Stellar Mass Function Of Lyman Break Galaxies: Theoretical Perspective

In the current paradigm of galaxy formation and evolution, galaxies form by gas cooling and condensation within dark halos. One of the most basic questions for galaxies is their distribution with different luminosities. Since galaxy luminosities in different wavelengths show their different properties, they are widely adopted to constrain theoretical models, especially at higher redshift because galaxies are in general more active there than local ones.Lyman Break Galaxies(LBGs) are colour-selected galaxies at redshift z³ basedon the UV-drop method suggested by Steidel, Pettini and Hamilton in 1995. LBGs are very bright in their rest-frame UV hence they are very active in star formation. Until now more than 1000 LBGs can be briefly summarized as follows. Under the'concordant' cosmogony with Ω_m=0.3, Ω(?)=0.7, and H₀ = 70 km s^1- Mpc^-1 thestar formation in LBGs haloes is quite efficient; a large fraction of all the gas in them can form stars on a time scale of about 10-20 percent of the Hubble time atredshift of 3, their typical star formation rate (SFR) is ⁵0 M (?) yr^-1 with thecommoving number density ²Ã—10^-3 h³ Mpc^-3 , which is comparable to the number density of local bright galaxies. They are strongly clustered in space with the comoving correlation length ³ h^-1 Mpc. They are very compact with a typicalhalf-light radius in UV about 1.5 h^-1 kpc . It is likely that these LBGs are theprogenitors of galactic bulges and faint ellipticals.Adopting the observational distributions of star formation rates and hlf-light radiiof Lyman Break Galaxies (LBGs) in the rest frame UV, we investigate empirically the predicted stellar mass function for LBGs. It is found that a peak exists at mass around 1.5×10¹⁰ M (?) for their stellar mass function and there have been significant amount of LBGs with stellar masses higher than 10¹¹ M(?) at z³.There should be...