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commented
1 month ago 
Build Successful! You can find a link to the downloadable artifact below.
| Name | Link |
|---|---|
| Commit | 1a5049beb7521cb7ec787d525f07dc8bea8f1965 |
| Logs | https://github.com/TeamCOMPAS/COMPAS/actions/runs/8984646371 |
| Download | https://github.com/TeamCOMPAS/COMPAS/suites/$SUITE_ID/artifacts/$ARTIFACT_ID |
Fixes an issue that manifests for low metallicities. This is a continuation of the fixes for issue https://github.com/TeamCOMPAS/COMPAS/issues/978
The problem here was that Hurley et al. 2000 has this on p29:
b47 = 1.127733ρ + 0.2344416ρ2 − 0.3793726ρ3 but the sse code has this (in zcnsts.f:
b47 = 1.127733ρ + 0.2344416ρ2 − 0.3793726ρ3 (actually, in the code it is: gbp(66) = 1.d0 - lzd(xh(77) + lzd(xh(78) + lzd*xh(79))) )
At first I thought that was just a mistake in the paper, but b[47] is only used once in the paper (eq 58, to calculate Tbl on p12), and there the equation 58 uses (1 - b[47]), so Jarrod has just put the "1.0 -" into the constant when it is calculated.
However, in the sse code, b[47] is also used to calculate the radius on the HG phase. I recently (in the fix for issue https://github.com/TeamCOMPAS/COMPAS/issues/978) added that code to COMPAS (see HG::CalculateRadiusOnPhase()), but I wasn't aware that the constant had the "1.0 -" prefix already added...
So, to keep the code looking like the paper, COMPAS uses the equation on p29 of the paper to calculate b[47], and adds the "1.0 -" prefix in the code (in CHeB::CalculateLifetimeOnBluePhase(), and now in HG::CalculateRadiusOnPhase()).