ABSORPTIONS IN THE VISIBLE OF PROTONATED PYRENE COLLISIONALLY COOLED TO 15 K

Journal Article · Sun Dec 01 00:00:00 EST 2013 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/778/2/L30· OSTI ID:22364121

Hardy, F. -X.; Gause, O.; Rice, C. A.

Protonated polycyclic hydrocarbons have been added to the list of suggested carriers of diffuse interstellar absorptions. To test this proposition requires laboratory spectra measured under interstellar conditions, in particular with the rotational and vibrational degrees of freedom equilibrated to low temperatures. This has been achieved for protonated pyrene with absorption bands in the visible, using an ion trap and collisional cooling to ≈15 K. A two-photon excitation-dissociation scheme was employed to record the (1) {sup 1} A' ← X {sup 1} A' electronic spectrum on around 10{sup 5} ions per duty cycle. The origin band of the absorption spectrum of this relatively large polycyclic aromatic species with 27 atoms is located at 4858.86 Å. Two further comparably intense spectral features are present at 4834.48 and 4809.32 Å. This is one of the largest protonated aromatics studied in the gas phase and compared to astronomical observations; however, it is not a carrier of known diffuse interstellar bands.

• OSTI ID: 22364121
• Journal Information: Astrophysical Journal Letters, Vol. 778, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ABSORPTION SPECTRA
ASTRONOMY
ASTROPHYSICS
ATOMS
COMPARATIVE EVALUATIONS
COOLING
DEGREES OF FREEDOM
DISSOCIATION
EXCITATION
INTERSTELLAR GRAINS
INTERSTELLAR SPACE
IONS
MOLECULES
PHOTONS
POLYCYCLIC AROMATIC HYDROCARBONS
PYRENE
TRAPS