Cygnus X-1: shedding light on the spectral variability of a black hole

2013/03/11 by Grinberg, V., Hell, N., Wilms, J. +17
#FOS: Physical sciences #High Energy Astrophysical Phenomena (astro-ph.HE)

paper · doi:10.48550/arxiv.1303.2678

Abstract

The knowledge of the spectral state of a black hole is essential for the interpretation of data from black holes in terms of their emission models. Based on pointed observations of Cyg X-1 with the Rossi X-ray timing Explorer (RXTE) that are used to classify simultaneous RXTE-ASM observations, we develop a scheme based on RXTE -ASM colors and count rates that can be used to classify all observations of this canonical black hole that were performed between 1996 and 2011. We show that a simple count rate criterion, as used previously, leads to a significantly higher fraction of misclassified observations. This scheme enables us to classify single INTEGRAL-IBIS science windows and to obtain summed spectra for the soft, intermediate and hard state with low contamination by other states.

Related

• Correlated Spectral and Recurrence Variations of Cygnus X-1
• RXTE Observations of Cygnus X-1: Broad-Band Spectra and High-Resolution Timing
• High energy spectral study of the black hole Cygnus X-1 with INTEGRAL
• The broadband spectrum of Cygnus X-1
• Observations of Cygnus X-1 during the two spectral states with the Indian X-ray Astronomy Experiment (IXAE)