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Related papers: Polycylcic Aromatic Hydrocarbons (PAH's) in dense …

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Polycyclic aromatic hydrocarbons (PAHs) are of great astrochemical and astrobiological interest due to their potential to form prebiotic molecules. We analyse the 7.7 and 8.6 ${\mu}$m PAH bands in 126 predominantly starburst-dominated…

Mixtures of polycylic aromatic hydrocarbons (PAHs) have been produced by means of laser pyrolysis. The main fraction of the extracted PAHs were primarily medium-sized, up to a maximum size of 38 carbon atoms per molecule. The use of…

Instrumentation and Methods for Astrophysics · Physics 2011-01-24 M. Steglich , C. Jäger , G. Rouillé , F. Huisken , H. Mutschke , Th. Henning

We present results of mid-infrared spectroscopic mapping observations of six star-forming regions in the Small Magellanic Cloud from the Spitzer Spectroscopic Survey of the SMC (S4MC). We detect the mid-IR emission from polycyclic aromatic…

In order to find out capable molecular source of astronomically well observed infrared (IR) spectrum, asymmetric molecular configuration polycyclic aromatic hydrocarbon (PAH) was analyzed by the density functional theory (DFT) analysis.…

Astrophysics of Galaxies · Physics 2015-10-27 Norio Ota

Polycyclic aromatic hydrocarbons (PAHs) are key dust components in galaxies and play a fundamental role in the physics of the interstellar medium (ISM), yet their response to AGN feedback remains debated. We present a spatially resolved…

Polycyclic Aromatic Hydrocarbons (PAHs) are believed to be the small-size tail of the interstellar carbonaceous dust grain population. Their vibrational emission is the most widely accepted source of the aromatic near-infrared features, and…

Astrophysics of Galaxies · Physics 2015-08-21 Yacine Ali-Haïmoud , Laura Pérez , Ronald Maddalena , Anish Roshi

We present recent UV laboratory spectra of various polycyclic aromatic hydrocarbons (PAHs) and explore the potential of these molecules as carriers of the DIBs. From a detailed comparison of gas-phase and Ne-matrix absorption spectra of…

Astrophysics of Galaxies · Physics 2015-05-27 R. Gredel , Y. Carpentier , G. Rouille , M. Steglich , F. Huisken , Th. Henning

We present a charge distribution based model that computes the infrared spectrum of polycyclic aromatic hydrocarbon (PAH) molecules using recent measurements or quantum chemical calculations of specific PAHs. The model is applied to a…

Astrophysics of Galaxies · Physics 2022-06-15 Ameek Sidhu , A. G. G. M. Tielens , Els Peeters , Jan Cami

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

Aims: We explore the relation between charge state of polycyclic aromatic hydrocarbons (PAHs) and extinction curve morphology. Methods: We fit extinction curves with a dust model including core-mantle spherical particles of mixed chemical…

Astrophysics · Physics 2009-11-13 C. Cecchi-Pestellini , G. Malloci , G. Mulas , C. Joblin , D. A. Williams

A combined mid-IR spectrum of five colliding-wind, massive, dust-producing Population I Wolf-Rayet (WR) binaries shows a wealth of absorption and emission details coming from the circumstellar dust envelopes, as well as from the…

Solar and Stellar Astrophysics · Physics 2017-04-19 S. V. Marchenko , A. F. J. Moffat

We have investigated the role of molecular anion chemistry in pseudo-time dependent chemical models of dark clouds. With oxygen-rich elemental abundances, the addition of anions results in a slight improvement in the overall agreement…

Astrophysics of Galaxies · Physics 2009-07-22 Catherine Walsh , Nanase Harada , Eric Herbst , T. J. Millar

As images and spectra from ISO and Spitzer have provided increasingly higher-fidelity representations of the mid-infrared (MIR) and Polycyclic Aromatic Hydrocarbon (PAH) emission from galaxies and galactic and extra-galactic regions, more…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Daniela Calzetti

Intensity ratios of aromatic emission features are widely used to diagnose the size and ionization state of polycyclic aromatic hydrocarbons (PAHs) in astronomical environments. However, PAHs are known to typically carry aliphatic side…

Astrophysics of Galaxies · Physics 2026-05-12 Zhuang Zhang , Yong Zhang

Recent detections of aromatic species in dark molecular clouds suggest formation pathways may be efficient at very low temperatures and pressures, yet current astrochemical models are unable to account for their derived abundances, which…

Astrophysics of Galaxies · Physics 2024-10-22 Alex N. Byrne , Ci Xue , Ilsa R. Cooke , Michael C. McCarthy , Brett A. McGuire

To investigate the gas-phase hydrogenation processes of large, astronomically relevant cationic polycyclic aromatic hydrocarbon (PAH) molecules under the interstellar environments, the ion-molecule collision reaction between six PAH cations…

Astrophysics of Galaxies · Physics 2024-05-28 Lijun Hua , Xiaoyi Hu , Junfeng Zhen , Xuejuan Yang

The search for large polycyclic aromatic hydrocarbons (PAHs) with over 100 carbon atoms is crucial to resolving the origin of unidentified infrared emission (UIE) bands. These bands are commonly observed in nebulae and the interstellar…

Astrophysics of Galaxies · Physics 2025-08-22 Yi Shao , Yong Zhang , Xu-Jia Ouyang , Chuan-Peng Zhang

As a part of interstellar dust, polycyclic aromatic hydrocarbons (PAHs) are processed by the interaction with vacuum ultraviolet (VUV) photons that are emitted by hot young stars. This interaction leads to the emission of the well-known…

We present a comparison of observed polycyclic aromatic hydrocarbon (PAH) feature ratios in 19 nearby galaxies with a grid of theoretical expectations for near- and mid-infrared dust emission. The PAH feature ratios are drawn from Cycle 1…