Gas Accretion in Protobinary and Evolution of Binary

原双星中的气体吸积和双星的演化

• 批准号: 17540212
• 负责人: HANAWA Tomoyuki
• 金额: $ 2.24万
• 依托单位: Chiba University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2005
• 资助国家: 日本
• 起止时间: 2005 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-17540212/
• 关键词: Theoretical Astronomy; Star Formation; Numerical Simulation; Binary; Accretion

Protostears and young stellar objects are characterized by their active gas accretion. Since most protostars are members of binary and multiple stars, it is important to assess the role of their companions on the gas accretion. However, the studies are very limited in part by technical difficulties. By employing nested grid technique we have succeeded in simulations of gas accretion in a binary system. They cover both the circumbinary disk and circumstellar disks simultaneously with high spatial resolution. We have found that pairs of spiral shock waves are excited in the circumbinary disk. A pair of the spiral shocks corotates with the binary while the other pairs rotate more slowly. When the corotating spiral shock waves get ahead of the others, the gas density rises near L2 point and the inflow onto the binary increases. Interaction between the other pairs of shock waves induce gas accretion within the circumbinary disk. It is also shown in simulations of high spatial resolution that the turbulence arises near L1 point. As related works we have performed simulations of binary formation. We also developed AMR code capable for still higher spatial resolution and numerical scheme for strong MHD shock waves for future studies.

原恒星和年轻恒星的特征是它们的活跃气体吸积。由于大多数原恒星都是双星和聚星的成员，因此评估它们的伴星在气体吸积中的作用是很重要的。然而，这些研究在一定程度上受到技术困难的限制。采用嵌套网格技术，成功地模拟了双星系统中的气体吸积。它们以高空间分辨率同时覆盖了环双星盘和拱星盘。我们发现在环双星盘中激发出成对的螺旋激波。一对螺旋激波与双星同步旋转，而其他对旋转得更慢。当共转螺旋激波超前时，气体密度在L2点附近上升，流入双星的流量增加。其他激波对之间的相互作用引起环双星盘内的气体吸积。在高空间分辨率的模拟中还显示，湍流在L1点附近产生。作为相关工作，我们对二元形成进行了模拟。我们还开发了具有更高空间分辨率的AMR程序和强磁流体激波的数值计算方案，为今后的研究提供了参考。

项目成果

Collapse and fragmentation of rotating magnetized clouds — II. Binary formation and fragmentation of first cores

• DOI: 10.1111/j.1365-2966.2005.09327.x
• 发表时间: 2005-06
• 期刊: Monthly Notices of the Royal Astronomical Society
• 影响因子: 4.8
• 作者: M. Machida;Tomoaki Matsumoto;T. Hanawa;K. Tomisaka

Collapse and Fragmentation of Rotating Magnetized Cloud I. Magnetic Flux-Spin Relation

旋转磁化云的塌缩和破碎 I. 磁通量-自旋关系

• 发表时间: 2005
• 期刊: Monthly Notices of the Royal Astronomical Society 362・2
• 作者: Chen Y.;Rao M.;Yoshihiro Tonegawa;Wunderli T.;M.N.Machida
• 通讯作者: M.N.Machida

Alignment of Outflows with Magnetic Fields in Cloud Cores

流出物与云核中的磁场对齐

• 发表时间: 2006
• 期刊: The Astrophysical Journal (Letters) 637
• 作者: T.Matsumoto;T.Nakazato;K.Tomisaka
• 通讯作者: K.Tomisaka

No High-Mass Protostars in the Silhouette Young Stellar Object M17-SO1

年轻恒星物体 M17-SO1 轮廓中没有大质量原恒星

• 发表时间: 2005
• 期刊: Nature V434-7036
• 作者: S.Sakabe;et al.;S.Sako et al.
• 通讯作者: S.Sako et al.

Second Core Formation and High-Speed Jets : Resistive Magnetohydodynamic Nested Grid Simulations

第二核心形成和高速射流：电阻磁流体动力学嵌套网格模拟

• 发表时间: 2006
• 期刊: The Astrophysical Journal 647・2
• 作者: Y.Lou;E.Yanagida;M.N.Machida
• 通讯作者: M.N.Machida