Spectral energy distributions of submm/radio bright gamma-ray burst host galaxies

TL;DR

This study models the spectral energy distributions of four gamma-ray burst host galaxies, revealing they are young starburst galaxies with high star formation rates and specific ages, based on optical to radio data.

Contribution

It provides detailed spectral energy distribution models for gamma-ray burst host galaxies, linking their optical and radio properties to starburst activity.

Findings

Host galaxies are young starbursts with ages 0.09-2.0 Gyrs.

Star formation rates are between 138 and 380 solar masses per year.

Models fit both optical and radio spectral data successfully.

Abstract

We present optical to radio spectral energy distribution fitting of the host galaxies of four long gamma-ray bursts: 980703, 000210, 000418 and 010222, which were detected at submillimetre and/or radio wavelengths. We find that only very young starburst galaxy models are consistent with the data having both blue optical colors and a pronounced submm emission. For each host we are able to construct a model consistent with the short- and long-wavelength parts of the spectra. We find galaxy ages ranging from 0.09 to 2.0 Gyrs and star formation rates ranging from 138 to 380 MSun/yr.