# 2017 JINA-CEE Frontiers in Nuclear Astrophysics

Feb 7 – 9, 2017
US/Eastern timezone

## Constraining the energy and statistics of neutron star mergers by simulating R-process element production in ultra faint dwarf galaxies

Feb 9, 2017, 9:30 AM
15m

111 N Grand Ave, Lansing, MI 48933
Talk [Main Conference] Contributed talk

### Description

We perform cosmological zoom-in simulations with the goal of studying the energy and statistics of the neutron star mergers in order to explain the high observed abundances of R-process elements in local ultra faint dwarf (UFD) galaxies. We model our star formation in a stochastic fashion in order to resolve the stellar mass content the UFDs. We perform zoom simulations on two different halos at $z\sim6$ with mass $\sim10^8 M_{\odot}$ and model a single neutron star merger (NSM) in the start formation history of these systems. We explore the Injected energy range of $10^{50}-10^{51}$ erg and coalescence time scale of 1-20 Myr for the NSM event. We find the the distribution of the stars in [Eu/H] vs. [Fe/H] is mostly sensitive to the amount of R-process mass that is ejected into the ISM ($M_r$) per NSM event. We find that $M_r=10^{-3}M_{\odot}$ explains the observed abundance of R-process elements in the local UFDs and lower (higher) values of $M_r$ will heavily under(over) predict the [Eu/H] of the stars which is in not supported by the observations requiring only one such events to have taken place in the star formation history of the UFDs.