Ryan Cooke, Max Pettini, Michael Murphy
We report the identification of a very metal-poor damped Lyman-alpha system
(DLA) at z_abs = 3.067295 that is modestly carbon-enhanced, with an iron
abundance of ~1/700 solar ([Fe/H] = -2.84) and [C,O/Fe] ~ +0.6. Such an
abundance pattern is likely to be the result of nucleosynthesis by massive
stars. On the basis of 17 metal absorption lines, we derive a 2 sigma upper
limit on the DLA's kinetic temperature of T_DLA <= 4700 K. While the
best-fitting abundance pattern shows the expected hallmarks of Population III
nucleosynthesis, models of high-mass Population II stars can match the
abundance pattern almost as well. We discuss current limitations in
distinguishing between these two scenarios and the marked improvement in
identifying the remnants of Population III stars expected from the forthcoming
generation of 30-metre class telescopes.
View original:
http://arxiv.org/abs/1201.1004
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