Retrieving Dust Grain Sizes from Photopolarimetry: An Experimental Approach

Abstract

We present the experimental phase function, degree of linear polarization (DLP), and linear depolarization (deltaL) curves of a set of forsterite samples representative of low-absorbing cosmic dust particles. The samples are prepared using state-of-the-art size-segregating techniques to obtain narrow size distributions spanning a broad range of the scattering size parameter domain. We conclude that the behavior of the phase function at the side- and back-scattering regions provides information on the size regime, the position and magnitude of the maximum of the DLP curve are strongly dependent on particle size, the negative polarization branch is mainly produced by particles with size parameters in the approx. 6 to 20 range, and the deltaL is strongly dependent on particle size at all measured phase angles except for the exact backward direction. From a direct comparison of the experimental data with computations for spherical particles, it becomes clear that the use of the spherical model for simulating the phase function and DLP curves of irregular dust produces dramatic errors in the retrieved composition and size of the scattering particles: The experimental phase functions are reproduced by assuming unrealistically high values of the imaginary part of the refractive index. The spherical model does not reproduce the bell-shaped DLP curve of dust particles with sizes in the resonance and/or geometric optics size domain. Thus, the use of the Mie model for analyzing polarimetric observations might prevent locating dust particles with sizes of the order of or larger than the wavelength of the incident light.

arXiv commentPublished in ApJS

References in corpus (26)

• The Disk Substructures at High Angular Resolution Project (DSHARP): V. Interpreting ALMA maps of protoplanetary disks in terms of a dust model
• Millimeter-wave polarization of protoplanetary disks due to dust scattering
• Polarimetry with the Gemini Planet Imager: Methods, Performance at First Light, and the Circumstellar Ring around HR 4796A
• The Signature of Primordial Grain Growth in the Polarized Light of the AU Mic Debris Disk
• The evidence of radio polarization induced by the radiative grain alignment and self-scattering of dust grains in a protoplanetary disk
• Near-infrared scattered light properties of the HR4796A dust ring: a measured scattering phase function from 13.6deg to 166.6deg
• Two different evolutionary types of comets proved by polarimetric and infrared properties of their dust
• Light scattering by fractal dust aggregates: I. Angular dependence of scattering
• Near-Infrared Imaging Polarimetry of HD142527
• Non-azimuthal linear polarization in protoplanetary disks
• Two Different Grain Size Distributions within the Protoplanetary Disk around HD 142527 Revealed by ALMA Polarization Observation
• Unveiling Dust Aggregate Structure in Protoplanetary Disks by Millimeter-wave Scattering Polarization
• Experimental phase function and degree of linear polarization of cometary dust analogs
• A ring-like concentration of mm-sized particles in Sz 91
• Investigating dust trapping in transition disks with millimeter-wave polarization
• An Exo-Kuiper Belt and An Extended Halo around HD 191089 in Scattered Light
• Interpretation of the phase functions measured by the OSIRIS instrument for Comet 67P/Churyumov-Gerasimenko
• The lunar phases of dust grains orbiting Fomalhaut
• Effect of dust grain porosity on the appearance of protoplanetary disks
• Are the spiral arms in the MWC 758 protoplanetary disc driven by a companion inside the cavity?
• Direct Imaging of the HD 35841 Debris Disk: A Polarized Dust Ring from Gemini Planet Imager and an Outer Halo from HST/STIS
• Multiband Polarimetric Imaging of HR 4796A with the Gemini Planet Imager
• Self-scattering of non-spherical dust grains
• Models of Rosetta/OSIRIS 67P dust coma phase function
• The Gemini Planet Imager view of the HD 32297 debris disk
• HD 117214 debris disk: scattered-light images and constraints on the presence of planets

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