We report the detection of narrow Fe xxv and Fe xxvi X-ray absorption lines at 6.68 \pm 0.04 keV and 6.97 \pm 0.05 keV in the persistent emission of the dipping low-mass X-ray binary 4U 1323 - 62 during a 2003 January XMM-Newton observation .
These features are superposed on a broad emission feature centered on 6.6 ^ { +0.1 } _ { -0.2 } keV .
During dipping intervals the equivalent width of the Fe xxv feature increases while that of the Fe xxvi feature decreases , consistent with the presence of less strongly ionized material in the line-of-sight .
As observed previously , the changes in the 1.0–10 keV spectrum during dips are inconsistent with a simple increase in absorption by cool material .
However , the changes in both the absorption features and the continuum can be modeled by variations in the properties of an ionized absorber .
No partial covering of any component of the spectrum , and hence no extended corona , are required .
From persistent to deep dipping the photo-ionization parameter , \xi , expressed in erg cm s ^ { -1 } , decreases from \log ( \xi ) of 3.9 \pm 0.1 to \log ( \xi ) of 3.13 \pm 0.07 , while the equivalent hydrogen column density of the ionized absorber increases from ( 3.8 \pm 0.4 ) \times~ { } 10 ^ { 22 } atoms cm ^ { -2 } to ( 37 \pm 2 ) \times~ { } 10 ^ { 22 } atoms cm ^ { -2 } .
Since highly-ionized absorption features are seen from many other dip sources , this mechanism may also explain the overall changes in X-ray spectrum observed during dipping intervals from these systems .