Open AccessPopulating a cluster of galaxies – I. Results at
Author(s) -
Springel Volker,
White Simon D. M.,
Tormen Giuseppe,
Kauffmann Guinevere
Publication year - 2001
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2001.04912.x
Subject(s) - physics , astrophysics , elliptical galaxy , velocity dispersion , galaxy cluster , brightest cluster galaxy , dwarf galaxy problem , galaxy formation and evolution , astronomy , lenticular galaxy , dark matter halo , dwarf spheroidal galaxy , dark matter , dwarf galaxy , peculiar galaxy , galaxy , halo
We simulate the assembly of a massive rich cluster and the formation of its constituent galaxies in a flat, low‐density universe. Our most accurate model follows the collapse, the star formation history and the orbital motion of all galaxies more luminous than the Fornax dwarf spheroidal, while dark halo structure is tracked consistently throughout the cluster for all galaxies more luminous than the SMC. Within its virial radius this model contains about dark matter particles and almost 5000 distinct dynamically resolved galaxies. Simulations of this same cluster at a variety of resolutions allow us to check explicitly for numerical convergence both of the dark matter structures produced by our new parallel N ‐body and substructure identification codes, and of the galaxy populations produced by the phenomenological models we use to follow cooling, star formation, feedback and stellar aging. This baryonic modelling is tuned so that our simulations reproduce the observed properties of isolated spirals outside clusters. Without further parameter adjustment our simulations then produce a luminosity function, a mass‐to‐light ratio, luminosity, number and velocity dispersion profiles, and a morphology–radius relation which are similar to those observed in real clusters. In particular, since our simulations follow galaxy merging explicitly, we can demonstrate that it accounts quantitatively for the observed cluster population of bulges and elliptical galaxies.