Cooling Flows or Heating Flows?

It is now clear that AGN heat cooling flows, largely by driving winds. The winds may contain a relativistic component that generates powerful synchrotron radiation, but it is not clear that all winds do so. The spatial and temporal stability of the AGN/cooling flow interaction are discussed. Collima...

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Autor principal: Binney, J
Formato: Journal article
Publicado em: 2003
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author Binney, J
author_facet Binney, J
author_sort Binney, J
collection OXFORD
description It is now clear that AGN heat cooling flows, largely by driving winds. The winds may contain a relativistic component that generates powerful synchrotron radiation, but it is not clear that all winds do so. The spatial and temporal stability of the AGN/cooling flow interaction are discussed. Collimation of the winds probably provides spatial stability. Temporal stability may be possible only for black holes with masses above a critical value. Both the failure of cooling flows to have adiabatic cores and the existence of X-ray cavities confirm the importance of collimated outflows. I quantify the scale of the convective flow that the AGN Hydra would need to drive if it balanced radiative inward flow by outward flow parallel to the jets. At least in Virgo any such flow must be confined to r<~20 kpc. Hydrodynamical simulations suggest that AGN outbursts cannot last longer than ~25 Myr. Data for four clusters with well studied X-ray cavities suggests that heating associated with cavity formation approximately balances radiative cooling. The role of cosmic infall and the mechanism of filament formation are briefly touched on.
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spelling oxford-uuid:1360f702-8c5b-496e-aa66-14a14a6031f92022-03-26T10:13:29ZCooling Flows or Heating Flows?Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:1360f702-8c5b-496e-aa66-14a14a6031f9Symplectic Elements at Oxford2003Binney, JIt is now clear that AGN heat cooling flows, largely by driving winds. The winds may contain a relativistic component that generates powerful synchrotron radiation, but it is not clear that all winds do so. The spatial and temporal stability of the AGN/cooling flow interaction are discussed. Collimation of the winds probably provides spatial stability. Temporal stability may be possible only for black holes with masses above a critical value. Both the failure of cooling flows to have adiabatic cores and the existence of X-ray cavities confirm the importance of collimated outflows. I quantify the scale of the convective flow that the AGN Hydra would need to drive if it balanced radiative inward flow by outward flow parallel to the jets. At least in Virgo any such flow must be confined to r<~20 kpc. Hydrodynamical simulations suggest that AGN outbursts cannot last longer than ~25 Myr. Data for four clusters with well studied X-ray cavities suggests that heating associated with cavity formation approximately balances radiative cooling. The role of cosmic infall and the mechanism of filament formation are briefly touched on.
spellingShingle Binney, J
Cooling Flows or Heating Flows?
title Cooling Flows or Heating Flows?
title_full Cooling Flows or Heating Flows?
title_fullStr Cooling Flows or Heating Flows?
title_full_unstemmed Cooling Flows or Heating Flows?
title_short Cooling Flows or Heating Flows?
title_sort cooling flows or heating flows
work_keys_str_mv AT binneyj coolingflowsorheatingflows