Heavy element contributions of rotating massive stars to interstellar medium
Heavy element contributions of rotating massive stars to interstellar medium
复制标题
旋转大质量恒星对星际介质的重元素贡献
DOI：
10.1088/1674-4527/21/5/129
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发表时间：
2021
影响因子：
1.8
通讯作者：
Liu He-Lei
中科院分区：
文献类型：
--
作者：
Wu Rui-Qing;Zhu Chun-Hua;Lu Guo-Liang;Wang Zhao-Jun;Liu He-Lei
利用恒星演化代码模块（MESA），我们计算了大质量恒星通过恒星风和核心坍缩超新星（CCSN）喷发到星际介质（ISM）的重元素产量。在我们的模型中，大质量恒星的初始质量（M ini）从13到80 M⊙，它们的初始旋转速度(V)为0,300和500 km s -1，它们的金属丰度为[Fe/H]= -3, -2， -1和0。来自恒星风的重元素产量主要受恒星自转的影响，恒星自转通过化学均匀演化改变了恒星表面的化学丰度，增加了质量损失率。我们估计恒星风可以产生大约10−2的重元素产量（对于低金属丰度模型）到几个M⊙的质量（对于低金属丰度和快速旋转模型）。CCSN抛射产生的重元素产率也取决于大量的残余质量，而残余质量主要由CO-core的质量决定。我们的模型计算出CCSN喷发产生的重元素的产量可以达到几个M⊙。与恒星风相比，CCSN抛射物对ISM中重元素的贡献更大。我们还比较了在这项工作中计算的56个Ni产量与观测估计。我们的模型只解释了由微弱的SNe或正常的SNe产生的56 Ni质量，其前身质量低于25 M⊙，而大大低估了由质量高于30 M⊙的恒星产生的56 Ni质量。
Employing the stellar evolution code Modules for Experiments in Stellar Astrophysics (MESA), we calculate yields of heavy elements from massive stars via stellar wind and core− collapse supernova (CCSN) ejecta to the interstellar medium (ISM). In our models, the initial masses (M ini) of massive stars are taken from 13 to 80 M⊙, their initial rotational velocities (V) are 0, 300 and 500 km s− 1, and their metallicities are [Fe/H]=–3,–2,–1 and 0. The yields of heavy elements coming from stellar winds are mainly affected by stellar rotation which changes the chemical abundances of stellar surfaces via chemically homogeneous evolution, and enhances mass-loss rate. We estimate that the stellar wind can produce heavy element yields of about 10− 2 (for low metallicity models) to a mass of several M⊙(for low metallicity and rapid rotation models). The yields of heavy elements produced by CCSN ejecta also depend on the large amount of remnant mass which is mainly determined by the mass of the CO-core. Our models calculate that the yields of heavy elements produced by CCSN ejecta can get up to several M⊙. Compared with stellar wind, CCSN ejecta has a greater contribution to the heavy elements in ISM. We also compare the 56 Ni yields calculated in this work with the observational estimate. Our models only explain the 56 Ni masses produced by faint SNe or normal SNe with progenitor mass lower than about 25 M⊙, and greatly underestimate the 56 Ni masses produced by stars with masses higher than about 30 M⊙.