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Related papers: Positron Annihilation on Polycyclic Aromatic Hydro…

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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

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

Polycyclic aromatic hydrocarbon (PAH) emission has been found in both starbursts and modestly starforming galaxies, but the relation between starforming activity and PAH luminosity is still a matter of debate. The different correlation…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Martin Haas , Christian Leipski , Ralf Siebenmorgen , Helmut Meusinger , Holger Drass , Rolf Chini

Polycyclic Aromatic Hydrocarbons (PAHs) have long been invoked in the study of interstellar and protostellar sources, but the unambiguous identification of any individual PAH has proven elusive until very recently. As a result, the…

The gas-phase abundances of deuterium (D) in the local interstellar medium (ISM) exhibit considerable regional variations. Particularly, in some regions the gas-phase D abundances are substantially lower than the primordial D abundance…

Astrophysics of Galaxies · Physics 2025-03-05 Xuejuan Yang , Aigen Li

Polycyclic aromatic hydrocarbons (PAHs) are responsible for a variety of near- and mid-infrared spectral features in Galactic and extragalactic sources. A feature at 1.05 $\mu$m arising from electronic transitions in PAH cations is…

Astrophysics of Galaxies · Physics 2026-03-25 Dennis Lee , Brandon S. Hensley , Tzu-Ching Chang , Olivier Doré

The cosmic-ray ionization rate ($\zeta$, s$^{-1}$) plays an important role in the interstellar medium. It controls ion-molecular chemistry and provides a source of heating. Here we perform a grid of calculations using the spectral synthesis…

Astrophysics of Galaxies · Physics 2021-01-13 Gargi Shaw , G. J. Ferland

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…

We combined mapping-mode mid-infrared Spitzer spectra with complementary infrared imaging to perform a spatially resolved study of polycyclic aromatic hydrocarbons (PAHs) emission from the central regions of 66 nearby galaxies, roughly…

Astrophysics of Galaxies · Physics 2022-12-13 Lulu Zhang , Luis C. Ho , Aigen Li

We present a new methodology for simulating mid-infrared emission from polycyclic aromatic hydrocarbons (PAHs) in galaxy evolution simulations. To do this, we combine theoretical models of PAH emission features as they respond to varying…

Superhydrogenated polycyclic aromatic hydrocarbons (PAHs) may be present in H-rich and ultraviolet-poor benign regions. The addition of excess H atoms to PAHs converts the aromatic bonds into aliphatic bonds, the strongest of which falls…

Astrophysics of Galaxies · Physics 2020-03-04 X. J. Yang , Aigen Li , R. Glaser

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…

Polycyclic aromatic hydrocarbons (PAHs) are fundamental to understanding the interstellar medium (ISM) of several astrophysical objects. Normally present in Starburst (SB) galaxies, they have also been more frequently detected in active…

It has been an unanswered question how many dusty galaxies have been undetected from the state-of-the-art observational surveys. JWST enables us to detect faint IR galaxies that have prominent polycyclic aromatic hydrocarbon (PAH) features…

Interstellar polycyclic aromatic hydrocarbons (PAHs) are strongly affected by the absorption of vacuum ultraviolet (VUV) photons in the interstellar medium (ISM), yet the branching ratio between ionization and fragmentation is poorly…

We calibrate the integrated luminosity from the polycyclic aromatic hydrocarbon (PAH) features at 6.2\micron, 7.7\micron\ and 11.3\micron\ in galaxies as a measure of the star-formation rate (SFR). These features are strong (containing as…

Astrophysics of Galaxies · Physics 2016-02-17 Heath V. Shipley , Casey Papovich , George H. Rieke , Michael J. I. Brown , John Moustakas

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 ubiquitous in astrophysical environments, as revealed by their pronounced emission features at 3.3, 6.2, 7.7, 8.6, 11.3, and 12.7 $\mu$m commonly ascribed to the C--H and C--C vibrational modes.…

Astrophysics of Galaxies · Physics 2017-07-19 Han Zhang , Charles M. Telesco , Thiem Hoang , Aigen Li , Eric Pantin , Christopher M. Wright , Dan Li , Peter Barnes

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