On the origin of the Fe K-alpha line cores in Active Galactic Nuclei

Abstract

X-ray observations with Chandra and XMM-Newton have shown that there are relatively narrow cores to the iron K-alpha emission lines in active galactic nuclei (AGN). Plausible origins for this core emission include the outer regions of an accretion disk, a pc-scale molecular torus, and the optical broad-line region (BLR). Using data from the literature it is shown that no correlation exists between the Fe K-alpha core width and the BLR (specifically H-beta) line width. This shows that in general the iron K-alpha core emission does not arise from the BLR. There is a similar lack of correlation between the width of the Fe K-alpha core and black hole mass. The average K-alpha width is about a factor of two lower than the H-beta width. It therefore seems likely that in many cases the narrow core arises in the torus. There is a very wide range of observed Fe K-alpha core widths, however, and this argues for multiple origins. The simplest explanation for the observed line profiles in AGN is that they are due to a mixing of very narrow emission from the inner edge of the torus, and broadened emission from the accretion disk, in varying proportions from object-to-object.

5 pages, 2 figures, accepted for publication in MNRAS Letters

Cited by in corpus (41)

• An XMM-Newton survey of broad iron lines in Seyfert galaxies
• BAT AGN Spectroscopic Survey - V. X-ray properties of the Swift/BAT 70-month AGN catalog
• Relativistic X-ray Lines from the Inner Accretion Disks Around Black Holes
• X-ray Absorption and Reflection in Active Galactic Nuclei
• Seyfert galaxies in the local Universe (z$\le$ 0.1): the average X-ray spectrum as seen by $BeppoSAX$
• On the Iwasawa-Taniguchi effect of radio-quiet AGN
• A BLR origin for the iron K$\alpha$ line in NGC7213
• NLS1 galaxies and estimation of their central black hole masses from the X-ray excess variance method
• Does the AGN Unified Model Evolve with Redshift? Utilizing the X-ray Background to Predict the Mid-Infrared Emission of AGN
• A comparison of hard X-ray photon indices and iron \ka emission lines in X-ray luminous narrow- and broad-line Seyfert 1 galaxies
• XMM-Newton and Suzaku analysis of the Fe K complex in the Seyfert 1 galaxy Mrk 509
• A New Black Hole Mass Estimate for Obscured Active Galactic Nuclei
• An X-ray look at the Seyfert 1 Galaxy Mrk 590: XMM-Newton and Chandra reveal complexity in circumnuclear gas
• Localizing narrow Fe K$\alpha$ emission within bright AGN
• A redshifted Fe K$\alpha$ line from the unusual gamma-ray source PMN J1603-4904
• Multiwavelength campaign on Mrk 509 XV. A global modeling of the broad emission lines in the Optical, UV and X-ray bands
• No Signatures of Black-Hole Spin in the X-ray Spectrum of the Seyfert 1 Galaxy Fairall 9
• Relativistic accretion disk reflection in AGN X-ray spectra at z=0.5--4: a study of four \textit{Chandra} deep fields
• Probing Nuclear and Circumnuclear Properties of NGC 6300 using X-ray Observations
• Properties of the Obscuring Torus in NGC 1052 from Multi-epoch Broadband X-ray Spectroscopy
• Relativistic reflection in the average X-ray spectrum of AGN in the Véron-Cetty & Véron catalogue
• Detection of blueshifted emission and absorption and a relativistic Iron line in the X-ray spectrum of ESO 323-G077
• Origin of X-rays in the low state of the FSRQ 3C 273: Evidence of inverse Compton emission
• NGC 6240 Supermassive Black Hole Binary dynamical evolution based on Chandra data
• Anisotropic radiation from accretion disc-coronae in active galactic nuclei
• X-ray properties of the quasar HE0450-2958
• 2MASX J00423991+3017515: An offset active galactic nucleus in an interacting system
• Still alive and kicking: A significant outburst in changing-look AGN Mrk 1018
• A systematic study of photoionized emission and warm absorption signatures of the NLS1 Mrk 335
• Relativistic iron K alpha line detection in the Suzaku spectra of IC 4329A
• XMM-Newton and NuSTAR Observations of an Optically Quiescent Quasar
• Are Compton-thin AGNs Globally Compton Thin?
• Probing the Extent of Fe K$\alpha$ Emission in Nearby Active Galactic Nuclei using Multi-Order Analysis of Chandra High Energy Transmission Grating Data
• Detection of the Fe K lines from the binary AGN in 4C+37.11
• XMM-Newton --NuSTAR monitoring campaign of the Seyfert 1 galaxy IC 4329A
• Inferring Compton-thick AGN candidates at z>2 with Chandra using the >8 keV restframe spectral curvature
• A Systematic Study of the Short-Term X-ray Variability of Seyfert Galaxies I. Diversity of the X-ray Rms Spectra
• Detection of Asymmetry in the Narrow Fe K$\alpha$ Emission Line in MCG-5-23-16 with Chandra
• Active Galactic Nuclei and their demography through cosmic time
• The onset of General Relativity: Gravitationally redshifted emission lines
• Selection of Compton-thick AGN from a hard photometric sample using XMM-Newton observations