An X-ray variable absorber within the broad line region in Fairall 51

0452143 - ASÚ 2016 RIV FR eng J - Journal Article
Svoboda, Jiří - Beuchert, T. - Guainazzi, M. - Longinotti, A. L. - Piconcelli, E. - Wilms, J.
An X-ray variable absorber within the broad line region in Fairall 51.
Astronomy & Astrophysics. Roč. 578, June (2015), A96/1-A96/11. ISSN 0004-6361. E-ISSN 1432-0746
R&D Projects: GA ČR(CZ) GP14-20970P
Institutional support: RVO:67985815
Keywords : active galactic nuclei * supermassive black-holes * warped accretion discs
OECD category: Astronomy (including astrophysics,space science)
Impact factor: 5.185, year: 2015

In our research, we observed Fairall 51 with the X-ray satellite Suzaku in order to constrain a characteristic time scale of its variability. We found that the 0.5-50 keV broadband X-ray spectra are dominated by a primary power-law emission (with the photon index similar to 2). This emission is affected by at least three absorbers with different ionisations (log xi approximate to 1-4). The spectrum is shaped further by a reprocessed emission, possibly coming from two regions, the accretion disc and a more distant scattering region. The accretion disc emission is smeared by the relativistic effects, from which we measured the spin of the black hole as a approximate to 0.8 +/- 0.2. We found that most of the spectral variability can be attributed to the least ionised absorber whose column density changed by a factor of two between the first (highest-flux) and the last (lowest-flux) observation. A week-long scale of the variability indicates that the absorber is located at the distance approximate to 0.05 pc from the centre, i.e., in the broad line region.
Permanent Link: http://hdl.handle.net/11104/0253169