X-ray Absorption and Reflection in Active Galactic Nuclei

Abstract

X-ray spectroscopy offers an opportunity to study the complex mixture of emitting and absorbing components in the circumnuclear regions of active galactic nuclei, and to learn about the accretion process that fuels AGN and the feedback of material to their host galaxies. We describe the spectral signatures that may be studied and review the X-ray spectra and spectral variability of active galaxies, concentrating on progress from recent Chandra, XMM-Newton and Suzaku data for local type 1 AGN. We describe the evidence for absorption covering a wide range of column densities, ionization and dynamics, and discuss the growing evidence for partial-covering absorption from data at energies > 10 keV. Such absorption can also explain the observed X-ray spectral curvature and variability in AGN at lower energies and is likely an important factor in shaping the observed properties of this class of source. Consideration of self-consistent models for local AGN indicates that X-ray spectra likely comprise a combination of absorption and reflection effects from material originating within a few light days of the black hole as well as on larger scales. It is likely that AGN X-ray spectra may be strongly affected by the presence of disk-wind outflows that are expected in systems with high accretion rates, and we describe models that attempt to predict the effects of radiative transfer through such winds, and discuss the prospects for new data to test and address these ideas.

Accepted for publication in the Astronomy and Astrophysics Review. 58 pages, 9 figures. V2 has fixed an error in footnote 1

References in corpus (161)

• A Fundamental Relation Between Supermassive Black Holes and Their Host Galaxies
• The Demography of Massive Dark Objects in Galaxy Centres
• A Relationship Between Nuclear Black Hole Mass and Galaxy Velocity Dispersion
• The slope of the black-hole mass versus velocity dispersion correlation
• Advection-Dominated Accretion: A Self-Similar Solution
• Reverberation Measurements for 17 Quasars and the Size-Mass-Luminosity Relations in Active Galactic Nuclei
• Central Masses and Broad-Line Region Sizes of Active Galactic Nuclei. II. A Homogeneous Analysis of a Large Reverberation-Mapping Database
• The Relation between Black Hole Mass, Bulge Mass, and Near-Infrared Luminosity
• Local Supermassive Black Holes, Relics of Active Galactic Nuclei and the X-ray Background
• Observational constraints on growth of massive black holes
• Dynamics of line-driven disk winds in Active Galactic Nuclei
• Present-Day Growth of Black Holes and Bulges: the SDSS Perspective
• AGN Black Hole Masses and Bolometric Luminosities
• Central Masses and Broad-Line Region Sizes of Active Galactic Nuclei: I. Comparing the Photoionization and Reverberation Techniques
• Supermassive Black Holes in Active Galactic Nuclei. II. Calibration of the M-sigma Relationship for AGNs
• An XMM-Newton survey of broad iron lines in Seyfert galaxies
• Thermal Equilibria of Accretion Disks
• ASCA observations of Seyfert 1 galaxies: II. Relativistic Iron K-alpha emission
• An X-ray spectral study of 24 type-1 AGN
• The 2dF QSO Redshift Survey - I. The Optical QSO Luminosity Function
• Constraining Black Hole Spin Via X-ray Spectroscopy
• Dynamics of Line-Driven Disk Winds in Active Galactic Nuclei II: Effects of Disk Radiation
• A light bending model for the X-ray temporal and spectral properties of accreting black holes
• An Explanation for the soft X-ray excess in AGN
• A 3 dimensional diagnostic diagram for Seyfert 2s: probing X-ray absorption and Compton thickness
• Is the soft excess in AGN real?
• Fluorescent iron lines as a probe of astrophysical black hole systems
• A high velocity ionised outflow and XUV photosphere in the narrow emission line quasar PG1211+143
• The Spectral Energy Distributions of Low-Luminosity Active Galactic Nuclei
• Black Hole Winds
• The nature and origin of Seyfert warm absorbers
• Broad Emission Line Shifts in Quasars: An Orientation Measure for Radio-Quiet Quasars?
• A Correlation between Galaxy Light Concentration and Supermassive Black Hole Mass
• ASCA Observations of Seyfert 1 galaxies: III. The Evidence for Absorption & Emission due to Photoionized Gas
• The Contribution of the Obscuring Torus to the X--Ray Spectrum of Seyfert Galaxies: A Test for the Unification Model
• Photoionization Modeling and the K Lines of Iron
• XMM-EPIC observation of MCG-6-30-15: Direct evidence for the extraction of energy from aspinning black hole?
