Related papers: Imaging a Jet Base - Prospects with M87
The formation of jets in black hole accretion systems is a long-standing problem. It has been proposed that a jet can be formed by extracting the rotation energy of the black hole ("BZ-jet") or the accretion flow ("disk-jet"). While both…
The Fermi and Swift satellites, together with ground based Cherenkov telescopes, has greatly improved our knowledge of blazars, namely Flat Spectrum Radio Quasars and BL Lac objects, since all but the most powerful emit most of their…
We summarize HST observations of the M87 jet, concentrating on polarimetry and spectral index maps, and compare its optical and radio structures. The evidence now supports a stratified model for the structure of the jet, whereby…
AGN-launched jets are a crucial element in the study of supermassive black holes (SMBH) and their closest surroundings. The formation of such jets, whether they are launched by magnetic field lines anchored to the accretion disc or directly…
The concept of a new space very long baseline interferometry system named the Event Horizon Imager (EHI) has been proposed to dramatically improve black hole imaging and provide precise tests of the theory of general relativity. We…
We explore the impact of "slow-light" radiative transfer - i.e., general relativistic radiative transfer (GRRT) calculations in which the simulated fluid evolves while light rays are propagating through it - in general relativistic…
A long standing goal in astrophysics is to directly observe the immediate environment of a black hole with angular resolution comparable to the event horizon. Realizing this goal would open a new window on the study of General Relativity in…
We study the most central regions of AGN jets with an angular resolution of tens of micro-arcseconds using VLBI at millimeter wavelengths (mm-VLBI). We present and discuss a new 86 GHz VLBI survey of compact radio sources. We show new high…
We study the general relativistic motion of a bright spot in a jet from an accreting black hole. The corresponding lensed images of the moving bright spot are calculated numerically in discrete time intervals along the bright spot…
The very latest observation of $M87$ supermassive black hole (BH) by the Event Horizon Telescope (EHT) provides the accretion onto BHs is an interesting study in the theory of gravity. We study the geodesics structure and accretion near a…
The observed jet precession period of approximately 11 years for M87* strongly suggests the presence of a supermassive rotating black hole with a tilted accretion disk at the center of the galaxy. By modeling the motion of the tilted…
The spectacular images of the M87 black hole taken by the Event Horizon Telescope (EHT) have opened a new era of black hole research. One of the next issues is to take polarization images around the central black hole (BH). Since radio…
Event Horizon Telescope (EHT) images of the horizon-scale emission around the Galactic Center supermassive black hole Sagittarius A* (Sgr A*) favor accretion flow models with a jet component. However, this jet has not been conclusively…
We investigate the magnetic field configuration of the M87 jet at arc-second scales by using archival polarimetric VLA data at 8, 15, 22 and 43 GHz. By stacking images over three years in order to enhance the sensitivity, we reveal, for the…
We present the results of a VLBI Space Observatory Programme (VSOP) observation of the subparsec structure in Centaurus A at 4.9 GHz. Owing to its proximity, our Centaurus A space-VLBI image is one of the highest spatial resolution images…
High-frequency very-long-baseline interferometry (VLBI) observations can now resolve the horizon-scale emission from sources in the immediate vicinity of nearby supermassive black holes. Future space-VLBI observations will access highly…
Over the past few decades, our knowledge of jets produced by active galactic nuclei (AGN) has greatly progressed thanks to the development of very-long-baseline interferometry (VLBI). Nevertheless, the crucial mechanisms involved in the…
In this paper we review and discuss some of the intriguing properties of the Galactic Center supermassive black hole candidate Sgr A*. Of all possible black hole sources, the event horizon of Sgr A*, subtends the largest angular scale on…
A detailed analysis of the evolution of the properties of core-jet systems within the VLBA Imaging and Polarimetry Survey (VIPS) is presented. We find a power-law relationship between jet intensity and width that suggests for the typical…
Using multi-frequency Very Long Baseline Interferometer (VLBI) observations, we probe the jet size in the optically thick hard state jets of two black hole X-ray binary (BHXRB) systems, MAXI J1820+070 and V404 Cygni. Due to optical depth…