The Multiband Photometry of GRB Host Galaxies: Comparison with the Spectral Energy Distributions of Nearby and Theoretical Modeling Galaxies

Abstract

We present one of the results of $BVRI$ photometry of the hosts of GRB for the host galaxy of GRB 970508 and the theoretical modeling of its continuum spectral energy distribution (SED) to show that it is important to take into account internal extinction in the host galaxies. We compared the BVRI broad-band flux spectrum of the host to template SEDs of local starburst galaxies and found that there is a significant internal extintion in this host. Moreover, this comparison allows us to derive the absolute magnitude (M_{B_{rest}}) and rouhgly estimate reddening (A_V). Population synthesis modeling of the continuum SED for different reddening laws demostrates that the observational data of the host galaxy of GRB 970508 are best fitted by the spectral properties of a model SED with extinction of A_V\approx 2.