  We present XMM-Newton observations around the sightline of Mrk 421. The
emission spectrum of the Milky Way circumgalactic medium (CGM) shows that a two
phase model is a better fit to the data compared to a single phase model; in
addition to the warm-hot virial phase at log ($T/$K) = $6.33_{-0.02}^{+0.03}$,
a hot super-virial phase at log ($T/$K) = $6.88_{-0.07}^{+0.08}$ is required.
Furthermore, we present observations of five fields within 5 degrees of the
primary field. Their spectra also require a two-phase model at warm-hot and hot
temperatures. The hot phase, first discovered in Das et al. 2019, appears to be
widespread. By chemical tagging we show that emission from the supevirial phase
comes from the L-shell transitions of Fe XVIII-FeXXII, and that the range of
temperatures probed in emission is distinct from that in absorption. We detect
scatter in temperature and emission measure (EM) in both the phases, and deduce
that there is small-scale density inhomogeneity in the MW CGM. The emitting gas
likely has higher density, possibly from regions close to the disk of the MW,
while the absorption in the virial phase may arise from low-density gas
extended out to the virial radius of the MW. The presence of the super-virial
phase far from the regions around the Galactic center implicates physical
processes unrelated to the activity at the Galactic center. Hot outflows
resulting from star-formation activity throughout the Galactic disk are likely
responsible for producing this phase.
