|
| | | | |
| | | |
| Stat |
Members: 3645
Articles: 2'506'133
Articles rated: 2609
26 April 2024 |
|
| | | | |
|
Article overview
| |
|
|
White Noise from Dark Matter: 21 cm Observations of Early Baryon Collapse | | Kathryn M. Zurek
; Craig J. Hogan
; | | Date: |
26 Mar 2007 | | Abstract: | In concordance cosmology, dark matter density perturbations generated by inflation lead to nonlinear, virialized minihalos, into which baryons collapse at redshift $z sim 20$. We survey here novel baryon evolution produced by a modification of the power spectrum from white noise density perturbations at scales below $k sim 10 h {Mpc}^{-1}$ (the smallest scales currently measured with the Lyman-$alpha$ forest). Exotic dark matter dynamics, such as would arise from scalar dark matter with a late phase transition (similar to an axion, but with lower mass), create such an amplification of small scale power. The dark matter produced in such a phase transition collapses into minihalos, with a size given by the dark matter mass within the horizon at the phase transition. If the mass of the initial minihalos is larger than $sim 10^{-3} M_odot$, the modified power spectrum is found to cause widespread baryon collapse earlier than standard $Lambda$CDM, leading to earlier gas heating. It also results in higher spin temperature of the baryons in the 21 cm line relative to $Lambda$CDM at redshifts $z > 20$ if the mass of the minihalo is larger than $1 M_odot$. It is estimated that experiments probing 21 cm radiation at high redshift will contribute a significant constraint on dark matter models of this type for initial minihalos larger than $sim 10 M_odot$. Early experiments reaching to $zapprox 15$ will constrain minihalos down to $sim 10^3 M_odot$. | | Source: | arXiv, astro-ph/0703624 | | 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