Abstract
The prompt γ-ray emission from γ-ray bursts (GRBs) should be detectable out to distances of z > 10 (ref. 1), and should therefore provide an excellent probe of the evolution of cosmic star formation, reionization of the intergalactic medium, and the metal enrichment history of the Universe 1-4. Hitherto, the highest measured redshift for a GRB has been z = 4.50 (ref. 5). Here we report the optical spectrum of the afterglow of GRB 050904 obtained 3.4 days after the burst; the spectrum shows a clear continuum at the long-wavelength end of the spectrum with a sharp cut-off at around 9,000 Å due to Lyman α absorption at z ≈ 6.3 (with a damping wing). A system of absorption lines of heavy elements at z = 6.295 ± 0.002 was also detected, yielding the precise measurement of the redshift. The Si II fine-structure lines suggest a dense, metal-enriched environment around the progenitor of the GRB.
Original language | English |
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Pages (from-to) | 184-186 |
Number of pages | 3 |
Journal | Nature |
Volume | 440 |
Issue number | 7081 |
DOIs | |
Publication status | Published - 2006 Mar 9 |
ASJC Scopus subject areas
- General