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

200 papers

We present a comprehensive multi-frequency catalogue of radio sources behind the Large Magellanic Cloud between 0.2 and 20 GHz, gathered from a combination of new and legacy radio continuum surveys. This catalogue covers an area of…

We have explored, in the general framework of the ``young source'' scenario, evolutionary models for GHz Peaked Spectrum (GPS) galaxies and quasars which reproduce the observed counts, redshift and peak frequency distributions of currently…

Astrophysics · Physics 2007-05-23 G. De Zotti , G. L. Granato , L. Silva , D. Maino , L. Danese

We report on sensitive radio observations made with the VLA at 8.5 GHz, centered on the Hubble Deep Field (HDF). We collected data in the A, CnB, C, DnC, and D configurations, corresponding to angular resolutions ranging from 0.3" to 10".…

Using the JVLA, we explored the Galactic center (GC) with a resolution of 0.05" at 33.0 and 44.6 GHz. We detected 64 hyper-compact radio sources (HCRs) in the central parsec. The dense group of HCRs can be divided into three spectral types:…

Astrophysics of Galaxies · Physics 2022-03-09 Jun-Hui Zhao , Mark R. Morris , W. M. Goss

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 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…

Compact Steep Spectrum, Gigahertz Peaked Spectrum and High Frequency Peak (CSS, GPS, HFP) sources are considered to be young radio sources but the details of their duty cycle are not well understood. In some cases they are thought to…

Astrophysics of Galaxies · Physics 2016-12-07 M. Brienza , R. Morganti , A. Shulevski , L. Godfrey , N. Vilchez

A complete, flux density limited sample of 96 faint ($> 0.5$ mJy) radio sources is selected from the 10C survey at 15.7 GHz in the Lockman Hole. We have matched this sample to a range of multi-wavelength catalogues, including SERVS, SWIRE,…

Astrophysics of Galaxies · Physics 2015-09-30 I. H. Whittam , J. M. Riley , D. A. Green , M. J. Jarvis , M. Vaccari

We report the radio continuum properties for several samples of peaked spectrum (PS) radio sources. Broadband spectra of the objects were analysed using the RATAN-600 six-frequency (1.2-22 GHz) observations and available literature data,…

Astrophysics of Galaxies · Physics 2021-11-10 Yu. Sotnikova , T. Mufakharov , M. Mingaliev , A. Mikhailov

I extract the radio spectral index, $\alpha$, from 541,195 common sources observed in the 150 MHz TIFR GMRT Sky Survey (TGSS) and the 1.4 GHz NRAO VLA Sky Survey (NVSS). This large common source catalogue covers about $80\%$ of the sky. The…

Astrophysics of Galaxies · Physics 2019-07-26 Prabhakar Tiwari

A complete sample of 96 faint ($S > 0.5$ mJy) radio galaxies is selected from the Tenth Cambridge (10C) survey at 15.7~GHz. Optical spectra are used to classify 17 of the sources as high-excitation or low-excitation radio galaxies (HERGs…

Astrophysics of Galaxies · Physics 2016-08-31 Imogen H. Whittam , Julia M. Riley , David A. Green , Matt J. Jarvis

We present Karl G. Jansky Very Large Array (VLA) S- (2--4 GHz), C- (4--8 GHz), and X-band (8--12 GHz) continuum observations toward seven radio-loud quasars at $z>5$. This sample has previously been found to exhibit spectral peaks at…

In this paper we present follow-up optical observations of Ultra Steep Spectrum sources that were found by matching 150 MHz GMRT sources with either the 74 MHz VLSS or the 1400 MHz NVSS. These sources are possibly high-redshift radio…

Cosmology and Nongalactic Astrophysics · Physics 2011-10-12 Samuel J. George , Ian R. Stevens

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 report here the study, in the radio band, of a sample of candidates of high Rotation Measure (RM). The point-like objects (at kpc scale) were selected by choosing unpolarised sources from the NVSS which show significant linear…

Astrophysics of Galaxies · Physics 2016-03-16 Alice Pasetto , Alex Kraus , Karl-Heinz Mack , Gabriele Bruni , Carlos Carrasco-Gonzalez

The peaked-spectrum (PS) sources exhibit turnover characteristics in their broad radio spectra. However, the mechanism underlying this phenomenon remains elusive. The two most common hypotheses are synchrotron self-absorption (SSA) and…

Astrophysics of Galaxies · Physics 2025-05-26 Guang-Chen Sun , Yichao Li , Furen Deng , Yanping Cong , Fangxia An , Jiajun Zhang , Yougang Wang , Xin Zhang , Xuelei Chen

We present optical identifications and redshifts for seventeen new high-redshift radio sources. Fifteen of these sources are radio galaxies; the remaining two are high-redshift, steep-spectrum, radio-loud quasars. These objects were…

Ultra-steep spectrum (USS) radio sources are good tracers of powerful radio galaxies at $z > 2$. Identification of even a single bright radio galaxy at $z > 6$ can be used to detect redshifted 21cm absorption due to neutral hydrogen in the…

Astrophysics of Galaxies · Physics 2018-01-31 A. Saxena , P. Jagannathan , H. J. A. Röttgering , P. N. Best , H. T. Intema , M. Zhang , K. J. Duncan , C. L. Carilli , G. K. Miley

We present the results of 5-GHz observations with the VLA A-array of a sample of candidate Compact Steep Spectrum sources (CSSs) selected from the S4 survey. We also estimate the symmetry parameters of high-luminosity CSSs selected from…

Astrophysics · Physics 2009-10-31 D. J. Saikia , S. Jeyakumar , C. J. Salter , P. Thomasson , R. E. Spencer , F. Mantovani

We present optical spectroscopy of 62 objects selected from several samples of ultra steep spectrum (USS) radio sources. 46 of these are from our primary catalog, consisting of 669 sources with radio spectral indices alpha < -1.30 (S_nu ~…