2016/04/30 by Mark Dijkstra, Max Gronke, Max Grönke +1 · 2 citations
Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Star Formation Studies #Galaxies: Formation, Evolution, Phenomena #Galaxy #Hydrogen line #Physics #Radiative transfer #Redshift #Reionization #astro-ph.CO #astro-ph.GA
paper · pdf · doi:10.3847/0004-637x/828/2/71
11 pages, 5 figures, ApJ in press. Added section on delayed escape of Lya, clarified model description and motivation. Added references
openalex created_date 2016/06/24 · arxiv created 2016/07/15 · openalex publication_date 2016/09/02 · arxiv updated 2016/09/21 · openalex updated_date 2026/08/05
ABSTRACT The escape of ionizing Lyman continuum (LyC) photons requires the existence of low- N H i sightlines, which also promote escape of Ly α . We use a suite of 2500 Ly α Monte-Carlo radiative transfer simulations through models of dusty, clumpy interstellar (“multiphase”) media from Gronke & Dijkstra, and compare the escape fractions of Ly α ( ) and LyC radiation ( ). We find that and are correlated: galaxies with a low consistently have a low , while galaxies with a high exhibit a large dispersion in . We argue that there is increasing observational evidence that Ly α escapes more easily from UV-faint galaxies. The correlation between and then implies that UV-faint galaxies contribute more to the ionizing background than implied by the faint-end slope of the UV luminosity function. In multiphase gases, the ionizing escape fraction is most strongly affected by the cloud covering factor, f cl , which implies that is closely connected to the observed Ly α spectral line shape. Specifically, LyC-emitting galaxies typically having narrower, more symmetric line profiles. This prediction is qualitatively similar to that for “shell models.”