English

The cosmic production of Helium

Astrophysics 2009-11-07 v1

Abstract

We estimate the cosmic production rate of helium relative to metals (ΔY/ΔZ\Delta Y/\Delta Z) using K dwarf stars in the Hipparcos catalog with accurate spectroscopic metallicities. The best fitting value is ΔY/ΔZ=2.1±0.4\Delta Y/\Delta Z=2.1 \pm 0.4 at the 68% confidence level. Our derived value agrees with determinations from HII regions and with theoretical predictions from stellar yields with standard assumptions for the initial mass function. The amount of helium in stars determines how long they live and therefore how fast they will enrich the insterstellar medium with fresh material.

Keywords

Cite

@article{arxiv.astro-ph/0303179,
  title  = {The cosmic production of Helium},
  author = {Raul Jimenez and Chris Flynn and James MacDonald and Brad K. Gibson},
  journal= {arXiv preprint arXiv:astro-ph/0303179},
  year   = {2009}
}

Comments

Published in Science Mar 7 2003: 1552-1555