Table 3: Observed lines.
IRAS 16594-4656 IRAS 17150-3224

Molecule Transition Frequency $T_{{\rm mb}}$ $\int T_{\rm mb}{{\rm d}v}$ $T_{{\rm mb}}$ $\int T_{\rm mb}{{\rm d}v}$

GHz K K km s^-1 K K km s^-1

C₃S J = 15-14 86.708 <0.01 <0.03 - -

SiO J = 2-1 86.847 <0.01 <0.03 - -

HN¹³C J = 1-0 87.091 <0.01 <0.03 - -

C₄H $^2\Pi_{3/2}$ , 19/2-17/2 87.372 <0.01 <0.03 - -

C₂H N = 1-0 87.329 <0.01 <0.03 - -

HCN J = 1-0 88.632 0.02 0.47 0.02 0.54

C₃N N = 9-8, J = 19/2-17/2 89.046 <0.01 <0.05 - -

C₃N N = 9-8, J = 17/2-15/2 89.064 <0.01 <0.05 - -

HCO⁺ J = 1-0 89.189 <0.01 <0.05 - -

HC¹³CCN J = 10-9 90.593 <0.01 <0.04 - -

HCC¹³CN J = 10-9 90.602 <0.01 <0.04 - -

HNC J = 1-0 90.664 <0.01 <0.04 - -

SiS J = 5-4 90.772 <0.01 <0.04 - -

HC₃N J = 10-9 90.979 <0.01 <0.04 - -

CH₃CN 5(1)-4(1) 91.985 <0.01 <0.05 - -

HC¹³CCN J = 12-11 108.711 <0.01 <0.06 - -

HCC¹³CN J = 12-11 108.721 <0.01 <0.06 - -

¹³CN N = 1-0 108.780 <0.01 <0.06 - -

C₃N N = 11-10, J = 23/2-21/2 108.834 <0.01 <0.06 - -

C₃N N = 11-10, J = 21/2-19/2 108.853 <0.01 <0.06 - -

SiS J = 6-5 108.924 <0.01 <0.06 - -

HC₃N J = 12-11 109.174 <0.01 <0.06 - -

¹³CO J = 1-0 110.201 0.04 0.06 0.04 0.75

CH₃CN 6(1)-5(1) 110.381 <0.01 <0.11 <0.01 <0.09

C₄H $^2\Pi_{3/2}$ 23/2-21/2 113.266 <0.01 <0.09 <0.01 <0.06

C₂S 8(7)-9(8) 113.410 <0.01 <0.09 <0.01 <0.06

CN N = 1-0 113.491 0.05 3.63 <0.01 <0.06

C₄H $^2\Pi_{3/2}$ 21/2-19/2 115.217 <0.07 <0.76 <0.04 <0.45

CO J = 1-0 115.271 0.61 1.78 0.25 5.05

SiC₂ 5_0,5-4_0,4 115.382 <0.07 <0.76 <0.04 <0.45

SiO J = 3-2 130.269 <0.01 <0.06 - -

H₂CO 2_1,2-1_1,1 140.840 <0.01 <0.07 - -

SiC₂ 6_2,5-5_2,4 140.920 <0.01 <0.07 - -

H¹³CCCN J = 16-15 141.062 <0.01 <0.07 - -

CS J = 3-2 146.969 <0.01 <0.04 - -

CH₃CN 8(0)-7(0) 147.175 <0.01 <0.04 - -

¹³CO J = 2-1 220.399 0.10 1.34 0.13 2.91

CH₃CN 12(0)-11(0) 220.747 <0.01 <0.16 <0.01 <0.17

CN N = 2-1 226.875 0.11 9.91 <0.01 <0.10

CO J = 2-1 230.538 1.75 32.60 0.65 12.84

CO⁺ J = 2-1 235.790 <0.01 <0.12 - -

SiS J = 13-12 235.961 <0.01 <0.12 - -

CH₃CN 13(0)-12(0) 239.138 <0.01 <0.16 - -

CH₃C₂H 14(0)-13(0) 239.252 <0.01 <0.16 - -

C₃H₂ 4_4,1-3_3,0 265.759 <0.02 <0.36 - -

HCN J = 3-2 265.886 0.11 2.85 - -

H¹³CN J = 4-3 345.340 <0.04 <0.80 <0.06 <1.28

HC₃N J = 38-37 345.610 <0.04 <0.80 <0.06 <1.28

CO J = 3-2 345.796 2.05 41.20 0.78 18.19

**Table 3:** Observed lines.
			IRAS 16594-4656		IRAS 17150-3224
Molecule	Transition	Frequency	$T_{{\rm mb}}$	$\int T_{\rm mb}{{\rm d}v}$		$T_{{\rm mb}}$	$\int T_{\rm mb}{{\rm d}v}$
