Primordial gas cooling behind shock waves in merging halos
| dc.creator | Vasiliev, E. O. | |
| dc.creator | Shchekinov, Yu. A. | |
| dc.date | 2006-04-19 | |
| dc.date | 2006-04-21 | |
| dc.date.accessioned | 2026-07-07T07:04:42Z | |
| dc.date.available | 2026-07-07T07:04:42Z | |
| dc.description | 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 $f_{\rm c}\sim 10^{-3}$ for dark halos of $M=5\times 10^7\msun$ to $\sim 0.1$ for halos with $M=10^8\msun$ 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 $M\gg 10^8\msun$ 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 H$_2$. We argue that extremely metal-poor low-mass stars in the Milky Way may have been formed from primordial gas behind such shocks. | |
| dc.description | 17 pages, 5 figures, submitted in New Astronomy, reference list extended | |
| dc.identifier | https://arxiv.org/abs/astro-ph/0604403 | |
| dc.identifier | http://arxiv.org/abs/astro-ph/0604403 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/109411 | |
| dc.subject | Astrophysics | |
| dc.title | Primordial gas cooling behind shock waves in merging halos | |
| dc.type | text |