Bibcode
Koljonen, Karri; Russell, David; Corral-Santana, Jesus; Armas Padilla, M.; Munoz-Darias, T.; Lewis, Fraser
Bibliographical reference
American Astronomical Society, AAS Meeting #228, id.#402.06
Advertised on:
6
2016
Citations
0
Refereed citations
0
Description
In the shadows of the V404 Cyg outburst in the summer of 2015, GS
1354-64 (BW Cir) went into outburst as well. We followed the evolution
of the outburst at optical, UV and X-ray wavelengths using Faulkes
Telescope South, SMARTS and Swift. The outburst was found to stay in the
hard X-ray state, albeit being anomalously luminous with a peak X-ray
luminosity exceeding 0.15 LEdd, which could be the most
luminous hard state observed in a black hole X-ray binary. In this talk
I will present our results showing that the the outburst evolution at
all wavelengths can be explained by the disk instability model with
irradiation and disk evaporation/condensation. In addition, I will
present our long-term optical monitoring results that show a
statistically significant, slow rise of the source brightness over the 7
years prior to the 2015 outburst. This could be the much-sought
observational evidence of matter slowly accumulating in the accretion
disk, and subsequently getting optically brighter, as predicted by the
disk instability model.