class rubin_sim.maf.maf_contrib.LVDwarfsMetric(radius=2.45, distlim=None, cmd_frac=0.1, stargal_contamination=0.4, nsigma=10.0, metric_name='LVDwarfs', seed=505, **kwargs)

Bases: BaseMetric

Estimate the detection limit in total dwarf luminosity for resolved dwarf galaxies at a given distance.

This metric class uses simulated luminosity functions of dwarf galaxies with known (assumed) luminosities to estimate the detection limit (in total dwarf luminosity, M_V) for resolved dwarf galaxies at a given distance. It can be applied to either known galaxies with their discrete positions and distances, or an entire survey simulation with a fixed distance limit.

In the default use (with the KnownLvDwarfsSlicer), it returns detection limits for a catalog of known local volume dwarfs, from the Karachentsev+ catalog of nearby galaxies.

radiusfloat, default=2.45,

Radius of the field being considered (for discrete fields only). By default, UserPointSlicer uses a 2.45-deg field radius.


Distance threshold in Mpc for which to calculate the limiting dwarf detection luminosity. Only needed for healpix slicers, but required if healpix is used.

cmd_fracfloat, default=0.1,

Fraction of the total area of the color-magnitude diagram that is spanned by the tracer selection criteria. (e.g., the size of a box in color and magnitude to select RGB-star candidates)

stargal_contaminationfloat, default=0.4,

Fraction of objects in CMD selection region that are actually unresolved galaxies that were mis-classified as stars.

nsigmafloat, default=10.0,

Required detection significance to declare a simulated dwarf “detected.”

Methods Summary

run(data_slice[, slice_point])

Calculate metric values.

Methods Documentation

run(data_slice, slice_point=None)

Calculate metric values.


Values passed to metric by the slicer, which the metric will use to calculate metric values at each slice_point.

slice_pointdict or None

Dictionary of slice_point metadata passed to each metric. E.g. the ra/dec of the healpix pixel or opsim fieldId.

metricValue: int float or object

The metric value at each slice_point.