Table 6.
Results of the sensitivity study.
| Mock spectrum | S/N | log n(4He) | log n(3He) |  |
|---|---|---|---|---|
| Model I+ | 23 |  |
 |
 |
| Model I+ | 100 |  |
 |
0.01 ± 0.01 |
| Model I+ | 200 |  |
−2.84 ± 0.01 | 0.01 ± 0.01 |
| Model I+ | 300 |  |
−2.85 ± 0.02 | 0.01 ± 0.01 |
| EC 03263-6403a | 23 |  |
 |
0.01 ± 0.01 |
| Model II+ | 84 |  |
 |
 |
| Model II+ | 100 |  |
−2.56 ± 0.06 | 0.14 ± 0.06 |
| Model II+ | 200 | −3.38 ± 0.02 | −2.57 ± 0.02 | 0.15 ± 0.06 |
| Model II+ | 300 | −3.35 ± 0.02 | −2.57 ± 0.01 | 0.17 ± 0.06 |
| BD+48° 2721a | 84 |  |
 |
 |
| Model III- | 25 | −2.77 ± 0.04 | −2.70 ± 0.03 | 0.86 ± 0.30 |
| HE 1047-0436a | 25 | −2.76 ± 0.04 | −2.72 ± 0.03 | 0.91 ± 0.32 |
Notes. 1σ statistical single parameter errors on log n(4He) and log n(3He) are given. The systematic uncertainties are ± 0.10 in all cases. The given uncertainties on n(4He)/n(3He) result from statistical and systematic errors, for which Gaussian error propagation was used. From Table 4: Model I+ (Teff = 29 000 K, log(g) = 5.21, log n(4He) = −4.75, log n(3He) = −2.85, He I 6678 Å included), Model II+ (20 700 K, 4.81, −3.34, −2.57, He I 6678 Å included), and Model III-(29 800 K, 5.65, −2.76, −2.72, He I 6678 Å excluded).
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