A Redshift Survey of Galaxies and Quasars in the Background of the Andromeda and Triangulum Galaxies

The SPLASH (Spectroscopic and Photometric Landscape of Andromeda’s Stellar halo) and the T-REX (Triangulum Extended) surveys, carried out using the Keck II 10-meter telescope and the DEIMOS spectrograph, were designed to study stars in the halo of the Andromeda galaxy (M31) and the Triangulum galaxy (M33) respectively. An unintended by-product of the SPLASH and TREX surveys is a spectroscopic redshift survey of a few thousand distant galaxies and a couple hundred quasars in the background of M31 and M33. What is special about these background objects is that, unlike other distant galaxy redshift survey targets, these objects are star-like in their image morphology. In this poster, we present the physical properties of these background galaxies and quasars – e.g., redshift distribution, color-magnitude distribution, emission line strengths ratios. We plan to compare these above-mentioned properties for the SPLASH and TREX background objects to those of galaxies and quasars targeted in ore traditional redshift surveys such as the DEEP2/DEEP3 redshift surveys.

This research was supported by NASA/STSci and the National Science Foundation. Most of this work was carried out by high school students working under the auspices of the Science Internship Program (SIP) at UC Santa Cruz.