We present results from a study of seven large known head-tail radio galaxies based on observations using the Giant Metrewave Radio Telescope at 240 and 610 MHz. These observations are used to study the radio morphologies and distribution of the spectral indices across the sources. The overall morphology of the radio tails of these sources is suggestive of random motions of the optical host around the cluster potential. The presence of the multiple bends an d wiggles in several head-tail sources is possibly due to the precessing radio jets. We find steepening of the spectral index along the radio tails. The prevailing equipartition magnetic field also decreases a long the radio tails of these sources. These steepening trends are attributed to the synchrotron aging of plasma toward the ends of the tails. The dynamical ages of these sample sources have been estimated to be ~100 Myr, which is a factor of six more than the age estimates from the radiative losses due to synchrotron cooling.
Head-Tail Clouds: Drops to Probe the Diffuse Galactic Halo
头-尾高速云(HVC)是一种中性氢晕云,它似乎与扩散晕介质相互作用,这一点可以从其压缩的头部和相对扩散的尾部看出。本文给出了来自HI-Parkes全巡天(HIPASS)HVC星表的116个南天(d < 2 deg)头尾型HVC样本,该星表的空间分辨率为15.5弧分(45 pc at 10 kpc),灵敏度为NHI =2 x 10^(18)cm^(-2)(5 sigma)。35%的HIPASS致密和半致密HVC(CHVC和:HVC)可以从它们的形态分类为头-尾云。这些云在10千秒差距时的典型质量为730 M_sun(60千秒差距时为26,000 M_sun),考虑到它们在空间和运动学上的接近性,大多数云可能与更大的HVC复合体有关。这种接近性,加上它们与CHVC和没有头尾结构的HVC相似的性质,表明头尾云的寿命很短,与模拟预测一致。大约有一半的头尾云可以与麦哲伦星系联系在一起,其中大部分位于主导臂的区域,位置角指向麦哲伦星系运动的大致方向。在引导臂区域的丰度是一致的,这一特点是更接近银河系盘比麦哲伦流和通过一个更密集的晕介质移动。头-尾云将直接供给多相晕介质,而不是银河系盘,并为扩散的星系晕介质至少延伸到麦哲伦云的距离提供额外的证据。
A new catalogue of head-tail radio galaxies from LoTSS DR1
头-尾(HT)射电星系的独特形态表明,射电喷流和它们的星系团内介质强烈相互作用。我们使用LOFAR两米巡天首次发布的144 MHz数据(LoTSS DR 1)对HT射电星系进行了系统的搜索。本文给出了一个包含55个新HT射电星系的星表,其中10个是窄角尾源(NAT),45个是广角尾源(WATS)。NAT的特点是尾部弯曲成一个狭窄的“V”形,开口角度小于90度。WAT射电星系喷流之间的张开角大于90度,呈现出宽的“C”状形态。我们发现,在这篇文章中报道的55个HT射电星系中,有30个与已知的星系团有关。本文中介绍的大多数源的红移为$<$ 0.5。介绍了这些HT射电星系的各种物理性质和统计研究。
Origin and Evolution of the $Ω$ Structure in the Head-Tail Radio Galaxy of Abell 3322
National Astronomical Observatory of Japan(日本国立天文台);Kobayashi-Maskawa Institute for the Origin of Particles and the Universe (KMI), Nagoya University(名古屋大学小林益川粒子与宇宙起源研究所);Institute for Cosmic Ray Research, The University of Tokyo(东京大学宇宙射线研究所);Division of Science, National Astronomical Observatory of Japan(日本国立天文台理学科);Departure of Physics, Nagoya University(名古屋大学物理学部);Max Planck Institute for Radio Astronomy(马克斯·普朗克射电天文研究所);Graduate School of Science and Technology for Innovation, Yamaguchi University(山口大学创新理工学研究科);Department of Physics, Yamagata University(山形大学物理学系)
A Gamma-ray Emitting Head-Tail Radio Galaxy Swimming Through the Hot Medium of the Merging Cluster Abell 3627
Inter-University Centre for Astronomy and Astrophysics (IUCAA)(天文与天体物理大学间中心);Centre for Space Research, North-West University(西北大学太空研究中心);International Gemini Observatory/NSF NOIRLab(国际双星观测台/美国国家光学红外天文实验室);Indian Institute of Astrophysics(印度天体物理研究所);Universität Bielefeld(比勒费尔德大学);Assam Don Bosco University(阿萨姆唐博斯科大学);Dayanand Science College(戴亚南德科学学院)
Radiation-Driven Evolution and Gas Kinematics of the Bright-Rimmed Cloud SFO 25
Indian Institute of Astrophysics(印度天体物理研究所);Pondicherry University(本地治里大学);NSF’s NOIRLab(美国国家科学基金会NOIR天文台实验室);Department of Physics and Astronomy, University College London(伦敦大学学院物理与天文系)
Head-tail molecular clouds falling onto the Milky Way disk
Nagoya City Science Museum(名古屋市科学馆);Department of Physics, Graduate School of Science, Nagoya University(名古屋大学理学研究科物理学系);Faculty of Engineering, Gifu University(岐阜大学工学部);Department of Earth Science and Astronomy, Graduate School of Arts and Sciences, The University of Tokyo(东京大学大学院人文社会系研究科地球惑星科学专攻);Faculty of Education, Kagawa University(香川大学教育学部);Center for Space Research and Utilization Promotion (c-SRUP), Gifu University(岐阜大学宇宙利用促进研究中心);Institute of Statistical Mathematics(数理统计学研究所);National Astronomical Observatory of Japan (NAOJ), National Institutes of Natural Sciences (NINS)(日本国立天文台(隶属于自然科学研究机构));Department of Physics, Faculty of Science, Hokkaido University(北海道大学理学部物理学系);Institute for Advanced Study, Gifu University(岐阜大学高等研究院);Institute for Advanced Research, Nagoya University(名古屋大学高等研究院);Nobeyama Radio Observatory, National Astronomical Observatory of Japan (NAOJ), National Institutes of Natural Sciences (NINS)(野边山无线电天文台(隶属于日本国立天文台,自然科学研究机构));National Institute for Fusion Science (NIFS)(核聚变科学研究所)