we propose to investigate the newly discovered 7.15 micron oxygen-rich (or) circumstellar emission feature by observing its profile and distribution among approximately 50 oxygen-rich stars distributed throughout the sky. we expect this study to place constraints on the abundances, stellar evolution and chemistry of dust formation in these stars, and the importance of the emitting material as a possible inter- stellar dust component. the iras autoclass ii study of cheeseman et al. 1989 provides a guide from which we select a set of stars representing the entire population of or stars. one star is selected from each of the 32 or subclasses expected to have the feature present. based upon the work of goebel et al.(1994 ap.j. july 15,1994), these objects have a high probability of displaying the 7.15 um feature. stars from each r^ant subclass need to be observed with the sws throughout their entire spectral range so that all spectral features may be accurately profiled, defined, and correlated with the 7.15 um feature. high reso- lution scans are required to determine the influence of molecular bands on the features at 7.15, 10, 11.3, 13.1, 18, and 19.7 um. shape and relative strength of the features should enable identification of the responsible dust component. once high resolution scans of a rep- resentative sample of or stars have been obtained, the low resolution spectra of survey investigators can be used to supplement our statis- tics, but not to determine the confusing influences of molecular bands, nor meet the goals of this proposal. we anticipate reciprocal sharing of the proposed aot sws01-3 high resolution data with other groups that have aot sws01-1 low resolution data of or objects, notably price, tsuji, de jong, heske, waters, and barlow. the 7.15 um feature is in a spectral region blocked completely by the earth.s atmospheric water vapor. iso is the only platform with sufficient sensitivity, sky cove...rage, and instrumentation able to address the goals set forth.
Instrument
SWS01
Temporal Coverage
1996-04-09T09:14:57Z/1997-03-02T21:51:09Z
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.
