The Magellanic Clouds and the Primordial Helium Abundance
Astrophysics
2007-05-23 v1
Abstract
A new determination of the pregalactic helium abundance based on the Magellanic Clouds H II regions is discussed. This determination amounts to Yp = 0.2345 +- 0.0030 and is compared with those derived from giant extragalactic H II regions in systems with extremely low heavy elements content. It is suggested that the higher primordial value derived by other authors from giant H II region complexes could be due to two systematic effects: the presence of neutral hydrogen inside the helium Stromgren sphere and the presence of temperature variations inside the observed volume.
Cite
@article{arxiv.astro-ph/0002120,
title = {The Magellanic Clouds and the Primordial Helium Abundance},
author = {Manuel Peimbert Antonio Peimbert},
journal= {arXiv preprint arXiv:astro-ph/0002120},
year = {2007}
}
Comments
10 pages, 1 figure, IAU Symposium 198