F. Combes, N. Gupta, S. Muller, S. Balashev, P. Deka, K. Emig, H. -R. Kloeckner, D. Klutse, K. Knowles, A. Mohapatra, E. Momjian, P. Noterdaeme, P. Petitjean, P… 展开作者
F. Combes, N. Gupta, S. Muller, S. Balashev, P. Deka, K. Emig, H. -R. Kloeckner, D. Klutse, K. Knowles, A. Mohapatra, E. Momjian, P. Noterdaeme, P. Petitjean, P. Salas, R. Srianand, J. Wagenveld
The BL Lac PKS 1413+135 was observed by the Large Survey Project "MeerKAT Absorption Line Survey" (MALS) in the L-band, at 1139 MHz and 1293-1379 MHz, targeting the HI and OH lines in absorption at z = 0.24671. The radio continuum is thought to come from a background object at redshift lower than 0.5, as suggested by the absence of gravitational images. The HI absorption line is detected at high signal-to-noise, with a narrow central component, and a red wing, confirming previous results. The OH 1720 MHz line is clearly detected in (maser) emission, peaking at a velocity shifted by -10 to -15 km/s with respect to the HI peak. The 1612 MHz line is lost due to radio interferences. The OH 1667 MHz main line is tentatively detected in absorption, but not the 1665 MHz one. Over 30 years, a high variability is observed in optical depths, due to the rapid changes of the line of sight, caused by the superluminal motions of the radio knots. The HI line has varied by 20 per cent in depth, while the OH-1720 MHz depth has varied by a factor 4. The position of the central velocity and the widths also varied. The absorbing galaxy is an early-type spiral (maybe S0) seen edge-on, with a prominent dust lane, covering the whole disk. Given the measured mass concentration, and the radio continuum size at centimeter wavelengths (100 mas corresponding to 400 pc at z = 0.25), the width of absorption lines from the nuclear regions are expected up to 250 km/S. The narrowness of the observed lines (< 15 km/s) suggest that the absorption comes from an outer gas ring, as frequently observed in S0 galaxies. The millimetric lines are even narrower (< 1 km/s), which corresponds to the continuum size restricted to the core. The core source is covered by individual 1 pc molecular clouds, of column density a few 10^22 cm-2, which is compatible with the gas screen detected in X-rays.
An HI+radio continuum study of local cluster galaxies: Intercepting the early stages of environmental processing with MeerKAT
INAF - Osservatorio Astronomico di Padova（意大利国家天体物理研究所帕多瓦天文台）；Astronomical Institute of the Czech Academy of Sciences（捷克科学院天文研究所）；INAF - Osservatorio Astronomico di Cagliari（意大利国家天体物理研究所卡利亚里天文台）；University of Bologna（博洛尼亚大学）；INAF - Istituto di Radioastronomia（意大利国家天体物理研究所射电天文研究所）；ESO（欧洲南方天文台）；Leibniz Institute for Astrophysics Potsdam (AIP)（波茨坦市莱布尼兹天体物理研究所）；Centre for Radio Astronomy Techniques and Technologies (RATT), Department of Physics and Electronics, Rhodes University（罗德斯大学物理与电子学院射电天文技术与方法中心）；Institute for Fundamental Physics of the Universe（宇宙基础物理研究所）；SISSA - International School for Advanced Studies（国际高等研究院）；INAF - Osservatorio Astronomico di Trieste（意大利国家天体物理研究所的里雅斯特天文台）
