Interstellar circular polarization and the dielectric nature of dust grains

Journal Article · Sat Dec 01 04:00:00 EST 1990 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/169474· OSTI ID:6159409

Chlewicki, G; Greenberg, J M ^[1]

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1. SRON, Laboratorium voor Ruimteonderzoek, Groningen (Netherlands) Leiden Rijksuniversiteit (Netherlands)

The relationship between interstellar linear and circular polarization is reexamined. The derivation of optical constants for relevant materials is described, emphasizing general constraints on the electromagnetic response of an optical medium (Kramers-Kronig relations) which also provide the basis for the subsequent analysis of interstellar polarization. The formulas that relate the observed polarization to the properties of individual grains are summarized. It is shown that the apparent upper limit on the visual absorptivity of grains derived from earlier Mie theory calculations results from a violation of the Kramers-Kronig relations in the assumed optical constants of the particles. The analysis of circular and linear polarization in the interstellar medium is presented, and the implications of this analysis for grain models are addressed. 49 refs.

• OSTI ID: 6159409
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 365; ISSN ASJOA; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABSORPTIVITY
COSMIC DUST
COSMIC GASES
DIELECTRIC PROPERTIES
DUSTS
ELECTRICAL PROPERTIES
FLUIDS
GASES
INTERSTELLAR GRAINS
INTERSTELLAR SPACE
LIMITING VALUES
MATHEMATICAL MODELS
OPTICAL PROPERTIES
PARTICLES
PHYSICAL PROPERTIES
POLARIZATION
SCATTERING
SPACE