10^{-5} \zeta M_\odot \yr^{-1}$. From figure 3 of P09 we see that during the X-ray minimum the conical shell is wind-up in such a way that the secondary wind cannot escape. At phase 1.02 (40 days after periastron passage) the wind can propagate at most $20 \AU$ before encountering the primary dense wind; most of the secondary wind is shocked at a much closer distance of $< 5 \AU$. It does it within $20 \AU/ 3000 \km \s^{-1} = 12$ day, which is shorter than the time since minimum starts, but not by much. The volume of space available for the shocked secondary wind is $\Delta V  \sim (20\AU)^3 \simeq 3 \times 10^{43} \cm^{3}$. The mass blown during this time (40 days) is $\Delta M=1.1 \times 10^{-6} \zeta M_\odot$. The proton number density is $$n_p \simeq  3 \times 10^7 \zeta \cm^{-3}.
\label{eq:np}$$ At a temperature of $10^8 \K$ the emissivity is $\Lambda =2.5 \times 10^{-23} \erg \s^{-1} \cm^3$, and the total X-ray luminosity of the bubble is (about half emitted in the $2-10 \keV$ band) $$L_{xm} \simeq 2 \times 10^{35}
\left( \frac{\zeta}{0.5} \right)^2  \erg \s^{-1}.
\label{eq:lx}$$ The emission measure ${\rm EM} \equiv n_p n_e \Delta V$, where $n_e$ is the 