Crystalline Silicates in Evolved Stars. I. Spitzer/IRS Spectroscopy of IRAS16456-3542, 18354-0638, and 23239+5754

B. W. Jiang, Ke Zhang, Aigen Li, C. M. Lisse

Published 2013-01-14Version 1

We report the Spitzer Infrared Spectrograph (IRS) observations of three evolved stars: IRAS 16456-3542, 18354-0638, and 23239+5754. The 9.9--37.2um Spitzer/IRS high resolution spectra of these three sources exhibit rich sets of enstatite-dominated crystalline silicate emission features. IRAS 16456-3542 is extremely rich in crystalline silicates, with >90% of its silicate mass in crystalline form, the highest to date ever reported for crystalline silicate sources.