About SNCosmo

Package Features

  • SN models: Synthesize supernova spectra and photometry from SN models.
  • Fitting and sampling: Functions for fitting and sampling SN model parameters given photometric light curve data.
  • Dust laws: Fast implementations of several commonly used extinction laws; can be used to construct SN models that include dust.
  • I/O: Convenience functions for reading and writing peculiar data formats used in other packages and getting dust values from SFD (1998) maps.
  • Built-in supernova models such as SALT2, MLCS2k2, Hsiao, Nugent, PSNID, SNANA and Whalen models, as well as a variety of built-in bandpasses and magnitude systems.
  • Extensible: New models, bandpasses, and magnitude systems can be defined, using an object-oriented interface.

Relation to other SN cosmology software

There are several other publicly available software packages for supernova cosmology. These include (but are not limited to) snfit (SALT fitter), SNANA and SNooPy (or snpy).

  • snfit and SNANA both provide functionality overlapping with this package to some extent. The key difference is that these packages provide several (or many) executable applications, but do not provide an API for writing new programs building on the functionality they provide. This package, in contrast, provides no executables; instead it is a library of functions and classes designed to provide the building blocks commonly used in many aspects of SN analyses.
  • SNooPy (or snpy) is also a Python library for SN analysis, but with a (mostly) different feature set. SNCosmo is based on spectral timeseries models whereas SNooPy is more focussed on models of light curves in given bands.

The name SNCosmo

A natural choice, “snpy”, was already taken (SNooPy) so I tried to be a little more descriptive. The package is really specific to supernova cosmology, as it doesn’t cover other types of supernova science (radiative transfer simulations for instance). Hence “sncosmo”.


Alphabetical by last name:

  • Stephen Bailey
  • Kyle Barbary
  • Tom Barclay
  • Rahul Biswas
  • Matt Craig
  • Ulrich Feindt
  • Brian Friesen
  • Danny Goldstein
  • Saurabh Jha
  • Steve Rodney
  • Caroline Sofiatti
  • Rollin C. Thomas
  • Michael Wood-Vasey