Different Modes of Star Formation II: Gas Accretion Phase of Initially Subcritical Star-Forming Clouds

Abstract

The accretion phase of star formation is investigated in magnetically-dominated clouds that have an initial subcritical mass-to-flux ratio. We employ nonideal magnetohydrodynamic simulations that include ambipolar diffusion and ohmic dissipation. During the early prestellar phase the mass-to-flux ratio rises toward the critical value for collapse, and during this time the angular momentum of the cloud core is reduced significantly by magnetic braking. Once a protostar is formed in the core, the accretion phase is characterized by the presence of a small amount of angular momentum but a large amount of magnetic flux in the near-protostellar environment. The low angular momentum leads to a very small (or even nonexistent) disk and weak outflow, while the large magnetic flux can lead to an interchange instability that rapidly removes flux from the central region. The effective magnetic braking in the early collapse phase can even lead to a counter-rotating disk and outflow, in which the rotation direction of the disk and outflow is opposite to that of the infalling envelope. The solutions with a counter-rotating disk, tiny disk, or nonexistent disk (direct collapse) are unique outcomes that are realized in collapse from magnetically-dominated clouds with an initial subcritical mass-to-flux ratio.

arXiv commentAccepted for publication in MNRAS

References in corpus (66)

• Planck intermediate results. XXXV. Probing the role of the magnetic field in the formation of structure in molecular clouds
• The Burst Mode of Protostellar Accretion
• The Physics of Star Formation
• Protostellar disk formation and transport of angular momentum during magnetized core collapse
• A study of high velocity molecular outflows with an up-to-date sample
• Outflows and Jets from Collapsing Magnetized Cloud Cores
• On Why Disks Generate Magnetic Towers and Collimate Jets
• Electric charging of dust aggregates and its effect on dust coagulation in protoplanetary disks
• Disk formation during collapse of magnetized protostellar cores
• Mechanism of Magnetic Flux Loss in Molecular Clouds
• Ambipolar diffusion in low-mass star formation. I. General comparison with the ideal MHD case
• Collapse of Rotating Magnetized Molecular Cloud Cores and Mass Outflows
• Formation of a Keplerian disk in the infalling envelope around L1527 IRS: transformation from infalling motions to Kepler motions
• Radiation Magnetohydrodynamic Simulations of Protostellar Collapse: Non-Ideal Magnetohydrodynamic Effects and Early Formation of Circumstellar Disks
• Formation Process of the Circumstellar Disk: Long-term Simulations in the Main Accretion Phase of Star Formation
• Recurrent Planet Formation and Intermittent Protostellar Outflows Induced by Episodic Mass Accretion
• Magnetic Fields and Rotations of Protostars
• Magnetic fields during the early stages of massive star formation - I. Accretion and disk evolution
• Directions of Outflows, Disks, Magnetic Fields, and Rotation of YSOs in Collapsing Molecular Cloud Cores
• Disk-Driven Rotating Bipolar Outflow in Orion Source I
• Effects of Ohmic and ambipolar diffusion on the formation and evolution of the first cores, protostars and circumstellar discs
• Magnetically Aligned Velocity Anisotropy in the Taurus Molecular Cloud
• Evolution of Protostellar Outflow around Low-mass Protostar
• Conditions for Circumstellar Disk Formation: Effects of Initial Conditions and Sink Treatment
• Does Magnetic Field-Rotation Misalignment Solve the Magnetic Braking Catastrophe in Protostellar Disk Formation?
• Collapse and Fragmentation of Rotating Magnetized Clouds. I. Magnetic Flux - Spin Relation
• Bridging the gap: disk formation in the Class 0 phase with ambipolar diffusion and Ohmic dissipation
• Bimodality of circumstellar disk evolution induced by Hall current
• ALMA Observations of the Transition from Infall Motion to Keplerian Rotation around the Late-phase Protostar TMC-1A
• Decoupling of Magnetic Fields in Collapsing Protostellar Envelopes and Disk Formation and Fragmentation
