Measuring cluster temperature profiles with XMM/EPIC

Using the PV observation of A1795, we illustrate the capability of XMM-EPIC to measure cluster temperature profiles, a key ingredient for the determination of cluster mass profiles through the equation of hydrostatic equilibrium. We develop a methodology for spatially resolved spectroscopy of extended sources, adapted to XMM background and vignetting characteristics. The effect of the particle induced background is discussed. A simple unbiased method is proposed to correct for vignetting effects, in which every photon is weighted according to its energy and location on the detector. We were able to derive the temperature profile of A1795 up to 0.4 times the virial radius. A significant and spatially resolved drop in temperature towards the center ($r< 200 {\rm kpc}$) is observed, which corresponds to the cooling flow region of the cluster. Beyond that region, the temperature is constant with no indication of a fall-off at large radii out to 1.2 Mpc.

[1]  P. Gondoin,et al.  XMM-Newton observatory. I. The spacecraft and operations , 2001 .

[2]  S. Bardelli,et al.  BeppoSAX-ROSAT PSPC observations of the Shapley supercluster: A3562 , 2000, astro-ph/0006014.

[3]  J. Bregman,et al.  Radial Temperature Profiles of 11 Clusters of Galaxies Observed with BEPPOSAX , 2000, astro-ph/0003123.

[4]  D. White.  Deconvolution of ASCA X-ray data — II. Radial temperature and metallicity profiles for 106 galaxy clusters , 1999, astro-ph/9909467.

[5]  A. Evrard,et al.  Radial Temperature Profiles of X-Ray-emitting Gas within Clusters of Galaxies , 1999, astro-ph/9901406.

[6]  J. Navarro,et al.  The thermal imprint of galaxy formation on X-ray clusters , 1998, Nature.

[7]  Richard F. Mushotzky,et al.  Observational Tests of the Mass-Temperature Relation for Galaxy Clusters , 1998, astro-ph/9902151.

[8]  Jonathan P. D. Mittaz,et al.  Detection of Luminous Intracluster Extreme-Ultraviolet Emission from Abell 1795 , 1998 .

[9]  M. Markevitch,et al.  The Temperature Structure of 30 Nearby Clusters Observed with ASCA: Similarity of Temperature Profiles , 1997, astro-ph/9711289.

[10]  Dan McCammon,et al.  ROSAT Survey Diffuse X-Ray Background Maps. II. , 1997 .

[11]  S. White,et al.  A Universal Density Profile from Hierarchical Clustering , 1996, astro-ph/9611107.

[12]  U. Briel,et al.  An X-ray Temperature Map of Abell 1795, a Galaxy Cluster in Hydrostatic Equilibrium , 1996 .

[13]  A. Evrard,et al.  Mass estimates of X-ray clusters , 1995, astro-ph/9510058.

[14]  Dan McCammon,et al.  First Maps of the Soft X-Ray Diffuse Background from the ROSAT XRT/PSPC All-Sky Survey , 1995 .

[15]  Duane A. Liedahl,et al.  New Calculations of Fe L-Shell X-Ray Spectra in High-Temperature Plasmas , 1995 .

[16]  A. Evrard,et al.  The baryon content of galaxy clusters: a challenge to cosmological orthodoxy , 1993, Nature.