posted on 2024-08-06, 11:50authored byCaroline M.S. Straatman, Arjen Van Der Wel, Rachel Bezanson, Camilla Pacifici, Anna Gallazzi, Po Feng Wu, Kai Noeske, Ivana Barišić, Eric F. Bell, Gabriel B. Brammer, Joao Calhau, Priscilla Chauke, Marijn Franx, Josha Van Houdt, Ivo LabbeIvo Labbe, Michael V. Maseda, Juan C. Munoz-Mateos, Adam Muzzin, Jesse Van De Sande, David Sobral, Justin S. Spilker
We present the second data release of the Large Early Galaxy Astrophysics Census (LEGA-C), an ESO 130-night public spectroscopic survey conducted with VIMOS on the Very Large Telescope. We release 1988 spectra with typical continuum S/N similar or equal to 20 angstrom(-1) of galaxies at 0.6 less than or similar to z less than or similar to 1.0, each observed for similar to 20 hr and fully reduced with a custom-built pipeline. We also release a catalog with spectroscopic redshifts, emission-line fluxes, Lick/IDS indices, and observed stellar and gas velocity dispersions that are spatially integrated quantities, including both rotational motions and genuine dispersion. To illustrate the new parameter space in the intermediate-redshift regime probed by LEGA-C, we explore relationships between dynamical and stellar population properties. The star-forming galaxies typically have observed stellar velocity dispersions of similar to 150 km s(-1) and strong H delta absorption (H delta(A) similar to 5 angstrom), while passive galaxies have higher observed stellar velocity dispersions (similar to 200 km s(-1)) and weak H delta absorption (H delta(A) similar to 0 angstrom). Strong [O III] 5007/H beta ratios tend to occur mostly for galaxies with weak H delta(A) or galaxies with higher observed velocity dispersion. Beyond these broad trends, we find a diversity of possible combinations of rest-frame colors, absorption-line strengths, and emission-line detections, illustrating the utility of spectroscopic measurements to more accurately understand galaxy evolution. By making the spectra and value-added catalogs publicly available we encourage the community to take advantage of this very substantial investment in telescope time provided by ESO.
Funding
Hector: a revolutionary survey machine to discover how galaxies formed