1302.2663 (Daniel P. Stark et al.)

The CASSOWARY spectroscopy survey: A new sample of gravitationally lensed galaxies in SDSS    [PDF]

Daniel P. Stark, Matthew Auger, Vasily Belokurov, Tucker Jones, Brant E. Robertson, Richard S. Ellis, David J. Sand, Alexei Moiseev, Will Eagle, Thomas Myers

Bright gravitationally lensed galaxies provide our most detailed view of galaxies at high redshift. Yet as a result of the small number of ultra-bright z~2 lensed systems with confirmed redshifts, most detailed spectroscopic studies have been limited in their scope. With the goal of increasing the number of bright lensed galaxies available for detailed follow-up, we have undertaken a spectroscopic campaign targeting wide separation (>3 arcsec) galaxy-galaxy lens candidates within the Sloan Digital Sky Survey (SDSS). Building on the earlier efforts of our CASSOWARY survey, we target a large sample of candidate galaxy-galaxy lens systems in SDSS using a well-established search algorithm which identifies blue arc-like structures situated around luminous red galaxies. In this paper, we present a new redshift catalog containing 25 lensed sources in SDSS confirmed through spectroscopic follow-up of candidate galaxy-galaxy lens systems. Included in this new sample are two of the brightest galaxies (r=19.6 and 19.7) galaxies known at z~2, a low metallicity (12 + log (O/H)~8.0) extreme nebular line emitting galaxy at z=1.43, and numerous systems for which detailed follow-up will be possible. The source redshifts span 0.91 galaxies now confirmed within SDSS, it will soon be possible for the first time to develop generalized conclusions from detailed spectroscopic studies of the brightest lensed systems at high redshift.

View original: http://arxiv.org/abs/1302.2663