Suzaku Observation of the Intermediate Polar V1223 Sagittarii
  We report on the Suzaku observation of the intermediate polar V1223
Sagittarii. Using a multi-temperature plasma emission model with its reflection
from a cold matter, we obtained the shock temperature to be 37.9^{+5.1}_{-4.6}
keV. This constrains the mass and the radius of the white dwarf (WD) in the
ranges 0.82^{+0.05}_{-0.06} solar masses and (6.9+/-0.4)x10^8 cm, respectively,
with the aid of a WD mass-radius relation. The solid angle of the reflector
viewed from the post-shock plasma was measured to be Omega/2pi = 0.91+/-0.26. A
fluorescent iron Kalpha emission line is detected, whose central energy is
discovered to be modulated with the WD rotation for the first time in
magnetic-CVs. Detailed spectral analysis indicates that the line comprises of a
stable 6.4 keV component and a red-shifted component, the latter of which
appears only around the rotational intensity-minimum phase. The equivalent
width (EW) of the former stable component ~80 eV together with the measured
Omega indicates the major reflector is the WD surface, and the shock height is
not more than 7% of the WD radius. Comparing this limitation to the height
predicted by the Aizu model (1973), we estimated the fractional area onto which
the accretion occurs to be < 7x10^{-3}$ of the WD radius, which is the most
severe constraint in non-eclipsing IPs. The red-shifted iron line component, on
the other hand, can be interpreted as emanating from the pre-shock accretion
flow via fluorescence. Its EW (28^{+44}_{-13} eV) and the central energy
(6.30_{-0.05}^{+0.07} keV) at the intensity-minimum phase are consistent with
this interpretation.
