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Accueil > Séminaires > Archive des séminaires d’Utinam > Archive des séminaires d’astrophysique (jusqu’en 2011) > 2010

Extragalactic research with the Virtual Observatory

par Edith Burgey -

Mardi 19 janvier 2010

Igor Chilingarian

Observatoire de Strasbourg

Résumé :

Nowadays, following years of technological development, Virtual Observatory standards, resources, and services became powerful enough to help astronomers making real science on everyday basis. An astronomer is able to combine ``online’’ VO-enabled parts with ``offline’’ research stages including dedicated data processing and analysis, observations, numerical simulations. I will present three VO-science projects combining VO and non-VO blocks, all of them resulted in peer-reviewed publications.

(1) We used a VO-fed workflow to automatically analyse a large amount of HST data and discovered a population of compact elliptical (M32-like) galaxies in nearby clusters. Some of these galaxies were later observed with the 6-m telescope to confirm their membership in the clusters, some others were confirmed by analysing archival spectra also available in the VO. We have performed dedicated numerical simulations to model their origin by the tidal stripping, demonstrating the importance of this galaxy evolution mechanism.

(2) We have cross-identified two large sources of photometric data : SDSS DR7 (optical), UKIDSS DR5 (NIR) and compiled a homogeneous catalogue of spectral energy distributions of nearby galaxies (0.03<0.6). We extracted the data for the spectroscopically confirmed galaxies and fitted their SDSS DR7 spectra to obtain stellar population parameters, velocity dispersion and residual emission line fluxes of some 190000 galaxies. By using VO tools and technologies, all the computational part of the study was completed in a week after the UKIDSS Data Release 5.

(3) The GalMer database is a part of the Horizon project, providing access to a library of TreeSPH simulations of galaxy interactions. We have developed a set of value-added tools related for data visualization and post-processing with available VO-interfaces, including the spectrophotometric modelling of galaxy properties, making GalMer the most advanced resource providing online access to the results of numerical simulations. These tools allow direct comparison of simulations with imaging and spectroscopic observations.