Dust emission of galactic cirrus from DIRBE observations
J. P. Bernard, F. Boulanger, F. X. Desert, M. Giard, G. Helou, J. L. Puget;
AaA, 1994, 291, L5
ABSTRACT:We present the spectral distribution of dust in the diffuse Interstellar
(ISM) as derived from the first release of the DIRBE (Diffuse Infrared
Background Explorer) data, in the wavelength range from 3.5 to 240
micrometers.
Although the spectrum of diffuse regions strongly decreases from 12
micrometers toward shorter wavelengths, it is found that some dust emission is
still present in the L and M bands.
On average, it corresponds to
approximately = 1% of the total IR emission.
The comparison with the 3.3 micrometer
Polycyclic Aromatic Hydrocarbon (PAH) feature emissivity of the diffuse medium
in the inner galaxy shows that only a small fraction (8-16%) of the DIRBE L
and ISM emission is likely to be produced by the 3.3 micrometer
feature.
Along with the presence of an important dust emission in the DIRBE M band,
where no PAH feature is expected, this implies that a continuum component
and/or other features from dust also contribute significantly to the short
wavelength emission.
The carrier of this emission still has to be
identified.
Large color variations are observed from region to region over most of the
DIRBE range, which might reflect abundance variations of the various dust
components.
KEYWORDS: cosmic dust, infrared astronomy, infrared radiation, infrared spectra, interstellar extinction, interstellar matter, abundance, emissivity, polycyclic aromatic hydrocarbons, temperature distribution
PERSOKEY:dust, DIRBE, fir, pah, MILKY WAY, mir, ,
CODE: bernard94