1. Search for Bulk Motion in A2256 with Suzaku and ASTRO-H
UEDA Shutaro, HAYASHIDA Kiyoshi, NAGAI Masaaki, and TAWA Noriaki
(Osaka University)
August Onsen

2. What is Abell 2256? Optical image of Abell 2256
Briel,U.G. et al. 1991
Fusco-Femiano, R. et al. 2005
Rephaelo, Y. & Gruber, D.E. 2003
XIS image of Abell 2256
XIS keV
0.5Mpc
sub
main
Optical image of Abell 2256 (
A2256 is one of the most extensively studied merging clusters with distinctive two peaks (main and sub) near the center1).
A2256 is also one of the clusters in which non-thermal hard X-ray emission was detected with Beppo-SAX 2) and RXTE 3).
We have examined redshift difference of the hot gas in the main and sub clusters in A2256.

3. We measured the redshift of He-like Iron line by using APEC model.
Suzaku Observation
Ueda et al., 2010 in prep
We measured the redshift of He-like Iron line by using APEC model.
MWH
LHB
CXB
ICM
Fig. 1 Spectrum of Main-Cluster
Fig. 2 Spectrum of Sub-Cluster
kT= keV Z=
kT= keV Z=
We found the redshift difference of x10-2 between two regions.
Main
XIS0
XIS1
XIS3
Weighted
mean
Chandra
Sub
Optical galaxies
Fig. 3 Redshift difference between　the main and sub clusters
Optical galaxies
(Berrington et al. 2002)
Chandra
(Sun et al. 2002)

4. Fig 4 : XIS spectrum in 6-8keV range Fig 5 : SXS spectrum in 6-8keV
ASTRO-H Simulation
We performed SXS simulation based on the spectra fit results with Suzaku XIS.
The exposure time of 78ks is assumed.
The SXS Count rate is ~0.4cts/s in the entire band and 2.2x10-3 cts/s in Fe-K lines.
Suzaku XIS
Fig 4 : XIS spectrum in 6-8keV range
SXS Simulation
Fig 5 : SXS spectrum in 6-8keV
Redshift [ x10-2 ]
main
sub
XIS
SXS
Velocity Difference [km/s]
The redshifts of the hot gas in the main and sub clusters will be measured with accuracy of tens of km/s by using ASTRO-H SXS, when we ignore the turbulent flow.
Further SXS simulations in which turbulent flow is considered are presented in the poster.
Table 1 : Redshift obtained with XIS and SXS