Open AccessCosmological constraints from the masses and abundances of L * galaxies
Author(s) -
Seljak U.
Publication year - 2002
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.1365-8711.2002.05779.x
Subject(s) - physics , astrophysics , galaxy , halo , dark matter , virial mass , luminosity function , dark matter halo , galaxy formation and evolution , astronomy , halo mass function , galactic halo , luminosity , virial theorem , spectral density , statistics , mathematics
We place limits on the mean density of the Universe (Ω m ) and the effective slope of the linear power spectrum around a megaparsec scale ( n eff ) by comparing the universal mass function to the observed luminosity function. Numerical simulations suggest that the dark matter halo mass function at small scales depends only on Ω m ( n eff + 3) independent of the overall power spectrum normalization. Matching the halo abundance to the observed luminosity function requires knowledge of the relation between the virial mass and luminosity (separately for early‐ and late‐type galaxies) and the fraction of galaxies that resides in larger haloes such as groups and clusters, all of which can be extracted from the galaxy–galaxy lensing. We apply the recently derived values from the Sloan Digital Sky Survey and find Ω m ( n eff + 3) = (0.15 ± 0.05)/(1 − f dh ) , where f dh accounts for the possibility that some fraction of haloes may be dark or without a bright central galaxy. A model with Ω m = 0.25 and primordial n = 0.8 or with Ω m = 0.2 and n = 1 agrees well with these constraints even in the absence of dark haloes, although with the current data somewhat higher values for Ω m and n are also acceptable.