Open AccessTHERMAL AND CHEMICAL EVOLUTIONS OF GALAXY CLUSTERS OBSERVED WITH SUZAKU
Author(s) -
Kosuke Sato,
Kyoko Matsushita,
Yoshitaka Ishisaki,
Noriko Y. Yamasaki,
T. Ohashi
Publication year - 2013
Publication title -
acta polytechnica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.207
H-Index - 15
eISSN - 1805-2363
pISSN - 1210-2709
DOI - 10.14311/ap.2013.53.0583
Subject(s) - physics , astrophysics , intracluster medium , metallicity , virial theorem , supernova , galaxy , galaxy cluster , hydrostatic equilibrium , nucleosynthesis , radius , astronomy , computer security , computer science
We studied the properties of the intracluster medium (ICM) of galaxy clusters to outer regions observed with Suzaku. The observed temperature dropped by about ~30% from the central region to the virial radius of the clusters. The derived entropy profile agreed with the expectation from simulations within r 500 , while the entropy profile in r > r 500 indicated a flatter slope than the simulations. This would suggest that the cluster outskirts were out of hydrostatic equilibrium. As for the metallicity, we studied the metal abundances from O to Fe up to ~0.5 times the virial radius of galaxy groups and clusters. Comparing the results with supernova nucleosynthesis models, the number ratio of type II to Ia supernovae is estimated to be ~3.5. We also calculated not only Fe, but also O and Mg mass-to-light ratios (MLRs) with K-band luminosity. The MLRs in the clusters had a similar feature.