GRBs) as a function of time in order to probe their explosion conditions and progenitors. We analyze a total of 396 spectra, which were drawn from published spectra of individual SNe as well as from the densely time-sampled spectra data of Modjaz et al. (2014). In order to quantify the diversity of the SN spectra as a function of SN subtype, we construct average spectra of SNe Ic, SNe Ic-bl without GRBs and SNe Ic-bl with GRBs, along with standard deviation and maximum deviation contours. We find that SN~1994I is not a typical SN Ic, in contrast to common belief, while the spectra of SN 1998bw/GRB 980425 are representative of mean spectra of SNe Ic-bl. We measure the ejecta absorption and width velocities (as traced by FeII 5169) and find that SNe Ic-bl with GRBs, on average, have quantifiably higher ab...

  13. On the disappearance of broad-line region in low-luminosity active galactic nuclei: the role of the outflows from advection dominated accretion flows

    CERN Document Server

    Cao, Xinwu

    2010-01-01

    The broad-line region (BLR) disappears in many low-luminosity AGNs, the reason of which is still controversial. The BLRs in AGNs are believed to be associated with the outflows from the accretion disks. Most of the low-luminosity AGNs (LLAGNs) contain advection dominated accretion flows (ADAFs), which are very hot and have a positive Bernoulli parameter. ADAFs are therefore associated with strong outflows. We estimate the cooling of the outflows from the ADAFs, and find that the gases in such hot outflows always cannot be cooled efficiently by bremsstrahlung radiation. The ADAF may co-exist with the standard disk, i.e., the inner ADAF connects to the outer thin accretion disk at radius R_tr, in the sources accreting at slightly lower than the critical rate. For the ADAFs with >0.001 L_edd, a secondary small inner cold disk is suggested to co-exist with the ADAF due to the condensation process. We estimate the Compton cooling of the outflow, of which the soft seed photons either come from the outer cold disk o...

  14. Quasi-periodic oscillations as a tool for testing the Kerr metric: A comparison with gravitational waves and iron line

    CERN Document Server

    Bambi, Cosimo

    2016-01-01

    QPOs are a common feature in the X-ray power density spectrum of black hole binaries and a potentially powerful tool to probe the spacetime geometry around these objects. Here we discuss their constraining power to test the Kerr black hole hypothesis within the relativistic precession model. We compare our results with the constraints that can be obtained from gravitational waves and iron line. We find that QPOs may provide very precise measurements, but they are strongly affected by parameter degeneracy, and it is difficult to test the Kerr metric with this approach in the absence of independent observations to constrain the mass or the spin.

  15. The soft component and the iron line as signatures of the disc inner radius in Galactic black hole binaries

    OpenAIRE

    Kolehmainen, M.; Done, C.; Díaz Trigo, M.

    2013-01-01

    The inner radius of the accretion disc around a black hole in the low/hard state can be measured in one of two ways. First, via the extent of broadening of the iron emission line, and secondly, from the luminosity and temperature of the weak soft component seen in this state, assuming it is the disc. We use both of these methods on all the low/hard state spectra taken in timing mode of XMM–Newton's EPIC-pn. We find that the two methods are not consistent with each other, and the difference is...

  16. The Broad-Lined Type Ic SN 2012ap and the Nature of Relativistic Supernovae Lacking a Gamma-Ray Burst Detection

    Science.gov (United States)

    Milisavljevic, D.; Margutti, R.; Parrent, J. T.; Soderberg, A. M.; Fesen, R. A.; Mazzali, P.; Maeda, K.; Sanders, N. E.; Cenko, S. B.; Silverman, J. M.

    2014-01-01

    We present ultraviolet, optical, and near-infrared observations of SN2012ap, a broad-lined Type Ic supernova in the galaxy NGC 1729 that produced a relativistic and rapidly decelerating outflow without a gamma-ray burst signature. Photometry and spectroscopy follow the flux evolution from -13 to +272 days past the B-band maximum of -17.4 +/- 0.5 mag. The spectra are dominated by Fe II, O I, and Ca II absorption lines at ejecta velocities of v approx. 20,000 km s(exp. -1) that change slowly over time. Other spectral absorption lines are consistent with contributions from photospheric He I, and hydrogen may also be present at higher velocities (v approx. greater than 27,000 km s(exp. -1)). We use these observations to estimate explosion properties and derive a total ejecta mass of 2.7 Solar mass, a kinetic energy of 1.0×1052 erg, and a (56)Ni mass of 0.1-0.2 Solar mass. Nebular spectra (t > 200 d) exhibit an asymmetric double-peaked [O I] lambda lambda 6300, 6364 emission profile that we associate with absorption in the supernova interior, although toroidal ejecta geometry is an alternative explanation. SN2012ap joins SN2009bb as another exceptional supernova that shows evidence for a central engine (e.g., black-hole accretion or magnetar) capable of launching a non-negligible portion of ejecta to relativistic velocities without a coincident gamma-ray burst detection. Defining attributes of their progenitor systems may be related to notable properties including above-average environmental metallicities of Z approx. greater than Solar Z, moderate to high levels of host-galaxy extinction (E(B -V ) > 0.4 mag), detection of high-velocity helium at early epochs, and a high relative flux ratio of [Ca II]/[O I] > 1 at nebular epochs. These events support the notion that jet activity at various energy scales may be present in a wide range of supernovae.

  17. THE BROAD-LINED Type Ic SN 2012ap AND THE NATURE OF RELATIVISTIC SUPERNOVAE LACKING A GAMMA-RAY BURST DETECTION

    Energy Technology Data Exchange (ETDEWEB)

    Milisavljevic, D.; Margutti, R.; Parrent, J. T.; Soderberg, A. M.; Sanders, N. E.; Kamble, A.; Chakraborti, S.; Drout, M. R.; Kirshner, R. P. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Fesen, R. A. [Department of Physics and Astronomy, Dartmouth College, 6127 Wilder Laboratory, Hanover, NH 03755 (United States); Mazzali, P. [Astrophysics Research Institute, Liverpool John Moores University, Liverpool L3 5RF (United Kingdom); Maeda, K. [Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan); Cenko, S. B. [Astrophysics Science Division, NASA Goddard Space Flight Center, Mail Code 661, Greenbelt, MD 20771 (United States); Silverman, J. M. [University of Texas at Austin, 1 University Station C1400, Austin, TX 78712-0259 (United States); Filippenko, A. V. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Pickering, T. E. [Southern African Large Telescope, P.O. Box 9, Observatory 7935, Cape Town (South Africa); Kawabata, K. [Hiroshima Astrophysical Science Center, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Hattori, T. [Subaru Telescope, National Astronomical Observatory of Japan, Hilo, HI 96720 (United States); Hsiao, E. Y. [Carnegie Observatories, Las Campanas Observatory, Colina El Pino, Casilla 601 (Chile); Stritzinger, M. D., E-mail: dmilisav@cfa.harvard.edu [Department of Physics and Astronomy, Aarhus University, Ny Munkegade, DK-8000 Aarhus C (Denmark); and others

    2015-01-20

    We present ultraviolet, optical, and near-infrared observations of SN 2012ap, a broad-lined Type Ic supernova in the galaxy NGC 1729 that produced a relativistic and rapidly decelerating outflow without a gamma-ray burst signature. Photometry and spectroscopy follow the flux evolution from –13 to +272 days past the B-band maximum of –17.4 ± 0.5 mag. The spectra are dominated by Fe II, O I, and Ca II absorption lines at ejecta velocities of v ≈ 20,000 km s{sup –1} that change slowly over time. Other spectral absorption lines are consistent with contributions from photospheric He I, and hydrogen may also be present at higher velocities (v ≳ 27,000 km s{sup –1}). We use these observations to estimate explosion properties and derive a total ejecta mass of ∼2.7 M {sub ☉}, a kinetic energy of ∼1.0 × 10{sup 52} erg, and a {sup 56}Ni mass of 0.1-0.2 M {sub ☉}. Nebular spectra (t > 200 days) exhibit an asymmetric double-peaked [O I] λλ6300, 6364 emission profile that we associate with absorption in the supernova interior, although toroidal ejecta geometry is an alternative explanation. SN 2012ap joins SN 2009bb as another exceptional supernova that shows evidence for a central engine (e.g., black hole accretion or magnetar) capable of launching a non-negligible portion of ejecta to relativistic velocities without a coincident gamma-ray burst detection. Defining attributes of their progenitor systems may be related to notable observed properties including environmental metallicities of Z ≳ Z {sub ☉}, moderate to high levels of host galaxy extinction (E(B – V) > 0.4 mag), detection of high-velocity helium at early epochs, and a high relative flux ratio of [Ca II]/[O I] >1 at nebular epochs. These events support the notion that jet activity at various energy scales may be present in a wide range of supernovae.

  18. BeppoSAX observations of Narrow-Line Seyfert 1 galaxies II. Ionized iron features in Arakelian 564

    CERN Document Server

    Comastri, A; Vignali, C; Brandt, W N; Leighly, K M; Fiore, F; Guainazzi, M; Matt, G; Nicastro, F; Puchnarewicz, E M; Siemiginowska, A L

    2000-01-01

    The BeppoSAX observations of the bright Narrow-Line Seyfert 1 galaxy Ark 564 are presented along with a high quality optical spectrum taken at the 1.5m telescope at La Silla. The 0.1-10 keV X-ray spectrum is characterized by a strong soft component which is best described by blackbody-like emission with a temperature of about 160 eV. At higher energies a steep (Gamma = 2.4) power-law tail is present. There is evidence of an ionized reflector in the form of an iron line and edge. We do not find significant evidence of soft X-ray features if the spectrum is modelled with a two component continuum. The optical and X-ray spectral properties support the hypothesis of a high accretion rate onto a low mass black hole.

  19. Iron Kα Emission Lines in Seyfert(-Like) Active Galactic Nuclei: Revelation of a Rapidly Spinning Central Black Hole

    Institute of Scientific and Technical Information of China (English)

    马振国

    2002-01-01

    Fe Kα lines are superimposed upon the x-ray continuum in most Seyfert(-like) active galactic nuclei (AGNs).By a data-fitting study, previous authors have claimed that the central black hole (BH) is either rotating ornon-rotating according to the thin disc model. We develop the disc model to the torus model to determine thereal spin of the BH. With formulations of the motion of both torus particles and photons near a BH in Kerrmetric, we simulate iron emission linesfrom a thin luminous torus. It is found that only spinning BH galaxiescan radiate observable profiles. The data-fitting to Fe lines of four AGNs observed by ASCA predicts that thecentral BH is spinning rapidly with the dimensionless specific angular momentum approaching the maximalvalueof 1.

  20. Weak Hard X-Ray Emission from Two Broad Absorption Line Quasars Observed with NuStar: Compton-Thick Absorption or Intrinsic X-Ray Weakness?

    Science.gov (United States)

    Luo, B.; Brandt, W. N.; Alexander, D. M.; Harrison, F. A.; Stern, D.; Bauer, F. E.; Boggs, S. E.; Christensen, F. E.; Comastri, A.; Craig, W. W..; Fabian, A. C.; Farrah, D.; Fiore, F.; Fuerst, F.; Grefenstette, B. W.; Hailey, C. J.; Hickox, R.; Madsen, K. K.; Matt, G.; Ogle, P.; Risaliti, G.; Saez, C.; Teng, S. H.; Walton, D. J.; Zhang, W. W.

    2013-01-01

    We present Nuclear Spectroscopic Telescope Array (NuSTAR) hard X-ray observations of two X-ray weak broad absorption line (BAL) quasars, PG 1004+130 (radio loud) and PG 1700+518 (radio quiet). Many BAL quasars appear X-ray weak, probably due to absorption by the shielding gas between the nucleus and the accretion-disk wind. The two targets are among the optically brightest BAL quasars, yet they are known to be significantly X-ray weak at rest-frame 2-10 keV (16-120 times fainter than typical quasars). We would expect to obtain approx. or equal to 400-600 hard X-ray (is greater than or equal to 10 keV) photons with NuSTAR, provided that these photons are not significantly absorbed N(sub H) is less than or equal to 10(exp24) cm(exp-2). However, both BAL quasars are only detected in the softer NuSTAR bands (e.g., 4-20 keV) but not in its harder bands (e.g., 20-30 keV), suggesting that either the shielding gas is highly Compton-thick or the two targets are intrinsically X-ray weak. We constrain the column densities for both to be N(sub H) 7 × 10(exp 24) cm(exp-2) if the weak hard X-ray emission is caused by obscuration from the shielding gas. We discuss a few possibilities for how PG 1004+130 could have Compton-thick shielding gas without strong Fe Ka line emission; dilution from jet-linked X-ray emission is one likely explanation. We also discuss the intrinsic X-ray weakness scenario based on a coronal-quenching model relevant to the shielding gas and disk wind of BAL quasars. Motivated by our NuSTAR results, we perform a Chandra stacking analysis with the Large Bright Quasar Survey BAL quasar sample and place statistical constraints upon the fraction of intrinsically X-ray weak BAL quasars; this fraction is likely 17%-40%.

  1. Emission Lines of Boron, Carbon, Oxygen and Iron in Tokamak Plasma

    Institute of Scientific and Technical Information of China (English)

    DI Long; WAN Bao-Nian; ZHAO Gang; ZHANG Jie; SHI Jian-Rong; WANG Shou-Jun; DONG Quan-Li; ZHAO Jing; LI Yu-Tong; FU Jia; WANG Fu-Di; SHI Yue-Jiang

    2011-01-01

    The emission lines of B,C,O and Fe in tokamak plasma are reported. The spectra are compared with those calculated by the CHIANTI code,which is based on the collisional-radiative models with a large amount of accurate atomic data.General agreement is obtained between the results of experiment and computation.Most of the lines in the spectra are identified,and the relative number density ratios orB,C,O and Fe are determined.It is found that the processes of line formation in our experiment are similar to those in the stellar coronae.The line-averaged electron density of the tokamak plasma is measured by the HCN laser,indicating a good agreement with the theoretical prediction by the density-dependent line ratio of Fe XXI.

  2. Zooming into the broad line region of the gravitationally lensed quasar Q2237+0305 = the Einstein Cross: III. Determination of the size and structure of the CIV and CIII] emitting regions using microlensing

    CERN Document Server

    Sluse, D; Courbin, F; Hutsemékers, D; Meylan, G; Eigenbrod, A; Anguita, T; Agol, E; Wambsganss, J

    2010-01-01

    Aims: We aim to use microlensing taking place in the lensed quasar Q2237+0305 to study the structure of the broad line region and measure the size of the region emitting the CIV and CIII] lines. Methods: Based on 39 spectrophotometric monitoring data points obtained between Oct. 2004 and Dec. 2007, we derive lightcurves for the CIV and CIII] emission lines. We use three different techniques to analyse the microlensing signal. Different components of the lines (narrow, broad and very broad) are identified and studied. We build a library of simulated microlensing lightcurves which reproduce the signal observed in the continuum and in the lines provided only the source size is changed. A Bayesian analysis scheme is then developed to derive the size of the various components of the BLR. Results: 1. The half-light radius of the region emitting the CIV line is found to be R_CIV ~ 66^{+110}_{-46} lt-days = 0.06^{+0.09}_{-0.04} pc = 1.7^{+2.8}_{-1.1} 10^17 cm (at 68.3% CI). Similar values are obtained for CIII]. Rela...

  3. TIGER/Line Shapefile, 2013, county, Iron County, UT, Current Address Ranges Relationship File

    Data.gov (United States)

    US Census Bureau, Department of Commerce — The TIGER/Line shapefiles and related database files (.dbf) are an extract of selected geographic and cartographic information from the U.S. Census Bureau's Master...

  4. Unresolved dielectronic satellites of the resonance line of heliumlike iron (Fe XXV)

    International Nuclear Information System (INIS)

    (1s2nl - 1s2pnl, n greater than or equal to 3) dielectronic satellites of the resonance line of Fe XXV at 1.85 A have been observed from PLT (Princeton Large Torus) tokamak discharges and are used for a detailed comparison with theory. The necessary corrections for Doppler broadening measurements are discussed, and accurate satellite to resonance line ratios allowing for a determination of the total dielectronic recombination rate of Fe XXV are derived

  5. Variability of factors that affect availability of iron, manganese and zinc in maize lines

    OpenAIRE

    Dragičević Vesna; Mladenović-Drinić Snežana; Stojiljković Milovan; Filipović Milomir; Dumanović Zoran; Kovačević Dragan

    2013-01-01

    Deficiencies of some mineral elements are causing serious health problems, which could be prevented by increase of mineral nutrients in food with supplementation, food fortification or plant breeding. From this point, experiment with 78 maize inbred lines was set up to determine maize lines with improved contents of Fe, Zn and Mn, as well as their relations with phytic acid, inorganic phosphorus and β-carotene, as factors which affect their absorption. Obta...

  6. AN EXTREME GRAVITATIONALLY REDSHIFTED IRON LINE AT 4.8 KeV IN Mrk 876

    Energy Technology Data Exchange (ETDEWEB)

    Bottacini, Eugenio; Orlando, Elena; Moskalenko, Igor [W. W. Hansen Experimental Physics Laboratory and Kavli Institute for Particle Astrophysics and Cosmology, Stanford University (United States); Greiner, Jochen [Max-Planck-Institut für extraterrestrische Physik, Giessenbachstrasse 1, D-85748 Garching (Germany); Ajello, Marco [Department of Physics and Astronomy, Clemson University, Clemson, SC 29634-0978 (United States); Persic, Massimo, E-mail: eugenio.bottacini@stanford.edu [INAF-Trieste, via G.B.Tiepolo 11, I-34143 Trieste (Italy)

    2015-01-01

    X-ray spectral lines at unforeseen energies are important because they can shed light on the extreme physical conditions of the environment around the supermassive black holes of active galactic nuclei (AGNs). Mrk 876 displays such a line at 4.80{sub −0.04}{sup +0.05} rest-frame energy. A possible interpretation of its origin can be found in the hotspot scenario. In this scenario, the primary radiation from a flare in the hot corona of an AGN illuminates a limited portion of the accretion disk that emits by fluorescence. In this context, the line can represent an extreme gravitationally redshifted Fe line originating on the accretion disk below six gravitational radii from a rotating supermassive black hole. The correct estimate of the line significance requires a dedicated approach. Based on an existing rigorous approach, we have performed extensive Monte Carlo simulations. We determine that the line is a real feature at a ∼99% confidence level.

  7. X-ray bumps, iron K-alpha lines, and X-ray suppression by obscuring tori in Seyfert galaxies

    Science.gov (United States)

    Krolik, Julian H.; Madau, Piero; Zycki, Piotr T.

