Photodissociation of small carbonaceous molecules of astrophysical interest

@article{Hemert2008PhotodissociationOS,
  title={Photodissociation of small carbonaceous molecules of astrophysical interest},
  author={M. Hemert and E. Dishoeck},
  journal={Chemical Physics},
  year={2008},
  volume={343},
  pages={292-302}
}
Astronomical observations have shown that small carbonaceous molecules can persist in interstellar clouds exposed to intense ultraviolet radiation. Current astrochemical models lack quantitative information on photodissociation rates in order to interpret these data. We here present ab initio multi-reference configurationinteraction calculations of the vertical excitation energies, transition dipole moments and oscillator strengths for a number of astrophysically relevant molecules: C3, C4, C2H… Expand

Tables from this paper

Photodissociation and photoionisation of atoms and molecules of astrophysical interest
A new collection of photodissociation and photoionisation cross sections for 102 atoms and molecules of astrochemical interest has been assembled, along with a brief review of the basic processesExpand
Interstellar Anions: The Role of Quantum Chemistry.
  • R. Fortenberry
  • Physics, Medicine
  • The journal of physical chemistry. A
  • 2015
TLDR
The role that valence and dipole-bound excited states may play in the formation, detection, and lifetime of anions that may yet be observed in the ISM and how quantum chemistry enhances this understanding is reviewed. Expand
Statistical universal branching ratios for cosmic ray dissociation, photodissociation, and dissociative recombination of the C(n=2-10), C(n=2-4)H and C3H2 neutral and cationic species
Context. Fragmentation-branching ratios of electronically excited molecular species are of first importance for the modeling of gas phase interstellar chemistry. Despite experimental and theoreticalExpand
Carbon fractionation in photo-dissociation regions
We upgraded the chemical network from the UMIST Database for Astrochemistry 2006 to include isotopes such as ^{13}C and ^{18}O. This includes all corresponding isotopologues, their chemical reactionsExpand
Negative Ion Chemistry in the Coma of Comet 1P/Halley
Negative ions (anions) were identified in the coma of comet 1P/Halley during in situ Electron Electrostatic Analyzer measurements performed by the Giotto spacecraft in 1986. These anions wereExpand
Photodissociation dynamics of propargylene, HCCCH.
TLDR
A joint theoretical and experimental study on the photodissociation of the C3H2 isomer propargylene, HCCCH, combining velocity map imaging with nonadiabatic trajectory surface hopping calculations suggest a predissociation in the T4-T6 state and lead to a translational energy distribution and photofragment angular distribution that match the experimentally observed ones very well. Expand
Laboratory Astrochemistry: Gas-Phase Processes
A major aim of astrochemistry is to explain the nature and abundance of the molecules observed in the interstellar medium (ISM). Three kinds of activity are involved: (a) the spectroscopicExpand
Coulomb explosion of polycyclic aromatic hydrocarbons induced by heavy cosmic rays: carbon chains production rates
Cosmic Rays (CR) process the matter of the Interstellar Medium. Such energetic processing not only modifies the interstellar matter but also injects chemical species in the gas phase. In this work,Expand
Photochemistry of C3Hp hydrocarbons in Titan’s stratosphere revisited
The description of C3 hydrocarbon chemistry in current photochemical models of Titan's atmosphere is found to be far from complete. We have carefully investigated the photochemistry involving C3HpExpand
Photodissociation dynamics of cyclopropenylidene, c-C3 H2.
TLDR
The fragmentation channels accessed by the molecule following internal conversion are probed using velocity map imaging (VMI) so that the identity of the fragmentation products and their corresponding energy distributions can be definitively assigned. Expand
...
1
2
3
4
...

References

SHOWING 1-10 OF 197 REFERENCES
Photodissociation Processes in Diatomic Molecules of Astrophysical Interest
Publisher Summary This chapter describes the photodissociation processes in diatomic molecules of astrophysical interest. In contrast to direct photodissociation involving continuous absorption andExpand
Detection of C3 in Diffuse Interstellar Clouds
The smallest polyatomic carbon chain, C3, has been identified in interstellar clouds (Av ~ 1 mag) toward ζ Ophiuchi, 20 Aquilae, and ζ Persei by detection of the origin band in its A 1Πu-X 1ΣExpand
Laboratory and Astronomical Identification of the Negative Molecular Ion C6H
The negative molecular ion C6H- has been detected in the radio band in the laboratory and has been identified in the molecular envelope of IRC +10216 and in the dense molecular cloud TMC-1. TheExpand
Photodissociation of water in the à band revisited with new potential energy surfaces
Theoretical calculations on the photodissociation of water in the first absorption band have been used to test the accuracy of three available potential energy surfaces for the first excited state ofExpand
Limits to Interstellar C4 and C5 toward ζ Ophiuchi
We have made a sensitive search for the origin bands in the known electronic transitions of the linear carbon chains C4 and C5 at 3789 and 5109 A toward ζ Oph (Av ≤ 1). The incentive was a recentExpand
Photodissociation Dynamics
The field of photodissociation dynamics has grown explosively in the past few decades. Spearheaded by developments in laser and molecular beam techniques, studies of photodissociation dynamics nowExpand
LARGE MOLECULES IN CARBON VAPOR
The molecular orbital theory is used in appropriate semi-empirical forms to predict the properties of carbon vapor. The results indicate that linear polyatomic molecules: C = C = C - - - C = C: areExpand
Observations of Long CnH Molecules in the Dust Cloud TMC-1
We report detection of the J = 15.5-14.5 and 17.5-16.5 transitions of C8H, a sensitive upper limit for the J=10.5-9.5 transition of C7H, and measurements of two low-frequency transitions of C6H inExpand
Photoprocesses in protoplanetary disks.
TLDR
The parameters which make disks different from more traditional PDRs are discussed, including the shape of the UV radiation field, grain growth, the absence of PAHs, the gas/dust ratio and the presence of inner holes. Expand
Photodissociation of linear carbon clusters Cn (n=4-6)
The photodissociation of mass-selected linear carbon clusters (Cn, n = 4−6) is studied using fast beam photofragment translational spectroscopy. The photofragment yield (PFY) spectra consist ofExpand
...
1
2
3
4
5
...