PI: Gendith Sardane, University of Pittsburgh, firstname.lastname@example.org
Address: Department of Physics and Astronomy, 100 Allen Hall, Pittsburgh, PA, 15260, USA
CoI: David Turnshek, University of Pittsburgh
CoI: Sandhya Rao, University of Pittsburgh
Title: Mapping cool, metal-rich gas around z<0.08 galaxies
Abstract: We propose GMOS-N queue observations to obtain redshifts of candidate galaxies in order to identify galaxies associated with a sample of rare gaseous regions with redshifts z<0.08. We will identify all galaxies down to SDSS r-band luminosity of 0.01L* in the vicinity of CaII absorbing regions seen in background quasar spectra. The presence of CaII absorption is indicative of cool neutral gas that may contain molecules and dust. Consequently, the study of the association between cool, metal-rich gas and galaxies down to very low luminosity will lead to important constraints on the overall existence and extent of cool gas in the regions around galaxies, which in turn constrains models of inflows, outflows, star formation, feedback, and chemical enrichment. This program is unique among those aimed at investigating the association between intervening quasar absorbers and galaxies. Unlike more common UV resonance lines, the CaII doublet is found at optical wavelengths. Therefore, although CaII absorption is rare, it is possible to search for it in huge numbers of optical SDSS quasar spectra and then use the results to perform follow-up studies at very low redshift, in this case at z<0.08. Our program will find galaxies, including very faint dwarfs, within 100 kpc of the quasar sightlines, enabling us to constrain just how far these gaseous regions are from galaxies. A common criticism of this type of work is that a galaxy could be hidden under a quasar's PSF; however, due to the low absorber redshift values, interference from the glare of the quasar will be negligible. In total we have over 260 galaxy candidates along 15 sightlines to observe, and we request time to observe the first 5 fields in Semester B.
National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360