|
| | | | |
| | | |
| Stat |
Members: 3645
Articles: 2'504'585
Articles rated: 2609
25 April 2024 |
|
| | | | |
|
Article overview
| |
|
|
The Era of Reionization | | Piero Madau
; | | Date: |
28 Dec 2002 | | Subject: | astro-ph | | Affiliation: | University of California Santa Cruz | | Abstract: | In popular cold dark matter cosmological scenarios, stars may have first appeared in significant numbers around a redshift of 10 or so, as the gas within protogalactic halos with virial temperatures in excess of 20,000 K (corresponding to masses comparable to those of present-day dwarf ellipticals) cooled rapidly due to atomic processes and fragmented. It is this `second generation’ of subgalactic stellar systems, aided perhaps by an early population of accreting black holes in their nuclei, which may have generated the ultraviolet radiation and mechanical energy that ended the cosmic ``dark ages’’ and reheated and reionized most of the hydrogen in the universe by a redshift of 6. The detailed history of the universe during and soon after these crucial formative stages depends on the power-spectrum of density fluctuations on small scales and on a complex network of poorly understood `feedback’ mechanisms, and is one of the missing link in galaxy formation and evolution studies. The astrophysics of the epoch of first light is recorded in the thermal state, ionization degree, and chemical composition of the intergalactic medium, the main repository of baryons at high redshifts. | | Source: | arXiv, astro-ph/0212555 | | Services: | Forum | Review | PDF | Favorites | |
|
|
No review found.
Did you like this article?
Note: answers to reviews or questions about the article must be posted in the forum section.
Authors are not allowed to review their own article. They can use the forum section.
browser Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)
|
| |
|
|
|
|
News, job offers and information for researchers and scientists:
| |
REGISTER