相关论文: Heating Hot Atmospheres with Active Galactic Nucle…
Using broadband optical imaging and Chandra X-ray data for a sample of 46 cluster central dominant galaxies (CDGs), we investigate the connection between star formation, the intracluster medium (ICM), and the central active galactic nucleus…
The assumption that radiative cooling of gas in the centers of galaxy clusters is approximately balanced by energy input from a central supermassive black hole implies that the observed X-ray luminosity of the cooling flow region sets a…
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…
It is widely accepted that feedback from active galactic nuclei (AGN) plays a key role in the evolution of gas in groups and clusters of galaxies. Unequivocal evidence comes from quasi-spherical X-ray cavities observed near cluster centers…
Recent cosmological simulations have shown that turbulence should be generally prevailing in clusters because clusters are continuously growing through matter accretion. Using one-dimensional hydrodynamic simulations, we study the heating…
Galactic jets are powerful energy sources reheating the intra-cluster medium in galaxy clusters. Their crucial role in the cosmic puzzle, motivated by observations, has been established by a great number of numerical simulations missing the…
Chandra images of galaxy clusters have revealed a wealth of structure unseen by previous generations of low resolution X-ray observatories. In the cores of clusters, bright, irregular X-ray emission is now routinely seen within central…
The analysis of a deep (579 ks) Chandra ACIS pointing of the elliptical galaxy NGC4278, which hosts a low luminosity AGN and compact radio emission, allowed us to detect extended emission from hot gas out to a radius of \sim 5 kpc, with a…
Active Galactic Nuclei (AGN) in cosmological simulations generate explosive feedback that regulates star formation in massive galaxies, modifying the gas phase structure out to large distances. Here, we explore the direct effects that AGN…
AGN outflows are the heat given up when gas in a galaxy evolves towards thermodynamic equilibrium. Indeed, while AGN feedback regulates the growth of massive galaxies, its origins can be understood as the spontaneous thermodynamic process…
Feedback by active galactic nuclei (AGNs) appears to be critical in balancing radiative cooling of the low-entropy gas at the centers of galaxy clusters and in mitigating the star formation of elliptical galaxies. New observations of M87…
We analyse those objects in the Brightest 55 sample of clusters of galaxies which have a short central cooling time and a central temperature drop. Such clusters are likely to require some form of heating. Where clear radio bubbles are…
Active galactic nucleus (AGN) powered jets can accelerate cosmic ray electrons, leading to the observed radio synchrotron emission. To simulate this emission, jet dynamics in galaxy clusters must be coupled to electron spectral modelling.…
Most of the ordinary matter in the local Universe has not been converted into stars but resides in a largely unexplored diffuse, hot, X-ray emitting plasma. It pervades the gravitational potentials of massive galaxies, groups and clusters…
Cluster cooling flow models that include both thermal conduction and AGN heating have lower overall mass cooling rates and simultaneously sustain density and temperature profiles similar to those observed with no ad hoc mass dropout. To…
We investigate a series of steady-state models of galaxy clusters, in which the hot intracluster gas is efficiently heated by active galactic nucleus (AGN) feedback and thermal conduction, and in which the mass accretion rates are highly…
Chandra X-ray Observatory has revealed X-ray cavities in many nearby cooling flow clusters. The cavities trace feedback from the central active galactic nulceus (AGN) on the intracluster medium (ICM), an important ingredient in stabilizing…
We put forward an alternative view to the Bondi-driven feedback between heating and cooling of the intra-cluster medium (ICM) in cooling flow galaxies and clusters. We adopt the popular view that the heating is due to an active galactic…
The importance of the radiative feedback from massive black holes at the centers of elliptical galaxies is not in doubt, given the well established relations among electromagnetic output, black hole mass and galaxy optical luminosity. We…
We describe 2D gasdynamical models of jets that carry mass as well as energy to the hot gas in galaxy clusters. These flows have many attractive attributes for solving the galaxy cluster cooling flow problem: Why the hot gas temperature and…