X-ray spectral and flux variability of the microquasar GRS 1758-258 on timescales from weeks to years

Hirsch M, Pottschmidt K, Smith DM, Bodaghee A, Cadolle Bel M, Grinberg V, Hell N, Krauß F, Kreykenbohm I, Lohfink A, Nowak MA, Rodrigues BH, Soria R, Tomsick JA, Wilms J (2020)

Publication Type: Journal article

Publication year: 2020

Journal

Astronomy & Astrophysics EDP Sciences

Book Volume: 636

Article Number: 1834647

DOI: 10.1051/0004-6361/201834647

Abstract

We present the spectral and timing evolution of the persistent black hole X-ray binary GRS 1758-258 based on almost 12 years of observations using the Rossi X-ray Timing Explorer Proportional Counter Array. While the source was predominantly found in the hard state during this time, it entered the thermally dominated soft state seven times. In the soft state GRS 1758-258 shows a strong decline in flux above 3 keV rather than the pivoting flux around 10 keV more commonly shown by black hole transients. In its 3-20 keV hardness intensity diagram, GRS 1758-258 shows a hysteresis of hard and soft state fluxes typical for transient sources in outburst. The RXTE-PCA and RXTE-ASM long-term light curves do not show any orbital modulations in the range of 2-30 d. However, in the dynamic power spectra significant peaks drift between 18.47 and 18.04 d for the PCA data, while less significant signatures between 19 d and 20 d are seen for the ASM data as well as for the Swift/BAT data. We discuss different models for the hysteresis behavior during state transitions as well as possibilities for the origin of the long term variation in the context of a warped accretion disk.

Authors with CRIS profile

Maria Hirsch Dr.Karl-Remeis-Sternwarte Bamberg, Astronomisches Institut Ingo Kreykenbohm Dr.Karl-Remeis-Sternwarte Bamberg, Astronomisches Institut Jörn Wilms Professur für Astronomie und Astrophysik

Involved external institutions

Montana State University US United States (USA) (US) Brazilian National Institute for Space Research / Instituto Nacional de Pesquisas Espaciais (INPE) BR Brazil (BR) National Astronomical Observatories, Chinese Academy of Sciences / 中国科学院国家天文台 (NAOC) CN China (CN) Georgia College & State University (GCSU) US United States (USA) (US) Washington University US United States (USA) (US) National Aeronautics and Space Administration (NASA) US United States (USA) (US) Santa Cruz Institute for Particle Physics US United States (USA) (US) Rechenzentrum Garching der Max-Planck-Gesellschaft (MPCDF) / Max Planck Computing & Data Facility DE Germany (DE) Eberhard Karls Universität Tübingen DE Germany (DE) Lawrence Livermore National Laboratory US United States (USA) (US) University of Amsterdam NL Netherlands (NL) University of California, Berkeley US United States (USA) (US)

How to cite

APA:

Hirsch, M., Pottschmidt, K., Smith, D.M., Bodaghee, A., Cadolle Bel, M., Grinberg, V.,... Wilms, J. (2020). X-ray spectral and flux variability of the microquasar GRS 1758-258 on timescales from weeks to years. Astronomy & Astrophysics, 636. https://dx.doi.org/10.1051/0004-6361/201834647

MLA:

Hirsch, Maria, et al. "X-ray spectral and flux variability of the microquasar GRS 1758-258 on timescales from weeks to years." Astronomy & Astrophysics 636 (2020).

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