Polycyclic aromatic hydrocarbon processing by cosmic rays

  title={Polycyclic aromatic hydrocarbon processing by cosmic rays},
  author={Elisabetta R. Micelotta and A. P. Jones and A. Blaauw Sterrewacht Leiden and Leiden University and The Netherlands. and Institut d'Astrophysique Spatiale and Universite de Paris Sud and Cnrs and Orsay and France. and Cresst and Nasa Goddard Space Flight Center and Greenbelt and Usa and Universities Space Research Association and Columbia and NASAArmstrong Flight Research Center and Moffett Field},
  journal={Astronomy and Astrophysics},
Context. Cosmic rays are present in almost all phases of the ISM. Polycyclic aromatic hydrocarbons (PAHs) and cosmic rays represent an abundant and ubiquitous component of the interstellar medium. However, the interaction between them has never before been fully investigated. Aims. To study the effects of cosmic ray ion (H, He, CNO and Fe-Co-Ni) and electron bombardment of PAHs in galactic and extragalactic environments. Methods. We calculate the nuclear and electronic interactions for… Expand
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
Destruction and multiple ionization of PAHs by X-rays in circumnuclear regions of AGNs
The infrared signatures of polycyclic aromatic hydrocarbons (PAHs) are observed in a variety of astrophysical objects, including the circumnuclear medium of active galactic nuclei (AGNs). These areExpand
The cycling of carbon into and out of dust.
It is found that significant carbonaceous dust re-processing and/or mantle accretion can occur in the outer regions of molecular clouds and that this dust will have significantly different optical properties from the dust in the adjacent diffuse ISM. Expand
Restructuring and destruction of hydrocarbon dust in the interstellar medium
A model describing the main processes determining the evolution of hydrocarbon dust grains of arbitrary size under astrophysical conditions corresponding to regions of ionized hydrogen (HII regions)Expand
The role of OH in the chemical evolution of protoplanetary disks. II. Gas-rich environments
Context. We present a method for including gas extinction of cosmic-ray-generated UV photons in chemical models of the midplane of protoplanetary disks, focusing on its implications on ice formationExpand
Differential electron emission from polycyclic aromatic hydrocarbon molecules under fast ion impact
The theoretical calculation based on the first-order Born approximation with correct boundary conditions (CB1), in general, reproduced the experimental observations qualitatively, for both the molecules, except in the low energy region for coronene, which indicates the role of collective excitation. Expand
The Stability of Cosmic Fullerenes and Fullerenic Aggregates
Abstract Establishing the stability of cosmic fullerenes and fullerenic aggregates is extremely relevant for a variety of reasons. For instance, the emission features of C60 and C70 fall in the sameExpand
Survival Depth of Organics in Ices under Low-energy Electron Radiation (?2?keV)
Icy surfaces in our solar system are continually modified and sputtered with electrons, ions, and photons from solar wind, cosmic rays, and local magnetospheres in the cases of Jovian and SaturnianExpand
Electron angular distributions and attachment rates in o-Benzyne and Phenyl aromatic molecules: the effect of the permanent dipoles
Free, gas-phase polycyclic aromatic hydrocarbons (PAHs) and related species are currently considered to play an important role in the interstellar/circumstellar medium as they are thought toExpand
Dissociation of polycyclic aromatic hydrocarbons: molecular dynamics studies
Dynamical studies of the dissociation of polycyclic aromatic hydrocarbon (PAH) radical cations in their ground electronic states with significant internal energy show that decreasing the internal energy or increasing the PAH size will favour the hydrogen loss channels with respect to carbonaceous fragments. Expand


Polycyclic aromatic hydrocarbon processing in interstellar shocks
Context. PAHs appear to be an ubiquitous interstellar dust component but the effects of shocks waves upon them have never been fully investigated. Aims. We study the effects of energetic (≈0.01−1Expand
Cosmic-ray ionization of molecular clouds
Context. Low-energy cosmic rays are a fundamental source of ionization for molecular clouds, influencing their chemical, thermal, and dynamical evolution. Aims. The purpose of this work is to exploreExpand
Polycyclic aromatic hydrocarbon processing in a hot gas
Context. PAHs are thought to be a ubiquitous and important dust component of the interstellar medium. However, the effects of their immersion in a hot (post-shock) gas have never before been fullyExpand
The Implications of a High Cosmic-Ray Ionization Rate in Diffuse Interstellar Clouds
Diffuse interstellar clouds show large abundances of H+ 3 which can only be maintained by a high ionization rate of H2. Cosmic rays are the dominant ionization mechanism in this environment, so theExpand
Secondary Antiprotons and Propagation of Cosmic Rays in the Galaxy and Heliosphere
High-energy collisions of cosmic-ray nuclei with interstellar gas are believed to be the mechanism producing the majority of cosmic-ray antiprotons. Because of the kinematics of the process, they areExpand
Interstellar Polycyclic Aromatic Hydrocarbon Molecules
Large polycyclic aromatic hydrocarbon (PAH) molecules carry the infrared (IR) emission features that dominate the spectra of most galactic and extragalactic sources. This review surveys the observedExpand
Cosmic-ray lifetime in the galaxy: Experimental results and models
AbstractThe containment lifetime of the cosmic radiation is a crucial parameter in the investigation of the cosmic-ray origin and plays an important role in the dynamics of the Galaxy. The separationExpand
Clusters of Galaxies as Storage Room for Cosmic Rays
It is demonstrated that clusters of galaxies are able to keep cosmic rays for a time exceeding the age of the universe. This phenomenon reveals itself by the production of the diffuse flux ofExpand
On the escape of cosmic rays from radio galaxy cocoons
The escape rate of cosmic ray (CR) particles from radio galaxy cocoons is a problem of high astrophysical relevance: e.g. if CR electrons are stored for long times in the dilute relativistic mediumExpand
Production and propagation of cosmic ray positrons and electrons
We have made a new calculation of the cosmic-ray secondary positron spectrum using a diffusive halo model for Galactic cosmic-ray propagation. The code computes self-consistently the spectra ofExpand