A new candidate for probing Population III nucleosynthesis with carbon-enhanced damped Lya systems

作者：Cooke Ryan^*; Pettini Max; Murphy Michael T

来源：Monthly Notices of the Royal Astronomical Society, 2012, 425(1): 347-354.

DOI：10.1111/j.1365-2966.2012.21470.x

• galaxies: abundances
• galaxies: evolution
• quasars: absorption lines

We report the identification of a very metal poor damped Lya system (DLA) at zabs = 3.067?295 that is modestly carbon enhanced, with an iron abundance of similar to 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 2s upper limit on the DLA%26apos;s kinetic temperature of TDLA = 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-m class telescopes.

• 出版日期2012-9