2011/12/31 by Hidenobu Yajima, Yuexing Li, Qirong Zhu +3 · 1 citation
Physics and Astronomy · #Astronomy and Astrophysical Research #Dwarf galaxy #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy formation and evolution #Gamma-ray bursts and supernovae #Line (geometry) #Luminosity #Milky Way #Redshift #Star formation #astro-ph.CO #astro-ph.GA
paper · pdf · doi:10.1088/0004-637x/754/2/118
15 pages, 13 figures, accepted for publication in ApJ
arxiv created 2012/05/28 · openalex publication_date 2012/07/16 · arxiv updated 2015/06/03 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The Lyα emission has been observed from galaxies over a redshift span z ∼ 0–8.6. However, the evolution of high-redshift Lyα emitters (LAEs), and the link between these populations and local galaxies, remains poorly understood. Here, we investigate the Lyα properties of progenitors of a local L * galaxy by combining cosmological hydrodynamic simulations with three-dimensional radiative transfer calculations using the new ART 2 code. We find that the main progenitor (the most massive one) of a Milky-Way-like galaxy has a number of Lyα properties close to those of observed LAEs at z ∼ 2–6, but most of the fainter ones appear to fall below the detection limits of current surveys. The Lyα photon escape fraction depends sensitively on a number of physical properties of the galaxy, such as mass, star formation rate, and metallicity, as well as galaxy morphology and orientation. Moreover, we find that high-redshift LAEs show blueshifted Lyα line profiles characteristic of gas inflow, and that the Lyα emission by excitation cooling increases with redshift, and becomes dominant at z ≳ 6. Our results suggest that some observed LAEs at z ∼ 2–6 with luminosity of L Lyα ∼ 10 42 –10 43 erg s −1 may be similar to the main progenitor of the Milky Way at high redshift, and that they may evolve into present-day L * galaxies.