PI: Sara Ellison, University of Victoria, email@example.com
Address: Department of Physics and Astronomy, PO Box 3055, Victoria, BC, V8W 3P6, Canada
CoI: Joe Hennawi, MPIA Heidelberg
CoI: Sebastian Lopez, Universidad de Chile
CoI: J. Xavier Prochaska, UC Santa Cruz
Title: Accurate redshifts for distant quasars: probing massive galaxies through QSO absorption lines
Abstract: Surveys for damped Lyman alpha (DLA) systems in QSO spectra universally exclude 'proximate' systems (PDLAs) with small velocity offsets from the QSO, due to concerns about their origin and the impact of the quasar's ionizing radiation. We have recently conducted the first systematic survey of 15 PDLAs within 3000 km/s of the background QSO and found that they do indeed differ significantly from the intervening population, empirically vindicating their exclusion from general DLA surveys. These differences are present at all velocities, which is surprising as the velocity range probes scales up to 10 Mpc. However, the current uncertainty of QSO redshifts from optical spectra can be as large as 1000 km/s. We propose IR spectroscopy for a sample of QSOs with PDLAs to determine redshifts accurate to 40 km/s to assess the velocity dependence of DLA proximity, measure massive galaxy kinematics at high-z and pre-screen PDLAs for future echelle observations.
National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360