2008/01/18 by Carigi, Leticia, Peimbert, Manuel
#Astrophysics (astro-ph) #FOS: Physical sciences
paper · doi:10.48550/arxiv.0801.2867
We present chemical evolution models for the Galactic disk. We also present a new determination of X, Y, and Z for M17 a Galactic metal-rich Hii region. We compare our models for the Galactic disk with the Galactic Hii regions abundances. The ΔY/ΔO ratio predicted from the galactic chemical evolution model is in very good agreement with the ΔY/ΔO value derived from M17 and the primordial helium abundance, Yp, taking into account the presence of temperature variations in this Hii region. From the M17 observations we obtain that ΔY/ΔZ = 1.97 ± 0.41, in excellent agreement with two ΔY/ΔZ determinations derived from K dwarf stars of the solar vicinity that amount to 2.1 ± 0.4 and 2.1 ± 0.9 respectively. We also compare our models with the solar abundances. The solar and Orion nebula O/H values are in good agreement with our chemical evolution model.