Gas Accretion via Lyman Limit Systems [chapter]

Nicolas Lehner
2017 Astrophysics and Space Science Library  
In cosmological simulations, a large fraction of the partial Lyman limit systems (pLLSs; 162) redshifts. Here I discuss unambiguous evidence for metal-poor gas at all z probed by the pLLSs and LLSs. At z<1, all the pLLSs and LLSs so far studied are located in the CGM of galaxies with projected distances <100-200 kpc. Regardless of the exact origin of the low-metallicity pLLSs/LLSs, there is a significant mass of cool, dense, low-metallicity gas in the CGM that may be available as fuel for
more » ... uing star formation in galaxies over cosmic time. As such, the metal-poor pLLSs and LLSs are currently among the best observational evidence of cold, metal-poor gas accretion onto galaxies.
doi:10.1007/978-3-319-52512-9_6 fatcat:zzeomypgk5f6fajy5zmteb5wwi