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Mitchell C Begelman

Publications and source records attributed to Mitchell C Begelman.

2 recordsLinked to original sources

Mechanical heating by active galaxies.

Jets and winds are significant channels for energy loss from accreting black holes. These outflows mechanically heat their surroundings, through shocks as well as gentler forms of heating. We discuss recent efforts to understand the nature and distribution of mechanical heating by central active galactic nuclei (AGN) in clusters of galaxies, using numerical simulations and analytic models. Specifically, we will discuss whether the relatively gentle 'effervescent heating' mechanism can compensate for radiative losses in the central regions of clusters, and account for the excess entropy observed at larger radii. J. Binney discusses the possible role of violent, episodic heating by AGN in clusters.

Astronomy↗

Evidence for black holes.

Black holes are common objects in the universe. Each galaxy contains large numbers-perhaps millions-of stellar-mass black holes, each the remnant of a massive star. In addition, nearly every galaxy contains a supermassive black hole at its center, with a mass ranging from millions to billions of solar masses. This review discusses the demographics of black holes, the ways in which they interact with their environment, factors that may regulate their formation and growth, and progress toward determining whether these objects really warp spacetime as predicted by the general theory of relativity.

Journal Article↗