We study the mutual alignment of radio sources within two surveys, FIRST and TGSS. This is done by producing two position angle catalogues containing the preferential directions of respectively $30\,059$ and $11\,674$ extended sources distributed over more than $7\,000$ and $17\,000$ square degrees. The identification of the sources in the FIRST sample was performed in advance by volunteers of the Radio Galaxy Zoo project, while for the TGSS sample it is the result of an automated process presented here. After taking into account systematic effects, marginal evidence of a local alignment on scales smaller than $2.5°$ is found in the FIRST sample. The probability of this happening by chance is found to be less than $2$ per cent. Further study suggests that on scales up to $1.5°$ the alignment is maximal. For one third of the sources, the Radio Galaxy Zoo volunteers identified an optical counterpart. Assuming a flat $Λ$CDM cosmology with $Ω_m = 0.31, Ω_Λ= 0.69$, we convert the maximum angular scale on which alignment is seen into a physical scale in the range $[19, 38]$ Mpc $h_{70}^{-1}$. This result supports recent evidence reported by Taylor and Jagannathan of radio jet alignment in the $1.4$ deg$^2$ ELAIS N1 field observed with the Giant Metrewave Radio Telescope. The TGSS sample is found to be too sparsely populated to manifest a similar signal.
Zooming in on radio relics -- II. How relic morphology probes density fluctuations at the edge of galaxy clusters
Leibniz-Institut für Astrophysik Potsdam (AIP)（波茨坦莱布尼茨天体物理研究所）；Max-Planck-Institut für Astrophysik（马克斯·普朗克天体物理研究所）；Universität Potsdam（波茨坦大学）；Universität Heidelberg（海德堡大学）
Spin alignments of spiral galaxies within the large-scale structure from SDSS DR7
利用Sloan数字巡天数据发布7（SDSS DR 7）和星系动物园2（GZ 2）中的一组旋涡星系，研究了旋涡星系的自旋轴与周围大尺度结构的排列，其特征是利用一定质量阈值以上的星系群数据重建的大尺度潮汐场.我们发现，只有自旋轴有微弱的倾向，是对齐（或垂直于）本地潮汐张量的中（或短）轴。信号是最强的\cluster环境中的所有三个特征值的本地潮汐张量是积极的。与N体模拟中得到的晕自旋与局域潮汐场的一致性相比，上述观测结果与晕内区自旋的一致性最好，表明盘物质追踪了内区暗物质晕的角动量.
CO survey of high-z radio galaxies, revisited with ALMA: Jet-cloud Alignments and Synchrotron Brightening by Molecular Gas in the Circumgalactic Environment
How to augment cosmic shear measurements with radio polarimetry of galaxies?
University of California（加州大学）；Perimeter Institute for Theoretical Physics（珀尔默特理论物理研究所）；University of Melbourne（墨尔本大学）；Lawrence Berkeley National Laboratory（劳伦斯伯克利国家实验室）
