QPO and LFN in the power spectrum of rapid variability for the X-ray nova SWIFT J174510.8-262411
Abstract
Results of the study of the X-ray nova SWIFT J174510.8-262411 by the INTEGRAL, SWIFT, and VLA observatories in September-October 2012 at the early outburst phase are presented. Attention is focused on analyzing the power spectrum of X-ray flux fluctuations of the source in which a powerful quasi-periodic oscillation (QPO) peak has been detected. The evolution of the QPO peak parameters with time has been traced; a correlation between the QPO frequency, low-frequency noise (LFN) parameters, X-ray and radio fluxes, and fractional polarization of radio emission has been revealed. The fractal properties of the source's light curves in the standard X-ray band (<10 keV) are shown to change with QPO peak frequency. In the hard X-ray band (20-80 keV), the source's light curves have no fractal properties, despite the larger QPO and LFN amplitude than that in the standard X-ray band. The observational results can be explained by assuming that the source's X-ray emission is formed in a hot plasma cloud surrounding a black hole, while the QPOs are produced at its boundary, at the place of contact with the accretion disk; their frequency reflects the Keplerian rotation of matter at the corresponding radius.
- Publication:
-
Astronomy Letters
- Pub Date:
- October 2015
- DOI:
- 10.1134/S1063773715100060
- Bibcode:
- 2015AstL...41..549P
- Keywords:
-
- X-ray sources;
- transients;
- black holes;
- spectral states;
- quasi-periodic oscillations;
- disk accretion