Hynes, R. I.; Charles, P. A.; Garcia, M. R.; Robinson, E. L.; Casares, J.; Haswell, C. A.; Kong, A. K. H.; Rupen, M.; Fender, R. P.; Wagner, R. M.; Gallo, E.; Eves, B. A. C.; Shahbaz, T. and Zurita, C.
|DOI (Digital Object Identifier) Link:||http://dx.doi.org/10.1086/424005|
|Google Scholar:||Look up in Google Scholar|
We report simultaneous X-ray and optical observations of V404 Cyg in quiescence. The X-ray flux varied dramatically by a factor of 20 during a 60 ks observation. X-ray variations were well correlated with those in Hα, although the latter include an approximately constant component as well. Correlations can also be seen with the optical continuum, although these are less clear. We see no large lag between X-ray and optical line variations; this implies they are causally connected on short timescales. As in previous observations, Hα flares exhibit a double-peaked profile suggesting emission distributed across the accretion disk. The peak separation is consistent with material extending outward to at least the circularization radius. The prompt response in the entire Hα line confirms that the variability is powered by X-ray (and/or EUV) irradiation.
|Item Type:||Journal Article|
|Keywords:||accretion, accretion disks—binaries: close—stars: individual (V404 Cygni)— X-rays: binaries|
|Academic Unit/Department:||Science > Physical Sciences
|Interdisciplinary Research Centre:||Centre for Earth, Planetary, Space and Astronomical Research (CEPSAR)|
|Depositing User:||Astrid Peterkin|
|Date Deposited:||02 Jul 2008|
|Last Modified:||14 Jan 2016 16:59|
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