Probing Physics and Chemistry in Circumnuclear Torus with OH

Abstract

Abstract.We observed OH maser emission at 18cm in a circumnuclear torus surrounding the center of IRAS10173+0828 using the 7 telescopes of MERLIN, together with the Lovell antenna. IRAS10173+0828 is a distant super-luminous far-infrared galaxy. The OH maser emission is remarkably narrow (FWHP = 39km s _1 ) for its strength, and the 1667 and 1665 MHz lines are well separated. The 1667 transition shows two distinct peaks displaced from one another by 100 km s~x. Using our MERLIN observational results we probe the physics in the circumnuclear torus surrounding the center of IRAS10173+0828, obtain the kinematic properties of the torus, and study the central source.