Thermal emission spectra provide specific information for the composition of debris ejected during the Deep Impact experiment. Comparisons with previously studied dusty objects including Hale-Bopp and a dust disk around a forming star named HD100546 help us understand and interpret the spectrum of Tempel 1 after impact, which is very different from spectrum taken before impact.
Infrared spectra spanning 5- to 35-µm of Tempel 1 and related objects are shown. From bottom to top: (i) spectrum of the ambient coma, taken by Spitzer Space Telescopes Infrared Spectrometer (IRS) 23 hours before impact (I); (ii) spectrum of the impact debris from the Deep Impact collision taken at I + 0.75 hours after impact; (iii) Infrared Space Observatory (ISO) spectrum of Comet Hale-Bopp (Crovisier et al. 1997 Science, 275, 1904.; (iv) ISO spectrum of Young Stellar Object (YSO) HD100546 (Malfait et al. 1998, A&A, 332, L25-L28). Note the logarithmic scale.
Photo Credit: NASA/UM C. M. Lisse et al., Science 313, 635 (2006); published online 13 July 2006 (10.1126/science.1124694). Reprinted with permission from AAAS.
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