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We present current results from our ongoing project to study the parsec-scale relativistic jet kinematics of sources in the U.S. Naval Observatory's Radio Reference Frame Image Database (RRFID). The RRFID consists of snapshot observations…

Astrophysics · Physics 2007-05-23 B. G. Piner , A. L. Fey , M. Mahmud

(Abridged) We analyze blazar jet apparent speeds and accelerations from the RDV series of astrometric and geodetic VLBI experiments. From these experiments, we have produced and analyzed 2753 global VLBI images of 68 sources at 8 GHz with a…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-20 B. G. Piner , A. B. Pushkarev , Y. Y. Kovalev , C. J. Marvin , J. G. Arenson , P. Charlot , A. L. Fey , A. Collioud , P. A. Voitsik

We present 88 multi-epoch Very Long Baseline Array (VLBA) images (most at an observing frequency of 8 GHz), of 20 TeV blazars, all of the HBL class, that have not been previously studied at multiple epochs on the parsec scale. From these 20…

High Energy Astrophysical Phenomena · Physics 2018-02-14 B. Glenn Piner , Philip G. Edwards

We present results from a large global VLBI(Very Long Baseline Interferometry) survey of compact radio sources at 86 GHz which started in October 2001. The main goal of the survey is to increase the total number of objects accessible for…

Astrophysics · Physics 2009-04-14 S. Lee , A. P. Lobanov , T. P. Krichbaum , A. Witzel , J. A. Zensus , M. Bremer , A. Greve , M. Grewing

VLBA and Global VLBI observations of M87 at 43 GHz, some new and some previously published, are used to study the structural evolution of the jet with a spatial resolution of under 100 Schwarzschild radii. The images, taken between 1999 and…

Astrophysics · Physics 2011-02-11 Chun Ly , R. Craig Walker , William Junor

We have combined Very Long Baseline Interferometry (VLBI) data from several programs in order to resolve differences in reported parsec-scale jet speeds for the TeV gamma-ray source Mkn501. Data from the VLBA 2cm survey, and 8 and 15 GHz…

Astrophysics · Physics 2009-11-07 P. G. Edwards , B. G. Piner

Many of the compact extragalactic radio sources that are used as fiducial points to define the celestial reference frame are known to have proper motions detectable with long-term geodetic/astrometric Very Long Baseline Interferometry…

Cosmology and Nongalactic Astrophysics · Physics 2013-04-16 A. Moór , S. Frey , S. B. Lambert , O. Titov , J. Bakos

We report the results of a 15 GHz (2 cm) multi-epoch VLBA program, begun in 1994 to study the outflow in radio jets ejected from quasars and active galaxies. The observed flow of 208 distinct features measured in 110 quasars, active…

Context: This is the first of a series of papers presenting VLBI observations of the 293 Caltech-Jodrell Bank Flat-Spectrum (hereafter CJF) sources and their analysis. Aims: One of the major goals of the CJF is to make a statistical study…

Context: This is the second of a series of papers presenting VLBI observations of the 293 Caltech-Jodrell Bank Flat-Spectrum (hereafter CJF) sources and their analysis. Aims: To obtain a consistent motion dataset large enough to allow the…

We present images from a long term program (MOJAVE: Monitoring of Jets in AGN with VLBA Experiments) to survey the structure and evolution of parsec-scale jet phenomena associated with bright radio-loud active galaxies in the northern sky.…

We discuss the jet kinematics of a complete flux-density-limited sample of 135 radio-loud active galactic nuclei (AGN) resulting from a 13 year program to investigate the structure and evolution of parsec-scale jet phenomena. Our analysis…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-20 M. L. Lister , M. H. Cohen , D. C. Homan , M. Kadler , K. I. Kellermann , Y. Y. Kovalev , E. Ros , T. Savolainen , J. A. Zensus

We present results of long-term high-frequency VLBI monitoring of the relativistic jet in 3C279, consisting of 18 epochs at 22 GHz from 1991 to 1997 and 10 epochs at 43 GHz from 1995 to 1997. Three major results of this study are: apparent…

Astrophysics · Physics 2008-11-26 A. E. Wehrle , B. G. Piner , S. C. Unwin , A. C. Zook , W. Xu , A. P. Marscher , H. Terasranta , E. Valtaoja

(abridged) Very long baseline interferometry (VLBI) observations at 86$\,$GHz (wavelength, $\lambda = 3\,$mm) reach a resolution of about 50 $\mu$as, probing the collimation and acceleration regions of relativistic outflows in active…

We report on an ongoing effort to image active galactic nuclei simultaneously observed at 2.3 and 8.6 GHz in the framework of a long-term VLBI project RDV (Research and Development - VLBA) started in 1994 aiming to observe compact…

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

A complete sample of 27 radio galaxies was selected from the B2 and 3CR catalogs, in order to study their properties on the milliarcsecond scale. In the Appendix of this paper we present new radio images for 12 of them. Thanks to the…

Astrophysics · Physics 2009-11-06 G. Giovannini , W. D. Cotton , L. Feretti , L. Lara , T. Venturi

Radio-loud quasars at high redshift (z > 4) are rare objects in the Universe and rarely observed with Very Long Baseline Interferometry (VLBI). But some of them have flux density sufficiently high for monitoring of their apparent position.…

We present a multi-epoch and multi-frequency VLBI study of the compact radio source J0650+6001. In VLBI images the source is resolved into three components. The central component shows a flat spectrum, suggesting the presence of the core,…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 M. Orienti , D. Dallacasa

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

Observational studies of GHz peaked spectrum (GPS) sources contribute to the understanding of the radiative properties and interstellar environment of host galaxies. We present the results from the multi-frequency high-resolution VLBI…

High Energy Astrophysical Phenomena · Physics 2023-03-07 Xiaopeng Cheng , Tao An , Ailing Wang , Sumit Jaiswal
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