Role of emission angular directionality in spin determination of accreting black holes with a broad iron line

0332636 - ASÚ 2010 RIV FR eng J - Journal Article
Svoboda, Jiří - Dovčiak, Michal - Goosmann, René - Karas, Vladimír
Role of emission angular directionality in spin determination of accreting black holes with a broad iron line.
Astronomy & Astrophysics. Roč. 507, č. 1 (2009), s. 1-17. ISSN 0004-6361. E-ISSN 1432-0746
R&D Projects: GA ČR GA205/07/0052; GA ČR GD205/09/H033; GA MŠMT(CZ) LC06014; GA AV ČR IAA300030510; GA MŠMT ME09036
Grant - others:EU(XE) ESA-PECS project No. 98040
Institutional research plan: CEZ:AV0Z10030501
Keywords : accretion disc * black hole physics * active galaxies
Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics
Impact factor: 4.179, year: 2009

We discuss the method to determine the spin of black holes by employing the broad relativistic iron line profiles in the X-ray domain. The precision of the spectral fitting procedure could be compromised by an inappropriate account for the angular distribution of the disc emission. Often a unique profile is assumed, invariable over the entire range of radii in the disc and energy in the spectral band. We study how sensitive the spin determination is to the assumptions about the intrinsic angular distribution of the emitted photons. Based on the radiation transfer computations, we produced a new extension to the KY software package for X-ray spectra fitting of relativistic accretion disc models. We found that, from the commonly used simple profiles, the isotropic distribution of the angular emissivity reproduces our model data to the best precision.
Permanent Link: http://hdl.handle.net/11104/0177839