TY - JOUR

T1 - Polarization of active galactic nuclei with significant VLBI- Gaia displacements

AU - Blinov, D.

AU - Arshinova, A.

N1 - Export Date: 18 November 2024 CODEN: AAEJA Сведения о финансировании: Junta de Andalucía Сведения о финансировании: Instituto de Astrofísica de Andalucía, IAA Сведения о финансировании: Ministry of Education and Science of the Russian Federation, Minobrnauka Сведения о финансировании: Consejo Superior de Investigaciones Científicas, CSIC Сведения о финансировании: European Research Council, ERC Сведения о финансировании: 101040021 Текст о финансировании 1: D.B. acknowledges support from the European Research Council (ERC) under the Horizon ERC Grants 2021 programme under the grant agreement No. 101040021. The work of A.A. was performed as part of the SAO RAS government contract approved by the Ministry of Science and Higher Education of the Russian Federation. Based on observations collected at the Centro Astron\u00F3mico Hisp\u00E1nico en Andaluc\u00EDa (CAHA), operated jointly by the Instituto de Astrofisica de Andalucia (CSIC) and the Andalusian Universities (Junta de Andaluc\u00EDa).

PY - 2024/10/29

Y1 - 2024/10/29

N2 - Context. Numerous studies have reported significant displacements in the coordinates of active galactic nuclei (AGNs) between measurements using the very-long-baseline-interferometry (VLBI) technique and those obtained by the Gaia space observatory. There is consensus that these discrepancies do indeed manifest astrometrically resolved sub-components of AGNs rather than random measurement noise. Among other evidence, it has been reported that AGNs with VLBI-to-Gaia displacements (VGDs) pointing downstream of their parsec-scale radio jets exhibit higher optical polarization compared to sources with the opposite (upstream) VGD orientation. Aims. We aim to verify the previously reported connection between optical polarization and a VGD-jet angle using a larger dataset of polarimetric measurements and updated Gaia DR3 positions. We also seek further evidence supporting the disk-jet dichotomy as an explanation of such a connection by using millimeter-wave polarization and multiband optical polarization measurements. Methods. We performed optical polarimetric observations of 152 AGNs using three telescopes. These data are complemented by other publicly available polarimetric measurements of AGNs. We cross-matched public astrometric data from VLBI and Gaia experiments, obtained corresponding positional displacements, and combined this catalog with the polarimetric and jet direction data. Results. Active galactic nuclei with downstream VGDs are confirmed to have significantly higher optical fractional polarization than the upstream sample. At the same time, the millimeter-wavelength polarization of the two samples shows very similar distributions. Conclusions. Our results support the hypothesis that the VGDs pointing down the radio jet are likely caused by a component in the jet emitting highly polarized synchrotron radiation and dominating in the overall optical emission. The upstream-oriented VGDs are likely to be produced by the low-polarization emission of the central engine's subcomponents, which dominate in the optical. © The Authors 2024.

AB - Context. Numerous studies have reported significant displacements in the coordinates of active galactic nuclei (AGNs) between measurements using the very-long-baseline-interferometry (VLBI) technique and those obtained by the Gaia space observatory. There is consensus that these discrepancies do indeed manifest astrometrically resolved sub-components of AGNs rather than random measurement noise. Among other evidence, it has been reported that AGNs with VLBI-to-Gaia displacements (VGDs) pointing downstream of their parsec-scale radio jets exhibit higher optical polarization compared to sources with the opposite (upstream) VGD orientation. Aims. We aim to verify the previously reported connection between optical polarization and a VGD-jet angle using a larger dataset of polarimetric measurements and updated Gaia DR3 positions. We also seek further evidence supporting the disk-jet dichotomy as an explanation of such a connection by using millimeter-wave polarization and multiband optical polarization measurements. Methods. We performed optical polarimetric observations of 152 AGNs using three telescopes. These data are complemented by other publicly available polarimetric measurements of AGNs. We cross-matched public astrometric data from VLBI and Gaia experiments, obtained corresponding positional displacements, and combined this catalog with the polarimetric and jet direction data. Results. Active galactic nuclei with downstream VGDs are confirmed to have significantly higher optical fractional polarization than the upstream sample. At the same time, the millimeter-wavelength polarization of the two samples shows very similar distributions. Conclusions. Our results support the hypothesis that the VGDs pointing down the radio jet are likely caused by a component in the jet emitting highly polarized synchrotron radiation and dominating in the overall optical emission. The upstream-oriented VGDs are likely to be produced by the low-polarization emission of the central engine's subcomponents, which dominate in the optical. © The Authors 2024.

KW - Astrometry

KW - Polarization

KW - Quasars: general

KW - Techniques: interferometric

KW - Active Galactic Nuclei

KW - Displacement measurement

KW - Electromagnetic pulse

KW - Ellipsometry

KW - Interferometers

KW - Interferometry

KW - Light polarization

KW - Luminescence of liquids and solutions

KW - Polarimeters

KW - Synchrotron radiation

KW - White dwarfs

KW - Active galactic nuclei

KW - Down-stream

KW - Interferometry technique

KW - Optical-

KW - Polarimetric measurements

KW - Quasars:general

KW - Radio jet

KW - Technique: interferometric

KW - Very long baseline interferometry

KW - Millimeter waves

UR - https://www.mendeley.com/catalogue/a4b6990c-e265-3dd1-b376-1db15fcfcca6/

U2 - 10.1051/0004-6361/202451186

DO - 10.1051/0004-6361/202451186

M3 - статья

VL - 691

JO - ASTRONOMY & ASTROPHYSICS

JF - ASTRONOMY & ASTROPHYSICS

SN - 0004-6361

ER -