Hubble Space Telescopeand Ground‐based Observations of I Zw 1 and MRK 486 and the Variability of Polarization in Radio‐quiet Active Galactic Nuclei

1997 ◽  
Vol 488 (1) ◽  
pp. 202-215 ◽  
Author(s):  
Paul S. Smith ◽  
Gary D. Schmidt ◽  
Richard G. Allen ◽  
Dean C. Hines
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei

INVESTIGATION OF INTRADAY VARIABILITY OF ACTIVE GALACTIC NUCLEI IN OPTICAL AND RADIO RANGES

2010 ◽  
Vol 1 (2) ◽  
pp. 111-115
Author(s):  
O. E. Volvach ◽  
L. N. Volvach ◽  
V. S. Bichkova ◽  
M. S. Kardashev ◽  
M. G. Larionov ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Intraday Variability

Polarization Variability of Active Galactic Nuclei and X‐Ray Binaries

1997 ◽  
Vol 487 (1) ◽  
pp. 142-152 ◽  
Author(s):  
Gang Bao ◽  
Petr Hadrava ◽  
Paul J. Wiita ◽  
Ying Xiong
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
X Ray ◽  
X Ray Binaries

Statistics of Active Galactic Nuclei in Rich Clusters Revisited

1998 ◽  
Vol 502 (1) ◽  
pp. 134-140 ◽  
Author(s):  
M. J. Way ◽  
R. A. Flores ◽  
H. Quintana
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei

scholarly journals Polarimetric Properties of Blazars Caught by the WEBT

Galaxies ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 42
Author(s):  
Claudia M. Raiteri ◽  
Massimo Villata
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Plasma Jets ◽  
Line Of Sight ◽  
Optical Behaviour ◽  
Relativistic Jets ◽  
Comprehensive Picture ◽  
Multi Wavelength ◽  
Extreme Variability ◽  
Continuous Range

Active galactic nuclei come in many varieties. A minority of them are radio-loud, and exhibit two opposite prominent plasma jets extending from the proximity of the supermassive black hole up to megaparsec distances. When one of the relativistic jets is oriented closely to the line of sight, its emission is Doppler beamed and these objects show extreme variability properties at all wavelengths. These are called “blazars”. The unpredictable blazar variability, occurring on a continuous range of time-scales, from minutes to years, is most effectively investigated in a multi-wavelength context. Ground-based and space observations together contribute to give us a comprehensive picture of the blazar emission properties from the radio to the γ-ray band. Moreover, in recent years, a lot of effort has been devoted to the observation and analysis of the blazar polarimetric radio and optical behaviour, showing strong variability of both the polarisation degree and angle. The Whole Earth Blazar Telescope (WEBT) Collaboration, involving many tens of astronomers all around the globe, has been monitoring several blazars since 1997. The results of the corresponding data analysis have contributed to the understanding of the blazar phenomenon, particularly stressing the viability of a geometrical interpretation of the blazar variability. We review here the most significant polarimetric results achieved in the WEBT studies.

scholarly journals RoboPol: AGN polarimetric monitoring data

2020 ◽  
Author(s):  
D Blinov ◽  
S Kiehlmann ◽  
V Pavlidou ◽  
G V Panopoulou ◽  
R Skalidis ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Average Degree ◽  
Monitoring Data ◽  
Degree Of Polarization ◽  
Time Interval ◽  
Current Version ◽  
Variability Index ◽  
Entire Dataset

Abstract We present uniformly reprocessed and re-calibrated data from the RoboPol programme of optopolarimetric monitoring of active galactic nuclei (AGN), covering observations between 2013, when the instrument was commissioned, and 2017. In total, the dataset presented in this paper includes 5068 observations of 222 AGN with Dec > −25○. We describe the current version of the RoboPol pipeline that was used to process and calibrate the entire dataset, and we make the data publicly available for use by the astronomical community. Average quantities summarising optopolarimetric behaviour (average degree of polarization, polarization variability index) are also provided for each source we have observed and for the time interval we have followed it.

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