(Proposal ID) S14B-150 (PI) Aoki Wako (Proposal Title) Chemical signatures of first-generation super-massive stars (Abstract) The mass distribution of the first generations of stars is a key requirement for understanding the cosmological structure formation and chemical enrichment in the early Universe. Our previous search for very/extremely metal-poor stars discovered an object with [Fe/H]=-2.5 that possesses elemental-abundance ratios that differ significantly from any previously known metal-deficient star, including very low abundance ratios of C, Mg and heavy neutron-capture elements. The abundance ratios of this star, SDSS J0018-0939, are best explained by the yields of the supernova explosion of a super- massive stars (> 100M_sun). This explanation still has some difficulty, in particular, discrepancies between the observed abundance ratios and model predictions for Si and elements with odd atomic number (e.g., Sc). The data quality of our previous study is, however, not sufficient to well constrain the abudances of these elements. We propose to obtain a high resolution, high S/N spectrum of this object using HDS to examine the interpretation that this object provides the first clear evidence for the existence of super-massive stars in first-generation stars in the early Universe.