Detection of a Radio Source in the Candidate Host Galaxy of FRB 20240209A
ATel #16701; C. J. Law (Caltech), M. Bhardwaj (CMU), S. Burke-Spolaor, R. Anna Thomas (WVU), P. Demorest (NRAO), G. C. Bower (ASIAA)
on 10 Jul 2024; 14:18 UT
Credential Certification: Casey Law (claw@astro.caltech.edu)
Subjects: Radio, Fast Radio Burst
We conducted four hours of radio follow-up observations FRB 20240209A with the Very Large Array (VLA) and the realfast transient search system (program code 24A-486; PI Law). The observations were done in two, 2-hour segments on July 2 and July 5, in response to recent activity reported by CHIME/FRB (ATel #16670). The realfast system observed from 1-2 GHz with a sampling time of 10 ms and a field of view that included the CHIME/FRB localization uncertainty. No bursts were detected to a limiting sensitivity of approximately 0.9 Jy ms (8 sigma).
In parallel with the fast transient search, we recorded slow visibility data suitable for sensitive radio imaging to search for a persistent radio counterpart to the FRB. Using one of the two data sets, we generate images of the FRB localization region, including the candidate host galaxy, PSO J289.8503+86.0609 (ATel #16682). We identify only one radio source in the 3sigma localization region and it is coincident with the candidate host galaxy. The radio source has an integrated flux of 265+-56, 204+-43, 112 +- 25 microJy at of 1.16, 1.48, and 1.84 GHz, respectively.
The radio source location is 19:19:24.15 +- 0.02, 86:03:39.7 +- 0.5 (at 1.84 GHz) and has a full-width at half-maximum ellipse of (7.1", 3.5", -25 deg). The position and shape are consistent with an unresolved source at or near the nucleus of proposed host galaxy. At the redshift of the candidate FRB host galaxy (ATel #16686), the flux density of the radio emission corresponds to a radio luminosity of ~1e29 erg/s/Hz. New observations will be required to associate the FRB to radio counterpart, as well as distinguish the radio counterpart from star-formation or nuclear emission in the proposed host galaxy.
We thank the NRAO director for approving of this discretionary time request.