• X-ray photoionized plasma diagnostics with Helium-like ions. Application to Warm Absorber-Emitter in Active Galactic Nuclei
• The Ionized Gas and Nuclear Environment in NGC 3783. I. Time-Averaged 900 ks Chandra Grating Spectroscopy
• ASCA observations of Seyfert 1 galaxies: I. Data Analysis, Imaging and Timing
• A Massive X-Ray Outflow from the Quasar PDS 456
• Swift BAT Survey of AGN
• Evidence for Supermassive Black Holes in Active Galactic Nuclei from Emission-Line Reverberation
• Chandra Detects Relativistic Broad Absorption Lines from APM 08279+5255
• A Comprehensive Spectral and Variability Study of Narrow-Line Seyfert 1 Galaxies Observed by ASCA: I. Observations and Time Series Analysis
• X-ray reflection spectra from ionized slabs
• Occultation measurement of the size of the X-ray emitting region in the Active Galactic Nucleus of NGC 1365
• Thermal Instability and Photoionized X-ray Reflection in Accretion Disks
• XMM-NEWTON Reveals the Quasar Outflow in PG 1115+080
• The Ionized Gas and Nuclear Environment in NGC 3783. IV. Variability and Modeling of the 900 ks CHANDRA Spectrum
• A soft X-ray study of Type I AGN observed with Chandra HETGS
• Observable Properties of X-ray Heated Winds in AGN: Warm Reflectors and Warm Absorbers
• The lack of variability of the iron line in MCG-6-30-15: general relativistic effects
• Toward a Self Consistent Model of the Ionized Absorber in NGC 3783
• Complex resonance absorption structure in the X-ray spectrum of IRAS13349+2438
• Revealing the Dusty Warm Absorber in MCG--6-30-15 with the Chandra HETG
• High-Resolution X-ray Spectroscopy and Modeling of the Absorbing and Emitting Outflow in NGC 3783
• Unabsorbed Seyfert 2 galaxies
• A long, hard look at MCG-6-30-15 with XMM-Newton II: detailed EPIC analysis and modelling
• On why the Iron K-shell absorption in AGN is not a signature of the local Warm/Hot Intergalactic Medium
• The iron line in MCG-6-30-15 from XMM-Newton: evidence for gravitational light-bending?
• On X-ray Variability in Seyfert Galaxies
• An absorption origin for the X-ray spectral variability of MCG-6-30-15
• Simultaneous X-ray and UV spectroscopy of the Seyfert 1 galaxy NGC 5548.II. Physical conditions in the X-ray absorber
• Physical Diagnostics from a Narrow Fe-Kalpha Emission Line Detected by Chandra in the Seyfert 1 Galaxy NGC 5548
• The Cores of the Fe K Lines in Seyfert I Galaxies Observed by the Chandra High Energy Grating
• Black Holes and Hosts of Active and Quiescent Galaxies: I. The Black Hole-Bulge Relation revisited
• ROSAT monitoring of persistent giant and rapid variability in the narrow-line Seyfert 1 galaxy IRAS 13224-3809
• A Long Look at NGC 3783 with the XMM-Newton Reflection Grating Spectrometers
• Seyfert galaxies in the local Universe (z$\le$ 0.1): the average X-ray spectrum as seen by $BeppoSAX$
• Narrow Components within the Fe Kalpha Profile of NGC 3516: Evidence for the Importance of General Relativistic Effects?
• Modeling of iron K lines: radiative and Auger decay data for Fe II-Fe IX
• Universal spectral shape of high accretion rate AGN
• The XMM-Newton Iron Line Profile of NGC 3783
• X-ray variability and correlations in the two phase disk-corona model for Seyfert galaxies
• Soft X-ray emission lines from a relativistic accretion disk in MCG -6-30-15 and Mrk 766
• X-ray enabled MOCASSIN: a 3D code for photoionized media
• Flux and energy modulation of redshifted iron emission in NGC3516: implications for the black hole mass
• The variable X-ray spectrum of Markarian 766 - I. Principal components analysis
• On the origin of the Fe K-alpha line cores in Active Galactic Nuclei
• Multi-dimensional modelling of X-ray spectra for AGN accretion-disk outflows
• Highly ionized iron absorption lines from outflowing gas in the X-ray spectrum of NGC 1365
• Fe K Emission and Absorption in the XMM-EPIC Spectrum of the Seyfert Galaxy IC 4329a
• X-ray reprocessing in Seyfert Galaxies: simultaneous XMM-Newton/BeppoSAX observations
• Simultaneous Ultraviolet and X-ray Observations of the Seyfert Galaxy NGC 4151. I. Physical Conditions in the X-ray Absorbers
• Complex X-ray Absorption and the Fe Kalpha Profile in NGC 3516
• Fe XXV and Fe XXVI lines from low velocity, photoionised gas in the X-ray spectra of AGN
• A Chandra HETGS Spectral Study of the Iron K Bandpass in MCG-6-30-15: A Narrow View of the Broad Iron Line
