Intra-night optical polarization monitoring of blazars
Journal article, 2025
Blazars are known for their extreme variability across the electromagnetic spectrum. Variability at very short timescales can allow us to discriminate between competing models. This is particularly true for polarization variability, which allows us to probe particle acceleration and high-energy emission models in blazars. Here we present results from the first pilot study of intra-night optical polarization monitoring conducted using RoboPol at the Skinakas Observatory; these results are supplemented by observations from the Calar Alto, Perkins, and Sierra Nevada observatories. Our results show that while variability patterns can vary widely between sources, variability on timescales as short as minutes is prevalent in blazar jets. The amplitudes of the variations are typically small, a few percent for the polarization degree and less than 20° for the polarization angle, pointing to a significant contribution to the optical emission from a turbulent magnetic field component. The overall stability of the polarization angle over time points to a preferred magnetic field orientation.
relativistic processes
BL Lacertae objects: general
galaxies: active
galaxies: jets
polarization
Author
Aristeidis Polychronakis
Foundation for Research and Technology Hellas (FORTH)
University of Crete
I. Liodakis
Foundation for Research and Technology Hellas (FORTH)
Anastasia Glykopoulou
University of Crete
Foundation for Research and Technology Hellas (FORTH)
D. Blinov
University of Crete
Foundation for Research and Technology Hellas (FORTH)
I. Agudo
Spanish National Research Council (CSIC)
S.G. Jorstad
Saint Petersburg State University - Spsu
Boston University
Beatriz Agís-González
Foundation for Research and Technology Hellas (FORTH)
Sara Capecchiacci
Foundation for Research and Technology Hellas (FORTH)
University of Crete
Alberto Floris
Foundation for Research and Technology Hellas (FORTH)
University of Crete
Sebastian Kielhmann
Foundation for Research and Technology Hellas (FORTH)
J. A. Kypriotakis
University of Crete
Foundation for Research and Technology Hellas (FORTH)
Dimitrios A. Langis
University of Crete
Foundation for Research and Technology Hellas (FORTH)
N. Mandarakas
Laboratoire d'Astrophysique de Marseille
Foundation for Research and Technology Hellas (FORTH)
University of Crete
Karan Pal
University of Erlangen-Nuremberg (FAU)
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Francisco J. Aceituno
Spanish National Research Council (CSIC)
G. Bonnoli
Istituto nazionale di astrofisica (INAF)
Spanish National Research Council (CSIC)
Víctor Casanova
Spanish National Research Council (CSIC)
G. Emery
Spanish National Research Council (CSIC)
Juan Escudero Pedrosa
Harvard-Smithsonian Center for Astrophysics
Spanish National Research Council (CSIC)
J. Otero-Santos
National Institute for Nuclear Physics
Spanish National Research Council (CSIC)
D. Morcuende
Spanish National Research Council (CSIC)
Alfredo Sota
Spanish National Research Council (CSIC)
Vilppu Piirola
University of Turku
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 704 A311Subject Categories (SSIF 2025)
Astronomy, Astrophysics, and Cosmology
DOI
10.1051/0004-6361/202557558