Keck Spectroscopy and Redshift of the Putative Host Galaxy of the Repeating FRB 20240209A
ATel #16686; Yuxin (Vic) Dong (Northwestern), on behalf of the CHIME/FRB Collaboration
on 3 Jul 2024; 14:47 UT
Credential Certification: Wen-fai Fong (wfong@northwestern.edu)
Subjects: Optical, Fast Radio Burst
Referred to by ATel #: 16701
The CHIME/FRB Collaboration reports on optical spectroscopy of the most probable host galaxy for the active repeating FRB 20240209A (ATel #16670, ATel #16682). We obtained 2x180-sec of observations of the putative host galaxy, PSO J289.8503+86.0609, of FRB 20240209A with the LRIS optical spectrograph mounted on the Keck I telescope at Mauna Kea, Hawaii on 29 June, 2024 UT (PI: A. Miller). Observations were taken at an airmass of 2.47 in ~1 arcsec seeing, covering approximately 3300-10200 Ang. We detect several absorption features including CaII H&K, Mg, NaD, and TiO, as well as a strong 4000 Ang break, at a common redshift of z=0.1384 +/- 0.0004. The observed spectral features, coupled with the lack of strong emission lines, are indicative of a quiescent host galaxy for the repeating FRB 20240209A.
We thank Chang Liu (Northwestern) for initial, rapid reduction and consultation on the spectrum, and the Keck Observatory staff Sherry Yeh and Tony Connors for supporting the scheduled observations.
