| Popis: |
Explaining the nature of the Lyman Break Galaxies (LBGs) recently discovered [1,2] at redshift z∼3, is an exciting challenge for the paradigm of hierarchical structure formation. These galaxies are forming stars at a rate comparable to locally rare “starburst” galaxies [3], but are as luminous and numerous as local bright galaxies. In addition, the brightest LBGs have small emission line-widths [4], indicating viral masses of ∼1−5×1010 M⊙, however LBGs exhibit strong clustering, similar to the properties expected of the most massive (∼1012M⊙) dark matter halos [5–8] at this redshift. We explore a possible solution to these apparent paradoxes: that LBGs are a population of collision-driven starburst galaxies which are abundant due to an increased collision rate at high redshift [2,9]. We use high-resolution cosmological N-body simulations and a hierarchical halo finder to estimate the galaxy collision rate as a function of time in a popular cosmological model (ΛCDM). We find that appropriate collisions are... |
