Intra-Day Variability Observations of Two Dozens of Blazars at 4.8 GHz
Two dozens of radio loud active galactic nuclei (AGNs) have been observed with Urumqi 25 m radio telescope in order to search for intra-day variability (IDV). The target sources are blazars (namely flat spectrum radio quasars and BL Lac objects) which are mostly selected from the observing list of R...
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MDPI AG
2021-01-01
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| Series: | Universe |
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| Online Access: | https://www.mdpi.com/2218-1997/7/1/15 |
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| author | Xiang Liu Xin Wang Ning Chang Jun Liu Lang Cui Xiaofeng Yang Thomas P. Krichbaum |
| author_facet | Xiang Liu Xin Wang Ning Chang Jun Liu Lang Cui Xiaofeng Yang Thomas P. Krichbaum |
| author_sort | Xiang Liu |
| collection | DOAJ |
| description | Two dozens of radio loud active galactic nuclei (AGNs) have been observed with Urumqi 25 m radio telescope in order to search for intra-day variability (IDV). The target sources are blazars (namely flat spectrum radio quasars and BL Lac objects) which are mostly selected from the observing list of RadioAstron AGN monitoring campaigns. The observations were carried out at 4.8 GHz in two sessions of 8–12 February 2014 and 7–9 March respectively. We report the data reduction and the first results of observations. The results show that the majority of the blazars exhibit IDV in 99.9% confidence level, some of them show quite strong IDV. We find the strong IDV of blazar 1357 + 769 for the first time. The IDV at centimeter-wavelength is believed to be predominately caused by the scintillation of blazar emission through the local interstellar medium in a few hundreds parsecs away from Sun. No significant correlation between the IDV strength and either redshift or Galactic latitude is found in our sample. The IDV timescale along with source structure and brightness temperature analysis will be presented in a forthcoming paper. |
| first_indexed | 2024-03-09T04:52:14Z |
| format | Article |
| id | doaj.art-aef57a545e0e4a29952caf871da877e3 |
| institution | Directory Open Access Journal |
| issn | 2218-1997 |
| language | English |
| last_indexed | 2024-03-09T04:52:14Z |
| publishDate | 2021-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Universe |
| spelling | doaj.art-aef57a545e0e4a29952caf871da877e32023-12-03T13:09:59ZengMDPI AGUniverse2218-19972021-01-01711510.3390/universe7010015Intra-Day Variability Observations of Two Dozens of Blazars at 4.8 GHzXiang Liu0Xin Wang1Ning Chang2Jun Liu3Lang Cui4Xiaofeng Yang5Thomas P. Krichbaum6Xinjiang Astronomical Observatory, Chinese Academy of Sciences, 150 Science 1-Street, Urumqi 830011, ChinaXinjiang Astronomical Observatory, Chinese Academy of Sciences, 150 Science 1-Street, Urumqi 830011, ChinaXinjiang Astronomical Observatory, Chinese Academy of Sciences, 150 Science 1-Street, Urumqi 830011, ChinaMax-Plank-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, GermanyXinjiang Astronomical Observatory, Chinese Academy of Sciences, 150 Science 1-Street, Urumqi 830011, ChinaXinjiang Astronomical Observatory, Chinese Academy of Sciences, 150 Science 1-Street, Urumqi 830011, ChinaMax-Plank-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, GermanyTwo dozens of radio loud active galactic nuclei (AGNs) have been observed with Urumqi 25 m radio telescope in order to search for intra-day variability (IDV). The target sources are blazars (namely flat spectrum radio quasars and BL Lac objects) which are mostly selected from the observing list of RadioAstron AGN monitoring campaigns. The observations were carried out at 4.8 GHz in two sessions of 8–12 February 2014 and 7–9 March respectively. We report the data reduction and the first results of observations. The results show that the majority of the blazars exhibit IDV in 99.9% confidence level, some of them show quite strong IDV. We find the strong IDV of blazar 1357 + 769 for the first time. The IDV at centimeter-wavelength is believed to be predominately caused by the scintillation of blazar emission through the local interstellar medium in a few hundreds parsecs away from Sun. No significant correlation between the IDV strength and either redshift or Galactic latitude is found in our sample. The IDV timescale along with source structure and brightness temperature analysis will be presented in a forthcoming paper.https://www.mdpi.com/2218-1997/7/1/15quasars: generalgalaxies: jetsradio continuum:galaxiesISM: structurescattering |
| spellingShingle | Xiang Liu Xin Wang Ning Chang Jun Liu Lang Cui Xiaofeng Yang Thomas P. Krichbaum Intra-Day Variability Observations of Two Dozens of Blazars at 4.8 GHz Universe quasars: general galaxies: jets radio continuum:galaxies ISM: structure scattering |
| title | Intra-Day Variability Observations of Two Dozens of Blazars at 4.8 GHz |
| title_full | Intra-Day Variability Observations of Two Dozens of Blazars at 4.8 GHz |
| title_fullStr | Intra-Day Variability Observations of Two Dozens of Blazars at 4.8 GHz |
| title_full_unstemmed | Intra-Day Variability Observations of Two Dozens of Blazars at 4.8 GHz |
| title_short | Intra-Day Variability Observations of Two Dozens of Blazars at 4.8 GHz |
| title_sort | intra day variability observations of two dozens of blazars at 4 8 ghz |
| topic | quasars: general galaxies: jets radio continuum:galaxies ISM: structure scattering |
| url | https://www.mdpi.com/2218-1997/7/1/15 |
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