Coulomb explosion of polycyclic aromatic hydrocarbons induced by heavy cosmic rays: carbon chains production rates

M Chabot,T Pino,K Béroff,E Dartois

doi:10.1088/1742-6596/1412/15/152034

Abstract

SynopsisThe interstellar medium contains both polycyclic aromatic hydrocarbons and cosmic rays. The frontal impact of a single heavy cosmic ray strips out many electrons. The highly charged species then relax by multi-fragmentation, potentially feeding the interstellar medium with hydrocarbon chains. We model both ionization(s) and fragmentation processes and compute the fragments production rates of particular interest for astrophysical models.

Highlights

In the Interstellar Medium (ISM), carbon atoms are locked into many different structures
In this article we report on the coulomb explosion of highly positively charged polycyclic aromatic hydrocarbons (PAH) induced by the interstellar Cosmic Rays (CR) leading to the formation of long carbon chains
We modeled the CR induced multiionization cross sections of interstellar PAHs

Summary

Introduction

In the Interstellar Medium (ISM), carbon atoms are locked into many different structures. The gas phase synthesis of medium size carbon based molecules (i.e. with more than 2-4 carbon atoms) by a bottom-up pure gas phase chemistry faces difficulties in matching the observed abundances (Cuadrado et al 2015; Guzman et al 2015; Pety et al 2012, 2005). These molecules may alternatively be produced by fragmenting the reservoirs of large polyaromatic molecules, and/or interstellar solids with UV photons, shocks and Cosmic Rays

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Results

Conclusion