标题： 3C254和3C280射电源的团块环境约束及热点磁场强度 显示英文标题

标题： Constraints on the Cluster Environments and Hot Spot Magnetic Field Strengths of the Radio Sources 3C254 and 3C280

摘要： 我们介绍了新的钱德拉天文台观测数据，并结合存档的哈勃太空望远镜和无线电观测数据，对位于红移 z=0.734 的射电类星体 3C254 和位于红移 z=0.996 的射电星系 3C280 进行了研究。 我们报告了在 3C280 的射电热点中检测到 X 射线和可能的哈勃太空望远镜光学对应体，以及在 3C254 的射电热点中检测到 X 射线对应体。 我们提出了关于 X 射线团簇的存在性和射电热点内外磁场强度的限制。 钱德拉的高空间分辨率使我们能够表明这些源并不处于高温、大质量的团簇中。 在 ROSAT 观测中看到的扩展辐射被解析为点源。 这些源周围的 IGM 明显不密集且不热。 我们得出结论，射电源在中等红移处并不是大质量团簇的可靠标志。 同步辐射的 X 射线发射可以解释 3C280 中射电、光学和 X 射线热点的通量，但这需要电子持续加速至高洛伦兹因子，因为产生 X 射线所需的同步辐射寿命大约相当于人类的寿命。 具有或不具有 CMB 散射的 SSC 也可以解释 X 射线发射，但不能解释光学发射。 我们回顾了所有物理机制，并总结了我们目前对 3C254 和 3C280 热点内外磁场强度的限制。 显示英文摘要

摘要： We present new Chandra Observatory observations with archival HST and radio observations of 3C254, a radio quasara at z=0.734, and 3C280, a radio galaxy at z=0.996. We report the detection of X-ray and possible HST optical counterparts to the radio hot spots in 3C280 and of an X-ray counterpart to the radio hot spot in 3C254. We present constraints on the presence of X-ray clusters and on the magnetic field strengths in and around the radio hot spots. The spatial resolution of Chandra allows us to show that these sources are not in hot, massive clusters. The extended emission seen in ROSAT observations is resolved into point sources. The IGM around these sources is demonstrably not dense and hot. We conclude that radio sources are not reliable signposts of massive clusters at moderate redshifts. X-ray synchrotron emission could explain the radio, optical, and X-ray hot spot fluxes in 3C280, but it would require continuous acceleration of electrons to high Lorentz factors, since the synchrotron lifetime required to produce the X-ray emission is of order a human lifetime. SSC with or without IC scattering of the CMB can also explain the X-ray emission, but not the optical. We review all of the physical mechanisms and summarize our current constraints on the magnetic field strengths in andaround the hot spots of 3C254 and 3C280.