Photoionization Models of Metal-poor Extragalactic H 0 Regions and the Primordial Helium Abundance

Bibcode
2003RMxAC..18...56L
Luridiana, V.; Peimbert, A.; Peimbert, M.
Bibliographical reference

The Eight Texas-Mexico Conference on Astrophysics (Eds. M. Reyes-Ruiz & E. Vázquez-Semadeni) Revista Mexicana de Astronomía y Astrofísica (Serie de Conferencias) Vol. 18, pp. 56-59 (2003) (http://www.astroscu.unam.mx/~rmaa/)

Advertised on:
9
2003
Number of authors
3
IAC number of authors
0
Citations
0
Refereed citations
0
Description
We discuss the effects of collisional enhancement of Balmer lines on the determination of the primordial helium abundance. To this aim, we present a photoionization model of the metal-poor extragalactic H 0 region SBS 0335-052. We show that the derived helium abundance (Y) of this H 0 region depends on the amount of collisional excitation affecting the Balmer lines, both directly (through an underestimation of the actual He/H ratio) and indirectly (through an overestimation of the interstellar reddening). We detail how each of these effects affects the derived value of Y.
Type
Non-refereed
Galaxies
H II regions

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