vice.yields.presets.JW20.alt_cc_sr_linear
=========================================

The functional form of the alternative CCSN Sr yield explored in Johnson &
Weinberg (2020) [1]_ which is linear in metallicity :math:`Z`.

**Signature**: vice.yields.presets.JW20.alt_cc_sr_linear(Z, Z_solar = 0.014)

.. versionadded:: 1.1.0

Parameters
----------
Z : real number
	The metallicity by mass :math:`M_Z/M_\star`.
Z_solar : real number [default : 0.014]
	The metallicity by mass of the Sun. Default value is take from
	Asplund et al. (2009) [2]_.

Returns
-------
y : real number
	The IMF-averaged CCSN Sr yield as a function of metallicity Z.

Notes
-----
The yield is defined by:

.. math:: y_\text{Sr}^\text{CC} = 3.5\times10^{-8}
	\left(\frac{Z}{Z_\odot}\right)

Example Code
------------
>>> import vice
>>> from vice.yields.presets import JW20
>>> vice.yields.ccsne.settings['sr'] = JW20.alt_cc_sr_linear
>>> modified = lambda z: JW20.alt_cc_sr_linear(z, Z_solar = 0.018)
>>> vice.yields.ccsne.settings['sr'] = modified

.. [1] Johnson & Weinberg (2020), MNRAS, 498, 1364
.. [2] Asplund et al. (2009), ARA&A, 47, 481