Galaxy Zoo : Dust lane early-type galaxies are tracers of recent, gas-rich minor mergers

摘要: We present the second of two papers concerning origin and evolution local early-type galaxies exhibiting dust features. use optical radio data to examine nature AGN activity in these objects, compare with carefully constructed control samples. find that lane are much more likely host emission-line than Moreover, there is a strong correlation between early-types, but not Dust show same distribution properties rich poor environments, suggesting similar triggering mechanism. By contrast, this case for early-types no These findings strongly suggest starburst systems formed gas-rich mergers. Further evidence support scenario provided by enhanced star formation black hole accretion rates objects. derive ages younger sample. therefore represent an evolutionary stage starbursting quiescent galaxies. In has already been triggered as yet completely destroyed gas reservoir required formation.