The Zurich Environmental Study of Galaxies in Groups along the Cosmic Web. I. Which Environment Affects Galaxy Evolution?

Carollo, C.M.; Cibinel, A.; Lilly, S.J.; Miniati, F.; Norberg, P.; Silverman, J.D.; van Gorkom, J.; Cameron, E.; Finoguenov, A.; Peng, Y.; Pipino, A.; Rudick, C.S.

Abstract

The Zurich Environmental Study (ZENS) is based on a sample of ~1500 galaxy members of 141 groups in the mass range ~1012.5-14.5 M ☉ within the narrow redshift range 0.05 < z < 0.0585. ZENS adopts novel approaches, described here, to quantify four different galactic environments, namely: (1) the mass of the host group halo; (2) the projected halo-centric distance; (3) the rank of galaxies as central or satellites within their group halos; and (4) the filamentary large-scale structure density. No self-consistent identification of a central galaxy is found in ~40% of <1013.5 M ☉ groups, from which we estimate that ~15% of groups at these masses are dynamically unrelaxed systems. Central galaxies in relaxed and unrelaxed groups generally have similar properties, suggesting that centrals are regulated by their mass and not by their environment. Centrals in relaxed groups have, however, ~30% larger sizes than in unrelaxed groups, possibly due to accretion of small satellites in virialized group halos. At M > 1010 M ☉, satellite galaxies in relaxed and unrelaxed groups have similar size, color, and (specific) star formation rate distributions; at lower galaxy masses, satellites are marginally redder in relaxed relative to unrelaxed groups, suggesting quenching of star formation in low-mass satellites by physical processes active in relaxed halos. Overall, relaxed and unrelaxed groups show similar stellar mass populations, likely indicating similar stellar mass conversion efficiencies. In the enclosed ZENS catalog, we publish all environmental diagnostics as well as the galaxy structural and photometric measurements described in companion ZENS papers II and III.

Citation

Carollo, C., Cibinel, A., Lilly, S., Miniati, F., Norberg, P., Silverman, J., …Rudick, C. (2013). The Zurich Environmental Study of Galaxies in Groups along the Cosmic Web. I. Which Environment Affects Galaxy Evolution?. Astrophysical Journal, 776(2), Article 71. https://doi.org/10.1088/0004-637x/776/2/71

• Journal Article Type: Article
• Publication Date: Oct 20, 2013
• Deposit Date: Jun 3, 2014
• Publicly Available Date: Jun 23, 2014
• Journal: Astrophysical Journal
• Print ISSN: 0004-637X
• Electronic ISSN: 1538-4357
• Publisher: American Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 776
• Issue: 2
• Article Number: 71
• DOI: https://doi.org/10.1088/0004-637x/776/2/71
• Keywords: Galaxies: evolution, Galaxies: formation, Galaxies: groups: general, Galaxies: star formation, Galaxies: stellar content, Galaxies: structure.
• Public URL: https://durham-repository.worktribe.com/output/1429512