    1994-01-01

    We investigate the X-ray spectral properties of unobscured type 1 and obscured type 2 Seyferts as predicted by the unified Seyfert scheme. We consider the reprocessing of X-ray photons by photoelectric absorption, iron fluorescence, and Compton downscattering in the obscuring tori surrounding these active nuclei, and compute by Monte Carlo methods the reprocessed spectra as a function of the viewing angle. Depending on the optical depth and shape of the torus, and on the viewing angle, the X-ray flux can be suppressed by substantial factors when our line of sight is obscured. We show that an immediate consequence of the existence of an obscuring thick torus is the production in the spectra of type 1 Seyfert galaxies of a bump in the continuum above 10-20 keV and an Fe K-alpha line with significant equivalent width. In those type 2 Seyferts for which the hard X-ray spectrum has been substantially suppressed, the equivalent width of the Fe K-alpha line in the transmitted spectrum can be very large.

  8. Red Supergiant Stars as Cosmic Abundance Probes: NLTE Effects in J-band Iron and Titanium Lines

    CERN Document Server

    Bergemann, Maria; Plez, Bertrand; Davies, Ben; Lind, Karin; Gazak, Zach

    2012-01-01

    Detailed non-LTE calculations for red supergiant stars are presented to investigate the influence of NLTE on the formation of atomic iron and titanium lines in the J-band. With their enormous brightness at J-band red supergiant stars are ideal probes of cosmic abundances. Recent LTE studies have found that metallicities accurate to 0.15 dex can be determined from medium resolution spectroscopy of individual red supergiants in galaxies as distant as 10 Mpc. The non-LTE results obtained in this investigation support these findings. Non-LTE abundance corrections for iron are smaller than 0.05 dex for effective temperatures between 3400K to 4200K and 0.1 dex at 4400K. For titanium the non-LTE abundance corrections vary smoothly between -0.4 dex and +0.2 dex as a function of effective temperature. For both elements, the corrections also depend on stellar gravity and metallicity. The physical reasons behind the non-LTE corrections and the consequences for extragalactic J-band abundance studies are discussed.

  9. RED SUPERGIANT STARS AS COSMIC ABUNDANCE PROBES: NLTE EFFECTS IN J-BAND IRON AND TITANIUM LINES

    International Nuclear Information System (INIS)

    Detailed non-LTE (NLTE) calculations for red supergiant (RSG) stars are presented to investigate the influence of NLTE on the formation of atomic iron and titanium lines in the J band. With their enormous brightness at J band RSG stars are ideal probes of cosmic abundances. Recent LTE studies have found that metallicities accurate to 0.15 dex can be determined from medium-resolution spectroscopy of individual RSGs in galaxies as distant as 10 Mpc. The NLTE results obtained in this investigation support these findings. NLTE abundance corrections for iron are smaller than 0.05 dex for effective temperatures between 3400 K and 4200 K and 0.1 dex at 4400 K. For titanium the NLTE abundance corrections vary smoothly between –0.4 dex and +0.2 dex as a function of effective temperature. For both elements, the corrections also depend on stellar gravity and metallicity. The physical reasons behind the NLTE corrections and the consequences for extragalactic J-band abundance studies are discussed.

  10. Degradation of organic dye using zero-valent iron prepared from by-product of pickling line.

    Science.gov (United States)

    Jung, S C; Cho, H C; Ra, D G; Park, S H; Yoon, H S; Kim, S C; Kim, S J

    2011-01-01

    In this study, zero-valent iron (ZVI) was produced using iron oxide that is a by-product of a pickling line at a steel works. The reaction activity of the produced ZVI was evaluated through a series of decomposition experiments of Orange II aqueous solution. The size of ZVI particles increased with reduction temperature due to coalescence. Correspondingly, the specific surface area of ZVI decreased with increasing reduction temperature. The decomposition efficiency of synthesized ZVI particles was higher at a lower pH. In particular, no significant decomposition reaction was observed at pH of 4 and higher. The rate of the ZVI-assisted decomposition of Orange II was increased by addition of H2O2 at pH of 3, whereas it was reduced by addition of H2O2 at a higher pH of 6. Nevertheless, simultaneous use of ZVI, UV and H2O2 led to a considerable increase in the decomposition rate even at a high pH condition (pH = 6). PMID:22097085

  11. A comparative study of SG-HMXBS and SFXTS using iron K-alpha line as a tracer

    Science.gov (United States)

    Pradhan, Pragati; Paul, Biswajit; Bozzo, Enrico

    2016-07-01

    We present a comparative study of classical supergiant HMXB and SFXT systems by making a detailed study of the variation of the equivalent width of iron k-alpha line with the absorption column density using out-of-eclipse observations from Suzaku, XMM, and Chandra (and taking care not to mix observations in different spectral states). Analysis of the entire archival Suzaku observations of these systems show that the equivalent width of SFXTs is significantly smaller compared to those of classical supergiant HMXBs even when the hydrogen column density of both are comparable. We discuss the results of the analysis in the light of two theories on SFXTS: the clumpy wind and the magnetic gating model. The findings are also used to make a comparison between these two systems as a class.

  12. Spectral study of GX 339-4 with TCAF: Signature of Double-Peaked Iron Line

    CERN Document Server

    Mondal, Santanu; Debnath, Dipak

    2016-01-01

    We fit the spectra of the galactic transient source GX~339-4 during its 2013 outburst using Two Component Advective Flow (TCAF) solution. The data is from the recent NuSTAR observation. The residual clearly fits with a double peaked Fe $K_{\\alpha}$ line which is indicative of a rapidly rotating matter close to a black hole. We used LAOR model for fitting the Fe $K_{\\alpha}$ line. From the TCAF model fitted flow parameters, we conclude that the source was in the hard state throughout this particular outburst. Our computation indicates that the Kerr parameter is near extreme and is around $a\\sim 0.989$.

  13. On the lack of X-ray iron line reverberation in MCG-6-30-15 Implications for the black hole mass and accretion disk structure

    CERN Document Server

    Reynolds, C S

    1999-01-01

    We use the method of Press, Rybicki & Hewitt (1992) to search for time lags and time leads between different energy bands of the RXTE data for MCG-6-30-15. We tailor our search in order to probe any reverberation signatures of the fluorescent iron Kalpha line that is thought to arise from the inner regions of the black hole accretion disk. In essence, an optimal reconstruction algorithm is applied to the continuum band (2-4keV) light curve which smoothes out noise and interpolates across the data gaps. The reconstructed continuum band light curve can then be folded through trial transfer functions in an attempt to find lags or leads between the continuum band and the iron line band (5-7keV). We find reduced fractional variability in the line band. The spectral analysis of Lee et al. (1999) reveals this to be due to a combination of an apparently constant iron line flux (at least on timescales of few x 10^4s), and flux correlated changes in the photon index. We also find no evidence for iron line reverbera...

  14. Zooming into the broad line region of the gravitationally lensed quasar QSO 2237 + 0305 ≡ the Einstein Cross. III. Determination of the size and structure of the C iv and C iii] emitting regions using microlensing

    Science.gov (United States)

    Sluse, D.; Schmidt, R.; Courbin, F.; Hutsemékers, D.; Meylan, G.; Eigenbrod, A.; Anguita, T.; Agol, E.; Wambsganss, J.

    2011-04-01

    Aims: We aim to use microlensing taking place in the lensed quasar QSO 2237 + 0305 to study the structure of the broad line region (BLR) and measure the size of the region emitting the C iv and C iii] lines. Methods: Based on 39 spectrophotometric monitoring data points obtained between Oct. 2004 and Dec. 2007, we derived lightcurves for the C iv and C iii] emission lines. We used three different techniques to analyse the microlensing signal. Different components of the lines (narrow, broad, and very broad) were identified and studied. We built a library of the simulated microlensing lightcurves that reproduce the signal observed in the continuum and in the lines provided only the source size is changed. A Bayesian analysis scheme is then developed to derive the size of the various components of the BLR. Results: 1. The half-light radius of the region emitting the C iv line is found to be RC IV} ˜ 66+110-46} light-days = 0.06+0.09-0.04 pc = 1.7+2.8-1.1 × 1017 cm (at 68.3% CI). Similar values are obtained for C iii]. Relative sizes of the carbon-line and V-band continuum emitting-regions are also derived with median values of Rline/Rcont in the range 4 to 29, depending on the FWHM of the line component. 2. The size of the C iv emitting region agrees with the radius-luminosity relationship derived from reverberation mapping. Using the virial theorem, we derive the mass of the black hole in QSO 2237 + 0305 to be MBH ~ 108.3 ± 0.3 M⊙. 3. We find that the C iv and C iii] lines are produced in at least 2 spatially distinct regions, the most compact one giving rise to the broadest component of the line. The broad and narrow line profiles are slightly different for C iv and C iii]. 4. Our analysis suggests a different structure for the C iv and Fe ii+iii emitting regions, with the latter produced in the inner part of the BLR or in a less extended emitting region than C iv. Based on observations made with the ESO-VLT Unit Telescope # 2 Kueyen (Cerro Paranal, Chile

  15. Spectroscopic Diagnostics of Solar Magnetic Flux Ropes Using Iron Forbidden Line

    CERN Document Server

    Cheng, X

    2016-01-01

    In this Letter, we present Interface Region Imaging Spectrograph Fe XXI 1354.08 A forbidden line emission of two magnetic flux ropes (MFRs) that caused two fast coronal mass ejections with velocities of $\\ge$1000 km s$^{-1}$ and strong flares (X1.6 and M6.5) on 2014 September 10 and 2015 June 22, respectively. The EUV images at the 131 A and 94 A passbands provided by the Atmospheric Imaging Assembly on board Solar Dynamics Observatory reveal that both MFRs initially appear as suspended hot channel-like structures. Interestingly, part of the MFRs is also visible in the Fe XXI 1354.08 forbidden line, even prior to the eruption, e.g., for the SOL2014-09-10 event. However, the line emission is very weak and that only appears at a few locations but not the whole structure of the MFRs. This implies that the MFRs could be comprised of different threads with different temperatures and densities, based on the fact that the formation of the Fe XXI forbidden line requires a critical temperature ($\\sim$11.5 MK) and dens...

  16. Discovery of a broad O VIII Ly alpha line in the ultra-compact X-ray binary 4U 1543-624

    OpenAIRE

    Madej, O.K.; Jonker, P. G

    2010-01-01

    We report the discovery of a broad emission feature at ~0.7 keV in the spectra of the ultra-compact X-ray binary 4U 1543-624, obtained with the high-resolution spectrographs of the XMM-Newton and Chandra satellites. We confirm the presence of the feature in the broad band MOS2 spectrum of the source. As suggested before in the literature, the donor star in this source is a CO or ONe white dwarf, which transfers oxygen-rich material to the accretor, conceivably a neutron star. The X-rays repro...

  17. Departure of high temperature iron lines from the equilibrium state in flaring solar plasmas

    CERN Document Server

    Kawate, Tomoko; Jess, David B

    2016-01-01

    The aim of this study is to clarify if the assumption of ionization equilibrium and a Maxwellian electron energy distribution is valid in flaring solar plasmas. We analyze the 2014 December 20 X1.8 flare, in which the \\ion{Fe}{xxi} 187~\\AA, \\ion{Fe}{xxii} 253~\\AA, \\ion{Fe}{xxiii} 263~\\AA\\ and \\ion{Fe}{xxiv} 255~\\AA\\ emission lines were simultaneously observed by the EUV Imaging Spectrometer onboard the Hinode satellite. Intensity ratios among these high temperature Fe lines are compared and departures from isothermal conditions and ionization equilibrium examined. Temperatures derived from intensity ratios involving these four lines show significant discrepancies at the flare footpoints in the impulsive phase, and at the looptop in the gradual phase. Among these, the temperature derived from the \\ion{Fe}{xxii}/\\ion{Fe}{xxiv} intensity ratio is the lowest, which cannot be explained if we assume a Maxwellian electron distribution and ionization equilibrium, even in the case of a multi-thermal structure. This re...

  18. XMM-Newton observation of the Seyfert 1.8 ESO 113-G010: discovery of a highly redshifted iron line at 5.4 keV

    CERN Document Server

    Porquet, D; Uttley, P; Turner, T J

    2004-01-01

    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 Kalpha 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. (2004). Alternatively, the emission from a narrow annulus at the surface of the accretion disk.

  19. Atomic Decay Data for Modeling K Lines of Iron Peak and Light Odd-Z Elements*

    Science.gov (United States)

    Palmeri, P.; Quinet, P.; Mendoza, C.; Bautista, M. A.; Garcia, J.; Witthoeft, M. C.; Kallman, T. R.

    2012-01-01

    Complete data sets of level energies, transition wavelengths, A-values, radiative and Auger widths and fluorescence yields for K-vacancy levels of the F, Na, P, Cl, K, Sc, Ti, V, Cr, Mn, Co, Cu and Zn isonuclear sequences have been computed by a Hartree-Fock method that includes relativistic corrections as implemented in Cowan's atomic structure computer suite. The atomic parameters for more than 3 million fine-structure K lines have been determined. Ions with electron number N greater than 9 are treated for the first time, and detailed comparisons with available measurements and theoretical data for ions with N less than or equal to 9 are carried out in order to estimate reliable accuracy ratings.

  20. A one-dimensional Chandrasekhar-mass delayed-detonation model for the broad-lined Type Ia supernova 2002bo

    CERN Document Server

    Blondin, Stéphane; Hillier, D John

    2015-01-01

    We present 1D non-local thermodynamic equilibrium (non-LTE) time-dependent radiative-transfer simulations of a Chandrasekhar-mass delayed-detonation model which synthesizes 0.51 Msun of 56Ni, and confront our results to the Type Ia supernova (SN Ia) 2002bo over the first 100 days of its evolution. Assuming only homologous expansion, this same model reproduces the bolometric and multi-band light curves, the secondary near-infrared (NIR) maxima, and the optical and NIR spectra. The chemical stratification of our model qualitatively agrees with previous inferences by Stehle et al., but reveals significant quantitative differences for both iron-group and intermediate-mass elements. We show that +/-0.1 Msun (i.e., +/-20 per cent) variations in 56Ni mass have a modest impact on the bolometric and colour evolution of our model. One notable exception is the U-band, where a larger abundance of iron-group elements results in less opaque ejecta through ionization effects, our model with more 56Ni displaying a higher nea...

  1. Leveraging High Resolution Spectra to Understand the Disk and Relativistic Iron Line of Cygnus X-1

    Science.gov (United States)

    Nowak, M.; Wilms, J.; Pottschmidt, K.; Grinberg, V.; Schulz, N.; Corrales, L.

    2016-06-01

    In April 2008 we conducted an observation of the black hole candidate Cygnus X-1 that was performed simultaneously with every X-ray and gamma-ray satellite flying at that time, including Chandra-HETG. The HETG spectra are crucial for modeling the ionized absorbtion from the "focused-wind" of the secondary, which is present and must be accounted for in all of our spectra. These features, however, are unresolved in the non-gratings instruments (e.g., RXTE, Suzaku, Swift, XMM-EPIC, INTEGRAL). Similarly, we must account for differences in spatial resolution. The X-ray scattering dust halo, which is usually ignored in most analyses, is spatially resolved in the Chandra and XMM-Newton spectra, but is unresolved in the other instruments. Thus one must account for dust scattering loss in the high spatial resolution spectra, and the scattering back into our line of site for the low resolution spectra. In this work, we attempt to arrive at a joint model for these spectra, and further comment on the cross calibration of each of the X-ray instruments participating in this campaign.

  2. Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. I - An 8 month campaign of monitoring NGC 5548 with IUE

    Science.gov (United States)

    Clavel, J.; Wamsteker, W. A.; Reichert, G. A.; Crenshaw, D. M.; Alloin, D.

    1991-01-01

    Emission-line and UV continuum observations of the type I Seyfert galaxy NGC 5548 were carried out for a period of 8 months with the IUE satellite. It was found that both the continuum shape and the line ratios of NGC 5548, while being not unusual for type I Seyfert galaxies, are strongly variable. The UV continuum flux and broad emission line fluxed went through three large maxima and three deep minima; the ratio of miximum to minimum flux was about 4.5 for the continuum at 1350 A. The N V and the He II emission lines exhibited maximum-to-minimum flux ratios as high as those of the continuum; other ionization lines (Ly-alpha, C IV, and C III) exhibited smaller amplitude fluctuations, with the smallest being recorded for the Mg II line (about 1.3). It was found that, except for Mg II, the emission-line variations correlated extremely well with those of the 1350-A continuum.

  3. Discovery of a broad iron line in the black hole candidate Swift J1753.5-0127, and the disc emission in the low/hard state revisited

    NARCIS (Netherlands)

    Hiemstra, Beike; Soleri, Paolo; Mendez, Mariano; Belloni, Tomaso; Mostafa, Reham; Wijnands, Rudy

    2009-01-01

    We analysed simultaneous archival XMM-Newton and Rossi X-ray Timing Explorer observations of the X-ray binary and black hole candidate Swift J1753.5-0127. In a previous analysis of the same data, a soft thermal component was found in the X-ray spectrum, and the presence of an accretion disc extendin

  4. Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. II - An intensive study of NGC 5548 at optical wavelengths

    Science.gov (United States)

    Peterson, B. M.; Balonek, T. J.; Barker, E. S.; Bechtold, J.; Bertram, R.

    1991-01-01

    A large, international program of ground-based optical spectroscopy and photometry of the variable Seyfert 1 galaxy NGC 5548 undertaken in support of an IUE monitoring campaign is described. This contribution presents the data base and describes the methods used to correct for systematic differences between spectra from different sources. Optical continuum and H-beta emission-line light curves are derived from the spectra. The behavior of the optical continuum is qualitatively the same as the behavior of the ultraviolet continuum. Cross-correlation of the ultraviolet and optical continuum measurements does not reveal any significant lag between them. The h-beta emission-line variations show the same basic pattern as seen in the continuum and ultraviolet emission lines, with H-beta lagging behind the continuum by about 20 days. This is significantly larger than the about 10 day lag deduced for Ly-alpha.

  5. Investigation of iron emission lines in the eclipsing high mass X-ray binary pulsar OAO 1657-415

    CERN Document Server

    Jaisawal, Gaurava K

    2016-01-01

    We present the results obtained from timing and spectral studies of high mass X-ray binary pulsar OAO 1657-415 using a Suzaku observations in 2011 September. X-ray pulsations were detected in the light curves up to $\\sim$70 keV. The continuum spectra during the high- and low-flux regions in light curves were well described by high energy cutoff power-law model along with a blackbody component and iron fluorescent lines at 6.4 keV and 7.06 keV. Time resolved spectroscopy was carried out by dividing the entire observations into 18 narrow segments. Presence of additional dense matter at various orbital phases was confirmed as the cause of low-flux regions in the observations. Presence of additional matter at several orbital phases of the pulsar was interpreted as due to the inhomogeneously distributed clumps of matter around the neutron star. Using clumpy wind hypothesis, the physical parameters of the clumps causing the high- and low-flux episodes in the pulsar light curve were estimated. The equivalent width o...

