Left: normalized unfolded spectrum toward one of the sightlines. The z = 0 absorption lines of O VII Kα, O VII Kβ, and O VIII Kα are shown. Middle: contours of N(O VII) and total broadening of O VII, b _total for the measured equivalent widths of Kα and Kβ lines toward the same sightline. The saturation-corrected N(O VII) and corresponding b _total are shown with the red point. Right: ionization fraction of O VII and O VIII, X _{O VII} and X _{O VIII} , as a function of temperature in collisional ionization equilibrium. The temperature and X _{O VII} toward the same sightline obtained from the column density ratio of O VIII and O VII (see Equation (3b)) is shown with the red point.