IGR J16318-4848: An X-ray source in a dense envelope?

We analyze in detail the ASCA observations of the hard X-ray Source IGR J16318-4848, which was recently discovered by the INTEGRAL observatory (Courvoisier el al. 2003). The Source has an anomalously hard spectrum in the energy range 0.5-10 keV and is virtually undetectable below 4 keV because of strong photoabsorption (n(H)L > 4 X 10(23) cm(-2)). The Kalpha line of neutral or weakly ionized iron with an equivalent width of similar to2.5 keV dominates in the energy range 4-10 keV. There is also evidence for the presence of a second line at energy similar to7 keV. Our analysis of archival observational data for the infrared counterpart of IGR J16318-4848 that was discovered by Foschini el al. (2003) revealed the source in the wavelength range 1-15 mum. Available data Suggest that the object can be an X-ray binary system surrounded by a dense envelope. The source may be a high-mass X-ray binary similar to GX 301-2. We believe that IGR J16318-4848 can be the first representative of a hitherto unknown Population of strongly absorbed Galactic X-ray sources that Could not be detected by previous X-ray observatories. (C) 2003 MAIK Nauka/Interperiodica.