Spectro-photometric study of the GRB 030329 host galaxy

Abstract

In this study optical/near-infrared(NIR) broad band photometry and optical spectroscopic observations of the GRB 030329 host galaxy are presented. The Spectral Energy Distribution (SED) of the host is consistent with a starburst galaxy template with a dominant stellar population age of ~150 Myr and an extinction Av ~0.6. Analysis of the spectral emission lines shows that the host is likely a low metallicity galaxy. Two independent diagnostics, based on the restframe UV continuum and the [OII] line flux, provide a consistent unextincted star formation rate of SFR ~0.6 Mo yr^-1. The low absolute magnitude of the host (M_B ~ -16.5) implies a high specific star formation rate value, SSFR = ~34 Mo yr^-1 (L/L*)^-1.

4 pages, 2 figures, accepted for publication in Il nuovo cimento (4th Workshop Gamma-Ray Bursts in the Afterglow Era, Rome, 18-22 October 2004)