2002/07/29 by T. Gleissner, J. Wilms, K. Pottschmidt +3
Physics and Astronomy · #astro-ph
published as Ph. Durouchoux, Y. Fuchs, and J. Rodriguez (Eds.), New Views on Microquasars, Kolkata: Centre for Space Physics, 2004, p. 46 · 3 pages, 3 figures, Proceedings of the 4th Microquasar Workshop, eds. Ph Durouchoux, Y. Fuchs and J. Rodriguez, published by the Center for Space Physics: Kolkata
arxiv created 2002/07/29 · arxiv updated 2009/12/01
A linear dependence of the amplitude of broadband noise variability on flux for GBHC and AGN has been recently shown by Uttley & McHardy (2001). We present the long term evolution of this rms-flux-relation for Cyg X-1 as monitored from 1998-2002 with RXTE. We confirm the linear relationship in the hard state and analyze the evolution of the correlation for the period of 1996-2002. In the intermediate and the soft state, we find considerable deviations from the otherwise linear relationship. A possible explanation for the rms-flux-relation is a superposition of local mass accretion rate variations.