Binary Structure and Accretion Flow of the New Intermediate Polar H0253+193

This paper describes X-ray spectral variations of H0253 + 193 during its 6 hr binary orbit and 206 s pulsation. The orbital-phase-resolved X-ray spectra were well fitted by a thermal bremsstrahlung model with a temperature ranging from 16 to 33 keV and an iron emission line at about 6.7 keV. No systematic change of the temperature with orbital phase was found, but a clear orbital modulation of the hydrogen column density (N_H) was discovered. H0253 + 193 shows total eclipses and double-peaked pulse profiles. During the ingress and egress of the eclipse, no significant spectral change was observed. The fractional pulse amplitude decreases as the X-ray energy increases. A possible geometry of the binary system and the structure of the accretion flow are discussed.