Terapix (archive) -

07/12/2007 The picture below shows the result of modeling galaxy profiles with the latest EFIGI version of SExtractor on a set of 45 galaxies with negative spirality indices, randomly chosen in the PGC-1.3 g-band sample (click the picture to zoom).

Galaxies are modeled as the sum of a bulge, a disk, a bar and spiral arms (19 parameters) convolved with the local PSF. There are still some difficulties to fit the inner parts of the spiral structure. No cleaning with nfigi has yet been applied to the images, and only the largest objects were fitted. The fitting residuals are shown below (contrast doubled).

In the same section

Shapelets for MATLAB

March 18th, 2001

Data decomposition using PCA / D�composition des donn�es par ACP

First results of decomposition of galaxies using Principal Components Analysis.
Premiers r�sultats de d�composition d'images de galaxies par Analyse en Composantes Principales.

May 18th, 2003

Operateurs morphologiques et Analyse en Composantes Principales

Presentation de la chaine de traitement effectue sur les images de galaxies pour calculer une base de Kerhunen-Loeve.

June 7th, 2004

Data decomposition using PCA / D�composition des donn�es par ACP

Results of decomposition of galaxies using Principal Components Analysis after a cleaning process of images.
R�sultats de d�composition d'images de galaxies par Analyse en Composantes Principales apr�s un nettoyage des images.

June 13th, 2004

Data decomposition using PCA / D�composition des donn�es par ACP

Results of galaxy image decomposition using Principal Components Analysis. This third version completes the cleaning process and uses new data (RC3).
R�sultats de d�composition d'images de galaxies par Analyse en Composantes Principales. Cette troisi�me version compl�te le processus de nettoyage et utilise de nouvelles donn�es (RC3).

June 23rd, 2004

Data decomposition using PCA / D�composition des donn�es par ACP

Results of decomposition of galaxies using Principal Components Analysis with a new data set and new transformations.
R�sultats de d�composition d'images de galaxies par Analyse en Composantes Principales avec un nouveau jeu de donn�es et de nouvelles transformations.

February 16th, 2003

PGC 1.3 g-band pretreated data / Donn�es pr�trait�es du PGC 1.3 en bande g

May 18th, 2005

Cleaning and inpainting / Nettoyage et inpainting

Presentation of the new cleaning method (november 2006). Presentation de la nouvelle methode de nettoyage (novembre 2006).

November 14th, 2005

Unsupervised classification / Classification non supervisee

This experiment is a segmentation of the data space using a decision tree on PCA.

November 28th, 2005

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