Revisiting 3C 279 jet morphology with space VLBI at 26 microarcsecond resolution

We present observations of the blazar 3C 279 at 22 GHz by the space-based very long baseline interferometry mission RadioAstron from January 15, 2018. We reconstructed images in both total intensity and fractional polarization using the regularized maximum likelihood method implemented in the eht-imaging library. The electric vector position angles are found to be mostly aligned with the general jet direction, suggesting a predominantly toroidal magnetic field and in agreement with the presence of a helical magnetic field. Ground-space fringes were detected up to a projected baseline length of ∼8 G λ , achieving an angular resolution of around 26 μas. The fine-scale structure of the relativistic jet is found in our study to extend to a projected distance of ∼180 parsec from the radio core. However, the filamentary structure reported by previous RadioAstron observations from 2014 is not detected in our current study. We discuss potential causes for this phenomenon and present a comparison using public 43 GHz data from the BEAM-ME program showing a significant drop in the jet’s total intensity. We observe that the optically thick core has a brightness temperature of 1.6 × 10 12 K, consistent with equipartition between the energy densities of the relativistic particles and the magnetic field. This yields an estimated magnetic field strength of 0.2 G.

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Publication Details

Journal
Astronomy and Astrophysics
Published
2025-11-10
DOI
https://doi.org/10.1051/0004-6361/202555188
Citations
1
Primary Topic
Astrophysics and Cosmic Phenomena
Type
article
Field-Weighted Citation Impact
1.87
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article

Revisiting 3C 279 jet morphology with space VLBI at 26 microarcsecond resolution

Teresa Toscano, T. Savolainen, A. B. Pushkarev, Y. Y. Kovalev et al.
1 citations
Astronomy and Astrophysics
Astrophysics and Cosmic Phenomena
1.87
article

Revisiting 3C 279 jet morphology with space VLBI at 26 microarcsecond resolution

Teresa Toscano, T. Savolainen, A. B. Pushkarev, Y. Y. Kovalev, Efthalia Traianou, Guang-Yao Zhao, Felix M. Pötzl, Maciek Wielgus, Antonio Fuentes, Mikhail Lisakov, José L. Gómez, Ai-Ling Zeng, Jan Röder, Rocco Lico, I. Leonid Gurvits
article en
1 citations

Abstract

We present observations of the blazar 3C 279 at 22 GHz by the space-based very long baseline interferometry mission RadioAstron from January 15, 2018. We reconstructed images in both total intensity and fractional polarization using the regularized maximum likelihood method implemented in the eht-imaging library. The electric vector position angles are found to be mostly aligned with the general jet direction, suggesting a predominantly toroidal magnetic field and in agreement with the presence of a helical magnetic field. Ground-space fringes were detected up to a projected baseline length of ∼8 G λ , achieving an angular resolution of around 26 μas. The fine-scale structure of the relativistic jet is found in our study to extend to a projected distance of ∼180 parsec from the radio core. However, the filamentary structure reported by previous RadioAstron observations from 2014 is not detected in our current study. We discuss potential causes for this phenomenon and present a comparison using public 43 GHz data from the BEAM-ME program showing a significant drop in the jet’s total intensity. We observe that the optically thick core has a brightness temperature of 1.6 × 10 12 K, consistent with equipartition between the energy densities of the relativistic particles and the magnetic field. This yields an estimated magnetic field strength of 0.2 G.

Astronomy and AstrophysicsVol. 704
Pontificia Universidad Católica de Valparaíso (CL), Heidelberg University (DE), Shanghai Astronomical Observatory (CN), Astro Space Center (RU), Istituto di Radioastronomia di Bologna (IT), Forschungsstätte der Evangelischen Studiengemeinschaft (DE), Institute of Theoretical Physics (CN), Computational Physics (United States) (US), Max Planck Institute for Radio Astronomy (DE), Instituto de Astrofísica de Andalucía (ES), Crimean Astrophysical Observatory (UA), Joint Institute for VLBI ERIC (NL), Foundation for Research and Technology Hellas (GR), Delft University of Technology (NL), Aalto University (FI)
Openalex Percentile: Top 11%
Astrophysics and Cosmic Phenomena
1.87
DOIOpen Access PDFOpenAlex
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