Results 1 to 10 of about 11,678 (196)
Micro-Arcsecond Radio Astrometry [PDF]
Annual Review of Astronomy and Astrophysics, 2013 Astrometry provides the foundation for astrophysics. Accurate positions are required for the association of sources detected at different times or wavelengths, and distances are essential to estimate the size, luminosity, mass, and ages of most objects ...
Honma, M., Reid, M. J.
core +2 more sources
The Radio Fundamental Catalog. I. Astrometry
The Astrophysical Journal Supplement SeriesWe 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 (VLBI) observing ...
L. Y. Petrov, Y. Y. Kovalev
doaj +3 more sources
Radio Astrometry at Different Frequencies
The Astronomical JournalThe very long baseline interferometry technique allows us to determine the positions of thousands of radio sources using the absolute astrometry approach. I have investigated the impacts of a selection of observing frequencies in a range from 2 to 43 GHz
Leonid Petrov
doaj +2 more sources
Software and Techniques for VLBI Data Processing and Analysis
Universe, 2022 Very-long-baseline interferometry (VLBI) is a challenging observational technique, which requires in-depth knowledge about radio telescope instrumentation, interferometry, and the handling of noisy data.
Michael Janssen +2 more
doaj +1 more source
Position and Proper Motion of Sagittarius A* in the ICRF3 Frame from VLBI Absolute Astrometry
The Astronomical Journal, 2023 Sagittarius A* (Sgr A*) is a strong, compact radio source believed to be powered by a supermassive black hole at the galactic center. Extinction by dust and gas in the galactic plane prevents observing it optically, but its position and proper motion ...
David Gordon +2 more
doaj +1 more source
Demonstration of Ultrawideband Polarimetry Using VLBI Exploration of Radio Astrometry (VERA)
Galaxies, 2022 We report on recent technical developments in the front- and back-ends for the four 20 m radio telescopes of the Japanese Very-Long-Baseline Interferometry (VLBI) project, VLBI Exploration of Radio Astrometry (VERA). We present a brief overview of a dual-
Yoshiaki Hagiwara +5 more
doaj +1 more source
Toward Microarcsecond Astrometry for the Innermost Wobbling Jet of the BL Lacertae Object OJ 287
The Astrophysical Journal Letters, 2023 The BL Lacertae object OJ 287 is a very unusual quasar producing a wobbling radio jet and some double-peaked optical outbursts with a possible period of about 12 yr for more than one century.
Xiaopeng Cheng +5 more
doaj +1 more source
VLBI MultiView Astrometry of Radio Stars
Proceedings of 15th European VLBI Network Mini-Symposium and Users' Meeting — PoS(EVN2022), 2023 The expected emission mechanisms for radio loud M dwarfs include plasma emission, gyrosynchrotron emission during short lived (<2 hrs) flares, and Electron Cyclotron Maser Instability (ECMI) which can occur in planetary aurorae, and interaction between a star and a planetary companion.
Boven, E.P. +3 more
openaire +3 more sources
The Million Quasars (Milliquas) Catalogue, v8
The Open Journal of Astrophysics, 2023 Announcing the final release, v8, of the Milliquas (Million Quasars) quasar catalogue which presents all published quasars to 30 June 2023, including quasars from the first releases of the Dark Energy Spectroscopic Instrument (DESI) and the SDSS-DR18 ...
Eric Wim Flesch
doaj +1 more source
Overview and Status of the International Celestial Reference Frame as Realized by VLBI
Universe, 2022 Accurate measurement of angular positions on the sky requires a well-defined system of reference that is realized with accessible objects. The purpose of this study is to review the international standard realization of such a system, the International ...
Aletha de Witt +3 more
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