The EXOSAT medium-energy slew survey catalog

We present a catalog of X-ray sources observed during slew maneuvers by the Medium Energy Detector Array onboard the EXOSAT Observatory. The EXOSAT Me dium Energy slew-survey catalog (EXMS) provides a unique record of the 1 - 8 keV X-ray sky between 1983 and 1986. 98% of the sky was observed, with 85 % receiving an exposure of >60 s. 1210 sources were detected. By comparing these source positions with other catalogs, identifications are given for 9 92 detections (82% of the sample). These identifications consist of 250 dis tinct objects, including 95 different X-ray binary systems, and 14 differen t AGN. A further 58 detections have multiple candidates, while 160 detectio ns remain unidentified. Collimator transmission corrected 1 - 8 keV count r ates are given for the identified sources: together with raw count rates fo r the other detections. The construction of the EXMS and the checks perform ed to ensure the validity of the derived source properties are discussed. A publically available version of this catalog is maintained on the EXOSAT d atabase and archive system (telnet: //xray@exosat.estec.esa.nl).