A blazar as the likely counterpart to 4FGL J0647.7-4418 instead of a gamma-ray binary

Abstract

The persistent gamma-ray source 4FGL J0647.7-4418 is tentatively associated in the latest Fermi catalogue with the sub-dwarf O-type X-ray binary HD 49798. However, an AGN candidate is also mentioned as an alternative identification in updated versions of the catalogue accompanying paper. If the first association were correct, this would add HD 49798 to the handful of currently known gamma-ray binaries and, therefore, represent a significant breakthrough not only because of a new member addition, but also because of the apparent white dwarf companion in this system. Despite these perspectives, here we show that the stellar association is likely wrong and that the proposed AGN object, well inside the Fermi 95% confidence ellipse, is a more conceivable counterpart candidate to the Fermi source due to its strong blazar similarities.

arXiv comment7 pages, 9 Figures, accepted for publication in MNRAS

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Cited by in corpus (4)

• Incremental Fermi Large Area Telescope Fourth Source Catalog
• The Fourth Catalog of Active Galactic Nuclei Detected by the Fermi Large Area Telescope -- Data Release 3
• A blazar candidate for the Fermi source 4FGL J1848.7-0129
• Timing the X-ray pulsating companion of the hot-subdwarf HD 49798 with NICER