Spectroscopy of helium dwarf novae in AM CVn systems

AM CVn 系统中氦矮新星的光谱学

• 批准号: 27336705
• 负责人: Dr. Thorsten Nagel
• 金额: --
• 依托单位: Abteilungen Astronomie und Hochenergieastrophysik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2006
• 资助国家: 德国
• 起止时间: 2005-12-31 至 2006-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/27336705?language=en
• 关键词: Spectroscopy; helium; dwarf; novae; AM

Dwarf nova outbursts are assumed to be disc instabilities in CV systems leading to enhanced mass-accretion rates onto the primary white dwarf. We propose to perform spectroscopic observations of three helium dwarf novae in AM CVn binary systems. The donor star in AM CVn systems is a helium-rich (semi-) degenerate star, hence, the accretion disc is dominated by helium in contrast to other CVs. Therefore the outburst behaviour is rather different. The outburst cycle times of our targets are of the order of days. We want to study the spectral variability as a function of phase in order to characterize the physical states of accretion discs. The spectra will be analysed with non-LTE accretion disc models, which allow to determine, e.g., mass-accretion rate and chemical composition.

矮新星爆发被认为是CV系统中的圆盘不稳定性，导致主白色矮星上的质量吸积速率增强。我们建议在AMCVn双星系统中对三颗氦矮星新星进行光谱观测。AMCVn系统中的施主星星是一颗富氦（半）简并星星，因此吸积盘与其他CV相比主要由氦构成。因此，爆发行为相当不同。我们目标的爆发周期是几天。我们希望研究光谱变化作为相位的函数，以表征吸积盘的物理状态。光谱将用非LTE吸积盘模型进行分析，该模型允许确定，例如，质量增长率和化学成分。