Table 3
Abundances and abundance ratios of nitrogen hydrides at steady state predicted using several chemical networks.
| Observationsa | Models | |||||
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| N ( cm-2) | N/NH | Dislaire et al. (2012) b | This workc | Flower et al. (2006a)d | ||
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| NH | 2.2 ± 0.8(14) | 7.3 ± 4.5(−9) | 4.3(−10) | 1.2(−8) | 1.3(−9) | |
| NH2(o) | 5.0 ± 0.9(13) | 1.7 ± 0.9(−9) | – | 2.5(−9) | 2.0(−9) | |
| NH2(p) | – | – | – | 1.1(−9) | 2.0(−9) | |
| NH2 | 7.5 ± 3.0(13) | 2.5 ± 1.6(−9) | 8.2(−11) | 3.6(−9) | 4.0(−9) | |
| NH3(o) | – | – | – | 5.8(−9) | 2.5(−9) | |
| NH3(p) | – | – | – | 8.6(−9) | 7.3(−9) | |
| NH3 | 1.4 ± 1.0(15) | 4.7 ± 4.1(−8) | 7.5(−10) | 1.4(−8) | 9.8(−9) | |
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| NH2:NH | 0.34 ± 0.18 | 0.2 | 0.3 | 3.1 | ||
| NH3:NH | 6.4 ± 5.2 | 1.7 | 1.2 | 7.5 | ||
| NH:NH2:NH3 | 3:1:19 | 5:1:9 | 3:1:3 | 0.3:1:2.5 | ||
Notes. Constant physical conditions were adopted: Tkin=10 K, nH = 104 cm-3, ζ = 1.3 × 10-17 s-1. Numbers in parentheses are powers of ten.
Based on Hily-Blant et al. (2010a) and revised as described in Appendix A. For each species, N is the total column density. The adopted value of NH = 3.0 ± 1.5 × 1022 cm-2.
Updated version of the osu.09.2008 network used in Dislaire et al. (2012), who adopted C/O = 0.67 and [S]tot = 1.5 × 10-5.
Our network with the parameters of our best model: C/O = 0.8 (or [O]tot=1.04 × 10-4) and [S]tot=8 × 10-8.
Network from Flower et al. (2006a) adopting the parameters of our best model.
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