ROSAT PSPC OBSERVATIONS OF THE INFRARED QUASAR IRAS-13349- EVIDENCE FOR A WARM ABSORBER WITH INTERNAL DUST(2438 )

We present spatial, temporal and spectral analyses of ROSAT Position S ensitive Proportional Counter (PSPC) observations of the infrared-loud quasar IRAS 13349+2438. IRAS 13349+2438 is the archetypal highly pola rized radio-quiet QSO and has an optical/infrared luminosity of approx imate to 2 x 10(46) erg s(-1). We detect variability in the ROSAT coun t rate by a factor of 4.1 in about one year, and there is also evidenc e for approximate to 25 per cent variability within one week. We find no evidence for large intrinsic absorption of soft X-rays by 'cold' ne utral matter. These two facts have important consequences for the scat tering-plus-transmission model of this object which was developed to e xplain its high wavelength-dependent polarization and other properties . The soft X-ray variability makes electron scattering of most of the soft X-rays difficult without a very peculiar scattering mirror. The l ack of significant intrinsic cold X-ray absorption together with the l arge observed E(B - V) suggests either a very peculiar system geometry or, more probably, absorption by 'warm' ionized gas with internal dus t. There is evidence for an ionized oxygen edge in the X-ray spectrum. IRAS 13349+2438 has many properties that are similar to those of 'nar row-line' Seyfert 1s.