Using the Virtual Observatory: multi-instrument, multi-wavelength study   of high-energy sources
  This paper presents a tutorial explaining the use of Virtual Observatory tools in high energy astrophysics. Most of the tools used in this paper were developed at the Strasbourg astronomical Data Center and we show how they can be applied to conduct a multi-instrument, multi-wavelength analysis of sources detected by the High Energy Stereoscopic System and the Fermi Large Area Telescope. The analysis involves queries of different data catalogs, selection and cross-correlation techniques on multi-waveband images, and the construction of high energy color-color plots and multi-wavelength spectra. The tutorial is publicly available on the website of the European Virtual Observatory project. 
S\'ebastien Derriere, Rene W. Goosmann, Caroline Bot, Fran\c{c}ois   Bonnarel
astro-ph.IM