2007/10/22 by Dawn K. Erb
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Galaxies: Formation, Evolution, Phenomena #astro-ph
paper · pdf · doi:10.1086/524727
7 pages, 3 figures. Accepted for publication in ApJ
arxiv created 2007/10/22 · openalex publication_date 2008/02/07 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
Motivated by the increasing use of the Kennicutt-Schmidt (K-S) star formation law to interpret observations of high-redshift galaxies, the importance of gas accretion to galaxy formation, and the recent observations of chemical abundances in galaxies at z ∼ 2-3, I use simple analytical models to assess the consistency of these processes of galaxy evolution with observations and with each other. I derive the time dependence of star formation implied by the K-S law and show that the sustained high star formation rates observed in galaxies at z ∼ 2-3 require the accretion of additional gas. A model in which the gas accretion rate is approximately equal to the combined star formation and outflow rates broadly reproduces the observed trends of star formation rate with galaxy age. Using an analytical description of chemical evolution, I also show that this model, further constrained to have an outflow rate roughly equal to the star formation rate, reproduces the observed mass-metallicity relation at z ∼ 2.