BeppoSAX observation of the cluster Abell 970

¹ Instituto de Astronomia, Geofísica e Ciências Atmos. (IAG), Universidade de São Paulo, Brazil
² Divisão de Astrofísica INPE/MCT, 12227-010, São José dos Campos/S.P., Brazil
³ Observatoire de Paris-Meudon, GEPI, 92195 Meudon, France

Corresponding author: G. B. Lima Neto, gastao@astro.iag.usp.br

Received: 1 July 2002
Accepted: 6 November 2002

Abstract

We report new results on the cluster of galaxies Abell 970 obtained from X-ray observation with BeppoSAX. Our analysis of the BeppoSAX MECS and LECS data in the range [0.15–10] keV reveals a mean cluster gas temperature of , a metallicity of , and an interstellar hydrogen absorption column density of  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.