|
| | | | |
| | | |
| Stat |
Members: 3645
Articles: 2'504'928
Articles rated: 2609
25 April 2024 |
|
| | | | |
|
Article overview
| |
|
|
Probing Galaxy Formation with He II Cooling Lines | | Yujin Yang
; Ann I. Zabludoff
; Romeel Davé
; Daniel J. Eisenstein
; Philip A. Pinto
; Neal Katz
; David H. Weinberg
; Elizabeth J. Barton
; | | Date: |
1 Sep 2005 | | Subject: | astro-ph | | Affiliation: | U of Arizona), Neal Katz (UMass), David H. Weinberg (Ohio State), Elizabeth J. Barton (UC Irvine | | Abstract: | Using high resolution cosmological simulations, we study hydrogen and helium gravitational cooling radiation. We focus on the HeII cooling lines, which arise from gas with a different temperature history (T_max ~ 10^5K) than HI line emitting gas. We examine whether three major atomic cooling lines, HI 1216A, HeII 1640A and HeII 304A are observable, finding that HI 1216A and HeII 1640A cooling emission at z=2-3 are potentially detectable with deep narrow band (R>100) imaging and/or spectroscopy from the ground. While the expected strength of HI 1216A cooling emission depends strongly on the treatment of the self-shielded phase of the IGM in the simulations, our predictions for the HeII 1640A line are more robust because the HeII 1640A emissivity is negligible below T~10^4.5 K and less sensitive to the UV background. Although HeII 1640A cooling emission is fainter than HI 1216A by at least a factor of 10 and, unlike HI 1216A, might not be resolved spatially with current observational facilities, it is more suitable to study gas accretion in the galaxy formation process because it is optically thin and less contaminated by the recombination lines from star-forming galaxies. The HeII 1640A line can be used to distinguish among mechanisms for powering the so-called "Lyman alpha blobs" -- including gravitational cooling radiation, photoionization by stellar populations, and starburst-driven superwinds -- because (1) HeII 1640A emission is limited to very low metallicity (log(Z/Z_sun) < -5.3) and Population III stars, and (2) the blob’s kinematics are probed unambiguously through the HeII 1640A line width, which, for cooling radiation, is narrower (sigma < 400 km/s) than typical wind speeds. | | Source: | arXiv, astro-ph/0509007 | | 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