Suzaku Constraints on the Soft and Hard Excess Emissions from Abell 2199

Authors:
M. Kawaharada, K. Makishima, T. Kitaguchi, S. Okuyama,
K. Nakazawa, and Y. Fukazawa

http://arxiv.org/abs/0911.5205

The nearby ($z=0.03015$) cluster of galaxies Abell 2199 was observed
by Suzaku in X-rays, with five pointings for ~20 ks each. From the
XIS data, the temperature and metal abundance profiles were derived
out to ~700 kpc (0.4 times virial radius). Both these quantities
decrease gradually from the center to peripheries by a factor of ~2,
while the oxygen abundance tends to be flat. The temperature within 12'
(~430 kpc) is ~4 keV, and the 0.5--10 keV X-ray luminosity integrated
up to 30'is (2.9 +- 0.1) x 1E44 erg s^{-1}, in agreement with previous
XMM-Newton measurements. Above this thermal emission, no significant
excess was found either in the XIS range below ~1 keV, or in the
HXD-PIN range above ~15$ keV. The 90%-confidence upper limit on the
emission measure of an assumed 0.2 keV warm gas is (3.7--7.5) x 1E62
cm^{-3} arcmin^{-2},  which is 3.7--7.6 times tighter than the detection
reported with XMM-Newton. The 90%-confidence upper limit on the 20--80
keV luminosity of any power law component is 1.8 x 10^{43} erg s^{-1},
assuming a photon index of 2.0. Although this upper limit does not
reject the possible 2.1 sigma detection by the BeppoSAX PDS, it is a
factor of 2.1 tighter than that of the PDS if both are considered upper
limits. The non-detection of the hard excess can be reconciled with
the upper limit on diffuse radio emission, without invoking the very
low magnetic fields (< 0.073 uG) which were suggested previously.

X-ray Spectroscopy of the Core of the Perseus Cluster with Suzaku: Elemental Abundances in the Intracluster Medium

http://adsabs.harvard.edu/abs/2009ApJ...705L..62T

Tamura et al. 2009

The results from Suzaku observations of the central region of the Perseus cluster are presented. Deep exposures with the X-ray Imaging Spectrometer provide high-quality X-ray spectra from the intracluster medium. X-ray lines from helium-like Cr and Mn have been detected significantly for the first time in clusters. In addition, elemental abundances of Ne, Mg, Si, S, Ar, Ca, Fe, and Ni are accurately measured within 10' (or 220 kpc) from the cluster center. The relative abundance ratios are found to be within a range of 0.8-1.5 times the solar value. These abundance ratios are compared with previous measurements, those in extremely metal-poor stars in the Galaxy, and theoretical models.

Suzaku Observation of the Ophiuchus Galaxy Cluster: One of the Hottest Cool Core Clusters

copy from http://adsabs.harvard.edu/abs/2008PASJ...60.1133F
fujita et al.　2008

We present the analysis of a Suzaku observation of the Ophiuchus galaxy cluster. We confirmed that the cluster has a cool core. While the temperature of the intracluster medium (ICM) decreases toward the center, the metal abundance increases. Except for the core (r lesssim 50kpc), the cluster is hot (˜9-10keV) and is almost isothermal for r lesssim 1Mpc; the latter contradicts a previous study. We do not detect any variation of the redshift of the ICM in the cluster; the upper limit of the velocity difference is 3000km s^-1. The iron-line ratios in X-ray spectra indicate that the ICM has reached the ionization equilibrium state. From these results, we conclude that the Ophiuchus cluster is not a major merger cluster, but one of the hottest clusters with a cool core. We obtain the upper limit of non-thermal emission from the cluster, which is consistent with both the recent claimed detection with INTEGRAL and the recent upper limits with the Swift/BAT. If the cluster has bright non-thermal emission, as suggested by the INTEGRAL measurement, it is probably not due to a recent major cluster merger.

ASCA Compilation of X-Ray Properties of Hot Gas in Elliptical Galaxies and Galaxy Clusters: Two Breaks in the Temperature Dependences

Fukazawa, Makishima, Ohashi

http://adsabs.harvard.edu/abs/2004PASJ...56..965F

Utilizing ASCA archival data of about 300 objects of elliptical galaxies, groups, and clusters of galaxies, we performed systematic measurements of the X-ray properties of hot gas in their systems, and compiled them in this paper. The steepness of the luminosity-temperature (LT) relation, Li_X ∝ (kT)^α, in the range of kT ˜ 1.5 ‑ 15 keV is α = 3.17 &plusmn 0.15, consistent with previous measurements. In the relation, we find two breaks at around ICM temperatures of 1 keV and 4 keV: α = 2.34 ± 0.29 above 4 keV, 3.74 ± 0.32 in 1.5-5 keV, and 4.03 ± 1.07 below 1.5keV. Such two breaks are also evident in the temperature and size relation. The steepness in the LT relation at kT > 4 keV is consistent with the scale-relation derived from the CDM model, indicating that the gravitational effect is dominant in richer clusters, while poorer clusters suffer non-gravity effects. The steep LT relation below 1keV is almost attributed to X-ray faint systems of elliptical galaxies and galaxy groups. We found that the ICM mass within the scaling radius R₁₅₀₀ follows the relation of M_gas ∝ T^2.33±0.07 from X-ray faint galaxies to rich clusters. Therefore, we speculate that even such X-ray faint systems contain a large-scale hot gas, which is too faint to detect.