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

Grinberg, V. and Hell, N. and Wilms, J. and Rodriguez, J. and Pottschmidt, K. and Nowak, M. A. and Böck, M. and Bodaghee, A. and Cadolle Bel, M. and Fürst, F. and Hanke, M. and Kühnel, M. and Laurent, P. and Markoff, S. B. and Markowitz, A. and Marcu, D. M. and Pooley, G. G. and Popp, A. and Rothschild, R. E. and Tomsick, J. A. (2012) Cygnus X-1: shedding light on the spectral variability of a black hole. In: An INTEGRAL view of the high-energy sky (the first 10 years) - 9th INTEGRAL Workshop and celebration of the 10th anniversary of the launch (INTEGRAL 2012). Proceedings of Science. No.176. SISSA , Trieste, Italy, Art. No. 050.

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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.

Item Type:Book Section
Related URLs:
URLURL TypeDescription Section
Grinberg, V.0000-0003-2538-0188
Wilms, J.0000-0003-2065-5410
Pottschmidt, K.0000-0002-4656-6881
Nowak, M. A.0000-0001-6923-1315
Bodaghee, A.0000-0002-7315-3732
Fürst, F.0000-0003-0388-0560
Markoff, S. B.0000-0001-9564-0876
Tomsick, J. A.0000-0001-5506-9855
Additional Information:Copyright owned by the author(s) under the term of the Creative Commons Attribution-NonCommercial-ShareAlike. This work has been partially funded by the Bundesministerium für Wirtschaft und Technologie under Deutsches Zentrum für Luft- und Raumfahrt Grants 50 OR 1007 and 50 OR 1113 and by the European Commission through ITN 215212 “Black Hole Universe”, was partially completed by LLNL under Contract DE-AC52-07NA27344. K.P. and D.M.M. acknowledge support from NASA grant NNX09AT28G for INTEGRAL’s Cycle 7 Guest Observer Programme. The data analysis presented in this work was performed with ISIS 1.6.2 [5]. We thank John E. Davis for the development of the slxfig module used to prepare all figures in this work.
Group:Space Radiation Laboratory
Funding AgencyGrant Number
Bundesministerium für Wirtschaft und Technologie (BMWi)UNSPECIFIED
Deutsches Zentrum für Luft-und Raumfahrt (DLR)50 OR 1007
Deutsches Zentrum für Luft-und Raumfahrt (DLR)50 OR 1113
European CommissionITN 215212
Department of Energy (DOE)DE-AC52-07NA27344
Series Name:Proceedings of Science
Issue or Number:176
Record Number:CaltechAUTHORS:20180828-122925125
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:89235
Deposited By: George Porter
Deposited On:30 Aug 2018 14:33
Last Modified:16 Nov 2021 00:33

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