The gas density around SN 1006
The gas density around SN 1006
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DOI：
10.1051/0004-6361:20077742
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发表时间：
2007-09
期刊：
影响因子：
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通讯作者：
F. Acero;J. Ballet;A. Decourchelle
中科院分区：
文献类型：
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作者：
F. Acero;J. Ballet;A. Decourchelle
超新星遗迹演化的环境介质密度是其流体动力学演化、粒子加速机制以及 TeV 能量发射的相关参数。利用 XMM-牛顿 X 射线观测，我们对历史超新星遗迹 SN 1006 的环境介质密度进行了研究。我们对震后热发射进行了建模，以约束环境介质密度。我们的研究重点是遗迹的西北和东南边缘，这里的热辐射占主导地位。我们使用了平面平行激波等离子体模型以及在我们研究区域中不可忽略的喷射物的另一个组件。还研究了同步加速器组件的重要性。为了改进统计数据，我们结合了对残余物的几次观察。东南边缘发现的密度较低，大约为 0.05 cm-3，似乎可以代表其余的遗迹。然而，在西北边缘（靠近明亮的光纤丝），密度明显更高（约0.15-0.25 cm-3）。这证实了 SN 1006 在稀薄的环境介质中演化的景象，除了在西北地区，残余物最近遇到了更密集的区域。如此低的密度与 HESS 伽马射线天文台无法检测到残余物是相容的。东南部密度较低意味着冲击速度较高，为 4900 公里/秒，高于西北地区测量的 2890 公里/秒。这种对速度的新估计可以将加速粒子可以达到的最大能量提高到约 1 PeV。
The density of the ambient medium where the supernova remnant evolves is a relevant parameter for its hydrodynamical evolution, for the mechanism of particle acceleration, and for the emission at TeV energies. Using XMM-Newton X-ray observations, we present a study of the ambient medium density of the historical supernova remnant SN 1006. We modelled the post-shock thermal emission to constrain the ambient medium density. Our study is focused on the North-West and the South-East rims of the remnant, where the thermal emission dominates. We used a plane-parallel shock plasma model plus another component for the ejecta that are not negligible in the regions of our study. The importance of the synchrotron component is also studied. In order to improve statistics, we combined several observations of the remnant. The density found in the South-East rim is low, roughly 0.05 cm-3, and seems to be representative of the rest of the remnant. However, in the North-West rim (close to the bright optical filament), the density is significantly higher (about 0.15-0.25 cm-3). This confirms a picture of SN 1006 evolving in a tenuous ambient medium, except in the North-West where the remnant has recently encountered a denser region. A density this low is compatible with the non-detection of the remnant by the HESS gamma-ray observatory. The lower density in the South-East implies a higher shock speed of 4900 km/s, higher than that of 2890 km/s measured in the North-West. This new estimate of the velocity could increase the maximum energy that accelerated particles can reach to energies of about 1 PeV.