The host galaxy of FRB 20171020A revisited

Abstract The putative host galaxy of FRB 20171020A was first identified as ESO 601-G036 in 2018, but no repeat bursts have been detected, direct confirmation the remains elusive. In light recent developments field, we re-examine this and determine a new association confidence level 98%. At 37 Mpc, makes third closest to be date an apparently non-repeating (with estimated repetition rate limit $<$ $0.011$ per day above $10^{39}$ erg). Due its close distance, are able perform detailed multi-wavelength analysis on system. Follow-up observations confirm typical star-forming with H i stellar masses $\log_{10}\!(M_{\rm{H\,{\small I}}} / M_\odot) \sim 9.2$ $\log_{10}\!(M_\star = 8.64^{+0.03}_{-0.15}$ , star formation $\text{SFR} 0.09 \pm 0.01\,{\rm M}_\odot\,\text{yr}^{-1}$ . We detect, for time, diffuse gaseous tail ( 8.3$ ) extending south-west that suggests interactions, likely confirmed nearby companion 601-G037. 601-G037 is shred located south has arc-like morphology, about order magnitude less massive, lower gas metallicity indicative younger population. properties system indicate ongoing minor merger event, which affecting overall component stars within Such activity consistent current progenitor models involving magnetars signs interactions other galaxies.