Table 2
Observed spectral-line transitions and observational parameters.
| Transition | ν | Eu/kB | n crit | HPBW | η MB | T sys | PWV | Channel spacinga | τ int | rms | |
| [MHz] | [K] | [cm-3] | [′′] | [K] | [mm] | [kHz] | [km s-1] | [min] | [mK] | ||
|
|
|||||||||||
| C17O(2−1) | 224 714.199b | 16.2 | 2.1 × 104 | 27.8 | 0.75 | 168–208 | 1.0–2.1 | 76.3 | 0.1 | 9 | 27–34 |
| N2D+(3−2) | 231 321.912c | 22.2 | 3.0 × 106 | 27.0 | 0.75 | 204–228 | 1.0–2.1 | 76.3 | 0.1 | 9–15 | 30–36 |
| N2H+(3−2) | 279 511.832c | 26.8 | 5.2 × 106 | 22.3 | 0.74 | 161–164 | ~0.2 | 76.3 | 0.08 | 4.2–4.8 | 38–41 |
Notes.Columns (2–4) give the rest frequencies of the observed transitions (ν), their upper-state energies (Eu/kB, where kB is the Boltzmann constant), and critical densities (see text for details). Columns (5–12) give the APEX beamsize (HPBW) and the main-beam efficiency (ηMB) at the observed frequencies, the SSB system temperatures during the observations (Tsys on a TMB scale, see text), the amount of PWV, channel widths (both in kHz and km s-1) of the original data, the on-source integration times per position (τint), and the 1σ rms noise levels at the smoothed resolution.
The original channel spacings. The final spectra were Hanning-smoothed which divides the number of channels by two.
From Ladd et al. (1998).
From Pagani et al. (2009).
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