Towards modeling quasi-periodic oscillations of microquasars with oscillating slender tori

¹ N. Copernicus Astronomical Centre, ul. Rabiańska 8, 87-100 Toruń, Poland
e-mail: fvincent@camk.edu.pl
² Physics Department, Gothenburg University, 41296 Göteborg, Sweden
e-mail: marek.abramowicz@physics.gu.se
³ Physics Department, Warsaw University, ul. Moża 69, 00-681 Warsaw, Poland
e-mail: gmazur@camk.edu.pl
⁴ Chalmers University of Technology, 41296 Gothenburg, Sweden
e-mail: matzjb@yahoo.se
⁵ Physics Department, Silesian University, Opava, Czech Republic
e-mail: terek@volny.cz, pavel.bakala@fpf.slu.cz, sram_eva@centrum.cz

Received: 15 March 2013
Accepted: 29 April 2013

Abstract

Context. One of the often discussed models for high-frequency quasi-periodic oscillations of X-ray binaries is the oscillating torus model, which considers oscillation modes of slender accretion tori.

Aims. Here, we aim at developing this model by considering the observable signature of an optically thick slender accretion torus subject to simple periodic deformations.

Methods. We compute light curves and power spectra of a slender accretion torus subject to simple periodic deformations: vertical or radial translation, rotation, expansion, and shear.

Results. We show that different types of deformations lead to very different Fourier power spectra and therefore could be observationally distinguished.

Conclusions. This work is a first step in a longer term study of the observable characteristics of the oscillating torus model. It gives promising perspectives on the possibility of constraining this model by studying the observed power spectra of quasi-periodic oscillations.