A Galaxy at Record Redshift?

Skimming through the arXiv this morning I discovered a paper by Zitrin et al. with the following abstract:



I’m not sure if the figures are all significant, but a redshift of z=8.68 makes this the most distant spectroscopically confirmed galaxy on record with a present proper distance of about 9.3 Gpc according to the standard cosmological model, just pipping the previous record holder (whose redshift was in any case disputed). Light from this galaxy has taken about 13.1 Gyr to reach us; that means light set out from it when the Universe was only about 4% of its current age, only about 600 million years after the Big Bang. (Those figures were obtained using the inestimable Ned Wright’s cosmology calculator.)

We are presumably seeing a very young object, in which stars are forming at a considerable rate to account for its brightness. We don’t know exactly when the first stars formed and began to ionize the intergalactic medium, but every time the cosmic distance record is broken we push that time back closer to the Big Bang.

Mind you, I can’t say I’m overwhelmingly convinced by the identification of the redshifted Lyman-α line:

high_zBut what do I know? I’m a theorist whose suspicious of data. Any observers care to comment?

2 Responses to “A Galaxy at Record Redshift?”

  1. Well the rest of the world picks it up now too.

  2. […] as I have been on previous occasions (e.g. here), I remain unconvinced. Any experts out there want to tell me I’m […]

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