Discovery Of Transient Iron Fluorescence In The Bare Seyfert Ark 120
Date Issued
2016
Author(s)
Abstract
We present the results from an X-ray observational campaign on the bare Seyfert galaxy Ark 120 jointly carried out with XMM- Newton, Chandra, and NuSTAR. The favourable line of sight to this source, devoid of any significant absorbing material, provides an incomparably clean view to the nuclear regions of an AGN, down to the the immediate surroundings of the radiatively efficient, accreting supermassive black hole. Here we focus on the nature, properties, and variability of the emission-line complex due to iron fluorescence detected in the 6-7 keV band. The narrow K-alpha feature from neutral iron at 6.4 keV is resolved by Chandra/HETG to a width of 5000 km/s, consistent with origin from the optical broad-line region. However, excess components are seen on both sides of this core. The excess emission map computed over the 7.5 days of XMM-Newton monitoring and the following, time-resolved spectral analysis show that both the red and blue features are highly variable on timescales of 10-15 hours. Any explanation (orbiting hotspots, coronal clumps, disc instabilities) requires a highly dynamic, inhomogeneous disc/coronal system. These observations thus prove the unique potential of a bare source like Ark 120 to better understand the physics of the accretion disc/X-ray corona system in AGN....
Coverage
Active Galactic Nuclei 12: A Multi-Messenger Perspective (AGN12)
Conferenece
Active Galactic Nuclei 12: A Multi-Messenger Perspective (AGN12)
Conferenece place
Napoli, Italy
Conferenece date
26-29 September 2016
Ads BibCode
2016agnt.confE..34N
Rights
open.access
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Name
agn12_nardini_talk.pdf
Description
slides
Size
1.99 MB
Format
Adobe PDF
Checksum (MD5)
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