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One major goal in fast radio burst science is to detect fast radio bursts (FRBs) over a wide field of view without sacrificing the angular resolution required to pinpoint them to their host galaxies. Wide-field detection and localization…

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…

Space Very Long Baseline Interferometry is a radio astronomy technique distinguished by a record-high angular resolution reaching single-digit microseconds of arc. The paper provides a brief account of the history of developments of this…

Instrumentation and Methods for Astrophysics · Physics 2023-12-27 Leonid I. Gurvits

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 European VLBI Network (EVN) is in the process of establishing an e-VLBI array in which the radio telescopes and the EVN correlator at JIVE are connected in real-time, via high-speed national fibre optic networks and the pan-European…

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

Obtaining a census of active galactic nuclei (AGN) activity across cosmic time is critical to our understanding of galaxy evolution and formation. Many AGN classification techniques are compromised by dust obscuration. However, very long…

Astrophysics of Galaxies · Physics 2021-05-12 J. F. Radcliffe , P. D. Barthel , A. P. Thomson , M. A. Garrett , R. J. Beswick , T. W. B. Muxlow

Very long baseline interferometry (VLBI) is a technique for imaging celestial radio emissions by simultaneously observing a source from telescopes distributed across Earth. The challenges in reconstructing images from fine angular…

Instrumentation and Methods for Astrophysics · Physics 2016-11-08 Katherine L. Bouman , Michael D. Johnson , Daniel Zoran , Vincent L. Fish , Sheperd S. Doeleman , William T. Freeman

Observations of gamma-ray bursts (GRBs) at Very High Energy (VHE) offer a unique opportunity to investigate particle acceleration processes, magnetic fields and radiation fields in these events. Very Long Baseline Interferometry (VLBI)…

The alignment between the radio-based International Celestial Reference Frame (ICRF) and the optical Gaia Celestial Reference Frame (Gaia-CRF) is critical for multi-waveband astronomy, yet systematic offsets at the optical bright end (G<13)…

Compact radio cores in radio-loud active galactic nuclei (AGNs) are classical targets of Very-Long-Baseline interferometric (VLBI) research. Until today little has been known about their X-ray properties in comparison to radio-quiet AGNs.…

Astrophysics · Physics 2007-05-23 M. Kadler , E. Ros , J. Kerp , Y. Y. Kovalev , J. A. Zensus

Ever since the discovery by the Fermi mission that active galactic nuclei (AGN) produce copious amounts of high-energy emission, its origin has remained elusive. Using high-frequency radio interferometry (VLBI) polarization imaging, we…

High Energy Astrophysical Phenomena · Physics 2018-05-15 B. Rani , S. G. Jorstad , A. P. Marscher

We present full polarization Very Long Baseline Array (VLBA) observations at 5 GHz and 15 GHz of 24 compact active galactic nuclei (AGN). These sources were observed as part of a pilot project to demonstrate the feasibility of conducting a…

The radio source M81* at the core of the nearby spiral galaxy M81 is a low-luminosity active galactic nucleus. The close distance of 3.63Mpc allows its morphology to be studied in great detail. Here we present preliminary results from…

Astrophysics · Physics 2008-11-27 Eduardo Ros , Miguel-Angel Perez-Torres

We present a multi-calibrator solution, i.e. MultiView, to achieve accurate astrometry on the level of the thermal noise at low VLBI frequencies dominated by ionospheric residuals. We demonstrate on L-band VLBA observations how MultiView…

Instrumentation and Methods for Astrophysics · Physics 2018-04-10 Gabor Orosz , Maria J. Rioja , Richard Dodson , Hiroshi Imai , Sandor Frey

Using very long baseline interferometry (VLBI) observations at (sub)millimeter wavelengths, the Event Horizon Telescope (EHT) currently achieves the finest angular resolution of any astronomical facility, necessary for imaging the…

Instrumentation and Methods for Astrophysics · Physics 2025-10-23 Uri Rolls , Dominic W. Pesce , Paul Tiede , Lindy Blackburn , Iniyan Natarajan , Sheperd S. Doeleman

We aim to confirm the compact nature and constrain the radio spectra of candidate persistent radio sources (PRSs) associated with repeating fast radio bursts (FRBs). We performed European VLBI Network (EVN) observations at 5 and 8 GHz…

High Energy Astrophysical Phenomena · Physics 2026-04-07 G. Bruni , L. Piro , Y. -P. Yang , L. Nicastro , A. Rossi , E. Palazzi , E. Maiorano , S. Savaglio , B. Zhang

We present an all-sky catalog of absolute positions and estimates of correlated flux density of 21,942 compact radio sources determined from processing interferometric visibility data of virtually all very long baseline interferometry…

Instrumentation and Methods for Astrophysics · Physics 2025-01-20 Leonid Petrov , Yuri Y. Kovalev

The study of compact active galactic nuclei (AGN) that possess convex radio spectra (the gigahertz-peaked spectrum radio sources) offers a unique opportunity to probe both the early evolutionary stages of relativistic AGN jets and their…

Astrophysics · Physics 2007-05-23 M. L. Lister

Blazars are active galactic nuclei (AGN) whose relativistic jets point nearly to the line of sight. Their compact radio structure can be imaged with very long baseline interferometry (VLBI) on parsec scales. Blazars at extremely high…

Astrophysics of Galaxies · Physics 2017-02-12 H. -M. Cao , S. Frey , K. É. Gabányi , Z. Paragi , J. Yang , D. Cseh , X. -Y. Hong , T. An

Long baseline radio interferometers can provide some interesting opportunities for future SETI searches. Known advantages (compared to single dishes or beam-formed arrays), include the large reduction in false-positives due to the…

Instrumentation and Methods for Astrophysics · Physics 2018-10-18 M. A. Garrett
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