The host of GRB/XRF 030528 – an actively star forming galaxy at z = 0.782
Max-Planck-Institut für extraterrestrische Physik, Giessenbachstrasse, 85748 Garching, Germany e-mail: firstname.lastname@example.org
Accepted: 11 August 2005
An important parameter for the distinction of X-ray flashes, X-ray rich bursts and Gamma-ray bursts in the rest frame is the distance to the explosion site. Here we report on the spectroscopic redshift determination of the host galaxy of XRF/GRB 030528 using the ESO VLT FORS2 instrument. From the strong oxygen and hydrogen emission lines the redshift was measured to be . Obtaining the line luminosities and ratios we find that the host is consistent with being an actively star forming galaxy with sub-solar metallicity. With a stellar mass of ~1010 the host is placed among the most massive GRB host galaxies at a similar redshift. Estimating the redshifted properties of the prompt emission, we find that XRF/GRB 030528 would be classified as an X-ray rich burst in the rest frame rather than an X-ray flash in the typically-used observer frame.
Key words: gamma rays: bursts
© ESO, 2005