NOAO >   Observing Info >   Approved Programs >   2009B-0016

Small NOAO Logo

Proposal Information for 2009B-0016


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

CoI: Ryan Cooke, Institute of Astronomy

Title: The Most Metal-Poor DLAs as Probes of Early Nucleosynthesis

Abstract: High redshift damped Lyman alpha systems (DLAs) 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. Unlike metal-poor stars in the Galactic halo, the chemical composition of DLAs can be measured rather straightforwardly, free from concerns about the geometry of the absorber, radiation transfer effects, and unseen ion stages. The most successful computer simulations of galaxy formation show that very metal-poor DLAs arise in low mass halos, which have undergone little \textitin situ star formation and are essentially dust-free. While they are rare, we have recently learnt how to select such DLAs from low resolution SDSS spectra. With this application we propose to follow-up some of our best candidates with high resolution echelle spectroscopy which will allow us, in particular, to measure the relative abundances of the C, N, O group of elements in this all-important metallicity regime. This proposal was awarded one HIRES night in March 2009, but no data were obtained because the telescope remained closed all night due to high winds and ice. This is a resubmission of the same proposal, with targets accessible in semester 2009B.


National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360



NOAO >   Observing Info >   Approved Programs >   2009B-0016

noaoprop-help@noao.edu

Small NOAO Logo