ECO: the Environmental COntext catalog
The ECO catalog (Moffett et al. 2015) is a purely archival, volume-limited data set designed to complement RESOLVE by performing a similar census within an order of magnitude larger volume (>400,000 cubic Mpc). ECO shares RESOLVE's photometric pipelines and environment metrics. Stellar and HI mass estimation are also harmonized with RESOLVE. However, ECO offers no new optical or radio spectroscopy, except where it overlaps RESOLVE. Thus ECO is ideally suited to studies of environment and stellar populations, but it lacks kinematic data and includes only limited 21cm data, which we supplement using the photometric gas fractions technique (Eckert et al. 2015a) to provide a full set of HI mass estimates. ECO provides a more complete census of galaxies than found in the SDSS redshift survey (to the same limit) but is still less complete than RESOLVE. At present, ECO has only one large A-semester footprint, but a B-semester extension of ECO is in preparation.
The Environmental COntext (ECO) catalog. Each dot is a galaxy with group redshift between cz=3000-7000 km/s (a 470 km/s buffer is used to identify fingers of God). Color shows group halo masses from abundance matching. Black cross-hatch indicates regions of overlap with public ALFALFA 21cm data. Red dashed lines surround the RESOLVE-A footprint.