  6. Constraining possible variations of the fine structure constant in strong gravitational fields with the Kα iron line

    International Nuclear Information System (INIS)

    In extensions of general relativity and in theories aiming at unifying gravity with the forces of the Standard Model, the value of the ''fundamental constants'' is often determined by the vacuum expectation value of new fields, which may thus change in different backgrounds. Variations of fundamental constants with respect to the values measured today in laboratories on Earth are expected to be more evident on cosmological timescales and/or in strong gravitational fields. In this paper, I show that the analysis of the Kα iron line observed in the X-ray spectrum of black holes can potentially be used to probe the fine structure constant α in gravitational potentials relative to Earth of Δφ ≈ 0.1. At present, systematic effects not fully under control prevent to get robust and stringent bounds on possible variations of the value of α with this technique, but the fact that current data can be fitted with models based on standard physics already rules out variations of the fine structure constant larger than some percent

  7. XMM-Newton observation of the Seyfert 1.8 ESO 113-G010: Discovery of a highly redshifted iron line at 5.4 keV

    Science.gov (United States)

    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 ironline. 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.

  8. Missing Fe: hydrogenated iron nanoparticles

    CERN Document Server

    Bilalbegovic, G; Mohacek-Grosev, V

    2016-01-01

    Although it was found that the FeH lines exist in the spectra of some stars, none of the spectral features in the ISM have been assigned to this molecule. We suggest that iron atoms interact with hydrogen and produce Fe-H nanoparticles which sometimes contain many H atoms. We calculate infrared spectra of hydrogenated iron nanoparticles using density functional theory methods and find broad, overlapping bands. Desorption of H2 could induce spinning of these small Fe-H dust grains. Some of hydrogenated iron nanoparticles posses magnetic and electric moments and should interact with electromagnetic fields in the ISM. Fe_nH_m nanoparticles could contribute to the polarization of the ISM and the anomalous microwave emission. We discuss the conditions required to form FeH and Fe_nH_m in the ISM.

  9. On-line iron loss resistance identification by a state observer for rotor-flux-oriented control of induction motor

    Energy Technology Data Exchange (ETDEWEB)

    Barrera, Pablo M. de la; Bossio, Guillermo R.; Garcia, Guillermo O. [Grupo de Electronica Aplicada (GEA), Facultad de Ingenieria, UNRC, Ruta Nacional 36 Km. 601, X5804BYA, Rio Cuarto (Argentina); Solsona, Jorge A. [Instituto de Investigaciones en Ingenieria Electrica ' ' Alfredo Desages' ' , Departamento de Ingenieria Electrica y de Computadoras, UNS, Av. Alem 1253 (8000) Bahia Blanca (Argentina)

    2008-10-15

    A rotor flux state observer considering iron loss, for an Induction Motor (IM), is proposed. The aim of this proposal is to avoid detuning caused by the IM iron loss on a field-oriented control (FOC). An adaptive scheme for the K{sub Fe}, a parameter that represents the IM iron loss, is also proposed. The main objective of this scheme is to improve the dynamic response of control by compensating the variations of iron losses due to possible variations in the stator core characteristics. Simulation results demonstrated that the observer and the adaptive scheme showed a good performance fulfilling then the objectives. (author)

  10. Steps Toward Determination of the Size and Structure of the Broad-Line Region in Active Galactic Nuclei XVI: A 13 Year Study of Spectral Variability in NGC 5548

    Science.gov (United States)

    Peterson, B. M.; Berlind, P.; Bertram, R.; Bischoff, K.; Bochkarev, N. G.; Burenkov, A. N.; Calkins, M.; Carrasco, L.; Chavushyan, V. H.

    2002-01-01

    We present the final installment of an intensive 13 year study of variations of the optical continuum and broad H beta emission line in the Seyfert 1 galaxy NGC 5548. The database consists of 1530 optical continuum measurements and 1248 H beta measurements. The H beta variations follow the continuum variations closely, with a typical time delay of about 20 days. However, a year-by-year analysis shows that the magnitude of emission-line time delay is correlated with the mean continuum flux. We argue that the data are consistent with the simple model prediction between the size of the broad-line region and the ionizing luminosity, r is proportional to L(sup 1/2)(sub ion). Moreover, the apparently linear nature of the correlation between the H beta response time and the nonstellar optical continuum F(sub opt) arises as a consequence of the changing shape of the continuum as it varies, specifically F(sub opt) is proportional to F(sup 0.56)(sub UV).

  11. A Coherent Study of Emission Lines from Broad-Band Photometry: Specific Star-Formation Rates and [OIII]/H{\\beta} Ratio at 3 < z < 6

    CERN Document Server

    Faisst, A L; Hsieh, B C; Laigle, C; Salvato, M; Tasca, L; Cassata, P; Davidzon, I; Ilbert, O; Fevre, O Le; Masters, D; McCracken, H J; Steinhardt, C; Silverman, J D; De Barros, S; Hasinger, G; Scoville, N Z

    2016-01-01

    We measure the H{\\alpha} and [OIII] emission line properties as well as specific star-formation rates (sSFR) of spectroscopically confirmed 33 cannot be fully explained in a picture of cold accretion driven growth. We find a progressively increasing [OIII]{\\lambda}5007/H{\\beta} ratio out to z~6, consistent with the ratios in local galaxies selected by increasing H{\\alpha} EW (i.e., sSFR). This demonstrates the potential of using "local high-z analogs" to investigate the spectroscopic properties and relations of galaxies in the re-ionization epoch.

  12. Short-Timescale monitoring of the X-ray, UV and broad double-peak emission line of the nucleus of NGC 1097

    CERN Document Server

    Schimoia, Jaderson S; Grupe, Dirk; Eracleous, Michael; Peterson, Bradley M; Baldwin, Jack A; Nemmen, Rodrigo S; Winge, Cláudia

    2014-01-01

    Recent studies have suggested that the short-timescale ($\\lesssim7$ days) variability of the broad ($\\sim$10,000 km s$^{-1}$) double-peaked H$\\alpha$ profile of the LINER nucleus of NGC1097 could be driven by a variable X-ray emission from a central radiatively inefficient accretion flow (RIAF). To test this scenario, we have monitored the NGC1097 nucleus in X-ray and UV continuum with Swift and the H$\\alpha$ flux and profile in the optical spectrum using SOAR and Gemini-South from 2012 August to 2013 February. During the monitoring campaign, the H$\\alpha$ flux remained at a very low level --- 3 times lower than the maximum flux observed in previous campaigns and showing only limited ($\\sim 20\\%$) variability. The X-ray variations were small, only $\\sim 13\\%$ throughout the campaign, while the UV did not show significant variations. We concluded that the timescale of the H$\\alpha$ profile variation is close to the sampling interval of the optical observations, which results in only marginal correlation betwee...

  13. Iron isotope systematics of the Skaergaard intrusion

    DEFF Research Database (Denmark)

    Lesher, Charles; Lundstrom, C.C.; Barfod, Gry;

    crystallization on non-traditional stable isotope systems, particularly iron. FeTi oxide minerals (titanomagnetite and ilmenite) appear after ~60% of the magma had solidified. This was a significant event affecting the liquid line of descent and potentially accompanied by iron isotope fractionation. Here we...... report the results of a broad study of the iron isotope compositions of gabbros within the layered and upper border series of the Skaergaard intrusion, pegmatite and granophyre associated with these gabbroic rocks, and the sandwich horizon thought to represent the product of extreme differentiation and....../or liquid immiscibility. Forty-eight whole rock samples from well-constrained stratigraphic levels in the intrusion were crushed, powdered and dissolved, followed by iron separation by ion chromatography. Purified solutions were analyzed by MC- ICPMS in high-resolution mode using the sample-std bracket...

  14. Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. 6: Variability of NGC 3783 from ground-based data

    Science.gov (United States)

    Stirpe, G. M.; Winge, C.; Altieri, B.; Alloin, D.; Aguero, E. L.; Anupama, G. C.; Ashley, R.; Bertram, R.; Calderon, J. H.; Catchpole, R. M.

    1994-01-01

    The Seyfert 1 galaxy NGC 3783 was intensely monitored in several bands between 1991 December and 1992 August. This paper presents the results from the ground-based observations in the optical and near-IR bands, which complement the data set formed by the International Ultraviolet Explorer (IUE) spectra, discussed elsewhere. Spectroscopic and photometric data from several observatories were combined in order to obtain well-sampled light curves of the continuum and of H(beta). During the campaign the source underwent significant variability. The light curves of the optical continuum and of H(beta) display strong similarities to those obtained with the IUE. The near-IR flux did not vary significantly except for a slight increase at the end of the campaign. The cross-correlation analysis shows that the variations of the optical continuum have a lag of 1 day or less with respect to those of the UV continuum, with an uncertainty of is less than or equal to 4 days. The integrated flux of H(beta) varies with a delay of about 8 days. These results confirm that (1) the continuum variations occur simultaneously or with a very small lag across the entire UV-optical range, as in the Seyfert galaxy NGC 5548; and (2) the emission lines of NGC 3783 respond to ionizing continuum variations with less delay than those of NGC 5548. As observed in NGC 5548, the lag of H(beta) with respect to the continuum is greater than those of the high-ionization lines.

  15. Does ascorbate in the mesophyll cell walls form the first line of defence against ozone? Testing the concept using broad bean (Vicia faba L.).

    Science.gov (United States)

    Turcsányi, E; Lyons, T; Plöchl, M; Barnes, J

    2000-05-01

    Broad bean (Vicia faba L.) plants were exposed, in duplicate controlled environment chambers, to charcoal/Purafil-filtered air (CFA-grown plants) or to 75 nmol mol(-1) ozone (O(3)) for 7 h d(-1) (O(3)-grown plants) for 28 d, and then exposed to 150 nmol mol(-1) O(3 )for 8 h. The concentration of ascorbate (ASC) was determined in leaf extracellular washing fluid (apoplast) and in the residual leaf tissue (symplast) after 0, 4 and 8 h acute fumigation, and after a 16 h "recovery" period in CFA. Changes in stomatal conductance were measured in vivo in order to model pollutant uptake, while the light-saturated rate of CO(2) assimilation (A:(sat)) was recorded as an indicator of O(3)-induced intracellular damage. Measurements of A:(sat) revealed enhanced tolerance to 150 nmol mol(-1) O(3) in plants pre-exposed to the pollutant compared with equivalent plants grown in CFA, consistent with the observed reduction in pollutant uptake due to lower stomatal conductance. The concentration of ASC in the leaf apoplast (ASC(apo)) declined upon O(3)-treatment in both CFA- and O(3)-grown plants, consistent with the oxidation of ASC(apo) under O(3)-stress. Furthermore, the decline in ASC(apo) was reversible in O(3)-grown plants after a 16 h "recovery" period, but not in plants grown in CFA. No significant change in the level and/or redox state of ASC in the symplast (ASC(symp)) was observed in plants exposed to 150 nmol mol(-1) O(3), and there was no difference in the constitutive level of ASC(symp) between CFA- and O(3)-grown plants. Model calculations indicated that the reaction of O(3) with ASC(apo) in the leaves of Vicia faba is potentially sufficient to intercept a substantial proportion (30-40%) of the O(3)entering the plant under environmentally-relevant conditions. The potential role of apoplastic ASC in mediating the tolerance of leaves to O(3) is discussed.

  16. Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. IV - Intensity variations of the optical emission lines of NGC 5548

    Science.gov (United States)

    Dietrich, M.; Kollatschny, W.; Peterson, B. M.; Bechtold, J.; Bertram, R.; Bochkarev, N. G.; Boroson, T. A.; Carone, T. E.; Elvis, M.; Filippenko, A. V.

    1993-01-01

    Measurements of optical emission-line flux variations based on spectra of the Seyfert galaxy NGC 5548 obtained between December 1988 and October 1989 are reported. All of the measured optical emission lines, H-alpha, H-beta, H-gamma, He I 5876, and He II 4686, exhibit the same qualitative behavior as the UV and optical continua, but with short time delays, or lags, which are different for the various lines. Cross-correlation analysis is applied to measure the lags between the various lines and the continuum. Similar lags are found with respect to the UV continuum for H-alpha and H-beta, 17 and 19 d, respectively. The lag for H-gamma is shorter (13 d), only somewhat larger than the lag measured for Ly-alpha (about 10 d). The helium lines respond to continuum variations more rapidly than the hydrogen lines, with lags of about 7 d for He II 4686 and 11 d for He I 5876.

  17. Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. 8: An intensive HST, IUE, and ground-based study of NGC 5548

    Science.gov (United States)

    Korista, K.; Alloin, D.; Barr, P.; Clavel, J.; Cohen, R. D.; Crenshaw, D. M.; Evans, I. N.; Horne, K.; Koratkar, A. P.; Kriss, G. A.

    1994-01-01

    We present the data and initial results from a combined HST/IUE/ground-based spectroscopic monitoring campaign on the Seyfert 1 galaxy NGC 5548 that was undertaken in order to address questions that require both higher temporal resolution and higher signal-to-noise ratios than were obtained in our previous multiwavelength monitoring of this galaxy in 1988-89. IUE spectra were obtained once every two days for a period of 74 days beginning on 14 March 1993. During the last 39 days of this campaign, spectroscopic observations were also made with the HST Faint Object Spectrograph (FOS) on a daily basis. Ground-based observations, consisting of 165 optical spectra and 77 photometric observations (both CCD imaging and aperture photometry), are reported for the period 1992 October to 1993 September, although much of the data are concentrated around the time of the satellite-based program. These data constitute a fifth year of intensive optical monitoring of this galaxy. In this contribution, we describe the acquisition and reduction of all of the satellite and ground-based data obtained in this program. We describe in detail various photometric problems with the FOS and explain how we identified and corrected for various anomalies. During the HST portion of the monitoring campaign, the 1350 A continuum flux is found to have varied by nearly a factor of two. In other wavebands, the continuum shows nearly identical behavior, except that the amplitude of variability is larger at shorter wavelengths, and the continuum light curves appear to show more short time-scale variability at shorter wavelengths. The broad emission lines also vary in flux, with amplitudes that are slightly smaller than the UV continuum variations and with a small time delay relative to the UV continuum. On the basis of simple time-series analysis of the UV and optical continuum and emission line light curves, we find (1) that the ultraviolet and optical continuum variations are virtually simultaneous

  18. Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. 5: Variability of the ultraviolet continuum and emission lines of NGC 3783

    Science.gov (United States)

    Reichert, G. A.; Rodriguez-Pascual, P. M.; Alloin, D.; Clavel, J.; Crenshaw, D. M.; Kriss, G. A.; Krolik, J. H.; Malkan, M. A.; Netzer, H.; Peterson, B. M.

    1994-01-01

    We report on the results of intensive ultraviolet spectral monitoring of the Seyfert 1 galaxy NGC 3783. The nucleus of NGC 3783 was observed with the International Ultraviolet Explorer satellite on a regular basis for a total of 7 months, once every 4 days for the first 172 days and once every other day for the final 50 days. Significant variability was observed in both continuum and emission-line fluxes. The light curves for the continuum fluxes exhibited two well-defined local minima or 'dips,' the first lasting is less than or approximately 20 days and the second is less than or approximately 4 days, with additional episodes of relatively rapid flickering of approximately the same amplitude. As in the case of NGC 5548 (the only other Seyfert galaxy that has been the subject of such an intensive, sustained monitoring effort), the largest continuum variations were seen at the shortest wavelengths, so that the continuum became 'harder' when brighter. The variations in the continuum occurred simultaneously at all wavelengths (delta(t) is less than 2 days). Generally, the amplitude of variability of the emission lines was lower than (or comparable to) that of the continuum. Apart from Mg II (which varied little) and N V (which is relatively weak and badly blended with Ly(alpha), the light curves of the emission lines are very similar to the continuum light curves, in each case with a small systematic delay or 'lag.' As for NGC 5548, the highest ionization lines seem to respond with shorter lags than the lower ionization lines. The lags found for NGC 3783 are considerably shorter than those obtained for NGC 5548, with values of (formally) approximately 0 days for He II + O III), and approximately 4 days for Ly(alpha) and C IV. The data further suggest lags of approximately 4 days for Si IV + O IV) and 8-30 days for Si III + C III). Mg II lagged the 1460 A continuum by approximately 9 days, although this result depends on the method of measuring the line flux and may

  19. LINES

    Directory of Open Access Journals (Sweden)

    Minas Bakalchev

    2015-10-01

    Full Text Available The perception of elements in a system often creates their interdependence, interconditionality, and suppression. The lines from a basic geometrical element have become the model of a reductive world based on isolation according to certain criteria such as function, structure, and social organization. Their traces are experienced in the contemporary world as fragments or ruins of a system of domination of an assumed hierarchical unity. How can one release oneself from such dependence or determinism? How can the lines become less “systematic” and forms more autonomous, and less reductive? How is a form released from modernistic determinism on the new controversial ground? How can these elements or forms of representation become forms of action in the present complex world? In this paper, the meaning of lines through the ideas of Le Corbusier, Leonidov, Picasso, and Hitchcock is presented. Spatial research was made through a series of examples arising from the projects of the architectural studio “Residential Transformations”, which was a backbone for mapping the possibilities ranging from playfulness to exactness, as tactics of transformation in the different contexts of the contemporary world.

  20. Iron and Iron Metabolism

    OpenAIRE

    Melike Sezgin Evim; Birol Baytan; Adalet Meral Güneş

    2012-01-01

    Iron is an essential element for almost all living organisms except some bacteria. A great number of new articles related to the iron metabolism have been published in recent years explaining new findings. Hepsidine, a peptide hormon, that is recently found, regulates iron methabolism by effecting iron absorbsion from gut, secreting iron from hepatic store and flows iron from macrophages. Hepsidin blockes to effluxe iron from cells by bounding to ferroportin and by inducing ferroportin destru...

