S22B0094
S22B0094
The very metal-poor dwarf galaxy streams are the direct fossils from small and chemically pristine dwarf galaxies in the very early universe. Stellar streams are significantly closer than the closest dwarf galaxies, and can provide brighter targets for detailed elemental abundance analysis. The Cetus stream has been confirmed to be one of such streams, with mean [Fe/H] = −2.17±0.20 and estimated stellar mass >∼105.6M⊙, similar to Sextans dSph. We propose to get precise measurements of Fe and α-elements (Mg, Ca) for 17 Cetus giant stars (G = 14 - 15.5) in the metallicity range of −2.9 – −1.7. This proposal will reveal the scatter and slope of [α/Fe] as a function of [Fe/H], and can further constrain the stellar mass of the Cetus progenitor by comparing with the abundance studies in Sextans and Sculptor dSphs. We will also measure the heavy element abundances (Ba, Sr, and Eu) to quantify the contributions from s- and r- processes for the very metal-poor stars in a low-mass dwarf galaxy for the first time. Two thirds of the bright Cetus members are distributed in the northern sky, therefore Subaru/HDS is the ideal instrument to efficiently acquire these spectra with the required resolution and signal to noise ratio.
This document was translated from LATEX by HEVEA.