Open Access
Table 1
Observational parameters.
| Line | Frequency(a) | δv | Trms(b) | θMB(c) | ηMB |
|---|---|---|---|---|---|
| (MHz) | (m s−1) | (mK) | |||
| Institut de Radio-Astronomie Millimétrique (IRAM) 30-m | |||||
| N2H+ (1–0) | 93173.764 | 31 | 22–72 | 26 | 0.85 |
| DCO+ (2–1) | 144077.282 | 41 | 28–53 | 17 | 0.80 |
| N2D+ (2–1) | 154217.181 | 38 | 25–42 | 16 | 0.78 |
| DCO+ (3–2) | 216112.582 | 68 | 48–104 | 11 | 0.66 |
| C18O (2–1) | 219560.358 | 67 | 55–123 | 11 | 0.66 |
| N2H+ (3–2) | 279511.832 | 42 | 30–68 | 9 | 0.56 |
| Green Bank Telescope (GBT) 100-m | |||||
| DCO+ (1–0) | 72039.303 | 48 | 55–98 | 11 | 0.51 |
| N2D+ (1–0) | 77109.616 | 44 | 25–30 | 10 | 0.51 |
| James Clerk Maxwell Telescope (JCMT) 15-m | |||||
| H2D+ (110–111 ) | 372421.356 | 49 | 30–52 | 13 | 0.60 |
| N2H+ (4–3) | 372672.526 | 49 | 38–58 | 13 | 0.60 |
Notes. (a)N2H+ and N2D+ frequencies are taken from Pagani et al. (2009a). The frequencies correspond to the strongest hyperfine component for each transition. (b)The rms noise is expressed in the 
scale (Kutner & Ulich 1981). (c)The beam size is the HPBW.
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.