Evolutions of Magnetized Supernova Remnants

磁化超新星遗迹的演化

• 批准号: 05640306
• 负责人: TOMISAKA Kohji
• 金额: $ 1.34万
• 依托单位: Niigata University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05640306/
• 关键词: Supernova Remnants; Interstellar Magnetic Fields; Magnetohydrodynamics

1. Evolutions of magnetized supernova remnants are studied with the ideal MHD simulation. Poloidal magnetic fields are taken into account and a two-dimensional axisymmetric MHD code is used.2. (1) "Monotonic Scheme" (a kind of TVD schemes) and "Constrained Transport Scheme, " which conserves strictly the divergence of magnetic fields, are adopted.(2) It is shown that the "Nested Grid" technique is applicable to the MHD simulations.3. The effect of the magnetic fields becomes crucial in a late phase of supernova remnants.(1) In the case of 5*10^<50> ergs of the explosion energy and 0.3cm^<-3> of the ambient density, the magnetic fields with B_0=5muG reduces the volume occupied with a hot gas to -20% of the volume expected for a nonmagnetic supernova remnant.(2) The magnetic tension plays a role after -1 Myr has passed since the supernova explosion occurs. The supernova remnant contracts due to the magnetic tension.4. This indicates that the volume fraction of hot interstellar matter seems much smaller than that suggested previously.

1. 用理想MHD模拟研究了磁化超新星残骸的演化过程。考虑了极向磁场，采用了二维轴对称MHD码。(1)采用严格守恒磁场散度的“单调格式”（TVD格式的一种）和“约束输运格式”。(2)结果表明，“嵌套网格”技术适用于MHD模拟。磁场的影响在超新星残骸的后期阶段变得至关重要。(1)在爆炸能量为5*10^<50> ergs，环境密度为0.3cm^<-3>的情况下，B_0=5muG的磁场使热气体占据的体积减少到非磁性超新星遗迹预期体积的-20%。(2)在超新星爆发后-1 Myr过后，磁张力起作用。超新星遗迹由于磁张力而收缩。这表明，热星际物质的体积分数似乎比之前提出的要小得多。

项目成果

Tomisaka,K.: "The Evolusion of Superbubble and Supernova Remnants in the Magnetized Interstellar Medium" Numerical Simulations in Astrophysics. (in press). (1994)

富坂，K.：“磁化星际介质中超级气泡和超新星遗迹的演化”天体物理学数值模拟。

Tomisaka, Kohji: "Collapse and Fragmentation of Magnetized Cylindrical Clouds.II.Simulation with the Nested Grid Scheme" The Astrophys. (J.in press). (1995)

富坂，Kohji：“磁化圆柱云的崩溃和碎片。II.使用嵌套网格方案进行模拟”天体物理学。

Tomisaka,K: "Extended Hot Gas Halo around Starburst Galaxies" Publ.Astron.Soc.Japan. 45. 513-528 (1993)

富坂，K：“星爆星系周围的扩展热气光环”Publ.Astron.Soc.Japan。

Tomisaka, Kohji: "The Evolution of Superbubble and Supernova Remnant in the magnetized Interstellar Medium" Numerical Simulations in Astrophysics. 184-191 (1994)

富坂幸司：“磁化星际介质中超级气泡和超新星遗迹的演化”天体物理学数值模拟。

Bregman,J.N.: "X-ray Emission from the Starburst Galaxy IC 342" Astrophys.J.Letters. 415. L79-L82 (1993)

Bregman,J.N.：“星爆星系 IC 342 的 X 射线发射”Astrophys.J.Letters。