Another Short-burst Host Galaxy with an Optically Obscured High Star Formation Rate: The Case of GRB 071227
Palazzi, E.; Greiner, J.; Hunt, L. K.; Klose, S.; Nicuesa Guelbenzu, A.; Kann, D. A.; Rossi, A.; Michałowski, M. J.; Gorosabel, J.; Schmidl, S.; Savaglio, S.; McKenzie, M. R. G.
Germany, United Kingdom, Italy, Spain
Abstract
We report on radio continuum observations of the host galaxy of the short gamma-ray burst 071227 (z = 0.381) with the Australia Telescope Compact Array. We detect the galaxy in the 5.5 GHz band with an integrated flux density of F ν = 43 ± 11 μJy, corresponding to an unobscured star-formation rate of about 24 M ⊙ yr-1, 40 times higher than what was found from optical emission lines. Among the ~30 well-identified and studied host galaxies of short bursts this is the third case where the host is found to undergo an episode of intense star formation. This suggests that a fraction of all short-burst progenitors hosted in star-forming galaxies could be physically related to recent star formation activity, implying a relatively short merger timescale.