		GHz	K	K km s^-1		K	K km s^-1
C₃S	J = 15-14	86.708	<0.01	<0.03		-	-
SiO	J = 2-1	86.847	<0.01	<0.03		-	-
HN¹³C	J = 1-0	87.091	<0.01	<0.03		-	-
C₄H	$^2\Pi_{3/2}$ , 19/2-17/2	87.372	<0.01	<0.03		-	-
C₂H	N = 1-0	87.329	<0.01	<0.03		-	-
HCN	J = 1-0	88.632	0.02	0.47		0.02	0.54
C₃N	N = 9-8, J = 19/2-17/2	89.046	<0.01	<0.05		-	-
C₃N	N = 9-8, J = 17/2-15/2	89.064	<0.01	<0.05		-	-
HCO⁺	J = 1-0	89.189	<0.01	<0.05		-	-
HC¹³CCN	J = 10-9	90.593	<0.01	<0.04		-	-
HCC¹³CN	J = 10-9	90.602	<0.01	<0.04		-	-
HNC	J = 1-0	90.664	<0.01	<0.04		-	-
SiS	J = 5-4	90.772	<0.01	<0.04		-	-
HC₃N	J = 10-9	90.979	<0.01	<0.04		-	-
CH₃CN	5(1)-4(1)	91.985	<0.01	<0.05		-	-
HC¹³CCN	J = 12-11	108.711	<0.01	<0.06		-	-
HCC¹³CN	J = 12-11	108.721	<0.01	<0.06		-	-
¹³CN	N = 1-0	108.780	<0.01	<0.06		-	-
C₃N	N = 11-10, J = 23/2-21/2	108.834	<0.01	<0.06		-	-
C₃N	N = 11-10, J = 21/2-19/2	108.853	<0.01	<0.06		-	-
SiS	J = 6-5	108.924	<0.01	<0.06		-	-
HC₃N	J = 12-11	109.174	<0.01	<0.06		-	-
¹³CO	J = 1-0	110.201	0.04	0.06		0.04	0.75
CH₃CN	6(1)-5(1)	110.381	<0.01	<0.11		<0.01	<0.09
C₄H	$^2\Pi_{3/2}$ 23/2-21/2	113.266	<0.01	<0.09		<0.01	<0.06
C₂S	8(7)-9(8)	113.410	<0.01	<0.09		<0.01	<0.06
CN	N = 1-0	113.491	0.05	3.63		<0.01	<0.06
C₄H	$^2\Pi_{3/2}$ 21/2-19/2	115.217	<0.07	<0.76		<0.04	<0.45
CO	J = 1-0	115.271	0.61	1.78		0.25	5.05
SiC₂	5_0,5-4_0,4	115.382	<0.07	<0.76		<0.04	<0.45
SiO	J = 3-2	130.269	<0.01	<0.06		-	-
H₂CO	2_1,2-1_1,1	140.840	<0.01	<0.07		-	-
SiC₂	6_2,5-5_2,4	140.920	<0.01	<0.07		-	-
H¹³CCCN	J = 16-15	141.062	<0.01	<0.07		-	-
CS	J = 3-2	146.969	<0.01	<0.04		-	-
CH₃CN	8(0)-7(0)	147.175	<0.01	<0.04		-	-
¹³CO	J = 2-1	220.399	0.10	1.34		0.13	2.91
CH₃CN	12(0)-11(0)	220.747	<0.01	<0.16		<0.01	<0.17
CN	N = 2-1	226.875	0.11	9.91		<0.01	<0.10
CO	J = 2-1	230.538	1.75	32.60		0.65	12.84
CO⁺	J = 2-1	235.790	<0.01	<0.12		-	-
SiS	J = 13-12	235.961	<0.01	<0.12		-	-
CH₃CN	13(0)-12(0)	239.138	<0.01	<0.16		-	-
CH₃C₂H	14(0)-13(0)	239.252	<0.01	<0.16		-	-
C₃H₂	4_4,1-3_3,0	265.759	<0.02	<0.36		-	-
HCN	J = 3-2	265.886	0.11	2.85		-	-
H¹³CN	J = 4-3	345.340	<0.04	<0.80		<0.06	<1.28
HC₃N	J = 38-37	345.610	<0.04	<0.80		<0.06	<1.28
CO	J = 3-2	345.796	2.05	41.20		0.78	18.19

Source LaTeX | All tables | In the text

	1 Introduction
	2 Observations
	3 Sources
	4 CO observations
	5 CO line modelling
	6 Molecular evolution
	7 Discussion
	8 Conclusions
	References
	Online Material
	Appendix A: Molecular line spectra