A Slowly Expanding Disk and Fast Bipolar Outflow from the S Star π1 Gruis

摘要: We study the molecular outflow of nearby evolved S star π1 Gru. imaged in CO J = 2-1 and dust continuum with Submillimeter Array. The emission was detected over a very broad velocity width ~90 km s-1. Our high-resolution images show that at low velocities (≤15 s-1) is elongated east-west high (≥25 displaced north (at redshifted velocities) south (blueshifted center as defined by source. model spatial-kinematic structure low-velocity flared disk central cavity radius 200 AU an expansion 11 s-1, inclined 55° to our line sight. attribute high-velocity component bipolar emerges perpendicular this up ~45 This may play important role shaping gas envelope previously ejected AGB thus produce morphology when object evolves into proto-planetary nebula.