• Fe XXV and Fe XXVI Diagnostics of the Black Hole and Accretion Disk in Active Galaxies: Chandra Time-Resolved Spectroscopy of NGC 7314
• Resonant Absorption in the AGN spectra emerging from photoionized gas: differences between steep and flat ionizing continua
• Tracing a Disk Wind in NGC 3516
• Relativistic Iron K Emission and absorption in the Seyfert 1.9 galaxy MCG-5-23-16
• On X-ray variability in narrow line and broad line AGNs
• Dynamical and Spectral Modeling of the Ionized Gas and Nuclear Environment in NGC 3783
• ROSAT HRI Monitoring of Extreme X-ray Variability in the Narrow-Line Quasar PHL 1092
• Relativistic spectral features from X-ray illuminated spots and the measure of the black hole mass in AGN
• Mapping the inner regions of MCG-6-30-15 with XMM-Newton
• A BLR origin for the iron K$\alpha$ line in NGC7213
• X-ray absorption lines suggest matter infalling onto the central black-hole of Mrk 509
• The Variable X-ray Spectrum of Markarian 766 - II. Time-Resolved Spectroscopy
• Recombination spectra of Helium-Like Ions
• Dynamics of Rotating Accretion Flows Irradiated by a Quasar
• An absorption origin for the soft excess in Seyfert 1 AGN
• The mass-energy budget of the ionised outflow in NGC 7469
• A two-component ionized reflection model of MCG--6-30-15
• X-ray spectra transmitted through Compton-thick absorbers
• Ionized iron Kαlines in AGN X-ray spectra
• The shape of the relativistic iron K-alpha line from MCG6--6-30-15 measured with the Chandra HETGS and RXTE
• Black hole mass and accretion rate of active galactic nuclei with double-peaked broad emission lines
• Opacity Variations in the Ionized Absorption in NGC 3783: A Compact Absorber
• The impact of accretion disk winds on the X-ray spectrum of AGN: Part 1 - XSCORT
• Special relativistic effects on the strength of the fluorescent K-alpha iron line from black hole accretion disks
• Occultation Mapping of the Central Engine in the Active Galaxy MCG -6-30-15
• Evidence for Orbital Motion of Material Close to the Central Black Hole of Mrk 766
• The structure and radiation spectra of illuminated accretion disks in AGN. II. Flare/spot model of X-ray variability
• On the Origin of Broad Fe K alpha and Hi H alpha Lines in AGN
• On the deep minimum state in the Seyfert galaxy MCG-6-30-15
• The Density and Location of the X-ray Absorbing Gas in NGC 3516
• Evidence for relativistic features in the X-ray spectrum of Mrk 335
• Can the soft excess in AGN originate from disc reflection?
• The role of absorption and reflection in the soft X-ray excess of Active Galactic Nuclei : 1. Preliminary results
• On the evidence for narrow, relativistically shifted X-ray lines
• The soft X-ray absorption lines of the Seyfert 1 galaxy MCG--6-30-15
• A rapidly variable narrow X-ray iron line in Mkn 841
• What is the origin of the soft excess in AGN?
• Chandra Observations of the Cloverleaf Quasar H 1413+117: A Unique Laboratory for Microlensing Studies of a Lobal Quasar
• The origin of the iron lines in NGC 7213
• Transient Relativistically-Shifted Lines as a Probe of Black Hole Systems
• Resolving the large scale spectral variability of the luminous Seyfert 1 galaxy 1H 0419-577: Evidence for a new emission component and absorption by cold dense matter
• On the X-ray spectra of luminous, inhomogeneous accretion flows
• Suzaku observations of Markarian 335: evidence for a distributed reflector
• Long Term Spectral Variability of Seyfert Galaxies from RXTE Color-Flux Diagrams
• Variable iron-line emission near the black hole of Markarian 766
• The history of the iron K-alpha line profile in the Piccinotti AGN ESO198-G24
• Hard X-ray Variability of AGN
• A softer look at MCG--6-30-15 with XMM-Newton
• Extreme X-ray variability in the luminous quasar PDS 456
• On time-dependent X-ray reflection by photoionized accretion disks: implication for Fe K-alpha line reverberation studies of AGN
• An XMM-Newton observation of the Seyfert 1 galaxy 1H 0419-577 in an extreme low state
• On the inability of Comptonization to produce the broad X-ray iron lines observed in Seyfert nuclei
• A new model for the Warm Absorber in NGC 3783: a single medium in total pressure equilibrium
• Constraints on hot metals in the Vicinity of the Galaxy
• Iron K Features in the Quasar E 1821+643: Evidence for Gravitationally Redshifted Absorption?
