Multiwavelength observations of the black hole transient Swift J1745-26 during the outburst decay

Kalemci E, Arabaci MO, Guver T, Russell DM, Tomsick JA, Wilms J, Weidenspointner G, Kuulkers E, Falanga M, Dincer T, Drave S, Belloni T, Coriat M, Lewis F, Munoz-Darias T (2014)

Publication Status: Published

Publication Type: Journal article

Publication year: 2014

Journal

Monthly Notices of the Royal Astronomical Society Oxford University Press

Publisher: OXFORD UNIV PRESS

Book Volume: 445

Pages Range: 1288-1298

Journal Issue: 2

DOI: 10.1093/mnras/stu1851

Abstract

We characterized the broad-band X-ray spectra of Swift J1745-26 during the decay of the 2013 outburst using INTEGRAL ISGRI, JEM-X and Swift XRT. The X-ray evolution is compared to the evolution in optical and radio. We fit the X-ray spectra with phenomenological and Comptonization models. We discuss possible scenarios for the physical origin of an similar to 50 d flare observed both in optical and X-rays similar to 170 d after the peak of the outburst. We conclude that it is a result of enhanced mass accretion in response to an earlier heating event. We characterized the evolution in the hard-X-ray band and showed that for the joint ISGRI-XRT fits, the e-folding energy decreased from 350 to 130 keV, while the energy where the exponential cut-off starts increased from 75 to 112 keV as the decay progressed. We investigated the claim that high-energy cut-offs disappear with the compact jet turning on during outburst decays, and showed that spectra taken with HEXTE on RXTE provide insufficient quality to characterize cut-offs during the decay for typical hard-X-ray fluxes. Long INTEGRAL monitoring observations are required to understand the relation between the compact jet formation and hard-X-ray behaviour. We found that for the entire decay (including the flare), the X-ray spectra are consistent with thermal Comptonization, but a jet synchrotron origin cannot be ruled out.

Authors with CRIS profile

Jörn Wilms Professur für Astronomie und Astrophysik

Involved external institutions

Sabanci University TR Turkey (TR) University of Oxford GB United Kingdom (GB) University of South Wales GB United Kingdom (GB) University of Cape Town (UCT) ZA South Africa (ZA) National Institute for Astrophysics / Istituto Nazionale Astrofisica (INAF) IT Italy (IT) University of Southampton GB United Kingdom (GB) International Space Science Institute (ISSI) CH Switzerland (CH) European Space Agency (ESA) FR France (FR) European X-Ray Free-Electron Laser Facility GmbH DE Germany (DE) University of California, Berkeley US United States (USA) (US) New York University Abu Dhabi (NYU Abu Dhabi) AE United Arab Emirates (AE) Istanbul University / İstanbul Üniversitesi TR Turkey (TR) Middle East Technical University (METU) / Orta Doğu Teknik Üniversitesi TR Turkey (TR)

How to cite

APA:

Kalemci, E., Arabaci, M.O., Guver, T., Russell, D.M., Tomsick, J.A., Wilms, J.,... Munoz-Darias, T. (2014). Multiwavelength observations of the black hole transient Swift J1745-26 during the outburst decay. Monthly Notices of the Royal Astronomical Society, 445(2), 1288-1298. https://dx.doi.org/10.1093/mnras/stu1851

MLA:

Kalemci, E., et al. "Multiwavelength observations of the black hole transient Swift J1745-26 during the outburst decay." Monthly Notices of the Royal Astronomical Society 445.2 (2014): 1288-1298.

BibTeX: Download