Correlated optical, X- ray, and gamma- ray flaring activity seen with INTEGRAL during the 2015 outburst of V404 Cygni

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Details zur Publikation

Autorinnen und Autoren: Rodriguez J, Bel MC, Alfonso-Garzon J, Siegert T, Zhang XL, Grinberg V, Savchenko V, Tomsick JA, Chenevez J, Clavel M, Corbel S, Diehl R, Domingo A, Gouiffes C, Greiner J, Krause MGH, Laurent P, Loh A, Markoff S, Mas-Hesse JM, Miller-Jones JCA, Russell DM, Wilms J
Zeitschrift: Astronomy & Astrophysics
Verlag: EDP Sciences
Jahr der Veröffentlichung: 2015
Band: 581
ISSN: 1432-0746


After 25 years of quiescence, the microquasar V404 Cyg entered a new period of activity in June 2015. This X-ray source is known to undergo extremely bright and variable outbursts seen at all wavelengths. It is therefore an object of prime interest to understand the accretion-ejection connections. These can, however, only be probed through simultaneous observations at several wavelengths. We made use of the INTEGRAL instruments to obtain long, almost uninterrupted observations from 2015 June 20, 15: 50 UTC to June 25, 4: 05 UTC, from the optical V band up to the soft gamma-rays. V404 Cyg was extremely variable in all bands, with the detection of 18 flares with fluxes exceeding 6 Crab (20-40 keV) within three days. The flare recurrence can be as short as similar to 20 min from peak to peak. A model-independent analysis shows that the >6 Crab flares have a hard spectrum. A simple 10-400 keV spectral analysis of the off-flare and flare periods shows that the variation in intensity is likely to be only due to variations of a cut-off power-law component. The optical flares seem to be at least of two different types: one occurring in simultaneity with the X-ray flares, the other showing a delay greater than 10 min. The former could be associated with X-ray reprocessing by either an accretion disk or the companion star. We suggest that the latter are associated with plasma ejections that have also been seen in radio.

FAU-Autorinnen und Autoren / FAU-Herausgeberinnen und Herausgeber

Wilms, Jörn Prof. Dr.
Professur für Astronomie und Astrophysik

Einrichtungen weiterer Autorinnen und Autoren

Curtin University
Massachusetts Institute of Technology (MIT)
Max-Planck-Institut für extraterrestrische Physik (MPE) / Max Planck Institute for Extraterrestrial Physics
New York University Abu Dhabi (NYU Abu Dhabi)
Rechenzentrum Garching der Max-Planck-Gesellschaft (MPCDF) / Max Planck Computing & Data Facility
Spanish National Research Council / Consejo Superior de Investigaciones Científicas (CSIC)
Technical University of Denmark / Danmarks Tekniske Universitet (DTU)
University of Amsterdam
University of California, Berkeley
University of Paris 7 - Denis Diderot / Université Paris VII Denis Diderot


Rodriguez, J., Bel, M.C., Alfonso-Garzon, J., Siegert, T., Zhang, X.-L., Grinberg, V.,... Wilms, J. (2015). Correlated optical, X- ray, and gamma- ray flaring activity seen with INTEGRAL during the 2015 outburst of V404 Cygni. Astronomy & Astrophysics, 581.

Rodriguez, J., et al. "Correlated optical, X- ray, and gamma- ray flaring activity seen with INTEGRAL during the 2015 outburst of V404 Cygni." Astronomy & Astrophysics 581 (2015).


Zuletzt aktualisiert 2018-11-08 um 02:43