Barak 0.3.2 documentation

barak.abundances.calc_abund

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barak.abundances.calc_abund

barak.abundances.calc_abund(X, Y, logNX, logNY)[source]

Find the abundance relative to solar given two elements and their column densities.

Parameters :

X, Y : str

Element identifiers (for example ‘C’, ‘Si’, ‘Mg’).

logNX : array_like, shape (N,)

log10 of element X column density in cm^-2.

logNY : array_like, shape (N,)

log10 of element Y column density in cm^-2.

Returns :

abundance_ratio : ndarray, shape (N,)

Abundance ratio relative to solar, [X/Y].

Notes

The abundance ratio is defined:

[X/Y] = log10 (n_X / n_Y) - log10 (n_Xsun / n_Ysun)

Where N_Xsun / N_Ysun is the ratio of the number density of species X to species Y for ‘proto-solar’ abundances (See Lodders 2003, ApJ, 591, 1220). For example, if [X/Y] = 0, it has the same abundance as the proto-solar values. If [X/Y] = 1, then ten times larger, [X/Y] = -1, then ten times smaller.

If Y is hydrogen, then this estimates the metallicity.

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