Mergers and interactions in Sloan Digital Sky Survey type 2 quasars at z∼ 0.3-0.4. SDSS J143027.66-005614.8: a case study★

Abstract

We present a compilation of HST images of 58 luminous SDSS type 2 AGNs at\n0.3<z<0.4. 42 of them are type 2 quasars, which are a good representation of\nall optically selected SDSS type 2 quasars in this range. We find that the\nmajority of the host galaxies are ellipticals (30/42 or 71%). This is\nconsistent with studies of radio loud and radio quiet type 1 quasars which show\nthat their host galaxies are in general ellipticals. A significant fraction of\ntype 2 quasars (>25/42 or >59%) show clear signatures of morphological\ndisturbance which are in most cases identified with merger/interaction\nprocesses. We discuss this in the context of related works on type 2 quasars\nand powerful radio galaxies.\n We study in detail the particular case of the radio quiet type 2 quasar SDSS\nJ143027.66-005614.8 at z=0.32 based on VLT, HST and SDSS imaging and\nspectroscopic data. We discuss the global properties of the object in the\ncontext of theoretical and observational studies of galaxy mergers/interactions\nand their role in the triggering of the nuclear and star formation activities\nin the most luminous active galaxies.\n