Encyclopedia of Astrobiology

Living Edition
| Editors: Muriel Gargaud, William M. Irvine, Ricardo Amils, Henderson James Cleaves, Daniele Pinti, José Cernicharo Quintanilla, Michel Viso

Unidentified Infrared Emission Bands

  • Sun Kwok
Living reference work entry
DOI: https://doi.org/10.1007/978-3-642-27833-4_5077-4


The term unidentified infrared emission (UIE) bands refers to a family of emission features observed in a variety of astronomical sources, including the aromatic features at 3.3, 6.2, 7.7, 8.6, and 11.3 μm; aliphatic features at 3.4 and 6.9 μm; and broad emission plateaus at 8, 12, and 17 μm, as well as a host of weaker features that are too broad to be atomic or molecular lines.


A family of strong infrared emission bands at 3.3, 6.2, 7.7, 8.6, 11.3, and 12.7 μm were first detected in the young carbon-rich planetary nebula NGC 7027 (Gillett et al. 1973; Russell et al. 1977) (Fig. 1) and in the reflection nebula HD 44179 (Russell et al. 1978). Since the initial discovery, these features are now widely observed in HII regions, reflection nebulae, planetary nebulae, protoplanetary nebulae, and the diffuse interstellar medium of our own and other galaxies.


Polycyclic Aromatic Hydrocarbon Emission Feature Central Star Planetary Nebula Young Stellar Object 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
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References and Further Reading

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Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  1. 1.Faculty of ScienceThe University of Hong KongHong KongChina