Star Formation Timescales of the Halo Populations from Asteroseismology and Chemical Abundances**Based on data collected with the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan.
文献类型：期刊论文
| 作者 | Matsuno,Tadafumi6,9,11; Aoki,Wako6,9; Casagrande,Luca8; Ishigaki,Miho N.5; Shi,Jianrong10 ; Takata,Masao2; Xiang,Maosheng3; Yong,David8; Li,Haining10; Suda,Takuma1,4,7
|
| 刊名 | The Astrophysical Journal
 |
| 出版日期 | 2021-05-01 |
| 卷号 | 912期号:1 |
| ISSN号 | 0004-637X |
| 关键词 | Halo stars Asteroseismology Chemical abundances Stellar kinematics High resolution spectroscopy Stellar ages |
| DOI | 10.3847/1538-4357/abeab2 |
| 英文摘要 | Abstract We combine asteroseismology, optical high-resolution spectroscopy, and kinematic analysis for 26 halo red giant branch stars in the Kepler field in the range of ?2.5 < [Fe/H] < ?0.6. After applying theoretically motivated corrections to the seismic scaling relations, we obtain an average mass of 0.97 ± 0.03 M⊙ for our sample of halo stars. Although this maps into an age of ～7 Gyr, significantly younger than independent age estimates of the Milky Way stellar halo, we considered this apparently young age to be due to the overestimation of stellar mass in the scaling relations. There is no significant mass dispersion among lower red giant branch stars (log g > 2), which constrains the relative age dispersion to <18%, corresponding to <2 Gyr. The precise chemical abundances allow us to separate the stars with [Fe/H] > ?1.7 into two [Mg/Fe] groups. While the [α/Fe] and [Eu/Mg] ratios are different between the two subsamples, [s/Eu], where s stands for Ba, La, Ce, and Nd, does not show a significant difference. These abundance ratios suggest that the chemical evolution of the low-Mg population is contributed by Type Ia supernovae, but not by low- to intermediate-mass asymptotic giant branch stars, providing a constraint on its star formation timescale as 100 Myr < τ < 300 Myr. We also do not detect any significant mass difference between the two [Mg/Fe] groups, thus suggesting that their formation epochs are not separated by more than 1.5 Gyr. |
| 语种 | 英语 |
| 出版者 | The American Astronomical Society |
| WOS记录号 | IOP:0004-637X-912-1-ABEAB2 |
| 源URL | [http://ir.bao.ac.cn/handle/114a11/58216]  |
| 专题 | 中国科学院国家天文台 |
| 通讯作者 | Matsuno,Tadafumi |
| 作者单位 | 1.Department of Liberal Arts, Tokyo University of Technology, Nishi Kamata 5-23-22, Ota-ku, Tokyo 144-8535, Japan 2.Department of Astronomy, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan 3.Max-Planck Institute for Astronomy, K?nigstuhl 17, D-69117 Heidelberg, Germany 4.The Open University of Japan, Wakaba 2-11, Mihama-ku, Chiba 261-8586, Japan 5.Astronomical Institute, Tohoku University, Sendai 980-8578, Japan 6.National Astronomical Observatory of Japan (NAOJ), 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan 7.Research Center for the Early Universe, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan 8.Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611, Australia 9.Department of Astronomical Science, School of Physical Sciences, SOKENDAI, The Graduate University for Advanced Studies, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan 10.Key Lab of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100101, People’s Republic of China |
| 推荐引用方式 GB/T 7714 | Matsuno,Tadafumi,Aoki,Wako,Casagrande,Luca,et al. Star Formation Timescales of the Halo Populations from Asteroseismology and Chemical Abundances**Based on data collected with the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan.[J]. The Astrophysical Journal,2021,912(1). |
| APA | Matsuno,Tadafumi.,Aoki,Wako.,Casagrande,Luca.,Ishigaki,Miho N..,Shi,Jianrong.,...&Zhao,Jingkun.(2021).Star Formation Timescales of the Halo Populations from Asteroseismology and Chemical Abundances**Based on data collected with the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan..The Astrophysical Journal,912(1). |
| MLA | Matsuno,Tadafumi,et al."Star Formation Timescales of the Halo Populations from Asteroseismology and Chemical Abundances**Based on data collected with the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan.".The Astrophysical Journal 912.1(2021). |
入库方式： OAI收割
来源：国家天文台
浏览0
下载0
收藏0
其他版本
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。