The dust disk and companion of the nearby AGB star L2 Puppis (Kervella et al.)

Vol. 578
In section 6. Interstellar and circumstellar matter

The dust disk and companion of the nearby AGB star L2 Puppis. SPHERE/ZIMPOL polarimetric imaging at visible wavelengths

This paper presents polarimetric imaging of the dust disk and companion of the nearby AGB star L2 Puppis from the newly commissioned VLT instrument SPHERE/ZIMPOL. These data were taken as part of the science verification of this instrument. The signature of a three-dimensional structure is clearly observed in the linear polarization map. The inner rim of the disk can be identified at a distance of 6AU from the AGB star. The ZIMPOL intensity images in the V and R bands also reveal a close companion at a projected separation of 2 AU. Interactions between the inner binary system and the disk apparently form spiral structures that propagate along the orthogonal axis to the disk to form streamers. Two dust plumes that propagate orthogonally to the disk are also detected, originate in the inner stellar system, and are maybe related to the interaction of the wind of the two stars with the material in the disk. Based on the morphology of the envelope of L2 Pup, the authors propose that this star is in the early stages of forming a bipolar planetary nebula.