Astron. Astrophys. 349, L53-L56 (1999)

2. Observations

The CS (J=21), (32), and (54) transitions have been observed in July 1996 using the IRAM 30 m radio telescope. The beamsizes are 24" at 98 GHz, 16" at 147 GHz and 10" at 245 GHz. Pointing accuracy was better than 3". All spectra were obtained with a velocity resolution better than 0.08 km s^-1 using autocorrelator spectrometers. Maps were obtained with 121 individual positions simultaneously in the three transitions. Spacing between individual positions is 15". Because the observations were obtained under average summer conditions the noise level at the higher frequencies especially at the (54) transition varies significantly. For comparison purpose the C¹⁸O (J=10) data obtained in the key project with the IRAM 30 m telescope (Falgarone et al. 1998) are used. The C¹⁸O map covers a much larger area than the CS maps with 2400 individual positions on a grid; its angular resolution is 22".

© European Southern Observatory (ESO) 1999

Online publication: September 2, 1999
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