B. M. Pazderska, M. P. Gawronski, R. Feiler, M. Birkinshaw, I. W. A. Browne, R. Davis, A. J. Kus, K. Lancaster, S. R. Lowe, E. Pazderski, M. Peel, P. N. Wilkinson
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10 pages, 7 Postscript figures, to be published in A&A
We report the results of a survey of 442 planetary nebulae at 30 GHz. The purpose of the survey is to develop a list of planetary nebulae as calibration sources which could be used for high frequency calibration in future. For 41 PNe with sufficient data, we test the emission mechanisms in order to evaluate whether or not spinning dust plays an important role in their spectra at 30 GHz.
The 30-GHz data were obtained with a twin-beam differencing radiometer, OCRA-p, which is in operation on the Torun 32-m telescope. Sources were scanned both in right ascension and declination. We estimated flux densities at 30 GHz using a free-free emission model and compared it with our data.
The primary result is a catalogue containing the flux densities of 93 planetary nebulae at 30 GHz. Sources with sufficient data were compared with a spectral model of free-free emission. The model shows that free-free emission can generally explain the observed flux densities at 30 GHz thus no other emission mechanism is needed to account for the high frequency spectra.
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)
Early Science with the Large Millimetre Telescope: Molecules in the Extreme Outflow of a proto-Planetary Nebula
极高速度的发射可能与喷流有关,已知在一些原行星状星云中发生。然而,这种运动学成分的分子复杂性在很大程度上是未知的。我们观察到已知的极端流出的原行星状星云IRAS 16342-3814,一个原型喷泉,在全频率范围从73至111 GHz的RSR接收器的大毫米望远镜。我们检测到的分子SiO,HCN,SO,和$^{13}$ CO。所有的分子跃迁,除了后者是第一次在这个源中检测到,和所有目前的排放速度高达几百公里秒$^{-1}$。因此,IRAS 16342-3814是唯一一个同时在所有这些分子中表现出极端外流活动的源,SO和SiO的发射显示了这些物质在原行星状星云中的最高速度。待确认的是一个半高宽$\sim$为700 km s $^{-1}$的暂定弱SO分量。极端流出气体由稠密气体(n $_{\rm H_2} >$ 10 $^{4.8}$ --10 $^{5.7}$ cm $^{-3}$)组成,其质量大于$\sim$ 0.02--0.15 M $_{\odot}$。相对高丰度的SiO和SO可能是富氧极高速气体的指示。
SCORPIO-II: Spectral indices of weak Galactic radio sources
在未来几年内,对大型巡天观测到的射电源进行分类将是一个具有挑战性的问题,而谱指数是解决这一问题的有力工具,本文提出了一种从多波长射电图像中估计射电源谱指数的算法。我们已经将我们的算法应用于SCORPIO(Umana et al. 2015),这是一项以ATCA为中心的2.1 GHz银河平面调查,发现我们只能测量比均方根噪声强40倍的源的可靠光谱指数。超过1 mJy的阈值,天蝎座的源密度比典型的河外场(如ATLAS)大20%(Norris et al. 2006),这是因为银河系源的存在。在这个过剩的人口中,每平方度有16个源的光谱指数约为零,这表明光学薄的热发射,如Hii区域和行星状星云,而每平方度有12个源的光谱呈上升趋势,这表明光学厚的热发射,如恒星和UCHii区域。
The 10-15 GHz radio continuum survey of the Galactic Plane with SKAO
West Virginia University(西弗吉尼亚大学);University of Geneva(日内瓦大学);Korea Astronomy and Space Science Institute (KASI)(韩国天体宇宙科学研究所);Tata Institute of Fundamental Research(塔塔基础研究所);Royal Observatory Edinburgh(爱丁堡皇家天文台);National Astronomical Observatory of Japan(日本国立天文台);Indian Institute of Space Science and Technology (IIST)(印度空间科学与技术学院);Université Paris-Saclay(巴黎萨克雷大学);University of Leeds(利兹大学);University of Manchester(曼彻斯特大学);University of Kent(肯特大学);Univ. Bordeaux(波尔多大学);Univ. Grenoble Alpes(格勒诺布尔阿尔卑斯大学);Max Planck Institute for Astronomy(马克斯·普朗克天文学研究所);Aix Marseille Univ(艾克斯-马赛大学);Sorbonne Université(索邦大学);Observatoire de Paris(巴黎天文台);University of Central Florida(中佛罗里达大学);University of Puerto Rico(波多黎各大学);Nicolaus Copernicus University in Toruń(托伦哥白尼大学);Chinese Academy of Sciences(中国科学院);Rhodes University(罗德斯大学);University of Vienna(维也纳大学);Chalmers University of Technology(查尔姆斯理工大学);Peking University(北京大学)
A global view on star formation: The GLOSTAR Galactic plane survey. VI. Radio Source Catalog II: $28^\circ < \ell < 36^\circ$ and $|b| < 1^\circ$, VLA B-configuration