The 6 $\mu$m Feature as A Tracer of Aliphatic Components of Interstellar Carbonaceous Grains

Abstract

An unidentified infrared emission (UIE) feature at 6.0 $\mu$m is detected in a number of astronomical sources showing the UIE bands. In contrast to the previous suggestion that this band is due to C=O vibrational modes, we suggest that the 6.0 $\mu$m feature arises from olefinic double-bond functional groups. These groups are likely to be attached to aromatic rings which are responsible for the major UIE bands. The possibility that the formation of these functional groups is related to the hydrogenation process is discussed.

arXiv comment43 pages, 15 figures, accepted for publication in the Astrophysical Journal

References in corpus (31)

• The Infrared Spectrograph on the Spitzer Space Telescope
• The rich 6 to 9 um spectrum of interstellar PAHs
• The SMART Data Analysis Package for the Infrared Spectrograph on the Spitzer Space Telescope
• The evolution of amorphous hydrocarbons in the ISM: dust modelling from a new vantage point
• The CH out-of-plane bending modes of PAH molecules in astrophysical environments
• The unusual hydrocarbon emission from the early carbon star HD 100764: The connection between aromatics and aliphatics
• A Mid-Infrared Imaging Survey of Proto-Planetary Nebula Candidates
• Are C60 molecules detectable in circumstellar shells of R Coronae Borealis stars?
• A mid-infrared imaging catalogue of post-AGB stars
• Unidentified Infrared Emission bands: PAHs or MAONs?
• Properties of the close binary and circumbinary torus of the Red Rectangle
• Ice features in the mid-IR spectra of galactic nuclei
• What are the Hot R Coronae Borealis Stars?
• The mixed chemistry phenomenon in Galactic Bulge PNe
• The 5.25 & 5.7 $\mu$m Astronomical Polycyclic Aromatic Hydrocarbon Emission Features
• The nature of dust in compact Galactic planetary nebulae from Spitzer spectra
• The characteristics of the IR emission features in the spectra of Herbig Ae stars: Evidence for chemical evolution
• A survey for water maser emission towards planetary nebulae. New detection in IRAS 17347-3139
• On the viability of the PAH model as an explanation of the unidentified infrared emission features
• [SiPAH]+ pi-Complexes in the Interstellar Medium
• The Dust Properties of Two Hot R Coronae Borealis Stars and a Wolf-Rayet Central Star of a Planetary Nebula: in Search of a Possible Link
• Polycyclic Aromatic Hydrocarbons Orbiting HD 233517, an Evolved Oxygen-Rich Red Giant
• A Theoretical Study on the Vibrational Spectra of PAH Molecules with Aliphatic Sidegroups
• On the origin of the 11.3 micron unidentified infrared emission feature
• Dust around R Coronae Borealis stars: I. Spitzer/IRS observations
• Identification of three new proto-Planetary Nebulae exhibiting the unidentified feature at 21 um
• Structure of the Mid-Infrared Emitting Disk Around WL16
• Complex Organic and Inorganic Compounds in Shells of Lithium-rich K Giant Stars
• On the carbonaceous carriers of IR plateau and continuum emission
• The eclipsing binary TY CrA revisited: What near-IR light curves tell us
• Evolution of PAH Features from Proto- to Planetary Nebulae

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