2025/12/08 by Gallazzi, Anna R., Zibetti, Stefano, van der Wel, Arjen +11
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics of Galaxies (astro-ph.GA) #Electrical and Electromagnetic Research #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena
paper · doi:10.48550/arxiv.2512.07952
openalex publication_date 2025/12/08 · openalex created_date 2025/12/11 · openalex updated_date 2026/07/28
We analyze stellar population properties of 552 galaxies at redshift 0.6=0.7 and masses >1010Msun. The downsizing trends observed locally were already in place 6 Gyr ago. We observe bimodal age distribution as a function of mass, transitioning around 1011Msun. No bimodality appears in the stellar metallicity-mass relation, which changes from steep to flat across 1010.8Msun. Similar trends emerge for age and metallicity with velocity dispersion, but with sharper transition from young to old around log(sigma)=2.3. Differences with respect to trens with stellar mass suggest that age primarily depends on velocity dispersion below and above the transition regime, while both stellar mass and velocity dispersion contribute to stellar metallicity. The catalogs of revised absorption index measurements for LEGA-C DR3 and inferred stellar population physical parameters will be released to public repositories. (Abridged)