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Related papers: High-Resolution Radio Observations of Five Optical…

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We present an analysis of the detection fraction and the number counts of radio sources imaged with Very Long Baseline Interferometry (VLBI) at 1.4 GHz as part of the mJIVE-20 survey. From a sample of 24,903 radio sources identified by…

Astrophysics of Galaxies · Physics 2023-08-31 S. Rezaei , J. P. McKean , A. T. Deller , J. F. Radcliffe

(abbreviated): This paper presents the results of a high resolution radio imaging survey of all known (96) low-luminosity active galactic nuclei (LLAGNs) at D<19Mpc. We find that almost half of all LINERs and low-luminosity Seyferts have…

Astrophysics · Physics 2009-11-07 N. M. Nagar , H. Falcke , A. S. Wilson , J. S. Ulvestad

Observational studies of GHz peaked spectrum (GPS) sources contribute to the understanding of the radiative properties and interstellar environment of host galaxies. We present the results from the multi-frequency high-resolution VLBI…

High Energy Astrophysical Phenomena · Physics 2023-03-07 Xiaopeng Cheng , Tao An , Ailing Wang , Sumit Jaiswal

We have discovered a number of relatively strong radio sources in the field-of-view of SDSS galaxy clusters which present no optical counterparts down to the magnitude limits of the SDSS. The optically faint radio sources appear as…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Mercedes E. Filho , Jarle Brinchmann , Catarina Lobo , Sonia Antón

This paper presents the first high-resolution and high-sensitivity study of the radio properties of optically selected type~2 quasars. We used the Very Large Array at 8.4 GHz to observe 59 sources drawn from the Sloan Digital Sky Survey…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Dharam Vir Lal , Luis C. Ho

We propose a morphological classification based on the parsec scale structure of fifty-one High Frequency Peakers (HFPs) from the ``bright'' HFP sample. VLBA images at two adjacent frequencies (chosen among 8.4, 15.3, 22.2 and 43.2 GHz)…

Astrophysics · Physics 2009-11-11 M. Orienti , D. Dallacasa , S. Tinti , C. Stanghellini

VLA imaging at kiloparsec-scale resolution of sixteen core-dominated radio-loud QSOs is presented. Many objects appear to display variable radio emission and their radio morphologies are significantly smaller than those of steep-spectrum…

Astrophysics · Physics 2007-05-23 Peter D. Barthel , Marianne Vestergaard , Colin J. Lonsdale

We present VLBI observations, carried out with the European Very Long Baseline Interferometry Network (EVN), of SDSSJ143244.91+301435.3, a radio-loud narrow-line Seyfert 1 (RLNLS1) characterized by a steep radio spectrum. The source,…

High Energy Astrophysical Phenomena · Physics 2016-11-15 A. Caccianiga , D. Dallacasa , S. Anton , L. Ballo , M. Berton , K. -H. Mack , A. Paulino-Afonso

We present multiwaveband observations of a well selected sample of 28 quasars and two radio galaxies with flat radio spectra and strong millimeter wave emission (referred to here as FSRQ's). The observations include multifrequency VLBI…

We observed the gravitationally lensed blazar JVAS B0218+357 with the KVN and VERA Array (KaVA) at 22, 43, and 86 GHz. The source has recently been identified as an active gamma-ray source up to GeV/TeV energy bands, rendering a unique…

Astrophysics of Galaxies · Physics 2020-09-03 Kazuhiro Hada , Kotaro Niinuma , Julian Sitarek , Cristiana Spingola , Ayumi Hirano

The problem of phaseless aperture synthesis is of current interest in phase-unstable VLBI with a small number of elements when either the use of closure phases is not possible (a two-element interferometer) or their quality and number are…

Astrophysics · Physics 2009-11-10 Anisa T. Bajkova

We observed with the VLBA at 2.3 and 8.6 GHz a complete flux-density limited sample of 482 radio sources with declination >+75 degrees brighter than 200 mJy at 1.4 GHz drawn from the NVSS catalog. 34% of the sources show parsec-scale…

Astrophysics of Galaxies · Physics 2021-02-01 Alexander V. Popkov , Yuri Y. Kovalev , Leonid Y. Petrov , Yuri A. Kovalev

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 an analysis of the spectral properties of the extragalactic radio sources in the nearly-complete VSA sample at 33GHz. Data from different surveys are used to study source spectra between 1.4 and 33GHz. We find that, in general,…

We study the radio properties of moderately obscured quasars over a range of redshifts to understand the role of radio activity in accretion using the Jansky Very Large Array (JVLA) at 6.0GHz and 1.4GHz. Our z~2.5 sample consists of…

Astrophysics of Galaxies · Physics 2016-08-31 Rachael M. Alexandroff , Nadia L. Zakamska , Sjoert van Velzen , Jenny E. Greene , Michael A. Strauss

We present a new sample of 30 nearby (z<0.2) BL Lacs, selected to study the nuclear as well as the large scale properties of low power radio sources. In this first paper, we show and discuss new radio data taken with the VLA (19 objects at…

Astrophysics · Physics 2009-11-10 M. Giroletti , G. Giovannini , G. B. Taylor , R. Falomo

To study statistical properties of different classes of sources, it is necessary to observe a sample that is free of selection effects. To do this, we initiated a project to observe a complete sample of radio galaxies selected from the B2…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 E. Liuzzo , G. Giovannini , M. Giroletti , G. B. Taylor

We have selected a sample of 80 candidates for obscured radio-loud active galactic nuclei and presented their basic optical/near-infrared (NIR) properties in Paper 1. In this paper, we present both high-resolution radio continuum images for…

Astrophysics of Galaxies · Physics 2016-03-16 Ting Yan , John T. Stocke , Jeremy Darling , Emmanuel Momjian , Soniya Sharma , Nissim Kanekar

We report 1.7 GHz Very Long Baseline Interferometry (VLBI) observations of IRAS F10214+4724, a lensed z=2.3 obscured quasar with prodigious star formation. We detect what we argue to be the obscured active nucleus with an effective angular…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 R. P. Deane , S. Rawlings , M. A. Garrett , I. Heywood , M. J. Jarvis , H. -R. Klöckner , P. J. Marshall , J. P. McKean

The powerful high-redshift quasar J2102+6015 (at z=4.575) may provide useful information for studying supermassive black hole growth, galaxy evolution and feedback in the early Universe. The source has so far been imaged with very long…

Astrophysics of Galaxies · Physics 2023-03-20 S. Frey , T. An , K. Gabányi , L. Gurvits , M. Krezinger , A. Melnikov , P. Mohan , Z. Paragi , K. Perger , F. Shu , O. Titov , P. de Vicente , Y. Zhang