THE 2MASS REDSHIFT SURVEY—DESCRIPTION AND DATA RELEASE

Abstract

We present the results of the 2MASS Redshift Survey (2MRS), a ten-year\nproject to map the full three-dimensional distribution of galaxies in the\nnearby Universe. The 2 Micron All-Sky Survey (2MASS) was completed in 2003 and\nits final data products, including an extended source catalog (XSC), are\navailable on-line. The 2MASS XSC contains nearly a million galaxies with Ks <=\n13.5 mag and is essentially complete and mostly unaffected by interstellar\nextinction and stellar confusion down to a galactic latitude of |b|=5 deg for\nbright galaxies. Near-infrared wavelengths are sensitive to the old stellar\npopulations that dominate galaxy masses, making 2MASS an excellent starting\npoint to study the distribution of matter in the nearby Universe.\n We selected a sample of 44,599 2MASS galaxies with Ks <= 11.75 mag and |b|>=5\ndeg (>= 8 deg towards the Galactic bulge) as the input catalog for our survey.\nWe obtained spectroscopic observations for 11,000 galaxies and used\npreviously-obtained velocities for the remainder of the sample to generate a\nredshift catalog that is 97.6% complete to well-defined limits and covers 91%\nof the sky. This provides an unprecedented census of galaxy (baryonic mass)\nconcentrations within 300 Mpc.\n Earlier versions of our survey have been used in a number of publications\nthat have studied the bulk motion of the Local Group, mapped the density and\npeculiar velocity fields out to 50 Mpc, detected galaxy groups, and estimated\nthe values of several cosmological parameters.\n Additionally, we present morphological types for a nearly-complete sub-sample\nof 20,860 galaxies with Ks < 11.25 mag and |b|>= 10 deg.\n