Skip to content

S20B0071abst

S20B0071

Low mass dwarf galaxies enriched by r-process events are extremely valuable systems to study neutron star mergers in the early Universe, which is the only confirmed channel of r-process. In the hierarchically growing Universe, most of these dwarf galaxies have merged with larger systems and become part of its stellar halos, which is the case for the Milky Way. Thanks to Gaia, now we can find the debris of such dwarf galaxies from dynamical space in the inner stellar halo, where high-resolution spectroscopic observations are relatively easy. Here we propose to observe ∼ 24 members from five dynamically tagged groups (DTGs) that are confidently associated with known r-process-enhanced stars based on their orbital properties (Yuan et al. 2020). Given the high fractions of very metal-poor and r-rich members in the selected DTGs, their progenitors are very likely low-mass dwarf galaxies polluted by r-process events. There will be large chance of finding more r-rich members, which has been partially verified by our previous observation. The heavy element abundances of these DTG members would help uncover the birth environment of r-process events, which encodes the information on neutron star merger, initial mass function, and chemical enrichment in the early Universe.

This document was translated from LATEX by HEVEA.