ARGO 1993 OBSERVATIONS OF INTERSTELLAR DUST EMISSION

We describe observations of Galactic dust emission at millimeter/submillimeter wavelengths (four bands at 2.0, 1.2, 0.8, and 0.5 mm), carried out by a balloon-borne telescope during the ARGO 1993 flight. We have observed the Galactic plane in Aquila and Galactic cirrus emission in Aries, Taurus, and Hercules. The signals detected in the bands of ARGO are well correlated with the Galactic dust emission mapped by IRAS at 100 mu m. The dust spectrum in Aquila is well described by a single-temperature distribution with T-d = 20.3 +/- 0.8 K and spectral index of emissivity alpha = 1.54 +/- 0.11. In Aries and Taurus we find again a single-temperature distribution, with T-d = 20.1 +/- 1.2 K and alpha = 1.50 +/- 0.17. The dust emission in Hercules has been detected only in the high-frequency channel, and upper limits to the millimeter-wave emission are derived: we conclude that dust cannot mimic the cosmic microwave background anisotropy detected in the same region. The possible presence of a colder dust component is also discussed.