Letter to the Editor

An XMM-Newton view of the extended “filament” near the cluster of galaxies Abell 85

¹ Institut d'Astrophysique de Paris, CNRS, 98bis Bd Arago, 75014 Paris, France
² Instituto de Astronomia, Geofísica e C. Atmosf./USP, R. do Matão 1226, 05508-090 São Paulo/SP, Brazil
³ Harvard Smithsonian Center for Astrophysics, 60 Garden St, Cambridge, MA 02138, USA
⁴ MPI für Astrophysik, Karl Schwarzschild Strasse 1, 85740 Garching, Germany

Corresponding author: F. Durret, durret@iap.fr

Received: 12 February 2003
Accepted: 21 March 2003

Abstract

We have observed with XMM-Newton the extended 4 Mpc filament detected by the ROSAT PSPC in the neighbourhood of the cluster of galaxies Abell 85. We confirm that there is an extended feature, aligned at the same position angle as the major axis of the central cD, the bright cluster galaxies, and nearby groups and clusters. We find that the X-ray emission from the filament is best described by thermal emission with a temperature of ~2 keV, which is significantly lower than the ambient cluster medium, but is significantly higher than anticipated for a gas in a weakly bound extended filament. It is not clear whether this is a filament of diffuse emission, a chain of several groups of galaxies, or stripped gas from the infalling south blob.