High-resolution Giant Metrewave Radio Telescope H i 21 cm Imaging of the Host Galaxy of FRB 20250316A

Abstract We report Giant Metrewave Radio Telescope (GMRT) H i 21 cm imaging of NGC 4141, the host galaxy of FRB 20250316A at z = 0.0063. Our GMRT H i 21 cm images have spatial resolutions, at z ≈ 0.0063, of ≈0.48–8.0 kpc, and provide evidence for (i) a companion galaxy, LEDA 2582852, to the southwest, (ii) a nearby (27 kpc distant) H i cloud to the southwest, (iii) disturbances in the H i distributions of both NGC 4141 and LEDA 2582852, and (iv) high H i column densities in the southwestern outskirts of NGC 4141. A Sloan Digital Sky Survey spectrum yields a low metallicity and a high star formation rate (SFR) surface density in the southwestern disk of NGC 4141, and an H α -based SFR estimate that is significantly higher than that at the same location from the Galaxy Evolution Explorer near-ultraviolet image, indicating a recent burst of star formation. The total SFR of NGC 4141 is also found to be higher via the H α line than from the 1.4 GHz radio continuum. The above evidence indicates that NGC 4141 has recently (within the last ≈3 Myr) acquired metal-poor gas, via either a merger or accretion, that resulted in the southwestern starburst and that may also have triggered large-scale star-formation activity in NGC 4141, resulting in the formation of the stellar progenitor of FRB 20250316A and the other transients. Our highest-resolution (480 pc) GMRT H i 21 cm image finds no H i 21 cm emission from the location of FRB 20250316A or the nearby star-forming region, suggesting that most of the H i here has been either ionized or converted into the molecular phase. Our nondetection of continuum emission at the location of FRB 20250316A yields the 3 σ upper limit νL 1.38 GHz < 4.4 × 10 34 erg s −1 on the 1.38 GHz radio luminosity of a putative persistent radio source associated with FRB 20250316A, one of the strongest constraints on the radio luminosity of such an associated persistent radio source.