We present HI observations of the Sculptor Group starburst spiral galaxy NGC 253, obtained with the Karoo Array Telescope (KAT-7). KAT-7 is a pathfinder for the SKA precursor MeerKAT, under construction. The short baselines and low system temperature of the telescope make it very sensitive to large scale, low surface brightness emission. The KAT-7 observations detected 33% more flux than previous VLA observations, mainly in the outer parts and in the halo for a total HI mass of $2.1 \pm 0.1$ $\times 10^{9}$ M$_{\odot}$. HI can be found at large distances perpendicular to the plane out to projected distances of ~9-10 kpc away from the nucleus and ~13-14 kpc at the edge of the disk. A novel technique, based on interactive profile fitting, was used to separate the main disk gas from the anomalous (halo) gas. The rotation curve (RC) derived for the HI disk confirms that it is declining in the outer parts, as seen in previous optical Fabry-Perot measurements. As for the anomalous component, its RC has a very shallow gradient in the inner parts and turns over at the same radius as the disk, kinematically lagging by ~100 km/sec. The kinematics of the observed extra planar gas is compatible with an outflow due to the central starburst and galactic fountains in the outer parts. However, the gas kinematics shows no evidence for inflow. Analysis of the near-IR WISE data, shows clearly that the star formation rate (SFR) is compatible with the starburst nature of NGC 253.
Tracing Cold Gas in Absorption Across Cosmic Time with the SKA
Inter-University Centre for Astronomy and Astrophysics（天文与天体物理跨大学中心）；Ioffe Institute（约费研究所）；Indian Institute of Astrophysics (IIA)（印度天体物理研究所）；Centre for Astrophysics and Supercomputing, Swinburne University of Technology（天体物理学与超级计算中心，斯威本科技大学）；French-Chilean Laboratory for Astronomy, IRL 3386, CNRS and Universidad de Chile（法智利天体物理实验室，IRL 3386，法国国家科学研究中心和智利大学）；National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；Wits Centre for Astrophysics, School of Physics, University of the Witwatersrand（维特沃特斯兰德大学物理学院天体物理中心）；Institut d'Astrophysique de Paris, CNRS（巴黎天体物理研究所，法国国家科学研究中心）；Pole Scientific, University Catholic of Lyon（里昂天主教大学科学学部）；Sydney Institute for Astronomy, School of Physics A28, University of Sydney（悉尼大学物理学院A28天文研究所）；Astronomy Department, National Research Institute of Astronomy and Geophysics (NRIAG)（天体物理与地球物理国家研究所天文系）；International Centre for Radio Astronomy Research, Curtin University（科廷大学国际射电天文研究中心）；Korea Astronomy and Space Science Institute（韩国天文学与空间科学研究院）
YOLO-CIANNA: Galaxy detection with deep learning in radio data: II. Winning the SKA SDC2 using a generalized 3D-YOLO network
LUX, Observatoire de Paris, Université PSL, Sorbonne Université, CNRS（巴黎天文台卢克斯实验室，巴黎文理研究大学，索邦大学，法国国家科学研究中心）；Canadian Institute for Theoretical Astrophysics, University of Toronto（加拿大理论天体物理研究所，多伦多大学）；Research School of Astronomy & Astrophysics, Australian National University（澳大利亚国立大学天文与天体物理研究学院）；Université de Strasbourg, CNRS UMR 7550, Observatoire astronomique de Strasbourg（斯特拉斯堡大学，法国国家科学研究中心UMR 7550，斯特拉斯堡天文台）；DIO, Observatoire de Paris, CNRS, PSL（巴黎天文台数据与信息办公室，法国国家科学研究中心，巴黎文理研究大学）；IDRIS, CNRS（法国国家科学研究中心集成系统研究所）；Collège de France（法兰西公学院）；Department of Physics & Electronics, Rhodes University（罗兹大学物理与电子系）
Low-Frequency Recombination Lines from Galaxies and AGN over Cosmic Time
Ioffe Institute（约费研究所）；Laboratoire de Physique de l’École Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne University, University Paris Cité（巴黎高等师范学院物理实验室，ENS，巴黎文理研究大学，法国国家科学研究中心，索邦大学，巴黎西岱大学）；Inter-University Centre for Astronomy and Astrophysics（大学天文学与天体物理学中心）；Chalmers University of Technology, Onsala Space Observatory（查尔姆斯理工大学，翁萨拉太空观测站）；Sydney Institute for Astronomy, School of Physics A28, University of Sydney（悉尼天文研究所，A28物理学院，悉尼大学）；University of Maryland（马里兰大学）；University of Virginia（弗吉尼亚大学）
Rhodes University（罗德斯大学）；Queen’s University（女王大学）；Arthur B. McDonald Canadian Astroparticle Physics Research Institute, Queen’s University（亚瑟·B·麦克唐纳加拿大高能粒子物理研究所，女王大学）；IFPU – Institute for Fundamental Physics of the Universe（宇宙基础物理研究所 (IFPU)）；Seoul National University（首尔大学）；The University of Western Australia（西澳大学）
