A new formation scenario of a counter-rotating circumstellar disk: spiral-arm accretion from a circumbinary disk in a triple protostar system

Abstract

We present the evolution of rotational directions of circumstellar disks in a triple protostar system simulated from a turbulent molecular cloud core with no magnetic field. We find a new formation pathway of a counter-rotating circumstellar disk in such triple systems. The tertiary protostar forms via the circumbinary disk fragmentation and the initial rotational directions of all the three circumstellar disks are almost parallel to that of the orbital motion of the binary system. Their mutual gravito-hydrodynamical interaction for the subsequent $\sim 10^4\mathrm{yr}$ greatly disturbs the orbit of the tertiary, and the rotational directions of the tertiary disk and star are reversed due to the spiral-arm accretion of the circumbinary disk. The counter-rotation of the tertiary circumstellar disk continues to the end of the simulation ($\sim 6.4\times 10^4\mathrm{yr}$ after its formation), implying that the counter-rotating disk is long-lived. This new formation pathway during the disk evolution in Class 0/I Young Stellar Objects possibly explains the counter-rotating disks recently discovered by ALMA.

Accepted for publication in PASJ

References in corpus (13)

• SPLASH: An interactive visualisation tool for Smoothed Particle Hydrodynamics simulations
• The Disk Substructures at High Angular Resolution Project (DSHARP): IV. Characterizing substructures and interactions in disks around multiple star systems
• Misaligned Disks in the Binary Protostar IRS 43
• Misaligned Protoplanetary Disks in a Young Binary System
• Gas flow and accretion via spiral streamers and circumstellar disks in a young binary protostar
• Spiral Arms, Infall, and Misalignment of the Circumbinary Disk from the Circumstellar Disks in the Protostellar Binary System L1551 NE
• Salt, Hot Water, and Silicon Compounds Tracing Massive Twin Disks
• Formation and Early Evolution of Circumstellar Disks in Turbulent Molecular Cloud Cores
• Strongly misaligned triple system in SR 24 revealed by ALMA
• The misaligned orbit of the Earth-sized planet Kepler-408b
• An origin of arc structures deeply embedded in dense molecular cloud cores
• Star-disk alignment in the protoplanetary disks: SPH simulation of the collapse of turbulent molecular cloud cores
• Misaligned Circumstellar Disks and Orbital Motion of the Young Binary XZ Tau