Science-advisor
REGISTER info/FAQ
Login
username
password
     
forgot password?
register here
 
Research articles
  search articles
  reviews guidelines
  reviews
  articles index
My Pages
my alerts
  my messages
  my reviews
  my favorites
 
 
Stat
Members: 3643
Articles: 2'488'730
Articles rated: 2609

29 March 2024
 
  » arxiv » astro-ph/0011303

 Article overview


Probing the First Stars with Hydrogen and Helium Recombination Emission
Jason Tumlinson ; Mark L. Giroux ; J. Michael Shull ;
Date 15 Nov 2000
Subject astro-ph
AbstractUnusual patterns of recombination emission from gas ionized by metal-free stars may distinguish early star-forming galaxies from their present-day counterparts. This pattern arises from the harder ionizing spectrum expected from metal-free stars, which strongly enhances the strength of He II recombination lines. Our calculations indicate that line fluxes of He II 1640 and 4686 are sufficiently large to be detected by narrowband and spectroscopic searches for high-redshift emission-line sources at redshift z ~ 5 using current instruments. An unknown fraction of Lya emitters may harbor low-metallicity or metal-free stars. As the predicted He II 1640 flux is comparable to and may exceed hydrogen Lya, searches for high-redshift galaxies should consider He II recombination lines as possible identifications for single emission lines in observed spectra. Spectra of metal-free stars may show both H I and He II emission lines, improving the constraints on their redshift and identification. We assess the considerable uncertainties that affect our expectations for the detection and identification of true first-generation stars with present search techniques, including the role of stellar mass loss in spectral evolution and the confusion of ionization by primordial stellar sources and AGN in the early universe.
Source arXiv, astro-ph/0011303
Services Forum | Review | PDF | Favorites   
 
Visitor rating: did you like this article? no 1   2   3   4   5   yes

No review found.
 Did you like this article?

This article or document is ...
important:
of broad interest:
readable:
new:
correct:
Global appreciation:

  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 claudebot






ScienXe.org
» my Online CV
» Free


News, job offers and information for researchers and scientists:
home  |  contact  |  terms of use  |  sitemap
Copyright © 2005-2024 - Scimetrica