V404 Cygni with Fermi-LAT [HEAP]

http://arxiv.org/abs/2107.09395


We revisit the well-studied outburst of the low mass X-ray binary (LMXB) system V404 Cygni, and claims of gamma-ray excesses observed with the Fermi-LAT instrument. Upon analysing an 11.5 year dataset with the 8-year LAT point source catalogue and 8-year background models, we find no evidence to suggest that there is high energy gamma-ray emission during the outburst period (or at any other time) from V404 Cygni. This is due to the proximity of V404 Cygni to the gamma-ray emitting blazar B2023+336, a luminous source approximately 0.3 degrees away, which causes source confusion at the position of V404 Cygni, the luminous gamma-ray background, and the use of older background models and catalogues in previous studies.

Read this paper on arXiv…

M. Harvey, C. Rulten and P. Chadwick
Wed, 21 Jul 21
65/83

Comments: 11 pages, 6 figures. Accepted for publication in Monthly Notices of the Royal Astronomical Society