Chemical evolution models: the role of type Ia supernovae in the α-elements over iron relative abundances and their variations in time and space

ABSTRACT The role of type Ia supernovae (SN Ia), mainly the delay time distributions (DTDs) determined by the binary systems, and the yields of elements created by different explosion mechanisms, are studied by using the MulChem chemical evolution model applied to our Galaxy. We explored 15 DTDs and 12 tables of elemental yields produced by different SN Ia explosion mechanisms, doing a total of 180 models. Chemical abundances for $\alpha$-elements (O, Mg, Si, and Ca) and Fe derived from these models are compared with recent solar region observational data of $\alpha$-elements over Fe relative abundances, [X/Fe], as a function of [Fe/H] and age. A multidimensional maximum-likelihood analysis shows that 52 models are able to fit all these data sets simultaneously, considering the 1$\sigma$ confidence level. The combination of STROLG1 DTD from Strolger et al. (2020) and LN20181 SN Ia yields from Leung & Nomoto (2018) provides the best fit. The exponential model with very prompt events is a possible DTD, but a combination of several channels is more probable. The SN Ia yields that include MCh or Near MCh correspond to 39 (75 per cent) of the 52 best models. Regarding the DTD, 31 (60 per cent) of the 52 most probable models correspond to the SD scenario, while the remaining 21 (40 per cent) are based on the DD scenario. Our results also show that the relatively large dispersion of the observational data may be explained by the stellar migration from other radial regions, and/or perhaps a combination of DTDs and explosion channels.