English
Related papers

Related papers: Using Faraday Rotation Gradients to probe Magnetic…

200 papers

Rotation measure observations of 9 quasars, 4 BL Lacertae objects, and 3 radio galaxies are presented. The rest frame rotation measures in the cores of the quasars and the jets of the radio galaxy M87 are several thousand radians per meter…

Astrophysics · Physics 2008-11-26 R. T. Zavala , G. B. Taylor

We used 15 GHz multi-epoch Very Long Baseline Array (VLBA) polarization sensitive observations of 484 sources within a time interval 1996--2016 from the MOJAVE program, and also from the NRAO data archive. We have analyzed the linear…

High Energy Astrophysical Phenomena · Physics 2017-12-11 A. B. Pushkarev , Y. Y. Kovalev , M. L. Lister , T. Savolainen , M. F. Aller , H. D. Aller , M. A. Hodge

A single measurement of linear polarization of a nonthermal source provides direct information about the mean direction and level of ordering of the magnetic field. Monitoring of the polarization in blazars, combined with millimeter-wave…

High Energy Astrophysical Phenomena · Physics 2015-06-23 Alan P. Marscher

We present circular polarization results from a 5 GHz survey of the parsec-scale polarization properties of 40 AGN made with the VLBA. We find 11 circular polarization detections at the 3 sigma level or higher. This nearly quadruples the…

Astrophysics · Physics 2009-11-06 Daniel C. Homan , Joanne M. Attridge , John F. C. Wardle

We present an analysis of the core linear polarization properties of 387 parsec-scale active galactic nuclei (AGN) jets. Using 15 GHz VLBA data, we revisit the conclusions of the first paper in this series with multi-epoch measurements and…

Astrophysics of Galaxies · Physics 2018-08-16 M. A. Hodge , M. L. Lister , M. F. Aller , H. D. Aller , Y. Y. Kovalev , A. B. Pushkarev , T. Savolainen

Active Galactic Nuclei (AGNs) observed with the technique of very long baseline interferometry (VLBI) are used as fiducial references on the sky to precisely measure the shape and orientation of the Earth. Their positions form a celestial…

Astrophysics of Galaxies · Physics 2025-01-31 Ming Hui Xu , Patrick Charlot

Non-VLBI measurements of Faraday rotation at mm wavelengths have been used to constrain mass accretion rates ($\mdot$) onto supermassive black holes in the centre of the Milky Way and in the centre of M87. We constructed general…

High Energy Astrophysical Phenomena · Physics 2017-04-19 Monika Moscibrodzka , Jason Dexter , Jordy Davelaar , Heino Falcke

There is still a limited number of high-redshift ($z>3$) active galactic nuclei (AGN) whose jet kinematics have been studied with very long baseline interferometry (VLBI). Without a dedicated proper motion survey, regularly conducted…

Accurate measurement of the frequency-dependent shift of the self-absorbed radio core is required for multi-frequency analysis of VLBI data since absolute positional information is lost as a result of phase self-calibration. We use the…

Astrophysics · Physics 2008-12-19 Shane P. O'Sullivan , Denise C. Gabuzda

We present images of the jets in the nearby radio galaxy NGC 315 made with the VLA at five frequencies between 1.365 and 5 GHz with resolutions between 1.5 and 45 arcsec FWHM. Within 15 arcsec of the nucleus, the spectral index of the jets…

Astrophysics · Physics 2009-11-11 R. A. Laing , J. R. Canvin , W. D. Cotton , A. H. Bridle

We present an investigation of the compact structure of the AGN 2021+317 based on multi-epoch Very Long Baseline Interferometry (VLBI) observations at 15, 22, and 43 GHz in the period from 2013 through 2024. The VLBI images show a core-jet…

High Energy Astrophysical Phenomena · Physics 2025-07-08 Haitian Shang , Wei Zhao , Xiaoyu Hong , Leonid I. Gurvits , Ailing Zeng , Tao An , Xiaopeng Cheng

The fine-scale structure and the kinematics of relativistic active galactic nuclei (AGN) jets have been studied by very-long-baseline interferometry at very high resolutions since 1998 at 2 cm wavelength for a sample of over a hundred radio…

Astrophysics · Physics 2014-11-18 Eduardo Ros

Modelling of deep VLA images of the jets in FR I radio galaxies has allowed us to derive their three-dimensional distributions of velocity, emissivity and magnetic-field structure on kiloparsec scales. By combining our models of jet…

Astrophysics · Physics 2007-05-23 R. A. Laing

In recent studies, several AGN have exhibited gradients of the Faraday Rotation Measure (RM) transverse to their parsec-scale jet direction. Faraday rotation likely occurs as a result of a magnetized sheath wrapped around the jet. In the…

High Energy Astrophysical Phenomena · Physics 2021-03-26 M. M. Lisakov , E. V. Kravchenko , A. B. Pushkarev , Y. Y. Kovalev , T. K. Savolainen , M. L. Lister

Faraday Rotation Measures (RM) should be interpreted with caution because there could be multiple magneto-ionized medium components that contribute to the net Faraday rotation along sight-lines. We introduce a simple test using Galactic…

Astrophysics of Galaxies · Physics 2021-10-13 Seoyoung Lyla Jung , Naomi M. McClure-Griffiths , Alex S. Hill

Results of high-resolution simultaneous multi-frequency 8.1-15.4 GHz VLBA polarimetric observations of relativistic jets in active galactic nuclei (the MOJAVE-2 project) are analyzed. We compare characteristics of VLBI features with jet…

Astrophysics · Physics 2008-12-31 A. B. Pushkarev , Y. Y. Kovalev , A. P. Lobanov

Observational studies of inner-most regions of the edge-on jets in nearby active galactic nuclei (AGN) are crucial to understand their kinematics and morphology. For the inner jet of the nearby low luminosity AGN in M 84, we present new…

High Energy Astrophysical Phenomena · Physics 2022-12-28 Xuezheng Wang , Wu Jiang , Zhiqiang Shen , Lei Huang , Kazuhiro Hada , Yuzhu Cui , Ru-Sen Lu

Several blazars, and BL Lac objects in particular, show a misalignment between the jet orientation on parsec and kiloparsec scales. Some authors (i.e. Conway & Murphy, 1993) have attempted to explain this behaviour invoking helical jets for…

Astrophysics · Physics 2009-11-07 P. Cassaro , C. Stanghellini , D. Dallacasa , M. Bondi , R. A. Zappalà

We describe the parsec-scale kinematics of 200 AGN jets based on 15 GHz VLBA data obtained between 1994 Aug 31 and 2011 May 1. We present new VLBA 15 GHz images of these and 59 additional AGN from the MOJAVE and 2 cm Survey programs. Nearly…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-17 M. L. Lister , M. F. Aller , H. D. Aller , D. C. Homan , K. I. Kellermann , Y. Y. Kovalev , A. B. Pushkarev , J. L. Richards , E. Ros , T. Savolainen

Using stacking of images obtained at different epochs, we studied the variability properties of linear polarization of active galactic nucleus (AGN) jets on parsec-scales. Our sample is drawn from the MOJAVE programme, and consists of 436…

High Energy Astrophysical Phenomena · Physics 2023-06-16 D. I. Zobnina , H. D. Aller , M. F. Aller , D. C. Homan , Y. Y. Kovalev , M. L. Lister , I. N. Pashchenko , A. B. Pushkarev , T. Savolainen
‹ Prev 1 3 4 5 6 7 10 Next ›