Investigation Of Astrophysical Origin Of The Elements In The Kinematic Group 1、2、3 Of Galaxy

The observations show that the abundance ratio of the α-elements(O, Mg, Si, Ca, Ti) and some iron group elements(Sc, V, Cr, Fe, Co, Ni) and neutron-capture elements(Y, Zr, Ba, La, Ce, Pr, Nd, Sm, Eu) reveal different abundance trends for the stars in Group1, 2, 3 in Galaxy. In this work, For investigating the astrophysical reasons of the trends of α elements, iron group elements and neutron-capture elements, we use muti-components approach to investigate the astrophysical origins for the abundances,and analyse the astrophysical origins of the elements.The observations show that the contributions of the main r-process and primary process are flat as [Fe/H] increases for [Fe/H]<-0.4, but they decrease with [Fe/H] increases for [Fe/H]>-0.4; Meanwhile, the contributions of the main s-process, SNe Ia and secondary process increase with increasing [Fe/H]. Because O is thought as a “pure” primary element, the trends of [O/Fe] decrease monotonously as [Fe/H] increases for [Fe/H]>-0.4. The other α-elements Mg, Si, Ca, Ti are mainly from primary process, too. For an example of Mg, the trends of [Mg/Fe] are flat with [Fe/H] increases for [Fe/H]<-0.4,but the contributions of secondary process increase as [Fe/H] increases for [Fe/H]>-0.4, so the decreased trends of [Mg/Fe] are gentle. Compared with α-elements, the astrophysical origins of the iron group elements are more compalicated. For an example of Cr the trends of [Cr/Fe] are flat with [Fe/H] increases for [Fe/H]<-0.4, the reason is that the main astrophysical origins of the elements are primary procese; but for [Fe/H]>-0.4, the contributions of the SNe Ia are increasing with increasing [Fe/H] and compensate the decreased trends of primary procese, which leads to the flat trends of [Cr/Fe]. For neutron-capture elements, Y is taken as example, the abundance ratios of Y are flat with [Fe/H] increases for [Fe/H]<-0.4, the reason is that Y are mainly from weak r-process which is with primary trait; for [Fe/H]>-0.4, the contributions of weak r-process decrease with [Fe/H] increases, but the contributions of main s-process compensate the decreased trends of weak r-process which make the trends of [Y/Fe] flat. For an example of Ba, the trends of [Ba/Fe] are flat with [Fe/H] increases for [Fe/H]<-0.4, the reason is that the main astrophysical origins of the elements are main r-procese which is with primary trait; for [Fe/H]>-0.4, the trends of [Ba/Fe] increase with [Fe/H] increases, because main s-process increase as [Fe/H] increases. Eu is taken as example, for [Fe/H]>-0.4, the trends of and [Eu/Fe] are flat with [Fe/H] increases, the reason is that Eu abundances are mainly from main r-process; for [Fe/H]>-0.4, the trends of and [Eu/Fe] decrease with [Fe/H] increases, because the contributions of main r-process decrease with [Fe/H] increases.In this work, we regard O as a standard element to take the place of Fe, and we give out the trends of [X/O] and their astrophysical reasons. The contributions of the main r-process and primary process are flat as [Fe/H] increases which are with primary trait, but the contributions of the main s-process, SNe Ia and secondary process increase with increasing [Fe/H]. α-elements Mg is taken as example, for [Fe/H]<-0.4, the trends of [Mg/O] are flat with [Fe/H] increases; but the contributions of secondary process increase as [Fe/H] increases for [Fe/H]>-0.4, so the trends of [Mg/O] increase. For iron group elements, Cr is taken as example, the trends of [Cr/O] are flat with [Fe/H] increases for [Fe/H]<-0.4, the reason is that the main astrophysical origins of the elements are primary procese; for [Fe/H]>-0.4, the trends of [Cr/O] are flat because of the compensations of SNe Ia. For neutron-capture elements, for an example of Y, the trends of [Y/O] are flat with [Fe/H] increases for [Fe/H]<-0.4, the reason is that Y are mainly from weak r-process which is with primary trait; for [Fe/H]>-0.4, the contributions of main s-process to Y increase with [Fe/H] increases and beyond the contributions of weak r-process. Ba is taken as example, for [Fe/H]<-0.4, the trends of [Ba/O] are flat with [Fe/H] increases, the reason is that the main astrophysical origins of the elements are main r-procese and main s-procese, and they are not almost variational with [Fe/H] increases; for [Fe/H]>-0.4, the trends of [Ba/O] increase as [Fe/H] increases, because the contributions of main s-process to Ba increase with [Fe/H] increases and beyond the contributions of main r-process. For an example of Eu, the trends of [Eu/O] are flat as [Fe/H] increases, the reason is that Eu is mainly from main r-process which is with primary trait...