Description
This update adds the NonLTELineGasMix class, which describes the material properties related to selected transitions in selected molecules and atoms. For each supported species, the current implementation includes a number of rotational energy levels (quantum number J) at the base vibrational level (quantum number v=0) for molecules and electronic energy levels and hyperfine split levels for atoms, and supports the allowed transitions between these levels. Vibrational energy levels and the corresponding rovibrational transitions may be added later. The class properties allow configuring the species and the number of transitions to be considered.
For each supported transition, the emission luminosity and absorption opacity in a given cell are determined from the gas properties defined in the input model and the local radiation field calculated by the simulation. The class performs an iterative, non-LTE calculation including the effects of collisional transitions (excitation and de-excitation with one or more types of interaction partners) and photonic transitions (spontaneous emission, absorption, and induced emission). This allows establishing the energy level distribution (population) for a wide range of material densities and radiation fields.
The current implementation supports a fictive test molecule (called TT for our purposes), the Hydroxyl radical (OH), the Formyl cation (HCO+), Carbon monoxide (CO), atomic carbon (C), and ionized carbon (C+), each with a selection of relevant energy levels and transitions.
For more information about configuring a simulation with this material mix, refer to the documentation of the NonLTELineGasMix class.
Motivation
This update allows combining non-LTE line transfer calculations with the full power of SKIRT, such as post-processing arbitrary imported 3D models that include both dust and gas.
Tests
With this new class, SKIRT properly reproduces the results provided by van Zadelhoff et al. 2002 for benchmark problems 1 and 2. These problems respectively employ the fictive test molecule (TT) and Formyl (HCO+).
Important note: the class has not yet been tested for the other supported species. Use with extreme care!
Description This update adds the
NonLTELineGasMixclass, which describes the material properties related to selected transitions in selected molecules and atoms. For each supported species, the current implementation includes a number of rotational energy levels (quantum number J) at the base vibrational level (quantum number v=0) for molecules and electronic energy levels and hyperfine split levels for atoms, and supports the allowed transitions between these levels. Vibrational energy levels and the corresponding rovibrational transitions may be added later. The class properties allow configuring the species and the number of transitions to be considered.For each supported transition, the emission luminosity and absorption opacity in a given cell are determined from the gas properties defined in the input model and the local radiation field calculated by the simulation. The class performs an iterative, non-LTE calculation including the effects of collisional transitions (excitation and de-excitation with one or more types of interaction partners) and photonic transitions (spontaneous emission, absorption, and induced emission). This allows establishing the energy level distribution (population) for a wide range of material densities and radiation fields.
The current implementation supports a fictive test molecule (called TT for our purposes), the Hydroxyl radical (OH), the Formyl cation (HCO+), Carbon monoxide (CO), atomic carbon (C), and ionized carbon (C+), each with a selection of relevant energy levels and transitions.
For more information about configuring a simulation with this material mix, refer to the documentation of the
NonLTELineGasMixclass.Motivation This update allows combining non-LTE line transfer calculations with the full power of SKIRT, such as post-processing arbitrary imported 3D models that include both dust and gas.
Tests With this new class, SKIRT properly reproduces the results provided by van Zadelhoff et al. 2002 for benchmark problems 1 and 2. These problems respectively employ the fictive test molecule (TT) and Formyl (HCO+).
Important note: the class has not yet been tested for the other supported species. Use with extreme care!