论文标题
金属丰富的AGB星星的气体和灰尘
Gas and dust from metal-rich AGB stars
论文作者
论文摘要
环境：通过渐近巨型分支（AGB）相变的恒星为其宿主系统提供了显着的反馈，它们的形式富含核燃烧产物和风中形成的尘埃，它们会弹出到星际介质中。因此，AGB恒星是银河系和其他星系化学演化的重要成分。目的：我们研究具有超极性金属性的AGB模型，以完成我们的大数据库，到目前为止，从金属贫困到太阳能化学成分。我们为范围1-8 MSUN的质量提供化学产率，金属Z = 0.03和Z = 0.04。我们还研究了该金属性域中的灰尘生产。方法：我们从主序列到整个AGB阶段计算了进化序列。我们遵循表面化学成分的变化，以计算各种物种的化学产率，并在风中形成灰尘，以确定灰尘产量和在AGB阶段每颗星产生的总灰尘质量。结果：恒星的物理和化学演变对初始质量敏感：M> 3msun恒星经历热底部燃烧，而下部质量对应物的表面化学仅通过第三挖掘而改变。碳星阶段的金属度Z = 0.03的2.5-3.5msun恒星，而所有Z = 0.04星（2.5 msun除外）在整个AGB相位均保持O-RICH。金属丰富的AGB产生的大多数灰尘都是硅酸盐颗粒的形式。随着恒星的质量，产生的灰尘总质量增加，到达 〜0.012 MSUN，用于8msun恒星。
Context: Stars evolving through the asymptotic giant branch (AGB) phase provide significant feedback to their host system, in form of both gas enriched in nuclear-burning products and dust formed in their winds, which they eject into the interstellar medium. Therefore AGB stars are an essential ingredient for the chemical evolution of the Milky Way and other galaxies. Aims: We study AGB models with super-solar metallicity, to complete our large database, so far extending from metal-poor to solar chemical compositions. We provide chemical yields for masses in the range 1-8 Msun and metallicities Z=0.03 and Z=0.04. We also study dust production in this metallicity domain. Methods: We calculated the evolutionary sequences from the pre main sequence through the whole AGB phase. We follow the variation of the surface chemical composition to calculate the chemical yields of the various species and model dust formation in the winds to determine the dust production rate and the total dust mass produced by each star during the AGB phase. Results: The physical and chemical evolution of the star is sensitive to the initial mass: M> 3Msun stars experience hot bottom burning, whereas the surface chemistry of the lower mass counterparts is altered only by third dredge-up. The carbon-star phase is reached by 2.5-3.5Msun stars of metallicity Z=0.03, whereas all the Z=0.04 stars (except the 2.5 Msun) remain O-rich for the whole AGB phase. Most of the dust produced by metal-rich AGBs is in the form of silicates particles. The total mass of dust produced increases with the mass of the star, reaching ~ 0.012 Msun for 8Msun stars.
