Correlated optical, X-ray, and γ-ray flaring activity seen with INTEGRAL during the 2015 outburst of V404 Cygni
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. T...
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| Format: | Journal Article |
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EDP Sciences
2015
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| Online Access: | http://hdl.handle.net/20.500.11937/33365 |
| _version_ | 1848753925897846784 |
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| author | Rodriguez, J. Cadolle Bel, M. Alfonso-Garzón, J. Siegert, T. Zhang, X. Grinberg, V. Savchenko, V. Tomsick, J. Chenevez, J. Clavel, M. Corbel, S. Diehl, R. Domingo, A. Gouiffès, C. Greiner, J. Krause, M. Laurent, P. Loh, A. Markoff, S. Mas-Hesse, J. Miller-Jones, James Russell, D. Wilms, J. |
| author_facet | Rodriguez, J. Cadolle Bel, M. Alfonso-Garzón, J. Siegert, T. Zhang, X. Grinberg, V. Savchenko, V. Tomsick, J. Chenevez, J. Clavel, M. Corbel, S. Diehl, R. Domingo, A. Gouiffès, C. Greiner, J. Krause, M. Laurent, P. Loh, A. Markoff, S. Mas-Hesse, J. Miller-Jones, James Russell, D. Wilms, J. |
| author_sort | Rodriguez, J. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | 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 γ-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 ~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. |
| first_indexed | 2025-11-14T08:32:16Z |
| format | Journal Article |
| id | curtin-20.500.11937-33365 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T08:32:16Z |
| publishDate | 2015 |
| publisher | EDP Sciences |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-333652017-09-13T15:31:40Z Correlated optical, X-ray, and γ-ray flaring activity seen with INTEGRAL during the 2015 outburst of V404 Cygni Rodriguez, J. Cadolle Bel, M. Alfonso-Garzón, J. Siegert, T. Zhang, X. Grinberg, V. Savchenko, V. Tomsick, J. Chenevez, J. Clavel, M. Corbel, S. Diehl, R. Domingo, A. Gouiffès, C. Greiner, J. Krause, M. Laurent, P. Loh, A. Markoff, S. Mas-Hesse, J. Miller-Jones, James Russell, D. Wilms, J. 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 γ-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 ~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. 2015 Journal Article http://hdl.handle.net/20.500.11937/33365 10.1051/0004-6361/201527043 EDP Sciences fulltext |
| spellingShingle | Rodriguez, J. Cadolle Bel, M. Alfonso-Garzón, J. Siegert, T. Zhang, X. Grinberg, V. Savchenko, V. Tomsick, J. Chenevez, J. Clavel, M. Corbel, S. Diehl, R. Domingo, A. Gouiffès, C. Greiner, J. Krause, M. Laurent, P. Loh, A. Markoff, S. Mas-Hesse, J. Miller-Jones, James Russell, D. Wilms, J. Correlated optical, X-ray, and γ-ray flaring activity seen with INTEGRAL during the 2015 outburst of V404 Cygni |
| title | Correlated optical, X-ray, and γ-ray flaring activity seen with INTEGRAL during the 2015 outburst of V404 Cygni |
| title_full | Correlated optical, X-ray, and γ-ray flaring activity seen with INTEGRAL during the 2015 outburst of V404 Cygni |
| title_fullStr | Correlated optical, X-ray, and γ-ray flaring activity seen with INTEGRAL during the 2015 outburst of V404 Cygni |
| title_full_unstemmed | Correlated optical, X-ray, and γ-ray flaring activity seen with INTEGRAL during the 2015 outburst of V404 Cygni |
| title_short | Correlated optical, X-ray, and γ-ray flaring activity seen with INTEGRAL during the 2015 outburst of V404 Cygni |
| title_sort | correlated optical, x-ray, and γ-ray flaring activity seen with integral during the 2015 outburst of v404 cygni |
| url | http://hdl.handle.net/20.500.11937/33365 |