• Grand Design Spiral Arms in A Young Forming Circumstellar Disk
• Disk Formation in Magnetized Clouds Enabled by the Hall Effect
• Protostellar birth with ambipolar and ohmic diffusion
• Formation and survival of Population III stellar systems
• First MHD Simulation of Collapse and Fragmentation of Magnetized Molecular Cloud Cores
• A Sub-arcsecond Survey Toward Class 0 Protostars in Perseus: Searching for Signatures of Protostellar Disks
• Evolution of Rotating Molecular Cloud Core with Oblique Magnetic Field
• Observations of Infalling and Rotational Motions on a 1,000-AU Scale around 17 Class 0 and 0/I Protostars: Hints of Disk Growth and Magnetic Braking?
• Circumstellar disks and outflows in turbulent molecular cloud cores: possible formation mechanism for misaligned systems
• The impact of the Hall effect during cloud core collapse:implications for circumstellar disk evolution
• Protostellar Accretion Flows Destabilized by Magnetic Flux Redistribution
• Magnetically Controlled Spasmodic Accretion During Star Formation. II. Results
• Dynamical Collapse of Nonrotating Magnetic Molecular Cloud Cores: Evolution Through Point-Mass Formation
• ALMA observations of a high-density core in Taurus: dynamical gas interaction at the possible site of a multiple star formation
• ALMA resolves the hourglass magnetic field in G31.41+0.31
• The First Two Thousand Years of Star Formation
• Protostellar Jets Enclosed by Low-velocity Outflows
• Line Polarization of Molecular Lines at Radio Frequencies: The case of DR21(OH)
• Magnetic fields in the infrared dark cloud G34.43+0.24
• Two Extreme Young Objects in Barnard 1-b
• Accretion Phase of Star Formation in Clouds with Different Metallicities
• Disc formation and fragmentation using radiative non-ideal magnetohydrodynamics
• Magnetic Flux Expulsion in Star Formation
• The Co-evolution of Disk and Star in Embedded Stages: The Case of the Very Low-mass Protostar
• Origin of Misalignments: Protostellar Jet, Outflow, Circumstellar Disc, and Magnetic Field
• On the origin of magnetic fields in stars
• The Rotating Outflow, Envelope and Disk in Class-0/I protostar [BHB2007] 11 in the Pipe Nebula
• Warm CO gas generated by possible turbulent shocks in a low-mass star-forming dense core in Taurus
• Dependence of Hall Coefficient on Grain Size and Cosmic Ray Rate and Implication for Circumstellar Disk Formation
• ALMA observations of the Th 28 protostellar disk - A new example of counter-rotation between disk and optical jet
• Extremely Dense Cores associated with Chandra Sources in Ophiuchus A: Forming Brown Dwarfs Unveiled?
• Different Modes of Star Formation: Gravitational Collapse of Magnetically Subcritical Cloud
• 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
• Protostellar Evolution in Serpens Main: Possible Origin of Disk-Size Diversity
• Possible Counter Rotation between the Disk and Protostellar Envelope around the Class I Protostar IRAS 04169+2702
• First clear detection of the CCS Zeeman splitting toward the pre-stellar core, Taurus Molecular Cloud-1

Cited by in corpus (11)

• Formation and evolution of protostellar accretion discs. II. From 3D simulation to a simple semi-analytic model of Class 0/I discs
• Formation and evolution of protostellar accretion discs. I. Angular-momentum budget, gravitational self-regulation, and numerical convergence
• The Interplay between Ambipolar Diffusion and Hall Effect on Magnetic Field Decoupling and Protostellar Disc Formation
• Failed and delayed protostellar outflows with high mass accretion rates
• Exponentially amplified magnetic field eliminates disk fragmentation around the Population III protostar
• Twin Jets and Close Binary Formation
• Impact of Magnetic Braking on High-mass Close Binary Formation
• Discovery of Asymmetric Spike-like Structures of the 10 au Disk around the Very Low-luminosity Protostar Embedded in the Taurus Dense Core MC 27/L1521F with ALMA
• Dust enrichment and growth in the earliest stages of protoplanetary disk formation
• Dense Molecular Ring-like structure in gaseous CO depletion region G34.74-0.12
• ALMA Band 9 CO(6--5) Reveals a Warm Ring Structure Associated with the Embedded Protostar in the Cold Dense Core MC 27/L1521F