NOAO >   Observing Info >   Approved Programs >   2011A-0054

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Proposal Information for 2011A-0054


PI: Max Pettini, University of Cambridge, pettini@ast.cam.ac.uk
Address: Institute of Astronomy, Madingley Road, Cambridge CB3 0HA, UK

CoI: Ryan Cooke, Institute of Astronomy

Title: Probing Population III nucleosynthesis with carbon-enhanced DLAs

Abstract: High redshift damped Lyman alpha systems with metallicities less than 1/100 of solar are near-ideal environments for probing the nucleosynthesis by some of the first structures to form in the Universe. As part of this work, we recently discovered a DLA that: has an Fe abundance 1/1000 of solar, exhibits a clear `odd-even' effect, and has a C/Fe ratio 35 times greater than solar. All these characteristics are consistent with nucleosynthesis by metal-free (Population III) stars, and have so far only been seen in `Carbon-Enhanced Metal-Poor' (CEMP) stars, a class of halo stars which includes the three most Fe-poor stars known to date. Motivated by this important discovery, we now propose to use HIRES to measure the chemical composition of three other DLAs which we have identified as the most promising candidates of further examples of CEMP DLAs. With a moderate sample of such systems, it will be possible to place tighter constraints on the initial mass function of the first stars, as well as clarify the origin of the metals in CEMP stars.


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NOAO >   Observing Info >   Approved Programs >   2011A-0054

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