| Description |
Gamma-Ray Bursts (GRBs) are so luminous that they can shine through highly obscured galaxies, nearby and in the remote universe. GRBs enable identification of galaxies independently of their luminosity, thus singling out a population that is a potentially powerful probe of galaxy evolution. Only a minority of the host galaxies of GRBs (GRBHs) have been so far detected at sub-millimeter (submm) or mid-infrared (mid-IR) wavelengths; however, in this minority the inferred star-formation rates (SFRs) can be as high as virgul500 Msun-year, implying that they are similar to submm galaxies. On the other hand, the frequent non-detections argue against a population dominated by massive and strongly starbursting galaxies. One way to resolve this dilemma would be warm dust. At redshifts 2-4, warm dust (40-50K) would be difficult to detect in the submm bands because its peak would be too blue, and also in the mid-IR, because its peak emission would be far too red. We propose to break this possible dust-temperature redshift conspiracy with Herschel PACS+SPIRE photometry of 14 GRBHs with redshifts reaching 4.4. The sample was selected on the basis of prior Spitzer IRAC (or MIPS) detections. We already have in hand a large amount of ancillary multiwavelength data with which we can determine stellar ages and masses. We will construct spectral energy distributions from the UV to the far-IR and use them to derive bolometric luminosities and SFRs, and constrain dust mass, dust temperature, and grain properties. We will compare the dust properties with the stellar component of the galaxies, and analyze the GRBHs in the context of other high-z galaxy populations. Such a program is now possible thanks to the unique ability of Herschel to study dust emission in galaxies over a wide range of redshifts. Ultimately our proposed study of GRBHs will open a new window on the study of galaxy formation and evolution. |
| Publication |
New light on gamma-ray burst host galaxies with Herschel . Hunt L. K. et al. . Astronomy & Astrophysics, Volume 565, id.A112, 19 pp. . 565 . 10.1051/0004-6361/201323340 . 2014A&A...565A.112H ,
Two γ-ray bursts from dusty regions with little molecular gas . Hatsukade B. et al. . Nature, Volume 510, Issue 7504, pp. 247-249 (2014). . 510 . 10.1038/nature13325 . 2014Natur.510..247H ,
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