致密射电源0223+341和0248+430的毫角秒尺度偏振研究
VLBI Polarization Study of Compact Radio Sources 0223+341 and 0248+430
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摘要: 利用美国甚长基线干涉阵(Very Long Baseline Array, VLBA),对致密射电源0223+341和0248+430进行了4.6GHz的偏振观测,获得了角分辨率高达2毫角秒的辐射强度分布图像,并首次得到这两个射电源在4.6GHz的偏振矢量分布结果。其中致密陡谱(Compact Steep Spectrum, CSS)源0223+341未观测到射电核,射电结构主要由两个疑似热斑的成分组成,偏振辐射集中在其中一个热斑处,偏振度较低,周围可能有较浓密的介质;而吉赫兹峰谱(Gigahertz Peaked Specturm, GPS)源0248+430呈现单侧核-喷流结构,偏振辐射集中在射电核附近。Abstract: Using the Very Long Baseline Array, we perform the polarization observations of the compact radio source 0223+341 and 0248+430 at 4.6GHz. We present their mas-resolution total intensity maps, and for the first time, their polarization maps at 4.6GHz. The compact steep spectrum source 0223+341 has no detectable radio core. Its jet structure mainly consists of two extended components, which may be explained as the hot spots in the kpc-scale radio lob. The polarization emission is firmly detected in a region near the northern component. Given that the polarization degree of 0223+341 is very low, there may be dense medium around the jet components. The other sources 0248+430 is a GHz-peaked spectrum source and displays one-sided core-jet structure. Polarized emission is found near its jet base.
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