1995A&A...297L..37H

We report the discovery of new intermediate polars in the galactic plane, detected during the ROSAT all-sky survey. Three new systems (RX J0028.8+5917, RX J0153.3+7446 and RX J1712.6-2414) are characterized by hard ROSAT spectra, consistent with intrinsically absorbed thermal bremsstrahlung as was seen from intermediate polars known before ROSAT. Another intermediate polar candidate (RX J1914.4+2456) shows together with RX J0558.0+5353 and RE0751+14 a soft black body-like spectrum similar to the soft X-ray spectra of polars. The blackbody temperatures kT for this new class of soft intermediate polars are in the range of about 40-60eV, somewhat higher than typically found for polars. The similarities to polars at the lower end of their magnetic field strength distribution, together with the longer orbital period of RX J0558.0+5353 and RE0751+14, strongly suggest the class of soft intermediate polars as evolutionary progenitors of polars which have not synchronized the orbital and white dwarf rotation yet.