THE 4TH MIT-GREEN BANK 5 GHZ SURVEY

The MIT-Green Bank IV (MG IV) 5 GHz survey covers 0.504 sr of sky in the right ascension range 15.5h-2.5h, between +37.00-degrees and +50.98-degrees declination (B1950). The final MG IV catalog contains 3427 sources detected with a signal-to-noise ratio greater than 5. The catalog was produced from two separate north and south surveys with the National Radio Astronomy Observatory (NRAO)3 91 m transit telescope. The north survey was produced from data collected while scanning the telescope north from +39.00-degrees to +50.98-degrees declination, and the south survey from data collected from scans from +48.98-degrees to +37.00-degrees declination. The completeness and reliability of the final source list is checked by examination of north and south source lists in a twice observed comparison region, lying between +39.15-degrees and +48.83-degrees declination and excluding the area between +/- 10-degrees Galactic latitude. The comparison region covers 0.270 sr of sky and contains 1094 sources. In this region, the MG IV catalog contains 423 sources brighter than 90 mJy and is shown to be 99.1% +/- 1.2% complete at this flux density level. Spectral indices are computed for sources identified in the NRAO 1400 MHz Survey (Condon and Broderick 1985). A comparison of the spectral index distributions between +/- 10-degrees Galactic latitude is presented.