Discovery of ADC absorption in the LMXB XB 1323-619 with XMM-Newton Original Research Article

In our observation of the LMXB XB 1323-619 made with XMM-Newton in January 2003, a number of absorption lines were discovered, notably at 6.70 and 6.98 keV which we identify with scattering by high ionization state ions Fe XXV and Fe XXVI. Curve of growth analysis provided a consistent solution for collisional ionization for a plasma temperature kT = 31 keV, close to the electron temperature we previously obtained for the accretion disc corona (ADC) in this source. Thus, for the first time we can explain the absorption features found in recent years in dipping sources as originating in the ADC. We also find a remarkable linear increase in the rate of X-ray bursts with time implying that the gap between bursts will become zero on January 11 (±4), 2008. We expect the source to undergo a transition from X-ray bursting to X-ray flaring confirming that flaring is unstable nuclear burning.