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arXiv · 2107.09395

V404 Cygni with Fermi-LAT

Max Harvey·Cameron B. Rulten·Paula M. Chadwick
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Abstract

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.

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Max Harvey, Cameron B. Rulten, Paula M. Chadwick. 2021-07-20. V404 Cygni with Fermi-LAT. https://doi.org/10.1093/mnras/stab2097

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