Fossil group origins - VI. Global X-ray scaling relations of fossil galaxy clusters
De Grandi, S.; Gastaldello, F.; Jiménez-Bailón, E.; Girardi, M.; Corsini, E. M.; Aguerri, J. A. L.; D'Onghia, E.; Barrena, R.; Sánchez-Janssen, R.; Méndez-Abreu, J.; Kundert, A.; Lozada-Muñoz, M.; Wilcots, E.; Zarattini, S.
United States, Italy, Spain, Mexico, United Kingdom, Canada
Abstract
We present the first pointed X-ray observations of 10 candidate fossil galaxy groups and clusters. With these Suzaku observations, we determine global temperatures and bolometric X-ray luminosities of the intracluster medium (ICM) out to r500 for six systems in our sample. The remaining four systems show signs of significant contamination from non-ICM sources. For the six objects with successfully determined r500 properties, we measure global temperatures in the range 2.8 ≤ TX ≤ 5.3 keV, bolometric X-ray luminosities of 0.8 × 1044 ≤ LX, bol ≤ 7.7 × 1044 erg s-1, and estimate masses, as derived from TX, of M500 ≳ 1014 M⊙. Fossil cluster scaling relations are constructed for a sample that combines our Suzaku observed fossils with fossils in the literature. Using measurements of global X-ray luminosity, temperature, optical luminosity, and velocity dispersion, scaling relations for the fossil sample are then compared with a control sample of non-fossil systems. We find the fits of our fossil cluster scaling relations are consistent with the relations for normal groups and clusters, indicating fossil clusters have global ICM X-ray properties similar to those of comparable mass non-fossil systems.