  1. SIX YEARS OF FERMI-LAT AND MULTI-WAVELENGTH MONITORING OF THE BROAD-LINE RADIO GALAXY 3C 120: JET DISSIPATION AT SUB-PARSEC SCALES FROM THE CENTRAL ENGINE

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Y. T. [Hiroshima Astrophysical Science Center, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526 (Japan); Doi, A.; Inoue, Y.; Stawarz, L. [Institute of Space and Astronautical Science, JAXA, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan); Cheung, C. C. [Space Science Division, Naval Research Laboratory, Washington, DC 20375-5352 (United States); Fukazawa, Y.; Itoh, R. [Department of Physical Sciences, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Gurwell, M. A. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Tahara, M.; Kataoka, J., E-mail: ytanaka@hep01.hepl.hiroshima-u.ac.jp [Research Institute for Science and Engineering, Waseda University, Tokyo 169-8555 (Japan)

    2015-01-30

    We present multi-wavelength monitoring results for the broad-line radio galaxy 3C 120 in the MeV/GeV, sub-millimeter, and 43 GHz bands over 6 yr. Over the past 2 yr, the Fermi-Large Area Telescope sporadically detected 3C 120 with high significance and the 230 GHz data also suggest an enhanced activity of the source. After the MeV/GeV detection from 3C 120 in MJD 56240–56300, 43 GHz Very Long Baseline Array (VLBA) monitoring revealed a brightening of the radio core, followed by the ejection of a superluminal knot. Since we observed the γ-ray and VLBA phenomena in temporal proximity to each other, it is naturally assumed that they are physically connected. This assumption was further supported by the subsequent observation that the 43 GHz core brightened again after a γ-ray flare occurred around MJD 56560. We can then infer that the MeV/GeV emission took place inside an unresolved 43 GHz core of 3C 120 and that the jet dissipation occurred at sub-parsec distances from the central black hole (BH), if we take the distance of the 43 GHz core from the central BH as ∼0.5 pc, as previously estimated from the time lag between X-ray dips and knot ejections. Based on our constraints on the relative locations of the emission regions and energetic arguments, we conclude that the γ rays are more favorably produced via the synchrotron self-Compton process, rather than inverse Compton scattering of external photons coming from the broad line region or hot dusty torus. We also derived the electron distribution and magnetic field by modeling the simultaneous broadband spectrum.

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

    Science.gov (United States)

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

    2016-10-01

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

  3. The Seyfert 2 galaxy NGC 2110: hard X-ray emission observed by NuSTAR and variability of the ironline

    DEFF Research Database (Denmark)

    Marinucci, A.; Matt, G.; Bianchi, S.;

    2015-01-01

    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, Suz...... linearly correlated with the source flux (possibly arising from Compton-thin material much closer to the black hole)....... found and, by using temporal information collected over more than a decade, we investigate variations of the ironline 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...

  4. Redox speciation analysis of dissolved iron in estuarine and coastal waters with on-line solid phase extraction and graphite furnace atomic absorption spectrometry detection.

    Science.gov (United States)

    Chen, Yaojin; Feng, Sichao; Huang, Yongming; Yuan, Dongxing

    2015-05-01

    An automatic on-line solid phase extraction (SPE) system employing the flow injection (FI) technique directly coupled to a graphite furnace atomic absorption spectrometer (GFAAS) was established for speciation and determination of dissolved iron in estuarine and coastal waters. Fe(II) was mixed with ferrozine solution in a sample stream to form the Fe(II)-ferrozine complex which was extracted onto a C18 SPE cartridge, eluted with eluent and detected with GFAAS. In a parallel flow channel, Fe(III) was reduced to Fe(II) with ascorbic acid and then detected in the same way as Fe(II). The home-made interface between FI-SPE and GFAAS efficiently realized the sample introduction to the furnace in a semi-automated way. Parameters of the FI-SPE system and graphite furnace program were optimized based on a univariate experimental design and an orthogonal array design. The salinity effect on the method sensitivity was investigated. The proposed method provided a detection limit of 1.38 nmol L(-1) for Fe(II) and 1.87 nmol L(-1) for Fe(II+III). With variation of the sample loading volume, a broadened determination range of 2.5-200 nmol L(-1) iron could be obtained. The proposed method was successfully applied to analyze iron species in samples collected from the Jiulongjiang Estuary, Fujian, China. With the 2-cartridge FI-SPE system developed, on-line simultaneous determination of Fe species with GFAAS was achieved for the first time. PMID:25770602

  5. On the importance of satellite lines to the He-like alpha complex and the G ration for calcium, iron, and nickel

    Energy Technology Data Exchange (ETDEWEB)

    Oelgoetz, Justin R [Los Alamos National Laboratory; Fontes, Christopher J [Los Alamos National Laboratory; Zhang, Hong L [Los Alamos National Laboratory; Nahar, Sultana N [OHIO STATE UNIV; Pradhan, Anil K [OHIO STATE UNIV

    2008-01-01

    New, more detailed calculations of the emission spectra of the He-like Ko complex of calcium, iron and nickel have been carried out using data from both distorted-wave and R-matrix calculations. The value of the GD ratio (a corrected version of the G ratio that accounts for the effect of unresolved satellite lines) is significantly enhanced at temperatures below the temperature of He-like maximum abundance. Furthermore it is shown that satellite lines are important contributors to the G D ratio at temperatures well above the temperature of maximum abundance. These new calculations demonstrate that satellite lines need to be included in models of He-like Ko spectra even at relatively high temperatures. The excellent agreement between spectra and line ratios calculated from R-matrix and distorted-wave data also confirms the validity of models based on distorted-wave data for highly charged systems, provided the effect of resonances are taken into account as independent processes.

  6. Road and Street Centerlines, State Line, Published in 2007, 1:24000 (1in=2000ft) scale, Iron County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — , published at 1:24000 (1in=2000ft) scale, was produced all or in part from Other information as of 2007. It is described as 'State Line'. The extent of these data...

  7. Scale heights and equivalent widths of the iron K-shell lines in the Galactic diffuse X-ray emission

    CERN Document Server

    Yamauchi, Shigeo; Nobukawa, Masayoshi; Uchiyama, Hideki; Koyama, Katsuji

    2016-01-01

    This paper reports the analysis of the X-ray spectra of the Galactic diffuse X-ray emission (GDXE) in the Suzaku archive. The fluxes of the Fe I K alpha (6.4 keV), Fe XXV,He alpha (6.7 keV) and Fe XXVI Ly alpha (6.97 keV) lines are separately determined. From the latitude distributions, we confirm that the GDXE is decomposed into the Galactic center (GCXE), the Galactic bulge (GBXE) and the Galactic ridge (GRXE) X-ray emissions. The scale heights (SHs) of the Fe XXV He alpha line of the GCXE, GBXE and GRXE are determined to be ~40, ~310 and ~140 pc, while those of the Fe I K alpha line are ~30, ~160 and ~70 pc, respectively. The mean equivalent widths (EWs) of the sum of the Fe XXV He alpha and Fe XXVI Ly alpha lines are ~750 eV, ~600 eV and ~550 eV, while those of the Fe I K alpha line are ~150~eV, ~60~eV and ~100~eV for the GCXE, GBXE and GRXE, respectively. The origin of the GBXE, GRXE and GCXE is separately discussed based on the new results of the SHs and EWs, in comparison with those of the Cataclysmic ...

  8. Kinetic equilibrium of iron in the atmospheres of cool dwarf stars II. Weak Fe I lines in the solar spectrum

    CERN Document Server

    Gehren, T; Shi, J

    2001-01-01

    NLTE line formation calculations of FeI in the solar atmosphere are extended to include weak optical lines. Previously established atomic models are used to discriminate between different ways of treating collisional interaction processes. To derive a common solar FeI abundance from both strong and weak lines, fine-tuning of the microturbulence velocity parameter and the van-der- Waals damping constants is required. The solar FeI abundances based on all available f-values are dominated by the large scatter already found for the stronger lines. In particular the bulk of the data from the work of May et al. and O'Brian et al. is not adequate for accurate abundance work. Based on f-values measured by the Hannover and Oxford groups alone, the FeI LTE abundances are eps(FeI,Sun)=7.57 for the empirical and eps(FeI,Sun) = 7.48 ... 7.51 for the line-blanketed solar model. The solar Fe ionization equilibrium obtained for different atomic and atmospheric models rules out NLTE atomic models with a low efficiency of hydr...

  9. The 2010 Broad Prize

    Science.gov (United States)

    Education Digest: Essential Readings Condensed for Quick Review, 2011

    2011-01-01

    A new data analysis, based on data collected as part of The Broad Prize process, provides insights into which large urban school districts in the United States are doing the best job of educating traditionally disadvantaged groups: African-American, Hispanics, and low-income students. Since 2002, The Eli and Edythe Broad Foundation has awarded The…

  10. Iron Features in the XMM-Newton spectrum of NGC 4151

    CERN Document Server

    Schurch, N J; Griffiths, R E; Ptak, A F

    2002-01-01

    We present a detailed analysis of the hard X-ray (>2.5 keV) EPIC spectra from the first observations of NGC 4151 made by XMM-Newton. We fit the spectra with a model consisting of a power-law continuum modified by line-of-sight absorption (arising in both partially photoionized and neutral gas) plus additional iron-K emission and absorption features. This model provides an excellent overall fit to the EPIC spectra. The iron K-alpha line is well modelled as a narrow Gaussian component. In contrast to several earlier studies based on data from ASCA, a relativistically broadened iron K-alpha emission feature is not required by the XMM-Newton data. The upper limit on the flux contained in any additional broad line is ~8% of that in the narrow line. The measured intrinsic line width (sigma =32+_7 eV) may be ascribed to (i) the doublet nature of the iron K-alpha line and (ii) emission from low ionization states of iron, ranging from neutral up to ~FeXVII. The additional iron absorption edge arises in cool material a...

  11. The hydro- and multi-isotope geochemistry of iron-rich ground waters emerging at the southern Baltic Sea coast line

    Science.gov (United States)

    Lipka, Marko; Wu, Zijun; Escher, Peter; Struck, Ulrich; Dellwig, Olaf; Schafmeister, Maria; Böttcher*, Michael E.

    2013-04-01

    preferentially desorbed from the aqueous solution. The changes in the stream composition lead to the formation of iron(oxyhyr)oxide precipitates in the stream bed before the waters pass to underground drainage into a subterranean mixing zone with brackish BS waters. These ochrous precipitates act as a sink for dissolved phosphate and minor calcium. P : Fe ratios and Ca : Fe ratios are about 0.08 and 0.2, respectively, which are caused by P adsorption and a mixture with minor CaCO3 and/or Ca-phosphate. The investigation reveals that the surface precipitation on the beach leads to the formation of SGD essentially free of dissolved iron and strongly depleted in phosphate. Similar iron phases may also be an important part of the subterranean estuary supposed at that coast line, where retention of nutrients and heavy metals by iron(oxyhydr)oxides could influence the release of nutrients into the coastal ecosystem. Fe- and P-rich surface precipitates, however, are transported in suspension into the Baltic Sea during wind-driven flood events. Acknowledgements: This work was partly supported by the BONUS+ project AMBER and the Leibniz IOW.

  12. Implementation of an iron ore green pellet on-line size analyser at the QCMC pelletizing plant

    Energy Technology Data Exchange (ETDEWEB)

    Bouajila, A.; Boivin, J.-A. [Centre de recherche minerale due Quebec (CRM), Quebec, PQ (Canada); Ouellet, G.; Beaudin, S. [Quebec Cartier Mining Company (QCMC), Quebec, PQ (Canada)

    1999-07-01

    This paper describes work into the design, implementation and performance evaluation of a 3D-image analysis system at the QCMC pelletizing plant. First, the measurement system is reviewed. Second, the ability of the system to achieve reliable, on-line results on a moving conveyor belt is presented and discussed. The problem of segregation caused by disk classification is particularly addressed, as it hinders full size distribution estimation from the top layer. Finally, pelletizing disk controllability is investigated. (author)

  13. Iron-line and continuum variations in the XMM-Newton and Suzaku spectra of the neutron-star low-mass X-ray binary 4U 1636-53

    NARCIS (Netherlands)

    Lyu, Ming; Mendez, Mariano; Belloni, Tomaso; Homan, Jeroen; Sanna, Andrea; Hiemstra, Beike

    2014-01-01

    We used six simultaneous XMM-Newton and Rossi X-ray Timing Explorer plus five Suzaku observations to study the continuum spectrum and the iron emission line in the neutron-star low-mass X-ray binary 4U 1636-53 as a function of the position of the source in the colour-colour diagram. We modelled the

  14. State of the iron

    DEFF Research Database (Denmark)

    Reinisch, Walter; Staun, Michael; Bhandari, Sunil;

    2013-01-01

    Iron deficiency anemia (IDA) frequently occurs in patients suffering from inflammatory bowel disease (IBD) and negatively impacts their quality of life. Nevertheless, the condition appears to be both under-diagnosed and undertreated. Regular biochemical screening of patients with IBD for anemia...... by the gastroenterology community has to be advocated. Oral iron is a low cost treatment however its effectiveness is limited by low bioavailability and poor tolerability. Intravenous (IV) iron rapidly replenishes iron stores and has demonstrated its safe use in a number of studies in various therapeutic areas. A broad...... spectrum of new IV iron formulations is now becoming available offering improved tolerability and patient convenience by rapidly restoring the depleted iron status of patients with IBD. The following article aims to review the magnitude of the problem of IDA in IBD, suggest screening standards...

  15. Iron-line and continuum variations in the XMM-Newton and Suzaku spectra of the neutron-star low-mass X-ray binary 4U 1636-53

    CERN Document Server

    Lyu, Ming; Sanna, Andrea; Homan, Jeroen; Belloni, Tomaso; Hiemstra, Beike

    2014-01-01

    We used six simultaneous XMM-Newton and Rossi X-ray Timing Explorer plus five Suzaku observations to study the continuum spectrum and the iron emission line in the neutron-star low-mass X-ray binary 4U 1636-53. We modelled the spectra with two thermal components (representing the accretion disc and boundary layer), a Comptonised component (representing a hot corona), and either a Gaussian or a relativistic line component to model an iron emission line at about 6.5 keV. For the relativistic line component we used either the diskline, laor or kyrline model, the latter for three different values of the spin parameter. The fitting results for the continuum are consistent with the standard truncated disc scenario. We also find that the flux and equivalent width of the iron line first increase and then decrease as the flux of the Comptonised component increases. This could be explained either by changes in the ionisation state of the accretion disc where the line is produced by reflection, or by light bending of th...

  16. Fourier evaluation of broad Moessbauer spectra

    International Nuclear Information System (INIS)

    It is shown by the Fourier analysis of broad Moessbauer spectra that the even part of the distribution of the dominant hyperfine interaction (hyperfine field or quadrupole splitting) can be obtained directly without using least-square fitting procedures. Also the odd part of this distribution correlated with other hyperfine parameters (e.g. isomer shift) can be directly determined. Examples for amorphous magnetic and paramagnetic iron-based alloys are presented. (author)

  17. Runs 800, 813, 842 and physics runs from 18.1.77 to 21.5.77, Development of a new set-up for working line measurements including a Fast Fourier Transform Spectrum Analyser and using weak beam excitiation with broad-band noise

    CERN Document Server

    Borer, J

    1977-01-01

    Runs 800, 813, 842 and physics runs from 18.1.77 to 21.5.77, Development of a new set-up for working line measurements including a Fast Fourier Transform Spectrum Analyser and using weak beam excitiation with broad-band noise

  18. Forbidden Iron Lines and Dust Destruction in Supernova Remnant Shocks: The Case of N49 in the Large Magellanic Cloud

    CERN Document Server

    Dopita, Michael A; Sutherland, Ralph S; Vogt, Frédéric P A; Winkler, P Frank; Blair, William P

    2016-01-01

    We present results of a complete integral field survey of the bright SNR N49 in the LMC, obtained with the WiFeS instrument mounted on the ANU 2.3m telescope at Siding Spring Observatory. From theoretical shock modelling with the new MAPPINGS 5.1 code we have, for the first time, subjected the optical Fe emission line spectrum of a supernova remnant to a detailed abundance and dynamical analysis covering 8 separate stages of ionisation. This allows us to derive the dust depletion factors as a function of ionisation stage. We have shown that there is substantial (30% - 90%) destruction of Fe-bearing dust grains in these fast shocks ($v_s \\sim 250$ km/s), and we have confirmed that the dominant dust destruction is through the non-thermal sputtering and grain-grain collision mechanisms developed in a number of theoretical works.

  19. Forbidden Iron Lines and Dust Destruction in Supernova Remnant Shocks: The Case of N49 in the Large Magellanic Cloud

    Science.gov (United States)

    Dopita, Michael A.; Seitenzahl, Ivo R.; Sutherland, Ralph S.; Vogt, Frédéric P. A.; Winkler, P. Frank; Blair, William P.

    2016-08-01

    We present the results of a complete integral-field survey of the bright supernova remnant (SNR) N49 in the Large Magellanic Cloud, obtained with the WiFeS instrument mounted on the ANU 2.3 m telescope at Siding Spring Observatory. From theoretical shock modeling with the new MAPPINGS 5.1 code, we have, for the first time, subjected the optical Fe emission line spectrum of an SNR to a detailed abundance and dynamical analysis covering eight separate stages of ionization. This allows us to derive the dust depletion factors as a function of ionization stage. We have shown that there is substantial (30%-90%) destruction of Fe-bearing dust grains in these fast shocks (v s ˜ 250 km s-1), and we have confirmed that the dominant dust destruction occurs through the non-thermal sputtering and grain-grain collision mechanisms developed in a number of theoretical works.

  20. Specific targeting of nasopharyngeal carcinoma cell line CNE1 by C225-conjugated ultrasmall superparamagnetic iron oxide particles with magnetic resonance imaging

    Institute of Scientific and Technical Information of China (English)

    Dongbo Lin; Chunli Chen; Guangyuaa Hu; Qi Mei; Hong Qiu; Guoxian Long; Guoqing Hu

    2011-01-01

    An accurate definition of clinical target volume (CTV) is essential for the application of radiotherapy in nasopharvngeai carcinoma (NPC) treatment. A novel epidermal growth factor receptor (EGFR)-targeting contrast agent (C225-USPIO) was designed by conjugating ultrasmail superparamagnetic iron oxide (USPIO) nanoparticles with cetuximab (C225), to non-invasively define the CTV of tumor. The immunobinding activity of C225-USPIO to NPC cell line CNEI was confirmed by flow cytometry and immunofluorescence. The time-dependent accumulation of C225-USPIO in CNE1 cells was evaluated using Prussian blue staining. Targeted internalization and subcellular localization of C225-USPIO was confirmed by transmission electron microscope. The results indicated that C225-USPIO specifically bound to EGFR on the surface of CNEI cells and was taken up into the cell. The uptake of C225-USPIO by CNE1 cells increased significantly with time, when compared with human IgG-USPIO. In addition, 4.7 T magnetic resonance imaging (MRI) revealed that C225-USPIO had a capacity to accumulate in the CNE1 cells, with a resultant marked decrease in MRI T2-weighted signal intensity over time. These findings imply that C225-USPIO has the potential as an MRI contrast agent and can be employed to non-invasively detect early-stage NPC with EGFR overexpression. This provides sufficient theoretical basis for commencing in vivo experiments with the compound.

  1. Iron and iron derived radicals

    Energy Technology Data Exchange (ETDEWEB)

    Borg, D.C.; Schaich, K.M.

