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The third iteration of the International Celestial Reference Frame (ICRF3) is made up of 4536 quasars observed at S/X bands using Very Long baseline Interferometry (VLBI). These sources are high redshift quasars, typically between $1<z<2$,…

Astrophysics of Galaxies · Physics 2021-09-08 Lucas R. Hunt , Megan C. Johnson , Phillip J. Cigan , David Gordon , John Spitzak

Context. We present a celestial reference frame (CRF) based on the combination of independent, multifrequency radio source position catalogs using nearly 40 years of Very Long Baseline Interferometry observations at the standard geodetic…

Instrumentation and Methods for Astrophysics · Physics 2019-10-02 Maria Karbon , Axel Nothnagel

Small angular scale (high l) studies of cosmic microwave background anisotropies require accurate knowledge of the statistical properties of extragalactic sources at cm-mm wavelengths. We have used a 30 GHz dual-beam receiver (OCRA-p) on…

The third realization of the International Celestial Reference Frame (ICRF3) was adopted in August 2018 and includes positions of extragalactic objects at three frequencies: 8.4 GHz, 24 GHz, and 32 GHz. In this paper, we present celestial…

Instrumentation and Methods for Astrophysics · Physics 2024-04-30 Hana Krasna , David Gordon , Aletha de Witt , Christopher S. Jacobs

The current realization of the International Celestial Reference Frame (ICRF) comprises a total of 717 extragalactic radio sources distributed over the entire sky. An observing program has been developed to densify the ICRF in the northern…

Astrophysics · Physics 2007-05-23 P. Charlot , A. L. Fey , C. S. Jacobs , C. Ma , O. J. Sovers , A. Baudry

We present the results of the flux density measurements at 4.85 GHz and 10.45 GHz of a sample of 5998 NVSS radio sources with the Effelsberg 100 m telescope. The initial motivation was the need to identify the NVSS radio sources that could…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 E. Angelakis , A. Kraus , A. C. S. Readhead , J. A. Zensus , R. Bustos , T. P. Krichbaum , A. Witzel , T. J. Pearson

We present an updated K band (24 GHz) celestial reference frame (CRF) constructed from 3.5 million Very Long Baseline Interferometry (VLBI) observations collected during 211 observing epochs between May 2002 and December 2025 using the Very…

We have conducted a deep radio survey with the Very Large Array at 1.4 GHz of a region containing the Hubble Deep Field. This survey overlaps previous observations at 8.5 GHz allowing us to investigate the radio spectral properties of…

Astrophysics · Physics 2009-10-31 E. A. Richards

Knowledge of the population of radio sources in the range ~2-200 GHz is important for understanding their effects on measurements of the Cosmic Microwave Background power spectrum. We report measurements of the 30 GHz flux densities of 605…

A new realization of the International Celestial Reference Frame (ICRF) is presented based on the work achieved by a working group of the International Astronomical Union (IAU) mandated for this purpose. This new realization, referred to as…

We have used the Australia Telescope Compact Array (ATCA) at 95GHz to carry out continuum observations of 130 extragalactic radio sources selected from the Australia Telescope 20GHz (AT20G) survey. Over 90% of these sources are detected at…

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…

Aims: We computed a celestial reference frame (CRF) from Very Long Baseline Interferometry (VLBI) Global Observing System (VGOS) data after five years of regular observations (155 multi-baseline 24-hour VGOS sessions until 2024.0). In this…

Instrumentation and Methods for Astrophysics · Physics 2024-11-25 Hana Krasna , Christopher S. Jacobs , Matthias Schartner , Patrick Charlot

Aims - We report new Very Large Array polarimetric observations of Compact Steep-Spectrum (CSS) sources at 8.4, 15, and 23GHz. Methods - Using multi-frequency VLA observations we have derived sub-arcsecond resolution images of the total…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 F. Mantovani , A. Rossetti , W. Junor , D. J. Saikia , C. J. Salter

We present the first sample of 31-GHz selected sources to flux levels of 1 mJy. From late 2005 to mid 2007, the Sunyaev-Zel'dovich Array (SZA) observed 7.7 square degrees of the sky at 31 GHz to a median rms of 0.18 mJy/beam. We identify…

We present an all-sky catalog of absolute positions and estimates of correlated flux density of 21,942 compact radio sources determined from processing interferometric visibility data of virtually all very long baseline interferometry…

Instrumentation and Methods for Astrophysics · Physics 2025-01-20 Leonid Petrov , Yuri Y. Kovalev

We present some first results on the variability, polarization and general properties of radio sources selected in a blind survey at 20 GHz, the highest frequency at which a sensitive radio survey has been carried out over a large area of…

From 1979--1996 the Green Bank Interferometer was used by the Naval Research Laboratory to monitor the flux density from 146 compact radio sources at frequencies near 2 and 8 GHz. We filter the ``light curves'' to separate intrinsic…

Astrophysics · Physics 2009-11-11 B. Rickett , T. J. W. Lazio , F. D. Ghigo

This paper presents results of a survey search for bright compact radio sources at 22 GHz with the VERA radio-interferometer. Each source from a list of 2494 objects was observed in one scan for 2 minutes. The purpose of this survey was to…

Astrophysics · Physics 2008-11-26 L. Petrov , T. Hirota , M. Honma , K. M. Shibata , T. Jike , H. Kobayashi
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