Source selection

gapmoe conditions source-distance density on the observed source population. PreRunner enables the genulens source-selection calculation by default, so rho.dat contains the rhoD_S columns used by the histogram backend.

An gapmoe.Isochrone can apply a fixed source selection:

source = gapmoe.Isochrone(
    reference_band="Imag",
    color_bands=("Vmag", "Imag"),
    magnitude_range=(15.0, 21.0),
    color_range=(0.5, 3.0),
)

Alternatively, evaluate the event prior conditional on current measured photometry by passing named magnitudes to model.log_density:

model.log_density(
    theta,
    context={"thS": theta_star_mas},
    magnitudes={"Imag": i_s, "Vmag": v_s},
)

This is a conditional event density. Use model.log_joint_density when the source-photometry factor itself belongs in the target density.

model.source_radius and model.log_theta_star_density expose the source population summaries associated with the same CMD model.