Photoionization Models of Metal-poor Extragalactic H 0 Regions and the Primordial Helium Abundance
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
Luridiana, V. et al.
Advertised on:
9
2003