Results 31 to 40 of about 11,697 (215)
Unconstrained Estimation of VLBI Global Observing System Station Coordinates [PDF]
Advances in Geosciences, 2021 The International VLBI Service for Geodesy and Astrometry (IVS) is currently setting up a network of smaller and thus faster radio telescopes observing at broader bandwidths for improved determination of geodetic parameters. However, this new VLBI Global
M. Mikschi +3 more
doaj +1 more source
Science with radio pulsar astrometry [PDF]
Proceedings of the International Astronomical Union, 2012 AbstractHigh precision astrometry on radio pulsars can provide model-independent estimates of their distances and velocities. Such estimates serve to calibrate models of the Galactic electron density distribution, thereby improving distance estimates for the entire pulsar population.
openaire +1 more source
Astrometry of circumstellar masers [PDF]
, 2002 The circumstellar masers around evolved stars offer an interesting possibility to measure stellar parameters through VLBI astrometry. In this paper the application of this technique is discussed, including the accuracy and the uncertainties of the method.
A Eckart +6 more
core +2 more sources
An Updated Reference Frame for the Galactic Inner Parsec
The Astrophysical Journal, 2023 Infrared observations of stellar orbits about Sgr A* probe the mass distribution in the inner parsec of the Galaxy and provide definitive evidence for the existence of a massive black hole.
Jeremy Darling +5 more
doaj +1 more source
RADIO ASTROMETRY OF THE TRIPLE SYSTEMS ALGOL AND UX ARIETIS [PDF]
The Astrophysical Journal, 2011 We have used multi-epoch long-baseline radio interferometry to determine the proper motion and orbital elements of Algol and UX Arietis, two radio-bright, close binary stellar systems with distant tertiary components. For Algol, we refine the proper motion and outer orbit solutions, confirming the recent result of Zavala et al.
Peterson, W. M. +4 more
openaire +4 more sources
VERA’s 20 yr Evolution in Science and Technology
GalaxiesWe review the past 20 yr evolution of VERA (VLBI Exploration of Radio Astrometry) in both science and techinology. VERA is a VLBI array in Japan which consists of four 20 m-diameter telescopes, originally dedicated to phase-referencing VLBI astrometry ...
Mareki Honma +3 more
doaj +1 more source
The Astrophysical Journal, 2023 We have observed the low-mass protostellar source IRAS 15398−3359 at a resolution of 0.″2–0.″3, as part of the Atacama Large Millimeter/Submillimeter Array Large Program FAUST, to examine the presence of a hot corino in the vicinity of the protostar.
Yuki Okoda +18 more
doaj +1 more source
The VERA project (VLBI Exploration of Radio Astrometry) [PDF]
Proceedings of the International Astronomical Union, 2004 VLBI – Very Long Baseline Interferometry – is a radio interferometry technique which provides the highest spatial resolution observations to human kind. But at the present, the accuracy of the astrometry observations is limited by the atmospheric light path variations and instrumental phase errors, and only group delay measurements are used.
Hideyuki Kobayashi +9 more
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The jet of the Low Luminosity AGN of M81
EPJ Web of Conferences, 2013 In this contribution, we summarize our main results of a big campaign of global VLBI observations of the AGN in M81 (M81*) phase-referenced to the radio supernova SN 1993J.
Alberdi A. +6 more
doaj +1 more source
, 1995 In this pilot investigation, precise optical positions in the FK5 system are presented for a set of 16 compact extragalactic radio sources, which will be part of the future radio--optical reference frame.
de Vegt, C. +3 more
core +1 more source