2005A&A...444..711G

We present broad band photometry and spectroscopic observations of the host galaxy of GRB 030329. Analysis of the spectral emission lines shows that the host is likely a low metallicity galaxy (Z∼0.004). The spectral energy distribution (SED) constructed with the photometric points has been fitted using synthetic and observational templates. The best SED fit is obtained with a starburst template with an age of ∼150Myr and an extinction A_v∼0.6. We find that the GRB 030329 host galaxy is a subluminous galaxy (L∼0.016L^*) with a stellar mass of >10⁸M_☉. Three independent diagnostics, based on the restframe UV continuum, the [OII], and the Balmer emission lines, provide a consistent unextinguished star formation rate of ∼0.6M_☉/yr, implying a high unextinguished specific star formation rate (∼34M_☉/yr/[(L/L^*)]). We estimate that the unextinguished specific star formation rate of the GRB 030329 host is higher than ∼93.5% of the galaxies at a similar redshift.