Complex structure of galaxy cluster A1689: Evidence for a merger from X-ray data?
2004 (English)In: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 607, no 1, 190-201 p.Article in journal (Refereed) Published
A1689 is a galaxy cluster at z = 0.183 for which previous measurements of its mass by using various techniques gave discrepant results. We present a new detailed measurement of the mass with the data based on X-ray observations with the European Photon Imaging Camera aboard the XMM-Newton Observatory, determined by using an unparameterized deprojection technique. Fitting the total mass profile to a Navarro-Frenk-White model yields halo concentration c = 7.2(-2.4)(+1.6) and r(200) = 1.13 +/- 0.21 h(-1) Mpc, corresponding to a mass that is less than half of that found from gravitational lensing. Adding to the evidence of substructure from optical observations, X-ray analysis shows a highly asymmetric temperature profile and a nonuniform redshift distribution, implying large-scale relative motion of the gas. A lower than expected gas mass fraction f(gas) = 0.072 +/- 0: 008 (for a flat LambdaCDM cosmology) suggests a complex spatial and/or dynamical structure. We also find no sign of any additional absorbing component previously reported on the basis of the Chandra data, confirming the XMM-Newton low-energy response by using data from ROSAT.
Place, publisher, year, edition, pages
2004. Vol. 607, no 1, 190-201 p.
dark matter, galaxies : clusters : individual (A1689), X-rays : galaxies : clusters
Astronomy, Astrophysics and Cosmology
IdentifiersURN: urn:nbn:se:kth:diva-44873DOI: 10.1086/383258ISI: 000221523900015ScopusID: 2-s2.0-3042596604OAI: oai:DiVA.org:kth-44873DiVA: diva2:451518
QC 201110262011-10-262011-10-252011-10-26Bibliographically approved