Convective Overshooting in Extreme Horizontal-branch Stars Using MESA with the k-omega Model* | |
Li Z(李志)1,2,3![]() ![]() | |
Source Publication | ASTROPHYSICAL JOURNAL
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2021-12 | |
Volume | 923Issue:2 |
DOI | 10.3847/1538-4357/ac2d8e |
Contribution Rank | 第1完成单位 |
Indexed By | SCI |
Abstract | To explore overshoot mixing beyond the convective core in core helium-burning stars, we use the k-omega model, which is incorporated into the Modules of Experiments in Stellar Astrophysics to investigate overshoot mixing in the evolution of subdwarf B (sdB) stars. Our results show that the development of the convective core can be divided into three stages. The mass of the convective core increases monotonically when the radiative temperature gradient, backward difference (rad), monotonically decreases outwardly, and overshoot mixing presents an exponential decay similar to Herwig. The splitting of the convective core occurs repeatedly when the minimum value of backward difference (rad) near the convective boundary is smaller than the adiabatic temperature gradient, backward difference (ad). The mass at the outer boundary of the convective shell M (sc) can exceed 0.2 M (circle dot) after the central helium abundance drops to about Y (c) approximate to 0.45. It is close to the convective core masses derived by asteroseismology for younger models (0.22 to similar to 0.28 M (circle dot)). In the final stage, core breathing pulses occurred two or three times. Helium was injected into the convective core by overshoot mixing and increased the lifetime of sdB stars. The mass of the mixed region M (mixed) can rise to 0.303 M (circle dot) by the end. The oxygen content in the central core of our g-mode sdB models is about 80% by mass. The high amounts of oxygen deduced from asteroseismology may be evidence supporting the existence of core breathing pulses. |
Funding Project | NSFC of ChinaNational Natural Science Foundation of China (NSFC)[11973079] ; NSFC of ChinaNational Natural Science Foundation of China (NSFC)[11521303] |
Funding Organization | NSFC of ChinaNational Natural Science Foundation of China (NSFC)[11973079, 11521303] |
Language | 英语 |
Subject Area | 天文学 ; 恒星与银河系 ; 恒星物理学 |
MOST Discipline Catalogue | 理学 ; 理学::天文学 |
Subtype | Article |
Publisher | IOP Publishing Ltd |
Publication Place | TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND |
ISSN | 0004-637X |
URL | 查看原文 |
WOS ID | WOS:000731758300001 |
WOS Research Area | Astronomy & Astrophysics |
WOS Subject | Astronomy & Astrophysics |
WOS Keyword | SUBDWARF-B-STARS ; HELIUM-BURNING MODELS ; BREATHING PULSES ; CORE PARAMETERS ; SDB STARS ; EVOLUTION ; ORIGIN ; BALLOON-090100001 ; PULSATORS |
Citation statistics | |
Document Type | 期刊论文 |
Version | 出版稿 |
Identifier | http://ir.ynao.ac.cn/handle/114a53/24752 |
Collection | 恒星物理研究组 中国科学院天体结构与演化重点实验室 |
Affiliation | 1.Yunnan Observatories, Chinese Academy of Sciences, P.O. Box 110 Kunming, 650216, People's Republic Of China; 2.University of Chinese Academy of Sciences, No.19(A) Yuquan Road, Shijingshan District, Beijing, 100049, People's Republic Of China; 3.Key Laboratory for Structure and Evolution of Celestial Objects, Chinese Academy of Sciences, P.O. Box 110 Kunming, 650216, People's Republic Of China; 4.Center for Astronomical Mega-Science, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing, 100012, People's Republic Of China |
First Author Affilication | Yunnan Observatories, Chinese Academy of Sciences |
Recommended Citation GB/T 7714 | Li Z,Li Y. Convective Overshooting in Extreme Horizontal-branch Stars Using MESA with the k-omega Model*[J]. ASTROPHYSICAL JOURNAL,2021,923(2). |
APA | Li Z,&Li Y.(2021).Convective Overshooting in Extreme Horizontal-branch Stars Using MESA with the k-omega Model*.ASTROPHYSICAL JOURNAL,923(2). |
MLA | Li Z,et al."Convective Overshooting in Extreme Horizontal-branch Stars Using MESA with the k-omega Model*".ASTROPHYSICAL JOURNAL 923.2(2021). |
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