The infrared spectrum of the Galactic center and the composition of interstellar dust.

We have obtained 5-8 micrometers spectra of the Galactic center from the Kuiper Airborne Observatory at resolving powers of approximately 50, approximately 150, and approximately 300. These spectra show absorption features at 5.5, 5.

Is H2O present on Io? The detection of a new strong band near 3590 cm-1 (2.79 micrometers).

A strong absorption band at 3590 +/- 20 cm-1 (2.790 +/- 0.015 micrometers) has been discovered in the spectrum of Io using the Kuiper Airborne Observatory (KAO).

The 2.5-5.0 micrometers spectra of Io: evidence for H2S and H2O frozen in SO2.

Infrared spectra of Io in the region 2.5-5.0 micrometers, including new observational data, are analyzed using detailed laboratory studies of plausible surface ices.

The discovery of a new infrared emission feature at 1905 wavenumbers (5.25 microns) in the spectrum of BD +30 degrees 3639 and its relation to the polycyclic aromatic hydrocarbon model.

We have discovered a new IR emission feature at 1905 cm-1 (5.25 microns) in the spectrum of BD +30 degrees 3639. This feature joins the family of well-known IR emission features at 3040, 2940, 1750, 1610, "1310," 1160, and 890 cm-1 (3.

The infrared emission bands. II. A spatial and spectral study of the Orion Bar.

We have studied the spectral and spatial distribution across the Orion Bar of the 3-14 micrometers emission, including hydrogen Brackett alpha and 12.8 micrometers [Ne II] emission lines and several "dust" emission features. The data indicate that the "dust" consists of three components; (1) "classical" dust with a temperature of approximately 60 K accounting for emission longward of 20 micrometers, (2) amorphous carbon particles or polycyclic aromatic hydrocarbon (PAH) clusters (approximately 400 C atoms) which produce broad emission features in the 6-9 and 11-13 micrometers bands, and (3) free PAHs which emit in sharper bands (most strongly at 3.

New emission features in the 11-13 micron region and their relationship to polycyclic aromatic hydrocarbons.

If the "11.3 microns" emission feature seen in the spectra of many planetary nebulae, H II regions, and reflection nebulae is due to polycyclic aromatic hydrocarbons (PAHs), then additional features should be present between 11.3 and 13.

The infrared emission bands. III. Southern IRAS sources.

We present airborne 5-8 micrometers spectra of southern IRAS sources which reveal strong polycyclic aromatic hydrocarbon (PAH) emission features. The good correlation between the bands, in particular the dominant 6.2 and "7.

Infrared emission from comets.

A brief discussion of the infrared observations from 4 to 20 micrometers of seven comets is presented. The observed infrared emission from comets depends primarily on their heliocentric distance. A model based on grain populations composed of a mixture of silicate and amorphous carbon particles in the mass ratio of about 40 to 1, with a power-law size distribution similar to that inferred for comet Halley, is applied to the observations.

Airborne and groundbased spectrophotometry of comet P/Halley from 5-13 micrometers.

Spectrophotometry from 5-10 micrometers (delta lambda/lambda approximately 0.02) of comet Halley was obtained from the Kuiper Airborne Observatory on 1985 December 12.1 and 1986 April 8.

Infrared Astronomy After IRAS.

The 250,000 sources in the recently issued Infrared Astronomy Satellite (IRAS) all-sky infrared catalog are a challenge to astronomy. Many of these sources will be studied with existing and planned ground-based and airborne telescopes, but many others can no longer even be detected now that IRAS has ceased to operate. As anticipated by advisory panels of the National Academy of Sciences for a decade, study of the IRAS sources will require the Space Infrared Telescope Facility (SIRTF), a cooled, pointed telescope in space.

Io: an intense brightening near 5 micrometers.

Spectrophotometric observations of the jovian satellite Io on 20 and 21 February 1978 (Universal Time) were made from 1.2 to 5.4 micrometers.

Effect of the Shuttle contaminant environment on a sensitive infrared telescope.

A sensitive ir telescope on the Space Shuttle Orbiter will be limited in its performance by fluctuations in the ir radiation from the natural environment and the contaminant atmosphere. Models of the Orbiter's contaminant atmosphere were used to predict its spectral radiance from 3 microm to 300 microm. At 350 km, statistical fluctuations in the radiation from a water vapor column density of 10(12) cm(-2) produce a noise equivalent power of about 2 x 10(-17) W/Hz(1/2) in a 1 min of arc field of view of a 1-m diameter telescope with a 10-microm spectral bandwidth.

Water vapor absorption spectra of the upper atmosphere (45-185 cm(-1)).

The far ir nighttime absorption spectrum of the earth's atmosphere above 14 km is determined from observations of the bright moon. The spectra were obtained using a Michelson interferometer attached to a 30-cm telescope aboard a high-altitude jet aircraft. Comparison with a single-layer model atmosphere implies a vertical column of 3.