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arXiv 1404.0889astro-ph.HE
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未识别的gamma-ray源HESS J1507-622的环境

The environment of the unidentified gamma-ray source HESS J1507-622

Wilfried F. Domainko

摘要:

伽马射线源HESS J1507-622位于银河系平面的显著偏移位置,其性质至今尚未确定。识别神秘物体的环境可能有助于限制其性质。HESS J1507-622的视线通过银河系的路径与不同年龄的恒星星族的特征长度尺度进行了比较。此外,对于该对象,将粒子中的能量密度与磁场能量密度进行对比,并且计算基于这两个分量之间的均分的距离的约束。HESS J1507-622的视线到达银河系中心的最小距离约为5.3 kpc,距离银河系圆盘约300 pc。这个位置与年龄为1.2 Gyr的恒星的尺度长度和宽度相吻合,原则上这可能表明HESS J1507-622与年龄相似的恒星星族有关。在这种情况下,源似乎是强粒子主导的。在轻子情形下,如果假设源中的磁场为1 $μ$ G,则磁场与粒子之间的均分将在>1 Mpc的距离处实现。这可能表明该物体的银河系外起源。然而,银河系外起源受到源的延伸的挑战。HESS J1507-622的环境仍然难以捉摸。对于该源属于新类别的伽马射线发射器的情况,相关物体(如果存在)的分布可能有助于确定相应的环境和距离尺度。

英文摘要:

The nature of the gamma-ray source HESS J1507-622 that is located significantly off-set from the Galactic plane is not ascertained to date. Identifying the environment of an enigmatic object may help to constrain its nature. The path of the line of sight of HESS J1507-622 through the Galaxy is compared to the characteristic length scales of stellar populations of different ages. Furthermore, for this object, the energy density in particles is contrasted to the magnetic field energy density and constraints on the distance based on equipartition between these two components are calculated. The line of sight of HESS J1507-622 reaches a minimum distance to the Galactic center at around a galactocentric distance of 5.3 kpc at about 300 pc off the Galactic disc. This location coincides with the scale length and width of stars with an age of 1.2 Gyr which could in principle be an indication that HESS J1507-622 is connected to a stellar population of similar age. For such a case the source appears to be strongly particle dominated. In a leptonic scenario, if a magnetic field in the source of 1 $μ$G is assumed, equipartition between magnetic field and particles would be realized at a distance of >1 Mpc. This could indicate an extragalactic origin of this object. However, an extragalactic origin is challenged by the extension of the source. The environment of HESS J1507-622 still remains elusive. For the case where this source belongs to a new class of gamma-ray emitters, the distribution of related objects (if existing) may help to settle the respective environment and distance scale.

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。

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