Bifurcation timescales in power spectra of black hole binaries and ultraluminous X-ray sources
Abstract
For black hole binaries (BHBs) and active galactic nuclei (AGNs), bifurcation timescales (BTs) Δtb exist, below which time-domain power is significantly higher than the corresponding Fourier power. Quasi-periodic oscillations (QPOs) are removed from the Fourier spectra of BHBs. A relationship between BT, black hole mass and bolometric luminosity is derived. Strong anti-correlation between BT and luminosity of Cyg X-1 is found. After removing the QPOs, BTs are also obtained for two ultraluminous X-ray sources (ULXs), M82 X-1 and NGC5408 X-1. The results support that they harbor intermediate mass black holes (IMBHs).
- Publication:
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Science China Physics, Mechanics, and Astronomy
- Pub Date:
- January 2010
- DOI:
- 10.1007/s11433-010-0006-4
- Bibcode:
- 2010SCPMA..53S.177W
- Keywords:
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- black hole binary;
- ultraluminous X-ray source;
- power spectral density;
- data analysis