X-ray polarization of the high-synchrotron-peak BL Lacertae object 1ES 1959+650 during intermediate and high X-ray flux states

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F25%3A00619607" target="_blank" >RIV/67985815:_____/25:00619607 - isvavai.cz</a>

Result on the web

<a href="https://hdl.handle.net/11104/0366272" target="_blank" >https://hdl.handle.net/11104/0366272</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3847/1538-4357/adbbe2" target="_blank" >10.3847/1538-4357/adbbe2</a>

Result language

angličtina

Original language name

X-ray polarization of the high-synchrotron-peak BL Lacertae object 1ES 1959+650 during intermediate and high X-ray flux states

Original language description

We report the Imaging X-ray Polarimetry Explorer (IXPE) polarimetric and simultaneous multiwavelength observations of the high-energy-peaked BL Lacertae object (HBL) 1ES 1959+650, performed in 2022 October and 2023 August. In 2022 October, IXPE measured an average polarization degree Pi X = 9.4% +/- 1.6% and an electric-vector position angle psi X = 53 degrees +/- 5 degrees. The polarized X-ray emission can be decomposed into a constant component, plus a rotating component, with the rotation velocity omega EVPA = (-117 +/- 12) deg day-1. In 2023 August, during a period of pronounced activity of the source, IXPE measured an average Pi X = 12.4% +/- 0.7% and psi X = 20 degrees +/- 2 degrees, with evidence (similar to 0.4% chance probability) for a rapidly rotating component with omega EVPA = 1864 +/- 34 deg day-1. These findings suggest the presence of a helical magnetic field in the jet of 1ES 1959+650 or stochastic processes governing the field in turbulent plasma. Our multiwavelength campaigns from radio to X-ray reveal variability in both polarization and flux from optical to X-rays. We interpret the results in terms of a relatively slowly varying component dominating the radio and optical emission, while rapidly variable polarized components dominate the X-ray and provide minor contribution at optical wavelengths. The radio and optical data indicate that on parsec scales the magnetic field is primarily orthogonal to the jet direction. On the contrary, X-ray measurements show a magnetic field almost aligned with the parsec jet direction. Confronting with other IXPE observations, we guess that the magnetic field of HBLs on subparsec scale should be rather unstable, often changing its direction with respect to the Very Long Baseline Array jet.

Czech name

—

Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10308 - Astronomy (including astrophysics,space science)

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2025

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Astrophysical Journal

ISSN

0004-637X

e-ISSN

1538-4357

Volume of the periodical

983

Issue of the periodical within the volume

1

Country of publishing house

GB - UNITED KINGDOM

Number of pages

20

Pages from-to

78

UT code for WoS article

001461941800001

EID of the result in the Scopus database

2-s2.0-105003029882