摘要
To obtain reliable Cu abundances with the APOGEE H-band spectra,it is important to investigate the non-local thermodynamic equilibrium(NLTE)effects on the formation of the H-band Cu I lines.In addition,the Cu atomic model needs to be tested.Based on both the high-resolution and high signal-tonoise ratio H-band spectra from the Apache Point Observatory Galactic Evolution Experiment(APOGEE)and optical data,we derived the LTE and NLTE copper abundances of 13 FGK sample stars with the spectral synthesis method.We find that the NLTE effects are negligible for the Cu I 16005.7?A line in the IR H-band.Consistent copper abundances within the uncertainties from these two sets of lines have been obtained,which indicates the reliability of our NLTE copper atomic model.We note that the[Cu/Fe]ratios increase with increasing metallicity when~–1.4 dex<[Fe/H]<~–0.5 dex,favoring a secondary(metallicity-dependent)copper production.
基金
the Key Research Program of the Chinese Academy of Sciences(Grant No.XDPB09-02)
the National Key Basic Research Program of China(Grant No.2014CB845700)
the National Natural Science Foundation of China(Grant Nos.11833006,11473033,11603037 and 11803049)
International partnership program’s Key foreign cooperation project,Bureau of International Cooperation,Chinese Academy of Sciences(Grant No.114A32KYSB20160049)
the Astronomical Big Data Joint Research Center
co-founded by the National Astronomical Observatories,Chinese Academy of Sciences and the Alibaba Cloud。
