Liyi Gu, Haiguang Xu, Junhua Gu, Madoka Kawaharada, Kazuhiro Nakazawa, Zhenzhen Qin, Jingying Wang, Yu Wang, Zhongli Zhang, Kazuo Makishima
Based on a detailed analysis of the high-quality Chandra, XMM-Newton, and
Suzaku data of the X-ray bright cluster of galaxies Abell 1795, we report clear
evidence for a two-phase intracluster medium (ICM) structure, which consists of
a cool (with a temperature T = 2.0-2.2 keV) and a hot (T = 5.0-5.7 keV)
component that coexist and dominate the X-ray emission at least in the central
80 kpc. A third weak emission component (T = 0.8 keV) is also detected within
the innermost 144 kpc and is ascribed to a portion of inter-stellar medium
(ISM) of the cD galaxy. Deprojected spectral analysis reveals flat radial
temperature distributions for both the hot phase and cool phase components.
These results are consistent with the ASCA measurements reported in Xu et al.
(1998), and resemble the previous findings for the Centaurus cluster (e.g.,
Takahashi et al. 2009). By analyzing the emission measure ratio and gas metal
abundance maps created from the Chandra data, we find that the cool phase
component is more metal-enriched than the hot phase one in 50-100 kpc region,
which agrees with that found in M87 (Simionescu et al. 2008). The coexistence
of the cool phase and hot phase ICM cannot be realized by bubble uplifting from
active galactic nuclei (AGN) alone. Instead, the two-phase ICM properties are
better reconciled with a cD corona model (Makishima et al. 2001). (Abridged)
View original:
http://arxiv.org/abs/1202.3196
No comments:
Post a Comment