Open AccessModelling the number counts of early‐type galaxies by pure luminosity evolution
Author(s) -
He Ping,
Zhang YuanZhong
Publication year - 1998
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.1365-8711.1998.01649.x
Subject(s) - physics , astrophysics , redshift , galaxy , luminosity , hubble deep field , elliptical galaxy , astronomy , galaxy formation and evolution , hubble ultra deep field , hubble space telescope , star formation
In this paper, we explore the plausible luminosity evolution of early‐type galaxies in different cosmological models by constructing a set of pure luminosity evolution (PLE) models via the choices of the star‐formation rate (SFR) parameters and formation redshift z f of galaxies, with the observational constraints derived from the Hubble Space Telescope ( HST ) morphological number counts for elliptical and S0 galaxies of the Medium Deep Survey (MDS) and the Hubble Deep Field (HDF). We find that the number counts of early‐type galaxies can be explained by the pure luminosity evolution models, without invoking exotic scenarios such as merging or introducing an additional population, but the evolution should be nearly passive, with a high z f assumed. The conclusion is valid in all of the three cosmological models we adopt in this paper. We also present the redshift distributions for three bins of observed magnitudes in the F814w passband, to show the redshift at which the objects that dominate the counts at a given magnitude may be found. The predictions of the redshift distribution of 22.5 < b j < 24.0 are also presented for comparison with future data.