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According to a generally accepted paradigm, small intrinsic sizes of Compact Steep Spectrum (CSS) radio sources are a direct consequence of their youth, but in later stages of their evolution they are believed to become large-scale sources. However, this notion was established mainly for strong CSS sources. In this series of papers we test this paradigm on 60 weaker objects selected from the VLA FIRST survey. They have 5-GHz flux densities in the range 150 < S_{5GHz} < 550 mJy and steep spectra in the range 0.365 le u le 5 GHz. The present paper is focused on sources that fulfill the above criteria and have angular sizes in the range 0.2arcsec - 1arcsec. Observations of 19 such sources were obtained using MERLIN in snapshot mode at 5 GHz. They are presented along with 1.7-GHz VLBA and 5-GHz EVN follow-up snapshot observations made for the majority of them. For one of the sources in this subsample, 1123+340, a full-track 5-GHz EVN observation was also carried out. This study provides an important element to the standard theory of CSS sources, namely that in a number of them the activity of their host galaxies probably switched off quite recently and their further growth has been stopped because of that. In the case of 1123+340, the relic of a compact dead source is particularly well preserved by the presence of intracluster medium of the putative cluster of galaxies surrounding it. The observed overabundance of compact sources can readily be explained in the framework of the scenario of premature cessation of the activity of the host galaxy nucleus. It could also explain the relatively low radio flux densities of many such sources and, in a few cases, their peculiar, asymmetric morphologies. We propose a new interpretation of such asymmetries based on the light-travel time argument.
A new sample of candidate Compact Steep Spectrum (CSS) sources that are much weaker than the CSS source prototypes has been selected from the VLA FIRST catalogue. MERLIN `snapshot observations of the sources at 5 GHz indicate that six of them have an
Evidence has been mounting recently that activity in some radio-loud AGNs (RLAGNs) can cease shortly after ignition and that perhaps even a majority of very compact sources may be short-lived phenomena because of a lack of stable fuelling from the bl
We report first X-ray Chandra observations of a sample of seven low luminosity compact (LLC) sources. They belong to a class of young compact steep spectrum (CSS) radio sources. Four of them have been detected, the other three have upper limit estima
Compact steep-spectrum (CSS) and peaked spectrum (PS) radio sources are compact, powerful radio sources. The multi-frequency observational properties and current theories are reviewed with emphasis on developments since the earlier review of ODea (19
We present Very Long Baseline Interferometry observations of a faint and low-luminosity ($L_{rm 1.4 GHz} < 10^{27}~mbox{W Hz}^{-1}$) Gigahertz-Peaked Spectrum (GPS) and Compact Steep Spectrum (CSS) sample. We select eight sources from deep radio obse