What question did this study set out to answer?

The research aims to measure and characterize the polarized light and dust properties in the disk of HD 100453.

February 5, 20260 citations

Multiwavelength analysis of polarized light in HD 100453

Key Points

The research aims to measure and characterize the polarized light and dust properties in the disk of HD 100453.
Conducted high-contrast imaging from 0.55 to 2.2 μm using VLT/SPHERE instruments.
Corrected data for smearing effects to derive intrinsic polarized flux.
Used reference differential imaging to extract disk intensity in V and Ks bands.
Employed RADMC-3D radiative transfer modeling with a Henyey–Greenstein phase function.
Observed an increase in polarized flux from 0.3% to 1.2% across V and K bands.
Total intensity increased from 1.5% at V to 4.8% at K band.
Found that polarization fraction increased moderately from 40% to 55%.
Identified that the outer disk contains sub-micron-sized low porosity grains.
Noted higher linear polarization in spiral regions, indicating varied dust properties.

Abstract

Context. HD 100453 disk is a prototypical companion-disk interaction system hosting a pair of spirals and a substellar companion. Aims. We present new noncoronagraphic high-contrast imaging observations of HD 100453 with V filter on SPHERE/ZIMPOL. We aim to accurately measure the reflected polarized intensity, the disk intensity, and the degree of polarization at multiwavelength; characterize the dust properties in the disk ring and the companion-driven spiral arms; and search for the radial dependencies of dust scattering properties within the disk. Methods. We combined high-contrast imaging data of the reflected light from 0. 55 to 2. 2 μm using the V, I′, J, and Ks band data of ZIMPOL and IRDIS at VLT/SPHERE. For each observational epoch, we corrected for the smearing effect to derive the intrinsic disk-integrated polarized flux. We applied reference differential imaging to extract the disk intensity for the V and Ks bands using star hopping observations. We then used RADMC-3D radiative transfer modeling with a parametrized Henyey–Greenstein phase function to constrain the dust properties. Results. For the integrated intrinsic polarized flux of the disk, we derived a steady increase with wavelengths from Q_ /I_ (V) = 0. 3\% to Q_ /I_ (K) = 1. 2\%. We obtained the first V-band total intensity for HD 100453 with ZIMPOL star hopping. The integrated total flux Idisk/I★ (V) = 1. 5% increases to Idisk/I★ (K) = 4. 8%. Both the total intensity and the polarization fraction show red colors, and the intrinsic maximum degree of polarization increases moderately from 40% to 55%. From the V to Ks band, the dominating dust in the outer disk has an increasing scattering albedo and degree of polarization, while the asymmetry parameter slightly decreases. The outer disk of HD 100453 contains sub-micron-sized low porosity grains/aggregates. The cavity in scattered light is not empty and is replenished with optically thin dust with a maximum size of ≤ 0. 1 μm. The linear polarization is higher in the spiral region than in the other regions, suggesting different dust properties in those regions.

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