Temperature and entropy profiles of nearby cooling flow clusters observed with XMM-Newton

¹ Institute of Theoretical Physics, University of Zürich, Winterthurerstrasse, 190, 8057 Zürich, Switzerland e-mail: piff@physik.unizh.ch
² Laboratory for Astrophysics, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
³ SRON National Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrecht, The Netherlands
⁴ Institute of Space and Astronautical Science, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 229-8510, Japan

Received: 24 August 2004
Accepted: 1 December 2004

Abstract

We investigate temperature and entropy profiles of 13 nearby cooling flow clusters observed with the EPIC cameras of XMM-Newton. When normalized and scaled by the virial radius the temperature profiles turn out to be remarkably similar. At large radii the temperature profiles show a clear decline starting from a break radius at ~. The temperature decreases by ~ between and . As expected for systems where non-gravitational processes are of great importance, the scale length characterizing the central temperature drop is not found to be proportional to the virial radius of the system. The entropy of the plasma increases monotonically moving outwards almost proportional to the radius and the central entropy level is tightly correlated with the core radius of the X-ray emission. The dispersion in the entropy profiles is smaller if the empirical relation is used instead of the standard self-similar relation and, as expected for cooling flow clusters, no entropy cores are observed.