A new look at old devils. II: New insights on classical radio galaxies from MeerKAT and uGMRT
University of South Africa（南非大学）；INAF—Istituto di Radioastronomia（意大利国家天体物理研究所射电天文台）；Centre for Radio Astronomy Techniques and Technologies (RATT), Department of Physics and Electronics, Rhodes University（罗德斯大学物理与电子学院射电天文技术与方法中心）；National Centre for Radio Astrophysics, Tata Institute of Fundamental Research（塔塔基础研究院国家射电天体物理中心）；South African Radio Astronomy Observatory（南非射电天文观测站）；Naval Research Laboratory（海军研究实验室）
uGMRT and MeerKAT observation of RXCJ0232-4420: a quiet cluster with a giant radio halo
National Centre for Radio Astrophysics, Tata Institute of Fundamental Research（塔塔基础研究院国家射电天文中心）；International Centre for Theoretical Sciences, Tata Institute of Fundamental Research（塔塔基础研究院国际理论科学中心）；National Radio Astronomy Observatory (NRAO)（国家射电天文台）
MeerKAT discovery of a high-redshift strongly-lensed hydroxyl gigamaser
University of Pretoria（比勒陀利亚大学）；Wits Centre for Astrophysics, University of the Witwatersrand（威特沃特斯兰德大学天体物理中心）；Rhodes University（罗德岛大学）；South African Radio Astronomy Observatory（南非射电天文台）；SKA Observatory（平方公里阵列望远镜观测站）；University of Oxford（牛津大学）；University of Illinois at Urbana-Champaign（伊利诺伊大学厄巴纳-香槟分校）
The MeerKAT 1.3 GHz Survey of the Large Magellanic Cloud
National Radio Astronomy Observatory（国家无线电天文台）；South African Radio Astronomy Observatory（南非无线电天文台）；Western Sydney University（西悉尼大学）；Faculty of Engineering, Gifu University（岐阜大学工程学院）；Centre for Radio Astronomy Techniques and Technologies (RATT), Department of Physics and Electronics, Rhodes University（罗德斯大学物理与电子学院射电天文技术与方法中心）；Institute for Radio Astronomy, National Institute of Astrophysics (INAF IRA)（意大利国家天体物理研究所射电天文研究所）；Lennard-Jones Laboratories, Keele University（基尔大学伦纳德-琼斯实验室）
深星系调查显示，宇宙中的全球恒星形成率（SFR）密度在1 < z < 2时达到峰值，并在z = 0时急剧下降。但是，一个清晰的基本过程，特别是冷原子（~100 K）和分子气相的演变，驱动这样一个强大的演变尚未出现。MALS的设计目的是使用MeerKAT的L波段和UHF波段接收器，对0 < z < 2处的HI 21-cm和OH 18-cm吸收线进行最灵敏的（N（HI）>10 $^{19}$ cm $^{-2}$）尘埃无偏搜索。这将为星系冷原子和分子气体截面的演化提供可靠的测量，并揭示驱动SFR密度急剧演化的过程。从调查中获得的HI和OH吸收剂的大样本将（i）导致物理学的基本常数的最严格的约束，和（ii）是理想的适合于通过塞曼分裂或旋转测量合成探测星系盘中的磁场的演变。该调查还将提供HI和OH吸收剂的无偏普查，即在0 < z < 2时与强大AGN（>10 $^{24}$ W Hz $^{-1}$）相关的冷气体，并将同时提供盲HI和OH发射线调查和无线电连续谱调查。在这里，我们描述的MALS调查设计，观测计划和科学问题下，要解决的各种科学主题。
A MeerKAT view of the Neutral Atomic Gas in Stephan's Quintet
Naval Research Laboratory（海军研究实验室）；Caltech/IPAC（加州理工学院/IPAC）；Chinese Academy of Sciences South America Center for astronomy, National Astronomical Observatories, CAS（中国科学院南美天文中心，国家天文台，中科院）；National astronomical Observatories（国家天文台）
MIGHTEE: The evolving radio luminosity functions of star-forming galaxies to $z\sim 4.5$ and the cosmic history of star formation
University of Oxford（牛津大学）；UKRI STFC Rutherford Appleton Laboratory（英国研究与创新部STFC拉瑟福德阿普尔顿实验室）；University of the Western Cape（西开普大学）；Institute for Astronomy, University of Edinburgh（爱丁堡大学天文研究所）；Carnegie Observatories（卡内基观测站）；Rhodes University（罗德兹大学）
