A multi-wavelength study of the long-period AM Her system E2003+225. I - The soft X-ray light curve and overall energy spectrum

X-ray, UV and optical data are presented of the longest period AM Her object, E2003+225, from October 12, 1983, together with a new linear polarization ephemeris. The optical and X-ray data were obtained simultaneously and the UV observations were carried out on the same day. A 6-hr observation with the Exosat 500 line/mm objective grating restricts soft X-ray blackbody temperatures to the range 18-29 eV. The blackbody luminosity exceeds the hard X-ray luminosity by at least a factor of 4.5, but is of the same order as the optical/UV component. Soft (0.1-0.25 keV) and hard X-ray (1-6 keV) light curves covering almost two orbital periods are presented and discussed.