Midcourse Space Experiment survey of the Galactic plane

The Midcourse Space Experiment (MSX) surveyed the entire Galactic plane within \b\ less than or equal to 15 degrees in four mid-infrared spectral bands between 6 and 25 mum at a spatial resolution of similar to 18."3. The survey was redundant within \b\ less than or equal to 4.degrees5 with four-fold coverage over two-thirds of the area. These survey data were combined to create 1680 1.degrees5 x 1.degrees5 images that cover the region with 6" pixel spacing in each of the spectral bands. The images preserve the inherent resolution of the data but have up to twice the sensitivity of a single scan. The individual survey observations had to be extensively conditioned to achieve the co-add advantage. The noise equivalent radiance (NER) at 8.3 mum, the most sensitive MSX midinfrared spectral band, varies from similar to1.3 MJy sr(-1) in the inner Galaxy to 3 times that at the latitude limits in the outer Galaxy; the sensitivities of the other MSX mid-infrared bands are 10-25 times less. Additionally, 36 lower resolution 10 degrees x 10 degrees images were generated in each band that span the full latitude and longitude range of the survey. These panoramic images have a resolution of similar to1.'2 with 36" pixel spacing and a six-fold improvement in NER, making them an ideal product for comparison with radio surveys of the Galactic plane. An ancillary set of images has been created from other MSX astronomy experiments that lie within 10 degrees of the Galactic plane. These images either extend the latitude coverage of the survey or provide deeper probes of Galactic structure either by themselves or when added to the survey images.