Seven Problems Related to the Determination of the Primordial Helium Abundance

Bibcode
2003ASPC..297...81P
Peimbert, Manuel; Peimbert, Antonio; Luridiana, Valentina; Ruiz, María Teresa
Referencia bibliográfica

Star Formation Through Time, ASP Conference Proceedings, Vol. 297, held 24-28 September 2002 in Granada, Spain. Edited by Enrique Perez, Rosa M. Gonzalez Delgado and Guillermo Tenorio-Tagle. ISBN: 1-58381-144-3, 2003, p.81

Fecha de publicación:
0
2003
Número de autores
4
Número de autores del IAC
0
Número de citas
20
Número de citas referidas
14
Descripción
Recent advances on the quest to determine the primordial or pregalactic helium abundance, Yp, are reviewed. There are seven problems affecting the He/H abundance determinations of H II regions that are briefly discussed: the underlying absorption lines in the observed spectra, the ionization, temperature, and density structures of each object, the collisional contribution to the intensity of the He I and H I lines, the optical thickness of the He I lines, and the extrapolation to derive Yp based on the Y and O/H values.
Tipo
Sin árbitro

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