相关论文: General relativistic magnetohydrodynamical simulat…
The supermassive black hole in the center of the Milky Way, Sgr A*, displays a nearly flat radio spectrum that is typical for jets in active galactic nuclei. Indeed, time-dependent magnetized models of radiatively inefficient accretion…
The recent 230 GHz observations of the Event Horizon Telescope (EHT) are able to image the innermost structure of the M87 and show a ring-like structure which is in agreement with thermal synchrotron emission generated in a torus…
The nearby radio galaxy M87 is a prime target for studying black hole accretion and jet formation^{1,2}. Event Horizon Telescope observations of M87 in 2017, at a wavelength of 1.3 mm, revealed a ring-like structure, which was interpreted…
Over the past decades, there has been significant progress in our understanding of accreting supermassive black holes (SMBHs) that drive active galactic nuclei (AGNs), both from observational and theoretical perspectives. As an iconic…
In this paper the jet model for the supermassive black hole candidate Sgr A* in the Center of the Galaxy is reviewed. The most recent model, with a reduced set of parameters, is able to account for all major radio properties of the source:…
Non-VLBI measurements of Faraday rotation at mm wavelengths have been used to constrain mass accretion rates ($\mdot$) onto supermassive black holes in the centre of the Milky Way and in the centre of M87. We constructed general…
The galaxy M 87 harbors a kiloparsec-scale relativistic jet, whose origin coincides with a supermassive black hole. Observational mm-VLBI campaigns are capable of resolving the jet-launching region at the scale of the event horizon. In…
Ongoing millimeter VLBI observations with the Event Horizon Telescope allow unprecedented study of the innermost portion of black hole accretion flows. Interpreting the observations requires relativistic, time-dependent physical modeling.…
We have derived simplified equations for a freely expanding, pressure driven jet model as a function of jet power and applied it successfully to the radio cores in the black hole candidates GRS 1915+105, NGC 4258, and M81 which are…
We present results of recent observations and theoretical modeling of data from black holes accreting at very low luminosities (L/L_Edd ~ 10^{-8}). We discuss our newly developed time-dependent model for episodic ejection of relativistic…
We analytically model stationary and axisymmetric active galactic nucleus jets, assuming energy conservation along each magnetic flux tube. Using very-long-baseline interferometry (VLBI) observations and published general relativistic…
Black hole accretion and jet production are areas of intensive study in astrophysics. Recent work has found a relation between radio luminosity, X-ray luminosity, and black hole mass. With the assumption that radio and X-ray luminosity are…
The radio source Sagittarius A* (Sgr A*) is believed to be a hot, inhomogeneous, magnetized plasma flowing near the event horizon of the 3 million solar mass black hole at the galactic center. At a distance of 8000 parsecs the black hole…
The supermassive black hole candidate at the center of M87 drives an ultra-relativistic jet visible on kiloparsec scales, and its large mass and relative proximity allow for event horizon scale imaging with very long baseline interferometry…
M87 is arguably the best supermassive black hole (BH) to explore the jet and/or accretion physics due to its proximity and fruitful high-resolution multi-waveband observations. We model the multi-wavelength spectral energy distribution…
Approximately 10% of active galactic nuclei exhibit relativistic jets, which are powered by accretion of matter onto super massive black holes. While the measured width profiles of such jets on large scales agree with theories of magnetic…
Black hole accretion is one of nature's most efficient energy extraction processes. When gas falls in, a significant fraction of its gravitational binding energy is either converted into radiation or flows outwards in the form of black…
A general relativistic model for the formation and acceleration of low mass-loaded jets from systems containing accreting black holes is presented. The model is based on previous numerical results and theoretical studies in the Newtonian…
Spectral fits to M87 core data from radio to hard x-ray are generated via a specially selected software suite, comprised of the HARM GRMHD accretion disk model and a 2D Monte Carlo radiation transport code. By determining appropriate…
M87 has been the target of numerous astronomical observations across the electromagnetic spectrum and Very Long Baseline Interferometry (VLBI) resolved an edge-brightened jet. However, the origin and formation of its jets remain unclear. In…