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Table 2

Initial fractional abundances f0(X)a of parent species, relative to H2, for the O-rich AGB star, IK Tau.

No. Species f0(X) Comment

1 He 1.7(–1) Solar abundanceb
2 CO 2.0(–4) Observationc
3 H2O 6.6(–5) Observationd
4 N2 1.5(–4) Shock-induced non-LTE abundancee
5 NH3 2.0(–6) Observationf
6 HCN 4.4(–7) Observationc
7 CO2 4.4(–9) Shock-induced non-LTE abundancee
8 CS 8.0(–8) Observationc
9 SiS 1.1(–5) Observationc
10 SiO 1.6(–5) Observationd
11 SO 2.0(–6) Observationd
12 SO2 2.0(–6) Observationc
13 H2S 1.0(–8) Shock-induced non-LTE abundancee
14 HS 2.3(–8) Shock-induced non-LTE abundancee
15 PN 3.0(–7) Observationg
16 PO 9.0(–8) Observationg
17 HCl 3.7(–7) Shock-induced non-LTE abundancee
18 HF 7.3(–7) TE predictionhb

Notes. a(b) = a × 10b.


For species X, f0(X) = n(X)/n(H2).


See Table 6 in Decin et al. (2010b). In that work the fractional abundance was given relative to the total H-content, nH, by assuming all hydrogen is in its molecular form, H2, i.e., nH = 2n(H2).


TE prediction, assuming elemental F has the solar abundance.

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