Multiple Misaligned Outflows and Warped Accretion Flows in the Proto-multiple System Per-emb-8 and 55

Abstract

To investigate the formation process of multiple systems, we have analyzed the Atacama Large Millimeter/submillimeter Array archival data of the 1.3 mm continuum, ^12 CO (2-1) and C ^18 O (2-1) emission in a proto-multiple system consisting of a Class 0 protostar Per-emb-8 and a Class I protobinary Per-emb-55 A and B . The 1.3 mm continuum emission is likely to primarily trace their protostellar disks, and the Keplerian disk rotation is observed in Per-emb-8 and Per-emb-55 A in the emission lines. In Per-emb-8, we identify two arm-like structures with a length of ∼1000 au connecting the eastern and western of its disk in the continuum and C ^18 O emission. Our analysis suggests that these arm-like structures are most likely infalling flows. In the ^12 CO emission, we discover a second bipolar outflow associated with Per-emb-8. The two bipolar outflows in Per-emb-8 are possibly launched along the normal axes of the misaligned inner and outer parts of its warped protostellar disk. In Per-emb-55, we find that the red- and blueshifted lobes of its bipolar outflow are misaligned by 90°. The presence of the warped disk, multiple misaligned outflows, and asymmetric infalling flows suggest complex dynamics in proto-multiple systems, and these could be related to the tidal interactions between the companions and/or the turbulent environments forming this proto-multiple system.

Keywords

• Protostars
• Protoplanetary disks
• Young stellar objects
• Stellar accretion disks
• Star formation
• Circumstellar disks