Diff for "VALD3_van_der_Waals" - VALD Documentation

Differences between revisions 1 and 6 (spanning 5 versions)

van der Waals damping parameter describes broadening of spectral lines due collisions with neutral particles, e.g. Hydrogen atoms. In VALD3 it can have three values:

if 0: it is not known;

if <0: log γ₆ in units of rad/(s·N_H) at l0000 K (where N_H is the number density of neutral Hydrogen atoms in 1/cm³);

if >0 : two parameters as defined in Barklem et al. 2000A&AS..142..467. Integer part is cross-section σ, fractional part is velocity parameter α.

ValdWiki: VALD3_van_der_Waals (last edited 2024-09-18 13:40:50 by NikolaiPiskunov)

-  ⇤ ← Revision 1 as of 2024-09-17 08:57:19 → 
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  Editor: NikolaiPiskunov
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+   ← Revision 6 as of 2024-09-18 13:40:50 → ⇥
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  Editor: NikolaiPiskunov
  Comment:
-Deletions are marked like this.
+Additions are marked like this.
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-if <0: log &gamma;_6 in units of 1/(s*NH) at l0000 K (where NH is the number density of neutral Hydrogen atoms);
+if <0: log γ,,6,, in units of rad/(s&middot;N,,H,,) at l0000 K (where N,,H,, is the number density of neutral Hydrogen atoms in 1/cm^3^);
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-if >0 : two parameters as defined in Barklem et al. [[https://www.aanda.org/articles/aa/pdf/2002/15/aah3335.pdf|2000A&AS..142..467]]. Integer part is cross-section &sigma;, fractional part is velocity parameter &alpha;.
+if >0 : two parameters as defined in Barklem et al. [[https://www.aanda.org/articles/aa/pdf/2002/15/aah3335.pdf|2000A&AS..142..467]]. Integer part is cross-section σ, fractional part is velocity parameter α.