Abstract
We report near-simultaneous multicolor (RIYJHK) observations made with the MAGNUM 2 m telescope of the gamma-ray burst GRB 050904 detected by the Swift satellite. The spectral energy distribution shows a very large break between the I and J bands. Using intergalactic transmissions measured from high-redshift quasars, we show that the observations place a 95% confidence lower limit of z = 6.18 on the object, consistent with a later measured spectroscopic redshift of 6.29 obtained by Kawai et al. with the Subaru telescope. We show that the break strength in the R and I bands is consistent with that measured in the quasars. Finally, we consider the implications for the star formation history at high redshift.
Original language | English |
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Pages (from-to) | 851-855 |
Number of pages | 5 |
Journal | Astrophysical Journal |
Volume | 645 |
Issue number | 2 I |
DOIs | |
Publication status | Published - 10 Jul 2006 |