Thermal gas pressure
Pressure is used in isobaric models. For isochoric models, thermal pressure is computed by the code.
Typical values: 1E3 - 1E8 K cm-3
Scaling factor of the ISRF on the observer side of the cloud.
This radiation field is isotropic whereas a stellar spectrum is modeled as a beam radiation field.
ISRF follows the prescription of Mathis, Mezger, Panagia, 1983, A & A, 128, 212
AVmax
Size of the cloud expressed as a visual extinction
Unit: magnitude