Speaker
Dr
Mohammadtaher Safarzadeh
(Arizona State University)
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.
Primary author
Dr
Mohammadtaher Safarzadeh
(Arizona State University)
Co-author
Prof.
Evan Scannapieco
(Arizona State University)