Magnetic Spirals in Accretion Flows Originated from Misaligned Magnetic Field

Abstract

Misalignment between rotation and magnetic field has been suggested to be one type of physical mechanisms which can easen the effects of magnetic braking during collapse of cloud cores leading to formation of protostellar disks. However, its essential factors are poorly understood. Therefore, we perform a more detailed analysis of the physics involved. We analyze existing simulation data to measure the system torques, mass accretion rates and Toomre Q parameters. We also examine the presence of shocks in the system. While advective torques are generally the strongest, we find that magnetic and gravitational torques can play substantial roles in how angular momentum is transferred during the disk formation process. Magnetic torques can shape the accretion flows, creating two-armed magnetized inflow spirals aligned with the magnetic field. We find evidence of an accretion shock that is aligned according to the spiral structure of the system. Inclusion of ambipolar diffusion as explored in this work has shown a slight influence in the small scale structures but not in the main morphology. We discuss potential candidate systems where some of these phenomena could be present.

26 pages, 26 figures, 2 tables, Accepted for publication in the Astrophysical Journal

References in corpus (22)

• Array Programming with NumPy
• The VLA/ALMA Nascent Disk and Multiplicity (VANDAM) Survey of Orion Protostars. A Statistical Characterization of Class 0 and I Protostellar Disks
• A protostellar system fed by a streamer of 10,500 au length
• Gravitational collapse of magnetized clouds. I. Ideal MHD accretion flow
• Effects of Ohmic and ambipolar diffusion on the formation and evolution of the first cores, protostars and circumstellar discs
• An ALMA Survey of CO isotopologue emission from Protoplanetary Disks in Chamaeleon I
• The Ophiuchus DIsc Survey Employing ALMA (ODISEA)-III: the evolution of substructures in massive discs at 3-5 au resolution
• Magnetically self-regulated formation of early protoplanetary discs
• The Perseus ALMA Chemistry Survey (PEACHES). I. The Complex Organic Molecules in Perseus Embedded Protostars
• Gravity Driven Magnetic Field at ~1000 au Scales in High-mass Star Formation
• ALMA survey of Class II protoplanetary disks in Corona Australis: a young region with low disk masses
• Disk Formation Enabled by Enhanced Resistivity
• An ALMA Continuum Survey of Circumstellar Disks in the Upper Scorpius OB Association
• ALMA Survey of Orion Planck Galactic Cold Clumps (ALMASOP) II. Survey overview: a first look at 1.3 mm continuum maps and molecular outflows
• Simulating hydromagnetic processes in star formation: introducing ambipolar diffusion into an adaptive mesh refinement code
• Substructure Formation in a Protostellar Disk of L1527 IRS
• A Pseudodisk Threaded with a Toroidal and Pinched Poloidal Magnetic Field Morphology in the HH 211 Protostellar System
• The VLA/ALMA Nascent Disk and Multiplicity (VANDAM) Survey of Orion Protostars I. Identifying and Characterizing the Protostellar Content of the OMC2-FIR4 and OMC2-FIR3 Regions
• ALMA Survey of Orion Planck Galactic Cold Clumps (ALMASOP): I. Detection of New Hot Corinos with ACA
• Resolved molecular line observations reveal an inherited molecular layer in the young disk around TMC1A
• A Tight Relation between Spiral Arm Pitch Angle and Protoplanetary Disk Mass
• Time Evolution of 3D Disk Formation with Misaligned Magnetic Field and Rotation Axes