| | |
| | |
Stat |
Members: 3645 Articles: 2'501'711 Articles rated: 2609
19 April 2024 |
|
| | | |
|
Article overview
| |
|
Early Structure Formation and Reionization in a Cosmological Model with a Running Primordial Power Spectrum | Naoki Yoshida
; Aaron Sokasian
; Lars Hernquist
; Volker Springel
; | Date: |
28 May 2003 | Journal: | Astrophys.J. 598 (2003) 73-85 | Subject: | astro-ph | Affiliation: | CfA, NAOJ), Aaron Sokasian (CfA), Lars Hernquist (CfA), Volker Springel (MPA | Abstract: | (abridged) We study high redshift structure formation and reionization in a LCDM universe under the assumption that the spectral power index of primordial density fluctuations is a function of length scale. We adopt a particular formulation of the running spectral index (RSI) model as suggested by the recent WMAP data. While early structure forms hierarchically in the RSI model, the reduced power on small scales causes a considerable delay in the formation epoch of low mass (~ 10^6 Msun) ``mini-halos’’ compared to the LCDM model. The extremely small number of gas clouds in the RSI model indicates that reionization is initiated later than z<15, generally resulting in a smaller total Thomson optical depth than in the LCDM model. By carrying out radiative transfer calculations, we also study reionization by stellar populations formed in galaxies. Even with a top-heavy intial mass function representing an early population of massive stars and/or an extraordinarily high photon emission rate from galaxies, the total optical depth can only be as large as tau ~ 0.1 for reasonable models of early star-formation. The RSI model is thus in conflict with the large Thomson optical depth inferred by the WMAP satellite. | Source: | arXiv, astro-ph/0305517 | 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:
| |