Results 51 to 60 of about 13,426 (202)
Metrics and Motivations for Earth–Space VLBI: Time-resolving Sgr A* with the Event Horizon Telescope [PDF]
Astrophysical Journal, 2019 Very-long-baseline interferometry (VLBI) at frequencies above 230 GHz with Earth-diameter baselines gives spatial resolution finer than the ∼50 μas “shadow” of the supermassive black hole at the Galactic Center, Sagittarius A* (Sgr A*).
D. Palumbo +4 more
semanticscholar +1 more source
Imaging black holes and jets with a VLBI array including multiple space-based telescopes [PDF]
, 2019 Very long baseline interferometry (VLBI) from the ground at millimeter wavelengths can resolve the black hole shadow around two supermassive black holes, Sagittarius A∗ and M87. The addition of modest telescopes in space would allow the combined array to
V. Fish, M. Shea, K. Akiyama
semanticscholar +1 more source
Decoherence in LOFAR-VLBI beamforming [PDF]
Astronomy & Astrophysics, 2020 We show that the use of a superstation (a phased array created using multiple stations of an interferometric array) created in post-processing for LOFAR-VLBI observations introduces a direction-dependent loss of signal in the image. We show this effect using simulations and real data.
Bonnassieux E. +3 more
openaire +3 more sources
A Study on the Development of Playback Control Software for Mark5B VSI System [PDF]
Journal of Astronomy and Space Sciences, 2010 We developed the playback control software for a high-speed playback system which is a component of the Korea-Japan Joint VLBI Correlator (KJJVC). The Mark5B system, which is a recorder and playback system used in the Korean VLBI Network (KVN), has two
S. J. Oh +5 more
doaj +1 more source
Space VLBI: from first ideas to operational missions [PDF]
Advances in Space Research, 2019 The operational period of the first generation of dedicated Space VLBI (SVLBI) missions commenced in 1997 with the launch of the Japan-led mission VSOP/HALCA and is coming to closure in 2019 with the completion of in-flight operations of the Russia-led ...
L. Gurvits
semanticscholar +1 more source
Ground Based VLBI Facilities - the European and Global VLBI Network [PDF]
, 2004 11 pages, 5 figures, lecture presented at the NATA ASI VLBI School, Oct 2001. To be published in "The Role of VLBI in Astrophysics, Astrometry and Geodesy", ed. F. Mantovani.
openaire +2 more sources
Preparation of the VIRAC Radio Telescope RT-32 for e-VLBI Observations
Open Astronomy, 2013 A fully steerable parabolic antenna RT-32 with the mirror diameter 32 m owned by the Ventspils International Radio Astronomy Centre (VIRAC) is available for fundamental and applied research in radio astronomy.
Skirmante K. +3 more
doaj +1 more source
A comparison of the local spiral structure from Gaia DR2 and VLBI maser parallaxes [PDF]
Astronomy & Astrophysics, 2018 Context. The Gaia mission has released the second data set (Gaia DR2), which contains parallaxes and proper motions for a large number of massive, young stars. Aims.
Ye Xu +10 more
semanticscholar +1 more source
Symposium - International Astronomical Union, 2001 Space VLBI enables high angular resolution and high dynamic range imaging through an extension of ground-based VLBI. The TDRSS space VLBI experiments in the 1980s were followed by the first space VLBI imaging mission, VSOP, in the 1990s. The new century holds the promise of the VSOP-2 and ARISE missions, which aim for more sensitive, higher angular ...
openaire +1 more source
An Experiment on Radio Location of Objects in the Near-Earth Space with VLBI in 2012
Open Astronomy, 2013 An experiment on radar location of space debris objects using of the method of VLBI was carried out in April, 2012. The radar VLBI experiment consisted in irradiation of some space debris objects (4 rocket stages and 5 inactive satellites) with a signal ...
Nechaeva M. +20 more
doaj +1 more source