2006/04/19 by E. O. Vasiliev, Vasiliev, E. O., Yuri A. Shchekinov +1
Physics and Astronomy · #Astrophysics (astro-ph) #Astrophysics and Star Formation Studies #Cosmology and Gravitation Theories #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena
paper · pdf · doi:10.48550/arxiv.astro-ph/0604403
openalex publication_date 2006/04/19 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We investigate thermal regime of the baryons behind shock waves arising in the process of virialization of dark matter halos. We find a fraction of the shocked gas cooled by radiation of HD molecules down to the temperature of the cosmic microwave background (CMB): this fraction increases sharply from about f\rm c∼ 10-3 for dark halos of M=5× 107\msun to ∼ 0.1 for halos with M=108\msun at z=10. We show, however, that further increase of the mass does not lead to a significant growth of f\rm c -- the assymptotic value for M≫ 108\msun is of 0.2. We estimate star formation rate associated with such shock waves, and show that it can be a small but not negligible fraction of the star formation connected with cooling by HI and H2. We argue that extremely metal-poor low-mass stars in the Milky Way may have been formed from primordial gas behind such shocks.