Chemical abundances of three new Ba stars from the Keck/HIRES spectra  

作　　者：Shuai Liu Liang Wang Jian-Rong Shi Zhen-Yu Wu Hong-Liang Yan Qi Gao Chun-Qian Li 刘帅;王靓;施建荣;武振宇;闫宏亮;高琦;李春乾(CAS Key Laboratory of Optical Astronomy,National Astronomical Observatories,Chinese Academy of Sciences,Beijing 100101,China;School of Astronomy and Space Science,University of Chinese Academy of Sciences,Beijing 100049,China;National Astronomical Observatories/Nanjing Institute of Astronomical Optics&Technology,Chinese Academy of Sciences,Nanjing 210042,China;CAS Key Laboratory of Astronomical Optics&Technology,Nanjing Institute of Astronomical Optics&Technology,Chinese Academy of Sciences,Nanjing 210042,China)

机构地区：[1]CAS Key Laboratory of Optical Astronomy,National Astronomical Observatories,Chinese Academy of Sciences,Beijing 100101,China [2]School of Astronomy and Space Science,University of Chinese Academy of Sciences,Beijing 100049,China [3]National Astronomical Observatories/Nanjing Institute of Astronomical Optics&Technology,Chinese Academy of Sciences,Nanjing 210042,China [4]CAS Key Laboratory of Astronomical Optics&Technology,Nanjing Institute of Astronomical Optics&Technology,Chinese Academy of Sciences,Nanjing 210042,China

出　　处：《Research in Astronomy and Astrophysics》2021年第11期67-78,共12页天文和天体物理学研究（英文版）

基　　金：supported by the National Key R&D Program of China (No. 2019YFA0405502);the National Natural Science Foundation of China (Grant Nos. 12090040, 12090044, 11833006, 12022304, 11973052, 11973042, U2031144 and U1931102);supported by the Astronomical Big Data Joint Research Center, co-founded by the National Astronomical Observatories, Chinese Academy of Sciences (CAS);support from the Youth Innovation Promotion Association of the CAS (id. 2019060)

摘　　要：Based on high resolution,high signal-to-noise(S/N)ratio spectra from Keck/HIRES,we have determined abundances of 20 elements for 18 Ba candidates.The parameter space of these stars is in the range of 4880≤Teff≤6050 K,2.56≤log g≤4.53 dex and-0.27≤[Fe/H]≤0.09 dex.It is found that four of them can be identified as Ba stars with[s/Fe]>0.25 dex(s:Sr,Y,Zr,Ba,La,Ce and Nd),and three of them are newly discovered,which include two Ba giants(HD 16178 and HD 22233)and one Ba subgiant(HD 2946).Our results show that the abundances ofα,odd and iron-peak elements(O,Na,Mg,Al,Si,Ca,Sc,Ti,Mn,Ni and Cu)for our program stars are similar to those of the thin disk,while the distribution of[hs/ls](hs:Ba,La,Ce and Nd,ls:Sr,Y and Zr)ratios of our Ba stars is similar to those of the known Ba objects.None of the four Ba stars show clear enhancement in carbon including the known CH subgiant HD 4395.It is found that three of the Ba stars present clear evidence of hosting stellar or sub-stellar companions from the radial velocity data.

关 键 词：GALAXY Ba stars Chemical abundances Binary 

分 类 号：P148[天文地球—天体物理]