We present an analysis of the X-ray spectrum of the Local Bubble , obtained by simultaneously analyzing spectra from two XMM-Newton pointings on and off an absorbing filament in the Southern galactic hemisphere ( b \approx - 45 \arcdeg ) .
We use the difference in the Galactic column density in these two directions to deduce the contributions of the unabsorbed foreground emission due to the Local Bubble , and the absorbed emission from the Galactic halo and the extragalactic background .
We find the Local Bubble emission is consistent with emission from a plasma in collisional ionization equilibrium with a temperature \log ( T _ { \mathrm { LB } } / \mathrm { K } ) = 6.06 ^ { +0.02 } _ { -0.04 } and an emission measure \int n _ { \mathrm { e } } ^ { 2 } \mathrm { d } l = 0.018 \mbox { cm } ^ { -6 } pc .
Our measured temperature is in good agreement with values obtained from ROSAT All-Sky Survey data , but is lower than that measured by other recent XMM-Newton observations of the Local Bubble , which find \log ( T _ { \mathrm { LB } } / \mathrm { K } ) \approx 6.2 ( although for some of these observations it is possible that the foreground emission is contaminated by non-Local Bubble emission from Loop I ) .
The higher temperature observed towards other directions is inconsistent with our data , when combined with a FUSE measurement of the Galactic halo O vi intensity .
This therefore suggests that the Local Bubble is thermally anisotropic .

Our data are unable to rule out a non-equilibrium model in which the plasma is underionized .
However , an overionized recombining plasma model , while observationally acceptable for certain densities and temperatures , generally gives an implausibly young age for the Local Bubble ( \lesssim 6 \times 10 ^ { 5 } yr ) .