PAH Clusters as Interstellar Very Small Grains

Roser, Joseph E ; Ricca, Alessandra

关键词: INTERSTELLAR MATTER;    POLYCYCLIC AROMATIC HYDROCARBONS;    INFRARED RADIATION;    INFRARED SPECTROSCOPY;    ARGON;    COSMIC DUST;    STOCHASTIC PROCESSES;   

RP-ID  :  ARC-E-DAA-TN73119

学科分类：天体物理学

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来源: NASA Technical Reports Server

【 摘 要 】

PAH clusters are one candidate species for the interstellar "very small grains" or "VSGs", i.e., dust grains small enough to be stochastically heated and contribute to the aromatic infrared emission bands (AIBs). This possibility motivated laboratory experiments on the infrared spectroscopy of PAH clusters using matrix isolation spectroscopy. The spectral shifts due to PAH clustering in argon matrices provide clues for the AIB contribution from PAH clusters in the interstellar medium. Here we review results from a number of small PAH species, extrapolation to the much larger PAHs believed to be present in the interstellar medium, and the implications for a PAH cluster contribution to the VSG population.