The Bell Laboratories (CO)-C-13 survey: Longitude-velocity maps

A survey is presented of the Galactic plane in the J = 1-0 transition of (C O)-C-13. About 73,000 spectra were obtained with the 7 m telescope at Bell Laboratories over a 10 yr period. The coverage of the survey is (l, b) = (- 5 degrees to 117 degrees, - 1 degrees to 1 degrees), or 244 deg(2), with a grid spacing of 3 ' for /b/ < 0.<degrees>5 and a grid spacing of 6 ' for / b/ > 0.degrees5. The data presented here have been resampled onto a 3 ' gri d. For 0.68 km s(-1) channels, the rms noise level of the survey is 0.1 K o n the T-R* scale. The raw data have been transformed into FITS format, and all the reduction processes, such as correcting for emission in the referen ce positions, baseline removal, and interpolation, were conducted within IR AF using the FCRAO task package and additional programs. The reduced data a re presented here in the form of longitude-velocity color maps at each lati tude. These data allow identification and classification of molecular cloud s with masses in excess of similar to 10(3) M-circle dot throughout the fir st quadrant of the Galaxy. Spiral structure is manifested by the locations of the largest and brightest molecular clouds.