Hostname: page-component-7c8c6479df-24hb2 Total loading time: 0 Render date: 2024-03-28T19:37:34.977Z Has data issue: false hasContentIssue false

Spitzer spectroscopy of unusual hydrocarbons in cool radiative environments

Published online by Cambridge University Press:  01 February 2008

G. C. Sloan*
Affiliation:
Cornell University, Space Sciences 108, Ithaca, NY 14853-6801 email: sloan@isc.astro.cornell.edu
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The Spitzer Space Telescope has discovered several objects with unusual spectra, where the emission features from polycyclic aromatic hydrocarbons (PAHs) are shifted to longer wavelengths than normally observed. Previously, only two of these class C PAH spectra had been identified. The new and larger sample reveals that PAHs emit at longer wavelengths when processed by cooler radiation fields. Limited laboratory data show that samples with mixtures of aromatic and aliphatic hydrocarbons produce emission features at longer wavelengths than purely aromatic samples. The aliphatic bonds are more fragile and would only survive in cooler radiation fields. In harsher radiation fields, the aliphatics attached to the aromatic hydrocarbons are destroyed.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2008

References

Allamandola, L. J., Hudgins, D. M., & Sandford, S. A. 1999, ApJ (Letter), 511, L115CrossRefGoogle Scholar
Allamandola, L. J., Tielens, A. G. G. M., & Barker, J. R. 1985, ApJ (Letter), 290, L25CrossRefGoogle Scholar
Duley, W. W. & Williams, D. A. 1979, Nature, 277, 40CrossRefGoogle Scholar
Furlan, E., et al. 2006, ApJS, 165, 568CrossRefGoogle Scholar
Geballe, T. R., Joblin, C., D'Hendecourt, L. B., Jourdain de Muizon, M., Tielens, A. G. G. M., & Leger, A. 1994, ApJ (Letter), 434, L15Google Scholar
Geballe, T. R., Tielens, A. G. G. M., Allamandola, L. J., Moorhouse, A., & Brand, P. W. J. L. 1989, ApJ, 341, 278CrossRefGoogle Scholar
Geballe, T. R., Tielens, A. G. G. M., Kwok, S., & Hrivnak, B. J. 1992, ApJ (Letter), 387, L89Google Scholar
Geballe, T. R., & van der Veen, W. E. C. J. 1990, A&A, 235, 9Google Scholar
Hony, S., Van Kerckhoven, C., Peeters, E., Tielens, A. G. G. M., Hudgins, D. M., Allamandola, L. J. 2001 A&A, 370, 1030Google Scholar
Houck, J. R., et al. 2004, ApJS, 154, 18CrossRefGoogle Scholar
Jones, A. P., Duley, W. W., Williams, D. A. 1990, QJRAS, 31, 567Google Scholar
Jura, M., et al. 2006, ApJ (Letter), 637, L45CrossRefGoogle Scholar
Keller, L. D., et al. 2008 ApJ, in pressGoogle Scholar
Kraemer, K. E., Sloan, G. C., Bernard-Salas, J., Price, S. D., Egan, M. P., & Wood, P. R. 2006, ApJ (Letter), 652, L25CrossRefGoogle Scholar
Kwok, S. 2004, Nature, 430, 985Google Scholar
Leger, A. & Puget, J. L. 1984, A&A (Letter), 137, L5Google Scholar
Li, A. & Draine, B. T. 2002, ApJ, 572, 232Google Scholar
Papoular, R., Conrad, J., Giuliano, M., Kister, J., & Mille, G. 1989, A&A, 217, 204Google Scholar
Peeters, E., Hony, S., Van Kerckhoven, C., Tielens, A. G. G. M., Allamandola, L. J., Hudgins, D. M., & Bauschlicher, C. W. 2002, A&A, 390, 1089Google Scholar
Pendleton, Y. J. & Allamandola, L. J. 2002, ApJS, 138, 75CrossRefGoogle Scholar
Sakata, A., Wada, S., Tanabe, T., & Onaka, T. 1984, ApJ (Letter), 287, L51CrossRefGoogle Scholar
Sloan, G. C., Bregman, J. D., Geballe, T. R., Allamandola, L. J., & Woodward, C. E. 1997, ApJ, 474, 735Google Scholar
Sloan, G. C., et al. 2005, ApJ, 632, 956Google Scholar
Sloan, G. C., et al. 2007, ApJ, 664, 1144CrossRefGoogle Scholar
Werner, M. W., et al. 2004, ApJS, 154, 1CrossRefGoogle Scholar