相关论文: Exploring the disk-jet connection in NGC 315

We report on the study of an intriguing active galaxy that was selected as a potential multiple supermassive black hole merger in the early-type host SDSS J151709.20+335324.7 (z=0.135). Ground-based SDSS imaging reveals two blue structures…

Black hole accretion flows can be divided into two broad classes: cold and hot. Cold accretion flows, which consist of cool optically thick gas, are found at relatively high mass accretion rates. Prominent examples are the standard thin…

We present evidence for the presence of a transition in the accretion properties of radio-loud sources. For a sample of radio galaxies and radio-loud quasars, selected based on their extended radio properties, the accretion rate is…

Recent observations suggest that in black hole X-ray binaries jet/outflow formation is related to the hot plasma in the vicinity of the black hole, either in the form of an advection-dominated accretion flow at low accretion rates or in a…

We present a model for the accretion flow around the supermassive black hole in the LINER nucleus of NGC 1097 which fits the optical to X-ray spectral energy distribution (SED). The X-ray segment of the SED is based on observations with the…

The nearby face-on spiral galaxy NGC 2617 underwent an unambiguous 'inside-out' multi-wavelength outburst in Spring 2013, and a dramatic Seyfert type change probably between 2010 and 2012, with the emergence of broad optical emission lines.…

Highly-ionized fast accretion-disk winds have been suggested as an explanation for a variety of observed absorption and emission features in the X-ray spectra of Active Galactic Nuclei. Simple estimates have suggested that these flows may…

Here we discuss the effects of strong gravity that can be observed in electromagnetic spectra of active galactic nuclei (AGN). According to the unification model of an AGN, there is a supermassive black hole ($10^7 - 10^9 M_\odot$) in its…

We have investigated electro-magnetic (EM) wave pulses in a jet from a neutrino driven accretion flow (NDAF) around a black hole (BH). NDAFs are massive accretion disks whose accretion rates of $\dot{M}\approx 0.01 - 10…

In studies of accreting black holes in binary systems, empirical relations have been proposed to quantify the coupling between accretion processes and ejection mechanisms. These processes are probed respectively by means of X-ray and…

We propose the scenario to interpret the overall observational features of the SS433--W50 system. The most unique features of SS433 are the presence of the precessing, mildly relativistic jets and the obscuration of the central engine,…

Black-hole accretion systems are known to possess several distinct modes (or spectral states), such as low/hard state, high/soft state, and so on. Since the dynamics of the corresponding flows is distinct, theoretical models were separately…

We use Chandra X-ray data and Very Large Array radio observations for a sample of 20 nearby, massive, X-ray bright, early-type galaxies to investigate the relation between the Bondi accretion rates and the mechanical jet powers. We find a…

Non-blazar radio-galaxies emitting in the very-high-energy (VHE; >100 GeV) regime offer a unique perspective for probing particle acceleration and emission processes in black hole (BH) accretion-jet systems. The misaligned nature of these…

Recent numerical simulations of MHD jets from accretion disks are briefly reviewed with emphasis on the scaling law for jet speed and the role of magnetic reconnection in relation to time variability in accretion disks, jets, and flares. On…

Compact radio active galactic nuclei (compact radio AGN) are compact ($\leq$ 20 kpc), powerful radio sources. Currently, the preferred scenario is that they are at the early stage of AGN evolution. At present, the research of compact radio…

We have calculated stationary models for accretion disks around super-massive black holes in galactic nuclei. Our models show that below a critical mass flow rate of ~3 10**-3 M_Edd advection will dominate the energy budget while above that…

The early-type galaxy NGC 3115, at a distance of 10.2 Mpc, hosts the nearest billion-solar-mass black hole. Wong et al. recently inferred a substantial Bondi accretion rate near the black hole. Bondi-like accretion is thought to fuel…

In this paper we study the wind accretion onto a rotating black hole in the close binary system harboring a young massive star. It is shown that the angular momentum of the accreted stellar wind material is not sufficient for the formation…

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…