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.
Originalsprog | Engelsk |
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Tidsskrift | Royal Astronomical Society. Monthly Notices |
Vol/bind | 442 |
Udgave nummer | 3 |
Sider (fra-til) | 2586-2599 |
Antal sider | 14 |
ISSN | 0035-8711 |
DOI | |
Status | Udgivet - 11 aug. 2014 |