Evidence of Grain Alignment by Magnetically Enhanced Radiative Torques from Multiwavelength Dust Polarization Modeling of HL Tau

Abstract

Atacama Large Millimeter/Submillimeter Array (ALMA) has revolutionized the field of dust polarization in protoplanetary disks across multiple wavelengths. Previous observations and empirical modeling suggested multiple mechanisms of dust polarization toward HL Tau, including grain alignment and dust scattering. However, a detailed modeling of dust polarization based on grain alignment physics is not yet available. Here, using our updated POLARIS code, we perform numerical modeling of dust polarization arising from both grain alignment by Magnetically Enhanced Radiative Torque (MRAT) mechanism and self-scattering to reproduce the HL Tau polarization observed at three wavelengths 0.87, 1.3, and 3.1mm. Our modeling results show that the observed multi-wavelength polarization could be reproduced only when large grains contain embedded iron inclusions and those with slow internal relaxation must have wrong internal alignment (i.e., the grain's major axis parallel to its angular momentum). The abundance of iron embedded inside grains in the form of clusters is constrained to be $\gtrsim 16$%, and the number of iron atoms per cluster is $N_{\mathrm{cl}}\sim 9\times 10^2$. Maximum grain sizes probed at wavelengths $\lambda$ = 0.87, 1.3, and 3.1mm are constrained at $\sim$ 60, 80, and 90$\mu$m, respectively.

Published in ApJ

References in corpus (52)

• Interstellar Dust Grains
• First Results from High Angular Resolution ALMA Observations Toward the HL Tau Region
• Radiative torques: Analytical Model and Basic Properties
• Dust and Gas in the disc of HL Tauri: Surface density, dust settling, and dust-to-gas ratio
• Gaps, Rings, and Non-Axisymmetric Structures in Protoplanetary Disks - From Simulations to ALMA Observations
• The Disk Substructures at High Angular Resolution Project (DSHARP): V. Interpreting ALMA maps of protoplanetary disks in terms of a dust model
• On the Evolutionary Status of Class I Stars and Herbig-Haro Energy Sources in Taurus-Auriga
• Radiative Torques on Interstellar Grains: II. Grain Alignment
• Millimeter-wave polarization of protoplanetary disks due to dust scattering
• TADPOL: A 1.3 mm Survey of Dust Polarization in Star-forming Cores and Regions
• Magnetorotational Instability Driven Accretion in Protoplanetary Disks
• Radiative torque alignment: Essential Physical Processes
• Radiative transfer with POLARIS: I. Analysis of magnetic fields through synthetic dust continuum polarization measurements
• The Radial Distribution of Dust Particles in the HL Tau Disk from ALMA and VLA Observations
• A unified model of grain alignment: radiative alignment of interstellar grains with magnetic inclusions
• The evidence of radio polarization induced by the radiative grain alignment and self-scattering of dust grains in a protoplanetary disk
• Radiative grain alignment in protoplanetary disks: Implications for polarimetric observations
• Spatially Resolved Magnetic Field Structure in the Disk of a T Tauri Star
• ALMA Reveals Transition of Polarization Pattern with Wavelength in HL Tau's Disk
• Velocity Gradients as a Tracer for Magnetic Fields
• Grain size constraints on HL Tau with polarization signature
• Subsonic Mechanical Alignment of Irregular Grains
• Grain alignment induced by radiative torques: effects of internal relaxation of energy and complex radiation fields
• Do Proto-Jovian Planets Drive Outflows?
• Grain Alignment and Polarized Emission from Magnetized T Tauri Disks
• Scattering-Produced (Sub)millimeter Polarization in Inclined Disks: Optical Depth Effects, Near-Far Side Asymmetry, and Dust Settling
• ALMA's Polarized View of 10 Protostars in the Perseus Molecular Cloud
• Submillimeter and Far-Infrared Polarimetric Observations of Magnetic Fields in Star-Forming Regions
• Polarization of Dust Emission in Clumpy Molecular Clouds and Cores
• HL Tau disk in HCO+ (3-2) and (1-0) with ALMA: gas density, temperature, gap, and one-arm spiral
• Alignment of Dust with Magnetic Inclusions: Radiative Torques and Superparamagnetic Barnett and Nuclear Relaxation
• Resolving the Circumstellar Disk of HL Tauri at Millimeter Wavelengths
• Dust Polarization Toward Embedded Protostars in Ophiuchus with ALMA. III. Survey Overview
• Does HL Tau Disk Polarization in ALMA Band 3 Come from Radiatively Aligned Grains?
• On Internal and External Alignment of Dust Grains in Protostellar Environments
• Porous Dust Particles in Protoplanetary Disks: Application to the HL Tau Disk
• The properties of the inner disk around HL Tau: Multi-wavelength modeling of the dust emission
• Millimeter-wave polarization due to grain alignment by the gas flow in protoplanetary disks
• Alignment and rotational disruption of dust
• Dust Polarization in Four Protoplanetary Disks at 3 mm: Further Evidence of Multiple Origins
• Impact of Differential Dust Settling on the SED and Polarization: Application to the Inner Region of the HL Tau Disk
• Self-scattering of non-spherical dust grains
• Magnetically driven outflows from Jovian circum-planetaryaccretion disks
• Effects of grain alignment with magnetic fields on grain growth and the structure of dust aggregates
• Polarized emission by aligned grains in the Mie regime : application to protoplanetary disks observed by ALMA
• Physical Modeling of Dust Polarization from Magnetically Enhanced Radiative Torque (MRAT) Alignment in Protostellar Cores with POLARIS
• B-fields And dust in interstelLar fiLAments using Dust POLarization (BALLAD-POL): I. The massive filament G11.11-0.12 observed by SOFIA/HAWC+
• Modeling of the ALMA HL Tau Polarization by Mixture of Grain Alignment and Self-scattering
• (Sub)millimeter Dust Polarization of Protoplanetary Disks from Scattering by Large Millimeter-Sized Irregular Grains
• Self-scattering in protoplanetary disks with dust settling
• The Mechanical Alignment of Dust (MAD) I: On the spin-up process of fractal grains by a gas-dust drift
• Thermal Emission and Scattering by Aligned Grains: Plane-Parallel Model and Application to Multiwavelength Polarization of the HL Tau Disk

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• Synthetic Modelling of Polarized Dust Emission in Intermediate-Mass YSOs: I: Constraining the Role of Iron Inclusions and Inelastic Relaxation on Grain Alignment with ALMA Polarization
• Grain alignment and dust evolution physics with polarisation (GRADE-POL). I. Dust polarisation modelling for isolated starless cores