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Related papers: Potential Targets for ASTRO-G In-Beam Phase-Refere…

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We apply an efficient selection method to identify potential weak Very Long Baseline Interferometry (VLBI) target quasars simply using optical (SDSS) and low-resolution radio (FIRST) catalogue data. Our search is restricted to within 12"…

Astrophysics · Physics 2015-05-13 S. Frey , K. E. Gabanyi , Y. Asaki

We present preliminary results from a VLBI survey at $\lambda=6 $cm of a sample of 35 sources with flux densities of 2 - 100 mJy. These sources were selected from the VLA FIRST survey at $\lambda = 20 $cm, in a 3 degree field around the…

Astrophysics · Physics 2009-10-31 S. T. Garrington , M. A. Garrett , A. Polatidis

It is anticipated that future space-born missions, such as Gaia, will be able to determine in optical domain positions of more than 100,000 bright quasars with sub-mas accuracies that are comparable to very long baseline interferometry…

Instrumentation and Methods for Astrophysics · Physics 2013-06-13 Leonid Petrov

The point source list of the Wilkinson Microwave Anisotropy Probe (WMAP) is a uniform, all-sky catalogue of bright sources with flux density measurements at high (up to 94 GHz) radio frequencies. We investigated the five-year WMAP list to…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-21 K. Gereb , S. Frey

We present a milliarcsecond-resolution radio survey of 17 high-redshift (4 < z < 5.4) blazar candidates observed with the European Very Long Baseline Interferometry (VLBI) Network at 5 GHz. The primary objective of this study was to…

This paper presents the catalog of correlated flux densities in three ranges of baseline projection lengths of 637 sources from a 43 GHz (Q-band) survey observed with the Korean VLBI Network. Of them, 623 sources have not been observed…

Aims. We have analysed VLBA 92cm archive data of 44 extragalactic sources in order to identify early targets and potential calibrator sources for the LOFAR radio telescope and the RadioAstron space VLBI mission. Some of these sources will…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 H. Rampadarath , M. A. Garrett , A. Polatidis

We observed at 22 GHz with the VLBI array VERA a sample of 1536 sources with correlated flux densities brighter than 200 mJy at 8 GHz. One half of target sources has been detected. The detection limit was around 200 mJy. We derived the…

Cosmology and Nongalactic Astrophysics · Physics 2012-07-26 Leonid Petrov , Mareki Honma , Katsunori M. Shibata

We report on the first wide-field, very long baseline interferometry (VLBI) survey at 90 cm. The survey area consists of two overlapping 28 deg^2 fields centred on the quasar J0226+3421 and the gravitational lens B0218+357. A total of 618…

Astrophysics · Physics 2009-11-13 Emil Lenc , Mike A. Garrett , Olaf Wucknitz , James M. Anderson , Steven J. Tingay

A patch of sky in the SDSS Stripe 82 was observed at 1.6 GHz with Very Long Baseline Interferometry (VLBI) using the European VLBI Network (EVN). The data were correlated at the EVN software correlator at JIVE (SFXC). There are fifteen…

Astrophysics of Galaxies · Physics 2014-06-19 H. -M. Cao , S. Frey , L. I. Gurvits , J. Yang , X. -Y. Hong , Z. Paragi , A. T. Deller , Ž. Ivezić

We have obtained 8.4 GHz VLBA observations of a 31-GHz complete sample of ~100 sources between 10 and 100 mJy. The main goals of these observations are: to determine the angular size, radio spectra and identification for a weak sample of…

Astrophysics · Physics 2008-06-19 W. A. Majid , E. B. Fomalont , D. S. Bagri

We investigated the archival ground-based VLBI images of the extragalactic radio sources included in both the {\it Wilkinson Microwave Anisotropy Probe (WMAP)} and the {\it Planck} catalogues, and selected 49 bright and compact sources as…

Astrophysics of Galaxies · Physics 2015-06-19 Tao An , Xiaocong Wu , Sandor Frey

We have used VLBA fringe visibility data obtained at 15 GHz to examine the compact structure in 250 extragalactic radio sources. For 171 sources in our sample, more than half of the total flux density seen by the VLBA remains unresolved on…

Radio-loud active galactic nuclei (AGNs), hosting powerful relativistic jet outflows, provide an excellent laboratory for studying jet physics. Very long baseline interferometry (VLBI) enables high-resolution imaging on milli-arcsecond…

High Energy Astrophysical Phenomena · Physics 2018-02-07 X. -P. Cheng , T. An , X. -Y. Hong , J. Yang , P. Mohan , K. I. Kellermann , M. L. Lister , S. Frey , W. Zhao , Z. -L. Zhang , X. -C. Wu , X. -F. Li , Y. -K. Zhang

High-redshift radio sources provide plentiful opportunities for studying the formation and evolution of early galaxies and supermassive black holes. However, the number of known radio-loud active galactic nuclei (AGN) above redshift 4 is…

Astrophysics of Galaxies · Physics 2022-06-29 M. Krezinger , K. Perger , K. É. Gabányi , S. Frey , L. I Gurvits , Zs. Paragi , T. An , Y. Zhang , H. Cao , T. Sbarrato

The space astrometry mission GAIA will construct a dense optical QSO-based celestial reference frame. For consistency between 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 present results from a large global VLBI(Very Long Baseline Interferometry) survey of compact radio sources at 86 GHz which started in October 2001. The main goal of the survey is to increase the total number of objects accessible for…

Astrophysics · Physics 2009-04-14 S. Lee , A. P. Lobanov , T. P. Krichbaum , A. Witzel , J. A. Zensus , M. Bremer , A. Greve , M. Grewing

We present a catalogue of positions and correlated flux densities of 410 flat-spectrum, compact extragalactic radio sources, previously detected in the AT20G survey. The catalogue spans the declination range -90deg, -40deg and was…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-24 Leonid Petrov , Chris Phillips , Alessandra Bertarini , Tara Murphy , Elaine M. Sadler

We present very long baseline interferometry (VLBI) observations of 179 radio sources in the COSMOS field with extremely high sensitivity using the Green Bank Telescope (GBT) together with the Very Long Baseline Array (VLBA) (VLBA+GBT) at…

We present results from a large 86GHz global VLBI survey of compact radio sources. The main goal of the survey is to increase by factors of 3--5 the total number of objects accessible for future 3-mm VLBI imaging. The survey observations…

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