As we know the current models explain elliptical galaxies as dead galaxies, but have to say a completely different history is suggested by the images of two galaxies obtained by the MégaCam camera of the Canada-France-Hawaii Telescope (CFHT, CNRS/CNRC/University of Hawaii). All members of an international ATLAS 3D team, have shown that these two elliptical galaxies were formed from the merger of two large spiral galaxies, just 1 to 3 billion years ago. The filaments of gas and stars, which have been detected by the CFHT, form two long tails on either side of the galaxy, extending over more than one million light years whcih is more than 10 times the span of the Milky Way. It is the largest stellar structure ever detected.
The ATLAS 3D team is conducting a deep optical imaging program on a hundred or so other nearby elliptical galaxies. So if the results obtained on these first two galaxies are confirmed and if such extended stellar structures prove to be frequent, the standard model of the formation of elliptical galaxies can change.