Table 1. Column densities and abundance ratios for the isomers of HC3N and HC5N towards TMC-1 and IRC+10216.
| Molecule | TMC-1 | IRC+10216 |
|---|---|---|
| N(HC3N) | (2.3±0.2)×1014 | (4.5±0.2)×1014 |
| N(HCCNC) | (3.0±0.3)×1012 | (1.1±0.1)×1012 |
| N(HNCCC) | (5.2±0.3)×1011 | (3.4±0.2)×1011 |
| N(HC5N) | (1.8±0.2)×1014 | (4.2±0.4)×1014 b |
| N(HC4NC) | (3.0±0.7)×1011 | ≤2.1×1011 |
| N(HNC5) | ≤1.5×1011 | ≤1.1×1011 |
| N(HC7N) | (6.4±0.2)×1013 | (1.9±0.2)×1014 c |
| N(HC6NC) | ≤9.0×1010 | ≤2.0×1011 |
| N(HC3N)/N(HCCNC) | 77.0±8.0 | 392±22 |
| N(HC3N)/N(HNCCC) | 442.0±70.0 | 1305±45 |
| N(HCCNC)/N(HNCCC) | 5.8±1.0 | 4.0±0.9 |
| N(HC5N)/N(HC4NC) | 600±70.0 | ≥2000 |
| N(HC5N)/N(HNC5) | ≥1200 | ≥3800 |
| N(HC4NC)/N(HNC5) | ≥2 | ≥1.9 |
| N(HC7N)/N(HC6NC) | ≥710.0 | ≥950 |
| N(HC3N)/N(HC5N) | 1.3±0.2 | 1.1±0.2 |
| N(HC5N)/N(HC7N) | 2.8±0.3 | 2.2±0.5 |
Notes.
(a)
All column densities are given in units of cm–2.
(b)
For IRC+10216, we adopted the value derived by Pardo et al. (2020), which corresponds to the gas component with T rot=10.1 K. A second component, with similar column density, was found for high-J levels with a T rot=24.5 K.
(c)
For IRC+10216, we adopted the value derived by Pardo etal. (2020), which corresponds to the gas component with T rot=16.8 K. A second component, with a column density 2.5 lower, was found for high-J levels with a T rot=31.6 K.