1999/11/11 by Ann A. Esin, Erik Kuulkers, E. Kuulkers +2 · 50 citations
Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics #Black hole (networking) #Computer science #Flux (metallurgy) #Gamma-ray bursts and supernovae #Image warping #Irradiation #Light curve #Materials science #Nuclear physics #Physics #astro-ph
paper · pdf · doi:10.1086/308615
published in The Astrophysical Journal 532(2), 1069-1077 (IOP Publishing) · 12 pages, including 4 figures and a table, LaTeX (emulateapj.sty; newapa.sty for bibliography definitions); accepted for publication in ApJ
arxiv created 1999/11/11 · openalex publication_date 2000/04/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We test whether the model proposed by Esin et al. to explain X-ray observations of the black hole soft X-ray transient GRS 1124-68 in outburst can also explain the optical light curves of a similar object, A0620-00. We show that to reproduce the observed X-ray to optical flux ratio in A0620-00, we need to assume X-ray irradiation of the outer disk that is significantly in excess of what is expected for a standard planar disk. With enhanced irradiation, the Esin et al. model can reproduce the optical evolution of A0620-00 in outburst very well. Though we find that optical observations of GRS 1124-68 also imply enhanced X-ray heating of the outer disk, the irradiation appears to be a factor of ~3 weaker in this system than in A0620-00. This is surprising, since GRS 1124-68 has a larger disk. We speculate that enhanced irradiation may be due to disk warping, and that the degree of warping differs between the two binaries.