cosmology : theory;
galaxies : formation;
large-scale structure of universe;
D O I:
10.1086/503163
中图分类号:
P1 [天文学];
学科分类号:
0704 ;
摘要:
I calculate the mass function evolution in a Lambda CDM model by means of the excursion set model and an improved version of the barrier shape obtained by Del Popolo & Gambera, which implicitly takes account of the total angular momentum acquired by the protostructure during evolution and of a nonzero cosmological constant. I compare the result with that of Reed et al., who used a high-resolution Lambda CDM numerical simulation to calculate the mass function of dark matter halos down to the scale of dwarf galaxies, back to a redshift of 15. I show that the mass function obtained in the present paper gives similar predictions to the Sheth & Tormen mass function but does not share its overprediction of extremely rare objects. The results confirm previous findings that the simulated halo mass function can be described solely by the variance of the mass distribution, and thus has no explicit redshift dependence.