.. _physics-stellarPopulationSelector:

Stellar Population Selectors
============================

Class providing selectors for stellar populations---algorithms that choose the appropriate :galacticus-class:`stellarPopulationClass` object to associate with a star formation event given the current star formation rate, the component metallicity, and the galaxy component. Different implementations may always return the same (fixed) stellar population, or may select a metal-poor population at low metallicities to represent Population III stars or a starburst population at high star formation rates, allowing heterogeneous stellar populations within a single galaxy.

**Default implementation:** ``stellarPopulationSelectorFixed``

Methods
-------

``select`` → ``class(stellarPopulationClass)``
   Return the appropriate :galacticus-class:`stellarPopulationClass` object for a star formation event given the current star formation rate, the elemental abundances of the fuel, and the galaxy component type (disk, spheroid, etc.).

   * ``double precision , intent(in ) :: rateStarFormation``

   * ``type (abundances ), intent(in ) :: abundances_``

   * ``class (nodeComponent), intent(in ) :: component``

``isStarFormationRateDependent`` → ``logical``
   Return true if the selection of stellar population is dependent on star formation rate.

.. _physics-stellarPopulationSelectorDiskSpheroid:

``stellarPopulationSelectorDiskSpheroid``
-----------------------------------------

A stellar population selector class which selects a different population for disks and spheroids, irrespective of other physical conditions. The populations to use are specified by the ``[stellarPopulationDisk]`` and ``[stellarPopulationSpheroid]`` parameters.

.. _physics-stellarPopulationSelectorFixed:

``stellarPopulationSelectorFixed``
----------------------------------

A stellar population selector class which selects a fixed population irrespective of physical conditions.

**(Default implementation)**