Characterization of the most highly-ionized absorbers in dipping LMXBs

We propose three 60 ksec and one 140 ks XMMNewton observations of the dippingLowMass Xray Binaries (LMXBs) XB 1254690 and 4U 1746371. We will obtain upto virgul12 ks of dip data per 4U 1254690 observation which will be sufficient toreliably measure the dip properties and the changes in the absorber, compared tothe persistent emission. The 140 ks of the 4U 174612 observation, added to aprevious 50 ks XMMNewton observation on this source, will be enough to detectwith high significance the Fe XXVI absorption feature seen in the previousobservation at low confidence in the persistent emission and Fe XXV and/or FeXXVI absorption features in the dipping emission. The significant detection ofthese lines will allow the absorber properties to be unambigously characterized. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]