相关论文: High-redshift radio galaxies: at the crossroads
Considerable asymmetries in jets from active galactic nuclei (AGN) and associated double radio sources can be caused by an inhomogeneous interstellar medium of the host galaxy. These asymmetries can easily be estimated by 1D propagation…
We present Chandra X-ray observations of the powerful radio galaxy 3C171, which reveal an extended region of X-ray emission spatially associated with the well-known 10-kpc scale optical emission-line region around the radio jets. We argue…
New challenges in the modelling of galaxy spectra are bound to emerge as upcoming telescopes like the James Webb Space Telescope will allow us to detect galaxies at fainter flux levels and higher redshifts than ever before. Here, we…
Updates are provided on several issues related to Unified Models. A new HST spectrum of Cygnus A confirms the broad MgII emission line, and suggests a very large velocity width as seen in the polarized optical lines. Statistics of the 3CR…
The nearby radio galaxy 3C293 is one of a small group of objects where extreme outflows of neutral hydrogen have been detected. However, due to the limited spatial resolution of previous observations, the exact location of the outflow was…
By combining the 2-degree Field Galaxy Redshift Survey with the NRAO VLA Sky Survey at 1.4 GHz, the environments of radio loud AGN in the nearby Universe are investigated using both local projected galaxy densities and a friends-of-friends…
AGN activity is known to drive fast outflows of gas. We report the discovery of fast outflows of neutral gas with velocities over 1000 km/s in a number of radio galaxies. In the best studied object, 3C~293, the kinematical properties of the…
Extreme Scattering Events are sometimes manifest in the light-curves of compact radio-quasars at frequencies of a few GHz. These events are not understood. The model which appears to offer the best explanation requires a new population of…
IC883 is a luminous infrared galaxy (LIRG) classified as a starburst-active galactic nucleus (AGN) composite. In a previous study we detected a low-luminosity AGN (LLAGN) radio candidate. Here we report on our radio follow-up at three…
We present our very recent results on the sub-mJy radio source populations at 1.4 GHz based on the Extended Chandra Deep Field South VLA survey, which reaches ~ 30 {\mu}Jy, with details on their number counts, evolution, and luminosity…
This article gives a brief historical introduction and reviews our current understanding of jets in radio galaxies and quasars from an observational perspective, with an emphasis on observations at radio wavelengths. Recent results on the…
Over the last five decades, AGN studies have produced a number of spectacular examples of synergies and multifaceted approaches in astrophysics. The field of AGN research now spans the entire spectral range and covers more than twelve…
I present simple but robust estimates of the types of sources making up the faint, sub-microJy radio sky. These include, not surprisingly, star-forming galaxies and radio-quiet AGN but also two "new" populations, that is low radio power…
Gigahertz Peaked Spectrum (GPS) radio galaxies are generally thought to be the young counterparts of classical extended radio sources and live in massive ellipticals. GPS sources are vital for studying the early evolution of radio-loud AGN,…
Various observational techniques have been used to survey galaxies and AGN, from X-rays to radio frequencies, both photometric and spectroscopic. I will review these techniques aimed at the study of galaxy evolution and of the role of AGNs…
The discovery of cosmic radio emission by Karl Jansky in the course of searching for the source of interference to telephone communications and the instrumental advances which followed, have led to a series of new paradigm changing…
Determination of the epoch dependent star-formation rate of field galaxies is one of the principal goals of modern observational cosmology. Deep radio surveys, sensitive to starbursts out to $z \sim$ 1-2, may hold the key to understanding…
From an optical spectroscopic survey of 3CR radiogalaxies (RGs) with z<0.3, we discovered three objects characterized by an extremely low level of gas excitation and a large deficit of line emission with respect to RGs of similar radio…
We show that the winds identified with high-redshift low-mass galaxies may strongly affect the formation of stars in more massive galaxies that form later. With 3D realizations of a simple linear growth model we track gas shocking, metal…
Rotating and oscillating neutron stars can give rise to long-lived Continuous Gravitational Waves (CGWs). Despite many years of searching, the detection of such a CGW signal remains elusive. In this article we describe the main…