Investigation of the dust formation and violent mass loss of evolved stars

研究演化恒星的尘埃形成和剧烈质量损失

• 批准号: 255614523
• 负责人: Dr. Iva Karovicova, Ph.D.
• 金额: --
• 依托单位: Institut für Theoretische Astrophysik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/255614523?language=en
• 关键词: Investigation; dust; formation; violent; mass

Evolved stars are the major source of stellar dust in our Galaxy, returning matter to the interstellarmedium and providing material for new star and planet formation. As such, their violent mass loss process is under intense investigation. The main motivation of the project is to study the strong mass loss occurring during the late stages of stellar evolution, which is still poorly understood. In particular, we want to focus on answering the following questions: How is the pulsation of stars on the Asymptotic Giant Branch (AGB) related to the dust condensation sequence and thus to the mass loss? What are the main differences between AGB stars and the more massive Red SuperGiant stars (RSGs)? How does the mass loss of oxygen-rich stars differ from that of carbon-rich stars? To answer these questions, the project focuses on studying evolved stars of different masses and chemical compositions observed with the highest available angular resolution, using the AMBER and MIDI instrument at the Very Large Telescope Interferometer (VLTI). The data will be exploited by using different theoretical codes: radiative transfer codes, an image reconstruction code, and a multidimensional hydrodynamical code. The scientific projects in this proposal are based on observations with AMBER and MIDI, the first generation interferometric instruments installed at the VLTI. However, part of the project is also dedicated to the next generation mid-infrared interferometric instrument MATISSE. MATISSE will open two new observing windows in the L and M bands. For the very first time, it will combine beams of 4 telescopes, allowing imaging in the mid-infrared band. This part of the project focuses on assisting with the preparation of user-friendly image reconstruction code, and on the implementation of the second generationfringe tracker. These tasks are of high importance since the first light from MATISSE is expected in 2016.

演化的恒星是银河系中恒星尘埃的主要来源，它们将物质返回到星际介质，并为新的星星和行星的形成提供物质。因此，他们的暴力质量损失过程正在紧张的调查中。该项目的主要动机是研究在恒星演化的后期阶段发生的强烈质量损失，这仍然是知之甚少。特别是，我们要集中回答以下问题：如何脉动的恒星的渐近巨星分支（AGB）有关的尘埃凝聚序列，从而质量损失？AGB星和更大质量的红超巨星（RSG）之间的主要区别是什么？富氧恒星的质量损失与富碳恒星的质量损失有何不同？为了回答这些问题，该项目的重点是利用甚大望远镜干涉仪（VLTI）上的琥珀色和琥珀色仪器，研究以最高可用角分辨率观测到的不同质量和化学成分的演化恒星。这些数据将利用不同的理论代码：辐射传输代码，图像重建代码，和多维流体动力学代码。该提案中的科学项目是基于安装在VLTI的第一代干涉仪AMBER和EAST的观测。然而，该项目的一部分也致力于下一代中红外干涉仪MATISSE。MATISSE将在L和M波段打开两个新的观测窗口。这是第一次，它将联合收割机结合4个望远镜的光束，允许在中红外波段成像。本项目的这一部分侧重于协助编写用户友好的图像重建代码，以及第二代条纹跟踪器的实现。这些任务非常重要，因为MATISSE的第一盏灯预计将于2016年发射。