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Small-scale inhomogeneities and their impact on observed mass-loss rates of radiation-driven winds

小尺度不均匀性及其对观测到的辐射驱动风质量损失率的影响

基本信息

批准号：
179960930
负责人：
Privatdozent Dr. Joachim Puls
金额：
--
依托单位：
Lehrstuhl für Theoretische und Numerische Astrophysik
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2011
资助国家：
德国
起止时间：
2010-12-31 至 2014-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/179960930?language=en
关键词：
Small scale inhomogeneities their impact

项目摘要

The mass-loss rate is a key parameter of hot, massive stars. Large reductions of O-star mass-loss rates currently in use have been suggested, by an order of magnitude or even more, as due to the effects of wind inhomogeneities (clumping). If confirmed, such low rates would have enormous implications for massive star evolution and feedback, and thereby also for the vast number of astrophysical applications relying on evolutionary predictions.However, both atmospheric modeling and spectral synthesis accounting for the effects of wind clumping are still in their infancies, and results stemming from current models have recently been challenged by different groups, including our own. We suggest to perform a multiwavelength study for a large sample of O-stars of different chemical compositions, by using new and significantly improved methods to model the structured wind and the line formation within the entire atmosphere. With this project we will investigate apparent conflicts between observations and theory, and provide a consistent and unique view of observed mass-loss rates in the present day Universe.Moreover, our new models will be used for investigating the role of wind clumping in the predictions of ionizing fluxes from hot, massive stars, for deriving accurate surface abundances, and for cutting edge extragalactic stellar astronomy even beyond the Local Group.

质量损失率是热的大质量恒星的一个关键参数。由于风的不均匀性（聚集）的影响，目前使用的O星质量损失率已经被建议大幅降低，降低了一个数量级甚至更多。如果得到证实，如此低的速率将对大质量星星的演化和反馈产生巨大影响，从而也对大量依赖演化预测的天体物理学应用产生巨大影响。然而，大气建模和解释风聚集效应的光谱合成仍处于起步阶段，当前模型的结果最近受到了不同团体的挑战，包括我们自己的团体。我们建议进行多波长的研究，为大样本的O-星的不同的化学成分，通过使用新的和显着改进的方法来模拟结构风和整个大气层内的线形成。通过这个项目，我们将调查观测和理论之间的明显冲突，并提供一个一致的和独特的观点，在当今宇宙中观测到的质量损失率。此外，我们的新模型将用于调查风聚集的作用，从热，大质量恒星的电离通量的预测，获得准确的表面丰度，并为尖端的河外恒星天文学，甚至超越本星系群。