  We present a deep XMM-Newton observation of the extremely massive, rapidly
rotating, relativistic-jet-launching spiral galaxy 2MASX J23453268-0449256.
Diffuse X-ray emission from the hot gaseous halo around the galaxy is robustly
detected out to a radius of 160 kpc, corresponding roughly to 35 per cent of
the virial radius ($\approx 450$ kpc). We fit the X-ray emission with the
standard isothermal $\beta$ model, and it is found that the enclosed gas mass
within 160 kpc is $1.15_{-0.24}^{+0.22} \times 10^{11} \, \rm{M}_{\odot}$.
Extrapolating the gas mass profile out to the virial radius, the estimated gas
mass is $8.25_{-1.77}^{+1.62} \times 10^{11} \, \rm{M}_{\odot}$, which makes up
roughly 65 per cent of the total baryon mass content of the galaxy. When the
stellar mass is considered and accounting for the statistical and systematic
uncertainties, the baryon mass fraction within the virial radius is
$0.121_{-0.043}^{+0.043}$, in agreement with the universal baryon fraction. The
baryon mass fraction is consistent with all baryons falling within $r_{200}$,
or with only half of the baryons falling within $r_{200}$. Similar to the
massive spiral galaxies NGC 1961 and NGC 6753, we find a low value for the
metal abundance of $\approx 0.1 {\rm{Z}}_{\odot}$, which appears uniform with
radius. We also detect diffuse X-ray emission associated with the northern and
southern lobes, possibly attributed to inverse Compton scattering of cosmic
microwave background photons. The estimated energy densities of the electrons
and magnetic field in these radio lobes suggest that they are
electron-dominated by a factor of 10$-$200, depending on the choice of the
lower cut-off energy of the electron spectrum.
