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We analysed the parsec-scale linear polarization properties of 436 active galactic nuclei (AGN) based on 15 GHz polarimetric Very Long Baseline Array (VLBA) observations. We present polarization and total intensity images averaged over at…

高能天体物理现象 · 物理学 2023-03-07 A. B. Pushkarev , M. F. Aller , H. D. Aller , D. C. Homan , Y. Y. Kovalev , M. L. Lister , I. N. Pashchenko , T. Savolainen , D. Zobnina

Blazars are relativistic magnetized plasma outflows from supermassive black holes that point very close to our line of sight. Their emission is nonthermal dominated and highly variable across the entire electromagnetic spectrum.…

高能天体物理现象 · 物理学 2020-10-14 Haocheng Zhang , Xiaocan Li , Dimitrios Giannios , Fan Guo , Yi-Hsin Liu , Lingyi Dong

An 11-day monitoring campaign in late 2005 reveals clear correlation in polarization between the optical emission and the region of the intensity peak (the "pseudocore") at the upstream end of the jet in 43 GHz Very Long Baseline Array…

We present a model of blazar variability that can both reproduce smooth large polarization angle swings, and at the same time allow for the seemingly random behaviour of synchrotron fluxes, polarization fraction and, occasionally, $\pi$/2…

高能天体物理现象 · 物理学 2017-03-22 Maxim Lyutikov , Evgeniya Kravchenko

Narrow line Seyfert 1 galaxies (NLSy1s) constitute the AGN subclass associated with systematically smaller black hole masses. A few radio loud ones have been detected in MeV -- GeV energy bands by Fermi and evidence for the presence of…

星系天体物理 · 物理学 2018-10-23 E. Angelakis , S. Kiehlmann , I. Myserlis , D. Blinov , J. Eggen , R. Itoh , N. Marchili , J. A. Zensus

We present an overview of new HST imaging polarimetry of six nearby radio galaxies with optical jets. These observations triple the number of extragalactic jets with subarcsecond-resolution optical polarimetry. We discuss the polarization…

Millimeter-band polarimetry offers a powerful probe of AGN jets, accessing regions less affected by opacity and Faraday rotation than at longer radio wavelengths. As part of the POLAMI program, we have conducted 14 years of 1 mm and 3 mm…

We discuss a new VLBA program to investigate structural and polarization changes in the brightest AGN jets in the northern sky. Our study represents a significant improvement over previous surveys in terms of image fidelity, size, and…

天体物理学 · 物理学 2007-05-23 M. L. Lister

We report on multi-frequency linear polarization monitoring of 15 active galactic nuclei containing highly relativistic jets with apparent speeds from $\sim$4 $c$ to $>40c$. The measurements were obtained at optical, 1 mm, and 3 mm…

We discuss optical (HST/WFPC2 F555W) and radio (15 GHz VLA) polarimetry observations of the M87 jet taken during 1994-1995. Many knot regions are very highly polarized ($\sim 40-50%$, approaching the theoretical maximum for optically thin…

天体物理学 · 物理学 2009-10-31 Eric S. Perlman , John A. Biretta , Fang Zhou , William B. Sparks , F. Duccio Macchetto

The magnetic field is believed to play a critical role in the bulk acceleration and propagation of jets produced in active galactic nuclei (AGN). Polarization observations of AGN jets provide valuable information about their magnetic…

高能天体物理现象 · 物理学 2022-10-26 Jongho Park , Juan Carlos Algaba

We present a stationary, axisymmetric, self-similar semi-analytic model of magnetically dominated jet plasma based on force-free regions of a relativistic magnetohydrodynamic simulation. We use this model to illustrate how the composition…

高能天体物理现象 · 物理学 2021-01-18 Richard Anantua , Razieh Emami , Abraham Loeb , Andrew Chael

Radio polarimetry is an invaluable tool to investigate the physical conditions and variability processes in active galactic nuclei (AGN) jets. However, detecting their linear and circular polarization properties is a challenging endeavor…

高能天体物理现象 · 物理学 2016-11-30 Ioannis Myserlis , Emmanouil Angelakis , Alex Kraus , Lars Fuhrmann , Vassilis Karamanavis , J. Anton Zensus

A detailed analysis of the evolution of the properties of core-jet systems within the VLBA Imaging and Polarimetry Survey (VIPS) is presented. We find a power-law relationship between jet intensity and width that suggests for the typical…

天体物理学 · 物理学 2009-11-13 J. F. Helmboldt , G. B. Taylor , R. C. Walker , R. D. Blanford

We present polarization-sensitive images from the Karl G. Jansky Very Large Array (VLA) at 5 GHz of 11 radio-quiet PG quasars. Based on the radio morphology, spectral index and polarization properties from the VLA study, coupled with the…

星系天体物理 · 物理学 2024-02-21 Silpa S. , P. Kharb , Luis C. Ho , C. M. Harrison

We present the first polarimetric space VLBI imaging observations at 22 GHz. BL Lacertae was observed in 2013 November 10 with the RadioAstron space VLBI mission, including a ground array of 15 radio telescopes. The instrumental…

The morphology of spectral line polarization is the most valuable observable to investigate the magnetic and dynamic solar atmosphere. However, in order to develop solar diagnosis, it is fundamental to understand the different kinds of…

太阳与恒星天体物理 · 物理学 2019-07-03 Edgar S. Carlin

We describe a geometric model for synchrotron and synchrotron self-Compton (SSC) radiation from blazar jets, involving multiple emission zones with turbulent magnetic fields and fully self-consistent seed photon mixing for SSC. Including…

高能天体物理现象 · 物理学 2020-01-08 A. L. Peirson , R. W. Romani

We have analyzed the total intensity, spectral index, linear polarization, and RM distributions at pc scale for the quasar 1604+159. The source was observed in 2002 and 2020 with the VLBA. Combining the MOJAVE results, we studied the…

高能天体物理现象 · 物理学 2024-02-02 Xu-Zhi Hu , Xiaoyu Hong , Wei Zhao , Liang Chen , Wei-Yang Wang , Linhui Wu

The jets emanating from the centers of active galactic nuclei (AGN) are among the most energetic objects in the universe. Investigating how the morphology of the jet's synchrotron emission depends on the magnetic nature of the jet's…

高能天体物理现象 · 物理学 2021-12-15 Joana A. Kramer , Nicholas R. MacDonald