BSM physics with top quarks in the ATLAS experiment

Studies of the top quark offer an interesting window on possible Beyond the Standard Model physics at the LHC. The ATLAS measurement program on 2010 and 2011 includes searches for the decay of a heavy resonance into a ttbar pair. The 2010 result allows to derive limits on the production of several high mass phenomena. Some candidate events for highly boosted top quark decays will be presented and the particular topology that results is discussed. We furthermore present measurements of jet mass and substructure on an inclusive jet sample, that are vital to commission the reconstruction of highly boosted top quarks.