A two-micron Galactic survey

The first results are presented here of the Two-Micron Galactic Survey (TMGS). The TMGS is the most sensitive near-infrared survey of the Galactic plane yet attempted on a large scale. The Galactic plane has been drift-scanned in several regions over the areas −5° < l < 30°, |b| ≤ 15° and 30° < l < 180°, |b| ≤ 5°. The discussion in this paper concentrates mainly on three extensively mapped areas centred on δ = −1°, −23° and −30°, covering a total of 138 deg 2 of sky. The survey is complete in the areas covered to magnitude m K ≃ + 9.8 mag. So far, a total area of 255 deg 2 has been mapped and 470 000 objects have been detected, the majority of these in the Galactic plane and with no known visible counterparts