scholarly journals Three-dimensional magnetic field structure of six parsec-scale active galactic nuclei jets

2009 ◽  
Vol 393 (2) ◽  
pp. 429-456 ◽  
Author(s):  
S. P. O'Sullivan ◽  
D. C. Gabuzda
Keyword(s):  
Magnetic Field ◽  
Active Galactic Nuclei ◽  
Three Dimensional ◽  
Galactic Nuclei ◽  
Field Structure ◽  
Magnetic Field Structure ◽  
Active Galactic Nuclei Jets

scholarly journals Optical polarization properties of AGNs with significant VLBI–Gaia offsets

2020 ◽  
Vol 493 (1) ◽  
pp. L54-L58 ◽  
Author(s):  
Y Y Kovalev ◽  
D I Zobnina ◽  
A V Plavin ◽  
D Blinov
Keyword(s):  
Magnetic Field ◽  
Active Galactic Nuclei ◽  
Observational Data ◽  
Galactic Nuclei ◽  
Field Structure ◽  
Toroidal Magnetic Field ◽  
Accretion Discs ◽  
Optical Polarization ◽  
Polarization Direction ◽  
Magnetic Field Structure

ABSTRACT Significant positional offsets of the value from 1 mas to more than 10 mas were found previously between radio (VLBI) and optical (Gaia) positions of active galactic nuclei (AGNs). They happen preferentially parallel to the parsec-scale jet direction. AGNs with VLBI-to-Gaia offsets pointed downstream the jet are found to have favourably higher optical polarization, as expected if extended optical jets dominate in the emission and shift the Gaia centroid away from the physical nucleus of the source. Upstream offsets with the suggested domination of accretion discs manifest themselves through the observed low optical polarization. Direction of linear optical polarization is confirmed to preferentially align with parsec-scale jets in AGNs with dominant jets consistent with a toroidal magnetic field structure. Our findings support the disc–jet interpretation of the observed positional offsets. These results call on an intensification of AGN optical polarization monitoring programs in order to collect precious observational data. Taken together with the continued VLBI and Gaia observations, they will allow researchers to reconstruct detailed models of the disc–jet system in AGNs on parsec scales.

scholarly journals Magnetic inhibition of the recollimation instability in relativistic jets

2021 ◽  
Vol 503 (4) ◽  
pp. 4918-4929
Author(s):  
Jin Matsumoto ◽  
Serguei S Komissarov ◽  
Konstantinos N Gourgouliatos
Keyword(s):  
Magnetic Field ◽  
Active Galactic Nuclei ◽  
Three Dimensional ◽  
Galactic Nuclei ◽  
Rotating Fluids ◽  
Relativistic Jets ◽  
Azimuthal Magnetic Field ◽  
Centrifugal Instability ◽  
Magnetohydrodynamic Simulations

ABSTRACT In this paper, we describe the results of three-dimensional relativistic magnetohydrodynamic simulations aimed at probing the role of regular magnetic field on the development of the instability that accompanies recollimation of relativistic jets. In particular, we studied the recollimation driven by the reconfinement of jets from active galactic nuclei (AGN) by the thermal pressure of galactic coronas. We find that a relatively weak azimuthal magnetic field can completely suppress the recollimation instability in such jets, with the critical magnetization parameter σcr < 0.01. We argue that the recollimation instability is a variant of the centrifugal instability (CFI) and show that our results are consistent with the predictions based on the study of magnetic CFI in rotating fluids. The results are discussed in the context of AGN jets in general and the nature of the Fanaroff–Riley morphological division of extragalactic radio sources in particular.

scholarly journals The Detailed Magnetic Field Structure in the SW Quadrant of M31

1990 ◽  
Vol 140 ◽  
pp. 198-200
Author(s):  
R. Beck ◽  
E.M. Berkhuijsen
Keyword(s):  
Magnetic Field ◽  
Coming Out ◽  
Three Dimensional ◽  
Field Structure ◽  
Magnetic Field Structure ◽  
External Galaxy ◽  
Jeans Instability ◽  
The Magnetic Field

A three-dimensional, arc-like structure in the magnetic field was found coming out of the plane of M31. This structure may be the first Parker-Jeans instability observed in an external galaxy.

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