We have mapped NGC 3718, a nearby bright galaxy in a loose group, and its companion NGC 3729 in the 21cm line of neutral hydrogen. NGC 3718 is a strikingly unusual galaxy with a strong straight dust lane across the center, peculiar diffuse spiral arms, and an extended disk of neutral hydrogen. Earlier work showed the gas disk to be strongly twisted, warping through edge-on where we see the straight dust lane; stars formed in this gas appear to make up the 'spiral arms'. Our improved maps show a twisted but bisymmetric disk of gas extending to 7arcmin or 35kpc, where the orbital period is roughly 1Gyr. It is surrounded by fragmentary spiral features, and a streamer of gas extending to a cloud lying 12arcmin or 60kpc to the north. We use INSPECTOR, a task in GIPSY, to fit a tilted-ring model interactively to slices through the HI data cube. The apparent major axis swings through 100 degrees from the innermost gas orbits at 30arcsec radius to the outer edge. When viewed in the reference frame of the galaxy's stellar disk, the innermost gas orbits are nearly polar, while the outer rings of gas are tilted at 30-40 degrees. The line of nodes, where the gas orbits pass through the plane of the stellar disk, twists by roughly 90 degrees about the pole. We do not see gas orbiting in the plane of the stellar disk. If we assume that the galaxy's dark halo shares the same midplane, then the observed twist can be explained by differential precession in a dynamical model in which the dark halo is fairly round. The run of tilt with radius is close to what is required for the warped gas disk to precess rigidly in the galaxy's gravitational field without changing its shape. This fact probably accounts for the longevity of the twisted structure.
The Fundamental Plane Is Not a Plane: Warped Nature of the Fundamental Plane of Early-type Galaxies and Its Implication for Galaxy Formation
基于Sloan数字巡天观测数据中$0.025\le z_\mathrm{spec}<0.055$中的$16,283$早型星系（ETGs），我们证明了ETGs的基面（FP）不是严格意义上的平面，而是一个扭曲的曲面，其垂直于表面的方向随着中心速度色散（$σ_0$）或半光半径内平均表面亮度（$μ_e$）的变化而改变.当ETG根据$σ_0$划分为子样本时，FP的$μ_e$系数增加，而FP的零点在较高的$σ_0$处减小。以$z$频带为例，随着$σ_0$从$\sim100$增加到$\sim300$ km s $^{-1}$，$μ_e$的系数从$0.28$增加到$0.36$。同时，FP的零点从$-7.5$下降到相同$σ_0$范围内的$-9.0$。通过检查具有不同$μ_e$的ETG子样本的FP系数的变化，也达到了关于FP的弯曲性质的一致图片。通过检查尺度关系的FP的预测，我们认为，扭曲的性质的FP可能源于干合并的影响，更突出地印在ETG具有较高的质量。
Redshifted Cool Gas in the Disturbed HI Disk of the Starburst Dwarf NGC 4214
Xiamen University（厦门大学）；Fujian Business University（福建商学院）；Università degli Studi di Firenze（佛罗伦萨大学）；INAF - Osservatorio Astrofisico di Arcetri（意大利国家天体物理研究所阿切特里天文台）；National Astronomical Observatories, Chinese Academy of Sciences (NAOC)（中国科学院国家天文台）；Guizhou Radio Astronomical Observatory（贵州天文观测站）；Guizhou Provincial Key Laboratory of Medium and Low Frequency Radio Astronomy Technology and Application（贵州省中低频射电天文技术与应用重点实验室）
MAUVE: Cold neutral gas in the outflow of NGC 4383 and evidence for a fountain flow
International Centre for Radio Astronomy Research, University of Western Australia（西澳大利亚大学国际射电天文研究中心）；University of Kentucky（肯塔基大学）；National Research Council of Canada, Herzberg Astronomy and Astrophysics Research Centre（加拿大国家研究委员会赫茨伯格天体物理学研究中心）；University of Victoria（维多利亚大学）；Aix Marseille Univ, CNRS, CNES, LAM（艾克斯-马赛大学，法国国家科学研究中心，法国国家空间研究中心，拉格朗日天体物理实验室）；Astronomical Institute of the Czech Academy of Sciences（捷克科学院天文研究所）；University of Nottingham（诺丁汉大学）；University of Vienna（维也纳大学）；University of New South Wales（新南威尔士大学）；Universidad Diego Portales（迭戈·波塔莱斯大学）
Population search for dark matter spikes in megamaser rotation curves
Kavli Institute for Astrophysics and Department of Physics, Massachusetts Institute of Technology（麻省理工学院卡弗里天体物理研究所与物理系）；Harvard Laboratory for Particle Physics and Cosmology and Department of Physics, Harvard University（哈佛大学粒子物理与宇宙学实验室与物理系）
