Okabe & Umetsu 2008
http://adsabs.harvard.edu/abs/2008PASJ...60..345O
2008/01/01
Suzaku Observations of AWM 7 Cluster of Galaxies: Temperatures, Abundances, and Bulk Motions
Sato et al.
http://adsabs.harvard.edu/abs/2008PASJ...60S.333S
We carried out 3 observations of the cluster of galaxies AWM 7, for the central region and 20'-east and 20'-west offset regions, with Suzaku. Temperature and abundance profiles were measured out to 27' simeq 570 h70-1kpc, which corresponded to ˜0.35r180. The temperature of the intra-cluster medium (ICM) slightly decreased from 3.8keV at the center to 3.4keV in the ˜0.35 r180 region, indicating a flatter profile than those in other nearby clusters. The abundance ratio of Si to Fe was almost constant in our observations, while the Mg-to-Fe ratio increased with radius from the cluster center. The O to Fe ratio in the west region showed an increase with radius, while that in the east region was almost flat, though the errors were relatively large. These features suggest that the enrichment process is significantly different between products of type II supernovae (O and Mg) and those by type Ia supernovae (Si and Fe). We also examined the positional shift of the central energy of a He-like Fe-Kα line, in search of possible rotation of the ICM. The 90% upper limit for the line-of-sight velocity difference was derived to be Δ v lesssim 2000kms-1, suggesting that the ellipticity of AWM 7 is rather caused by a recent directional infall of gas along the large-scale filament.
http://adsabs.harvard.edu/abs/2008PASJ...60S.333S
We carried out 3 observations of the cluster of galaxies AWM 7, for the central region and 20'-east and 20'-west offset regions, with Suzaku. Temperature and abundance profiles were measured out to 27' simeq 570 h70-1kpc, which corresponded to ˜0.35r180. The temperature of the intra-cluster medium (ICM) slightly decreased from 3.8keV at the center to 3.4keV in the ˜0.35 r180 region, indicating a flatter profile than those in other nearby clusters. The abundance ratio of Si to Fe was almost constant in our observations, while the Mg-to-Fe ratio increased with radius from the cluster center. The O to Fe ratio in the west region showed an increase with radius, while that in the east region was almost flat, though the errors were relatively large. These features suggest that the enrichment process is significantly different between products of type II supernovae (O and Mg) and those by type Ia supernovae (Si and Fe). We also examined the positional shift of the central energy of a He-like Fe-Kα line, in search of possible rotation of the ICM. The 90% upper limit for the line-of-sight velocity difference was derived to be Δ v lesssim 2000kms-1, suggesting that the ellipticity of AWM 7 is rather caused by a recent directional infall of gas along the large-scale filament.
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