8-13 micron spectroscopy of young stars

摘要

We present 8-13 μm spectra of 23 young stars acquired with the UKIRT CGS3 spectrometer, include- ing T Tauri, Herbig Ae/Be, and FU Orionis star. Silicate emission and absorption features can generally be matched with the Trapezium emissivity, by employing simple models to account for optical depth effects. Two Herbig Ae/Be objects, LkHα208 and LkHα198, have emission features that peak at 9.3μm. These spectra can be adequately fitted with the Trapezium emissivity and a variable optical depth model, plus a hydrocarbon component. A different emissivity peaking at shorter wavelength is not ruled out; however, it is not a necessary conclusion from the observed spectra.