the $2-10 \keV$ band (Corcoran 2005). The temperature of the extra soft component is $kT_{\rm soft} \simeq 1.1 \keV$, and its contribution to the $2-10 \keV$ band is expected to be small relative to that of the hot ($kT=3.3 \keV$) component (e.g., Sarazin & Bahcall 1977). Indeed, the hot component contributes $70 \%$ of the observed X-ray emission in the $2-10 \keV$ band (deduced from figures 8 and 9 of H07). Therefore, in fitting the column density based on the X-ray emission in the $2-10 \keV$ band, one better compare it to the column density toward to hot component of H07 (their table 5), rather to the entire spectrum of H07 (the entire spectrum studied by H07 goes below $2 \keV$). In any case, we shall stay with the hot component as it is better defined.

The column density toward the hot gas at phase $0.47$ is $N_H=1.7\times 10^{23} \cm^{-2}$. This is hard to explain in a model where the secondary is toward us during this phase, i.e., $\omega \sim 270^\circ$. This is because the opening angle of the conical shell (the collision surface of the two winds) is $\phi_a \simeq 60^\circ$, while the inclination angle is $i\simeq 42^\circ$. This 