The-wiZZ: Clustering redshift estimation for everyone
  We present The-wiZZ, an open source and user-friendly software for estimating
the redshift distributions of photometric galaxies with unknown redshifts by
spatially cross-correlating them against a reference sample with known
redshifts. The main benefit of The-wiZZ is in separating the angular pair
finding and correlation estimation from the computation of the output
clustering redshifts allowing anyone to create a clustering redshift for their
sample without the intervention of an "expert". It allows the end user of a
given survey to select any sub-sample of photometric galaxies with unknown
redshifts, match this sample's catalog indices into a value-added data file,
and produce a clustering redshift estimation for this sample in a fraction of
the time it would take to run all the angular correlations needed to produce a
clustering redshift. We show results with this software using photometric data
from the Kilo-Degree Survey (KiDS) and spectroscopic redshifts from the Galaxy
and Mass Assembly (GAMA) survey and the Sloan Digital Sky Survey (SDSS). The
results we present for KiDS are consistent with the redshift distributions used
in a recent cosmic shear analysis from the survey. We also present results
using a hybrid machine learning-clustering redshift analysis that enables the
estimation of clustering redshifts for individual galaxies. The-wiZZ can be
downloaded at http://github.com/morriscb/The-wiZZ/.
