Polarization of far-infrared radiation from molecular clouds

Journal Article · Sun Oct 01 04:00:00 EDT 1989 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/167951· OSTI ID:5095860

Novak, G; Gonatas, D P; Hildebrand, R H; Platt, S R; Dragovan, M ^[1]

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1. Chicago Univ., IL (USA) AT T Bell Laboratories, Murray Hill, NJ (USA)

The paper reports measurements of the polarization of far-infrared emission from dust in nine molecular clouds. Detections were obtained in Mon R2, in the Kleinmann-Low (KL) nebula in Orion, and in Sgr A. Upper limits were set for six other clouds. A comparison of the 100 micron polarization of KL with that previously measured at 270 microns provides new evidence that the polarization is due to emission from magnetically aligned dust grains. Comparing the results for Orion with measurements at optical wavelengths, it is inferred that the magnetic field direction in the outer parts of the Orion cloud is the same as that in the dense core. This direction is nearly perpendicular to the ridge of molecular emission and is parallel to both the molecular outflow in KL and the axis of rotation of the cloud core. In Mon R2, the field direction which the measurements imply does not agree withthat derived from 0.9-2.2 micron polarimetry. The discrepancy is attributed to scattering in the near-infrared. In Orion and Sgr A, where comparisons are possible, the measurements are in good agreement with 10 micron polarization measurements. 55 refs.

• OSTI ID: 5095860
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 345; 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
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CHALCOGENIDES
COSMIC DUST
COSMIC GASES
DUSTS
ELECTROMAGNETIC RADIATION
FAR INFRARED RADIATION
FLUIDS
GASES
INFRARED RADIATION
INTERSTELLAR MAGNETIC FIELDS
INTERSTELLAR SPACE
LIMITING VALUES
MAGNETIC FIELDS
MAPS
NEBULAE
OXIDES
OXYGEN COMPOUNDS
POLARIMETRY
POLARIZATION
RADIATIONS
SPACE