SILICATES AND AROMATIC-HYDROCARBONS IN THE 10 MICRON SPECTRUM OF THE TAURUS DARK CLOUD SOURCE ELIAS-1

We have obtained 10.4-12 mum spectra at spectral resolution R almost-equal-to 190 of the Herbig Ae star Elias 1 in the Taurus dark cloud with the UKIRT CGS3 spectrometer, along with an 8-13 mum spectrum at R almost-equal-to 55. The 11.2 mum emission feature matches the wavelength, shape, and FWHM of the 11.22 mum aromatic hydrocarbon band, consistent with the presence of other aromatic features. A strong 11.06 mum feature is present, and there are two possible new emission features at 11.6 and 11.76 mum. The strong silicate emission feature is broader and peaks at a longer wavelength than can be reproduced with the Trapezium emissivity. Larger grains, with mean radius a approximately 1.5 mum, appear to be required, a possible indication of grain growth around a young star.