    1987-04-01

    We have discussed some reactions of iron and iron-derived oxygen radicals that may be important in the production or treatment of tissue injury. Our conclusions challenge, to some extent, the usual lines of thought in this field of research. Insofar as they are born out by subsequent developments, the lessons they teach are two: Think fastexclamation Think smallexclamation In other words, think of the many fast reactions that can rapidly alter the production and fate of highly reactive intermediates, and when considering the impact of competitive reactions on such species, think how they affect the microenvironment (on the molecular scale) ''seen'' by each reactive molecule. 21 refs., 3 figs., 1 tab.

  2. Siderocalin/Lcn2/NGAL/24p3 does not drive apoptosis through gentisic acid mediated iron withdrawal in hematopoietic cell lines.

    Directory of Open Access Journals (Sweden)

    Colin Correnti

    Full Text Available Siderocalin (also lipocalin 2, NGAL or 24p3 binds iron as complexes with specific siderophores, which are low molecular weight, ferric ion-specific chelators. In innate immunity, siderocalin slows the growth of infecting bacteria by sequestering bacterial ferric siderophores. Siderocalin also binds simple catechols, which can serve as siderophores in the damaged urinary tract. Siderocalin has also been proposed to alter cellular iron trafficking, for instance, driving apoptosis through iron efflux via BOCT. An endogenous siderophore composed of gentisic acid (2,5-dihydroxybenzoic acid substituents was proposed to mediate cellular efflux. However, binding studies reported herein contradict the proposal that gentisic acid forms high-affinity ternary complexes with siderocalin and iron, or that gentisic acid can serve as an endogenous siderophore at neutral pH. We also demonstrate that siderocalin does not induce cellular iron efflux or stimulate apoptosis, questioning the role siderocalin plays in modulating iron metabolism.

  3. Broad band X-ray spectrum of KS 1947+300 with BeppoSAX

    CERN Document Server

    Naik, S; Dotani, T; Paul, B

    2006-01-01

    We present results obtained from three BeppoSAX observations of the accretion-powered transient X-ray pulsar KS 1947+300 carried out during the declining phase of its 2000 November -- 2001 June outburst. A detailed spectral study of KS 1947+300 across a wide X-ray band (0.1--100.0 keV) is attempted for the first time here. Timing analysis of the data clearly shows a 18.7 s pulsation in the X-ray light curves in the above energy band. The pulse profile of KS 1947+300 is characterized by a broad peak with sharp rise followed by a narrow dip. The dip in the pulse profile shows a very strong energy dependence. Broad-band pulse-phase-averaged spectroscopy obtained with three of the BeppoSAX instruments shows that the energy spectrum in the 0.1--100 keV energy band has three components, a Comptonized component, a ~0.6 keV blackbody component, and a narrow and weak iron emission line at 6.7 keV with a low column density of material in the line of sight. We place an upper limit on the equivalent width of the iron K_\\...

  4. Iron deficiency anaemia.

    Science.gov (United States)

    Lopez, Anthony; Cacoub, Patrice; Macdougall, Iain C; Peyrin-Biroulet, Laurent

    2016-02-27

    Anaemia affects roughly a third of the world's population; half the cases are due to iron deficiency. It is a major and global public health problem that affects maternal and child mortality, physical performance, and referral to health-care professionals. Children aged 0-5 years, women of childbearing age, and pregnant women are particularly at risk. Several chronic diseases are frequently associated with iron deficiency anaemia--notably chronic kidney disease, chronic heart failure, cancer, and inflammatory bowel disease. Measurement of serum ferritin, transferrin saturation, serum soluble transferrin receptors, and the serum soluble transferrin receptors-ferritin index are more accurate than classic red cell indices in the diagnosis of iron deficiency anaemia. In addition to the search for and treatment of the cause of iron deficiency, treatment strategies encompass prevention, including food fortification and iron supplementation. Oral iron is usually recommended as first-line therapy, but the most recent intravenous iron formulations, which have been available for nearly a decade, seem to replenish iron stores safely and effectively. Hepcidin has a key role in iron homoeostasis and could be a future diagnostic and therapeutic target. In this Seminar, we discuss the clinical presentation, epidemiology, pathophysiology, diagnosis, and acute management of iron deficiency anaemia, and outstanding research questions for treatment.

  5. [Iron deficiency and iron deficiency anemia are global health problems].

    Science.gov (United States)

    Dahlerup, Jens; Lindgren, Stefan; Moum, Björn

    2015-03-10

    Iron deficiency and iron deficiency anemia are global health problems leading to deterioration in patients' quality of life and more serious prognosis in patients with chronic diseases. The cause of iron deficiency and anemia is usually a combination of increased loss and decreased intestinal absorption and delivery from iron stores due to inflammation. Oral iron is first line treatment, but often hampered by intolerance. Intravenous iron is safe, and the preferred treatment in patients with chronic inflammation and bowel diseases. The goal of treatment is normalisation of hemoglobin concentration and recovery of iron stores. It is important to follow up treatment to ensure that these objectives are met and also long-term in patients with chronic iron loss and/or inflammation to avoid recurrence of anemia.

  6. Study of iron fluorination

    International Nuclear Information System (INIS)

    This report deals with the action of fluorine on iron. Comprehensive descriptions are given of the particular technological methods and of the preparation of the reactants. This fluorination reaction has been investigated over a very broad range of temperature and pressure. A nucleation and growth phenomenon is described. The influence of a pollution of the gas phase by oxygen on the fluorination process is reported. The solid-state reaction between ferric fluoride and iron has been studied by calorimetry and hydrated fluorides βFeF3, 3 H2O and FeF3, H2O have been studied by Moessbauer effect. A special study has been made of the growth of iron deposits by thermal decomposition of gaseous iron fluorides. (author)

  7. Intracellular iron minerals in a dissimilatory iron-reducing bacterium.

    Science.gov (United States)

    Glasauer, Susan; Langley, Sean; Beveridge, Terry J

    2002-01-01

    Among prokaryotes, there are few examples of controlled mineral formation; the formation of crystalline iron oxides and sulfides [magnetite (Fe3O4) or greigite (Fe3S4)] by magnetotactic bacteria is an exception. Shewanella putrefaciens CN32, a Gram-negative, facultative anaerobic bacterium that is capable of dissimilatory iron reduction, produced microscopic intracellular grains of iron oxide minerals during growth on two-line ferrihydrite in a hydrogen-argon atmosphere. The minerals, formed at iron concentrations found in the soil and sedimentary environments where these bacteria are active, could represent an unexplored pathway for the cycling of iron by bacteria. PMID:11778045

  8. Iron deficiency.

    Science.gov (United States)

    Scrimshaw, N S

    1991-10-01

    The world's leading nutritional problem is iron deficiency. 66% of children and women aged 15-44 years in developing countries have it. Further, 10-20% of women of childbearing age in developed countries are anemic. Iron deficiency is identified with often irreversible impairment of a child's learning ability. It is also associated with low capacity for adults to work which reduces productivity. In addition, it impairs the immune system which reduces the body's ability to fight infection. Iron deficiency also lowers the metabolic rate and the body temperature when exposed to cold. Hemoglobin contains nearly 73% of the body's iron. This iron is always being recycled as more red blood cells are made. The rest of the needed iron does important tasks for the body, such as binds to molecules that are reservoirs of oxygen for muscle cells. This iron comes from our diet, especially meat. Even though some plants, such as spinach, are high in iron, the body can only absorb 1.4-7% of the iron in plants whereas it can absorb 20% of the iron in red meat. In many developing countries, the common vegetarian diets contribute to high rates of iron deficiency. Parasitic diseases and abnormal uterine bleeding also promote iron deficiency. Iron therapy in anemic children can often, but not always, improve behavior and cognitive performance. Iron deficiency during pregnancy often contributes to maternal and perinatal mortality. Yet treatment, if given to a child in time, can lead to normal growth and hinder infections. However, excess iron can be damaging. Too much supplemental iron in a malnourished child promotes fatal infections since the excess iron is available for the pathogens use. Many countries do not have an effective system for diagnosing, treating, and preventing iron deficiency. Therefore a concerted international effort is needed to eliminate iron deficiency in the world.

  9. Magnetostructural study of iron sucrose

    International Nuclear Information System (INIS)

    Magnetic and structural analyses have been performed on an iron sucrose complex used as a haematinic agent. The system contains two-line ferrihydrite particles of about 5 nm that are superparamagnetic above approximately 50 K. The observed low-temperature magnetic dynamics of this compound is closer to simple models than in the case of other iron-containing drugs for intravenous use like iron dextran

  10. Clinical evaluation of serum ferritin to iron ratio in malignant diseases

    International Nuclear Information System (INIS)

    Serum ferritin levels were measured in 72 normal subjects and in 214 cases with various diseases by an immunoradiometric assay. In normal subjects, the serum ferritin levels were 27-230 ng/ml. Elevated serum ferritins were observed in most cases with iron excess and acute hepatitis. Markedly elevated levels were found in the majority of cases with acute leukemia, malignant lymphoma, hepatoma, and pancreatic cancer. High ferritin levels were also found in other malignant diseases. However, the range overlapped broadly with that of nonmalignant diseases. The serum ferritin correlated significantly with serum iron in normals and in those with iron deficiency anemia. In most nonmalignant cases, the serum ferritin and iron levels distributed on a regression line obtained from levels in normals and those with iron deficiency anemia. However, 92% of the malignant cases showed a serum ferritin to iron ratio higher than that of normal subjects. The estimation of the serum ferritin to iron ratio is a useful means for screening patients or in the differential diagnosis of a suspected malignant lesion. (orig.)

  11. Native iron

    DEFF Research Database (Denmark)

    Brooks, Charles Kent

    2015-01-01

    , a situation unique in the Solar System. In such a world, iron metal is unstable and, as we all know, oxidizes to the ferric iron compounds we call 'rust'. If we require iron metal it must be produced at high temperatures by reacting iron ore, usually a mixture of ferrous (Fe2+) and ferric (Fe3+) oxides (Fe2O3......, hematite, or FeO.Fe2O3, magnetite), with carbon in the form of coke. This is carried out in a blast furnace. Although the Earth's core consists of metallic iron, which may also be present in parts of the mantle, this is inaccessible to us, so we must make our own. In West Greenland, however, some almost...... unique examples of iron metal, otherwise called 'native iron' or 'telluric iron', occur naturally....

  12. CALCIUM CARBONATE REDUCES IRON ABSORPTION FROM IRON SULFATE, BUT NOT WHEN IRON IS PRESENTED AS AN ORGANIC COMPLEX

    Directory of Open Access Journals (Sweden)

    E. C. CONCEI�O

    2008-09-01

    Full Text Available

    line-height: normal; text-align: justify; mso-layout-grid-align: none;"> Experimental and epidemiological evidences have demonstrated that calcium inhibits iron absorption; calcium carbonate being one of the most effective calcium sources to reduce iron absorption from dietary origin or from iron sulfate. In the present work, the short-term effect of calcium from calcium carbonate on iron absorption was studied in rats, using different iron compounds (monosodium ferric EDTA, iron-bys-glicine, iron peptide complex with iron sulfate as a control. Eighty (80 animals were divided into groups of 10 animals each with homogeneous weight. After 18h fast, the animals received by gavage 5 mL of a dispersion containing one of the iron compounds (1mg Fe/kg body weight, concomitantly or not with calcium carbonate at a molar ratio of 150:1 (Ca/Fe. Two hours after the administration, the animals were sacrificed and blood was collected for serum iron determination (iron transfer rate from intestinal lumen to blood compartment. Additionally, the intestines were collected for soluble iron determination (available iron. The results demonstrated that calcium ion from calcium carbonate inhibits the iron absorption from iron sulfate, but not from organic iron (di- or trivalent complexes.

  13. Wet Chemistry of Spinel Iron oxide Particles

    OpenAIRE

    Jolivet, J.; Chanéac, C.; Prené, P.; Vayssières, L.; Tronc, E.

    1997-01-01

    Various properties of spinel iron oxide nanograins are reviewed, illustrating the broad possibilities of wet chemistry for tailoring materials for a wide range of utilizations, from catalysis and sensors to cast magnetic materials.

  14. Iron Abundance Diagnostics in High-Redshift QSOs

    CERN Document Server

    Corbin, M R; Freduling, N K W; Corbin, Michael R.; Korista, Kirk T.; Freduling, Nalaka Kodituwakku & Wolfram

    2004-01-01

    The abundance of alpha-process elements such as magnesium and carbon relative to iron measured from the broad emission lines of QSOs can serve as a diagnostic of the star formation and chemical enrichment histories of their host galaxies. We investigate the relationship between Fe/Mg and Fe/C abundance ratios and the resulting Fe II / Mg II 2800A and Fe II / 1900A-blend flux ratios, both of which have been measured in QSOs out to redshifts of approximately six. Using a galactic chemical evolution model based on a starburst in a giant elliptical galaxy, we find that these flux ratios are good tracers of the chemical enrichment of the nuclei. However, the values of these ratios measured in objects at redshifts of approximately six suggest that iron enrichment has occurred more rapidly in these objects than predicted by the assumed elliptical starburst model, under currently favored cosmologies.

  15. Integrating Hot and Cool Intelligences: Thinking Broadly about Broad Abilities

    Directory of Open Access Journals (Sweden)

    W. Joel Schneider

    2016-01-01

    Full Text Available Although results from factor-analytic studies of the broad, second-stratum abilities of human intelligence have been fairly consistent for decades, the list of broad abilities is far from complete, much less understood. We propose criteria by which the list of broad abilities could be amended and envision alternatives for how our understanding of the hot intelligences (abilities involving emotionally-salient information and cool intelligences (abilities involving perceptual processing and logical reasoning might be integrated into a coherent theoretical framework.

  16. Identifying the best iron-peak and $\\alpha$-capture elements for chemical tagging: The impact of the number of lines on measured scatter

    CERN Document Server

    Adibekyan, V; Santos, N C; Sousa, S G; Faria, J P; Delgado-Mena, E; Oshagh, M; Tsantaki, M; Hakobyan, A A; Hernandez, J I Gonzalez; Suarez-Andres, L; Israelian, G

    2015-01-01

    The main goal of this work is to explore which elements carry the most information about the birth origin of stars and as such that are best suited for chemical tagging. We explored different techniques to minimize the effect of outlier value lines in the abundances by using Ni abundances derived for 1111 FGK type stars.We evaluated how the limited number of spectral lines can affect the final chemical abundance. Then we were able to make an efficient even footing comparison of the [X/Fe] scatter between the elements that have different number of observable spectral lines in the studied spectra. We found that the most efficient way of calculating the average abundance of elements when several spectral lines are available is to use a weighted mean (WM) where as a weight we considered the distance from the median abundance. This method can be effectively used without removing suspected outlier lines.We showed that when the same number of lines is used to determine chemical abundances, the [X/Fe] star-to-star sc...

  17. Iron load

    Directory of Open Access Journals (Sweden)

    Filippo Cassarà

    2013-03-01

    Full Text Available Recent research addressed the main role of hepcidin in the regulation of iron metabolism. However, while this mechanism could be relevant in causing iron load in Thalassemia Intermedia and Sickle-Cell Anemia, its role in Thalassemia Major (TM is marginal. This is mainly due to the high impact of transfusional requirement into the severe increase of body iron. Moreover, the damage of iron load may be worsened by infections, as HCV hepatitis, or liver and endocrinological damage. One of the most relevant associations was found between splenectomy and increase of risk for mortality due,probably, to more severe iron load. These issues suggest as morbidity and mortality of this group of patients they do not depend only by our ability in controlling heart damage but even in preventing or treating particular infections and complications. This finding is supported by the impairment of survival curves in patients with complications different from heart damage. However, because, during recent years different direct and indirect methods to detect iron overload in patients affected by secondary hemochromatosis have been implemented, our ability to maintain under control iron load is significantly improved. Anyway, the future in iron load management remains to be able to have an iron load map of our body for targeting chelation and other medical treatment according to the single organ damage.

  18. Medicare Coverage Policies for Biologics: The Broad Gray Line

    OpenAIRE

    2008-01-01

    In October 2007, American Health & Drug Benefits asked Dr Joseph Antos to discuss the forces that have shaped Medicare's policies and their impact on the various stakeholders in US healthcare. The first part of the interview appeared in AHDB in February 2008. This second part focuses on the impact of the Centers for Medicare & Medicaid Services drug coverage on the future of biologic products. This discussion does not reflect any new developments occurring after October, such as the recent re...

  19. The broad line region in active galactic nuclei

    Directory of Open Access Journals (Sweden)

    D. Dultzin Hacyan

    2000-01-01

    Full Text Available Revisamos las limitaciones observacionales a los modelos sobre la estructura de las regiones que emiten las l neas anchas en los N ucleos Activos de Galaxias. La comparaci on entre las l neas de alta y baja ionizaci on con FWHM H 4000 km s

  20. On the determination of the solar iron abundance using Fe I lines. Comments on a paper by D.E. Blackwell et al. and presentation of new results for weak lines.

    Science.gov (United States)

    Holweger, H.; Kock, M.; Bard, A.

    1995-04-01

    We examine the critical remarks by Blackwell, Lynas-Gray & Smith (1995; A&A, this issue). Points discussed in detail include equivalent widths, oscillator strengths, microturbulence, damping, and models of the solar photosphere. In addition, we present new results based on the Fe i oscillator strengths of Bard & Kock (1994). The sample of weak solar lines, which are the most reliable abundance indicators, is greatly increased. The result is fully consistent with our earlier determinations based on lines of Fe i and Fe ii.

  1. The Broad Autism Phenotype Questionnaire

    Science.gov (United States)

    Hurley, Robert S. E.; Losh, Molly; Parlier, Morgan; Reznick, J. Steven; Piven, Joseph

    2007-01-01

    The broad autism phenotype (BAP) is a set of personality and language characteristics that reflect the phenotypic expression of the genetic liability to autism, in non-autistic relatives of autistic individuals. These characteristics are milder but qualitatively similar to the defining features of autism. A new instrument designed to measure the…

  2. Observations of the X-ray pulsar LMC X-4 with NuSTAR: limit on the magnetic field and tomography of the system in the fluorescent iron line

    CERN Document Server

    Shtykovsky, A E; Arefiev, V A; Molkov, S V; Tsygankov, S S

    2016-01-01

    We present results of the spectral and timing analysis of the X-ray pulsar LMC X-4 with the NuSTAR observatory in the broad energy range 3-79 keV. Along with the detailed analysis of the averaged source spectrum, the high-precision pulse phased-resolved spectra were obtained for the first time. It has been shown that the comptonization model gives the best approximation of the obtained spectra. The evolution of its parameters was traced depending on the pulse phase as well. The search for the possible cyclotron absorption line was performed for all energy spectra in the 5-55 keV energy range. The obtained upper limit for the depth of the cyclotron absorption line $\\tau\\simeq0.15$ ($3\\sigma$) indicates no cyclotron absorption line in this energy range, which provides an estimate of the magnitude of the magnetic field on the surface of the neutron star: $B 6.5 \\times 10^{12}$ G. The latter one is agree with the estimate of the magnetic field obtained from the analysis of the power spectrum of the pulsar: $B \\s...

