Broadband X-Ray Spectral and Timing Analyses of the Black Hole Binary Candidate Swift J1658.2-4242: Rapid Flux Variation and the Turn-on of a Transient QPO

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Details zur Publikation

Autorinnen und Autoren: Xu Y, Harrison FA, Tomsick JA, Barret D, Gandhi P, Garcia J, Miller JM, Uttley P, Walton DJ
Zeitschrift: Astrophysical Journal
Jahr der Veröffentlichung: 2019
Band: 879
Heftnummer: 2
ISSN: 0004-637X
eISSN: 1538-4357


Abstract

We report results from joint Nuclear Spectroscopic Telescope Array, Swift, and XMM-Newton observations of the newly discovered black hole X-ray binary candidate Swift J1658.2-4242 in the intermediate state. We observe a peculiar event in this source, with its X-ray flux rapidly decreasing by similar to 45% in similar to 40 s, accompanied by only subtle changes in the shape of the broadband X-ray spectrum. In addition, we find a sudden turn-on of a transient quasiperiodic oscillation (QPO) with a frequency of 6-7 Hz around the time of the flux change, and the total fractional rms amplitude of the power spectrum increases from similar to 2% to similar to 10%. The X-ray spectral and timing analyses indicate that the flux decrease is driven by intrinsic changes in the accretion flow around the black hole, rather than intervening material along the line of sight. In addition, we do not significantly detect any relativistic disk reflection component, indicating it is much weaker than previously observed while the source was in the bright hard state. We propose accretion disk instabilities triggered at a large disk radius as the origin of the fast transition in spectral and timing properties, and discuss possible causes of the unusual properties observed in Swift J1658.2-4242. The prompt flux variation detected along with the emergence of a QPO makes the event an interesting case for investigating QPO mechanisms in black hole X-ray binaries.


FAU-Autorinnen und Autoren / FAU-Herausgeberinnen und Herausgeber

Garcia, Javier Dr.
Dr.Karl-Remeis-Sternwarte Bamberg, Astronomisches Institut


Einrichtungen weiterer Autorinnen und Autoren

California Institute of Technology (Caltech)
University of Amsterdam
University of California, Berkeley
University of Cambridge
University of Michigan
University of Southampton
University of Toulouse


Zitierweisen

APA:
Xu, Y., Harrison, F.A., Tomsick, J.A., Barret, D., Gandhi, P., Garcia, J.,... Walton, D.J. (2019). Broadband X-Ray Spectral and Timing Analyses of the Black Hole Binary Candidate Swift J1658.2-4242: Rapid Flux Variation and the Turn-on of a Transient QPO. Astrophysical Journal, 879(2). https://dx.doi.org/10.3847/1538-4357/ab24bf

MLA:
Xu, Yanjun, et al. "Broadband X-Ray Spectral and Timing Analyses of the Black Hole Binary Candidate Swift J1658.2-4242: Rapid Flux Variation and the Turn-on of a Transient QPO." Astrophysical Journal 879.2 (2019).

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Zuletzt aktualisiert 2019-23-08 um 08:33