vice.yields.agb.settings

The VICE dataframe: global yield settings for AGB stars

For each chemical element, this object stores the current asymptotic giant branch (AGB) star nucleosynthetic yield setting. See Notes below for mathematical details.

New in version 1.2.0: In earlier versions, functions and classes within VICE accepted keyword arguments or attributes which encoded which model table of yields to adopt. This same functionality can be achieved by assigning a string as the yield setting for specific elements.

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 AGB star yield can be assigned either:

  • str [case-insensitive]Adopt values published by a given study

    Keywords correspond to yields calculated on a table of progenitor masses and metallicities which can be adopted directly.

    • “cristallo11” : Cristallo et al. (2011, 2015) [1] [2]

    • “karakas10” : Karakas (2010) [3]

    • “ventura13” : Ventura et al. (2013) [4]

    • “karakas16”Karakas & Lugaro (2016) [5] ; Karakas et al. (2018)

      [6]

    New in version 1.3.0: The “ventura13” and “karakas16” yields models were introduced in version 1.3.0.

  • <function>Mathematical function describing the yield

    Must accept progenitor zero age main sequence mass in \(M_\odot\) as the first parameter and the metallicity by mass \(Z\) as the second.

Functions

  • keys

  • todict

  • restore_defaults

  • factory_settings

  • save_defaults

Notes

VICE defines the yield from AGB stars as the fraction of a star’s initial mass which is processed into some element. 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. For a star of mass \(M_\star\), the mass of the element ejected to the ISM, not counting previously produced nucleosynthetic material, is given by:

\[M = y_\text{AGB}(M_\star, Z_\star) M_\star\]

where \(y_\text{AGB}\) is the yield and \(Z_\star\) is the initial metallicity of the star.

This definition is retained in one- and multi-zone chemical evolution models as well. 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.agb.settings["n"] = "cristallo11"
>>> vice.yields.agb.settings["N"]
        "cristallo11"
>>> vice.yields.agb.settings["N"] = "karakas10"
>>> vice.yields.agb.settings["n"]
        "karakas10"
>>> def f(m, z):
        return 0.001 * m * (z / 0.014)
>>> vice.yields.agb.settings["n"] = f
>>> vice.yields.agb.settings["N"]
        <function __main__.f(z)>