Swift-XRT detection at the location of the FBOT candidate AT2024qfm
ATel #16748; R. Margutti, Nayana AJ (UC Berkeley), H. Sears (Northwestern U.)
on 1 Aug 2024; 18:26 UT
Credential Certification: Raffaella Margutti (rafmargutti@gmail.com)
Subjects: X-ray, Supernovae, Transient
Referred to by ATel #: 16757
We report the detection of bright soft X-ray emission with Swift-XRT at the location of AT2024qfm (M. Fulton et al., Astro Note 2024-206). A soft X-ray source is detected with an approximate count-rate of 1e-2 c/s (0.3-10 keV), which corresponds to an approximate flux of 5e-13 erg/cm2/s. For the SDSS photometric redshift of z = 0.19 +/- 0.05, and an assumed power-law spectrum with photon index Gamma=2, the corresponding luminosity is ~5e+43 erg/s. As of a few days after peak, and if physically associated with AT2024qfm, this would make AT2024qfm more X-ray luminous than the prototypical FBOT event AT2018cow, but less luminous than other FBOTs (e.g., Migliori et al., ApJL, 963, 24). Further X-ray observations will map the temporal evolution of this source.
We thank the entire Swift team for rapidly executing these observations.
