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Published on: March 30, 2017
Fast radiative cooling of anthracene observed in a compact electrostatic storage ring
1Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon, 69622 Villeurbanne cedex, France.
Physical Review Letters
|February 26, 2013
Summary
Fast radiative cooling of anthracene molecular ions was observed. This rapid cooling, driven by electron fluorescence, is much faster than expected and has implications for polycyclic aromatic hydrocarbons in space.
Area of Science:
- Physical Chemistry
- Astrophysics
- Molecular Spectroscopy
Background:
- Polycyclic Aromatic Hydrocarbons (PAHs) are abundant in interstellar space.
- Understanding their cooling mechanisms is crucial for modeling interstellar conditions.
- Anthracene is a representative PAH molecule.
Purpose of the Study:
- To investigate the radiative cooling rates of anthracene molecular ions.
- To determine the mechanism responsible for fast cooling.
- To assess the implications for PAH lifetimes in astrophysical environments.
Main Methods:
- Utilized a compact electrostatic storage ring.
- Probed internal energy distribution of stored (C14H10)+ molecular ensemble.
- Employed laser excitation to measure radiative decay rates.
Main Results:
- Observed fast radiative cooling of anthracene molecular ions.
- Measured mean radiative decay rates between 120 to 250 s(-1) for internal energies of 6.6–6.8 eV.
- Identified electron fluorescence as the dominant cooling mechanism, exceeding infrared emission rates by two orders of magnitude.
Conclusions:
- Fast radiative cooling via electron fluorescence is a significant process for anthracene ions.
- This mechanism influences the cooling and survival of PAHs in interstellar conditions.
- Findings impact models of PAH evolution and distribution in space.
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