Spatially-resolved dust properties of the GRB 980425 host galaxy
Abstract
Gamma-ray bursts (GRBs) have been proposed as a tool for studying star formation in the Universe, so it is crucial to investigate whether their host galaxies and immediate environments are in any way special compared with other star-forming galaxies. Here we present spatially resolved maps of dust emission of the host galaxy of the closest known GRB 980425 at z=0.0085 using our new high-resolution observations from Herschel, Atacama Pathfinder Experiment (APEX), Atacama Large Millimeter Array (ALMA) and Australia Telescope Compact Array (ATCA). We modelled the spectral energy distributions of the host and of the star-forming region displaying the Wolf-Rayet signatures in the spectrum (WR region), located 800 pc from the GRB position. The host is characterised by low dust content and a high fraction of UV-visible star formation, similar to other dwarf galaxies. These galaxies are abundant in the local universe, so it is not surprising to find a GRB in one of them, assuming the correspondence between the GRB rate and star formation. The WR region contributes substantially to the host emission at the far-infrared, millimetre, and radio wavelengths and we propose that this is a consequence of its high gas density. If dense environments are also found close to the positions of other GRBs, then the ISM density should also be considered, along with metallicity, an important factor influencing whether a given stellar population can produce a GRB.
Keywords
Cite
@article{arxiv.1311.6466,
title = {Spatially-resolved dust properties of the GRB 980425 host galaxy},
author = {Michał J. Michałowski and L. K. Hunt and E. Palazzi and S. Savaglio and G. Gentile and J. Rasmussen and M. Baes and S. Basa and S. Bianchi and S. Berta and D. Burlon and J. M. Castro Ceron and S. Covino and J. -G. Cuby and V. D'Elia and P. Ferrero and D. Gotz and J. Hjorth and M. P. Koprowski and D. Le Borgne and E. Le Floc'h and D. Malesani and T. Murphy and E. Pian and S. Piranomonte and A. Rossi and J. Sollerman and N. R. Tanvir and A. de Ugarte Postigo and D. Watson and P. van der Werf and S. D. Vergani and D. Xu},
journal= {arXiv preprint arXiv:1311.6466},
year = {2014}
}
Comments
Accepted by A&A. 14 pages, 7 figures, 2 tables. V2: minor updates to match the published version