Revised primordial helium abundance based on new atomic data
Por:
Peimbert M., Luridiana V., Peimbert A.
Publicada:
1 ene 2007
Resumen:
We have derived a primordial helium abundance of Yp = 0.2477 ± 0.0029, based on new atomic physics computations of the recombination coefficients of He I and of the collisional excitation of the H I Balmer lines together with observations and photoionization models of metal-poor extragalactic H II regions. The new atomic data increase our previous determination of Yp by 0.0086, a very significant amount. By combining our Yp result with the predictions made by the standard big bang nucleosynthesis model, we find a baryon-to-photon ratio, 77, in excellent agreement both with the ?-value derived by the primordial deuterium abundance value observed in damped Ly? systems and with the one obtained from the WMAP observations. © 2007. The American Astronomical Society. All rights reserved.
Filiaciones:
Peimbert M.:
Instituto de Astronomía, Universidad Nacional Autónoma de México, México 04510 D.F., Mexico
Luridiana V.:
Instituto de Astrofísica de Andalucía (CSIC), 18008 Granada, Spain
Peimbert A.:
Instituto de Astronomía, Universidad Nacional Autónoma de México, México 04510 D.F., Mexico
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