The Midcourse Space Experiment Point Source Catalog Version 2.3 Explanatory Guide

This is a AIR FORCE RESEARCH LAB HANSCOM AFB MA SPACE VEHICLES DIRECTORATE report procured by the Pentagon and made available for public release. It has been reproduced in the best form available to the Pentagon. It is not spiral-bound, but rather assembled with Velobinding in a soft, white linen cover. The Storming Media report number is A399814. The abstract provided by the Pentagon follows: This Explanatory Guide describes Version 2.3 of the Midcourse Space Experiment (MSX) Point Source Catalog. The data calibration and processing are detailed, with particular attention to improvements over the initial published catalog, Version 1.2. The current catalog contains sources extracted from nearly all of the MSX astronomy experiments, including more than 100,000 sources that were not in the previous version. Most of the photometry was extracted from the co-added images, as opposed to the single-scan data, which significantly improves the signal-to-noise ratio of the point sources and hence their reliability. Comparison with Tycho-2 positions indicates that the astrometric accuracy of Version 2.3 is better by about I compared to Version 1.2. In addition to the Galactic Plane, Areas Missed by IRAS, and the Large Magellanic Cloud, which were included in Version 1.2, this release includes data from the Small Magellanic Cloud, eight nearby galaxies, and several molecular clouds and star forming regions.