The flare model for X-ray variability of NGC 4258

0359783 - ASÚ 2012 RIV FR eng J - Journal Article
Trzesniewski, T. - Czerny, B. - Karas, Vladimír - Pecháček, Tomáš - Dovčiak, Michal - Goosmann, R. W. - Nikolajuk, M.
The flare model for X-ray variability of NGC 4258.
Astronomy & Astrophysics. Roč. 530, June (2011), A136/1-A136/6. ISSN 0004-6361. E-ISSN 1432-0746
R&D Projects: GA ČR GA205/07/0052; GA MŠMT ME09036; GA ČR GA202/09/0772; GA ČR GP205/09/P468
Institutional research plan: CEZ:AV0Z10030501
Keywords : accretion disks * active galaxies * X-rays
Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics
Impact factor: 4.587, year: 2011

We study the variability mechanism of active galactic nuclei (AGN) within the framework of the flare model. To this end we examine the case of Seyfert/LINER galaxy NGC 4258, which is observed at high inclination angle and exhibits rapid fluctuations of the X-ray light curve. We construct a model light curve based on the assumption of magnetic flares localized in the equatorial plane. We calculate the level of variability as a function of the inclination. Highly inclined sources such as this one are particularly suitable to test the flare model because the effects of orbital motion, Doppler boosting and light bending are all expected to have maximum when the accretion disk is seen almost edge-on. The model is consistent with the NGC 4258 variability, where the obscuring material is thought to be localized mainly towards the equatorial plane.
Permanent Link: http://hdl.handle.net/11104/0197496