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Cosmological Implications of the Very High Redshift GRB 050904

P. A. Price·L. L. Cowie·T. Minezaki·B. P. Schmidt·A. Songaila·Y. Yoshii
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Abstract

We report near simultaneous multi-color (RIYJHK) observations made with the MAGNUM 2m 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. (2005) 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.

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P. A. Price, L. L. Cowie, T. Minezaki, B. P. Schmidt, A. Songaila, Y. Yoshii. 2006-03-21. Cosmological Implications of the Very High Redshift GRB 050904. https://doi.org/10.1086/504414

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