INFRARED PHOTOMETRIE AND SPECTROSCOPY OF THE DRACO NEBULA

the draco nebula is a high latitude molecular cloud which is supposed to interact with hi high velocity clouds (hvcs). hi 21cm line observa tions suggest that the edge of the draco nebula towards low galactic latitudes and longitudes is representing a low velocity shock front due to the collisional interaction between the hvcs and galactic disk gas. the unusual high co abundance compared to neutral hydrogen found at this edge and the enhanced soft xray background emission found in the region of the draco nebula also fit into this picture. however a final confirmation of this interaction scenario fails up to now. we propose to use pht to observe the emission of the dust in order to look for variations of the dust temperature and composition across this filament. in addition we want to observe with the lws the fine structure lines of cii (158 um), oi (63 um) and nii (122 um) across the same feature. these lines will give information about the heating/cooling balance of this filament and on the density and tempe rature variations. moreover, we want to look for small, very small grains and especially pahs in the draco nebula, using the short wavelength bands of pht. since the draco nebula has dust counterparts in all four iras bands, this nebula is a prominent candidate for the detection of pahs in a galactic cirrus cloud and as well for studying the influence of a shock wave on these very small particles. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]