we wish to measure the spectral indices of wolf-rayet winds in the wavelength range - the mid- to far infrared - believed to be determined in the accelerating region of the winds. these data will be combined with ground-based (sub)millimetre and radio data to form spectral energy distributions over four decades of wavelength for comparison with wind models. the spectral indices are determined by recombination in the winds, itself determined by the electron and ion densities, which are determined by the radial velocity and ionization profiles in the wind. we are particularly interested in the velocity profiles as these shed light on the still poorly understood wind driving mechanism. we also seek spectra of two of the lowest excitation nitrogen sequence stars, one of which (wr122) appears to have a spectral energy distribution from ground-based observations quite unlike any other. this star may be a transition object in a very short-lived phase of its evolution and will be directly compared with another star of a more common subtype and believed to be near the beginning of its wr phase.
Instrument
PHT03
Temporal Coverage
1996-09-19T23:34:23Z/1997-10-15T19:53:08Z
Version
1.0
Mission Description
The Infrared Space Observatory (ISO) was the world's first true orbiting infrared observatory. Equipped with four highly-sophisticated and versatile scientific instruments, it was launched by Ariane in November 1995 and provided astronomers world-wide with a facility of unprecedented sensitivity and capabilities for a detailed exploration of the Universe at infrared wavelengths.
