Oral Presentation

s-process enrichment of ultrafaint dwarf galaxies

Author(s): Yuta Tarumi (UTokyo), Takuma Suda (Tokyo University of Technology), Robert J.J. Grand (Max-Planck Institute for Astrophysics), Freeke van de Voort (Cardiff University), Shigeki Inoue (University of Tsukuba), Naoki Yoshida (UTokyo)

Presenter: Yuta Tarumi (The University of Tokyo)

We study the production of barium (Ba) and strontium (Sr) in ultrafaint dwarf galaxies (UFDs). With cosmological simulation we show that asymptotic giant branch (AGB) stars are not sufficient to explain the Ba and Sr abundances observed in UFDs. The discrepancy of nearly or more than 1 dex is not reconciled even if we consider s-process element production in super-AGB stars.
I will present possible resolution of the scarcity of s-process elements by rotating massive stars (RMSs) and electron-capture supernovae (ECSNe). Also I discuss the possibility of IMF modification as the solution to the problem.