V404 Cygni with Fermi-LAT. Issue 4 (22nd July 2021)

• Record Type: Journal Article
• Authors: Harvey, Max; Rulten, Cameron B; Chadwick, Paula M
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 506:Issue 4(2021)
• Page Start: 6029
• Page End: 6038
• Publication Date: 2021-07-22
• Subjects: black hole physics -- gamma-rays: stars -- X-rays: binaries; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stab2097
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: We revisit the well-studied outburst of the low-mass X-ray binary (LMXB) system V404 Cygni, and claims of γ-ray excesses observed with the Fermi -LAT instrument. Upon analysing an 11.5 yr data set with the 8-yr LAT point source catalogue and 8-yr background models, we find no evidence to suggest that there is high energy γ-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 γ-ray emitting blazar B2023+336, a luminous source approximately 0.3 ○ away, which causes source confusion at the position of V404 Cygni, the luminous γ-ray background, and the use of older background models and catalogues in previous studies.