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Uncertainties in nebular helium abundances

Published online by Cambridge University Press:  23 April 2010

Evan D. Skillman
Evan D. Skillman*
Affiliation:
Astronomy Department, University of Minnesota, 116 Church St. SE, Minneapolis, MN, USA email: [email protected]
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Abstract

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Efforts to determine the primordial helium abundance via observations of metal poor HII regions have been limited by significant uncertainties. Because of a degeneracy between the solutions for density and temperature, the precision of the helium abundance determinations is limited. Spectra from the literature are used to show the effects of new atomic data and to demonstrate the challenges of determining precise He abundances. Several suggestions are made for meeting these challenges.

Keywords

nucleosynthesisabundancescosmological parametersearly universeISM: HII regions
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 5 , Symposium S268: Light Elements in the Universe , November 2009 , pp. 113 - 118
Copyright
Copyright © International Astronomical Union 2010

References

Benjamin, R. A., Skillman, E. D., & Smits, D. P. 1999, ApJ, 514, 307CrossRefGoogle Scholar
Davidson, K. & Kinman, T. D. 1985, ApJS, 58, 321CrossRefGoogle Scholar
Izotov, Y. I. & Thuan, T. X. 1998, ApJ, 500, 188CrossRefGoogle Scholar
Izotov, Y. I., Thuan, T. X., & Stasinska, G. 2007, ApJ, 662, 15 (ITS07)CrossRefGoogle Scholar
Luridiana, V., Peimbert, A., Peimbert, M., & Cerviño, M. 2003, ApJ, 592, 846CrossRefGoogle Scholar
Olive, K. A. & Skillman, E. D. 2001, New Astronomy, 6, 119CrossRefGoogle Scholar
Olive, K. A. & Skillman, E. D. 2004, ApJ, 617, 29CrossRefGoogle Scholar
Peimbert, M., Luridiana, V., & Peimbert, A. 2007, ApJ, 666, 636 (PLP07)CrossRefGoogle Scholar
Peimbert, M., Peimbert, A., & Ruiz, M. T. 2000, ApJ, 541, 688CrossRefGoogle Scholar
Porter, R. L., Ferland, G. J., & MacAdam, K. B. 2007, ApJ, 657, 327 (PFM)CrossRefGoogle Scholar
Skillman, E. D. & Kennicutt, R. C. 1993, ApJ, 411, 655CrossRefGoogle Scholar
Skillman, E. D., Terlevich, E., & Terlevich, R. 1998, Spa. Sci. Rev., 84, 105CrossRefGoogle Scholar
Stasińska, G. & Izotov, Y. I. 2001, A&A, 378, 817Google Scholar