of measurements in adyacent areas.

Radio images
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### Radio continuum at 1.46 GHz

The distribution of the ionized gas was also investigated using radio continuum data. The surveyed field, which corresponds to the central region of the complex, was observed at 1.465 MHz (20cm) using the Very Large Array in the DnC configuration on 2000 July 3 and 5 as part of the AC555 observing program. The sources 1328+307 ($\equiv$ 3C286l, S$_{1.46GHz}$ = 14.9 Jy) and 1748-253 (S$_{1.46GHz}$ = 1.3 Jy) were used as primary and secondary flux density calibrators, respectively. The bandwidth was 50 MHz and the total integration time 2 hours. The coordinates of the field center are 17$^h$25$^m$856,–34111304 (J2000). The synthesized beam is 439343 at a position angle of +41.

The data were edited, calibrated, self-calibrated, and imaged using AIPS tasks. The rms in the central part of the image is 20 .

### CO line data

Intermediate angular resolution and medium sensitivity [CO]{} data were obtained with the 4-m [NANTEN]{} millimetre-wave telescope of Nagoya University. At the time of the observations this telescope was installed at the Las Campanas Observatory, Chile. The half-power beamwidth and the system temperature, including the atmospheric contribution towards the zenith, 