Spectroscopic abundance analysis of dwarfs in the young open cluster IC 4665
Authors:
          Zhixia Shen, Peking University, Beijing, P. R. China
          Burton Jones, UCO/Lick Observatory, University of California, Santa Cruz
          Douglas Lin, UCO/Lick Observatory, University of California, Santa Cruz
          Xiaowei Liu,  Peking University, Beijing, P. R. China
          Huawei Zhang, Peking University, Beijing, P. R. China
          Shulin Li, Peking University, Beijing, P. R. China

Abstract:
          We report the first detailed spectroscopic abundance analysis for the young open cluster IC 4665 for a sample of 18 F-K dwarfs. Stellar parameters and element abundances of Li, O, Mg, Si, Ca, Ti, Cr, Fe and Ni have been derived using the spectroscopic synthesis tool SME (Spectroscopy Made Easy). We find uniform iron abundance with a standard deviation of 0.04 dex, which is within our measurement uncertainties. No correlation is found between ion abundance and the mass of the stellar convective zone and between the Li abundance and the Fe abundance. In other words, no signature of accretion has been detected. Our results do not support the theory that the on the average higher metallicity of stars with planets than field stars is due to the pollution of metal-rich planetary material on the outer region of the central stars. It is more likely that planet formation is more efficient in environments of higher metallicity. On the other hand, it is possible that the bulk of the accreted material penetrates the thin convective zone into the deep stellar interior, and thus eludes detection by our current observations.