Temperature Fluctuations,H II Region Abundances,and Primordial Helium |
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Authors: | Steigman Gary Viegas Sueli M. Gruenwald Ruth |
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Affiliation: | (1) Departments of Physics and Astronomy, The Ohio State University, Columbus, OH 43210, USA;(2) Instituto Astronômico e Geofísico, Universidade de São Paulo, São Paulo, S.P, 04301-904, BRASIL |
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Abstract: | There is evidence for temperature fluctuations in Planetary Nebulae and in some Galactic H II regions. If such fluctuations occur in the low metallicity, extragalactic H II regions used to probe the primordial helium abundance, the derived 4He mass fraction, YP, could be systematically different from the true primordial value. Although this effect could be large, there are no data which allow us to estimate the size of the temperature fluctuations for the extragalactic H II regions. Therefore, we have explored this effect via Monte Carlo simulations of the data in which the abundances derived from a fiducial data set are modified by T chosen from a distribution with 0 T Tmax where Tmax is varied from 500 K to 4000 K. |
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Keywords: | Temperature Fluctuations H II Region Abundances Primordial Helium |
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