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AGN feedback through sound wave dissipation

journal contribution
posted on 2023-05-17, 07:47 authored by Stanislav ShabalaStanislav Shabala, Alexander, P
We investigate the possibility of explaining the observed ripples in the X-ray gas in the Perseus and Virgo clusters through natural oscillations of a perturbed radio cocoon. Such a perturbation would result from an expanding overpressured cocoon of radio plasma overshooting its pressure equilibrium point with the cluster gas. The oscillations are heavily acoustically damped, and energy injection rates required to sustain them are consistent with observed AGN powers. Viscous dissipation of sound waves generated by these oscillations heats the cluster gas. By comparing our model with observations in Perseus and Virgo, we reproduce the observed ripple separations and amplitudes. Spitzer viscosity is largely sufficient in explaining the gas density profile, suggesting that thermal conductivity is likely to be heavily suppressed. In the central regions, viscous heating can suppress cooling flows on timescales exceeding the radio source lifetime.

History

Publication title

Astrophysics and Space Science

Volume

311

Pagination

311-315

ISSN

0004-640X

Department/School

School of Natural Sciences

Publisher

Kluwer Academic Publ

Place of publication

Van Godewijckstraat 30, Dordrecht, Netherlands, 3311 Gz

Rights statement

The final publication is available at http://www.springerlink.com

Repository Status

  • Restricted

Socio-economic Objectives

Expanding knowledge in the physical sciences

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