...
首页> 外文期刊>The Astrophysical journal >THE RADIO CONTINUUM STRUCTURE OF CENTAURUS A AT 1.4?GHz
【24h】

THE RADIO CONTINUUM STRUCTURE OF CENTAURUS A AT 1.4?GHz

机译:在1.4?GHz处CENTURARUS A的无线电连续体结构

获取原文
           

摘要

A 45 deg2 radio continuum imaging campaign of the nearest radio galaxy, Centaurus A, is reported. Using the Australia Telescope Compact Array and the Parkes 64?m radio telescope at 1.4?GHz, the spatial resolution of the resultant image is ~600?pc (~50''), resolving the 500?kpc giant radio lobes with approximately five times better physical resolution compared to any previous image, and making this the most detailed radio continuum image of any radio galaxy to date. In this paper, we present these new data and discuss briefly some of the most interesting morphological features that we have discovered in the images. The two giant outer lobes are highly structured and considerably distinct. The southern part of the giant northern lobe naturally extends out from the northern middle lobe with uniformly north-streaming emission. The well known northern loop is resolved into a series of semi-regular shells with a spacing of approximately 25?kpc. The northern part of the giant northern lobe also contains identifiable filaments and partial ring structures. As seen in previous single-dish images at lower angular resolution, the giant southern lobe is not physically connected to the core at radio wavelengths. Almost the entirety of the giant southern lobe is resolved into a largely chaotic and mottled structure which appears considerably different (morphologically) to the diffuse regularity of the northern lobe. We report the discovery of a vertex and a vortex near the western boundary of the southern lobe, two striking, high surface brightness features that are named based on their morphology and not their dynamics (which are presently unknown). The vortex and vertex are modeled as reaccelerated lobe emission due to shocks from the active galactic nucleus itself or from the passage of a dwarf elliptical galaxy through the lobe. Preliminary polarimetric and spectral index studies support a plasma reacceleration model and could explain the origin of the Faraday rotation structure detected in the southern lobe. In addition, there are a series of low surface brightness wisps detected around the edges of both the giant lobes.
机译:据报道,最近的射电星系Centaurus A进行了45度2射电连续成像。使用澳大利亚望远镜紧凑阵列和1.4?GHz的Parkes 64?m射电望远镜,所得图像的空间分辨率为〜600?pc(〜50''),以大约五倍的分辨率解决了500?kpc的巨大射电瓣。与以前的任何图像相比,它的物理分辨率更高,并且使之成为迄今为止所有射电星系中最详尽的射电连续体图像。在本文中,我们介绍了这些新数据,并简要讨论了我们在图像中发现的一些最有趣的形态特征。两个巨大的外部裂片高度结构化并且截然不同。北部大叶的南部自然地从北部中叶向外延伸,并向北均匀排放。众所周知的北部环路被分解成一系列间隔约25kkpc的半规则壳。北部巨叶的北部也包含可识别的细丝和部分环状结构。从以前的单碟图像中可以看到,在较低的角分辨率下,巨大的南瓣在无线电波长处未物理连接到核心。几乎整个南部巨叶都被分解成一个杂乱无章,杂乱无章的结构,这在形态上与北部的扩散规律性大不相同。我们报告了在南叶西边界附近发现一个顶点和一个涡旋的发现,这两个惊人的,高表面​​亮度特征是根据其形态而不是其动力学来命名的(目前未知)。由于活动银河原子核本身或矮椭圆形星系穿过该叶所产生的冲击,涡旋和顶点被建模为再加速的叶发射。初步的极化和光谱指数研究支持等离子再加速模型,并且可以解释在南部叶中检测到的法拉第旋转结构的起源。此外,在两个大瓣的边缘附近都检测到一系列低表面亮度的小束。
获取原文

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号