Quick Search:

uzh logo
Browse by:

Zurich Open Repository and Archive

Maintenance: Tuesday, 5.7.2016, 07:00-08:00

Maintenance work on ZORA and JDB on Tuesday, 5th July, 07h00-08h00. During this time there will be a brief unavailability for about 1 hour. Please be patient.

Permanent URL to this publication: http://dx.doi.org/10.5167/uzh-34355

Feldmann, R; Carollo, C M; Mayer, L; Renzini, A; Lake, G; Quinn, T (2010). The evolution of central group galaxies in hydrodynamical simulations. Astrophysical Journal, 709(1):218-240.

Accepted Version
PDF (Accepted manuscript, Version 2)
View at publisher
Accepted Version
PDF (Accepted manuscript, Version 1)


We trace the evolution of central galaxies in three ~1013 M sun galaxy groups simulated at high resolution in cosmological hydrodynamical simulations. In all three cases, the evolution in the group potential leads, at z = 0, to central galaxies that are massive, gas-poor early-type systems supported by stellar velocity dispersion and which resemble either elliptical or S0 galaxies. Their z ~ 2-2.5 main progenitors are massive (M * ~ (3-10) × 1010 M sun), star-forming (20-60 M sun yr-1) galaxies which host substantial reservoirs of cold gas (~5 × 109 M sun) in extended gas disks. Our simulations thus show that star-forming galaxies observed at z ~ 2 are likely the main progenitors of central galaxies in galaxy groups at z = 0. At z ~ 2 the stellar component of all galaxies is compact, with a half-mass radius <1 kpc. The central stellar density stays approximatively constant from such early epochs down to z = 0. Instead, the galaxies grow inside out, by acquiring a stellar envelope outside the innermost ~2 kpc. Consequently the density within the effective radius decreases by up to 2 orders of magnitude. Both major and minor mergers contribute to most (70+20 -15%) of the mass accreted outside the effective radius and thus drive an episodical evolution of the half-mass radii, particularly below z = 1. In situ star formation and secular evolution processes contribute to 14+18 -9% and 16+6 -11%, respectively. Overall, the simulated galaxies grow by a factor ~4-5 in mass and size since redshift z ~ 2. The short cooling time in the center of groups can foster a "hot accretion" mode. In one of the three simulated groups this leads to a dramatic rejuvenation of the central group galaxy at z < 1, affecting its morphology, kinematics, and colors. This episode is eventually terminated by a group-group merger. Mergers also appear to be responsible for the suppression of cooling flows in the other two groups. Passive stellar evolution and minor galaxy mergers gradually restore the early-type character of the central galaxy in the cooling flow group on a timescale of ~1-2 Gyr. Although the average properties of central galaxies may be set by their halo masses, our simulations demonstrate that the interplay between halo mass assembly, galaxy merging, and gas accretion has a substantial influence on the star formation histories and z = 0 morphologies of central galaxies in galaxy groups.


62 citations in Web of Science®
59 citations in Scopus®
Google Scholar™



97 downloads since deposited on 02 Mar 2011
32 downloads since 12 months

Detailed statistics

Additional indexing

Item Type:Journal Article, refereed, original work
Communities & Collections:07 Faculty of Science > Institute for Computational Science
Dewey Decimal Classification:530 Physics
Date:January 2010
Deposited On:02 Mar 2011 09:56
Last Modified:05 Apr 2016 14:09
Publisher:Institute of Physics Publishing
Publisher DOI:10.1088/0004-637X/709/1/218
Related URLs:http://arxiv.org/abs/arXiv:0906.3022

Users (please log in): suggest update or correction for this item

Repository Staff Only: item control page