  3. Hepcidin, a new iron regulatory peptide.

    Science.gov (United States)

    Nicolas, Gaël; Viatte, Lydie; Bennoun, Myriam; Beaumont, Carole; Kahn, Axel; Vaulont, Sophie

    2002-01-01

    Maintaining normal iron homeostasis is essential for the organism, as both iron deficiency and iron excess are associated with cellular dysfunction. Recently, several lines of evidence have suggested that hepcidin, a peptide mainly produced by the liver, plays a major role in the control of body iron homeostasis. The subject of this paper is to summarize the advances toward the understanding of function and regulation of hepcidin in iron metabolism and to provide new data on the regulation of hepcidin gene expression by erythropoietin, the major regulator of mammalian erythropoiesis. PMID:12547223

  4. 高压架空输电线路大跨越铁塔承台基础施工%On construction of crossing iron tower pier foundation of overhead ultra-high voltage power transmission lines

    Institute of Scientific and Technical Information of China (English)

    张俊平

    2011-01-01

    In the construction of the iron tower foundation power transmission lines,the paper indicates some features,including the weak geological conditions in the foundation,the tough tasks for the pier construction,and the long construction period,the paper introduces the difficulties and features of the crossing pier foundation construction of the power transmission lines,and adopts the effective measures in the cooling cycle water pipe,the temperature checking,and the surface maintenance of the concrete internal apparatus,and achieves satisfactory effects.%针对输电线路铁塔基础施工中,大量基础存在地质条件差、承台基础施工方量大、施工周期长等特点,详细介绍了输电线路大跨越大承台基础施工的难点、特点,在混凝土内部设置冷却循环水管及温度检测、表面养护等技术方面采取了有效的措施,并取得了满意的效果。

  5. The soft X-ray absorption lines of the Seyfert 1 galaxy MCG--6-30-15

    CERN Document Server

    Turner, A K; Lee, J C; Vaughan, S

    2004-01-01

    The absorption lines in the soft X-ray spectrum of MCG--6-30-15 are studied using the Reflection Grating Spectrometer data from the 2001 XMM-Newton 320 ks observation. A line search of the full time-averaged spectrum reveals 51 absorption lines and one emission line. The equivalent widths of the lines are measured and the majority of the lines identified. We find lines produced by a broad range of charge states for several elements, including almost all the charge states oxygen and iron, suggesting a broad range of ionization parameters is present in the warm absorber. The equivalent widths of the lines are broadly consistent with the best fitting warm absorber models from Turner et al (2003). The equivalent widths of the absorption lines allow confidence limits on the column density of the species to be determined. For OVII a column density of 10^18.36-10^18.86 cm^-2 is found. This column density of OVII, when combined with the inferred FeI absorption, is sufficient to explain the drop in flux at 0.7 keV as ...

  6. Broad Diphotons from Narrow States

    CERN Document Server

    An, Haipeng; Zhang, Yue

    2015-01-01

    ATLAS and CMS have each reported a modest diphoton excess consistent with the decay of a broad resonance at ~ 750 GeV. We show how this signal can arise in a weakly coupled theory comprised solely of narrow width particles. In particular, if the decaying particle is produced off-shell, then the associated diphoton resonance will have a broad, adjustable width. We present simplified models which explain the diphoton excess through the three-body decay of a scalar or fermion. Our minimal ultraviolet completion is a weakly coupled and renormalizable theory of a singlet scalar plus a heavy vector-like quark and lepton. The smoking gun of this mechanism is an asymmetric diphoton peak recoiling against missing transverse energy, jets, or leptons.

  7. Cochlear microphonic broad tuning curves

    Science.gov (United States)

    Ayat, Mohammad; Teal, Paul D.; Searchfield, Grant D.; Razali, Najwani

    2015-12-01

    It is known that the cochlear microphonic voltage exhibits much broader tuning than does the basilar membrane motion. The most commonly used explanation for this is that when an electrode is inserted at a particular point inside the scala media, the microphonic potentials of neighbouring hair cells have different phases, leading to cancelation at the electrodes location. In situ recording of functioning outer hair cells (OHCs) for investigating this hypothesis is exceptionally difficult. Therefore, to investigate the discrepancy between the tuning curves of the basilar membrane and those of the cochlear microphonic, and the effect of phase cancellation of adjacent hair cells on the broadness of the cochlear microphonic tuning curves, we use an electromechanical model of the cochlea to devise an experiment. We explore the effect of adjacent hair cells (i.e., longitudinal phase cancellation) on the broadness of the cochlear microphonic tuning curves in different locations. The results of the experiment indicate that active longitudinal coupling (i.e., coupling with active adjacent outer hair cells) only slightly changes the broadness of the CM tuning curves. The results also demonstrate that there is a π phase difference between the potentials produced by the hair bundle and the soma near the place associated with the characteristic frequency based on place-frequency maps (i.e., the best place). We suggest that the transversal phase cancellation (caused by the phase difference between the hair bundle and the soma) plays a far more important role than longitudinal phase cancellation in the broadness of the cochlear microphonic tuning curves. Moreover, by increasing the modelled longitudinal resistance resulting the cochlear microphonic curves exhibiting sharper tuning. The results of the simulations suggest that the passive network of the organ of Corti determines the phase difference between the hair bundle and soma, and hence determines the sharpness of the

  8. A non-LTE study of neutral and singly-ionized iron line spectra in 1D models of the Sun and selected late-type stars

    CERN Document Server

    Mashonkina, L; Shi, J -R; Korn, A J; Grupp, F

    2011-01-01

    A comprehensive model atom for Fe with more than 3000 energy levels is presented. As a test and first application of this model atom, Fe abundances are determined for the Sun and five stars with well determined stellar parameters and high-quality observed spectra. Non-LTE leads to systematically depleted total absorption in the Fe I lines and to positive abundance corrections in agreement with the previous studies, however, the magnitude of non-LTE effect is smaller compared to the earlier results. Non-LTE corrections do not exceed 0.1 dex for the solar metallicity and mildly metal-deficient stars, and they vary within 0.21 dex and 0.35 dex in the very metal-poor stars HD 84937 and HD 122563, respectively, depending on the assumed efficiency of collisions with hydrogen atoms. Based on the analysis of the Fe I/Fe II ionization equilibrium in these two stars, we recommend to apply the Drawin formalism in non-LTE studies of Fe with a scaling factor of 0.1. For the Fe II lines, non-LTE corrections do not exceed 0...

  9. Iron overdose

    Science.gov (United States)

    ... PA: Elsevier Saunders; 2014:chap 147. Liebelt EL. Iron. In: Shannon MW, Borron SW, Burns MJ, eds. Haddad and Winchester's Clinical Management of Poisoning and Drug Overdose . 4th ed. Philadelphia, PA: Elsevier ...

  10. Ghost imaging with broad distance

    Institute of Scientific and Technical Information of China (English)

    段德洋; 张路; 杜少将; 夏云杰

    2015-01-01

    We present a scheme that is able to achieve the ghost imaging with broad distance. The physical nature of our scheme is that the different wavelength beams are separated in free space by an optical media according to the slow light or dispersion principle. Meanwhile, the equality of the optical distance of the two light arms is not violated. The photon correlation is achieved by the rotating ground glass plate (RGGP) and spatial light modulator (SLM), respectively. Our work shows that a monochromic ghost image can be obtained in the case of RGGP. More importantly, the position (or distance) of the object can be ascertained by the color of the image. Thus, the imaging and ranging processes are combined as one process for the first time to the best of our knowledge. In the case of SLM, we can obtain a colored image regardless of where the object is.

  11. Iron and Your Child

    Science.gov (United States)

    ... Story" 5 Things to Know About Zika & Pregnancy Iron and Your Child KidsHealth > For Parents > Iron and ... enough iron in their daily diets. How Much Iron Do Kids Need? Kids require different amounts of ...

  12. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... have enough iron in your body. Low iron levels usually are due to blood loss, poor diet, ... iron supplements and multivitamins to improve her iron levels. Susan also made changes to her diet, such ...

  13. Iron deficiency

    DEFF Research Database (Denmark)

    Schou, Morten; Bosselmann, Helle; Gaborit, Freja;

    2015-01-01

    BACKGROUND: Both iron deficiency (ID) and cardiovascular biomarkers are associated with a poor outcome in heart failure (HF). The relationship between different cardiovascular biomarkers and ID is unknown, and the true prevalence of ID in an outpatient HF clinic is probably overlooked. OBJECTIVES.......043). CONCLUSION: ID is frequent in an outpatient HF clinic. ID is not associated with cardiovascular biomarkers after adjustment for traditional confounders. Inflammation, but not neurohormonal activation is associated with ID in systolic HF. Further studies are needed to understand iron metabolism in elderly HF...

  14. Relativistic Iron K Emission and absorption in the Seyfert 1.9 galaxy MCG-5-23-16

    CERN Document Server

    Braito, V; Dewangan, G C; George, I; Griffiths, R E; 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 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 K-alpha line. The time averaged spectral analysis shows that the iron K-shell complex is best modeled with an unresolved narrow emission component (FWHM < 5000 km/s, EW ~ 60 eV) plus a broad component. This latter component has FWHM ~ 44000 km/s and EW ~ 50 eV. Its profile is well described by an emission line originating from an accretion disk viewed with an inclination angle ~ 40^\\circ 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 EPIC-pn spectrum shows that both the narrow and broad components of the Fe K emission line appear to be constant in time within the errors. We detected a narrow sporadic absorption line at 7.7 keV which appears to be variable on a time-scale of 20 ksec. If associa...

  15. Ghost imaging with broad distance

    Science.gov (United States)

    Duan, De-Yang; Zhang, Lu; Du, Shao-Jiang; Xia, Yun-Jie

    2015-10-01

    We present a scheme that is able to achieve the ghost imaging with broad distance. The physical nature of our scheme is that the different wavelength beams are separated in free space by an optical media according to the slow light or dispersion principle. Meanwhile, the equality of the optical distance of the two light arms is not violated. The photon correlation is achieved by the rotating ground glass plate (RGGP) and spatial light modulator (SLM), respectively. Our work shows that a monochromic ghost image can be obtained in the case of RGGP. More importantly, the position (or distance) of the object can be ascertained by the color of the image. Thus, the imaging and ranging processes are combined as one process for the first time to the best of our knowledge. In the case of SLM, we can obtain a colored image regardless of where the object is. Project supported by the National Natural Science Foundation of China (Grant Nos. 61178012, 11204156, 11304179, and 11247240), the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant Nos. 20133705110001 and 20123705120002), the Scientific Research Foundation for Outstanding Young Scientists of Shandong Province, China (Grant No. BS2013DX034), and the Natural Science Foundation of Shandong Province, China (Grant No. ZR2012FQ024).

  16. Identification of the Broad Solar Emission Features Near 117 nm

    CERN Document Server

    Avrett, E H; Loeser, R; Avrett, Eugene H.; Kurucz, Robert L.; Loeser, Rudolf

    2006-01-01

    Wilhelm et al. have recently called attention to the unidentified broad emission features near 117 nm in the solar spectrum. They discuss the observed properties of these features in detail but do not identify the source of this emission. We show that the broad autoionizing transitions of neutral sulfur are responsible for these emission features. Autoionizing lines of \\ion{S}{i} occur throughout the spectrum between Lyman alpha and the Lyman limit. Sulfur is a normal contributor to stellar spectra. We use non-LTE chromospheric model calculations with line data from the Kurucz 2004 \\ion{S}{i} line list to simulate the solar spectrum in the range 116 to 118 nm. We compare the results with SUMER disk-center observations from Curdt et al. and limb observations from Wilhelm et al. Our calculations generally agree with the SUMER observations of the broad autoionizing \\ion{S}{i} emission features, the narrow \\ion{S}{i} emission lines, and the continuum in this wavelength region, and agree with basic characteristics...

  17. 78 FR 20119 - Broad Stakeholder Survey

    Science.gov (United States)

    2013-04-03

    ... SECURITY Broad Stakeholder Survey AGENCY: National Protection and Programs Directorate, DHS. ACTION: 30-day... soliciting comments concerning the Broad Stakeholder Survey. DHS previously published this ICR in the Federal... responders across the Nation. The Broad Stakeholder Survey is designed to gather stakeholder feedback on...

  18. 77 FR 50144 - Broad Stakeholder Survey

    Science.gov (United States)

    2012-08-20

    ... SECURITY Broad Stakeholder Survey AGENCY: National Protection and Programs Directorate, DHS. ACTION: 60-day... comments concerning the Broad Stakeholder Survey. DATES: Comments are encouraged and will be accepted until... across the Nation. The Broad Stakeholder Survey is designed to gather stakeholder feedback on...

  19. 76 FR 34087 - Broad Stakeholder Survey

    Science.gov (United States)

    2011-06-10

    ... SECURITY Broad Stakeholder Survey AGENCY: National Protection and Programs Directorate, DHS. ACTION: 60-day... comments concerning the Broad Stakeholder Survey. DATES: Comments are encouraged and will be accepted until.... The Broad Stakeholder Survey is designed to gather stakeholder feedback on the effectiveness of...

  20. Iron abundance in the atmosphere of Arcturus

    CERN Document Server

    Sheminova, V A

    2015-01-01

    Abundance of iron in the atmosphere of Arcturus has been determined from the profiles or regions of the profiles of the weak lines sensitive to iron abundance. The selected lines of Fe I and Fe II were synthesized with the MARCS theoretical models of the atmosphere. From the observed profiles of lines available with a high spectral resolution in the atlas by Hinkle and Wallace (2005), the values of the iron abundance $A = 6.95 \\pm 0.03$ and the radial-tangential macroturbulent velocity $5.6 \\pm 0.2$ km/s were obtained for Arcturus. The same physical quantities were found for the Sun as a star; they are $7.42 \\pm 0.02$ and $3.4 \\pm 0.3$ km/s, respectively. For Arcturus, the iron abundance relative to the solar one was determined with the differential method as [Fe/H] $=-0.48 \\pm 0.02$.

  1. Human iron transporters

    OpenAIRE

    Garrick, Michael D.

    2010-01-01

    Human iron transporters manage iron carefully because tissues need iron for critical functions, but too much iron increases the risk of reactive oxygen species. Iron acquisition occurs in the duodenum via divalent metal transporter (DMT1) and ferroportin. Iron trafficking depends largely on the transferrin cycle. Nevertheless, non-digestive tissues have a variety of other iron transporters that may render DMT1 modestly redundant, and DMT1 levels exceed those needed for the just-mentioned task...

  2. Colour Metallography of Cast Iron

    Institute of Scientific and Technical Information of China (English)

    By Zhou Jiyang; Professor

    2011-01-01

    5.5 Eutectic crystallisation of white iron When undercooled below the eutectic line ECF in the Fe-C phase diagram,liquid iron will start eutectic transformation (crystallization):eutectic liquid → cementite + austenite.Eutectic crystallisation is an important stage during the crystallization of white iron.At this stage,the nucleation and growth of eutectic cells (consisting of carbide or cementite + austenite) occur.The carbide in eutectic cells (or eutectic carbide) is the main hard and brittle phase structure which has an important effect on the properties of white iron.If there is no primary carbide in the structure,the effect of eutectic carbide is more prominent.5.5.1 Thermodynamics and kinetics of eutectic crystallisationWhether a eutectic melt follows the meta-stable system to crystallise as carbide + austenite,or follows the stable system to crystallise as graphite + austenite eutectic,is dependent on the nucleation and growth of the two high carbon phases (carbide and graphite),namely,on thermodynamic and kinetic conditions.Figure 5-23 shows the comparison of thermodynamic driving forces of the two eutectics.The two lines in the lower section of the figure represent the free energy of the two eutectics respectively and GL is the free energy of the undercooled iron melt.It is easy to see that the iron melt has the highest free energy and the graphiteaustenite has the lowest free energy;so,following a stable system,the thermodynamic condition favours the crystallisation of graphite-austenite eutectic from the iron melt.

  3. Iron bioavailability from commercially available iron supplements

    OpenAIRE

    Christides, Tatiana; Wray, David; McBride, Richard; Fairweather, Rose; Sharp, Paul

    2015-01-01

    Purpose Iron deficiency anaemia (IDA) is a global public health problem. Treatment with the standard of care ferrous iron salts may be poorly tolerated, leading to non-compliance and ineffective correction of IDA. Employing supplements with higher bioavailability might permit lower doses of iron to be used with fewer side effects, thus improving treatment efficacy. Here, we compared the iron bioavailability of ferrous sulphate tablets with alternative commercial iron products, including th...

  4. Selenium sorption and isotope fractionation: Iron(III) oxides versus iron(II) sulfides

    NARCIS (Netherlands)

    Mitchell, K.; Couture, R.-M.; Johnson, T.M.; Mason, P.R.D.; Van Cappellen, P.

    2013-01-01

    Sorption and reduction are important processes influencing the environmental mobility and cycling of Se. In this study, we determined the rates of reaction and isotopic fractionations of Se(IV) and Se(VI) during sorption to iron oxides (2-line ferrihydrite, hematite and goethite) and iron sulfides (

  5. Series of broad resonances in atomic three-body systems

    CERN Document Server

    Diaz, D; Hu, C -Y

    2016-01-01

    We re-examine the series of resonances found earlier in atomic three-body systems by solving the Faddeev-Merkuriev integral equations. These resonances are rather broad and line-up at each threshold with gradually increasing gaps, the same way for all thresholds and irrespective of the spatial symmetry. We relate these resonances to the Gailitis mechanism, which is a consequence of the polarization potential.

  6. Non haematological effects of iron deficiency - A perspective

    Directory of Open Access Journals (Sweden)

    Ghosh Kanjaksha

    2006-01-01

    Full Text Available Iron deficiency is a continuum beginning from lowering of tissue stores to the phase of exhausted tissue stores, interference with iron driven biochemical reactions in the body, microcytosis, hypochromia, increasing severity of anaemia with all its attendant consequences. Iron deficiency anaemia is a very well known concept but what is often not appreciated is the effect of broad canvas of iron deficiency on various tissues, organs and systems in our body in addition to iron deficiency anaemia leading to concept of "Iron deficiency disease". In this condition not only tissue delivery of oxygen is compromised but proliferation, growth, differentiation, myelinogenesis, immunofunction, energy metabolism, absorption and biotransformation are compromised leading to abnormal growth and behaviour, mental retardation, reduced cardiac performance and work efficiency, infection etc which ultimately leads to the concept that "iron deficiency not only breaks the machine but also wrecks the machinery."

