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Table 4
Model input parameters.
| Parameter | Value or range |
|---|---|
| Radiation field: | |
| CR ionization rate ζCR | 5(− 17) s−1 |
| X-ray ionization rate ζX | 0 s−1 |
| Extinction at the cloud edge Av | 100mag |
| UV photodesorption yield | 1(−05) |
| Grain properties: | |
| Grain radius rg | 0.1 μm |
| Dust density ρd | 3 g cm−3 |
| Gas-to-dust mass ratio η | 150 |
| Surface diffusivity EDiff/EBind | 0.4 |
| Mantle composition | MgxFex−1SiO4 (olivine) |
| Pre-HMC stages | |
| IRDC stage (a) | |
| Inner radius rin | 12 700 au |
| Outer radius rout | 0.5 pc |
| Temperature T0 at rin | 11.3 K |
| Temperature power-law index q | 0.0 (isothermal) |
| Density n0 at rin | 1.4(5) cm−3 |
| Density power-law index p | 1.5 |
| τIRDC | 16 500 yr |
| HMC stage: | |
| Inner radius rin | 50−700 au |
| Inner radius step Δrin | 50 au |
| Outer radius rout | 7 000−31 000 au |
| Outer radius step Δrout | 2 000 au |
| Temperature power-law index q | 0.41 |
| Temperature T0 at rin (b) |  |
| Density power-law index p | 1.0−2.5 |
| Density power-law index step Δp | 0.1 |
| τHMC | 10−105 yr |
| ΔτHMC | 100 logarithmic steps |
Notes. a(b) = a × 10b. (a) Taken from Gerner et al. (2015). (b)Constraint from the observations described in Sect. 3.3.1.
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