The 2M++ galaxy redshift catalogue

Abstract

Peculiar velocities arise from gravitational instability, and thus are linked to the surrounding distribution of matter. In order to understand the motion of the Local Group with respect to the Cosmic Microwave Background, a deep all-sky map of the galaxy distribution is required. Here we present a new redshift compilation of 69~160 galaxies, dubbed 2M++, to map large-scale structures of the Local Universe over nearly the whole sky, and reaching depths of K <= 12.5, or 200 Mpc/h. The target catalogue is based on the Two-Micron-All-Sky Extended Source Catalog (2MASS-XSC). The primary sources of redshifts are the 2MASS Redshift Survey, the 6dF galaxy redshift survey and the Sloan Digital Sky Survey (DR7). We assess redshift completeness in each region and compute the weights required to correct for redshift incompleteness and apparent magnitude limits, and discuss corrections for incompleteness in the Zone of Avoidance. We present the density field for this survey, and discuss the importance of large-scale structures such as the Shapley Concentration.Comment: 19 pages, 15 figures, 6 tables, submitted to MNRA

Galaxy groups in the low-redshift Universe

“…For galaxies that have spectroscopic redshifts from the 6dFGS catalog, we assign the 6dF redshift. We also find redshifts for 1, 533 galaxies from the 2M++ galaxy redshift catalogue (2M++; Lavaux & Hudson 2011), which are originally from the NED. For galaxies without spectroscopic redshifts available, we assign redshifts of their nearest neighbors or from the 2MPZ in the same way as for the 2MRS described above.…”

“…The term SQ(z) is not needed when using extrapolated total magnitudes. We follow Lavaux & Hudson (2011) to model KQ(z), EQ(z), and SQ(z), and correct the values of MQ of individual galaxies to redshift z = 0.1. For nearby galaxies that have negative recession velocities in the CMB rest-frame (a total of 25 galaxies in the 2MRS catalog), we adopt distances from 'EDD distances' available at the Extragalactic Distance Database (EDD; Tully et al 2009) to calculate the absolute magnitudes.…”

“…Goto 2005; Berlind et al 2006). Lavaux & Hudson (2011) applied the FoF group finder to their own compilation combining the 2MRS, SDSS and Six Degree Field Galaxy Survey (6dFGS).…”

Unmasking the masked Universe: the 2M++ catalogue through Bayesian eyes

“…In this work we follow a similar procedure as described in and more recently in , by applying the BORG algorithm to the 2M++ galaxy compilation (Lavaux & Hudson 2011). The 2M++ is a superset of the 2MASS Redshift Survey (2MRS, Huchra et al 2012), with a greater depth and a higher sampling than the IRAS Point Source Catalogue Redshift Survey (PSCZ, Saunders et al 2000).…”

“…To have the largest, deepest and cleanest galaxy redshift compilation we propose to use the 2M++ (Lavaux & Hudson 2011) galaxy compilation. This survey offers a near full sky coverage at a magnitude K 2M++ 11.5 and above 50% coverage for K 2M++ 12.5.…”