Related papers: Structure, spectra and variability of some GPS rad…
We present VLBA observations at 15 GHz of ten GHz Peaked Spectrum (GPS) radio sources. The cores are often difficult or impossible to locate. When likely cores are found, they account for a small fraction of the flux density in GPS galaxies…
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…
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…
We present the data and analysis of VLBI observations at 1.6, 5 and 15 GHz of a sample of faint Gigahertz Peaked Spectrum (GPS) sources selected from the Westerbork Northern Sky Survey (WENSS). The 5 GHz observations involved a global array…
We defined a sub-sample of twelve GPS sources which have not been observed with the VLBI before, from the Parkes half-Jansky sample, and carried out VLBI observations at 1.6 GHz and 5 GHz with the European VLBI Network (EVN) in 2006 and…
Aims and Methods: We present the results of VLBI observations of nineteen GHz-Peaked-Spectrum (GPS) radio sources at 1.6 GHz. Of them, 15 sources are selected from the Parkes Half Jansky (PHJ) sample (Snellen 2002), 4 others are from our…
We discuss the morphology and kinematics of five gigahertz-peaked spectrum (GPS) sources that have been observed with the VLBA. We find a wide range of observed properties including core-jet structure, superluminal motion, variability,…
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…
We present the results of EVN polarization observations of fourteen GHz-Peaked-Spectrum (GPS) radio sources at 5 GHz. These sources were selected from bright GPS source samples and we aimed at finding Compact Symmetric Objects (CSOs). We…
Data from a recent Australia Telescope Compact Array (ATCA) program of multi-frequency, multi-epoch monitoring of 202 active galactic nuclei with declinations < +10 degrees have been searched for GHz Peaked Spectrum (GPS) and Compact Steep…
A sample of 47 faint Gigahertz Peaked Spectrum (GPS) radio sources selected from the Westerbork Northern Sky Survey (WENSS, Rengelink et al. 1997), has been imaged in the optical and near infrared, resulting in an identification fraction of…
Many low-luminosity active galactic nuclei (AGNs) contain a compact radio core which can be observed with high angular resolution using very long baseline interferometry (VLBI). Combining arcsec-scale structural information with…
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…
Multi-frequency, multi-epoch ATCA observations of a sample of AGN resulted in the identification of 9 new candidate Giga-hertz Peaked Spectrum (GPS) sources. Here we present Long Baseline Array observations at 4.8 GHz of the four candidates…
Monitoring results are presented for the Stangellini 1 Jy GHz-peaked-spectrum source sample, illustrating that several members exhibit variability in total flux and/or linear polarization over timescales of order a decade. The variability…
Global VLBI observations at 5 GHz have been performed to study the source morphology in 10 compact steep-spectrum (CSS) sources selected from the Peacock & Wall catalogue with the aim of finding asymmetric structures produced by the…
A relativistic radio component, which moves in a direction close to the sky plane, will increase in flux density when it decelerates. This effect is the basis for the qualitative model for GPS galaxies we present in this paper, which can…
Gigahertz-Peaked spectrum (GPS) sources are compact active galactic nuclei, presumably young precursors of bright radio sources. The study of GPS radio properties provides information about the features of synchrotron radiation in…
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 compact radio source Sgr\,A*, associated with the super massive black hole at the center of the Galaxy, has been studied with VLBA observations at 3 frequencies (22, 43, 86\,GHz) performed on 10 consecutive days in May 2007. The total…