Convective Overshooting of Pulsating Subdwarf B Stars Using MESA

	Convective Overshooting of Pulsating Subdwarf B Stars Using MESA
	Li Z(李志)
	2021-12-03
会议日期	2021-12-03
会议地点	中国四川南充
关键词	subdwarfs convection evolution
其他题名	Convective Overshooting of Pulsating Subdwarf B Stars Using MESA
英文摘要	To explore the overshooting mixing beyond the convective core in core helium-burning stars,we use the k-ω model which is incorporated into the Modules of Experiments in Stellar Astrophysics（MESA） to investigate the overshooting mixing in evolution of subdwarf B（sdB）stars.The results of the evolutionary modelling of sdB stars are presented,and the development of the convective core can be divided into three stage.The mass of the convective core increases monotonically when the radiative temperature gradient monotonically,?rad,decreases outwardly,and the overshooting mixing presents exponential decay similar with Herwig（2000）.The splitting of the convective core occurred repeatedly when the minimum value of ?rad near the convective boundary is smaller than the adiabatic temperature gradient,?ad.The mass at the outer boundary of the convective shell Msc can exceed 0.2Msun after the central helium abundance drops to about Yc =0.45.It is close to the convective core masses derived by the asteroseismology for the younger models（0.22 ～ 0.28Msun）.In the final stage,the "core breathing pulses" happened two or three times.Helium injected into the convective core by the overshooting mixing,and increased the lifetime of sdB stars.The mass of the mixed region M mixed can raise to 0.303 Msun at last.The oxygen content in the central core of our g-mode sdB models are about 80 per cent by mass.For our sdB models with various overshooting schemes,the core breathing pulse is the key to the formation of the white dwarf with higher oxygen content.This may be an evidence to support the existence of the core breathing pulse.
产权排序	第1完成单位
会议录	中国天文学会2021年学术年会摘要集
资助机构	N/A
学科主题	天文学 ; 恒星与银河系 ; 恒星形成与演化 ; 恒星物理学
分类号	P152
语种	中文
内容类型	会议论文
源URL	[http://ir.ynao.ac.cn/handle/114a53/25128]
专题	云南天文台_恒星物理研究组
作者单位	云南天文台
推荐引用方式 GB/T 7714	Li Z. Convective Overshooting of Pulsating Subdwarf B Stars Using MESA[C]. 见:. 中国四川南充. 2021-12-03.