  7. Ascorbate status modulates reticuloendothelial iron stores and response to deferasirox iron chelation in ascorbate-deficient rats

    DEFF Research Database (Denmark)

    Brewer, Casey; Otto-Duessel, Maya; Lykkesfeldt, Jens;

    2012-01-01

    Iron chelation is essential to patients on chronic blood transfusions to prevent toxicity from iron overload and remove excess iron. Deferasirox (DFX) is the most commonly used iron chelator in the United States; however, some patients are relatively refractory to DFX therapy. We postulated...... weeks. Cardiac and liver iron levels were measured after iron loading (n = 18), 12 weeks of sham chelation (n = 18), and 12 weeks of DFX chelation (n = 18) at 75 mg/kg/day. Ascorbate supplementation of 150 ppm, 900 ppm, and 2250 ppm was used in the chow to mimic a broad range of ascorbate status; plasma...... 12 weeks of sham chelation. Most importantly, ascorbate supplementation at 2250 ppm improved DFX efficiency, allowing DFX to remove 21% more hepatic iron than ascorbate supplementation with 900 ppm or 150 ppm (p

  8. Iron Sucrose Injection

    Science.gov (United States)

    Iron sucrose injection is used treat iron-deficiency anemia (a lower than normal number of red blood cells due ... may cause the kidneys to stop working). Iron sucrose injection is in a class of medications called ...

  9. Steam iron cleaner poisoning

    Science.gov (United States)

    ... cleaner is a substance used to clean steam irons. Poisoning occurs when someone swallows steam iron cleaner. This ... Below are symptoms of steam iron cleaner poisoning in different ... AND THROAT Severe pain in the throat Severe pain in the mouth ...

  10. Taking iron supplements

    Science.gov (United States)

    ... medlineplus.gov/ency/article/007478.htm Taking iron supplements To use the sharing features on this page, ... levels. You may also need to take iron supplements as well to rebuild iron stores in your ...

  11. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... refers to a condition in which your blood has a lower than normal number of red blood ... iron, your body starts using the iron it has stored. Soon, the stored iron gets used up. ...

  12. Formation depths of Fraunhofer lines

    CERN Document Server

    Gurtovenko, E A

    2015-01-01

    We have summed up our investigations performed in 1970--1993. The main task of this paper is clearly to show processes of formation of spectral lines as well as their distinction by validity and by location. For 503 photospheric lines of various chemical elements in the wavelength range 300--1000 nm we list in Table the average formation depths of the line depression and the line emission for the line centre and on the half-width of the line, the average formation depths of the continuum emission as well as the effective widths of the layer of the line depression formation. Dependence of average depths of line depression formation on excitation potential, equivalent widths, and central line depth are demonstrated by iron lines.

  13. First Constraints on Iron Abundance versus Reflection Fraction from the Seyfert$\\sim$1 Galaxy MCG-6-30-15

    CERN Document Server

    Lee, J C; Brandt, W N; Reynolds, C S; Iwasawa, K

    1999-01-01

    We report on a joint ASCA and RXTE observation spanning an $\\sim$ 400~ks time interval of the bright Seyfert~1 galaxy MCG--6-30-15. The data clearly confirm the presence of a broad skewed iron line ($W_{K\\alpha} \\sim$ 266 eV) and Compton reflection continuum at higher energies reported in our previous paper. We also investigate whether the gravitational and Doppler effects that affect the iron line may also be manifest in the reflected continuum. The uniqueness of this data set is underlined by the extremely good statistics that we obtain from the approximately four million photons that make up the 2-20 keV RXTE PCA spectrum alone. This, coupled with the high energy coverage of HEXTE and the spectral resolution of ASCA in the iron line regime has allowed us to constrain the relationship between abundance and reflection fraction for the first time at the 99 per cent confidence level. The reflection fraction is entirely consistent with a flat disk, i.e. the cold material subtends $\\rm 2 \\pi$ sr at the source, t...

  14. Genetics Home Reference: iron-refractory iron deficiency anemia

    Science.gov (United States)

    ... refractory iron deficiency anemia iron-refractory iron deficiency anemia Enable Javascript to view the expand/collapse boxes. ... All Close All Description Iron-refractory iron deficiency anemia is one of many types of anemia , which ...

  15. Iron and stony-iron meteorites

    DEFF Research Database (Denmark)

    Benedix, Gretchen K.; Haack, Henning; McCoy, T. J.

    2014-01-01

    Without iron and stony-iron meteorites, our chances of ever sampling the deep interior of a differentiated planetary object would be next to nil. Although we live on a planet with a very substantial core, we will never be able to sample it. Fortunately, asteroid collisions provide us with a rich...... sampling of the deep interiors of differentiated asteroids. Iron and stony-iron meteorites are fragments of a large number of asteroids that underwent significant geological processing in the early solar system. Parent bodies of iron and some stony-iron meteorites completed a geological evolution similar...... to that continuing on Earth – although on much smaller length- and timescales – with melting of the metal and silicates; differentiation into core, mantle, and crust; and probably extensive volcanism. Iron and stony-iron meteorites are our only available analogues to materials found in the deep interiors of Earth...

  16. Iron from Zealandic bog iron ore -

    DEFF Research Database (Denmark)

    Lyngstrøm, Henriette Syrach

    2011-01-01

    og geologiske materiale, metallurgiske analyser og eksperimentel arkæologiske forsøg - konturerne af en jernproduktion med udgangspunkt i den sjællandske myremalm. The frequent application by archaeologists of Werner Christensen’s distribution map for the occurrence of bog iron ore in Denmark (1966...... are sketched of iron production based on bog iron ore from Zealand....

  17. Liver iron transport

    Institute of Scientific and Technical Information of China (English)

    Ross M Graham; Anita CG Chua; Carly E Herbison; John K Olynyk; Debbie Trinder

    2007-01-01

    The liver plays a central role in iron metabolism. It is the major storage site for iron and also expresses a complex range of molecules which are involved in iron transport and regulation of iron homeostasis. An increasing number of genes associated with hepatic iron transport or regulation have been identified. These include transferrin receptors (TFR1 and 2), a ferrireductase (STEAP3), the transporters divalent metal transporter-1 (DMT1) and ferroportin (FPN) as well as the haemochromatosis protein, HFE and haemojuvelin (HJV),which are signalling molecules. Many of these genes also participate in iron regulatory pathways which focus on the hepatic peptide hepcidin. However, we are still only beginning to understand the complex interactions between liver iron transport and iron homeostasis. This review outlines our current knowledge of molecules of iron metabolism and their roles in iron transport and regulation of iron homeostasis.

  18. Broad Prize: Do the Successes Spread?

    Science.gov (United States)

    Samuels, Christina A.

    2011-01-01

    When the Broad Prize for Urban Education was created in 2002, billionaire philanthropist Eli Broad said he hoped the awards, in addition to rewarding high-performing school districts, would foster healthy competition; boost the prestige of urban education, long viewed as dysfunctional; and showcase best practices. Over the 10 years the prize has…

  19. [Iron-refractory iron deficiency anemia].

    Science.gov (United States)

    Kawabata, Hiroshi

    2016-02-01

    The major causes of iron deficiency anemia (IDA) include iron loss due to bleeding, increased iron requirements, and decreased iron absorption by the intestine. The most common cause of IDA in Japanese women is iron loss during menstruation. Autoimmune atrophic gastritis and Helicobacter pylori infection can also cause IDA by reducing intestinal iron absorption. In addition to these common etiologies, germline mutations of TMPRSS6 can cause iron-refractory IDA (IRIDA). TMPRSS6 encodes matriptase-2, a membrane-bound serine protease primarily expressed in the liver. Functional loss of matriptase-2 due to homozygous mutations results in an increase in the expression of hepcidin, which is the key regulator of systemic iron homeostasis. The serum hepcidin increase in turn leads to a decrease in iron supply from the intestine and macrophages to erythropoietic cells. IRIDA is microcytic and hypochromic, but decreased serum ferritin is not observed as in IDA. IRIDA is refractory to oral iron supplementation, but does respond to intravenous iron supplementation to some extent. Because genetic testing is required for the diagnoses of IRIDA, a considerable number of cases may go undiagnosed and may thus be overlooked. PMID:26935626

  20. [Iron-refractory iron deficiency anemia].

    Science.gov (United States)

    Kawabata, Hiroshi

    2016-02-01

    The major causes of iron deficiency anemia (IDA) include iron loss due to bleeding, increased iron requirements, and decreased iron absorption by the intestine. The most common cause of IDA in Japanese women is iron loss during menstruation. Autoimmune atrophic gastritis and Helicobacter pylori infection can also cause IDA by reducing intestinal iron absorption. In addition to these common etiologies, germline mutations of TMPRSS6 can cause iron-refractory IDA (IRIDA). TMPRSS6 encodes matriptase-2, a membrane-bound serine protease primarily expressed in the liver. Functional loss of matriptase-2 due to homozygous mutations results in an increase in the expression of hepcidin, which is the key regulator of systemic iron homeostasis. The serum hepcidin increase in turn leads to a decrease in iron supply from the intestine and macrophages to erythropoietic cells. IRIDA is microcytic and hypochromic, but decreased serum ferritin is not observed as in IDA. IRIDA is refractory to oral iron supplementation, but does respond to intravenous iron supplementation to some extent. Because genetic testing is required for the diagnoses of IRIDA, a considerable number of cases may go undiagnosed and may thus be overlooked.

  1. Nutritional iron deficiency

    NARCIS (Netherlands)

    Zimmermann, M.B.; Hurrell, R.F.

    2007-01-01

    Iron deficiency is one of the leading risk factors for disability and death worldwide, affecting an estimated 2 billion people. Nutritional iron deficiency arises when physiological requirements cannot be met by iron absorption from diet. Dietary iron bioavailability is low in populations consuming

  2. Special thermite cast irons

    OpenAIRE

    Yu. Zhiguts; I. Kurytnik

    2008-01-01

    The given paper deals with the problems of the synthesis of cast iron by metallothermy synthesis. On the basis of investigated method of calculations structures of charges have been arranged and cast iron has been synthesized further. Peculiarities metallothermic smelting were found, mechanical properties and structure of received cast iron were investigated and different technologies for cast iron receiving were worked out.

  3. The line emissions and polarization in blazars

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The correlations between broad-line emission,polarization,and core-dominance parameters are investigated for a sample of 148 blazars(BL Lacertae objects-BLs and flat spectrum radio quasars-FSRQs). An anti-correlation between the broad-line luminosity and the linear polarization is found. The broad-line and polarization relation can be explained by using a relativistic beaming model,which perhaps suggests that BL Lacs and FSRQs are a single class. We also investigated the relation between the ratio of the broad-line luminosity to the Eddington luminosity and linear polarization,and that between the ratio of the broad-line luminosity to the Eddington luminosity and the core-dominance parameter.

  4. Iron bromide vapor laser

    Science.gov (United States)

    Sukhanov, V. B.; Shiyanov, D. V.; Trigub, M. V.; Dimaki, V. A.; Evtushenko, G. S.

    2016-03-01

    We have studied the characteristics of a pulsed gas-discharge laser on iron bromide vapor generating radiation with a wavelength of 452.9 nm at a pulse repetition frequency (PRF) of 5-30 kHz. The maximum output power amounted to 10 mW at a PRF within 5-15 kHz for a voltage of 20-25 kV applied to electrodes of the discharge tube. Addition of HBr to the medium produced leveling of the radial profile of emission. Initial weak lasing at a wavelength of 868.9 nm was observed for the first time, which ceased with buildup of the main 452.9-nm line.

  5. Iron oxide surfaces

    Science.gov (United States)

    Parkinson, Gareth S.

    2016-03-01

    The current status of knowledge regarding the surfaces of the iron oxides, magnetite (Fe3O4), maghemite (γ-Fe2O3), haematite (α-Fe2O3), and wüstite (Fe1-xO) is reviewed. The paper starts with a summary of applications where iron oxide surfaces play a major role, including corrosion, catalysis, spintronics, magnetic nanoparticles (MNPs), biomedicine, photoelectrochemical water splitting and groundwater remediation. The bulk structure and properties are then briefly presented; each compound is based on a close-packed anion lattice, with a different distribution and oxidation state of the Fe cations in interstitial sites. The bulk defect chemistry is dominated by cation vacancies and interstitials (not oxygen vacancies) and this provides the context to understand iron oxide surfaces, which represent the front line in reduction and oxidation processes. Fe diffuses in and out from the bulk in response to the O2 chemical potential, forming sometimes complex intermediate phases at the surface. For example, α-Fe2O3 adopts Fe3O4-like surfaces in reducing conditions, and Fe3O4 adopts Fe1-xO-like structures in further reducing conditions still. It is argued that known bulk defect structures are an excellent starting point in building models for iron oxide surfaces. The atomic-scale structure of the low-index surfaces of iron oxides is the major focus of this review. Fe3O4 is the most studied iron oxide in surface science, primarily because its stability range corresponds nicely to the ultra-high vacuum environment. It is also an electrical conductor, which makes it straightforward to study with the most commonly used surface science methods such as photoemission spectroscopies (XPS, UPS) and scanning tunneling microscopy (STM). The impact of the surfaces on the measurement of bulk properties such as magnetism, the Verwey transition and the (predicted) half-metallicity is discussed. The best understood iron oxide surface at present is probably Fe3O4(100); the structure is

  6. Magnetic properties of a new iron lead vanadate Pb2FeV3O11

    International Nuclear Information System (INIS)

    Highlights: → We study magnetic properties of a new iron lead vanadate Pb2FeV3O11. → We employ dc/ac magnetic susceptibility and electron paramagnetic resonance methods. → We detected the existence of AF phase below 2.5 K. → EPR spectrum reflects the presence of two types of Fe3+-Fe3+ pairs. → EPR and magnetic susceptibility are complementary methods revealing different aspects of magnetic interactions. - Abstract: Temperature dependence of dc/ac magnetization and electron paramagnetic resonance (EPR) spectra of Pb2FeV3O11 iron lead vanadate has been investigated. The dc magnetic measurements have shown the presence of antiferromagnetic interactions with Curie-Weiss temperature, TCW = -15.2 K, in the high temperatures range while the field cooled (FC) magnetization revealed a maximum at TN = 2.5 K which coincides with a long range magnetic ordering. Temperature dependence of χ' has shown a maximum at the same temperature. EPR spectrum of Pb2FeV3O11 at room temperature is dominated by nearly symmetrical, very intense and broad resonance line centered at geff ∼ 2.0 that could be attributed to the correlated system of iron ions. The temperature dependence of magnetic resonance parameters (amplitude, g-factor, linewidth, integrated intensity) has been determined in the 4-300 K range and it suggests the existence of short range correlated spin system up to high temperatures. The temperature dependence of the amplitude of the resonance line has shown a pronounced maximum at 12.5 K that indicates on the existence of two subsystems of weakly and strongly coupled iron pairs. Comparison of dc magnetic susceptibility and EPR integrated intensity points to the presence of correlated spin agglomerates that play an important role in determination of the magnetic response of Pb2FeV3O11.

  7. Measuring Prevention More Broadly, An Empirical...

    Data.gov (United States)

    U.S. Department of Health & Human Services — Measuring Prevention More Broadly, An Empirical Assessment of CHIPRA Core Measures Differences in CHIP design and structure, across states and over time, may limit...

  8. BROAD PHONEME CLASSIFICATION USING SIGNAL BASED FEATURES

    Directory of Open Access Journals (Sweden)

    Deekshitha G

    2014-12-01

    Full Text Available Speech is the most efficient and popular means of human communication Speech is produced as a sequence of phonemes. Phoneme recognition is the first step performed by automatic speech recognition system. The state-of-the-art recognizers use mel-frequency cepstral coefficients (MFCC features derived through short time analysis, for which the recognition accuracy is limited. Instead of this, here broad phoneme classification is achieved using features derived directly from the speech at the signal level itself. Broad phoneme classes include vowels, nasals, fricatives, stops, approximants and silence. The features identified useful for broad phoneme classification are voiced/unvoiced decision, zero crossing rate (ZCR, short time energy, most dominant frequency, energy in most dominant frequency, spectral flatness measure and first three formants. Features derived from short time frames of training speech are used to train a multilayer feedforward neural network based classifier with manually marked class label as output and classification accuracy is then tested. Later this broad phoneme classifier is used for broad syllable structure prediction which is useful for applications such as automatic speech recognition and automatic language identification.

  9. Simultaneous NuSTAR and XMM-Newton 0.5-80 keV spectroscopy of the narrow-line Seyfert 1 galaxy SWIFT J2127.4+5654

    DEFF Research Database (Denmark)

    Marinucci, A.; Matt, G.; Kara, E.;

    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 ks performed during three XMM-Newton orbits. We detect a relativistic broadened ironline origin...... broad as in other sources that have maximally spinning black holes. The lag amplitude suggests a continuum-to-reprocessor distance of about 10-20 rg. These timing results independently support an intermediate black hole spin and a compact corona....... originating from the innermost regions of the accretion disc surrounding the central black hole, from which we infer an intermediate spin of a = 0.58−0.17+0.11. The intrinsic spectrum is steep (Γ = 2.08 ± 0.01) as commonly found in narrow-line Seyfert 1 galaxies, while the cutoff energy (Ec = 108−10+11 ke...

  10. Hunger for iron: the alternative siderophore iron scavenging systems in highly virulent Yersinia.

    Directory of Open Access Journals (Sweden)

    Alexander eRakin

    2012-11-01

    Full Text Available Low molecular weight siderophores are used by many living organisms to scavenge scarcely available ferric iron. Presence of at least a single siderophore-based iron acquisition system is usually acknowledged as a virulence-associated trait and a prerequisite to become an efficient and successful pathogen. Currently it is assumed that yersiniabactin (Ybt is the solely functional endogenous siderophore iron uptake system in highly virulent Yersinia (Yersinia pestis, Y. pseudotuberculosis and Y. enterocolitica biotype 1B. Genes responsible for biosynthesis, transport and regulation of the yersiniabactin (ybt production are clustered on a mobile genetic element, the High Pathogenicity Island (HPI that is responsible for broad dissemination of the ybt genes in Enterobacteriaceae. However, the ybt gene cluster is absent from nearly half of Y. pseudotuberculosis O3 isolates and epidemic Y. pseudotuberculosis O1 isolates responsible for the Far East Scarlet-like Fever. Several potential siderophore-mediated iron uptake gene clusters are documented in Yersinia genomes, however neither of them have been proven to be functional. It has been suggested that at least two siderophores alternative to Ybt may operate in the highly virulent Yersinia pestis / Y. pseudotuberculosis group, and are referred to as pseudochelin (Pch and yersiniachelin (Ych. Furthermore, most sporadic Y. pseudotuberculosis O1 strains possess gene clusters encoding all three iron scavenging systems. Thus, the Ybt system appears not to be the sole endogenous siderophore iron uptake system in the highly virulent yersiniae and may be efficiently substituted and / or supplemented by alternative iron scavenging systems.

