SIMBAD references

A new analysis of long-slit CGS4 United Kingdom Infrared Telescope spectra of the 3.3-µm feature of the Red Rectangle and its evolution with offset along the NW whisker of the nebula is presented. The results support a proposed two-component interpretation for the 3.3-µm feature with peak wavelengths near 3.28 and 3.30µm. Both components exhibit a small shift to shorter wavelength with increasing offset from the central star which, by comparison with laboratory studies, is consistent with a decrease in the temperature of the carriers with distance from HD 44179. The two-component approach is also applied to 3.3-µm data for the Red Rectangle, Orion Bar D2 and Orion Bar H2S1 from Infrared Space Observatory Short Wavelength Spectrometer (SWS) studies.