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Related papers: High Resolution Radio Astronomy Using Very Long Ba…

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Radio astronomy provides a unique window on the universe, allowing us to study: non-thermal processes (galactic nuclei, quasars, pulsars) at the highest angular resolution using VLBI, with low opacity. It is the most interesting wave band…

Astrophysics · Physics 2007-05-23 R D Ekers , J F Bell

Context: Phase referencing is a standard calibration technique in radio interferometry, particularly suited for the detection of weak sources close to the sensitivity limits of the interferometers. However, effects from a changing…

Instrumentation and Methods for Astrophysics · Physics 2015-05-18 I. Marti-Vidal , E. Ros , M. A. Perez Torres , J. C. Guirado , S. Jimenez-Monferrer , J. M. Marcaide

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

A review of the current challenges for the understanding of the physics of extragalactic radio jets from supermassive black holes is presented. Also, a prospect is given about how both very long baseline interferometry (VLBI) and…

Astrophysics of Galaxies · Physics 2016-03-22 Ivan Agudo

Millimetre-VLBI is an important tool in AGN astrophysics, but it is limited by short atmospheric coherence times and poor receiver and antenna performance. We demonstrate a new kind of phase referencing for the VLBA, enabling us to increase…

Astrophysics · Physics 2007-05-23 E. Middelberg , A. L. Roy , R. C. Walker , H. Falcke , T. P. Krichbaum

VLBI is unique, among the space geodetic techniques, in its contribution to defining and maintaining the International Celestial Reference Frame, providing precise measurements of coordinates of extragalactic radiosources. The quest for…

The recent development of $\theta\mhyphen\theta$ techniques in pulsar scintillometry has opened the door for new high resolution imaging techniques of the scattering medium. By solving the phase retrieval problem and recovering the…

Instrumentation and Methods for Astrophysics · Physics 2023-08-09 Daniel Baker , Walter Brisken , Marten H. van Kerkwijk , Rik van Lieshout , Ue-Li Pen

The present generation of radio telescopes, combined with powerful new spectrometers, is opening a new age of redshifted radio absorption-line studies. Outfitting of arrays of antennas, such as the European VLBI Network and the upgraded…

Astrophysics · Physics 2007-05-23 F. H. Briggs

We present a graphical interface designed to demonstrate the techniques of radio interferometry used by telescopes like ALMA, e-Merlin, the JVLA and SKA, in a manner accessible to the general public. Interferometry is an observational tech-…

Instrumentation and Methods for Astrophysics · Physics 2012-11-02 Adam Avison , Samuel J George

After decades of efforts, optical long-baseline interferometry has become a mainstream observational technique in terms of operation robustness and user friendliness. Interferometry has opened a new observational window, enabling…

Solar and Stellar Astrophysics · Physics 2025-12-02 H. Sana E. Bordier , K. Deshmukh , A. J. Frost , A. Keskar , C. Lanthermann , R. R. Lefever , L. Mahy , A. A. C. Sander , T. Shenar , F. Tramper

To accurately link the radio and optical Celestial Reference Frames (CRFs) at optical bright end, i.e., with Gaia G band magnitude < 13, increasing number and improving sky distribution of radio stars with accurate astrometric parameters…

Solar and Stellar Astrophysics · Physics 2023-05-03 Wen Chen , Bo Zhang , Jingdong Zhang , Jun Yang , Shuangjing Xu , Yan Sun , Xiaofeng Mai , Fengchun Shu , Min Wang

With the construction of the VLTI (Very Large Telescope Interferometer of the European Observatory ESO for the southern hemisphere) it is now possible to make observations with resolutions of the order of milli-arc-seconds, especially in IR…

Solar and Stellar Astrophysics · Physics 2017-09-22 M. Hadjara

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 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

We revisit the "Cluster-Cluster" or multi-view Very-Long-Baseline-Interferometry (VLBI) technique from the perspective of its synergy with the multi-beam features inherent in the Australian Square Kilometer Array Pathfinder (ASKAP)and its…

Instrumentation and Methods for Astrophysics · Physics 2009-09-28 M. J. Rioja , R. Dodson , R. W. Porcas , D. Ferris , J. Reynolds , T. Sasao , R. T. Schilizzi

The space astrometry mission GAIA will construct a dense optical QSO-based celestial reference frame. For consistency between the optical and radio positions, it will be important to align the GAIA frame and the International Celestial…

Astrophysics · Physics 2009-11-13 Geraldine Bourda , Patrick Charlot , Richard Porcas , Simon Garrington

Extracting polarimetric information from very long baseline interferometry (VLBI) data is demanding but vital for understanding the synchrotron radiation process and the magnetic fields of celestial objects, such as active galactic nuclei…

Instrumentation and Methods for Astrophysics · Physics 2025-11-21 Jong-Seo Kim , Jakob Roth , Jongho Park , Jack D. Livingston , Philipp Arras , Torsten A. Enßlin , Michael Janssen , J. Anton Zensus , Andrei P. Lobanov

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 show how an idealized high-frequency VLBI can probe the metric of nearby supermassive black holes. No quantitative assumptions about plasma dynamics are used in the suggested diagnostic, which is based on strong-field lensing.

Astrophysics · Physics 2007-05-23 Andrei Gruzinov

The African Very Long Baseline Interferometry Network (AVN) is a pan-African project that will develop Very Long Baseline Interferometry (VLBI) observing capability in several countries across the African continent, either by conversion of…