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Based on cosmological simulations, we model Lyman continuum emission from a sample of 11 high-redshift star forming galaxies spanning a mass range of a factor 20. Each of the 11 galaxies has been simulated both with a Salpeter and a Kroupa initial mass function (IMF). We find that the Lyman continuum (LyC) luminosity of an average star forming galaxy in our sample declines from z=3.6 to 2.4 due to the steady gas infall and higher gas clumping at lower redshifts, increasingly hampering the escape of ionizing radiation. The galaxy-to-galaxy variation of apparent LyC emission at a fixed redshift is caused in approximately equal parts by the intrinsic variations in the LyC emission and by orientation effects. The combined scatter of an order of magnitude can explain the variance in the far-UV spectra of high-redshift galaxies detected by Shapley et al. (2006). Our results imply that the cosmic galactic ionizing UV luminosity would be monotonically decreasing from z=3.6 to 2.4, curiously anti-correlated with the star formation rate in the smaller galaxies, which on average rises during this redshift interval.
Compact starburst galaxies are thought to include many or most of the galaxies from which substantial Lyman continuum emission can escape into the intergalactic medium. Li and Malkan (2018) used SDSS photometry to find a population of such starburst
If enough of their Lyman limit continuum escapes, star-forming galaxies could be significant contributors to the cosmic background of ionizing photons. To investigate this possibility, we obtained the first deep imaging in the far ultraviolet of elev
We have obtained the first complete ultraviolet (UV) spectrum of a strong Lyman continuum(LyC) emitter at low redshift -- the compact, low-metallicity, star-forming galaxy J1154+2443 -- with a Lyman continuum escape fraction of 46% discovered recentl
We propose to infer ionising continuum leaking properties of galaxies by looking at their Lyman-alpha line profiles. We carry out Lyman-alpha radiation transfer calculations in two models of HII regions which are porous to ionising continuum escape:
A large number of high-redshift galaxies have been discovered via their narrow-band Lya line or broad-band continuum colors in recent years. The nature of the escaping process of photons from these early galaxies is crucial to understanding galaxy ev