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arXiv · astro-ph/9808188

Spectroscopy of the Host Galaxy of the Gamma--Ray Burst 980703

S. G. Djorgovski·S. R. Kulkarni·J. S. Bloom·R. Goodrich·D. A. Frail·L. Piro·E. Palazzi
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Abstract

We present spectroscopic observations of the host galaxy of the gamma-ray burst (GRB) 980703. Several emission and absorption features are detected, making the redshift, z = 0.966, completely unambiguous. This is only the third known redshift for a GRB host. The implied isotropic gamma-ray energy release from the burst is in excess of 10^{53} erg, for a reasonable choice of cosmological parameters. The spectroscopic properties of the host galaxy are typical for a star formation powered object. Using the observed value of the Balmer decrement, we derived the extinction in the galaxy's restframe, A_V = 0.3 +- 0.3 mag. Using three different star formation rate indicators, we estimate SFR ~ 10 Msun/yr, or higher, depending on the extinction, with a lower limit of SFR > 7 Msun/yr. This is the highest value of the star formation rate measured for a GRB galaxy so far, and it gives some support to the idea that GRBs are closely related to massive star formation.

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S. G. Djorgovski, S. R. Kulkarni, J. S. Bloom, R. Goodrich, D. A. Frail, L. Piro, E. Palazzi. 1998-08-19. Spectroscopy of the Host Galaxy of the Gamma--Ray Burst 980703. https://doi.org/10.1086/311729

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