BeppoSAX observation of the cluster Abell 970
/ Authors
/ Abstract
We report new results on the cluster of galaxies Abell 970 obtained from X-ray observation with BeppoSAX .O ur analysis of the BeppoSAX MECS and LECS data in the range (0.15-10) keV reveals a mean cluster gas temperature of kT = 4.46 +0.14 −0.15 , a metallicity ofZ = 0.31 +0.05 −0.04 Z� , and an interstellar hydrogen absorption column density of NH = 6.05 +1.29 −0.97 ×10 20 cm −2 . Moreover, we obtained azimuthally averaged radial profiles of these quantities. Our results are consistent with the hypothesis that Abell 970 has been disturbed by a past merger or by the ongoing merger process of a substructure, that put the cluster out of equilibrium. This is also demonstrated by the offset between the gas and galaxy distributions. Combining the X-ray data with a recently published analysis of new galaxy radial velocities, we conclude that a subcluster 8 arcmin to the NW is falling into Abell 970 and will merge in a few Gigayears, thus disturbing Abell 970's newly acquired equilibrium. The high α-elements/iron ratio that we derive for this cluster supports the hypothesis of early intracluster medium enrichment by Type II supernovae.
Journal: Astronomy and Astrophysics