• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>The Astrophysical journal >ENHANCED COSMIC-RAY FLUX AND IONIZATION FOR STAR FORMATION IN MOLECULAR CLOUDS INTERACTING WITH SUPERNOVA REMNANTS
【24h】

ENHANCED COSMIC-RAY FLUX AND IONIZATION FOR STAR FORMATION IN MOLECULAR CLOUDS INTERACTING WITH SUPERNOVA REMNANTS

机译：与超新星残基相互作用的分子团中增强的宇宙射线通量和电离星形成

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Molecular clouds interacting with supernova remnants may be subject to greatly enhanced irradiation by cosmic rays produced at the shocked interface between the ejecta and the molecular gas. Over the past decade, broadband observations have provided important clues about these relativistic particles, indicating that they may dominate over the locally observed cosmic-ray population by a significant amount. In this Letter, we estimate the enhancement and find that the cosmic-ray energy density can be up to ～1000 times larger in the molecular cloud than in the field. This enhancement can last for a few million years and leads to a corresponding increase in the ionization fraction, which has important consequences for star formation. Ionization fractions in molecular cloud cores determine, in part, the rate of ambipolar diffusion, an important process in core formation and precollapse evolution. lonization fractions in newly formed circumstellar disks affect the magnetorotational instability mechanism, which in turn affects the rate of disk accretion. As estimated here, the increased ionization acts to increase the ambipolar diffusion time by a factor of ～30 and thereby suppresses star formation. In contrast, the increased ionization fraction reduces the sizes of dead zones in accretion disks (by up to an order of magnitude) and thus increases disk accretion rates (by a comparable factor).
机译：与超新星残余物相互作用的分子云可能会受到在喷射器与分子气体之间的冲击界面处产生的宇宙射线大大增强的照射。在过去的十年中，宽带观测提供了有关这些相对论粒子的重要线索，表明它们可能在当地观测到的宇宙射线种群中占主导地位。在这封信中，我们估计了这种增强，发现在分子云中宇宙射线的能量密度可以比在田间高约1000倍。这种增强作用可持续数百万年，并导致电离分数的相应增加，这对恒星的形成具有重要的影响。分子云核心中的电离部分决定了双极性扩散的速率，这是核心形成和前塌陷演化的重要过程。新形成的星际盘中的电离分数会影响磁旋转的不稳定性机制，进而影响盘的吸积率。如此处所估计的，增加的电离作用将双极性扩散时间增加了约30倍，从而抑制了恒星的形成。相反，增加的电离分数减小了吸积盘中死区的大小（增加了一个数量级），因此增加了吸积盘的吸积率（增加了可比因素）。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号