RADIO SOURCES IN THE NCP REGION OBSERVED WITH THE 21 CENTIMETER ARRAY
文献类型：期刊论文
| 作者 | Zheng,Qian2,3,4; Wu,Xiang-Ping3,4,5; Johnston-Hollitt,Melanie2; Gu,Jun-hua3,4; Xu,Haiguang1 |
| 刊名 | The Astrophysical Journal
 |
| 出版日期 | 2016-11-30 |
| 卷号 | 832期号:2 |
| 关键词 | instrumentation: interferometers methods: observational radio continuum: galaxies radio continuum: general |
| ISSN号 | 0004-637X |
| DOI | 10.3847/0004-637X/832/2/190 |
| 英文摘要 | ABSTRACT We present a catalog of 624 radio sources detected around the North Celestial Pole (NCP) with the 21 Centimeter Array (21CMA), a radio interferometer dedicated to the statistical measurement of the epoch of reionization (EoR). The data are taken from a 12 hr observation made on 2013 April 13, with a frequency coverage from 75 to 175 MHz and an angular resolution of ～4′. The catalog includes flux densities at eight sub-bands across the 21CMA bandwidth and provides the in-band spectral indices for the detected sources. To reduce the complexity of interferometric imaging from the so-called “w” term and ionospheric effects, the present analysis is restricted to the east–west baselines within 1500 m only. The 624 radio sources are found within 5° around the NCP down to ～0.1 Jy. Our source counts are compared, and also exhibit a good agreement, with deep low-frequency observations made recently with the GMRT and MWA. In particular, for fainter radio sources below ～1 Jy, we find a flattening trend of source counts toward lower frequencies. While the thermal noise (～0.4 mJy) is well controlled to below the confusion limit, the dynamical range (～104)?and sensitivity of current 21CMA imaging are?largely limited by calibration and deconvolution errors, especially the grating lobes of very bright sources, such as 3C061.1, in the NCP field, which result from the regular spacings of the 21CMA. We note that particular attention should be paid to the extended sources, and their modeling and removal?may constitute a large technical challenge for current EoR experiments. Our analysis may serve as a useful guide to the design of next generation low-frequency interferometers like the Square Kilometre Array. |
| 语种 | 英语 |
| WOS记录号 | IOP:0004-637X-832-2-190 |
| 出版者 | The American Astronomical Society |
| 源URL | [http://119.78.226.72/handle/331011/32173]  |
| 专题 | 中国科学院上海天文台 |
| 作者单位 | 1.Department of Physics and Astronomy, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang, Shanghai, 200240, China 2.School of Chemical and Physical Sciences, P.O. Box 600, Victoria University of Wellington, Wellington 6140, New Zealand 3.National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Beijing 100012, China; wxp@bao.ac.cn 4.Center for Astronomical Mega-Science, Chinese Academy of Sciences, 20A Datun Road, Beijing 100012, China 5.Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai 200030, China |
| 推荐引用方式 GB/T 7714 | Zheng,Qian,Wu,Xiang-Ping,Johnston-Hollitt,Melanie,et al. RADIO SOURCES IN THE NCP REGION OBSERVED WITH THE 21 CENTIMETER ARRAY[J]. The Astrophysical Journal,2016,832(2). |
| APA | Zheng,Qian,Wu,Xiang-Ping,Johnston-Hollitt,Melanie,Gu,Jun-hua,&Xu,Haiguang.(2016).RADIO SOURCES IN THE NCP REGION OBSERVED WITH THE 21 CENTIMETER ARRAY.The Astrophysical Journal,832(2). |
| MLA | Zheng,Qian,et al."RADIO SOURCES IN THE NCP REGION OBSERVED WITH THE 21 CENTIMETER ARRAY".The Astrophysical Journal 832.2(2016). |
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