• The hard X-ray spectrum of the Seyfert galaxy IRAS 18325-5926: cool corona, reflection from an ionized disk and variable iron K emission
• The XMM-Newton RGS spectrum of the high luminosity Seyfert 1 galaxy Markarian 509
• The highly variable X-ray spectrum of the luminous Seyfert 1 galaxy 1H 0419-577
• Broad redshifted line as a signature of outflow
• Complex Absorption Hides a Type II QSO in IRAS 13197-1627
• Weighing black holes with warm absorbers
• Funnel wall jets and the nature of the soft X-ray excess
• Soft versus Hard X-ray emission in AGN: partial covering and warm plus cold absorber models
• Iron lines from transient and persisting hot spots on AGN accretion disks
• On the variability of the iron line in Mrk 841
• Variation in the primary and reprocessed radiation from an orbiting spot around a black hole
• A new type of photoionized code required for the new era of X-ray spectroscopy
• Rapid N_H Changes in NGC 4151
• Resonant Auger Destruction and Iron K-Alpha Spectra in Compact X-ray Sources
• Modelling the variability of the Fe K alpha line in accreting black holes
• XMM-Newton and Broad Iron Lines
• Emission Line Profiles from Self-Gravitating Thin Disks
• The Additional Line Component within the Iron KαProfile in MCG-6-30-15: Evidence for Blob Ejection?

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• Revisiting the Unified Model of Active Galactic Nuclei
• BAT AGN Spectroscopic Survey - V. X-ray properties of the Swift/BAT 70-month AGN catalog
• Cosmic X-ray Surveys of Distant Active Galaxies: The Demographics, Physics, and Ecology of Growing Supermassive Black Holes
• The Simultaneous Optical-to-X-ray Spectral Energy Distribution of Soft X-ray Selected AGN observed by Swift
• Broad iron L-line and X-ray reverberation in 1H0707-495
• Hot Graphite Dust and the Infrared Spectral Energy Distribution of Active Galactic Nuclei
• The quasar M_bh - M_host relation through Cosmic Time II - Evidence for evolution from z=3 to the present age
• The Cores of the Fe K$\alpha$ Lines in Active Galactic Nuclei: an Extended Chandra High Energy Grating Sample
• X-ray Insights into the Nature of PHL 1811 Analogs and Weak Emission-Line Quasars: Unification with a Geometrically Thick Accretion Disk?
• Warm absorbers in X-rays (WAX), a comprehensive high resolution grating spectral study of a sample of Seyfert galaxies: I. A global view and frequency of occurrence of warm absorbers
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• Multiwavelength campaign on Mrk 509 XII. Broad band spectral analysis
• Multi-dimensional modelling of X-ray spectra for AGN accretion-disk outflows III: application to a hydrodynamical simulation
• Multimessenger astronomy with pulsar timing and X-ray observations of massive black hole binaries
• FERO: Finding Extreme Relativistic Objects. I. Statistics of Relativistic Fe Kalpha lines in Radio-Quiet Type 1 AGN
• Fe-K line probing of material around the AGN central engine with Suzaku
• The Coevolution of Supermassive Black Holes and Massive Galaxies at High Redshift
• A deep X-ray view of the bare AGN Ark120. IV. XMM-Newton and NuSTAR spectra dominated by two temperature (warm, hot) Comptonization processes
• The WISSH Quasars Project III. X-ray properties of hyper-luminous quasars
• X-ray spectral properties of the AGN sample in the northern XMM-XXL field
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• Stratified Magnetically-Driven Accretion-Disk Winds and Their Relations to Jets
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• Acceleration and collimation of relativistic MHD disk winds
• The UV peak in Active Galactic Nuclei : a false continuum from blurred reflection ?
• Multi-dimensional modelling of X-ray spectra for AGN accretion-disk outflows II
• A comprehensive analysis of the hard X-ray spectra of bright Seyfert galaxies
• Testing Quasar Unification: Radiative Transfer in Clumpy Winds
• An intermediate black hole spin in the NLS1 galaxy SWIFT J2127.4+5654: chaotic accretion or spin energy extraction?
• A remarkable long-term light curve, and deep, low-state spectroscopy: Swift & XMM-Newton monitoring of the NLS1 galaxy Mkn 335
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• Revealing the X-ray Variability of AGN with Principal Component Analysis
• C-GOALS II. Chandra Observations of the Lower Luminosity Sample of Nearby Luminous Infrared Galaxies in GOALS
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• Partial dust obscuration in active galactic nuclei as a cause of broad-line profile and lag variability, and apparent accretion disc inhomogeneities
• The narrow Fe K$\alpha$ line and the molecular torus in active galactic nuclei - an IR/X-ray view
• High resolution X-ray spectroscopy of the Seyfert 1 Mrk841: insights into the warm absorber and warm emitter
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• Multiwavelength campaign on Mrk 509. XIII. Testing ionized-reflection models on Mrk 509
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