Description

Python package for reading and analyzing halo/galaxy catalogs (generated from Rockstar or AHF) and merger trees (generated from ConsistentTrees).

Requirements

python 3, numpy, scipy, h5py, matplotlib

This package also requires the utilities/ Python package for various utility functions.

Contents

halo_analysis

halo_io.py

• read halo files, convert from text to hdf5 format, assign particle species to dark-matter halos

halo_plot.py

• analyze and plot halos/galaxies

halo_select.py

• select halos from large simulations for generating initial conditions for zoom-in

tutorials

halo_tutorial.ipynb

• Jupyter notebook tutorial for using this package

data

snapshot_times.txt

• example file for storing information about snapshots: scale-factors, redshifts, times, etc

Units

Unless otherwise noted, this package stores all quantities in (combinations of) these base units

• mass [M_sun]
• position [kpc comoving]
• distance, radius [kpc physical]
• time [Gyr]
• temperature [K]
• magnetic field [Gauss]
• elemental abundance [linear mass fraction]

These are the common exceptions to those standards

• velocity [km/s]
• acceleration [km/s / Gyr]
• gravitational potential [km^2 / s^2]
• rates (star formation, cooling, accretion) [M_sun / yr]
• metallicity (if converted from stored massfraction) [log10(mass_fraction / mass_fraction_solar)], using Asplund et al 2009 for Solar

Installing

The easiest way to install this packages and all of its dependencies is by using pip:

python -m pip install halo_analysis

Alternately, and especially if you want to ensure that you have the latest version, you can clone and install from bitbucket, in one of two ways:

using HTTPS:

git clone https://awetzel@bitbucket.org/awetzel/gizmo_analysis.git

or using SSH:

git clone git@bitbucket.org:awetzel/gizmo_analysis.git

Then do one of the following:

1. either point your PYTHONPATH to this repository (and also install and point PYTHONPATH to the utilities/ repository that it depends on)

2. or build and install this project via pip by going inside the top-level halo_analysis/ directory and doing:

python -m pip install .

Using

Once installed, you can use individual modules like this:

import halo_analysis as halo
halo.io

Citing

If you use this package, please cite it, along the lines of: 'This work used HaloAnalysis (http://ascl.net/2002.014), which first was used in Wetzel et al. 2016 (https://ui.adsabs.harvard.edu/abs/2016ApJ...827L..23W).'