The peculiar 2011 outburst of the black hole candidate IGR J17091−3624, a GRS 1915+105-like source?
Article first published online: 5 APR 2012
© 2012 The Authors Monthly Notices of the Royal Astronomical Society © 2012 RAS
Monthly Notices of the Royal Astronomical Society
Volume 422, Issue 4, pages 3130–3141, June 2012
How to Cite
Capitanio, F., Del Santo, M., Bozzo, E., Ferrigno, C., De Cesare, G. and Paizis, A. (2012), The peculiar 2011 outburst of the black hole candidate IGR J17091−3624, a GRS 1915+105-like source?. Monthly Notices of the Royal Astronomical Society, 422: 3130–3141. doi: 10.1111/j.1365-2966.2012.20834.x
- Issue published online: 21 MAY 2012
- Article first published online: 5 APR 2012
- Accepted 2012 February 28. Received 2012 February 24; in original form 2011 October 19
- accretion, accretion discs;
- methods: observational;
- X-rays: binaries
We report on the long-term monitoring campaign of the black hole candidate IGR J17091−3624 performed with INTEGRAL and Swift during the peculiar outburst started on 2011 January. We have studied the two-month spectral evolution of the source in detail. Unlike the previous outbursts, the initial transition from the hard to the soft state in 2011 was not followed by the standard spectral evolution expected for a transient black hole binary. IGR J17091−3624 showed pseudo-periodic flare-like events in the light curve, closely resembling those observed from GRS 1915+105. We find evidence that these phenomena are due to the same physical instability process ascribed to GRS 1915+105. Finally, we speculate that the faintness of IGR J17091−3624 could be not only due to the high distance of the source but also due to the high inclination angle of the system.