THE ORIGIN OF THE SOFT-X-RAY EXCESS IN THE SEYFERT-2 GALAXY NGC-2110

We present and discuss an X-ray image and a medium-resolution X-ray sp ectrum of the Seyfert 2 galaxy NGC 2110 obtained with the high-resolut ion imager (HRI) on ROSAT (0.1-2.4 keV) and Goddard's Broad Band X-Ray Telescope (BBXRT; 0.3-11 keV), respectively. Spatially resolved soft X-ray emission, which peaks 4 '' to the north of the nucleus and near the position of the highest excitation optical emission line gas, is s een in the HRI observation. The extent has a flux of similar to 3 x 10 (-13) ergs cm(-2) s(-1) and accounts for 11% +/- 3% of the total 0.1-2 .4 keV flux. To model the BBXRT spectrum, a soft excess component is r equired which has a flux of similar to 3.5 x 10(-13) ergs cm(-2) s(-1) and accounts for similar to 14% +/- 6% of the total 0.1-2.4 keV flux. In addition, BBXRT confirms the presence of an similar to 175 eV equi valent width Fe Ka fluorescence line in NGC 2110. Because of the good agreement between their fluxes, we propose that the soft excess arises from the spatially resolved X-ray emission, This is contrary to previ ous suggestions that the spectral soft excess in NGC 2110 is due to le akage of the X-ray continuum through a patchy absorber. The temperatur e of the gas responsible for the soft excess is too high to be account ed for by local shock heating. In order to explain the soft excess and extent as either scattered continuum X-rays or fluorescence from gas photoionized by the nuclear source, the hard X-rays must be emitted an isotropically. However, the soft excess and extent can be well modeled as thermal emission from a hot, outflowing wind, which may also be re sponsible for confining at least some portion of the optical narrow li ne-emitting clouds.