Stellar ISM dust sources: Carbide dust formation

恒星 ISM 尘埃源：碳化物尘埃的形成

• 批准号: 203380651
• 负责人: Dr. Beate Patzer
• 金额: --
• 依托单位: Zentrum für Astronomie und Astrophysik
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2011
• 资助国家: 德国
• 起止时间: 2010-12-31 至 2015-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/203380651?language=en
• 关键词: Stellar; ISM; dust; sources; Carbide

Dust particles play a central role in the astrophysics of the interstellar medium (ISM) - from chemistry and thermodynamics of the gas up to the dynamics of star formation. The lifecycle of the interstellar dust starts with the nucleation and growth of grains in steady winds or explosive ejecta of stars. Asymptotic giant branch (AGB) stars and type II supernovae (SNs) are particularly rich in detected dust compounds. Low and intermediate mass stars are thus among the most important dust sources in the interstellar medium of galaxies and the composition of dust ejected from these stars affect those in the ISM. Dust grains formed in such circumstellar envelopes are rather a mixture of several chemical elements as verified by many investigations of presolar stardust grains enclosed in meteorites, which are differentiated in carbon–rich and oxygen–rich solid materials.The main objective of this research project is the detailed theoretical study of the formation of carbide dust particles in circumstellar environments focussing mainly on the microphysical aspects of the nucleation and grain growth processes. In this context especially the role and importance of titanium carbide and silicon carbide in carbon dust formation is addressed. The unique characteristic of this research project is thereby that the complex multi–component dust growth is combined with the competitive treatment of different nucleation processes of the condensing materials. The knowledge of these processes is also important for understanding other dusty astrophysical environments.

尘埃粒子在星际介质天体物理学（ISM）中起着核心作用-从气体的化学和热力学到星星形成的动力学。星际尘埃的生命周期始于稳定风或恒星爆炸性喷出物中颗粒的成核和生长。渐近巨星分支（AGB）恒星和II型超新星（SN）中检测到的尘埃化合物特别丰富。因此，中低质量恒星是星系星际介质中最重要的尘埃源之一，从这些恒星喷出的尘埃的成分会影响ISM中的尘埃。在这种星周包层中形成的尘埃颗粒是几种化学元素的混合物，这一点已经被许多对陨石中包裹的前太阳星尘颗粒的研究所证实，不同的是富碳和富氧本研究项目的主要目标是详细的理论研究在拱星环境中碳化物尘埃颗粒的形成，主要集中在成核的微观物理方面。和晶粒生长过程。在这种情况下，特别是碳化钛和碳化硅在碳尘形成中的作用和重要性。该研究项目的独特之处在于将复杂的多组分尘埃生长与冷凝材料的不同成核过程的竞争性处理相结合。了解这些过程对于了解其他尘埃天体物理环境也很重要。