Transition from ordered pinched to warped magnetic field on a 100 au scale in the Class 0 protostar B335

Abstract

We present our observational results of the 0.87 mm polarized dust emission in the Class 0 protostar B335 obtained with the Atacama Large Millimeter/submillimeter Array (ALMA) at a 0.2" (20 au) resolution. We compared our data at 0.87 mm with those at 1.3 mm from the ALMA archive. The observed polarization orientations at the two wavelengths are consistent within the uncertainty, and the polarization percentages are systematically higher at 1.3 mm than 0.87 mm by a factor of ~1.7, suggesting that the polarized emission originates from magnetically aligned dust grains. We inferred the magnetic field orientations from the observed polarization orientations. We found that the magnetic field changes from ordered and highly pinched to more complicated and asymmetric structures within the inner 100 au scale of B335, and the magnetic field connects to the center along the equatorial plane as well as along the directions which are ~40-60 degrees from the equatorial plane. We performed non-ideal MHD simulations of collapsing dense cores. We found that similar magnetic field structures appear in our simulations of dense cores with the magnetic field and rotational axis slightly misaligned by 15 degrees but not in those with the aligned magnetic field and rotational axis. Our results suggest that the midplane of the inner envelope within the inner 100 au scale of B335 could be warped because of the misaligned magnetic field and rotational axis, and the magnetic field could be dragged by the warped accretion flows.

11 pages, 6 figures, Accepted by ApJ

References in corpus (27)

• Theory of Star Formation
• Radiative torques: Analytical Model and Basic Properties
• Magnetic Fields in the Formation of Sun-Like Stars
• Magnetic Braking and Protostellar Disk Formation: The Ideal MHD Limit
• Signs of Early-Stage Disk Growth Revealed with ALMA
• 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
• Decoupling of Magnetic Fields in Collapsing Protostellar Envelopes and Disk Formation and Fragmentation
• ALMA observations of dust polarization and molecular line emission from the Class 0 protostellar source Serpens SMM1
• Radiation Magnetohydrodynamics Simulation of Proto-Stellar Collapse: Two-Component Molecular Outflow
• Unveiling the Role of the Magnetic Field at the Smallest Scales of Star Formation
• ALMA Results of the Pseudodisk, Rotating disk, and Jet in Continuum and HCO+ in the Protostellar System HH 212
• Discovery of a Hot Corino in the Bok Globule B335
• There is no magnetic braking catastrophe: Low-mass star cluster and protostellar disc formation with non-ideal magnetohydrodynamics
• Dust Polarization Toward Embedded Protostars in Ophiuchus with ALMA. III. Survey Overview
• Spitzer Observations of Bok Globule B335: Isolated Star Formation Efficiency and Cloud Structure
• The impact of the Hall effect during cloud core collapse:implications for circumstellar disk evolution
• Characterizing magnetic field morphologies in three Serpens protostellar cores with ALMA
• Accretion and magnetic field morphology around Class 0 stage protostellar discs
• The First Two Thousand Years of Star Formation
• On the Role of Pseudodisk Warping and Reconnection in Protostellar Disk Formation in Turbulent Magnetized Cores
• Dust Polarization Toward Embedded Protostars in Ophiuchus with ALMA. II. IRAS 16293-2422
• Kinematics around the B335 protostar down to au scales
• Disc formation and fragmentation using radiative non-ideal magnetohydrodynamics
• Resolving Linear Polarization due to Emission and Extinction of Aligned Dust Grains on NGC1333 IRAS4A with JVLA and ALMA
• Herbig-Haro flows in B335
• JCMT POL-2 and ALMA polarimetric observations of 6000-100 au scales in the protostar B335: linking magnetic field and gas kinematics in observations and MHD simulations

Cited by in corpus (8)

• The JCMT BISTRO survey: alignment between outflows and magnetic fields in dense cores/clumps
• The Interplay between Ambipolar Diffusion and Hall Effect on Magnetic Field Decoupling and Protostellar Disc Formation
• Models of Rotating Infall for the B335 Protostar
• Constraining the magnetic field properties of Bok globule B335 using SOFIA/HAWC+
• FERIA: Flat Envelope Model with Rotation and Infall under Angular Momentum Conservation
• The Transition of Polarized Dust Thermal Emission from the Protostellar Envelope to the Disk Scale
• A Survey of Magnetic Field Properties in Bok Globules
• Effects of magnetic field orientations in dense cores on gas kinematics in protostellar envelopes