arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1105.2689astro-ph.HE
收藏

SN1006非热发射对局域星际磁场的约束

Constraints on local interstellar magnetic field from non-thermal emission of SN1006

F. Bocchino, S. Orlando, M. Miceli, O. Petruk

摘要:

双边超新星遗迹的同步辐射形态取决于粒子加速机制和观测几何。然而,与X射线和$γ$射线形态不同,射电辐射不依赖于母电子数的截止区,这使得它成为研究SNR中宇宙射线产生物理学的更简单和更直接的工具。我们的目的是从射电形态学中得到对局部磁场及其梯度方向的严格约束,以及对电子注入效率依赖的严格约束。我们进行了一组3D MHD模拟描述的膨胀的球形SNR通过磁化介质与非均匀ISMF。从模拟中,我们得出非热无线电地图,并将它们与SN1006残骸的观测结果进行比较。我们发现,SN 1006在1 GHz的无线电形态是最好的拟合模型与准平行注入效率,一个磁场的角度与视线的$38^\circ\pm 4^\circ$,和梯度的磁场强度向银道面,高于预期的变化的大尺度领域的银河系。我们的结论是SN 1006的射电肢是极冠,而不是位于天空平面上。研究SNRs的同步辐射对于获得残留物附近银河系磁场的信息以及更多关于实际注入效率的线索至关重要。

英文摘要:

The synchrotron radio morphology of bilateral supernova remnants depends on the mechanisms of particle acceleration and on the viewing geometry. However, unlike X-ray and $γ$-ray morphologies, the radio emission does not depend on the cut-off region of the parent electron population, making it a simpler and more straightforward tool to investigate the physics of cosmic ray production in SNRs. Our aim is to derive from the radio morphology tight constraints on the direction of the local magnetic field and its gradient, and on the obliquity dependence of the electron injection efficiency. We perform a set of 3D MHD simulations describing the expansion of a spherical SNR through a magnetized medium with a non-uniform ISMF. From the simulations, we derive non-thermal radio maps and compare them with observations of the SN1006 remnant. We find that the radio morphology of SN1006 at 1 GHz is best-fitted by a model with quasi-parallel injection efficiency, a magnetic field aspect angle of $38^\circ\pm 4^\circ$ with the line of sight, and a gradient of the field strength toward the galactic plane, higher then the expected variations of the large scale field of the Galaxy. We conclude that the radio limbs of SN1006 are polar caps, not lying in the plane of sky}. The study of the synchrotron radio emission of SNRs is of crucial importance to derive information on the galactic magnetic field in the vicinity of the remnants, and more hints on the actual injection efficiency scenario.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