NOAO >   Observing Info >   Approved Programs >   2003B-0321

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Proposal Information for 2003B-0321


PI: James Rhoads, STScI, rhoads@stsci.edu
Address: 3700 San Martin Drive, Baltimore, MD 21218, USA

CoI: Sangeeta Malhotra, STScI
CoI: Arjun Dey, NOAO
CoI: Buell Jannuzi, NOAO

Title: Lyman Alpha Galaxies and galaxy formation scenarios

Abstract: The Large Area Lyman Alpha survey has successfully identified the population of young \lya emitting galaxies predicted over 30 years ago. The high \lya equivalent widths seen in our z=4.5 sources suggest young ages (< 10^7 years) and low metallicities, making these very interesting objects to study in the context of galaxy formation. We have begun to do exactly this using correlation function of LALA galaxies, with puzzling initial results. Before this leads to more complications in theoretical galaxy formation scenarios, we would like to put the observational results on a firm footing. We therefore ask for one night of Keck/Deimos time for spectroscopic confirmation of 50 secure LALA sources at z=4.5, and a similar number of fainter sources, in order to (1) characterize our completeness, and (2) weed out foreground emission line galaxies which affect the small scale correlation function. The excellent match between wide-field capabilities of DEIMOS and LALA will allow the most complete confirmation and characterization of the high redshift \lya population yet in terms of photometric sample reliability, while our planned spectra of foreground objects will characterize star formation in emission line selected galaxies at 0.3 < z < 0.8. The spectroscopic sample will get us a clean measurement of the small scale correlations among \lya galaxies (clearly seen in our photometric sample). This will let us derive the halo mass, occupancy number, and duty cycle of these objects, and hence better how \lya sources fit into the bigger picture of galaxy formation.


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



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