X-ray measurement of the elemental abundances at the outskirts of the Perseus cluster with Suzaku

Abstract

We report on the abundance of metals (Mg and Fe) in the intracluster medium (ICM) at the outskirts (0.2 r₂₀₀-0.8 r₂₀₀) of the Perseus cluster. The X-ray spectra were obtained in the Suzaku/XIS mapping observations of this region. We employ single temperature models to fit all the X-ray spectra. The ICM temperature smoothly decreases toward the outer region from 6 keV to 4 keV. The Fe abundance is uniformly distributed at the outskirts (∼ 0.3 solar). The Mg abundance is ∼ 1 solar at the outskirts. The solar ratios of Mg/Fe of the outskirts region (Mg/Fe ∼ 4) are a factor of 4 larger than those of the central region. Various systematic effects, including the spatial fluctuations in the cosmic X-ray background, are taken into account and evaluated. Our results have not changed significantly.