Spectral Energy Distributions of Gamma Ray Burst Host Galaxies

This work is concentrated on the fitting of the
Spectral Energy Distribution (SED) templates to the
broad-band observational data of Gamma Ray Bursts
(GRB) host galaxies, which were bright in
submillimetre and/or radio wavelengths, namely hosts
of GRB 980703, GRB 000210, GRB 000418 and GRB 010222.
This is the first successful entire SED fitting, from
optical to radio wavelengths, achieved for GRB hosts.
I present constraints on their properties, including
the need for high dust temperatures, high star
formation rates (SFR) and low ages. I estimated very
conservative and robust lower limits on the dust
temperatures in a range from T 29 K to T 59 K.
Their SFRs derived from infrared emission range from
179 to 1211 solar masses per year and it places GRB
hosts in a category of highly star-forming galaxies.
I propose that the seeming contradiction of high SFRs
and blue optical colors of GRB hosts can be explained
by their low ages in a range from 90 Myr to 2 Gyr.

Autorentext

Michal Jerzy Michalowski, MSc: studied Astronomy at the DarkCosmology Centre, Niels Bohr Institute, University of Copenhagen,Denmark and Astronomical Observatory, Adam Mickiewicz University,Poznan, Poland. Currently a PhD student at the Dark CosmologyCentre. Main research interests: star-forming galaxies, gamma-rayburst hosts, submm galaxies.

Klappentext

This work is concentrated on the fitting of theSpectral Energy Distribution (SED) templates to thebroad-band observational data of Gamma Ray Bursts(GRB) host galaxies, which were bright insubmillimetre and/or radio wavelengths, namely hostsof GRB 980703, GRB 000210, GRB 000418 and GRB 010222.This is the first successful entire SED fitting, fromoptical to radio wavelengths, achieved for GRB hosts.I present constraints on their properties, includingthe need for high dust temperatures, high starformation rates (SFR) and low ages. I estimated veryconservative and robust lower limits on the dusttemperatures in a range from T 29 K to T 59 K.Their SFRs derived from infrared emission range from179 to 1211 solar masses per year and it places GRBhosts in a category of highly star-forming galaxies.I propose that the seeming contradiction of high SFRsand blue optical colors of GRB hosts can be explainedby their low ages in a range from 90 Myr to 2 Gyr.