THE ATACAMA COSMOLOGY TELESCOPE: PHYSICAL PROPERTIES OF SUNYAEV-ZEL'DOVICH EFFECT CLUSTERS ON THE CELESTIAL EQUATOR

We present the optical and X-ray properties of 68 galaxy clusters selected via the Sunyaev-Zel'dovich (SZ) effect at 148 GHz by the Atacama Cosmology Telescope (ACT). Our sample, from an area of 504 deg[sup 2] centered on the celestial equator, is divided into two regions. The main region uses 270 deg[sup 2] of the ACT survey that overlaps with the co-added ugriz imaging from the Sloan Digital Sky Survey (SDSS) over Stripe 82 plus additional near-infrared pointed observations with the Apache Point Observatory 3.5 m telescope. We confirm a total of 49 clusters to z [approximate] 1.3, of which 22 are new discoveries. We present the optical richness, photometric redshifts, and separation between the SZ position and the brightest cluster galaxy (BCG). We also present X-ray fluxes and luminosities from the ROSAT All Sky Survey which confirm that this is a massive sample.