Hostname: page-component-78c5997874-dh8gc Total loading time: 0 Render date: 2024-11-10T16:47:19.590Z Has data issue: false hasContentIssue false
  • English
  • Français

Cosmic Helium Production

Published online by Cambridge University Press:  05 March 2013

Chris Flynn
Chris Flynn*
Affiliation:
Centre for Astrophysics Supercomputing, Swinburne University, Hawthorn VIC 3122, Australia
*
3E-mail: cflynn@oj287.astro.utu.fi
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

K-dwarfs are very long lived, slowly evolving stars, so that their present day helium Y and metal content (metallicity Z) is essentially the same as when they were born. K-dwarfs thus contain a fossil record of the amount of helium and metals which has been produced in successive stellar generations over the lifetime of the Galaxy. We here estimate the amount of helium compared to the amount of metals produced via stellar fusion (Δ Y/ΔZ). We use K-dwarfs in the Hipparcos catalogue for which accurate metallicities and luminosities are available. By including recently measured K-dwarfs with super-solar metallicities we are able to obtain a very significant improvement on previous studies. The best fitting value is ΔY/ΔZ = 2.4 ± 0.4 at the 68% confidence level. Values as low as 1 or as high as 4 are excluded with more than 99% confidence.

Keywords

Galaxy: abundancesGalaxy: evolution
Type
Research Article
Information
Publications of the Astronomical Society of Australia , Volume 21 , Issue 2: The Fifth Workshop on Galactic Chemodynamics , 2004 , pp. 126 - 128
Copyright
Copyright © Astronomical Society of Australia 2004

References

Alexander, D. R., & Ferguson, J. W. 1994, ApJ, 437, 879 Google Scholar
Barger, V., Kneller, J. P., Lee, H.-S., Marfatia, D., & Steigman, G. 2003, Phys. Lett., B 566, 8 CrossRefGoogle Scholar
Chaboyer, B., Demarque, P., Kernan, P. J., & Krauss, L. M. 1998, ApJ, 494, 96 Google Scholar
Feltzing, S., & Gonzalez, G. 2001, A&A, 367, 253 Google Scholar
Fernandes, J., Lebreton, Y., & Baglin, A. 1996, A&A, 311 Google Scholar
Flynn, C., & Morell, O. 1997, MNRAS, 286, 617 Google Scholar
Iglesias, C. A., & Rogers, F. J. 1996, ApJ, 464, 943 CrossRefGoogle Scholar
Jimenez, R., Flynn, C., MacDonald, J., & Gibson, B. 2002, Science, 299, 1552 Google Scholar
Kotoneva, E., Flynn, C., & Jimenez, R. 2002, MNRAS, 335, 1147 Google Scholar
Luridiana, V. 2002, in Proc. 37th Moriond Astrophysics Meeting.Google Scholar
Mihalas, D. 1978, Stellar Atmospheres (San Francisco: WH Freeman)Google Scholar
Pagel, B. E. J., & Portinari, L. 1998, MNRAS, 298, 747 Google Scholar
Peimbert, M., Peimbert, A., Luridiana, V., & Ruiz, M. T. 2002, in Star Formation Through Time, eds. E. Perez, R. M. Gonzalez Delgado, & G. Tenorio-Tagle (San Francisco: ASP), vol. 297, p. 81 Google Scholar
Perrin, M.-N., de Strobel, G. C., Cayrel, R., & Hejlesen, P. M. 1977, A&A, 54, 779 Google Scholar
Thorén, P., & Feltzing, S. 2000, A&A, 363, 692 Google Scholar
Tomkin, J., & Lambert, D. L. 1999, ApJ, 523, 234 Google Scholar
Trotta, R., & Hansen, S. 2004, Phys. Rev. D, 69, 023509Google Scholar