BICE
the Balloon-borne Infrared Carbon Explorer (BICE)
Mission Descriptions
Overview
BICE is a balloon-borne telescope aimed at measuring the far-infrared [CII] spectral line with high precision over a wide area. The [CII] line is generated in moderately ionized regions and is a crucial spectral line for understanding the physical and chemical processes in interstellar space and the global structure of the Milky Way.
Balloon flight experiments were conducted in the United States and Australia in 1991 and 1992. BICE was equipped with an ultra-low temperature Fabry-Pérot spectrometer and succeeded a Galactic plane survey observation of [CII] line emissions at 158 microns. Observational data were obtained from three flights, each lasting about 8-12 hours, at a floating altitude of approximately 36-39 km.
Observation Instruments
BICE uses a compact, high-resolution Fabry-Pérot spectrometer, and the detector is a stressed Ge:Ga photoconductor, which is highly sensitive to the [CII] line. The entire optical system is cooled to 2 K using superfluid liquid helium to minimize noise from background radiation of the observational equipment.
The telescope employs an "off-axis, oversized optics," reducing background radiation and achieving high detection sensitivity.
Achievements
BICE conducted mapping observations of the [CII] emission line over a wide area of the Galactic plane, and observed strong diffuse components. Observations were also made of Cygnus X, the rho Ophiuchi dark cloud, the Large Magellanic Cloud, and other interstellar clouds, revealing the morphology of the interstellar clouds.