Simultaneous X-ray and UV spectroscopy of the symbiotic HD 154791/4U 1700+24

4U 1700+24 and GX 1+4 are the only two symbiotic binaries out of virgul200 thatcontain neutronstars. Observationally, the two systems are quite different. Inorder to understand these differences, we propose a 26 ks XMMNewton observationof 4U 1700+24 to carry out simultaneous Xray and UV spectroscopy, and also totest the windaccretion model. Using RGS, we will resolve the emission featurenear 0.6 keV seen by ASCA, measure the constituent line centre energies andwidths, and estimate abundances in the lineemitting material. With the OM, wewill investigate the relationship between the Xray and nebular UV line emission. Finally, we will compare the results to our approved Chandra observationof GX 1+4 as part of a broader project focussing on wind accretion in LMXBs. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]