synthesizer.emission_models.stellar.multi_pacman_model

A module defining the MultiPacman emission models.

The MultiPacman models extend the Pacman models with a second escape fraction. As in Pacman, fesc is the fraction of the incident emission that escapes the photoionised region without being reprocessed. In addition, fesc_dust is the fraction of the emission reaching the ISM dust that escapes it without being attenuated.

Whether the incident emission escaping the photoionised region then sees the ISM dust is controlled by attenuate_incident_escaped. If True (the default) the escaped incident emission joins the reprocessed emission and fesc_dust applies to both. If False the escaped incident emission leaves the galaxy unattenuated (as in Pacman) and fesc_dust applies only to the reprocessed emission. With attenuate_incident_escaped=False and fesc_dust=0 the models reduce to their Pacman equivalents.

MultiPacmanEmission treats a single population of stars. BimodalMultiPacmanEmission splits the stars into young and old populations, where the young population’s reprocessed emission is also attenuated by its birth cloud before reaching the ISM. The incident emission escaping the photoionised region also escapes the birth cloud.

Example:

model = MultiPacmanEmission(
    grid,
    tau_v=0.33,
    fesc=0.1,
    fesc_dust=0.2,
    dust_curve=Calzetti2000(),
    dust_emission=Greybody(...),
)

Classes

class synthesizer.emission_models.stellar.multi_pacman_model.BimodalMultiPacmanEmission(grid, tau_v_ism='tau_v_ism', tau_v_birth='tau_v_birth', dust_curve_ism=Calzetti2000(slope=0, cent_lam=2175 Å, ampl=0, gamma=350 Å), dust_curve_birth=Calzetti2000(slope=0, cent_lam=2175 Å, ampl=0, gamma=350 Å), age_pivot=unyt_quantity(7, 'dimensionless'), dust_emission_ism=None, dust_emission_birth=None, fesc='fesc', fesc_dust='fesc_dust', fesc_ly_alpha='fesc_ly_alpha', attenuate_incident_escaped=True, label=None, stellar_dust=True, velocity_dispersion=None, **kwargs)[source]

The MultiPacman model split into young and old populations.

As MultiPacmanEmission, but the young population’s reprocessed emission is first attenuated by its birth cloud. The incident emission escaping the photoionised region also escapes the birth cloud. Every model is produced for the young population (prefixed “young_”), the old population (prefixed “old_”) and their combination (unprefixed).

This model will produce, for each of these:
  • incident, transmitted, escaped, nebular, reprocessed, intrinsic,

    dust_escaped, obscured, attenuated and emergent, as described in MultiPacmanEmission.

For the young population only:
  • young_attenuated_nebular: the reprocessed emission attenuated by

    the birth cloud.

  • young_ism_incident: the emission reaching the ISM dust (birth

    cloud attenuated + escaped), if attenuate_incident_escaped is True.

If dust emission models are given, it will also produce:

  • young_dust_emission_birth: the emission from birth cloud dust.

  • young_dust_emission_ism: the emission from ISM dust heated by the

    young population.

  • young_dust_emission, old_dust_emission and dust_emission: the

    emission from dust.

  • young_total, old_total and total: the emergent + dust emission.

class synthesizer.emission_models.stellar.multi_pacman_model.MultiPacmanEmission(grid, tau_v='tau_v', dust_curve=PowerLaw(slope=-1.0), dust_emission=None, fesc='fesc', fesc_dust='fesc_dust', fesc_ly_alpha='fesc_ly_alpha', attenuate_incident_escaped=True, label=None, stellar_dust=True, velocity_dispersion=None, **kwargs)[source]

The MultiPacman model for a single stellar population.

This is the Pacman model with separate escape fractions for the photoionised region (fesc) and the ISM dust (fesc_dust). See the module docstring for how they combine.

This model will produce:
  • incident: the stellar emission incident onto the photoionised

    region.

  • transmitted: the incident emission transmitted through the

    photoionised region.

  • escaped: the incident emission escaping the photoionised region.

  • nebular: the emission from the photoionised region.

  • reprocessed: the transmitted + nebular emission.

  • intrinsic: the reprocessed + escaped emission.

  • dust_escaped: the emission escaping the ISM dust.

  • obscured: the emission obscured by the ISM dust.

  • attenuated: the obscured emission attenuated by the ISM dust.

  • emergent: the emission leaving the galaxy (attenuated +

    dust_escaped, plus escaped if attenuate_incident_escaped is False).

If a dust emission model is given, it will also produce:

  • dust_emission: the emission from dust.

  • total: the emergent + dust emission.