0220007

IGR J16318-4848 is the first source newly discovered by INTEGRAL. It is most likely a high-mass X-ray binary enshrouded by a dense envelope. The high-energy source is highly variable on time scales exceeding 15 min.A Target of Opportunity observation with XMM-Newton showed a source which is intrinsically absorbed by a high column density of 2x10^{24}/cm^2 together with strong fluorescence lines of exceptional equivalent widths whichdominated the X-ray spectrum. Since the source is variable attempts to model both the soft X-ray and hard X-ray spectrum were hampered by fact that the XMM-Newton observations were not simultaneously with any of the (short) observations performed by INTEGRAL.IGR J1631-4848 will be observed by XMM-Newton on 3 (or possibly 4) occasions as part of its AO-3 program covering time scales from days to months. We here propose observations with INTEGRAL to be done simultaneously with XMM-Newton. This will enable us to better constrain the high-energy spectrum. This is essential to allow an unambiguous decomposition of the variability between the various spectral components.Only a few other examples of high-mass X-ray binary sources with similar spectral characteristics do exist. Also a couple of other sources discovered by INTEGRAL seem to have similar high column densities.New observations may shed therefore also more light on this apparently new class of sources as well as to the possibility of their contribution to the high-energy Galactic background radiation. [truncated! Please see actual data for full text]