Spheroidal core-mantle particle absorption, scattering, and polarisation in the long-wavelength limit

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Jones, Ant, Ysard, Nathalie
Natura: Preprint
Pubblicazione: 2026
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866912910305918976
author Jones, Ant
Ysard, Nathalie
author_facet Jones, Ant
Ysard, Nathalie
contents The numerical calculation of optical properties (extinction, absorption, scattering and polarisation efficiencies) is often time-consuming for non-spherical and inhomogeneous particles. Where possible analytical methods are therefore to be preferred. We provide an analytical tool to derive the optical properties of mantled spheroidal particles, of arbitrary axis ratio, in the long wavelength limit (a << lambda), where the mantle form may be confocal, co-axial or of constant depth with respect to the particle core. We have developed an analytical approach to spheroidal core/mantle particle optical property calculations. The analytical method compares well with DDSCAT numerical calculations and, under limited circumstances, with those made using the Bruggemann effective medium theory (EMT).The analytical method presented here provides a useful tool to explore the optical and polarisation properties of core/mantle spheroidal particles at long wavelengths (lambda >~ 8mu) and is simpler and faster to implement than corresponding numerical methods. We caution against the use of EMT methods in approximating the optical properties of core/mantle particles.
format Preprint
id arxiv_https___arxiv_org_abs_2601_01515
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Spheroidal core-mantle particle absorption, scattering, and polarisation in the long-wavelength limit
Jones, Ant
Ysard, Nathalie
Astrophysics of Galaxies
Optics
The numerical calculation of optical properties (extinction, absorption, scattering and polarisation efficiencies) is often time-consuming for non-spherical and inhomogeneous particles. Where possible analytical methods are therefore to be preferred. We provide an analytical tool to derive the optical properties of mantled spheroidal particles, of arbitrary axis ratio, in the long wavelength limit (a << lambda), where the mantle form may be confocal, co-axial or of constant depth with respect to the particle core. We have developed an analytical approach to spheroidal core/mantle particle optical property calculations. The analytical method compares well with DDSCAT numerical calculations and, under limited circumstances, with those made using the Bruggemann effective medium theory (EMT).The analytical method presented here provides a useful tool to explore the optical and polarisation properties of core/mantle spheroidal particles at long wavelengths (lambda >~ 8mu) and is simpler and faster to implement than corresponding numerical methods. We caution against the use of EMT methods in approximating the optical properties of core/mantle particles.
title Spheroidal core-mantle particle absorption, scattering, and polarisation in the long-wavelength limit
topic Astrophysics of Galaxies
Optics
url https://arxiv.org/abs/2601.01515