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Table 1.
Lines targeted and used in this analysis.
| Molecule | j → k | Frequency | ncrit(a) | μ0(b) |
|---|---|---|---|---|
| (GHz) | (cm−3) | (Debye) | ||
| HCN | 2–1 | 177.26 | 2.8 × 106 | 3.93 |
| HCO+ | 2−1 | 178.38 | 4.2 × 105 | 2.98 |
| CO | 1–0 | 115.27 | 3.0 × 103 | 0.11 |
Notes.
(a)
Critical densities (optically thin approximation) are provided at 20 K for HCN and HCO+ (Shirley 2015) and 100 K for CO (Lequeux 2005). We refer to Shirley (2015) for more details on how radiative trapping can be taken into account.
(b)
Dipole moments from Schöier et al. (2005).
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