Self-scattering in protoplanetary disks with dust settling

Abstract

Scattering of re-emitted flux is considered to be at least partially responsible for the observed polarisation in the (sub-)millimetre wavelength range of several protoplanetary disks. Although the degree of polarisation produced by scattering is highly dependent on the dust model, early studies investigating this mechanism relied on the assumption of single grain sizes and simple density distribution of the dust. However, in the dense inner regions where this mechanism is usually most efficient, the existence of dust grains with sizes ranging from nanometres to millimetres has been confirmed. Additionally, the presence of gas forces larger grains to migrate vertically towards the disk midplane, introducing a dust segregation in the vertical direction. Using polarisation radiative transfer simulations, we analyse the dependence of the resulting scattered light polarisation at 350 $\mu$m, 850 $\mu$m, 1.3 mm, and 2 mm on various parameters describing protoplanetary disks, including the effect of dust grain settling. We find that the different disk parameters change the degree of polarisation mostly by affecting the anisotropy of the radiation field, the optical depth, or both. It is therefore very challenging to deduce certain disk parameter values directly from polarisation measurements alone. However, assuming a high dust albedo, it is possible to trace the transition from optically thick to optically thin disk regions. The degree of polarisation in most of the considered disk configurations is lower than what is found observationally, implying the necessity to revisit models that describe the dust properties and disk structure.

arXiv commentaccepted by A&A, 7 pages, 8 figures

References in corpus (26)

• Dust Grain Size Distributions and Extinction in the Milky Way, LMC, and SMC
• Resolved Images of Large Cavities in Protoplanetary Transition Disks
• Consistent dust and gas models for protoplanetary disks. I. Disk shape, dust settling, opacities, and PAHs
• Modeling optical properties of cosmic dust grains using a distribution of hollow spheres
• Millimeter-wave polarization of protoplanetary disks due to dust scattering
• Radiative transfer with POLARIS: I. Analysis of magnetic fields through synthetic dust continuum polarization measurements
• The evidence of radio polarization induced by the radiative grain alignment and self-scattering of dust grains in a protoplanetary disk
• Opacity of fluffy dust aggregates
• Inclination-Induced Polarization of Scattered Millimeter Radiation from Protoplanetary Disks: The Case of HL Tau
• 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
• Gas vs dust sizes of protoplanetary disks: effects of dust evolution
• ALMA observations of polarized emission toward the CW Tau and DG Tau protoplanetary disks: constraints on dust grain growth and settling
• Protoplanetary Disks in $\rho$ Ophiuchus as Seen From ALMA
• ALMA observations of polarization from dust scattering in the IM Lup protoplanetary disk
• Scattering-Produced (Sub)millimeter Polarization in Inclined Disks: Optical Depth Effects, Near-Far Side Asymmetry, and Dust Settling
• Submillimetre dust polarisation and opacity in the HD163296 protoplanetary ring system
• Two Different Grain Size Distributions within the Protoplanetary Disk around HD 142527 Revealed by ALMA Polarization Observation
• ALMA Dust Polarization Observations of Two Young Edge-on Protostellar Disks
• Mass constraints for 15 protoplanetary disks from HD 1-0
• Radial variations in grain sizes and dust scale heights in the protoplanetary disk around HD 163296 revealed by ALMA polarization observation
• An Ordered Magnetic Field in the Protoplanetary Disk of AB Aur Revealed by Mid-Infrared Polarimetry
• Multiple scattering of polarized radiation by non-spherical grains: first results
• Self-scattering of non-spherical dust grains
• Polarization reversal of scattered thermal dust emission in protoplanetary disks at (sub-)mm wavelengths
• Characterization of mid-infrared polarization due to scattering in protoplanetary disks

Cited by in corpus (13)

• The young protostellar disk in IRAS16293-2422 B is hot and shows signatures of gravitational instability
• Impact of Differential Dust Settling on the SED and Polarization: Application to the Inner Region of the HL Tau Disk
• Constraining the magnetic field properties of Bok globule B335 using SOFIA/HAWC+
• Self-scattering on large, porous grains in protoplanetary disks with dust settling
• Thermal Emission and Scattering by Aligned Grains: Plane-Parallel Model and Application to Multiwavelength Polarization of the HL Tau Disk
• Three-dimensional continuum radiative transfer of polarized radiation in exoplanetary atmospheres
• Is the mm/submm dust polarization a robust tracer of the magnetic field topology in protostellar envelopes? A model exploration
• Sub-mm/mm optical properties of real protoplanetary matter derived from Rosetta/MIRO observations of comet 67P
• Evidence of Grain Alignment by Magnetically Enhanced Radiative Torques from Multiwavelength Dust Polarization Modeling of HL Tau
• Improving Monte Carlo radiative transfer simulations: A shift of framework
• Time-dependent Monte Carlo continuum radiative transfer
• Limitations of the modified blackbody fit method for determining molecular cloud properties
• Wavelength-dependent far-infrared polarization of HL Tau observed with SOFIA/HAWC+