Cosmological Implications of the Very High Redshift GRB 050904
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.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- July 2006
- DOI:
- 10.1086/504414
- arXiv:
- arXiv:astro-ph/0509697
- Bibcode:
- 2006ApJ...645..851P
- Keywords:
-
- Cosmology: Observations;
- Galaxies: Distances and Redshifts;
- Gamma Rays: Bursts;
- Astrophysics
- E-Print:
- Accepted for publication in the Astrophysical Journal. Expanded introduction and discussion