We analyzed a deep XMM-Newton observation of the cluster of galaxies Hydra A , focusing on the large-scale shock discovered in Chandra images as a discontinuity in the surface brightness .
The shock front can be seen both in the pressure map and in temperature profiles in several sectors .
We compared the results of a spherically symmetric hydrodynamic model to surface brightness profiles and temperature jumps across the shock to determine the shock properties .
The Mach numbers determined from the temperature jumps are in good agreement with the Mach numbers derived from EPIC/pn surface brightness profiles and previously from Chandra data and are consistent with M \sim 1.3 .
In this simple model , the estimated shock age in the different sectors ranges between 130 and 230 Myr and the outburst energy between 1.5 and 3 \times 10 ^ { 61 } ergs .
The shape of the shock seen in the pressure map can be approximated with an ellipse centered \sim 70 kpc towards the NE from the cluster center .
This is a good simple approximation to the shock shape seen in the Chandra image , although this shape shows additional small deviations from ellipticity .
We aimed to develop a better model that can explain the offset between the shock center and the AGN , as well as give a consistent result on the shock age and energy .
To this end , we performed 3D hydrodynamical simulations in which the shock is produced by a symmetrical pair of AGN jets launched in a spherical galaxy cluster .
As an explanation of the observed offset between the shock center and the AGN , we consider large-scale bulk flows in the intracluster medium , which were included in the simulation .
The simulation successfully reproduces the size , ellipticity , and average Mach number of the observed shock front .
The predicted age of the shock is 160 Myr and the total input energy 3 \times 10 ^ { 61 } erg .
Both values are within the range determined by the spherically symmetric model .
To match the observed 70 kpc offset of the shock ellipse from the cluster center by large-scale coherent motions , these would need to have a high velocity of 670 \textrm { km } \textrm { s } ^ { -1 } .
We discuss the feasibility of this scenario and offer alternative ways to produce the observed offset and to further improve the simulation .