we wish to determine the neon/helium abundance ratio in wolf-rayet winds by measuring in sws aot band-3a (12.0 - 16.5 micron) with aot sws06 the flux of the [neii] 12.184 micron and [neiii] 15.55 micron and the neighbouring heii emission lines in wr stars with galactocentric distances ranging from 6 kpc to 10 kpc from the sun. we wish simulataneous spectrophotometric observations in sws aot band-1a (2.38 - 2.60) where emission lines of civ, heii and he i occur. the width of those spectral lines will be a measure of the wr steller wind velocities, since the [neiii] lines are formed where the winds have reached their terminal velocities. the abundance and velocities together will allow the determination of mass loss rates. the neon abundance determinations are a crucial check of stellar evolution models for massive stars, which predict a much larger than solar neon abundance.
Instrument
SWS06
Temporal Coverage
1996-09-01T04:33:46Z/1997-03-07T22:53:51Z
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.
