Spectral and timing evolution of the bright failed outburst of the transient black hole Swift J174510.8-262411

Del Santo M, Belloni TM, Tomsick JA, Sbarufatti B, Bel MC, Casella P, Castro-Tirado A, Corbel S, Grinberg V, Homan J, Kalemci E, Motta SE, Munoz-Darias T, Pottschmidt K, Rodriguez J, Wilms J (2016)

Publication Status: Published

Publication Type: Journal article, Original article

Publication year: 2016

Journal

Monthly Notices of the Royal Astronomical Society Oxford University Press

Publisher: Oxford University Press

Book Volume: 456

Pages Range: 3585-3595

Journal Issue: 4

DOI: 10.1093/mnras/stv2901

Abstract

We studied time variability and spectral evolution of the Galactic black hole transient Swift J174510.8-262411 during the first phase of its outburst. INTEGRAL and Swift observations collected from 2012 September 16 until October 30 have been used. The total squared fractional rms values did not drop below 5 per cent and quasi-periodic oscillations (QPOs), when present, were type-C, indicating that the source never made the transition to the soft-intermediate state. Even though the source was very bright (up to 1 Crab in hard X-rays), it showed a so called failed outburst as it never reached the soft state. XRT and IBIS broad-band spectra, well represented by a hybrid thermal/non-thermal Comptonization model, showed physical parameters characteristic of the hard and intermediate states. In particular, the derived temperature of the geometrically thin disc blackbody was about 0.6 keV at maximum. We found a clear decline of the optical depth of the corona electrons (close to values of 0.1), as well as of the total compactness ratio l/l. The hard-to-hard/intermediate state spectral transition is mainly driven by the increase in the soft photon flux in the corona, rather than small variations of the electron heating. This, associated with the increasing of the disc temperature, is consistent with a disc moving towards the compact object scenario, i.e. the truncated-disc model. Moreover, this scenario is consistent with the decreasing fractional squared rms and increasing of the noise and QPO frequency. In our final group of observations, we found that the contribution from the non-thermal Comptonization to the total power supplied to the plasma is 0.59 and that the thermal electrons cool to kT < 26 keV.

Authors with CRIS profile

Jörn Wilms Professur für Astronomie und Astrophysik

Involved external institutions

Rechenzentrum Garching der Max-Planck-Gesellschaft (MPCDF) / Max Planck Computing & Data Facility DE Germany (DE) University of Oxford GB United Kingdom (GB) Sabanci University TR Turkey (TR) University of Maryland, Baltimore County US United States (USA) (US) University of California, Berkeley US United States (USA) (US) University of Paris 7 - Denis Diderot / Université Paris VII Denis Diderot FR France (FR) Spanish National Research Council / Consejo Superior de Investigaciones Científicas (CSIC) ES Spain (ES) National Institute for Astrophysics / Istituto Nazionale Astrofisica (INAF) IT Italy (IT) Instituto de Astrofísica de Canarias (IAC) ES Spain (ES) Massachusetts Institute of Technology (MIT) US United States (USA) (US) Institute of Space Astrophysics and Cosmic Physics / Palermo Istituto di Astrofisica Spaziale e Fisica Cosmica (IASF) IT Italy (IT)

How to cite

APA:

Del Santo, M., Belloni, T.M., Tomsick, J.A., Sbarufatti, B., Bel, M.C., Casella, P.,... Wilms, J. (2016). Spectral and timing evolution of the bright failed outburst of the transient black hole Swift J174510.8-262411. Monthly Notices of the Royal Astronomical Society, 456(4), 3585-3595. https://dx.doi.org/10.1093/mnras/stv2901

MLA:

Del Santo, Melania, et al. "Spectral and timing evolution of the bright failed outburst of the transient black hole Swift J174510.8-262411." Monthly Notices of the Royal Astronomical Society 456.4 (2016): 3585-3595.

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