Radio Continuum Observations of the Virgo Cluster Spiral NGC 4522: The Signature of Ram Pressure
Radio Continuum Observations of the Virgo Cluster Spiral NGC 4522: The Signature of Ram Pressure
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处女座星团螺旋 NGC 4522 的射电连续观测：冲压压力的特征
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发表时间：
2004
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影响因子：
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通讯作者：
New York.
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文献类型：
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作者：
B. Vollmer;R. Beck;J. Kenney;J. V. G. Cds;O. Strasbourg;France;M. F. Radioastronomie;Bonn;Germany;Yale University;New Haven;Usa;C. University;New York.
本文介绍了室女座大倾角螺旋星系NGC 4522在20和6厘米波段的射电连续观测结果。20 cm和6 cm的总辐射分布都是不对称的，并有一个向西延伸的分量，在那里发现了面外原子气体和Hα辐射，6 cm偏振辐射位于银盘的东边缘。它的峰值位于总发射峰以东约1kpc处。我们认为，这种现象是一个典型的功能，正在经历显着的压力，从集群内介质的星系团。因此，偏振射电连续辐射是探测螺旋星系与星系团ICM相互作用的有力工具。偏振度由东向西逐渐减小。在20和6cm之间的最平坦的光谱指数与6cm偏振发射的峰值相一致。这些发现与位于星系东部宇宙射线加速的冲压压力造成的大规模冲击的图片一致。我们的结论是，银河系很可能经历了活跃的冲压压力。
Radio continuum observations at 20 and 6 cm of the highly inclined Virgo spiral galaxy NGC 4522 are presented. Both 20 and 6 cm total emission distributions are asymmetric with an extended component to the west, where extraplanar atomic gas and Hα emission are found. The 6 cm polarized emission is located at the eastern edge of the galactic disk. Its peak is located about 1 kpc to the east of the total emission peak. We argue that this phenomena is a characteristic feature for cluster galaxies that are experiencing significant pressure from the intracluster medium. Polarized radio continuum emission is thus a powerful tool to detect interactions of spiral galaxies with the cluster ICM. The degree of polarization decreases from the east to the west. The flattest spectral index between 20 and 6 cm coincides with the peak of the 6 cm polarized emission. These findings are consistent with a picture of a large-scale shock due to ram pressure located at the east of the galaxy where cosmic rays are accelerated. We conclude that it is likely that the galaxy experiences active ram pressure.