J/ApJ/729/94 IR spectroscopy of PAH in 6-15µm band (Ricca+, 2011)
The infrared spectroscopy of polycyclic aromatic hydrocarbons with five- and
seven-membered fused ring defects.
Ricca A., Bauschlicher C.W.JR, Allamandola L.J.
<Astrophys. J., 729, 94 (2011)>
=2011ApJ...729...94R 2011ApJ...729...94R
ADC_Keywords: Atomic physics ; Interstellar medium ; Models
Keywords: astrochemistry - infrared: ISM - ISM: lines and bands -
ISM: molecules - line: identification - methods: numerical -
molecular data
Abstract:
Polycyclic aromatic hydrocarbon (PAH) growth and destruction are
thought to proceed via the occasional incorporation of five- and
seven-membered fused ring defects in the hexagonal carbon skeleton.
Using density functional theory, this paper investigates the effect
such five- and seven-membered fused ring defects have on the infrared
spectra of ovalene (OV; C32H14), circumovalene (c-OV; C66H20),
and circumcircumovalene (cc-OV; C112H26). The defects make only
small changes to the overall infrared (IR) spectra, both in the mid-IR
and in the far-IR, of these species. In addition to small shifts in
the positions of the bands between the PAHs with and without defects,
the most common effect of the defects is to increase the number of
bands. Except for an anion with the Stone-Wales defect, all of the
species studied have the C-C stretching band at 6.3um or at longer
wavelengths, the position in Classes B and C astronomical PAH spectra.
In the case of the Stone-Wales anion, the band falls at 6.20um,
suggesting that further study of defects is probably worthwhile, as
some PAHs with defects might be important in those sources (Class A)
that show a C-C stretching band that falls near 6.2um.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 50 208 Summary of the 6-15 microns band position
maxima and integrated band intensities
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See also:
J/A+A/527/A109 : Dust and PAH emission SEDs of disk galaxies (Popescu+, 2011)
J/ApJ/705/885 : PAH in galaxies at z∼0.1 (O'Dowd+, 2009)
J/ApJ/662/1309 : Rotational spectra of small PAHs (Thorwirth+, 2007)
J/A+A/319/318 : PAH hypothesis (Pauzat+ 1997)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- MolID Molecule identification (1)
11- 16 F6.3 um lam+ [5.7/16]? Cation band position maximum
18- 23 F6.1 km/mol Int+ ? Cation integrated band intensity (1)
25- 30 F6.3 um lam0 [5.7/16]? Neutral band position maximum
32- 36 F5.1 km/mol Int0 ? Neutral integrated band intensity (1)
38- 43 F6.3 um lam- [5.7/16]? Anion band position maximum
45- 50 F6.1 km/mol Int- ? Anion integrated band intensity (1)
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Note (1): Only bands with an intensity of 10km/mol for any charge state
are listed.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 13-Sep-2012