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Related papers: Precision VLBI astrometry: Instrumentation, algori…

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We present in this paper accurate positions of 857 sources derived from the astrometric analysis of 16 eleven-hour experiments from the Very Long Baseline Array imaging and polarimetry survey at 5 GHz (VIPS). Among observed sources,…

Cosmology and Nongalactic Astrophysics · Physics 2011-11-22 Leonid Petrov , Gregory Taylor

Extraterrestrial communication signals are hypothesized to be present in an extensive search space. Using principles of communication theory and system design, methods are studied and implemented to reduce the signal search space, while…

Signal Processing · Electrical Eng. & Systems 2024-04-16 William J. Crilly

We report astrometric results of VLBI phase-referencing observations of 22 GHz \hho\ masers emission toward the red hypergiant \vxsgr, one of most massive and luminous red hypergiant stars in our Galaxy, using the Very Long Baseline Array.…

Instrumentation and Methods for Astrophysics · Physics 2018-05-23 Shuangjing Xu , Bo Zhang , Mark J. Reid , Karl M. Menten , Xingwu Zheng , Guangli Wang

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

We use a Bayesian approach to derive the distance probability distribution for one object from its parallax with measurement uncertainty for two spatial distribution priors, viz. a homogeneous spherical distribution and a galactocentric…

High Energy Astrophysical Phenomena · Physics 2016-06-29 A. P. Igoshev , F. Verbunt , E. Cator

The Palomar High-precision Astrometric Search for Exoplanet Systems (PHASES) monitored 51 sub-arcsecond binary systems to determine precision binary orbits, study the geometries of triple and quadruple star systems, and discover previously…

Instrumentation and Methods for Astrophysics · Physics 2015-05-20 Matthew W. Muterspaugh , Benjamin F. Lane , S. R. Kulkarni , Maciej Konacki , Bernard F. Burke , M. M. Colavita , M. Shao , Sloane J. Wiktorowicz , J. O'Connell

The high angular resolution and sensitivity of Very Long Baseline Interferometry (VLBI) offer a unique tool to identify and study active galactic nuclei and star-formation activity over cosmic time. However, despite recent technical…

Astrophysics of Galaxies · Physics 2024-12-05 Célestin Herbé-George , J. P. Mckean , Raffaella Morganti , Jack F. Radcliffe

The Laser Interferometer Space Antenna (LISA) is a gravitational wave detector in space. It relies on a post-processing technique named time-delay interferometry (TDI) to suppress the overwhelming laser frequency noise by several orders of…

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 2008-12-18 G. Bourda , P. Charlot , R. Porcas , S. Garrington

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

It is expected that the European Space Agency mission Gaia will make possible to determine coordinates in the optical domain of more than 500000 quasars. In 2006, a radio astrometry project was launched with the overall goal to make…

Cosmology and Nongalactic Astrophysics · Physics 2011-11-22 Leonid Petrov

We present a series of sixteen Very Long Baseline Array (VLBA) high angular resolution observations of a cluster of suspected low-mass young stars in the Monoceros R2 region. Four compact and highly variable radio sources are detected;…

Recent advances in VLBI have led to astrometric accuracy exceeding that of the Gaia mission goals. This chapter describes some important astrophysical problems that can be addressed with sub-milliarcsecond imaging and micro-arcsecond…

Astrophysics of Galaxies · Physics 2018-10-17 Mark Reid , Laurent Loinard , Thomas Maccarone

The Southern Galactic Plane Survey (SGPS) is a radio survey in the 21 cm H I line and in 1.4 GHz full-polarization continuum, observed with the Australia Telescope Compact Array and the Parkes 64m single dish telescope. The survey spans a…

Astrophysics · Physics 2009-11-11 M. Haverkorn , B. M. Gaensler , N. M. McClure-Griffiths , J. M. Dickey , A. J. Green

Pulsar positions can be measured with high precision using both pulsar timing methods and very-long-baseline interferometry (VLBI). Pulsar timing positions are referenced to a solar-system ephemeris, whereas VLBI positions are referenced to…

In the two decades since the first extra-solar planet was discovered, the detection and characterization of extra-solar planets has become one of the key endeavors in all of modern science. Recently direct detection techniques such as…

We present the second catalogue of accurate positions and correlated flux densities for 1100 compact extragalactic radio sources that were not observed before 2008 at high angular resolution. The catalogue spans the declination range -90…

Instrumentation and Methods for Astrophysics · Physics 2019-04-15 Leonid Petrov , Alet de Witt , Elaine M. Sadler , Chris Phillips , Shinji Horiuchi

We present the results of the pilot observations of the Deep Extragalactic VLBI-Optical Survey (DEVOS). Our ultimate aim is to collect information on compact structures in a large sample of extragalactic radio sources (~10000 objects) up to…

Astrophysics · Physics 2009-11-13 L. Mosoni , S. Frey , L. I. Gurvits , M. A. Garrett , S. T. Garrington , Z. I. Tsvetanov

delta Equulei is among the most well-studied nearby binary star systems. Results of its observation have been applied to a wide range of fundamental studies of binary systems and stellar astrophysics. It is widely used to calibrate and…

The most powerful tool for measuring distances within our Galaxy is the annual parallax. We carried out phase-referencing VLBI observations of H$_{2}$O masers in the star forming region W3(OH) with respect to the extragalactic continuum…

Astrophysics · Physics 2007-05-23 K. Hachisuka , A. Brunthaler , Y. Hagiwara , K. M. Menten , H. Imai , M. Miyoshi , T. Sasao