IAU Symposium Abstract S186-060P

Associated X-ray emission, Ionized Gas, and Dust Extinction in NGC 5846

Paul Goudfrooij1 and Ginevra Trinchieri2,3
1 Space Telescope Science Institute, Baltimore, U.S.A. < goudfroo@stsci.edu >
2 Max-Planck-Institut f\"ur extraterrestrische Physik, Garching, Germany < ginevra@rosat.mpe-garching.mpg.de >
3 Osservatorio Astronomico di Brera, Milano, Italy

We present new optical multicolor imagery as well as ROSAT PSPC and HRI X-ray imagery of the X-ray-bright elliptical galaxy NGC 5846. A filamentary dust lane is detected in the central region of NGC 5846, with a morphology strikingly similar to that observed for the optical nebulosity {\it and\/} the X-ray emission. A physical connection between the different phases of the interstellar medium therefore seems likely. The extinction properties of the dust are entirely normal'', following the Galactic extinction curve. The energy deposited from the hot gas into heating of the dust grains is consistent with the temperature distribution of the X-ray-emitting gas, which is found to be lowest in the dusty regions. We argue that the dust as well as the optical nebulosity are products of a past interaction with a small, gas-rich galaxy, not remnants of a cooling flow.