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Home All issues Volume 525 (January 2011) A&A, 525 (2011) A77 Full HTML
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Table 6

H i and H2 column densities of the absorption components.

Label Velocity rangea NH   i/Tsb T s c N H   i d N H2 e Abs. comp.f
(km s-1) (cm-2 K-1) (K) (cm-2) (cm-2)
(1) (2) (3) (4) (5) (6) (7)
A 95.3–38.6 9.0(1.8) × 1019 43( 5) 3.9(0.9) × 1021 5.4 × 1023 [2]
B 23.2–12.9 1.5(0.5) × 1019 65(10) 1.0(0.4) × 1021 5.5 × 1022 [5, 6]
C –12.9– –33.5 8.5(2.0) × 1018 93(10) 7.9(2.0) × 1020 1.4 × 1022 [12, 13, 14, 15]
D –36.1– –51.5 1.6(0.4) × 1019 20( 3) 3.1(0.9) × 1020 2.0 × 1022 [17, 18, 19]
E –54.1– –64.4 3.0(1.0) × 1018 55( 6) 1.7(0.6) × 1020 2.6 × 1021 [21]
F –69.6– –85.0 2.6(0.7) × 1018 80( 8) 2.1(0.6) × 1020 7.1 × 1021 [22, 23, 24, 25]
G –90.2– –123.7 2.8(0.7) × 1018 43( 7) 1.2(0.4) × 1020 1.6 × 1022 [27, 28, 29, 30, 31, 32]

Notes. The numbers in parentheses are the uncertainties.

(a)

Velocity range over which the H i column density is computed.

(b)

Ratio of H i column density to spin temperature, obtained from the VLA data.

(c)

H i spin temperature derived from the Effelsberg data.

(d)

H i column density.

(e)

H2 column density derived from the H13CO+ column densities assuming the isotopic ratios listed in Col. 4 of Table 3 and an HCO+ abundance of 5 × 10-9 relative to H2.

(f)

List of the absorption components used to compute the H2 column densities, with the same numbering as in Col. 1 of Table 3.

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