<i>s-</i>process enrichment of ultrafaint dwarf galaxies

We study the production of barium (Ba) and strontium (Sr) in ultrafaint dwarf galaxies (UFDs). Both r- s- processes produce these elements, one can infer contribution r-process from characteristic abundance pattern, whereas s-process remains largely unknown. show that current yield asymptotic giant branch (AGB) stars is not sufficient to explain Ba Sr abundances observed UFDs. Production elements would need be efficient beginning star formation galaxies. The discrepancy nearly or more than 1 dex reconciled even if we consider super-AGB stars. a possible resolution by assuming rotating massive (RMSs) electron-capture supernovae (ECSNe) as additional contributors. find RMSs could origin UFDs ~ 10 per cent are at 300 km s^{-1}. As for ECSNe, argue their fraction less 2 core-collapse supernova. It narrows progenitor mass-range < 0.1 Msun -3 [Fe/H] -2. also explore another modifying stellar initial mass function (IMF) top-light IMF model reproduces level Ba-enrichment. Future observations determine tightly constrain europium nitrogen crucial identify