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Related papers: High frequency peakers. I. The bright sample

200 papers

This paper analyses the radio properties of a subsample of optically obscured (R>25.5) galaxies observed at 24um by the Spitzer Space Telescope within the First Look Survey. 96 F[24um]>0.35 mJy objects out of 510 are found to have a radio…

Astrophysics · Physics 2009-11-13 M. Magliocchetti , P. Andreani , M. A. Zwaan

It has been known for nearly three decades that high redshift radio galaxies exhibit steep radio spectra, and hence ultra-steep spectrum radio sources provide candidates for high-redshift radio galaxies. Nearly all radio galaxies with z > 3…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 C. H. Ishwara-Chandra , S. K. Sirothia , Y. Wadadekar , S. Pal , R. Windhorst

We present Very Large Array observations at 1.4 and 5 GHz of a sample of 16 quasi-stellar objects (QSOs) at z = 1.78 to 2.71. Half of the chosen quasars are bright at mm wavelengths (250 or 350 GHz) while the other half were not detected at…

Astrophysics · Physics 2008-11-26 A. Petric , C. L. Carilli , F. Bertoldi , A. Beelen , P. Cox , A. Omont

We present follow-up observations at 5, 8 and 30 GHz of the K-band Northern Wide Survey (KNoWS) 20 GHz Bright Sample, performed with the 32-m Medicina Radio Telescope and the 32-m Torun Radio Telescope. The KNoWS sources were selected in…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 R. Ricci , S. Righini , R. Verma , I. Prandoni , E. Carretti , K. -H. Mack , M. Massardi , P. Procopio , A. Zanichelli , L. Gregorini , F. Mantovani , M. P. Gawronski , M. W. Peel

High red-shift radio galaxies are best searched at low radio frequencies, due to its steep radio spectra. Here we present preliminary results from our programme to search for high red-shift radio galaxies to ~ 10 to 100 times fainter than…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Susanta Kumar Bisoi , C. H. Ishwara-Chandra , S. K. Sirothia , P. Janardhan

GHz-peaked spectrum (GPS) radio sources are thought to be young objects which later evolve into FR-I and FR-II radio galaxies. We have used the Australia Telescope 20GHz (AT20G) survey catalogue to select a uniform sample of GPS sources…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Paul J. Hancock , Steven J. Tingay , Elaine M. Sadler , Chris Phillips , Adam T. Deller

We present initial results from a follow-up of the 9C survey, complete to 25 mJy at 15 GHz, designed to assemble and investigate a sample of young radiosources. We have made radio continuum maps of 111 sources at frequencies spanning 1.4-43…

We have used the upgraded Giant Metrewave Radio Telescope to map the Coma cluster of galaxies at 250-500 MHz and 1050-1450 MHz bands. These 6.26 arcsec and 2.18 arcsec resolutions observations allow detailed radio structures to be…

Astrophysics of Galaxies · Physics 2021-06-01 Dharam V. Lal

We present a 74 MHz survey of a 165 square degree region located near the north galactic pole. This survey has an unprecedented combination of both resolution (25'' FWHM) and sensitivity (RMS noise as low as 24 mJy/beam). We detect 949…

Astrophysics · Physics 2009-11-10 A. S. Cohen , H. J. A. Rottgering , M. J. Jarvis , N. E. Kassim , T. J. W. Lazio

We started a follow-up investigation of the Deep X-ray Radio Blazar Survey objects with declination >-10 deg. We undertook a survey with the EVN at 5GHz to make the first images of a complete sample of weak blazars, aiming at a comparison…

Astrophysics of Galaxies · Physics 2015-04-29 F. Mantovani , M. Bondi , K. -H. Mack , W. Alef , E. Ros , J. A. Zensus

We investigate the sample of 213 GPS sources selected from simultaneous multi-frequency 1-22 GHz observations obtained with RATAN-600 radio telescope. We use publicly available data to characterize parsec-scale structure of the selected…

Astrophysics of Galaxies · Physics 2009-01-23 K. V. Sokolovsky , Y. Y. Kovalev

In this work, we study the optical properties of compact radio sources selected from the literature in order to determine the impact of the radio-jet in their circumnuclear environment. Our sample includes 58 Compact Steep Spectrum (CSS)…

We present {\it Chandra} X-ray Observatory observations of Giga-Hertz Peaked Spectrum (GPS) and Compact Steep Spectrum (CSS) radio sources. The {\it Chandra} sample contains 13 quasars and 3 galaxies with measured 2-10 keV X-ray luminosity…

We are entering a new era of sensitive, large-area and multi-frequency radio surveys that will allow us to identify Gigahertz-Peaked Spectrum (GPS) and Compact Steep Spectrum (CSS) radio sources over a wide range in radio luminosity and…

Astrophysics of Galaxies · Physics 2016-03-16 Elaine M. Sadler

With the goal of identifying high redshift radio galaxies with FRI classification, here are presented high resolution, wide-field radio observations, near infra-red and optical imaging and multi-object spectroscopy of two fields of the…

Astrophysics · Physics 2009-11-13 E. E. Rigby , I. A. Snellen , P. N. Best

Recent studies have shown that both 21cm HI absorption and soft X-ray absorption serve as excellent tracers of the dense and dusty gas near the active nucleus of young radio galaxies, offering new insight into the physical nature of the…

Astrophysics of Galaxies · Physics 2022-01-05 Emily F. Kerrison , Vanessa A. Moss , Elaine M. Sadler , James R. Allison

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 present a study of the radio variability of bright, $S_{1.4}\geq100$ mJy, high-redshift quasars at $z\geq3$ on timescales up to 30-40 years. The study involved simultaneous RATAN-600 measurements at frequencies of 2.3, 4.7, 8.2, 11.2,…

The 100-m Robert C. Byrd Green Bank Telescope (GBT) and the Owens Valley Radio Observatory (OVRO) 40-m radio telescope have been used to conduct a survey of 3165 known extragalactic radio sources over 143 square degrees of the sky. Target…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-11 B. S. Mason , L. C. Weintraub , J. L. Sievers , J. R. Bond , S. T. Myers , T. J. Pearson , A. C. S. Readhead , M. C. Shepherd

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…

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