IRAS surface brightness maps of reflection nebulae in the Pleiades

Journal Article · Sun Feb 01 04:00:00 EST 1987 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/165024· OSTI ID:6466739

Castelaz, M W; Werner, M W; Sellgren, K

Surface brightness maps at 12, 25, 60, and 100 microns were made of a 2.5 deg x 2.5 deg area of the reflection nebulae in the Pleiades by coadding IRAS scans of this region. Emission is seen surrounding 17 Tau, 20 Tau, 23 Tau, and 25 Tau in all four bands, coextensive with the visible reflection nebulosity, and extending as far as 30 arcminutes from the illuminating stars. The infrared energy distributions of the nebulae peak in the 100 micron band, but up to 40 percent of the total infrared power lies in the 12 and 25 micron bands. The brightness of the 12 and 25 micron emission and the absence of temperature gradients at these wavelengths are inconsistent with the predictions of equilibrium thermal emission models. The emission at these wavelengths appears to be the result of micron nonequilibrium emission from very small grains, or from molecules consisting of 10-100 carbon atoms, which have been excited by ultraviolet radiation from the illuminating stars. 34 references.

• Research Organization: NASA, Ames Research Center, Moffett Field, CA; Hawaii Univ., Honolulu
• OSTI ID: 6466739
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 313; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COSMIC DUST
COSMIC GASES
DUSTS
ELECTROMAGNETIC RADIATION
EMISSION SPECTRA
ENERGY SPECTRA
FLUIDS
GASES
INFRARED RADIATION
MAPS
NEBULAE
RADIATIONS
SPECTRA
STAR CLUSTERS