相关论文: Ultra fast outflows, and their connection to accre…
During the last decade, strong observational evidence has been accumulated for the existence of massive, high velocity winds/outflows (aka Ultra Fast Outflows, UFOs) in nearby AGNs and in more distant quasars. Here we briefly review some of…
We describe the physical mechanisms of launching and acceleration of wind from an active galactic nucleus (AGN) accretion disk. We focus on the radiation line force driven and magnetic driven wind models, which operate on the accretion disk…
Ultra-fast outflows (UFOs) are mildly relativistic (outflow velocity $v_{out}>0.1c$) nuclear winds detected as blueshifted absorption lines from highly ionized, dense gas in the X-ray spectra of active galactic nuclei. The AGN feedback…
Powerful winds at accretion-disk scales have been observed in the past 20 years in many AGN. These are the so-called ultrafast outflows (UFOs). Outflows are intimately related to mass accretion through the conservation of angular momentum,…
Ultra-fast outflows (UFOs) are highly ionized, mildly relativistic winds seen in the X-ray spectra of active galactic nuclei (AGN) and are thought to contribute to AGN feedback and galaxy evolution. We investigate UFO signatures by…
We show, using global 3D grid-based hydrodynamical simulations, that Ultra Fast Outflows (UFOs) from Active Galactic Nuclei (AGN) result in considerable feedback of energy and momentum into the interstellar medium (ISM) of the host galaxy.…
Large-scale, broad outflows are common in active galaxies. In systems where star formation coexists with an AGN, it is unclear yet the role that both play on driving the outflows. In this work we present three-dimensional radiative-cooling…
X-ray evidence for ultra-fast outflows (UFOs) has been recently reported in a number of local AGNs through the detection of blue-shifted Fe XXV/XXVI absorption lines. We present the results of a comprehensive spectral analysis of a large…
Active galactic nucleus (AGN) feedback is the process by which supermassive black holes in the centres of galaxies may moderate the growth of their hosts. Gas outflows from supermassive black holes release huge quantities of energy into the…
Using the results of a previous X-ray photo-ionization modelling of blue-shifted Fe K absorption lines on a sample of 42 local radio-quiet AGNs observed with XMM-Newton, in this letter we estimate the location and energetics of the…
Ultra Fast Outflows (UFOs) are an established feature in X-ray spectra of AGNs. According to the standard picture, they are launched at accretion disc scales with relativistic velocities, up to 0.3-0.4 c. Their high kinetic power is enough…
UltraFast Outflows (UFO) are observed in some active galactic nuclei (AGN), with blueshifted and highly ionised Fe-K absorption features. AGN typically have a UV bright accretion flow, so UV line driving is an obvious candidate for…
Understanding the astrophysics of feedback in active galactic nuclei (AGN) is key to understanding the growth and co-evolution of supermassive black holes and galaxies. AGN-driven winds/outflows are potentially the most effective way of…
Ultrafast outflows (UFOs) are the most extreme winds launched by active galactic nuclei (AGN) due to their mildly-relativistic speeds (~0.1-0.3c) and are thought to significantly contribute to galactic evolution via AGN feedback. Their…
The extreme velocities and high ionization states of ultra-fast outflows (UFOs) make them a promising candidate for AGN feedback on the evolution of the host galaxy. However, their exact underlying driving mechanism is not yet fully…
We study outflows driven by Active Galactic Nuclei (AGNs) using high- resolution simulations of idealized z=2 isolated disk galaxies. Episodic accretion events lead to outflows with velocities >1000 km/s and mass outflow rates up to the…
Bright AGN frequently show ultra-fast outflows (UFOs) with outflow velocities vout ~0.1c. These outflows may be the source of AGN feedback on their host galaxies sought by galaxy formation modellers. The exact effect of the outflows on the…
Ultra-fast outflows (UFOs) with mildly relativistic velocities are measured using the X-ray spectra of radio-quiet and -loud active galactic nuclei (AGNs). In general, UFOs are believed to be generated from the accretion disk around a black…
Ultra-fast outflows (UFOs) are seen in many AGN, giving a possible mode for AGN feedback onto the host galaxy. However, the mechanism(s) for the launch and acceleration of these outflows are currently unknown, with UV line driving…
The time lag between soft and hard X-ray photons has been observed in many active galactic nuclei (AGN) and can reveal the accretion process and geometry around supermassive black holes (SMBHs). High-frequency Fe K and soft lags are…