ASPECT - A SPEctra Clustering Tool

for the exploration of large spectroscopic surveys

Analysing the output from surveys is an important challenge in modern science. This, however, is not an easy task for a voluminous dataset.

We developed the new software tool ASPECT which is based on a novel approach for analysing large spectra databases. The heart of the software is a Kohonen self-organizing map (SOM) that is able to cluster up to several hundred thousand spectra. The resulting two-dimensional SOM of topologically ordered spectra allows the user to browse and navigate through a huge data pool and helps him to gain a deeper insight into underlying relationships between spectral features and other physical properties.

ASPECT supports the visual analysis of the resulting SOM of spectra by the option to blend in individual object properties (e.g., redshift, signal-to-noise ratio, spectral type, morphological type). In addition, the tool provides algorithms for the selection of spectral types, e.g., local difference maps which reflect the deviations of all spectra from a given input spectrum.

Contact: Aick in der Au (aick -ät-, Helmut Meusinger (meus -ät-

Last update: 14 February 2017, Helmut Meusinger