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Recent Advances in Laboratory Infrared Spectroscopy of Polycyclic Aromatic Hydrocarbons: PAHs in the Far InfraredOver 25 years of observations and laboratory work have shown that the mid-IR spectra of a majority of astronomical sources are dominated by emission features near 3.3, 6.2, 7.7, and 11.2 microns, which originate in free polycyclic aromatic hydrocarbon (PAH) molecules. PAHs dominate the mid-IR emission from many galactic and extragalactic objects. As such, this material tracks a wide variety of astronomical processes, making this spectrum a powerful probe of the cosmos Apart from bands in the mid-IR, PAHs have bands spanning the Far-IR (FIR) and emission from these FIR features should be present in astronomical sources showing the Mid-IR PAH bands. However, with one exception, the FIR spectral characteristics are known only for a few neutral small PAHs trapped in salt pellets or oils at room temperature, data which is not relevant to astrophysics. Furthermore, since most emitting PAHs responsible for the mid-IR astronomical features are ionized, the absence of any experimental or theoretical PAH ion FIR spectra will make it impossible to correctly interpret the FIR data from these objects. In view of the upcoming Herschel space telescope mission and SOFIA's FIR airborne instrumentation, which will pioneer the FIR region, it is now urgent to obtain PAH FIR spectra. This talk will present an overview recent advances in the laboratory spectroscopy of PAHs, Highlighting the FIR spectroscopy along with some quantum calculations.
Document ID
20100036360
Acquisition Source
Ames Research Center
Document Type
Presentation
Authors
Mattioda, Andrew L.
(NASA Ames Research Center Moffett Field, CA, United States)
Ricca, Alessandra
(SETI Inst. Mountain View, CA, United States)
Tucker, Jonathan
(Amherst Coll. MA, United States)
Boersma, Christiaan
(NASA Ames Research Center Moffett Field, CA, United States)
Bauschlicher, Charles, Jr.
(NASA Ames Research Center Moffett Field, CA, United States)
Allamandola, Louis J.
(NASA Ames Research Center Moffett Field, CA, United States)
Date Acquired
August 25, 2013
Publication Date
May 31, 2010
Subject Category
Astronomy
Report/Patent Number
ARC-E-DAA-TN1570
Meeting Information
Meeting: PAHs and the Universe: A Symposium to Celebrate the 25th Anniversary of the PAH Hypothesis
Location: Toulouse, France
Country: France
Start Date: May 31, 2010
End Date: June 4, 2010
Sponsors: European Space Agency
Funding Number(s)
CONTRACT_GRANT: NNH06CC03B
Distribution Limits
Public
Copyright
Public Use Permitted.
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