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Related papers: Dissociative photoionization of polycyclic aromati…

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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 fully investigated. Aims: We study the effects of…

Astrophysics of Galaxies · Physics 2015-05-14 E. R. Micelotta , A. P. Jones , A. G. G. M. Tielens

Interstellar Polycyclic Aromatic Hydrocarbon (PAH) molecules exist in diverse forms depending on the local physical environment. Formation of ionized PAHs (anions and cations) is favourable in the extreme conditions of the ISM. Besides in…

Astrophysics of Galaxies · Physics 2017-12-27 Mridusmita Buragohain , Amit Pathak , Peter Sarre , Nand Kishor Gour

We examine the annihilation of positrons on polycyclic aromatic hydrocarbon (PAH) molecules in interstellar medium conditions. We estimate the annihilation rates of positrons on PAHs by a semi-empirical approach. We show that PAHs can play…

High Energy Astrophysical Phenomena · Physics 2015-05-14 N. Guessoum , P. Jean , W. Gillard

Polycyclic aromatic hydrocarbons (PAHs) appear to be ubiquitous in terrestrial atmosphere as well as in the interstellar medium (ISM). In the astrophysical context presence of PAHs is interpreted by the observations of mid-IR emission bands…

Chemical Physics · Physics 2019-03-26 Rashmi Singh , Shantanu Rastogi

We report on a common fragment ion formed during the electron-ionization-induced fragmentation of three different three-ring polycyclic aromatic hydrocarbons (PAHs), fluorene (C$_{13}$H$_{10}$), 9,10-dihydrophenanthrene (C$_{14}$H$_{12}$),…

Astrophysics of Galaxies · Physics 2020-03-27 A. Petrignani , M. Vala , J. R. Eyler , A. G. G. M. Tielens , G. Berden , A. F. G. van der Meer , B. Redlich , J. Oomens

Polycyclic aromatic hydrocarbons (PAHs) and fullerenes play a major role in the physics and chemistry of the interstellar medium. Based on a number of recent experimental and theoretical investigations we developed a model in which PAHs are…

Astrophysics of Galaxies · Physics 2022-11-09 M. S. Murga , V . V. Akimkin , D. S. Wiebe

We present a study for a sample of galaxies with active nuclei to characterize the main type of PAH molecules present in these objects and the local physical conditions of their irradiating sources, as well as the characteristics of the…

Planet-forming disks of gas and dust around young stars contain polycyclic aromatic hydrocarbons (PAHs). We aim to characterize how the charge state of PAHs can be used as a probe of flows of gas through protoplanetary gaps. In this…

Solar and Stellar Astrophysics · Physics 2015-06-18 K. M. Maaskant , M. Min , L. B. F. M. Waters , A. G. G. M. Tielens

[Abridged] The ionization of polycyclic aromatic hydrocarbons (PAHs), by ultraviolet (UV) photons from massive stars is expected to account for a large fraction of the heating of neutral gas in galaxies. Evaluation of this proposal,…

Astrophysics of Galaxies · Physics 2022-12-14 O. Berné , S. Foschino , F. Jalabert , C. Joblin

Polycyclic Aromatic Hydrocarbons (PAHs) are considered as a major constituent of interstellar dust. They have been proposed as the carriers of the Aromatic Infrared Bands (AIBs) observed in emission in the mid-IR. They likely have a…

Astrophysics of Galaxies · Physics 2009-04-22 C. Joblin , O. Berne , A. Simon , G. Mulas

We study whether polycyclic aromatic hydrocarbons (PAHs) can be a weighty source of small hydrocarbons in photo-dissociation regions (PDRs). We modeled the evolution of 20 specific PAH molecules in terms of dehydrogenation and destruction…

Astrophysics of Galaxies · Physics 2020-07-15 M. S. Murga , M. S. Kirsanova , A. I. Vasyunin , Ya. N. Pavlyuchenkov

The electronic spectra of gas-phase cationic polycyclic aromatic hydrocarbons (PAHs), trapped in the Fourier Transform Ion Cyclotron Resonance cell of the PIRENEA experiment, have been measured by multiphoton dissociation spectroscopy in…

Chemical Physics · Physics 2015-03-13 F. Useli-Bacchitta , A. Bonnamy , G. Mulas , G. Malloci , D. Toublanc , C. Joblin

We observationally investigate the relation between the photoelectric heating efficiency in PDRs and the charge of PAHs, which are considered to play a key role in photoelectric heating. Using PACS onboard Herschel, we observed six PDRs…

We have obtained new STIS/HST spectra to search for structure in the ultraviolet interstellar extinction curve, with particular emphasis on a search for absorption features produced by polycyclic aromatic hydrocarbons (PAHs). The presence…

Computational study of polycyclic aromatic hydrocarbons (PAHs) with phenyl side group substituted at different positions is reported. The infrared spectral variations due to the position of phenyl substitution, ionization state and the size…

Astrophysics of Galaxies · Physics 2022-11-28 Anju Maurya , Rashmi Singh , Shantanu Rastogi

Infrared (IR) absorption spectra of individual polycyclic aromatic hydrocarbons (PAHs) containing methyl (-CH3), methylene (>CH2), or diamond-like *CH groups and IR spectra of mixtures of methylated and hydrogenated PAHs prepared by gas…

Context: Cosmic rays are present in almost all phases of the ISM. PAHs and cosmic rays represent an abundant and ubiquitous component of the interstellar medium. However, the interaction between them has never before been fully…

Astrophysics of Galaxies · Physics 2015-05-20 E. R. Micelotta , A. P. Jones , A. G. G. M. Tielens

The presence of methyl alcohol or methanol (CH$_3$OH) in several astrophysical environments has been characterized by its high abundance that depends on both the production rate and the destruction rate. In the present work, the…

Astrophysics · Physics 2008-11-26 S. Pilling , R. Neves , A. C. F. Santos , H. M. Boechat-Roberty

We report the results of a search for emission features from interstellar deuterated polycyclic aromatic hydrocarbons (PAHs) in the 4um region with the Infrared Camera (IRC) onboard AKARI. No significant excess emission is seen in 4.3-4.7um…

Astrophysics of Galaxies · Physics 2015-06-17 Takashi Onaka , Tamami I. Mori , Itsuki Sakon , Ryou Ohsawa , Hidehiro Kaneda , Yoko Okada , Masahiro Tanaka