kimmy.js

Javascript version of kimmy, Galactic chemical evolution in python

Overview

This is a stand-alone Javascript version of the kimmy Python library for Galactic chemical evolution. kimmy.js replicates all of the functionality in kimmy.py as of 01/17/2020.

Author

Jo Bovy (University of Toronto): bovy - at - astro - dot - utoronto - dot - ca

Usage

Load the library, e.g., from jsDelivr using

<script src="https://cdn.jsdelivr.net/npm/@jobovy/kimmy"></script>

for the latest version or specify the version with (update 1.1.2 to later versions as necessary)

<script src="https://cdn.jsdelivr.net/npm/@jobovy/kimmy@1.1.2"></script>

Currently, the only implemented feature is a simple one-zone chemical model with two elements O (for oxygen) and Fe (for iron). Initialize this model as

var oz= new Kimmy.OneZone();

then for example compute the evolution of the default model and obtain the [O/Fe] vs. [Fe/H] sequence, do

// Define a logarithmically-spaced array of times to compute the evolution at
var Ntimes= 51;
var min_age= 0.001; // Gyr
var max_age= 12.5; // Gyr
var log10_min_age= Math.log10(min_age);
var log10_max_age= Math.log10(max_age);
var times= Array.apply(null, {length: Ntimes}).map(Number.call, Number).map\
(x => log10_min_age+x*(log10_max_age-log10_min_age)/(Ntimes-1.)).map(x => Math.pow(10.,x));
// Obtain the evolution
var OFe= oz.O_Fe(times);
var FeH= oz.Fe_H(times);

You can also compute the distribution of [Fe/H], [O/H], and [O/Fe], for example as

var FeH_dist= oz.Fe_H_DF(0.1,-3.5,1.0); // inputs are dFeH, FeHmin, FeHmax

This returns a list with the element being the [Fe/H] bins and the second the distribution.

You can directly update the main parameters of the model and the model will be re-computed. For example, to change the outflow parameter eta do

oz.eta= 4.
// Re-obtain the evolution
var OFe= oz.O_Fe(times);
var FeH= oz.Fe_H(times);

Keep in mind that once you change a parameter, it remains changed in the model.

Publishing a new version of this package

Follow the following steps:

• Update the version in package.json
• Create a new git tag for this version: git tag vX.X.X
• Package up for npm: npm pack, check that no extraneous files are included
• Publish to npm: npm publish
• Done!