A possible association of the new VHE gamma-ray source HESS J1825-137 with the pulsar wind nebula G 18.0-0.7
A possible association of the new VHE gamma-ray source HESS J1825-137 with the pulsar wind nebula G 18.0-0.7
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新的 VHE 伽马射线源 HESS J1825-137 与脉冲星风星云 G 18.0-0.7 可能存在关联
DOI：
10.1051/0004-6361:200500180
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发表时间：
2005
影响因子：
6.5
通讯作者：
E. al.
中科院分区：
文献类型：
--
作者：
H. C. F. Aharonian;E. al.
我们报道了最近发现的高能γ射线源HESS J1825- 137与2.1 × 10^{4}$年的类船帆座脉冲星PSR B1823- 13的脉冲风星云（通常称为G 18.0- 0.7）的可能关联。在HESS进行的银河平面调查中，检测到HESS J1825--137的显着性为8.1 $\sigma$ 2004年的文书。HESS J1825- 137的质心位置在脉冲星位置以南偏移了11 arcmin。\n {XMM-Newton}观测揭示了延伸到脉冲星南部的不对称脉冲星风星云的X射线同步辐射。我们认为，所观察到的形态和TeV光谱指数表明，HESS J1825- 137和G 18.0- 0.7可能是相关的：TeV发射电子的寿命预计将更长相比，{\it XMM-牛顿} X射线发射电子，导致电子从较早的时代（当自旋下降功率较大）有助于目前的TeV通量。这些电子预计是同步加速器冷却的，这解释了观测到的光子指数为$\sim 2.4$，而TeV发射电子的更长寿命自然解释了为什么TeV星云大于X射线尺寸。最后，超新星遗迹膨胀到一个不均匀的介质中，预计将在不同的时间与脉冲星风星云产生相互作用的反向冲击，导致偏移X射线和TeV $\gamma$-射线形态。
We report on a possible association of the recently discovered very high-energy $\gamma$-ray source HESS J1825--137 with the pulsar wind nebula (commonly referred to as G 18.0--0.7) of the $2.1\times 10^{4}$ year old Vela-like pulsar PSR B1823--13. HESS J1825--137 was detected with a significance of 8.1 $\sigma$ in the Galactic Plane survey conducted with the H.E.S.S. instrument in 2004. The centroid position of HESS J1825--137 is offset by 11\arcmin south of the pulsar position. \emph{XMM-Newton} observations have revealed X-ray synchrotron emission of an asymmetric pulsar wind nebula extending to the south of the pulsar. We argue that the observed morphology and TeV spectral index suggest that HESS J1825--137 and G 18.0--0.7 may be associated: the lifetime of TeV emitting electrons is expected to be longer compared to the {\it XMM-Newton} X-ray emitting electrons, resulting in electrons from earlier epochs (when the spin-down power was larger) contributing to the present TeV flux. These electrons are expected to be synchrotron cooled, which explains the observed photon index of $\sim 2.4$, and the longer lifetime of TeV emitting electrons naturally explains why the TeV nebula is larger than the X-ray size. Finally, supernova remnant expansion into an inhomogeneous medium is expected to create reverse shocks interacting at different times with the pulsar wind nebula, resulting in the offset X-ray and TeV $\gamma$-ray morphology.