相关论文: Understanding Jets from Sources Straddling the Fan…
We observed 17 nearby low luminosity FR I radio galaxies using the NRAO Very Long Baseline Array (VLBA) at 1.67 GHz, as part of a multi-wavelength study of a complete sample of 21 sources selected by radio flux density from the Uppsala…
Relativistic jets are a common feature of radio loud active galactic nuclei. Multifrequency observations are a unique tool to constrain their physics. We report on a detailed study of the properties of the jet of the nearby BL Lac object…
We present the source structure analysis of 11 calibrator sources in the Southern Hemisphere at 2.3 (S-band) and 8.4 GHz (X-band). We used multi-epoch very long baseline interferometry source maps available in the radio fundamental catalog…
Observations of positional offsets between the location of X-ray and radio features in many resolved, extragalactic jets indicates that the emitting regions are not co-spatial, an important piece of evidence in the debate over the origin of…
There is substantial observational evidence against the symmetric relativistic model of FRII radio sources. An asymmetric relativistic model is proposed which takes account of both relativistic effects and intrinsic/environmental…
A small number of double-lobed radio galaxies (17 from our own census of the literature) show an additional pair of low surface brightness `wings', thus forming an overall `X'-shaped appearance. The origin of the wings in these radio…
The radiative and jet power in active galactic nuclei is generated by accretion of material on to supermassive galactic-centre black holes. For quasars, where the radiative power is by definition very high, objects with high radio…
The 2Jy sample is a survey of radio galaxies with flux densities above 2 Jy at 2.7 GHz. As part of our ongoing work on the southern subset of 2Jy sources, in paper I of this series we analysed the X-ray cores of the complete 2Jy sample with…
We present 3-D MHD and synthetic numerical simulations to follow the evolution of randomly magnetized intra-cluster medium plasma under the effects of powerful, light, hypersonic and bipolar jets. We prescribe the cluster magnetic field…
We argue that the origin of "FRI/FRI{-.1em}I dichotomy" -- the division between Fanaroff-Riley class I (FRI) with subsonic lobes and class I{-.1em}I (FRI{-.1em}I) radio sources with supersonic lobes is sharp in the radio-optical luminosity…
Many of the compact extragalactic radio sources that are used as fiducial points to define the celestial reference frame are known to have proper motions detectable with long-term geodetic/astrometric Very Long Baseline Interferometry…
The termination structures of the jets of Fanaroff & Riley galaxies are observed to produce extended non-thermal emission in a wide frequency range. The study of these structures can provide valuable insights on the conditions for particle…
We present five epochs of simultaneous radio (VLA) and X-ray (Chandra) observations of SS 433, to study the relation between the radio and X-ray emission in the arcsecond-scale jets of the source. We detected X-ray emission from the…
We present X-ray observations of the nuclear region of 25 Fanaroff-Riley I radio galaxies from the 3CRR and B2 catalogs, using data from the Chandra and XMM archives. We find the presence of a X-ray Central Compact Core (CCCX) in 13/25…
We analyze Chandra X-ray images of a sample of 11 quasars that are known to contain kiloparsec scale radio jets. The sample consists of five high-redshift (z >= 3.6) flat-spectrum radio quasars, and six intermediate redshift (2.1 < z < 2.9)…
Using new deep VLA and HST observations of the large-scale jet in 3C273 matched to 0.3" resolution, we have detected excess near-ultraviolet emission (300 nm) above a synchrotron cutoff spectrum accounting for the emission from radio…
The triple radio source detected in association with the luminous infrared source IRAS 16547-4247 has previously been studied with high angular resolution and high sensitivity with the Very Large Array (VLA) at 3.6-cm wavelength. In this…
We present spectral results, from Chandra and XMM-Newton observations, of a sample of 22 low-redshift (z < 0.1) radio galaxies, and consider whether the core emission originates from the base of a relativistic jet, an accretion flow, or…
Fanaroff-Riley II low-excitation radio galaxies (FRII-LERGs) are characterized by weak nuclear excitation on pc-scales and by properties typical of powerful FRIIs (defined as high-excitation, hereafter HERGs/BLRGs) on kp-scales. Since a…
We present results from Chandra X-ray imaging and spectroscopy of a flux-limited sample of flat spectrum radio-emitting quasars with jet-like extended structure. Twelve of twenty quasar jets are detected in 5 ks ACIS-S exposures. The…