Nucleosynthesis signatures of neutrino-driven winds from proto-neutron stars: a perspective from chemical evolution models

We test the hypothesis that observed first-peak (Sr, Y, Zr) and second-peak (Ba) s-process elemental abundances in low-metallicity Milky Way stars, of elements Mo Ru, can be explained by a pervasive r-process contribution originating neutrino-driven winds from highly-magnetic rapidly rotating proto-neutron stars (proto-NSs). construct chemical evolution models incorporate recent calculations proto-NS yields addition to contributions AGB Type Ia supernovae, two alternative sets for massive star core-collapse supernovae. For non-rotating either set, without underpredict peak $0.3$-$1\,\text{dex}$ at low metallicity, they severely Ru all metallicities. Models incorporating wind proto-NSs with spin periods $P \sim 2$-$5\,\text{ms}$ fit trends these well. Alternatively, omitting but adopting $v_{\rm rot}$ between $150$ $300\,\text{km}\,\text{s}^{-1}$, explain abundance levels reasonably well $\text{[Fe/H]}<-2$. These overpredict [Sr/Fe] [Mo/Fe] higher metallicities, tuned dependence on stellar metallicity might achieve an acceptable [Fe/H]. If many are born strong magnetic fields short periods, then their provide natural source Sr, Zr, Mo, Ba populations. Conversely, spherical unmagnetized overproduce Zr large factor.