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

Abstract

Iron inclusions embedded inside dust grains play a crucial role in both internal alignment (IA) via Barnett relaxation and external alignment via the MAgnetically Enhanced RAdiative Torque (MRAT) mechanism. Moreover, inelastic relaxation is predicted to dominate over Barnett relaxation in driving the IA of micron-sized and very large grains above $10\mu m$ (VLGs). Yet, a detailed modeling of polarized thermal dust emission from Class 0/I Young Stellar Objects (YSOs) taking into account these effects and their observational constraints is still lacking. In this paper, we update the POLARIS code and use it to perform synthetic dust polarization modeling for MHD simulations of an intermediate-mass YSO. Results will be post-processed with CASA to confront ALMA polarimetric observations. We found that to reproduce the high polarization degree of $p\sim 5-30\%$ observed in protostellar envelopes by ALMA, micron-sized and VLGs must contain iron inclusions with $N_{\mathrm{cl}}\sim 5-10^3$ iron atoms per cluster, assuming $30\%$ of iron abundance locked inside dust grains under the cluster form. Inside the inner $\sim 500$ au region, inelastic relaxation must participate in driving the grain internal alignment, and grains must contain larger iron inclusions of $N_{\mathrm{cl}}\sim 10^2-10^4$ and grow beyond $\ge 10\mu m$ to reproduce $\sim 3-10\%$ of dust polarization observed by ALMA. But given such a combination, the internal alignment and MRAT efficiency acting on VLGs still decrease toward the center, inducing the decrease of $p(\%)$ with increasing gas density, reaching $p\sim 1\%$ inside the disk.

32 pages, 9 pages in Appendix, accepted to ApJ

References in corpus (53)

• A Unified Representation of Gas-Phase Element Depletions in the Interstellar Medium
• Radiative torques: Analytical Model and Basic Properties
• The evolution of amorphous hydrocarbons in the ISM: dust modelling from a new vantage point
• Tracing Magnetic Fields with Aligned Grains
• Magnetic Fields in the Formation of Sun-Like Stars
• Magnetic Braking and Protostellar Disk Formation: The Ideal MHD Limit
• Radiative torque alignment: Essential Physical Processes
• Gravitational collapse of magnetized clouds. I. Ideal MHD accretion flow
• Towards a more realistic sink particle algorithm for the RAMSES code
• The evidence of radio polarization induced by the radiative grain alignment and self-scattering of dust grains in a protoplanetary disk
• Grain growth in the envelopes and disks of Class I protostars
• ALMA Reveals Transition of Polarization Pattern with Wavelength in HL Tau's Disk
• Grain Alignment by Radiative Torques in Special Conditions and Implications
• Submillimeter polarization observation of the protoplanetary disk around HD 142527
• Interferometric observations of magnetic fields in forming stars
• Dust variations in the diffuse interstellar medium: constraints on Milky Way dust from Planck-HFI observations
• ALMA observations of dust polarization and molecular line emission from the Class 0 protostellar source Serpens SMM1
• Impact of Protostellar Outflows on Turbulence and Star Formation Efficiency in Magnetized Dense Cores
• A hidden reservoir of Fe/FeS in interstellar silicates?
• Low dust emissivities and radial variations in the envelopes of Class 0 protostars: a signature of early grain growth?
• Accretion and ejection properties of embedded protostars: the case of HH26, HH34 and HH46 IRS
• Alignment of Dust with Magnetic Inclusions: Radiative Torques and Superparamagnetic Barnett and Nuclear Relaxation
• Accretion and magnetic field morphology around Class 0 stage protostellar discs
• Probing changes of dust properties along a chain of solar-type prestellar and protostellar cores in Taurus with NIKA
• The origin of GEMS in IDPs as deduced from microstructural evolution of amorphous silicates with annealing
• Protostellar collapse simulations in spherical geometry with dust coagulation and fragmentation
• Dust Polarization Toward Embedded Protostars in Ophiuchus with ALMA. II. IRAS 16293-2422
• On Internal and External Alignment of Dust Grains in Protostellar Environments
• Intrinsic polarisation of elongated porous dust grains
• 3D magnetic field morphology of the Perseus molecular cloud
• The Link between Magnetic Fields and Cloud/Star Formation
• THEMIS 2.0: A self-consistent model for dust extinction, emission, and polarisation
• Tracing the ISM magnetic field morphology: The potential of multi-wavelength polarization measurements
• The Class 0 Protostar BHR71: Herschel Observations and Dust Continuum Models
• Observations of magnetic fields surrounding LkH$\alpha$ 101 taken by the BISTRO survey with JCMT-POL-2
• Effects of grain alignment with magnetic fields on grain growth and the structure of dust aggregates
• The JCMT BISTRO Survey: An 850/450$\mu$m Polarization Study of NGC 2071IR in OrionB
• Physical Modeling of Dust Polarization from Magnetically Enhanced Radiative Torque (MRAT) Alignment in Protostellar Cores with POLARIS
• On the magnetic field properties of protostellar envelopes in Orion
• FAUST IX. Multi-band, multi-scale dust study of L1527 IRS. Evidence for dust properties variations within the envelope of a Class 0/I YSO
• Size limit of superparamagnetic inclusions in dust grains and difficulty of magnetic grain alignment in protoplanetary disks
• Modeling of the ALMA HL Tau Polarization by Mixture of Grain Alignment and Self-scattering
• Compaction during fragmentation and bouncing produces realistic dust grain porosities in protoplanetary discs
• The Mechanical Alignment of Dust (MAD) I: On the spin-up process of fractal grains by a gas-dust drift
• Polarization from Aligned Dust Grains in the $\beta$ Pic Debris Disk
• A correlation between chemistry, polarization and dust properties in the Pipe Nebula starless core FeSt 1-457
• Physical conditions for dust grain alignment in Class 0 protostellar cores I. Observations of dust polarization and molecular irradiation tracers
• Is the mm/submm dust polarization a robust tracer of the magnetic field topology in protostellar envelopes? A model exploration
• Physical conditions for dust grain alignment in Class 0 protostellar cores II. The role of the radiation field in models aligning/disrupting dust grains
• Evidence of Grain Alignment by Magnetically Enhanced Radiative Torques from Multiwavelength Dust Polarization Modeling of HL Tau
• The Transition of Polarized Dust Thermal Emission from the Protostellar Envelope to the Disk Scale
• The origin of dust polarization in the Orion Bar
• Completing the Protostellar Luminosity Function in Cygnus-X with SOFIA/FORCAST Imaging

Cited by in corpus (2)

• Grain alignment and dust evolution physics with polarisation (GRADE-POL). I. Dust polarisation modelling for isolated starless cores
• Large Interstellar Polarisation Survey. III. Observational constraints on the structure of grains