FRB 20240114A: A potential association with a galaxy cluster at 425 Mpc
ATel #16426; Brendan O'Connor, Mohit Bhardwaj, Antonella Palmese (Carnegie Mellon University)
on 30 Jan 2024; 23:08 UT
Credential Certification: Brendan O'Connor (oconnorb@gwmail.gwu.edu)
Subjects: Radio, Optical, Fast Radio Burst
We report on the alignment of the recently reported repeating FRB 20240114A (ATel #16420) with a galaxy cluster at ~425 Mpc. The CHIME FRB localization intersects multiple galaxy clusters [1,2] identified in DESI legacy imaging at redshifts z~0.09, 0.189, and 0.4. The lowest redshift cluster is centered at RA, DEC (J2000) = 321.9511 deg, +4.5185 deg with a physical size of R_200 = 1.2 Mpc, corresponding to angular size of ~12 arcmin. The brightest cluster galaxy (BCG) has a spectroscopic redshift of 0.0906 [1], and the total mass of the cluster is log(M_500/M_sun) ~ 14.3 [1]. The brightest galaxy within the CHIME FRB localization (ATel #16420) lies at RA, DEC (J2000) = 321.9203 deg, +4.3532 deg, corresponding to an offset of ~10 arcmin from the cluster center. This galaxy has a photometric redshift of z_phot = 0.098 +/- 0.019 [3] from the legacy survey DR9. This photometric redshift is consistent with the redshift of the BCG, and we suggest that it may be a cluster member. There are also two other likely cluster members within 2 arcmin of the CHIME localization at RA, DEC (J2000) = 321.8841 deg, +4.3422 deg, and RA, DEC (J2000) = 321.8954 deg, +4.3736 deg.
If associated with the FRB, this may provide an important probe of the both the intracluster medium and intergalactic medium contribution to the DM, which suggests a further distance than 425 Mpc. Even if associated with a more distant galaxy (or a member of the other clusters), the contribution of the low redshift cluster's halo to the DM must be taken into account.
Further radio observations to obtain a precise localization of the repeater are encouraged.
[1] Zou H., et al., 2021, ApJS, 253, 56
[2] Zou H, et al., 2019, ApJS, 242, 8
[3] Zhou R., et al., 2023, JCAP, 2023, 097