相关论文: Samples and statistics of CSS and GPS sources

The measurement of proper motions in CSOs is a powerful tool to determine the dynamical evolution of the newly born extragalactic radio sources. We observed 3 CSOs with the VLBA in 2004 and in 2006 to monitor changes in their structure and…

We present radio observations of 19 candidate compact steep-spectrum (CSS) objects selected from a well-defined, complete sample of 52 B2 radio sources of intermediate strength. These observations were made with the VLA A-array at 4.835…

Gigahertz Peaked Spectrum (GPS) sources and Compact Symmetric Objects (CSO) are selected in very different ways, but have a significant overlap in properties. Ever since their discovery it has been speculated that they are young objects,…

The compact steep spectrum (CSS) and gigahertz peaked spectrum (GPS) sources are widely believed to be young radiosources, with ages <10^6 yr. If the activity in the nucleus is fuelled by the supply of gas, one might find evidence of this…

We define a complete sample of thirty-three GHz-Peaked-Spectrum (GPS) radio sources based on their spectral properties. We present measurements of the radio spectra and polarization of the complete sample and a list of additional GPS…

From 43GHz VLBA observations of the pair of radio sources 1928+738 and 2007+777 we have demonstrated the feasibility of precision phase-delay differential astrometric techniques at millimeter wavelengths. For a pair of sources with 5…

Multifrequency VLBA observations of the final group of ten objects in a sample of FIRST-based compact steep spectrum (CSS) sources are presented. The sample was selected to investigate whether objects of this kind could be relics of…

We investigate the relation between the Doppler factor determined from variations in total flux at 22 and 37 GHz, and the apparent transverse velocity determined from VLBA observations at 2 cm. The data are consistent with the relativistic…

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…

Multifrequency observations with the GMRT and the VLA are used to determine the spectral breaks in consecutive strips along the lobes of a sample of selected giant radio sources (GRSs) in order to estimate their spectral ages. The maximum…

VLBA observations at 18 cm are presented for 28 Compact Steep-spectrum radio Sources (CSSs) from the B3-VLA CSS sample. These sources were unresolved in previous VLA observations at high frequencies or their brightness distribution was…

High-redshift radio-loud quasars are used to, among other things, test the predictions of cosmological models, set constraints on black hole growth in the early universe and understand galaxy evolution. Prior to this paper, 20 extragalactic…

We present first results from electronic Multi-Element Remotely Linked Interferometer Network (e-MERLIN) and electronic European VLBI Network (e-EVN) observations of a small sample of ultra-steep spectrum radio sources, defined as those…

We present results of EVN observations of eleven GHz-Peaked-Spectrum (GPS) radio sources at 2.3/8.4 GHz. These sources are from the classical ''bright'' GPS source samples with peak flux densities $>$ 0.2 Jy and spectral indices $\alpha <…

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…

We summarize results from flux density monitoring campaigns performed with the 100 meter radio-telescope at Effelsberg and the VLA during the past 15 yrs. We briefly discuss some of the statistical properties of the rapid variability from…

We present results on the intrinsic brightness temperature of a sample of compact radio sources observed at 86 GHz using the Global Millimeter VLBI Array. We use the observed brightness temperatures at 86 GHz and the observed superluminal…

Interplanetary scintillation (IPS) provides an approach for identifying the presence of sub-arcsec structures in radio sources, and very long baseline interferometry (VLBI) technique can help verify whether the IPS sources have fine…

Multifrequency Very Long Baseline Array (VLBA) observations were performed to study the radio morphology and the synchrotron spectra of four high frequency peaking radio sources. They are resolved in several compact components and the radio…

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…