Dr. Omar López
Cruz.
Instituto Nacional de Astrofísica, Óptica y Electrónica,
Tonantzinltla, Puebla.
Fossil groups
exhibit extended X-ray halos similar to those in poor clusters; however,
in the optical they show a dominant luminous elliptical galaxy surrounded
by fainter companions, tantamount to Bautz-Morgan I, I-II clusters.
As anticipated in dynamical studies and high resolution numerical simulations,
it has been suggested that fósil groups could be the end-product
of the collapse of dense groups or poor clusters. We have cross-matched
the SDSS and the ROSAT All-Sky Survey to search for fossil groups using
National Virtual Observatory (NVO) technologies (e.g., OpenSkyQuery
& SkyView).
We have found
a large number of fossil groups candidates, some of them have been included
in a XMM-Newton observing proposal, in order to analyze in more detail
the extended X-ray emission. We present preliminary results based on
the analysis of archival data.