Poster Presentation

ALMA Observations of Dust-obscured GRB Host Galaxies

Author(s): Yu-Hsiu Huang (NTU/ASIAA) Wei-Hao Wang (ASIAA)

Presenter: Yu-Hsiu Huang (NTU/ASIAA)

The long gamma-ray burst (GRB) rate is believed to trace the cosmic star-formation history and the dust-obscured GRBs are expected to originate from dusty star-forming regions. Dust absorbs starlight and re-emits in the infrared and the sub-millimeter. Hence, to fully understand the environmental properties of the host galaxies and the connection between the hosts and the dusty bursts, infrared and sub-millimeter observations are required. In this talk, I will present ALMA band 7 observations of six z >1.5 dust-obscured GRB host galaxies. The resulting sensitivity is around 0.04 mJy beam−1and the spatial resolution is about 0.45′′×0.33′′(FWHM). We have three detections out of the six targets and we fit SED to each sample to obtain the infrared luminosity and the infrared star-formation rate. The data provide insights into the dust properties of the GRB host galaxies. Combined with multi-wavelength observations, our analysis suggests that the darkness of the GRB afterglow is confined to the narrow line of sights and cannot represent the global dust properties of the host galaxy.