Fakultäten » Mathematisch-naturwissenschaftliche Fakultät » Physik-Institut » Prof. Dr. Philippe Jetzer » Piffaretti

Completed research project

Title / Titel Temperature and entropy profiles of nearby cooling flow clusters observed with XMM-Newton
PDF Abstract (PDF, 14 KB)
Summary / Zusammenfassung 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 ~0.1 r (vir) . The temperature decreases by ~30 % between 0.1 r (vir) and 0.5 r (vir) . 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 S ∝ T ^0.65 is used instead of the standard self-similar relation S ∝ T and, as expected for cooling flow clusters, no entropy cores are observed.
Publications / Publikationen Astronomy and Astrophysics, Volume 433, Issue 1,
April I 2005, pp.101-111
Keywords / Suchbegriffe galaxies: clusters: general, cooling flows, X-rays:, galaxies: clusters
Project leadership and contacts /
Projektleitung und Kontakte
Dr. R. Piffaretti (Project Leader)  
Prof Dr. Philippe Jetzer  
Funding source(s) /
Unterstützt durch
Universität Zürich (position pursuing an academic career), SNF (Personen- und Projektförderung)
In collaboration with /
In Zusammenarbeit mit
Kaastra, J. S.
Duration of Project / Projektdauer Apr 2004 to Apr 2005