Ba-enhanced Dwarf and Subgiant Stars in the LAMOST Galactic Surveys

Meng Zhang; Maosheng Xiang; Hua-Wei Zhang; Yuan-Sen Ting; Ya-Qian Wu; Xiao-Wei Liu

doi:10.3847/1538-4357/acbcc4

The Astrophysical Journal (Jan 2023)

Ba-enhanced Dwarf and Subgiant Stars in the LAMOST Galactic Surveys

Meng Zhang,
Maosheng Xiang,
Hua-Wei Zhang,
Yuan-Sen Ting,
Ya-Qian Wu,
Xiao-Wei Liu

Affiliations

Meng Zhang: ORCiD; Department of Astronomy, School of Physics, Peking University , Beijing 100871, People’s Republic of China ; [email protected]; Kavli Institute of Astronomy and Astrophysics, Peking University , Beijing 100871, People’s Republic of China; South-Western Institute For Astronomy Research, Yunnan University , Kunming 650500, People’s Republic of China ; [email protected]; National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, People’s Republic of China
Maosheng Xiang: ORCiD; National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, People’s Republic of China; Institute for Frontiers in Astronomy and Astrophysics, Beijing Normal University , Beijing 102206, People’s Republic of China; Max-Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg, Germany
Hua-Wei Zhang: ORCiD; Department of Astronomy, School of Physics, Peking University , Beijing 100871, People’s Republic of China ; [email protected]; Kavli Institute of Astronomy and Astrophysics, Peking University , Beijing 100871, People’s Republic of China
Yuan-Sen Ting: ORCiD; Research School of Astronomy & Astrophysics, Australian National University , Cotter Road, Weston, ACT 2611, Australia; School of Computing, Australian National University , Acton, ACT 2601, Australia
Ya-Qian Wu: National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, People’s Republic of China
Xiao-Wei Liu: ORCiD; South-Western Institute For Astronomy Research, Yunnan University , Kunming 650500, People’s Republic of China ; [email protected]

DOI: https://doi.org/10.3847/1538-4357/acbcc4
Journal volume & issue: Vol. 946, no. 2
p. 110

Abstract

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Ba-enhanced stars are interesting probes of stellar astrophysics and Galactic formation history. In this work, we investigate the chemistry and kinematics of a large sample of Ba-enhanced ([Ba/Fe]>1.0) dwarf and subgiant stars with 5000 6000 K. They are likely the consequences of stellar internal element transport processes, but they show very different element patterns to hotter Am/Fm stars. Our results reveal a substantially lack of high-[ α /Fe], Ba-enhanced stars in the [Fe/H]–[ α /Fe] plane, which we dub as a “high-[α/Fe] desert”. We suggest it is due to a lower efficiency for producing Ba-enhanced stars by low-mass asymptotic giant branch progenitors in binary systems. Our results call for detailed modeling of these Ba-enhanced stellar peculiarities, in the context of both stellar internal element transport and external mass accretion.

Published in The Astrophysical Journal

ISSN: 1538-4357 (Online)
Publisher: IOP Publishing
Country of publisher: United Kingdom
LCC subjects: Science: Astronomy: Astrophysics
Website: https://iopscience.iop.org/journal/0004-637X

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