ROSATX‐Ray Observations of the Cooling Flow Cluster A2597

The cluster A2597 was observed in X-rays with the ROSAT PSPC and HRIdetectors. The X-ray isophotes are oriented similarly to the optical isophotesof the central cD galaxy and to the isopleths of the galaxy distribution in thecluster, but are otherwise quite regular, suggesting that this cluster isreasonably relaxed and in hydrostatic equilibrium. The merged HRI and PSPCsurface brightness profile is not adequately fit by a beta model because of thecentral X-ray surface brightness peak, indicating the presence of a coolingflow. If the central 108 arcsec in radius are excluded, an acceptable fit isfound which gives beta = 0.64 but only an upper limit to the core radius, rcore< 78 arcsec. Within a radius of 2 Mpc, we found masses of Mgas = 1.2e14 Msunand Mtot = 6.5e14 Msun, and a gas mass fraction of about 19%. Both the overallcluster spectrum and the spatially resolved spectra within 300 kpc require thepresence of both hot gas and a cooling flow in the spectrum. The spectrallydetermined total cooling rate of Mdot = 344 Msun/yr is in good agreement withthose derived from analyses of the X-ray surface brightness profile from theEinstein IPC and the ROSAT HRI images. The ROSAT spatially resolved X-rayspectra indicate that the cooling component is distributed over the inner ~300kpc in radius of the cluster. We do not detect any significant excess X-rayabsorption toward the center of A2597, and we set a very conservative upperlimit on the excess column in front of the cooling flow region of NH < 1.72e20cm**-2.Comment: 16 pages, 12 figures, LaTeX, emulateapj style, Astrophysical Journal in pres