http://arxiv.org/abs/1906.07804
We present two chemical evolution models of our galaxy, both models are built to fit the O/H ratios derived from H II regions, using two different methods. One model is based on abundances obtained from the [O III] 4363/5007 temperatures (direct method, DM) and the other on abundances obtained from the recombination line ratios of [O II/H I] (temperature independent method, TIM). The differences between the O/H values obtained from these two methods are about 0.25 dex. We find that the model based on the TIM values produces an excellent fit to the observational stellar constraints (B-stars, Cepheids, and the Sun), while the model based on the DM fails to reproduce each of them. Moreover, the TIM model can explain the flattening of the O/H gradient observed in the inner disk due to the assumption of an inside-out star formation quenching, in the 3 – 6 kpc galactocentric range, starting ~ 9 Gyr ago.
L. Carigi, M. Peimbert and A. Peimbert
Thu, 20 Jun 19
21/51
Comments: 6 pages, 2 figures. Contributed talk given in the II workshop on Chemical Abundances in Gaseous Nebulae, held between 11-14 March 2019 in Sao Jose dos Campos, Sao Paulo, Brazil