Multi-wavelength Analysis of Galaxy Physical Properties


MAGPHYS - Multi-wavelength Analysis of Galaxy Physical Properties - is a self-contained, user-friendly model package to interpret observed spectral energy distributions of galaxies in terms of galaxy-wide physical parameters pertaining to the stars and the interstellar medium, following the approach described in da Cunha, Charlot & Elbaz (2008), MNRAS 388, 1595.

The analysis of the spectral energy distribution (SED) of an observed galaxy with MAGPHYS is done in two steps:

  1. 1.The assembly of a comprehensive library of model SEDs at the same redshift and in the same photometric bands as the observed galaxy, for wide ranges of plausible physical parameters pertaining to the stars and interstellar medium.

  1. 2.The build-up of the marginalized likelihood distribution of each physical parameter of the observed galaxy, through the comparison of the observed SED with all the models in the library.

The MAGPHYS package is intended to be user-friendly. The code can run by simply following the installation instructions given in the documentation, and by editing two input files. No previous knowledge of the language in which the code is written (Fortran77) is required.

Using the links below you can download the full MAGPHYS package, the documentation containing instructions on how to install and use MAGPHYS on your UNIX machine, and the MNRAS da Cunha, Charlot & Elbaz (2008) paper.

For enquiries and feedback about MAGPHYS, do not hesitate to contact us

[Elisabete da Cunha, Swinburne & Stéphane Charlot, IAP].

© 2015 E. da Cunha & S. Charlot


     MAGPHYS package [you need about 5 GB of disk space]
                                       latest update 11/05/2012 - new filter files: including WISE filters
    NEW! Updated filter file [contains 422 filters]
    Replace these files onto your MAGPHYS directory and compile the code.
    latest update 05/08/2015 

     MAGPHYS documentation [PDF] 
     MNRAS paper [PDF]

    Recommended: Stellar libraries with the 2003 version of the Bruzual & Charlot models
     [BC03 libraries: about 3 GB] Works the same way as with the CB07 libraries. Extract binary files, place in MAGPHYS directory, and replace OptiLIB*cb07* with OptiLIB*bc03* in the .magphys_tcshrc file. Then follow instructions in the documentation.


    NEW! MAGPHYS HIGHZ extension: magphys_highz.tar.gz
   Includes new star formation histories, new dust priors and radio component as           described in da Cunha et al. (2015). Recommended for fitting high-redshift (z>1) sources.
If you use this code in your publication, please cite MAGPHYS (da Cunha et al. 2008) with the HIGHZ extension (da Cunha et al. 2015).
 This should work just like the original MAGPHYS package (please see original documentation; experience with the original MAGPHYS package is advisable; please contact Elisabete da Cunha if you encounter any problems.)
latest update 11/09/2015 [minor bugs with Makefile and scripts fixed]

MAGPHYS is optimized to derive statistical constraints of fundamental parameters related to star formation activity and dust content (e.g. star formation rate, stellar mass, dust attenuation, dust temperatures) of large samples of galaxies using a wide range of multi-wavelength observations. See for example da Cunha, Charlot & Elbaz (2008) for an application to the analysis of the Spitzer Infrared Nearby Galaxy Survey (SINGS; Kennicutt et al. 2003).

A Bayesian approach is used to interpret the SEDs all the way from the ultraviolet/optical  to the far-infrared. A similar approach has been previously used mostly to interpret optical galaxy spectra from the ultraviolet to the near-infrared, i.e. not including the dust emission (e.g. Kauffmann et al. 2003; Gallazzi et al. 2005; Salim et al. 2007).

MAGPHYS presents several key advantages over other existing models:

  1. the mid- and far-infrared dust emission of galaxies is computed consistently with the (attenuated) stellar emission at ultraviolet, optical and near-infrared emission by means of a simple energy balance argument;

  1. the model is both simple and versatile enough that it can be used to efficiently interpret multi-wavelength observations of large samples containing thousands of galaxies;

  1. it provides confidences ranges in parameter estimates and can reveal potential degeneracies in the determination of model parameters.