  11. On-line moisture analysis

    CERN Document Server

    Cutmore, N G

    2002-01-01

    Measurement of the moisture content of iron ore has become a key issue for controlling moisture additions for dust suppression. In most cases moisture content is still determined by manual or automatic sampling of the ore stream, followed by conventional laboratory analysis by oven drying. Although this procedure enables the moisture content to be routinely monitored, it is too slow for control purposes. This has generated renewed interest in on-line techniques for the accurate and rapid measurement of moisture in iron ore on conveyors. Microwave transmission techniques have emerged over the past 40 years as the dominant technology for on-line measurement of moisture in bulk materials, including iron ores. Alternative technologies have their limitations. Infra-red analysers are used in a variety of process industries, but rely on the measurement of absorption by moisture in a very thin surface layer. Consequently such probes may be compromised by particle size effects and biased presentation of the bulk mater...

  12. Calculation of self-diffusion coefficients in iron

    OpenAIRE

    Baohua Zhang

    2014-01-01

    On the basis of available P-V-T equation of state of iron, the temperature and pressure dependence of self-diffusion coefficients in iron polymorphs (α, δ, γ and ɛ phases) have been successfully reproduced in terms of the bulk elastic and expansivity data by means of a thermodynamical model that interconnects point defects parameters with bulk properties. The calculated diffusion parameters, such as self-diffusion coefficient, activation energy and activation volume over a broad temperature r...

  13. Simultaneous NuSTAR and XMM-Newton 0.5-80 KeV Spectroscopy of the Narrow-Line Seyfert 1 Galaxy SWIFT J2127.4+5654

    Science.gov (United States)

    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.

  14. Discovery of Iron in PG1159 Stars

    CERN Document Server

    Werner, K; Kruk, J W

    2010-01-01

    The lack of FeVII lines in PG1159 stars had led to the conclusion that in some objects iron must be strongly depleted. We have now detected FeX lines in FUSE spectra of the very hottest PG1159 stars Teff=150,000 - 200,000 K; RXJ2117.1+3412, K1-16, NGC 246, Longmore 4). Surprisingly, we derive a solar iron abundance. It is conspicuous that they are among the most massive PG1159 stars (0.71-0.82 Msun), in contrast to those objects for which strongest Fe-deficiency was claimed (0.53-0.56 Msun). Based on new FeVIII line identifications in SOHO/SUMER UV spectra of the Sun, we were able to detect these lines in FUSE spectra of several "cooler" (Teff<150,000 K) objects, among them is the prototype PG1159-035. An abundance analysis is in progress.

  15. Discovery of Iron in PG1159 Stars

    Science.gov (United States)

    Werner, Klaus; Rauch, Thomas; Kruk, Jeffrey W.

    2010-11-01

    The lack of Fe VII lines in PG1159 stars had led to the conclusion that in some objects iron must be strongly depleted. We have now detected Fe X lines in FUSE spectra of the very hottest PG1159 stars (Teff = 150 000-200 000 KRX J2117.1+3412, K1-16, NGC 246, Longmore4). Surprisingly, we derive a solar iron abundance. It is conspicuous that they are among the most massive PG1159 stars (0.71-0.82 Msolar), in contrast to those objects for which strongest Fe-deficiency was claimed (0.53-0.56 Msolar). Based on new Fe VIII line identifications in SOHO/SUMER UV spectra of the Sun, we were able to detect these lines in FUSE spectra of several ``cooler'' (Teff<~150 000) objects, among them is the prototype PG1159-035. An abundance analysis is in progress.

  16. Silicon micromachined broad band light source

    Science.gov (United States)

    George, Thomas (Inventor); Jones, Eric (Inventor); Tuma, Margaret L. (Inventor); Eastwood, Michael (Inventor); Hansler, Richard (Inventor)

    2004-01-01

    A micro electromechanical system (MEMS) broad band incandescent light source includes three layers: a top transmission window layer; a middle filament mount layer; and a bottom reflector layer. A tungsten filament with a spiral geometry is positioned over a hole in the middle layer. A portion of the broad band light from the heated filament is reflective off the bottom layer. Light from the filament and the reflected light of the filament are transmitted through the transmission window. The light source may operate at temperatures of 2500 K or above. The light source may be incorporated into an on board calibrator (OBC) for a spectrometer.

  17. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... intravenous iron therapy. Rate This Content: NEXT >> Featured Video Living With and Managing Iron-Deficiency Anemia 05/18/2011 This video—presented by the National Heart, Lung, and Blood ...

  18. Total iron binding capacity

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003489.htm Total iron binding capacity To use the sharing features on this page, please enable JavaScript. Total iron binding capacity (TIBC) is a blood test to ...

  19. Iron supplements (image)

    Science.gov (United States)

    The mineral iron is an essential nutrient for humans because it is part of blood cells, which carry oxygen to all body cells. There is no conclusive evidence that iron supplements contribute to heart attacks.

  20. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... This Content: NEXT >> Featured Video Living With and Managing Iron-Deficiency Anemia 05/18/2011 This video— ... treatment. For more information about living with and managing iron-deficiency anemia, go to the Health Topics ...

  1. Serum iron test

    Science.gov (United States)

    ... of iron homeostasis: iron deficiency and overload. In: Hoffman R, Benz EJ Jr, Silberstein LE, et al, ... EJ, Gardner LB. Anemia of chronic diseases. In: Hoffman R, Benz EJ Jr, Silberstein LE, et al, ...

  2. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... levels usually are due to blood loss, poor diet, or an inability to absorb enough iron from ... iron levels. Susan also made changes to her diet, such as focusing more on green leafy vegetables, ...

  3. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... iron-rich protein that carries oxygen from the lungs to the rest of the body. Iron-deficiency ... 2011 This video—presented by the National Heart, Lung, and Blood Institute, part of the National Institutes ...

  4. Special thermite cast irons

    Directory of Open Access Journals (Sweden)

    Yu. Zhiguts

    2008-07-01

    Full Text Available The given paper deals with the problems of the synthesis of cast iron by metallothermy synthesis. On the basis of investigated method of calculations structures of charges have been arranged and cast iron has been synthesized further. Peculiarities metallothermic smelting were found, mechanical properties and structure of received cast iron were investigated and different technologies for cast iron receiving were worked out.

  5. Iron deficiency and cognition

    OpenAIRE

    Hulthén, Lena

    2003-01-01

    Iron deficiency is the most prevalent nutritional disorder in the world. One of the most worrying consequences of iron deficiency in children is the alteration of behaviour and cognitive performance. In iron-deficient children, striking behavioural changes are observed, such as reduced attention span, reduced emotional responsiveness and low scores on tests of intelligence. Animal studies on nutritional iron deficiency show effects on learning ability that parallel the human studies. Despite ...

  6. Alternative iron making routes

    Energy Technology Data Exchange (ETDEWEB)

    Kaushik, P.; Sharma, T. [Indian School of Mines, Dhanbad (India)

    2002-07-01

    The versatile route of iron production 'blast furnace' technique is being replaced by widely accepted Corex technology, Midrex process using Fastmelt ironmaking, eco-friendly Romelt process, more innovative Ausmelt & Hismelt technology, TATA KORF Mini blast furnace improvement, 'quickest iron through Orbiting Plasma', Direct iron ore smelting process, Conred, AISI-Hyl, Inred processes, Direct iron ore reduction methods, their comparison and proposed modifications. 18 refs., 11 figs., 14 tabs.

  7. Iron-Deficiency Anemia

    Science.gov (United States)

    ... page from the NHLBI on Twitter. What Is Iron-Deficiency Anemia? Español Iron-deficiency anemia is a common, ... Content: NEXT >> Featured Video Living With and Managing Iron-Deficiency Anemia 05/18/2011 This video—presented by ...

  8. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... the body. Iron-deficiency anemia usually develops over time if your body doesn't have enough iron ... Institutes of Health—shows how Susan, a full-time worker and student, has coped with having iron- ...

  9. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... the NHLBI on Twitter. What Is Iron-Deficiency Anemia? Español Iron-deficiency anemia is a common, easily ... Featured Video Living With and Managing Iron-Deficiency Anemia 05/18/2011 This video—presented by the ...

  10. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... body. Low iron levels usually are due to blood loss, poor diet, or an inability to absorb enough iron from food. Overview Iron-deficiency anemia is a common type of anemia . The term "anemia" usually refers to ...

  11. The GREGOR Broad-Band Imager

    Science.gov (United States)

    von der Lühe, O.; Volkmer, R.; Kentischer, T. J.; Geißler, R.

    2012-11-01

    The design and characteristics of the Broad-Band Imager (BBI) of GREGOR are described. BBI covers the visible spectral range with two cameras simultaneously for a large field and with critical sampling at 390 nm, and it includes a mode for observing the pupil in a Foucault configuration. Samples of first-light observations are shown.

  12. Broad resonances and beta-decay

    DEFF Research Database (Denmark)

    Riisager, K.; Fynbo, H. O. U.; Hyldegaard, S.;

    2015-01-01

    Beta-decay into broad resonances gives a distorted lineshape in the observed energy spectrum. Part of the distortion arises from the phase space factor, but we show that the beta-decay matrix element may also contribute. Based on a schematic model for p-wave continuum neutron states it is argued...

  13. Iron and the liver.

    Science.gov (United States)

    Pietrangelo, Antonello

    2016-01-01

    Humans have evolved to retain iron in the body and are exposed to a high risk of iron overload and iron-related toxicity. Excess iron in the blood, in the absence of increased erythropoietic needs, can saturate the buffering capacity of serum transferrin and result in non-transferrin-bound highly reactive forms of iron that can cause damage, as well as promote fibrogenesis and carcinogenesis in the parenchymatous organs. A number of hereditary or acquired diseases are associated with systemic or local iron deposition or iron misdistribution in organs or cells. Two of these, the HFE- and non-HFE hemochromatosis syndromes represent the paradigms of genetic iron overload. They share common clinical features and the same pathogenic basis, in particular, a lack of synthesis or activity of hepcidin, the iron hormone. Before hepcidin was discovered, the liver was simply regarded as the main site of iron storage and, as such, the main target of iron toxicity. Now, as the main source of hepcidin, it appears that the loss of the hepcidin-producing liver mass or genetic and acquired factors that repress hepcidin synthesis in the liver may also lead to iron overload. Usually, there is low-grade excess iron which, through oxidative stress, is sufficient to worsen the course of the underlying liver disease or other chronic diseases that are apparently unrelated to iron, such as chronic metabolic and cardiovascular diseases. In the future, modulation of hepcidin synthesis and activity or hepcidin hormone-replacing strategies may become therapeutic options to cure iron-related disorders.

  14. Decoupling of Iron and Phosphate in the Global Ocean

    Science.gov (United States)

    Parekh, Payal

    2003-01-01

    Iron is an essential micronutrient for marine phytoplankton, limiting their growth in high nutrient, low chlorophyll regions of the ocean. I use a hierarchy of ocean circulation and biogeochemistry models to understand controls on global iron distribution. I formulate a mechanistic model of iron cycling which includes scavenging onto sinking particles and complexation with an organic ligand. The iron cycle is coupled to a phosphorus cycling model. Iron's aeolian source is prescribed. In the context of a highly idealized multi-box model scheme, the model can be brought into consistency with the relatively sparse ocean observations of iron in the oceans. This biogeochemical scheme is also implemented in a coarse resolution ocean general circulation model. This model also successfully reproduces the broad regional patterns of iron and phosphorus. In particular, the high macronutrient concentrations of the Southern Ocean result from iron limitation in the model. Due to the potential ability of iron to change the efficiency of the carbon pump in the remote Southern Ocean, I study Southern Ocean surface phosphate response to increased aeolian dust flux. My box model and GCM results suggest that a global ten fold increase in dust flux can support a phosphate drawdown of 0.25-0.5 micromolar.

  15. Theoretical Study of Radiation from a Broad Range of Impurity Ions for Magnetic Fusion Diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Safronova, Alla [Univ. of Nevada, Reno, NV (United States)

    2014-03-14

    Spectroscopy of radiation emitted by impurities plays an important role in the study of magnetically confined fusion plasmas. The measurements of these impurities are crucial for the control of the general machine conditions, for the monitoring of the impurity levels, and for the detection of various possible fault conditions. Low-Z impurities, typically present in concentrations of 1%, are lithium, beryllium, boron, carbon, and oxygen. Some of the common medium-Z impurities are metals such as iron, nickel, and copper, and high-Z impurities, such as tungsten, are present in smaller concentrations of 0.1% or less. Despite the relatively small concentration numbers, the aforementioned impurities might make a substantial contribution to radiated power, and also influence both plasma conditions and instruments. A detailed theoretical study of line radiation from impurities that covers a very broad spectral range from less than 1 Å to more than 1000 Å has been accomplished and the results were applied to the LLNL Electron Beam Ion Trap (EBIT) and the Sustained Spheromak Physics Experiment (SSPX) and to the National Spherical Torus Experiment (NSTX) at Princeton. Though low- and medium-Z impurities were also studied, the main emphasis was made on the comprehensive theoretical study of radiation from tungsten using different state-of-the-art atomic structure codes such as Relativistic Many-Body Perturbation Theory (RMBPT). The important component of this research was a comparison of the results from the RMBPT code with other codes such as the Multiconfigurational Hartree–Fock developed by Cowan (COWAN code) and the Multiconfiguration Relativistic Hebrew University Lawrence Atomic Code (HULLAC code), and estimation of accuracy of calculations. We also have studied dielectronic recombination, an important recombination process for fusion plasma, for variety of highly and low charged tungsten ions using COWAN and HULLAC codes. Accurate DR rate coefficients are needed for

  16. [Iron function and carcinogenesis].

    Science.gov (United States)

    Akatsuka, Shinya; Toyokuni, Shinya

    2016-07-01

    Though iron is an essential micronutrient for humans, the excess state is acknowledged to be associated with oncogenesis. For example, iron overload in the liver of the patients with hereditary hemocromatosis highly increases the risk of hepatocellular carcinoma. Also, as to asbestos-related mesothelioma, such kinds of asbestos with a higher iron content are considered to be more carcinogenic. Iron is a useful element, which enables fundamental functions for life such as oxygen carrying and electron transport. However, in the situation where organisms are unable to have good control of it, iron turns into a dangerous element which catalyzes generation of reactive oxygen. In this review, I first outline the relationships between iron and cancer in general, then give an explanation about iron-related animal carcinogenesis models.

  17. Variation and inheritance of iron reductase activity in the roots of common bean (Phaseolus vulgaris L. and association with seed iron accumulation QTL

    Directory of Open Access Journals (Sweden)

    Fernandez Andrea C

    2010-10-01

    Full Text Available Abstract Background Iron deficiency anemia is a global problem which often affects women and children of developing countries. Strategy I plants, such as common bean (Phaseolus vulgaris L. take up iron through a process that involves an iron reduction mechanism in their roots; this reduction is required to convert ferric iron to ferrous iron. Root absorbed iron is critical for the iron nutrition of the plant, and for the delivery of iron to the shoot and ultimately the seeds. The objectives of this study were to determine the variability and inheritance for iron reductase activity in a range of genotypes and in a low × high seed iron cross (DOR364 × G19833, to identify quantitative trait loci (QTL for this trait, and to assess possible associations with seed iron levels. Results The experiments were carried out with hydroponically grown plants provided different amounts of iron varying between 0 and 20 μM Fe(III-EDDHA. The parents, DOR364 and G19833, plus 13 other cultivated or wild beans, were found to differ in iron reductase activity. Based on these initial experiments, two growth conditions (iron limited and iron sufficient were selected as treatments for evaluating the DOR364 × G19833 recombinant inbred lines. A single major QTL was found for iron reductase activity under iron-limited conditions (1 μM Fe on linkage group b02 and another major QTL was found under iron sufficient conditions (15 μM Fe on linkage group b11. Associations between the b11 QTL were found with several QTL for seed iron. Conclusions Genes conditioning iron reductase activity in iron sufficient bean plants appear to be associated with genes contributing to seed iron accumulation. Markers for bean iron reductase (FRO homologues were found with in silico mapping based on common bean synteny with soybean and Medicago truncatula on b06 and b07; however, neither locus aligned with the QTL for iron reductase activity. In summary, the QTL for iron reductase activity

  18. Crx broadly modulates the pineal transcriptome

    OpenAIRE

    Rovsing, Louise; Clokie, Samuel; Bustos, Diego M.; Rohde, Kristian; Steven L Coon; Litman, Thomas; Rath, Martin F.; Møller, Morten; Klein, David C.

    2011-01-01

    Cone-rod homeobox (Crx) encodes Crx, a transcription factor expressed selectively in retinal photoreceptors and pinealocytes, the major cell type of the pineal gland. Here, the influence of Crx on the mammalian pineal gland was studied by light and electron microscopy and by use of microarray and qRTPCR technology, thereby extending previous studies on selected genes (Furukawa et al. 1999). Deletion of Crx was not found to alter pineal morphology, but was found to broadly modulate the mouse p...

  19. A Broad View of Macroeconomic Stability

    OpenAIRE

    José Antonio Ocampo

    2005-01-01

    This paper recommends a broad concept of macroeconomic stability, whereby “sound macroeconomic frameworks” include not only price stability and sound fiscal policies, but also a well-functioning real economy, sustainable debt ratios and healthy public and private sector balance sheets. These multiple dimensions imply using multiple policy instruments. The paper elaborates a framework for developing countries that involves active use of counter-cyclical macroeconomic policies (exchange rate, m...

  20. The ubiquity of iron.

    Science.gov (United States)

    Frey, Perry A; Reed, George H

    2012-09-21

    The importance of iron in living systems can be traced to the many complexes within which it is found, to its chemical mobility in undergoing oxidation-reduction reactions, and to the abundance of iron in Earth's crust. Iron is the most abundant element, by mass, in the Earth, constituting about 80% of the inner and outer cores of Earth. The molten outer core is about 8000 km in diameter, and the solid inner core is about 2400 km in diameter. Iron is the fourth most abundant element in Earth's crust. It is the chemically functional component of mononuclear iron complexes, dinuclear iron complexes, [2Fe-2S] and [4Fe-4S] clusters, [Fe-Ni-S] clusters, iron protophorphyrin IX, and many other complexes in protein biochemistry. Metals such as nickel, cobalt, copper, and manganese are present in the crust and could in principle function chemically in place of iron, but they are scarce in Earth's crust. Iron is plentiful because of its nuclear stability in stellar nuclear fusion reactions. It seems likely that other solid planets, formed by the same processes as Earth, would also foster the evolution of life and that iron would be similarly important to life on those planets as it is on Earth.