An underlying clock in the extreme flip-flop state transitions of the black hole transient Swift J1658.2-4242
| Autor: | Gabriele Ponti, Tomaso Belloni, Kirpal Nandra, Teo Muñoz-Darias, James Miller-Jones, Haiwu Pan, Thomas D. Russell, F. M. Vincentelli, Chichuan Jin, Pavan Vynatheya, David Bogensberger |
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| Přispěvatelé: | API Other Research (FNWI) |
| Rok vydání: | 2020 |
| Předmět: |
High Energy Astrophysical Phenomena (astro-ph.HE)
Physics Swift 010308 nuclear & particles physics Scattering Astrophysics::High Energy Astrophysical Phenomena FOS: Physical sciences Binary number Astronomy and Astrophysics Astrophysics Light curve 01 natural sciences Accretion (astrophysics) Spectral line Black hole 13. Climate action Space and Planetary Science 0103 physical sciences Halo Astrophysics - High Energy Astrophysical Phenomena 010303 astronomy & astrophysics computer computer.programming_language |
| Zdroj: | Astronomy & Astrophysics Astronomy & Astrophysics, 641:A101. EDP Sciences |
| ISSN: | 0004-6361 |
| DOI: | 10.1051/0004-6361/202037657 |
| Popis: | Aims: Flip-flops are top-hat-like X-ray flux variations which occur in some transient accreting black hole binary systems and feature simultaneous changes in the spectral hardness and the Power Density Spectrum (PDS). They occur at a crucial time in the evolution of these systems, when the accretion disk emission starts to dominate over coronal emission. Flip-flops have only rarely been observed and are poorly understood. Methods: We detect 15 flip-flops in the 2018 outburst of Swift J1658.2-4242, in observations by XMM-Newton, NuSTAR, Astrosat, Swift, Insight-HXMT, INTEGRAL, and ATCA. We analyse their light curves, search for periodicities, compute their PDS, and fit their X-ray spectra, to investigate the source behaviour during flip-flop transitions, and how the interval featuring flip-flops differs from the rest of the outburst. Results: The flip-flops of Swift J1658.2-4242 are of an extreme variety, exhibiting flux differences of up to 77% within ~100s, much larger than has been seen so far. We observe radical changes in the PDS simultaneous with the sharp flux variations, featuring transitions between the Quasi-Periodic Oscillation types C and A, which have never been observed before. Changes to the PDS are delayed, but more rapid than changes in the light curve. Flip-flops occur in two intervals, separated by two weeks in which these phenomena were not seen. Transitions between the two flip-flop states occurred at random integer multiples of a fundamental period, of 2.761ks in the first interval, and 2.61ks in the second. Spectral analysis reveals the high and low flux flip-flop states to be similar, but distinct from intervals lacking flip-flops. A change in the inner temperature of the accretion disk is responsible for most of the flux difference in the flip-flops. We highlight the importance of correcting for the influence of the dust scattering halo on the X-ray spectra. 30 pages, 28 figures, accepted for publication in Astronomy & Astrophysics |
| Databáze: | OpenAIRE |
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