GRB 051008: a long, spectrally hard dust-obscured GRB in a Lyman-break galaxy at z = 2.8

A. A. Volnova, A. S. Pozanenko, J. Gorosabel, D. A. Perley, D. D. Frederiks, D. A. Kann, V. V. Rumyantsev, V. V. Biryukov, V. V. Biryukov, A. J. Castro-Tirado, P. Ferrero, S. V. Golenetskii, S. Klose, V. M. Loznikov, P. Yu. Minaev, B. Stecklum, D. S. Svinkin, A. E. Tsvetkova, Antonio de Ugarte Postigo, M. V. Ulanov

9 Citationer (Scopus)

Abstract

We present observations of the dark gamma-ray burst GRB 051008 provided by Swift/BAT, Swift/XRT, Konus-WIND, INTEGRAL/SPI-ACS in the high-energy domain and the Shajn, Swift/UVOT, Tautenburg, NOT, Gemini and Keck I telescopes in the optical and near-infrared bands. The burst was detected only in gamma- and X-rays and neither a prompt optical nor a radio afterglow was detected down to deep limits. We identified the host galaxy of the burst, which is a typical Lyman-break galaxy (LBG) with R-magnitude of 24.06 ± 0.10 mag. A redshift of the galaxy of z=2.77+0.15−0.20 is measured photometrically due to the presence of a clear, strong Lyman-break feature. The host galaxy is a small starburst galaxy with moderate intrinsic extinction (AV = 0.3) and has a star formation rate of ∼60 M yr−1 typical for LBGs. It is one of the few cases where a GRB host has been found to be a classical LBG. Using the redshift we estimate the isotropic-equivalent radiated energy of the burst to be Eiso = (1.15 ± 0.20) × 1054 erg. We also provide evidence in favour of the hypothesis that the darkness of GRB 051008 is due to local absorption resulting from a dense circumburst medium.
OriginalsprogEngelsk
TidsskriftRoyal Astronomical Society. Monthly Notices
Vol/bind442
Udgave nummer3
Sider (fra-til)2586-2599
Antal sider14
ISSN0035-8711
DOI
StatusUdgivet - 11 aug. 2014

Citationsformater