1998/02/13 by Limin Lu, W. L. W. Sargent, Lu, Limin +7 · 1 citation
Agricultural and Biological Sciences · Physics and Astronomy · #Astrophysics (astro-ph) #Astrophysics and Star Formation Studies #FOS: Physical sciences #Leaf Properties and Growth Measurement #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9802189
AASTEX, 46 pages, 4 tables, 5 figures, submitted to Astronomical Journal
arxiv created 1998/02/13 · openalex publication_date 1998/02/13 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We investigate the metal contents of Lyman-alpha clouds at 2.21014.5 cm-2. This result rules out the suggestion that a generation of Population III stars could have polluted the entire universe to a (nearly) uniform metallicity level of [C/H]=-2.5. Cosmological simulations involving gas hydrodynamics indicate that Lyman-alpha absorption with N(HI)>1014.5 cm-2 mostly occur in the filamentary gaseous regions surrounding and connecting collapsed objects, while those with N(HI)<1014 cm-2 are preferentially found in void regions further away from collapsed objects. These results, coupled with the simulation results of Ostriker and Gnedin (1996) and Gnedin and Ostriker (1997) for Pop III star formation and enrichment, strongly suggest that most of the heavy elements in Lyman-alpha clouds with N(HI)>1014.5 cm-2 (i.e., gas in the filaments) were probably prodcued in situ by Pop II stars, in the sense that they were either made by stars within the clouds or were ejected from nearby star-forming galaxies. Within this context, clouds with N(HI)<1014 cm-2 (i.e., gas in void regions) may only have e experienced pollution from Pop III stars.