Star Formation History and Stellar Metallicity Distribution in a Cold Dark Matter Universe
Abstract
We study star formation history and stellar metallicity distribution in galaxies in a Lambda cold dark matter universe using a hydrodynamic cosmological simulation. Our model predicts star formation rate declining in time exponentially from an early epoch to the present with the time-scale of 6 Gyr, which is consistent with the empirical Madau plot with modest dust obscuration. Star formation in L^* galaxies continues intermittently to the present also with an exponentially declining rate of a similar time-scale, whereas in small galaxies star formation ceases at an early epoch. The mean age of the extant stars decreases only slowly with increasing redshift, and exceeds 1 Gyr at z=3. Normal galaxies contain stars with a wide range of metallicity and age: stars formed at z<1 have metallicity of 0.1-1.0 Zsun, while old stars take a wide range of values from 10^{-6} Zsun to 3.0 Zsun. The mean metallicity of normal galaxies is in the range 0.1-1.0 Zsun. Dwarf galaxies that contain only old stars have a wide range of mean metallicity (10^{-4}-1.0 Zsun), but on average they are metal deficient compared with normal galaxies.
Keywords
Cite
@article{arxiv.astro-ph/0011472,
title = {Star Formation History and Stellar Metallicity Distribution in a Cold Dark Matter Universe},
author = {Kentaro Nagamine and Masataka Fukugita and Renyue Cen and Jeremiah P. Ostriker},
journal= {arXiv preprint arXiv:astro-ph/0011472},
year = {2009}
}
Comments
8 pages, 5 figures, emulateapj style. Accepted version in ApJ. More emphasis on the comparison with observations