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Short term X-ray rms variability of Cyg X-1

T. Gleissner·J. Wilms·K. Pottschmidt·P. Uttley·M. A. Nowak·R. Staubert
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Abstract

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.

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T. Gleissner, J. Wilms, K. Pottschmidt, P. Uttley, M. A. Nowak, R. Staubert. 2002-07-29. Short term X-ray rms variability of Cyg X-1. https://arxiv.org/abs/astro-ph/0207610

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