Radiative transfer in spherical circumstellar dust envelopes. IV. The infrared emissivity profile and composition of the dust in NGC 7027

Journal Article · Thu Jan 01 04:00:00 EST 1976 · Astrophys. J., v. 203, no. 1, pp. 177-181

DOI:https://doi.org/10.1086/154061· OSTI ID:4028933

Apruzese, J P

Using radiative transfer methods described in the previous papers of this series, dust-emission models of the bright planetary nebula NGC 7027 have been calculated. An analysis of the infrared continuum of NGC 7027 based upon these calculations shows the following: If the spatial dust distribution coincides with the ionized gas distribution as given by Scott in 1973 (within approx.3.2'' from the center), the infrared continuum may be produced by an unknown substance whose infrared emissivity declines with increasing wavelength to about 50 $mu$ and then rises. If there exists a cool outer dust shell beyond 5''-6'' from the central source, the observed infrared continuum may be produced by iron grains of radius 1 $mu$ or by a mixture of smaller iron and graphite grains. (AIP)

• Research Organization: Physics and Astronomy Department, University of Wyoming
• Sponsoring Organization: USDOE
• NSA Number: NSA-33-030792
• OSTI ID: 4028933
• Journal Information: Astrophys. J., v. 203, no. 1, pp. 177-181, Journal Name: Astrophys. J., v. 203, no. 1, pp. 177-181; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

*COSMIC GASES-- IONIZATION
*PLANETARY NEBULAE-- INFRARED RADIATION
640105* --Physics Research--Astrophysics & Cosmology-- Galaxies
EMISSIVITY
GRAPHITE
INTERSTELLAR GRAINS
IRON
N56200 --Physics (Astrophysics & Cosmology)--Stars
N56500* --Physics (Astrophysics & Cosmology)--Galaxies
RADIANT HEAT TRANSFER
SPATIAL DISTRIBUTION