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arXiv 2004.00346astro-ph.IM
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用单碟radio telescopes探测和分析弱射电源的方法

Methods for detection and analysis of weak radio sources with single-dish radio telescopes

M. Marongiu, A. Pellizzoni, E. Egron, T. Laskar, M. Giroletti, S. Loru, A. Melis, G. Carboni, C. Guidorzi, S. Kobayashi, N. Jordana-Mitjans, A. Rossi, C. G. Mun… 展开作者

M. Marongiu, A. Pellizzoni, E. Egron, T. Laskar, M. Giroletti, S. Loru, A. Melis, G. Carboni, C. Guidorzi, S. Kobayashi, N. Jordana-Mitjans, A. Rossi, C. G. Mundell, R. Concu, R. Martone, L. Nicastro

摘要:

mJy/sub-mJy点源的探测是单碟射电望远镜的一个重大挑战。伽玛暴或宇宙学距离上其他源的微弱余辉的检测或上限是约束源建模的重要手段。使用撒丁岛射电望远镜(SRT),我们比较了三种方法的灵敏度和鲁棒性适用于检测微弱的无线电源从光栅地图周围的一个已知的源位置:智能快速查找方法,源提取方法(典型的高能天文学),并与2-D高斯拟合。我们开发了一个Python代码,专门用于分析点状射电源,应用于SRT C波段(6.9 GHz)观测未检测到的源(181201 A和190114 C的GRB余辉)和检测到的银河X射线双星GRS 1915+105。我们对不同检测方法的比较分析广泛使用模拟作为对实际无线电观测的有益补充。SRT数据分析的最佳方法是使用二维高斯拟合,因为它将单碟观测的灵敏度限制-相对于更传统的技术-降低到~ 1.8 mJy,与初始值相比提高了~ 40%。这一分析表明,特别是对于微弱的源,爆发前或爆发后扫描区域的良好地图至关重要。

英文摘要:

The detection of mJy/sub-mJy point sources is a significant challenge for single-dish radio telescopes. Detection or upper limits on the faint afterglow from GRBs or other sources at cosmological distances are important means of constraining the source modeling. Using the Sardinia Radio Telescope (SRT), we compare the sensitivity and robustness of three methods applied to the detection of faint radio sources from raster maps around a known source position: the smart quick-look method, the source extraction method (typical of high-energy astronomy), and the fit with a 2-D Gaussian. We developed a Python code specific for the analysis of point-like radio sources applied to the SRT C-band (6.9 GHz) observations of both undetected sources (GRB afterglows of 181201A and 190114C) and the detected Galactic X-ray binary GRS 1915+105. Our comparative analysis of the different detection methods made extensive use of simulations as a useful complement to actual radio observations. The best method for the SRT data analysis is the fit with a 2-D Gaussian, as it pushes down the sensitivity limits of single-dish observations -- with respect to more traditional techniques -- to ~ 1.8 mJy, improving by ~ 40 % compared with the initial value. This analysis shows that -- especially for faint sources -- good maps of the scanned region pre- or post-outburst are essential.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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