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Related papers: Software and techniques for VLBI data processing a…

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Context: To investigate the differences between positions, as determined by optical (direct imaging) and Very Long Baseline Interferometry (VLBI) techniques, of extragalactic sources listed in the second realization of the International…

Astrophysics of Galaxies · Physics 2015-05-28 J. I. B. Camargo , A. H. Andrei , M. Assafin , R. Vieira-Martins , D. N. da Silva Neto

Context: We introduce the computation of global reference frames from Very Long Baseline Interferometry (VLBI) observations at the Vienna International VLBI Service for Geodesy and Astrometry (IVS) Analysis Center (VIE) in detail. We focus…

Instrumentation and Methods for Astrophysics · Physics 2023-11-08 H. Krásná , L. Baldreich , J. Böhm , S. Böhm , J. Gruber , A. Hellerschmied , F. Jaron , L. Kern , D. Mayer , A. Nothnagel , O. Panzenböck , H. Wolf

VLBI at millimeter wavelengths (mm-VLBI) allows the detailed imaging of compact galactic and extragalactic radio sources with micro-arcsecond scale resolution, unaccessible by other observing techniques. Here we discuss the scientific…

Astrophysics · Physics 2007-05-23 T. P Krichbaum , A. Witzel , J. A. Zensus

Reconstructing images from very long baseline interferometry (VLBI) data with sparse sampling of the Fourier domain (uv-coverage) constitutes an ill-posed deconvolution problem. It requires application of robust algorithms maximizing the…

Instrumentation and Methods for Astrophysics · Physics 2022-10-19 Hendrik Müller , Andrei Lobanov

We discuss the present performance and the future perspectives of VLBI in the 3 mm to 0.85 mm observing bands (so called mm-VLBI). The availability of new telescopes and the recent technical development towards larger observing bandwidth…

Astrophysics · Physics 2008-12-23 T. P. Krichbaum , U. Bach , D. A. Graham , W. Alef , A. Roy , A. Witzel , J. A. Zensus , M. Bremer , S. Sanchez

Astrometry at centimeter wavelengths using Very Long Baseline Interferometry is approaching accuracies of ~1 uas for the angle between a target and a calibrator source separated by <1 degree on the sky. The BeSSeL Survey and the Japanese…

Instrumentation and Methods for Astrophysics · Physics 2023-01-13 Mark J. Reid

Very Long Baseline Interferometry (VLBI) provides the highest-resolution radio intensity maps, crucial for detailed studies of compact sources like active galactic nuclei (AGN) and their relativistic jets. Analyzing jet components in these…

Instrumentation and Methods for Astrophysics · Physics 2025-10-02 Alfredo Amador-Portes , Eva Palafox , Víctor M. Patiño-Álvarez , Vahram Chavushyan , Andrei P. Lobanov , Sergio A. Dzib

Context. Very Long Baseline Interferometry (VLBI) data are extremely sensitive to the phase stability of the VLBI array. This is especially important when we reach {\mu}Jy r.m.s. sensitivities. Calibration using standard phase referencing…

Instrumentation and Methods for Astrophysics · Physics 2016-02-24 Jack F. Radcliffe , Michael A. Garrett , Rob J. Beswick , Tom W. B. Muxlow , Peter Barthel , Adam T. Deller , Enno Middelberg

Calibrating large volumes of Very Long Baseline Interferometry (VLBI) data traditionally requires significant human intervention at every stage. While the Common Astronomy Software Applications (CASA) package is the standard data reduction…

Instrumentation and Methods for Astrophysics · Physics 2026-04-21 A. Kumar , C. Casadio , M. Janssen , D. Álvarez-Ortega , F. M. Pötzl

A review is given on the current status and selected results from large VLBI surveys of compact extragalactic radio sources made between 13 cm and 3 mm wavelengths and covering the entire sky. More than 4200 objects are observed and imaged…

Astrophysics · Physics 2009-07-22 Y. Y. Kovalev

The Low Frequency Array (LOFAR) is a new generation of electronic radio telescope based on aperture array technology. The telescope is being developed by ASTRON, and currently being rolled out across the Netherlands and other countries in…

Cosmology and Nongalactic Astrophysics · Physics 2009-03-07 M. A. Garrett , H. Rampadarath , E. Lenc , Olaf Wucknitz

We present results from observation, correlation and analysis of interferometric measurements between the three geodetic very long baseline interferometry (VLBI) stations at the Onsala Space Observatory. In total 25 sessions were observed…

Instrumentation and Methods for Astrophysics · Physics 2021-05-05 Eskil Varenius , Rüdiger Haas , Tobias Nilsson

In this paper a description is given of the SFXC software correlator, developed and maintained at the Joint Institute for VLBI in Europe (JIVE). The software is designed to run on generic Linux-based computing clusters. The correlation…

Modern radio astrometry has reached the limit of the resolution that is determined by the size of the Earth. The only way to overcome that limit is to create the radio telescopes outside our planet. It is proposed to build an autonomous…

Instrumentation and Methods for Astrophysics · Physics 2019-03-21 Sergei L. Kurdubov , Dmitry A. Pavlov , Svetlana M. Mironova , Sergey A. Kaplev

Planetary ephemerides have been developed and improved over centuries. They are a fundamental tool for understanding solar system dynamics, and essential for planetary and small body mass determinations, occultation predictions,…

Instrumentation and Methods for Astrophysics · Physics 2015-06-23 Dayton L. Jones , William M. Folkner , Robert A. Jacobson , Christopher S. Jacobs , Vivek Dhawan , Jon Romney , Ed Fomalont

In this document we layout a new method to achieve "bona fide" high precision Very-Long-Baseline-Interferometry (VLBI) astrometric measurements of frequency-dependent positions of celestial sources (even) in the high (mm-wavelength)…

Instrumentation and Methods for Astrophysics · Physics 2009-10-08 Richard Dodson , Maria J. Rioja

Interferometric observations of stars in late stages of stellar evolution and the impact of VLTI observations are discussed. Special attention is paid to the spectral information that can be derived from these observations and on the…

Astrophysics · Physics 2015-06-24 T. Bloecker , K. -H. Hofmann , G. Weigelt

Over the past few decades, our knowledge of jets produced by active galactic nuclei (AGN) has greatly progressed thanks to the development of very-long-baseline interferometry (VLBI). Nevertheless, the crucial mechanisms involved in the…

High Energy Astrophysical Phenomena · Physics 2017-11-22 B. Boccardi , T. P. Krichbaum , E. Ros , J. A. Zensus

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

In this paper we describe a new approach for mm-VLBI calibration that provides bona-fide astrometric alignment of the mm-wavelength images from a single source, for the measurement of frequency dependent effects, such as `core-shifts' near…

Instrumentation and Methods for Astrophysics · Physics 2017-01-18 Richard Dodson , María Rioja , Sol Molina , José-Luis Gómez