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.

Suzaku Observation of the Radio Halo Cluster Abell 2319: Gas Dynamics and Hard X-ray Properties

http://adsabs.harvard.edu/abs/2009arXiv0909.1358S
Sugawara et al 2009

We present the results of Suzaku observation of the radio halo cluster Abell 2319. The metal abundance in the central cool region is found to be higher than the surrounding region, which was not resolved in the former studies. We confirm that the line-of-sight velocities of the intracluster medium in the observed region are consistent with those of the member galaxies of entire A2319 and A2319A subgroup for the first time, though any velocity difference within the region is not detected. On the other hand, we do not find any signs of gas motion relevant to A2319B subgroup. Hard X-ray emission from the cluster is clearly detected, but its spectrum is likely thermal. Assuming a simple single temperature model for the thermal component, we find that the upper limit of the non-thermal inverse Compton component becomes $2.6 \times 10^{-11}$ erg s$^{-1}$ cm$^{-2}$ in the 10-40 keV band, which means that the lower limit of the magnetic field is 0.19 $\mu$G with the radio spectral index 0.92. Although the results slightly depend on the detailed spectral modeling, it is robust that the upper limit of the power-law component flux and lower limit of the magnetic field strength become $\sim 3 \times 10^{-11}$ erg s$^{-1}$ cm$^{-2}$ and $\sim 0.2 \mu$G, respectively. Considering the lack of a significant amount of very hot ($\sim 20$ keV) gas and the strong bulk flow motion, it is more likely that the relativistic non-thermal electrons responsible for the radio halo are accelerated through the intracluster turbulence rather than the shocks.

DISTRIBUTION OF TEMPERATURE AND ENTROPY OF INTRACLUSTER MEDIUM OF ABELL 478 UP TO VIRIAL RADIUS

Matsushita et al.
Suzaku AO5 proposal
approved as priority-B

tamura is Co-I.

UNVEILING THE INTERPLAY AMONG ICM, LARGE-SCALE STRUCTURE AND DARK MATTER OUT TO VIRIAL RADIUS OF A1835 (Suzaku AO5 proposal)

by Okabe et al.
(tamura is co-I)
approved as priority-B,
observed 2010-6.7

file name: okabe08suzakuA1835outskirt_ao5

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.