Hot-spot model for accretion disc variability as random process II. Mathematics of the power-spectrum break frequency

0426304 - ASÚ 2014 RIV FR eng J - Journal Article
Pecháček, Tomáš - Goosmann, R. W. - Karas, Vladimír - Czerny, B. - Dovčiak, Michal
Hot-spot model for accretion disc variability as random process II. Mathematics of the power-spectrum break frequency.
Astronomy & Astrophysics. Roč. 556, August (2013), A77/1-A77/12. ISSN 0004-6361. E-ISSN 1432-0746
R&D Projects: GA ČR(CZ) GC13-00070J
Institutional support: RVO:67985815
Keywords : accretion * black holes
Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics
Impact factor: 4.479, year: 2013

We develop a methodology for determining the regions of the model parameter space that can in principle reproduce a PSD shape with a given number and position of local peaks and breaks of the PSD slope. Given the vast space of possible parameters, it is an important requirement that the method is fast in estimating the PSD shape for a given parameter set of the model. We suggest that our general methodology can be useful for describing non-monotonic PSD profiles (such as the trend seen, on different scales, in exemplary cases of the high-mass X-ray binary Cygnus X-1 and the narrow-line Seyfert galaxy Ark 564). We adopt a model where these power spectra are reproduced as a superposition of several Lorentzians with varying amplitudes in the X-ray-band light curve. Our general approach can help in constraining the model parameters and in determining which parts of the parameter space are accessible under various circumstances
Permanent Link: http://hdl.handle.net/11104/0232055