vice.yields.ccsne.settings

The VICE dataframe: global settings for CCSN yields

For each chemical element, this object stores the current core collapse supernova (CCSN) nucleosynthetic yield setting. See Notes below for mathematical details.

Note

Modifying yield settings through this dataframe is equivalent to going through the vice.elements module.

Indexing

  • str [case-insensitive]elemental symbols

    This dataframe must be indexed by the symbol of an element recognized by VICE as it appears on the periodic table.

Item Assignment

For each chemical element, the CCSN yield can be assigned either:

  • real number : denotes a constant, metallicity-independent yield.

  • <function>Mathematical function describing the yield.

    Must accept the metallicity by mass \(Z\) as the only parameter.

Functions

  • keys

  • todict

  • restore_defaults

  • factory_settings

  • save_defaults

Notes

In all instances, VICE approximates CCSN enrichment to occur instantaneously according to an IMF-averaged yield. As with all other yields in VICE, these are net rather than gross yields in that they quantify only the mass of a given element which is newly produced. In one- and multi-zone chemical evolution models, the rate of enrichment due to CCSNe proceeds according to the following equation:

\[\dot{M}_\text{CC} = y_\text{CC}\dot{M}_\star\]

where \(y_\text{CC}\) is the yield assigned to a given element and \(\dot{M}_\star\) is the star formation rate. For single stellar populations, the mass of some element produced by all CCSNe associated with that stellar population is given by:

\[M = y_\text{CC}M_\star\]

where \(M_\star\) is the total initial mass of the stellar population. For further details, see VICE’s science documentation: https://vice-astro.readthedocs.io/en/latest/science_documentation/index.html.

Example Code

>>> import vice
>>> vice.yields.ccsne.settings["fe"] = 0.001
>>> vice.yields.ccsne.settings["Fe"]
        0.001
>>> vice.yields.ccsne.settings["FE"] = 0.0012
>>> vice.yields.ccsne.settings["fe"]
        0.0012
>>> def f(z):
        return 0.005 + 0.002 * (z / 0.014)
>>> vice.yields.ccsne.settings["fe"] = f
>>> vice.yields.ccsne.settings["FE"]
        <function __main__.f(z)>