11–14 Aug 2014
Niels Bohr Institute
Europe/Copenhagen timezone

Cosmic ray heating in cool core clusters

13 Aug 2014, 09:00
25m
Auditorium A (Niels Bohr Institute)

Auditorium A

Niels Bohr Institute

Blegdamsvej 17 Copenhagen

Speaker

Dr Christoph Pfrommer (HITS)

Description

Feedback by active galactic nuclei 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 the brightest cluster galaxies. I consider a model where the heating is provided by the damping of Alfvén waves that are excited by streaming cosmic rays (CRs). Recent radio observations of M87 by LOFAR suggest effective mixing of CRs with the cluster gas and the amount of CRs necessary to explain the observed gamma rays by Fermi and HESS is just right to balance the radiative cooling observed in the X-rays, providing a natural explanation for the observed temperature floor as shown by a thermal instability analysis. I will show first AREPO simulations of the non-linear interplay of CRs that are coupled to magneto-hydrodynamics with the goal to support this picture.

Primary author

Dr Christoph Pfrommer (HITS)

Presentation materials