A new candidate for probing Population III nucleosynthesis with
  carbon-enhanced damped Lyman-alpha systems
  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, which is broadly
consistent with the range of spin temperature estimates for DLAs at this
redshift and metallicity. 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.
