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Related papers: High Precision Differential Astrometry

200 papers

Context: The Deep Extragalactic VLBI-Optical Survey (DEVOS) aims at constructing a large sample of compact radio sources up to two orders of magnitude fainter than those studied in other Very Long Baseline Interferometry (VLBI) surveys.…

Astrophysics · Physics 2008-01-09 S. Frey , L. I. Gurvits , Z. Paragi , L. Mosoni , M. A. Garrett , S. T. Garrington

The NRAO Very Long Baseline Array (VLBA) was used at 1.4 GHz to image 20 compact sources in the inner 1-degree radius of the Spitzer VLA First-Look Survey. Twelve sources were detected with the VLBA, with peak flux densities above 2 mJy at…

Astrophysics · Physics 2009-11-10 J. M. Wrobel , M. A. Garrett , J. J. Condon , R. Morganti

The conventional approach to high-precision narrow-angle astrometry using a long baseline interferometer is to directly measure the fringe packet separation of a target and a nearby reference star. This is done by means of a technique known…

Instrumentation and Methods for Astrophysics · Physics 2014-08-25 Y. Kok , M. J. Ireland , A. C. Rizzuto , P. G. Tuthill , J. G. Robertson , B. A. Warrington , W. J. Tango

The Korean VLBI Network (KVN) is a new mm-VLBI dedicated array with capability for simultaneous observations at multiple frequencies, up to 129 GHz. The innovative multi-channel receivers present significant benefits for astrometric…

Current detection methods of planetary companions do not allow retrieving their spectral information properties. The method of Differential Interferometry has the potential to complement such information by comparing interferometric…

Lucky Imaging is now an established observing procedure that delivers near diffraction-limited images in the visible on ground-based telescopes up to ~2.5 m in diameter. Combined with low order adaptive optics it can deliver resolution…

Instrumentation and Methods for Astrophysics · Physics 2015-06-15 Craig Mackay

One major goal in fast radio burst science is to detect fast radio bursts (FRBs) over a wide field of view without sacrificing the angular resolution required to pinpoint them to their host galaxies. Wide-field detection and localization…

Astronomical imaging can be broadly classified into two types. The first type is amplitude interferometry, which includes conventional optical telescopes and Very Large Baseline Interferometry (VLBI). The second type is intensity…

Instrumentation and Methods for Astrophysics · Physics 2022-05-04 Manuel Bojer , Zixin Huang , Sebastian Karl , Stefan Richter , Pieter Kok , J. von Zanthier

Angular differential imaging is a high-contrast imaging technique that reduces quasi-static speckle noise and facilitates the detection of nearby companions. A sequence of images is acquired with an altitude/azimuth telescope while the…

Astrophysics · Physics 2009-11-13 C. Marois , D. Lafreniere , R. Doyon , B. Macintosh , D. Nadeau

A catalog containing milliarcsecond--accurate positions of 1332 extragalactic radio sources distributed over the northern sky is presented - the Very Long Baseline Array Calibrator Survey (VCS1). The positions have been derived from…

Astrophysics · Physics 2010-04-06 A. J. Beasley , D. Gordon , A. B. Peck , L. Petrov , D. S. MacMillan , E. B. Fomalont , C. Ma

Multi-messenger astronomy is of great interest. The localization speed of gravitational wave sources is important for the success of electromagnetic follow-up. Although current gravitational wave source localization methods take up to a few…

High Energy Astrophysical Phenomena · Physics 2021-03-17 Takuya Tsutsui , Kipp Cannon , Leo Tsukada

We determined the separations of the radio sources in the triangle formed by the BL Lac objects 1803+784 and 2007+777, and the QSO 1928+738 from intercontinental interferometric observations carried out in November 1991 at the frequencies…

The shear number of sources that will be detected by next-generation radio surveys will be astronomical, which will result in serendipitous discoveries. Data-dependent deep hashing algorithms have been shown to be efficient at image…

Computer Vision and Pattern Recognition · Computer Science 2023-09-06 Steven Ndung'u , Trienko Grobler , Stefan J. Wijnholds , Dimka Karastoyanova , George Azzopardi

Various sign-posts of recent star-formation activity, such as water and methanol maser emission or magnetically active low-mass young stars, can be detected with Very Long Baseline Interferometry (VLBI) radio arrays. The extremely accurate…

Astrophysics of Galaxies · Physics 2018-10-17 Laurent Loinard , Mark J. Reid

We consider a possibility of detecting the jitter effect of apparent celestial positions of distant sources due to local fluctuations of the Galaxy gravitational field. It is proposed to observe two samples of extragalactic sources (target…

Astrophysics of Galaxies · Physics 2020-07-29 Tatiana I. Larchenkova , Natalia Lyskova , Leonid Petrov , Alexander A. Lutovinov

Many adaptive optics systems operate by measuring the distortion of the wavefront in one wavelength range and performing the scientific observations in a second, different wavelength range. One common technique is to measure wavefront…

Astrophysics · Physics 2009-11-07 Henry G. Roe

A relativistic delay model for space very long baseline interferometry (hereafter SVLBI) observation of sources at infinite distance is derived. In SVLBI, where one station is on a spacecraft, the orbiting station's maximum speed in an…

Instrumentation and Methods for Astrophysics · Physics 2014-06-19 Shi-Long Liao , Zheng-Hong Tang , Zhao-Xiang Qi

Very long baseline interferometry (VLBI) provides the highest-resolution images in astronomy. The sharpest resolution is nominally achieved at the highest frequencies, but as the observing frequency increases so too does the atmospheric…

(abridged) Very long baseline interferometry (VLBI) observations at 86$\,$GHz (wavelength, $\lambda = 3\,$mm) reach a resolution of about 50 $\mu$as, probing the collimation and acceleration regions of relativistic outflows in active…

The current state of the link problem between radio and optical celestial reference frames is considered. The main objectives of the investigations in this direction during the next few years are the preparation of a comparison and the…

Instrumentation and Methods for Astrophysics · Physics 2016-09-27 Zinovy Malkin