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Related papers: Polycyclic aromatic hydrocarbon processing in inte…

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We present spatial distribution of polycyclic aromatic hydrocarbons and ionized gas within the Galactic giant HII region NGC3603. Using the IRS instrument on board the Spitzer Space Telescope, we study in particular the PAH emission…

Astrophysics · Physics 2009-06-23 V. Lebouteiller , B. Brandl , J. Bernard-Salas , D. Devost , J. R. Houck

Low-resolution, mid-infrared Spitzer/IRS spectral maps are presented for three nearby, low-metallicity dwarf galaxies (NGC 55, NGC 3109 and IC 5152) for the purpose of examining the spatial distribution and variation of polycyclic aromatic…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Korey Haynes , John M. Cannon , Evan D. Skillman , Dale C. Jackson , Robert D. Gehrz

Small organic molecules are thought to provide building blocks for the formation of complex interstellar polycyclic aromatic hydrocarbons (PAHs). However, the underlying chemical mechanisms remain unclear, particularly concerning the role…

Astrophysics of Galaxies · Physics 2020-09-17 Meriem Hanine , Zhisen Meng , Shiru Lu , Peng Xie , Sylvain Picaud , Michel Devel , Zhao Wang

The grid of the models of radiative shock waves propagating through partially ionized hydrogen gas with temperature 3000K <= T_1 <= 8000K and density 10^{-12} gm/cm^3 <= \rho_1 <= 10^{-9}gm/cm^3 is computed for shock velocities 20 km/s <=…

Astrophysics · Physics 2009-11-06 Yu. A. Fadeyev , D. Gillet

Using the AKARI, Wide-field Infrared Survey Explorer (WISE), Infrared Astronomical Satellite (IRAS), Sloan Digital Sky Survey (SDSS) and Hubble Space Telescope (HST) data, we investigated the relation of polycyclic aromatic hydrocarbon…

Polycyclic aromatic hydrocarbon (PAH) molecules, as revealed by the distinctive set of emission bands at 3.3, 6.2, 7.7, 8.6, 11.3 and 12.7 $\mu$m characteristic of their vibrational modes, are abundant and widespread throughout the…

Astrophysics of Galaxies · Physics 2020-03-25 Aigen Li

In Spitzer observations of Tauri stars and their disks, PAH features are detected in less than 10% of the objects, although the stellar photosphere is sufficiently hot to excite PAHs. To explain the deficiency, we discuss PAH destruction by…

Astrophysics of Galaxies · Physics 2009-11-24 Ralf Siebenmorgen , Endrik Krügel

The abundance of polycyclic aromatic hydrocarbons (PAHs) in low- and high-metallicity galaxies has been widely discussed since the time when detailed infrared data for extragalactic objects were first obtained. On the scales of entire…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 M. S. Khramtsova , D. S. Wiebe , P. A. Boley , Ya. N. Pavlyuchenkov

The high interstellar abundances of polycyclic aromatic hydrocarbons (PAHs) and their size distribution are the result of complex chemical processes implying dust, UV radiation, and the main gaseous components (H, C+, and O). These…

Astrophysics of Galaxies · Physics 2021-07-07 A. Omont , H. F. Bettinger

The infrared (IR) emission of polycyclic aromatic hydrocarbons (PAHs) permeates our universe; astronomers have detected the IR signatures of PAHs around many interstellar objects. The IR emission of interstellar PAHs differs from their…

Astrophysics of Galaxies · Physics 2018-10-05 Cameron J. Mackie , Tao Chen , Alessandra Candian , Timothy J. Lee , Alexander G. G. M. Tielens

Depending on whom you ask, PAHs are either the smallest dust particles or the largest gas-phase molecules in space. Whether referred to as gas or dust, these PAHs can contain up to 20% of the total cosmic carbon abundance and as such also…

Solar and Stellar Astrophysics · Physics 2015-05-20 Inga Kamp

Polycyclic aromatic hydrocarbons (PAHs) have been detected in numerous circumstellar discs. We propose the continuous processing of PAHs through clustering, adsorption on dust grains, and their reverse-processes as key mechanisms to reduce…

Earth and Planetary Astrophysics · Physics 2023-07-05 K. Lange , C. Dominik , A. G. G. M. Tielens

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 maps tracing the fraction of dust in the form of polycyclic aromatic hydrocarbons (PAHs) in IC 5332, NGC 628, NGC 1365, and NGC 7496 from JWST/MIRI observations. We trace the PAH fraction by combining the F770W ($7.7~\mu$m) and…

I summarize the results of two recent studies, based on ISO and Spitzer mid-IR spectra of galaxies and Galactic regions, aimed at understanding the origins of the variations of the aromatic features among and inside galaxies. I show that…

Astrophysics · Physics 2007-05-23 F. Galliano

Virtually all detailed gas-phase models of the chemistry of dense interstellar clouds exclude polycyclic aromatic hydrocarbons (PAH's). This omission is unfortunate because from the few studies that have been done on the subject, it is…

Astrophysics · Physics 2009-11-13 Valentine Wakelam , Eric Herbst

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

Infrared (IR) emission spectra are calculated for dust composed of mixtures of amorphous silicate and graphitic grains, including varying amounts of polycyclic aromatic hydrocarbon (PAH) particles. The models are constrained to reproduce…

Astrophysics · Physics 2008-11-26 B. T. Draine , Aigen Li

Only 8% of the protoplanetary discs orbiting a T Tauri star show emission features of polycyclic aromatic hydrocarbons (PAHs). As PAHs are strong absorbers of UV radiation, they contribute to the heating of the discs photosphere, shielding…

Earth and Planetary Astrophysics · Physics 2025-10-01 K. Lange , C. Dominik , A. G. G. M. Tielens

The exact nature of the 2175 Angstrom extinction bump, the strongest spectroscopic absorption feature superimposed on the interstellar extinction curve, remains unknown ever since its discovery in 1965. Popular candidate carriers for the…

Astrophysics of Galaxies · Physics 2023-08-10 Qi Lin , X. J. Yang , Aigen Li