相关论文: Using Radio Bubbles to Constrain the Matter Conten…
The matter content of jets in active galactic nuclei is examined in a new way. We model the dynamical expansion of its cocoon embedded in the intra-cluster medium (ICM). By comparing the observed shape of the cocoon with that expected from…
Relativistic jets of radio loud active galactic nuclei (AGN) produce highly directed, intense beams of radiation. A fraction of this beamed radiation scatters on the thermal plasma generally surrounding an AGN. The morphology of the…
Recent observations have allowed the geometry and kinematics of the M87 jet to be tightly constrained. We combine these constraints with historical Very Long Baseline Interferometry (VLBI) results and the theory of synchrotron self-absorbed…
AGN bubbles in cool-core galaxy clusters are believed to facilitate the transport of cosmic ray electrons (CRe) throughout the cluster. Recent radio observations are revealing complex morphologies of cluster diffuse emission, potentially…
Recent x-ray and radio data from radio sources in galaxy clusters are used to show that the pdV work required to inflate the radio lobes exceeds all other energy estimates deduced from the radio emission. If the required jet energy density…
Seyfert galaxies and quasars were first discovered through optical and radio techniques, but in recent years high-energy emission, that can penetrate central gas and dust, has become essentially the defining characteristic of an AGN. AGNs…
The synchrotron-radiating particles and magnetic fields in low-power radio galaxies (including most nearby cluster-centre sources), if at equipartition, can provide only a small fraction of the total internal energy density of the radio…
There is good evidence for X-ray emission associated with AGN jets which are relativistically boosted towards the observer. But to what jet radius does such X-ray emission persist? To attempt to answer this question one can look at radio…
Estimates of magnetic field strength in relativistic jets of active galactic nuclei (AGN), obtained by measuring the frequency-dependent radio core location, imply that the total magnetic fluxes in those jets are consistent with the…
The energy content of large-scale jets in FR I radio galaxies is still an open issue. Here we show that upper limits on the high-energy and very high-energy gamma-ray emission of the kpc-scale jet in M 87 radio galaxy imposed by EGRET,…
Quasars with flat radio spectra and one-sided, arc-second scale, ~100 mJy GHz radio jets are found to have similar scale X-ray jets in about 60% of such objects, even in short 5 to 10 ks Chandra observations. Jets emit in the GHz band via…
Gamma-ray emission from AGN provides us with unprecedented insights into the physics of extragalactic jets. The emission from these jets fits naturally into the existing theoretical framework of relativistic jets as inferred from parsec…
Active galactic nucleus (AGN) powered jets can accelerate cosmic ray electrons, leading to the observed radio synchrotron emission. To simulate this emission, jet dynamics in galaxy clusters must be coupled to electron spectral modelling.…
In this paper I review the results of our ongoing project to investigate the coupling between accretion disk and radio jet in galactic nuclei and stellar mass black holes. We find a good correlation between the UV bump luminosity and the…
While observations in the radio band are providing essential information on the innermost structures of relativistic jets in active galactic nuclei (AGN), the recent detection by Fermi of gamma-ray emission from many hundreds of blazars…
We explore energy densities of magnetic field and relativistic electrons in the M87 jet. Since the radio core at the jet base is identical to the optically thick surface against synchrotron self absorption (SSA), the observing frequency is…
The composition and energy dissipation in jets are two of the fundamental questions of jet physics that are not fully understood. In this paper, we attempt to constrain the composition, magnetization as well as radiative efficiency for…
Motivated by the large number of jets detected by the Chandra X-ray Observatory, and by the inverse Compton X-ray emission model (IC/CMB) for relativistic jets, we revisit two basic questions: ``If the medium that carries the jet's energy…
This paper summarizes some of our recent projects which try to illuminate the nature and importance of jets associated with active nuclei and compact objects. After a short introduction on jets in radio galaxies and radio loud quasars the…
We discuss the physical properties of four quasar jets imaged with the Chandra X-ray Observatory in the course of a survey for X-ray emission from radio jets. These objects have sufficient counts to study their spatially resolved…