We report the Suzaku /XIS & HXD and Chandra /ACIS-I results on the X-ray spectra of the Phoenix cluster at the redshift z = 0.596 .
The spectrum of the intracluster medium ( ICM ) is well-reproduced with the emissions from a low temperature ( \sim 3.0 keV and \sim 0.76 solar ) and a high temperature ( \sim 11 keV and \sim 0.33 solar ) plasmas ; the former is localized at the cluster core , while the latter distributes over the cluster .
In addition to these ICM emissions , a strongly absorbed power-law component is found , which is due to an active galactic nucleus ( AGN ) in the cluster center .
The absorption column density and unobscured luminosity of the AGN are \sim 3.2 \times 10 ^ { 23 } cm ^ { -2 } and \sim 4.7 \times 10 ^ { 45 } ergs s ^ { -1 } ( 2 - 10 keV ) , respectively .
Furthermore , a neutral iron ( Fe i ) K-shell line is discovered for the first time with the equivalent width ( EW ) of \sim 150 eV at the rest frame .
The column density and the EW of the Fe i line are exceptionally large for such a high luminosity AGN , and hence the AGN is classified as a type 2 quasi-stellar object ( QSO ) .
We speculate that the significant fraction of the ICM cooled gas would be consumed to maintain the torus and to activate the type 2 QSO .
The Phoenix cluster has a massive starburst in the central galaxy , indicating suppression in the cooling flow is less effective .
This may be because the onset of the latest AGN feedback has occurred recently and it has not yet been effective .
Alternatively , the AGN feedback is predominantly in radiative-mode not in kinetic-mode and the torus may work as a shield to reduce its effect .