We present high resolution X-ray observations of the narrow line radio galaxy PKS 1138 - 262 at z = 2.156 with the ACIS-S detector on the Chandra observatory .
These observations show that the X-ray emission from 1138–262 is dominated by emission from the active galactic nucleus ( AGN ) with a 2 to 10 keV luminosity of 4 \times 10 ^ { 45 } erg s ^ { -1 } .
The relative X-ray and radio properties of the AGN in 1138–262 are similar to those seen for the AGN in the archetype powerful radio galaxy Cygnus A .

Between 10 \% and 25 \% ( depending on energy ) of the X-ray emission from 1138–262 is spatially extended on scales of 10 ^ { \prime \prime } to 20 ^ { \prime \prime } .
The extended X-ray emission is elongated , with a major axis aligned with that of the radio source .
While the X-ray and radio emissions are elongated on similar scales and position angles , there is no one-to-one correspondence between the radio and X-ray features in the source .
The most likely origin for the extended X-ray emission in 1138–262 is thermal emission from shocked gas , although we can not rule-out a contribution from inverse Compton emission .
If the emission is from hot gas , the gas density is 0.05 cm ^ { -3 } and the gas mass is 2.5 \times 10 ^ { 12 } M _ { \odot } .
The pressure in this hot gas is adequate to confine the radio emitting plasma and the optical line emitting gas .
We set an upper limit of 1.5 \times 10 ^ { 44 } erg s ^ { -1 } to the ( rest frame ) 2 to 10 keV luminosity of any normal cluster atmosphere associated with 1138–262 .

No emission was detected from any of the Ly \alpha emitting galaxies in the ( proto- ) cluster around 1138–262 , outside of the Ly \alpha halo of 1138–262 itself , to a ( rest frame ) 2 to 10 keV luminosity limit of 1.2 \times 10 ^ { 43 } erg s ^ { -1 } .
Emission was detected from a z = 2.183 QSO located 2 ^ { \prime } west of 1138–262 with a luminosity of 1.8 \times 10 ^ { 44 } erg s ^ { -1 } .