EDP Sciences
Free access
Volume 402, Number 2, May I 2003
Page(s) L13 - L16
Section Letters
DOI http://dx.doi.org/10.1051/0004-6361:20030370

A&A 402, L13-L16 (2003)
DOI: 10.1051/0004-6361:20030370


Possible contribution of olefins and heteroatoms to the Unidentified Infrared Bands

R. Papoular

Service d'Astrophysique and Service de Chimie Moléculaire, CEA Saclay, 91191 Gif-sur-Yvette, France
(Received 26 November 2002 / Accepted 12 March 2003)

The current assignments of the 11.3- $\mu$m feature are dicussed. An unbiased survey of correlation charts suggests that the olefinic group R 2C = CH 2 is a good alternative candidate. For the 12.7- $\mu$m feature, the best fits are provided by nitrites, R-O-N = O, and amines, R-N = H 2. Sulfones, SO 2, exhibit strong features near 7.7 and 8.6  $\mu$m, which may contribute to the UIBs. These additional functional groups are likely to be attached to the main hydrocarbon dust skeleton previously hypothesized.

Key words: ISM: dust, lines and bands, molecules -- infrared -- astrochemistry

© ESO 2003