We investigate the production sites and the enrichment history of r -process elements in the Galaxy , as traced by the [ Eu/Fe ] ratio , using the high resolution , cosmological zoom-in simulation ‘ Eris ’ .
At z = 0 , Eris represents a close analog to the Milky Way , making it the ideal laboratory to understand the chemical evolution of our Galaxy .
Eris formally traces the production of oxygen and iron due to Type-Ia and Type-II supernovae .
We include in post-processing the production of r -process elements from compact binary mergers .
Unlike previous studies , we find that the nucleosynthetic products from compact binary mergers can be incorporated into stars of very low metallicity and at early times , even with a minimum delay time of 100 Myr .
This conclusion is relatively insensitive to modest variations in the merger rate , minimum delay time , and the delay time distribution .
By implementing a first-order prescription for metal-mixing , we can further improve the agreement between our model and the data for the chemical evolution of both [ \alpha /Fe ] and [ Eu/Fe ] .
We argue that compact binary mergers could be the dominant source of r -process nucleosynthesis in the Galaxy .