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Extension of radio interferometric baselines into space is inevitable if a diffraction-limited angular resolution defined by the Earth diameter at a given observing wavelength limits a pursuit of specific scientific goals. This was…

Instrumentation and Methods for Astrophysics · Physics 2018-10-03 Leonid I. Gurvits

As part of an on-going study of radio transients in Epoch 1 (2017-2019) of the Very Large Array Sky Survey (VLASS), we have discovered a sample of 0.2<z<3.2 active galactic nuclei (AGN) selected in the optical/infrared that have recently…

We present the largest and deepest late-time radio and millimeter survey to date of superluminous supernovae (SLSNe) and long duration gamma-ray bursts (LGRBs) to search for associated non-thermal synchrotron emission. Using the Karl G.…

Aims. The X-ray luminous and radio-loud AGN SRGE J170245.3+130104 discovered at z $\sim$ 5.5 provides unique chances to probe the SMBH growth and evolution with powerful jets in the early Universe. Methods. We present 1.35 - 5.1 GHz Very…

We report the most important results on the parsec-scale properties of a complete sample of radio galaxies carried out at radio frequencies with the Global VLBI array and with the VLBA. Relativistic parsec-scale jets are common both in FRI…

Astrophysics · Physics 2007-05-23 T. Venturi , G. Giovannini , L. Feretti , W. D. Cotton , L. Lara

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

GHz-peaked spectrum (GPS) radio sources are thought to be young objects which later evolve into FR-I and FR-II radio galaxies. We have used the Australia Telescope 20GHz (AT20G) survey catalogue to select a uniform sample of GPS sources…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Paul J. Hancock , Steven J. Tingay , Elaine M. Sadler , Chris Phillips , Adam T. Deller

The paper presents the results of the largest to date VLBI absolute astrometry campaign of observations of 13,645 radio sources with the Very Long Baseline Array (VLBA). Of them, 7220 have been detected, including 6755 target sources that…

Instrumentation and Methods for Astrophysics · Physics 2020-12-16 Leonid Petrov

We analytically model stationary and axisymmetric active galactic nucleus jets, assuming energy conservation along each magnetic flux tube. Using very-long-baseline interferometry (VLBI) observations and published general relativistic…

High Energy Astrophysical Phenomena · Physics 2025-08-11 Kouichi Hirotani , Hsien Shang , Ruben Krasnopolsky , Satoki Matsushita , Britton Jeter , Keiichi Asada

We discuss possibilities and improvements which could be obtained, if a phased array with a large number (N=50-100) of sub-millimeter antennas - like the planned large southern array (the former LSA, now ALMA) is used for…

Astrophysics · Physics 2007-05-23 Thomas P. Krichbaum

In order to directly study the role of magnetic fields in the immediate vicinity of protostars, we use Very-Long-Baseline Interferometry (VLBI), aiming at the detection of non-thermal centimetric radio emission. This is technically the only…

Astrophysics · Physics 2009-11-13 Jan Forbrich , Maria Massi , Eduardo Ros , Andreas Brunthaler , Karl Menten

Extending geodetic and astrometric Very Long Baseline Interferometry (VLBI) observations from traditional centimeter wavebands to millimeter wavebands offers numerous scientific potentials and benefits. However, it was considered quite…

The study of jet launching in AGN is an important research method to better understand supermassive black holes (SMBHs) and their immediate surroundings. The main theoretical jet launching scenarios invoke either magnetic field lines…

Astrophysics of Galaxies · Physics 2023-12-05 G. F. Paraschos , J. -Y. Kim , T. P. Krichbaum , J. Oh , J. A. Hodgson , M. A. Gurwell , J. A. Zensus

We investigate statistical and individual astrophysical properties of active galactic nuclei (AGNs), such as parsec-scale flux density, core dominance, angular and linear sizes, maximum observed brightness temperatures of VLBI core…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-20 A. B. Pushkarev , Y. Y. Kovalev

Very long baseline interferometry (VLBI) observations show that some active galactic nuclei (AGN) jets exhibit bending even at parsec scales. The nature of bending is comprehensively analysed only for a small number of individual AGN, and…

High Energy Astrophysical Phenomena · Physics 2023-10-05 V. A. Makeev , Y. Y. Kovalev , A. B. Pushkarev

From a combination of MERLIN (Multi-Element Radio-Linked Interferometer Network) and global VLBI (Very Long Baseline Interferometry) observations of the starburst galaxy M82, images of 36 discrete sources at resolutions ranging from ~3 to…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 D. Fenech , R. Beswick , T. W. B. Muxlow , A. Pedlar , M. K. Argo

In this paper I outline a new strategy for the routine detection and imaging of faint (sub-mJy and microJy) radio sources with VLBI and SVLBI. The strategy relies on a combination of in-beam phase-referencing, wide-field VLBI imaging and…

Astrophysics · Physics 2007-05-23 M. A. Garrett

Physical parameters of AGN jets observed with Very Long Baseline Interferometry (VLBI) are usually inferred from the core shift measurements or flux and size measured at a peak frequency of the synchrotron spectrum. Both are preceded by…

Astrophysics of Galaxies · Physics 2019-08-05 Ilya N. Pashchenko , Alexander V. Plavin

The results of VLBI observations of the quasar 3C273, obtained during a multi-frequency campaign in late 1992 in the radio, millimeter and X-ray bands are presented and discussed. The VLBI observations were made at 22 GHz with a Global…

Astrophysics · Physics 2007-05-23 F. Mantovani , W. Junor , C. Valerio , I. McHardy

We present results of single-epoch very long baseline interferometry (VLBI) observations of gamma-ray bright active galactic nuclei (AGNs) using the Korean VLBI Network (KVN) at 22, 43, 86, and 129~GHz bands, which are part of a KVN key…