Related papers: Observing positive and negative AGN feedback
We perform two dimensional hydrodynamic numerical simulations to study the positive active galactic nucleus feedback which triggers, rather than suppresses, star formation. Recently, it was shown by Nayakshin et al. and Ishibashi et al.…
I review accretion and outflow in active galactic nuclei. Accretion appears to occur in a series of very small--scale, chaotic events, whose gas flows have no correlation with the large--scale structure of the galaxy or with each other. The…
In these proceedings I briefly: (1) review the impact (or "feedback") that active galactic nuclei (AGN) are predicted to have on their host galaxies and larger scale environment, (2) review the observational evidence for or against these…
Observations point towards a close connection between nuclear starbursts, active galactic nuclei (AGN), and outflow phenomena. An evolutionary sequence, starting from a dust-obscured ultra-luminous infrared galaxy and eventually leading to…
The inefficiency of star formation in massive elliptical galaxies is widely believed to be caused by the interactions of an active galactic nucleus (AGN) with the surrounding gas. Achieving a sufficiently rapid reddening of moderately…
Theoretical models and numerical simulations have established a framework of galaxy evolution in which galaxies merge and create dual supermassive black holes (with separations of one to ten kiloparsecs), which eventually sink into the…
Observations of AGN have suggested a possible delay between the peak of star formation (on some scale) and AGN activity. Inefficient fueling (and/or feedback) from fast stellar winds has been invoked to explain this, but we argue this is…
A major amendment in recent models of hierarchical galaxy formation is the inclusion of so-called AGN feedback. The energy input from an active central massive black hole is invoked to suppress star formation in early-type galaxies at later…
In recent years, numerous active galactic nuclei have been discovered in ever smaller galaxies, questioning the paradigm that dwarf galaxies do not harbour central massive black holes. Even if such black holes exist, feeding them by gas…
It has always been believed that feedback from active galactic nuclei (AGN) has an important impact on star formation in massive galaxies. Black hole spin is an important physical parameter of AGN. We use a large sample of massive…
Feedback from active galactic nuclei (AGN) is widely considered to be the main driver in regulating the growth of massive galaxies through heating or driving gas out of the galaxy, preventing further increase in stellar mass. Observational…
Accreting black holes can release enormous amounts of energy to their surroundings, in various forms. Such feedback may profoundly influence a black hole's environment. After briefly reviewing the possible types of feedback, I focus on the…
AGN outflows can remove large quantities of gas from their host galaxy spheroids, potentially shutting off star formation. On the other hand, they can compress this gas, potentially enhancing or triggering star formation, at least for short…
The increasing observational evidence of galactic outflows is considered as a sign of active galactic nucleus (AGN) feedback in action. However, the physical mechanism responsible for driving the observed outflows remains unclear, and…
Simulations of galaxy growth need to invoke strong negative feedback from active galactic nuclei (AGN) to suppress the formation of stars and thus prevent the over-production of very massive systems. While some observations provide evidence…
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…
The role of active galactic nuclei (AGN) feedback in dwarf galaxies remains poorly understood, with conventional wisdom suggesting it primarily suppresses star formation. Using high-resolution MACER3D simulations that directly resolve the…
I show that Eddington accretion episodes in AGN are likely to produce winds with velocities $v \sim 0.1c$ and ionization parameters up to $\xi \sim 10^4$ (cgs), implying the presence of resonance lines of helium-- and hydrogenlike iron.…
The main requirements for fueling an active galactic nucleus and to form massive black holes are reviewed. Low-luminosity AGN can be fueled easily from the local star clusters, near the nucleus, and the various stellar processes are…
Analysis of spectral absorption features has led to the identification of several distinct outflow components in AGNs. The outflowing gas is evidently photoionized by the nuclear continuum source and originates in the accretion flow toward…