An origin of arc structures deeply embedded in dense molecular cloud cores

Abstract

We investigated the formation of arc-like structures in the infalling envelope around protostars, motivated by the recent Atacama Large Millimeter/Submillimeter Array (ALMA) observations of the high-density molecular cloud core, MC27/L1521F. We performed self-gravitational hydrodynamical numerical simulations with an adaptive mesh refinement code. A filamentary cloud with a 0.1~pc width fragments into cloud cores because of perturbations due to weak turbulence. The cloud core undergoes gravitational collapse to form multiple protostars, and gravitational torque from the orbiting protostars produces arc structures extending up to a 1000~AU scale. As well as on a spatial extent, the velocity ranges of the arc structures, $\sim 0.5{\mathrm{km}\mathrm{s}}^{-1}$, are in agreement with the ALMA observations. We also found that circumstellar disks are often misaligned in triple system. The misalignment is caused by the tidal interaction between the protostars when they undergo close encounters because of a highly eccentric orbit of the tight binary pair.

5 pages, 4 figures, accepted for publication in MNRAS

References in corpus (4)

• Misaligned Protoplanetary Disks in a Young Binary System
• ALMA observations of a high-density core in Taurus: dynamical gas interaction at the possible site of a multiple star formation
• ALMA Observations of the T Tauri Binary System AS 205: Evidence for Molecular Winds and/or Binary Interactions
• ALMA observations of a misaligned binary protoplanetary disk system in Orion

Cited by in corpus (8)

• Seeds Of Life In Space (SOLIS): The organic composition diversity at 300--1000 au scale in Solar-type star forming regions
• FRagmentation and Evolution of dense cores Judged by ALMA (FREJA). I (Overview). Inner $\sim$1000 au structures of prestellar/protostellar cores in Taurus
• Structure of a protobinary system: an asymmetric circumbinary disk and spiral arms
• A Detached Protostellar Disk around a $\sim$0.2$M_{\odot }$ protostar in a Possible Site of a Multiple Star Formation in a Dynamical Environment in Taurus
• Twin Jets and Close Binary Formation
• Formation of the Unequal-Mass Binary Protostars in L1551 NE by Rotationally-Driven Fragmentation
• Misaligned Circumstellar Disks and Orbital Motion of the Young Binary XZ Tau
• A new formation scenario of a counter-rotating circumstellar disk: spiral-arm accretion from a circumbinary disk in a triple protostar system