2 Observations

Between November 18-26, 1988 we used the 15-m SEST to observe ¹²CO(1-0), ¹³CO(1-0), C¹⁸O(1-0) and CS(2-1) towards seven sources. Towards one source we observed only ¹²CO(1-0) and ¹³CO(1-0) and towards one other source only CS(2-1) was observed.

We used a Schottky receiver in combination with a high-resolution AOS (channel width 43.3 kHz). We used frequency switching with an offset of 15 or 20 MHz, depending on the line width. Maps in ¹²CO covering the outflow region were made on a raster with spacing of 20 $^{\prime \prime }$ near the IRAS source, and 40 $^{\prime \prime }$ in the outer parts of the map. Due to time constraints we have ¹³CO data at only nine positions on a 40 $^{\prime \prime }$ raster for each source, centered on the IRAS PSC position. C¹⁸O and CS were traced on a 20 $^{\prime \prime }$ raster until the emission vanished in the noise. A low-order polynomial baseline was subtracted from the spectra before folding. The pointing was regularly checked on SiO masers; its rms uncertainty is 7 $^{\prime \prime }$. The observed sources are listed in Table 1. It gives the source name in Col. 1; the position in equatorial and galactic coordinates in Cols. 2-5. The velocity of the main component is in Col. 6. In Cols. 7 and 8 are the kinematic distance (except for two sources for which a photometric distance is known) and bolometric luminosity (from WB89). Associated sources are shown in Col. 9. The observed transitions and frequencies are given in Cols. 1 and 2 of Table 2. The beam size of the SEST (Col. 3) is between 46 $^{\prime \prime }$ at 115 GHz and 54 $^{\prime \prime }$ at 98 GHz. In Col. 4 we give the rms noise level in the spectra. All intensities in this paper are on the $T_{\rm {A}}^*$ scale. When deriving cloud masses and outflow parameters, we corrected for the main beam efficiency of the SEST (0.70 at all frequencies observed here).

   

Table 2: Observed transitions

Molecule	Frequency	HPBW	rms1
	(MHz)	(arcsec)	(K)
$^{12}{\rm C}^{16}{\rm O}$(1-0)	115271.204	46	0.22 (0.13)
$^{13}{\rm C}^{16}{\rm O}$(1-0)	110201.353	48	0.10 (0.05)
$^{12}{\rm C}^{18}{\rm O}$(1-0)	109782.182	48	0.13 (0.05)
$^{12}{\rm C}^{32}{\rm S}$(2-1)	97980.968	54	0.20 (0.10)
1 rms in brackets at IRAS PSC position (or outflow peak).