Effelsberg Monitoring of a Sample of RadioAstron Blazars: Analysis of Intra-Day Variability
文献类型：期刊论文
| 作者 | Liu, Jun1,2,3 ; Bignall, Hayley4; Krichbaum, Thomas1; Liu, Xiang2,3; Kraus, Alex1; Kovalev, Yuri1,5,6; Sokolovsky, Kirill5,7,8; Angelakis, Emmanouil1; Zensus, J.1
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| 刊名 | Galaxies
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| 出版日期 | 2018-04-01 |
| 卷号 | 6期号:2页码:49 |
| 关键词 | galaxies active-method statistical-radio continuum ISM |
| ISSN号 | 2075-4434 |
| DOI | 10.3390/galaxies6020049 |
| 产权排序 | 2 |
| 英文摘要 | We present the first results of an ongoing intra-day variability (IDV) flux density monitoring program of 107 blazars, which were selected from a sample of RadioAstron space very long baseline interferometry (VLBI) targets. The~IDV observations were performed with the Effelsberg 100-m radio telescope at 4.8\,GHz, focusing on the statistical properties of IDV in a relatively large sample of compact active galactic nuclei (AGN). We investigated the dependence of rapid ($<$3 day) variability on various source properties through a likelihood approach. We found that the IDV amplitude depends on flux density and that fainter sources vary by about a factor of 3 more than their brighter counterparts. We also found a significant difference in the variability amplitude between inverted- and flat-spectrum radio sources, with the former exhibiting stronger variations. $\gamma$-ray loud sources were found to vary by up to a factor 4 more than $\gamma$-ray quiet ones, with 4$\sigma$ significance. However a galactic latitude dependence was barely observed, which suggests that it is predominantly the intrinsic properties (e.g., angular size, core-dominance) of the blazars that determine how they scintillate, rather than the directional dependence in the interstellar medium (ISM). We showed that the uncertainty in the VLBI brightness temperatures obtained from the space VLBI data of the RadioAstron satellite can be as high as $\sim$70\% due to the presence of the rapid flux density variations. Our statistical results support the view that IDV at centimeter wavelengths is predominantly caused by interstellar scintillation (ISS) of the emission from the most compact, core-dominant region in an AGN. |
| URL标识 | 查看原文 |
| 语种 | 英语 |
| 源URL | [http://ir.xao.ac.cn/handle/45760611-7/3216]  |
| 专题 | 星系宇宙学研究团组 新疆天文台_110米口径全可动射电望远镜（SmART）_110米大口径全可动射电望远镜关键技术研究（973项目）_课题1：大样本射电天体的观测和前沿问题研究 射电天文研究室_利用南山26米射电望远镜观测数据的文章 |
| 作者单位 | 1.Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn, Germany; 2.Xinjiang Astronomical Observatory, CAS, 150 Science 1-Street, Urumqi 830011, China; 3.Key Laboratory of Radio Astronomy, Chinese Academy of Sciences, Urumqi 830011, China; 4.CSIRO Astronomy and Space Science, P.O. Box 1130, Bentley, WA 6102, Australia; 5.Astro Space Center of Lebedev Physical Institute, Profsoyuznaya 84/32, 117997 Moscow, Russia; 6.Moscow Institute of Physics and Technology, Dolgoprudny, Institutsky per., 9, 141700 Moscow, Russia; 7.IAASARS, National Observatory of Athens, Vas. Pavlou & I. Metaxa, 15236 Penteli, Greece; 8.Sternberg Astronomical Institute, Moscow State University, Universitetskii pr. 13, 119992 Moscow, Russia |
| 推荐引用方式 GB/T 7714 | Liu, Jun,Bignall, Hayley,Krichbaum, Thomas,et al. Effelsberg Monitoring of a Sample of RadioAstron Blazars: Analysis of Intra-Day Variability[J]. Galaxies,2018,6(2):49. |
| APA | Liu, Jun.,Bignall, Hayley.,Krichbaum, Thomas.,Liu, Xiang.,Kraus, Alex.,...&Zensus, J..(2018).Effelsberg Monitoring of a Sample of RadioAstron Blazars: Analysis of Intra-Day Variability.Galaxies,6(2),49. |
| MLA | Liu, Jun,et al."Effelsberg Monitoring of a Sample of RadioAstron Blazars: Analysis of Intra-Day Variability".Galaxies 6.2(2018):49. |
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