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Title: Scattering Properties of Large Irregular Cosmic Dust Particles at Visible Wavelengths

Abstract

The effect of internal inhomogeneities and surface roughness on the scattering behavior of large cosmic dust particles is studied by comparing model simulations with laboratory measurements. The present work shows the results of an attempt to model a dust sample measured in the laboratory with simulations performed by a ray-optics model code. We consider this dust sample as a good analogue for interplanetary and interstellar dust as it shares its refractive index with known materials in these media. Several sensitivity tests have been performed for both structural cases (internal inclusions and surface roughness). Three different samples have been selected to mimic inclusion/coating inhomogeneities: two measured scattering matrices of hematite and white clay, and a simulated matrix for water ice. These three matrices are selected to cover a wide range of imaginary refractive indices. The selection of these materials also seeks to study astrophysical environments of interest such as Mars, where hematite and clays have been detected, and comets. Based on the results of the sensitivity tests shown in this work, we perform calculations for a size distribution of a silicate-type host particle model with inclusions and surface roughness to reproduce the experimental measurements of a dust sample. The model fitsmore » the measurements quite well, proving that surface roughness and internal structure play a role in the scattering pattern of irregular cosmic dust particles.« less

Authors:
; ; ;  [1]; ;  [2]
  1. Instituto de Astrofìsica de Andalucìa, CSIC, Glorieta de la Astronomìa s/n, E-18008 Granada (Spain)
  2. Department of Physics, P.O. Box 64, FI-00014 University of Helsinki (Finland)
Publication Date:
OSTI Identifier:
22661226
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 838; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASTROPHYSICS; CLAYS; COMETS; COMPARATIVE EVALUATIONS; COSMIC DUST; DISTRIBUTION; HEMATITE; ICE; MARS PLANET; PARTICLE MODELS; POLARIZATION; REFRACTIVE INDEX; ROUGHNESS; SATELLITE ATMOSPHERES; SATELLITES; SCATTERING; SENSITIVITY; SIMULATION; WATER; WAVELENGTHS

Citation Formats

Escobar-Cerezo, J., Palmer, C., Muñoz, O., Moreno, F., Penttilä, A., and Muinonen, K. Scattering Properties of Large Irregular Cosmic Dust Particles at Visible Wavelengths. United States: N. p., 2017. Web. doi:10.3847/1538-4357/AA6303.
Escobar-Cerezo, J., Palmer, C., Muñoz, O., Moreno, F., Penttilä, A., & Muinonen, K. Scattering Properties of Large Irregular Cosmic Dust Particles at Visible Wavelengths. United States. doi:10.3847/1538-4357/AA6303.
Escobar-Cerezo, J., Palmer, C., Muñoz, O., Moreno, F., Penttilä, A., and Muinonen, K. Mon . "Scattering Properties of Large Irregular Cosmic Dust Particles at Visible Wavelengths". United States. doi:10.3847/1538-4357/AA6303.
@article{osti_22661226,
title = {Scattering Properties of Large Irregular Cosmic Dust Particles at Visible Wavelengths},
author = {Escobar-Cerezo, J. and Palmer, C. and Muñoz, O. and Moreno, F. and Penttilä, A. and Muinonen, K.},
abstractNote = {The effect of internal inhomogeneities and surface roughness on the scattering behavior of large cosmic dust particles is studied by comparing model simulations with laboratory measurements. The present work shows the results of an attempt to model a dust sample measured in the laboratory with simulations performed by a ray-optics model code. We consider this dust sample as a good analogue for interplanetary and interstellar dust as it shares its refractive index with known materials in these media. Several sensitivity tests have been performed for both structural cases (internal inclusions and surface roughness). Three different samples have been selected to mimic inclusion/coating inhomogeneities: two measured scattering matrices of hematite and white clay, and a simulated matrix for water ice. These three matrices are selected to cover a wide range of imaginary refractive indices. The selection of these materials also seeks to study astrophysical environments of interest such as Mars, where hematite and clays have been detected, and comets. Based on the results of the sensitivity tests shown in this work, we perform calculations for a size distribution of a silicate-type host particle model with inclusions and surface roughness to reproduce the experimental measurements of a dust sample. The model fits the measurements quite well, proving that surface roughness and internal structure play a role in the scattering pattern of irregular cosmic dust particles.},
doi = {10.3847/1538-4357/AA6303},
journal = {Astrophysical Journal},
number = 1,
volume = 838,
place = {United States},
year = {Mon Mar 20 00:00:00 EDT 2017},
month = {Mon Mar 20 00:00:00 EDT 2017}
}
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