were 26 and $\sim$220K (SSB) at 115 GHz.

The data were gathered using the position switching mode. Observations of points devoid of [CO]{} emission were interspersed among the program positions. The coordinates of these points were retrieved from a database that was kindly made available to us by the [NANTEN]{} staff. The spectrometer used was an acusto-optical with 2048 channels providing a velocity resolution of $\sim$ 0.055 . For intensity calibrations, a room-temperature chopper wheel was employed @penzias73. An absolute intensity calibration was achieved by observing Orion [KL]{} (RA,Dec. \[J2000\] = 5$^h$40$^m$145, $-$5$^\circ$22493) and $\rho$ Oph East (RA,Dec. \[J2000\] = 16$^h$32$^m$228, –24$^\circ$28331). The absolute radiation temperature, T$_R^\ast$, of Orion [KL]{} and $\rho$ Oph East were assumed to be 65 K and 15 K, respectively [@ulich76; @kutner81].

The [CO]{} observations were carried out in April 2001 and the surveyed area is defined by 35251$\leq$ [*l*]{} $\leq$35395 and [^4]. An inner area defined by 35296 $\leq$ [*l*]{} $\leq$35350 and 059$\leq$ [*b*]{} $\leq$ 113[^5] was sampled at one beam width intervals, while the remaining area was sampled every 54 (two beamwidths). The total number of observed pointings is 349. The integration time per pointing was 16s resulting in a typical rms noise of 