相关论文: Young Extragalactic Radio Sources

The knowledge of physical conditions in young radio sources is important for defining the framework of models describing radio source evolution. We investigate whether young radio sources are in equipartition (i.e. minimum energy)…

Compact Symmetric Objects (CSO) are considered to be the young version of Fanaroff-Riley type I and type II radio galaxies, with typical sizes smaller than 1 kpc and ages of the order of a few thousand years. Before the launch of the Fermi…

Recent sensitive wide-field radio surveys, such as the LOFAR Two Meter Sky Survey (LoTSS), the LOFAR LBA Sky Survey (LoLSS), and the Very Large Array Sky Survey (VLASS), enable the selection of statistically large samples of peaked-spectrum…

There is mounting evidence that mechanical radio source feedback is important in galaxy evolution and in order to quantify this feedback, detailed models of radio source evolution are required. We present an extension to current analytic…

Compact symmetric objects (CSOs) are thought to be short-lived radio sources with two lobes of emission that are separated by less than a kpc in projection. However, studies of such systems at high redshift is challenging due to the limited…

In order to understand the origin and evolution of radio galaxies, searches for the youngest such sources have been conducted. Compact-medium symmetric objects (CSO-MSOs) are thought to be the earliest stages of radio sources, with possible…

The Gigahertz Peaked Spectrum (GPS) sources, Compact Steep Spectrum (CSS) radio sources, and High Frequency Peakers (HFP) radio sources are thought to be young radio AGNs, at the early stage of AGN evolution. We investigated the optical…

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…

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…

We present radio images of two giant quasars from the Molonglo/1Jy sample, and make a comparative study of giant radio sources selected from the literature with 3CR radio sources of smaller sizes to investigate the evolution of giant…

There is quite a clear anticorrelation between the intrinsic peak frequency and the overall radio source size in Compact Steep Spectrum (CSS) and GHz Peaked Spectrum (GPS) radio sources as shown by O'Dea (1998). This feature is interpreted…

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…

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.…

We report the results of multifrequency-VLBI observations of GHz-Peaked-Spectrum (GPS) radio sources. The VLBI structure and component spectra of some GPS sources are presented. Our VLBI results show that about 80% of the GPS galaxies…

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…

Based on the FIRST and SDSS catalogues a flux density limited sample of weak Compact Steep Spectrum (CSS) sources with radio luminosity below 10^26 [W/Hz] at 1.4 GHz has been constructed. Our previous multifrequency observations of CSS…

Observations of ten Compact Symmetric Objects ({\rm CSO}) candidates have been made with the Very Long Baseline Array at 8.4 GHz in 2005 and with a combined Chinese and European VLBI array at 8.4 GHz in 2009. The 2009 observations…

Compact Steep Spectrum (CSS) and Gigahertz Peaked Spectrum (GPS) sources are classes of compact, powerful, extragalactic objects. These sources are thought to be the earliest stages in the evolution of radio galaxies, capturing the ignition…

We review the statistical properties of the main populations of radio sources, as emerging from radio and millimeter sky surveys. Recent determinations of local luminosity functions are presented and compared with earlier estimates still in…

We present results of multifrequency polarimetric VLBA observations of 34 compact radio sources. The observations are part of a large survey undertaken to identify CSOs Observed in the Northern Sky (COINS). Compact Symmetric Objects (CSOs)…