相关论文: High-redshift radio galaxies: at the crossroads

The energy emitted by active galactic nuclei (AGN) may provide a self-regulating process (AGN feedback) that shapes the evolution of galaxies. This is believed to operate along two modes: on galactic scales by clearing the interstellar…

Jet precession is sometimes invoked to explain asymmetries in radio galaxy (RG) jets and "X/S/Z-shape" radio galaxies, caused by the presence of a binary black hole companion to the source active galactic nucleus (AGN) or by accretion…

How well is the modern-day starburst-AGN connection mirrored in the early Universe? This is starting to be answered by deep wide radio surveys such as ATLAS, which are giving us a new view of high redshift galaxies. For example, we find…

We briefly review X-ray studies of ionized AGN outflows and high-redshift AGN. We discuss recent progress with Chandra and XMM-Newton as well as prospects and requirements for future X-ray missions.

We use the K-z relation for radio galaxies to illustrate why it has proved difficult to obtain definitive cosmological results from studies based entirely on catalogues of the brightest radio sources, e.g. 3C. To improve on this situation…

Combined investigations of the clustering properties of galaxies of different spectral type and high-redshift quasars strongly suggest local ellipticals to be the parent population of optically bright Active Galactic Nuclei (AGN). However,…

High redshift radio galaxies are great cosmological tools for pinpointing the most massive objects in the early Universe: massive forming galaxies, active super--massive black holes and proto--clusters. We report on deep narrow--band…

Active Galactic Nuclei (AGN) are remarkable astronomical sources emitting over the whole electromagnetic spectrum, with different bands providing unique windows on distinct sub-structures and their related physics. AGN come in a large…

Some of the radio galaxies show distortion in their jets, forming tailed or winged sources. X-shaped radio galaxies are a subclass of winged sources formation mechanism of which is still unclear. The focus of this work is to understand…

Using a sample of 2922 z<0.2, spectroscopically-identified Active Galactic Nuclei (AGN) we explore the relationship between radio size and the prevalence of extreme ionised outflows, as traced using broad [O III] emission-line profiles in…

We present 1-7 GHz high-resolution radio imaging (VLA and e-MERLIN) and spatially-resolved ionized gas kinematics for ten z<0.2 type~2 `obscured' quasars (log [L(AGN)/(erg/s)]>~45) with moderate radio luminosities (log…

Active galactic nuclei (AGNs) form two distinct sequences on the radio-loudness -- Eddington-ratio plane. The `upper' sequence contains radio selected AGNs, the `lower' sequence is composed mainly of optically selected AGNs. The sequences…

Active galaxies are the most powerful engines in the Universe for converting gravitational energy into radiation, and radio galaxies and radio-loud quasars are highly luminous and can be detected across the Universe. The jets that…

I review some recent cosmological studies based on redshift surveys of radio sources selected at low frequencies. The accretion rate onto the central black hole is identified as the basis of a crude physical division of the low-frequency…

The low-frequency radio sky is dominated by the diffuse synchrotron emission of our Galaxy and extragalactic radio sources related to Active Galactic Nuclei and star-forming galaxies. This foreground emission is much brighter than the…

Transient astronomical sources are typically powered by compact objects and usually signify highly explosive or dynamic events. While radio astronomy has an impressive record of obtaining high time resolution observations, usually it is…

I briefly review the current status of observations of AGN-powered UV/optical light, starlight, dust and outflow phenomena in high-redshift powerful radio galaxies. The existing data are consistent with the hypothesis that powerful radio…

In order to identify the dominant nuclear outflow mechanisms in Active Galactic Nuclei, we have undertaken deep, high resolution observations of two compact radio sources (PKS 1549-79 and PKS 1345+12) with the Advanced Camera for Surveys…

High redshift radio galaxies are among the largest, most luminous, most massive, and most beautiful objects in the Universe. They are generally identified from their radio emission, thought to be powered by accretion of matter onto…

It has recently become apparent that the background level of diffuse radio emission on the sky is significantly higher than the level that can result from known extragalactic radio source classes or our Galaxy given our current…