Asteroseismology based on high time-resolution and high dispersion spectroscopy

基于高时间分辨率和高色散光谱的星震学

• 批准号: 23540260
• 负责人: SHIBAHASHI Hiromoto
• 金额: $ 3.16万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2011
• 资助国家: 日本
• 起止时间: 2011 至 2013
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-23540260/
• 关键词: 星震学; 脈動星; 特異星; B型輝線星; 分光観測; データ解析; スペクトル線; 恒星大気; 衝撃波; 恒星物理学; 恒星脈動; 恒星スペクトル; 国際情報交流（英国）

The vertical wavelengths of the oscillations found in roAp stars are so short that the amplitude and phase of the variation of each spectroscopic line are highly dependent on the level of the line profile. We carried out a numerical simulation of line-profile variation by taking account of the finite thickness of the line-forming layer. We demonstrated how effective this treatment is.Barycentric corrections made to the timing of Kepler observations break the regular time-sampling of the data. A consequence is that Nyquist aliases are split into multiplets that can be identified by their shape. We provided an analytical derivation of the phenomenon, alongside demonstrations with simulated and real Kepler data.Observations indicate that a circumstellar disk is formed around a Be star while the stellar rotation is below the break-up velocity. I proposed a working hypothesis to explain this mystery by taking account of the effect of leaky waves upon angular momentum transfer.

在roAp星中发现的振荡的垂直波长是如此之短，以至于每条光谱线的变化的振幅和相位高度依赖于线轮廓的水平。我们进行了数值模拟的线轮廓的变化，考虑到有限的线形成层的厚度。我们证明了这种处理是多么有效，对开普勒观测时间的重心校正打破了数据的常规时间采样。结果是奈奎斯特别名被分成可以通过其形状识别的多重谱。我们提供了一个分析推导的现象，以及演示与模拟和真实的开普勒data.Observations表明，一个拱星盘周围形成的Be星星，而恒星的旋转是低于分裂速度。我提出了一个工作假设来解释这个谜，考虑到漏波的影响角动量转移。

项目成果

Radial velocities from photometry

光度测定的径向速度

• 发表时间: 2012
• 作者: Shibahashi;H.
• 通讯作者: H.

Traditional approximation for low-frequency modes in rotating stars and a working hypothesis about episodic mass-loss in Be stars

旋转恒星低频模式的传统近似和 Be 星中偶发质量损失的工作假设

• 发表时间: 2011
• 作者: Shibahashi;H
• 通讯作者: H

roAp星におけるスペクトル線プロファイル変動

roAp 星的谱线剖面变化

• 发表时间: 2011
• 作者: 内藤 純;柴橋 博資
• 通讯作者: 柴橋 博資

FM stars: A Fourier view of pulsating binary stars, a new technique for measuring radial velocities photometrically

• DOI: 10.1111/j.1365-2966.2012.20654.x
• 发表时间: 2012-02
• 期刊: arXiv: Solar and Stellar Astrophysics
• 作者: H. Shibahashi;D. Kurtz

Numerical Simulations of Line-Profile Variation beyond a Single-Surface Approximation for Oscillations in roAp Stars

roAp 星振荡超出单表面近似的线轮廓变化的数值模拟

• DOI: 10.1093/pasj/64.1.9
• 发表时间: 2012
• 期刊: Publ. Astron. Soc. Japan
• 作者: Nomura;T.;Naito;J.;and Shibahashi;H
• 通讯作者: H