Geometry of the non-thermal emission in SN 1006 - Azimuthal variations of cosmic-ray acceleration
Geometry of the non-thermal emission in SN 1006 - Azimuthal variations of cosmic-ray acceleration
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DOI：
10.1051/0004-6361:20047104
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发表时间：
2004-10
影响因子：
6.5
通讯作者：
R. Rothenflug;J. Ballet;G. Dubner;E. Giacani;A. Decourchelle;P. Ferrando
中科院分区：
文献类型：
--
作者：
R. Rothenflug;J. Ballet;G. Dubner;E. Giacani;A. Decourchelle;P. Ferrando
SN 1006是壳超新星残余物的原型，其x射线光谱以非热同步辐射为主。非热辐射是由于宇宙射线电子在爆炸波后面加速产生的。x射线同步加速器发射是由于最高能量的电子，因此是一个最大能量的电子可能达到激波后的示踪。我们把所有的xmm -牛顿观测数据放在一起，构建了一张SN 1006的完整地图。内部的亮度低于2kev，这表明明亮的非热翼是极帽而不是赤道。这意味着周围的磁场沿着银道面从西南到东北。我们使用组合的VLA/Parkes射电图来固定低能量的光谱，并通过截止幂律电子分布和热成分的同步加速器发射来模拟光谱。我们给出了截止频率的径向和方位角剖面。截止频率随半径靠近中心和位置角度远离最大发射而急剧下降。加速粒子所能达到的最大能量，以及它们的数量，在明亮的边缘一定比其他地方要高。这暗示了垂直冲击下加速度的有趣约束。总的来说，XMM-Newton的数据与磁场被放大的模型是一致的，在这个模型中，加速度是有效的。
SN 1006 is the prototype of shell supernova remnants, in which non-thermal synchrotron emission dominates the X-ray spectrum. The non-thermal emission is due to the cosmic-ray electrons accelerated behind the blast wave. The X-ray synchrotron emission is due to the highest energy electrons, and is thus a tracer of the maximum energy electrons may reach behind a shock. We have put together all XMM-Newton observations to build a full map of SN 1006. The very low brightness above 2 keV in the interior indicates that the bright non-thermal limbs are polar caps rather than an equator. This implies that the ambient magnetic field runs southwest to northeast, along the Galactic plane. We used a combined VLA/Parkes radio map to anchor the spectrum at low energy, and model the spectra with synchrotron emission from a cut-off power-law electron distribution, plus a thermal component. We present radial and azimuthal profiles of the cut-off frequency. The cut-off frequency decreases steeply with radius towards the center and with position angle away from the maximum emission. The maximum energy reached by accelerated particles, as well as their number, must be higher at the bright limbs than elsewhere. This implies interesting constraints for acceleration at perpendicular shocks. Overall the XMM-Newton data is consistent with the model in which the magnetic field is amplified where acceleration is efficient.