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Related papers: Mapping PAH sizes in NGC 7023 with SOFIA

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Polycyclic aromatic hydrocarbons (PAHs) and carbonaceous dust have been observed in clumpy circumstellar environments, yet their formation and evolutionary pathways in such environments remain elusive. We aim to characterize the PAH…

The detection of a new 16.4 micron emission feature in the ISO-SWS spectra of NGC 7023, M17, and the Orion Bar is reported. Previous laboratory experiments measured a mode near this wavelength in spectra of PAHs (Polycyclic Aromatic…

Astrophysics · Physics 2007-05-23 C. Moutou , L. Verstraete , A. Leger , K. Sellgren , W. Schmidt

We present a new method to accurately describe the ionization fraction and the size distribution of polycyclic aromatic hydrocarbons (PAHs) within astrophysical sources. To this purpose, we have computed the mid-infrared emission spectra of…

Astrophysics of Galaxies · Physics 2020-03-18 A. Maragkoudakis , E. Peeters , A. Ricca

The mid-IR spectra of six large, irregular PAHs with formulae (C84H24 - C120H36) have been computed using Density Functional Theory (DFT). Trends in the dominant band positions and intensities are compared to those of large, compact PAHs as…

Astrophysics of Galaxies · Physics 2012-08-27 Charles W. Bauschlicher, , Els Peeters , Louis J. Allamandola

We present 15-20 um spectral maps towards the reflection nebula NGC2023 obtained with the Infrared Spectrograph in short-wavelength, high-resolution mode on board the Spitzer Space Telescope. These spectra reveal emission from PAHs, C60,…

Astrophysics of Galaxies · Physics 2015-06-03 Els Peeters , Alexander G. G. M. Tielens , Louis J. Allamandola , Mark G. Wolfire

We report new properties of the 11 and 12.7 {\mu}m emission complexes of polycyclic aromatic hydrocarbons (PAHs) by applying a Gaussian-based decomposition technique. Using high-resolution \textit{Spitzer} Space Telescope data, we study in…

Astrophysics of Galaxies · Physics 2016-06-29 M. J. Shannon , D. J. Stock , E. Peeters

We present SWS and LWS ISO observations towards a strip across the photodissociation region (PDR) in the reflection nebula NGC 7023. SWS02 and LWS01 spectra have been taken towards the star and the brightest infrared filaments located NW…

Astrophysics · Physics 2007-05-23 A. Fuente , J. Martin-Pintado , N. J. Rodriguez-Fernandez , J. Cernicharo , M. Gerin

We present $Spitzer$/IRS mid-infrared spectral maps of the Galactic star-forming region M17 as well as IRSF/SIRIUS Br$\gamma$ and Nobeyama 45-m/FOREST $^{13}$CO ($J$=1--0) maps. The spectra show prominent features due to polycyclic aromatic…

We present 5--14~$\mu$m spectra at two different positions across the Orion Bar photodissociation region (PDR) obtained with the Infrared Spectrograph onboard the Spitzer Space Telescope and 3.3~$\mu$m PAH observations obtained with the…

Astrophysics of Galaxies · Physics 2021-11-03 C. Knight , E. Peeters , A. G. G. M. Tielens , W. D. Vacca

We present a focused study of radially-resolved varying PAH emission in the low-luminosity AGN-host NGC 4138 using deep Spitzer/IRS spectral maps. Using new model PAH spectra, we investigate whether these variations could be associated with…

Astrophysics of Galaxies · Physics 2024-04-24 G. P. Donnelly , J. D. T. Smith , B. T. Draine , A. Togi , T. S. -Y. Lai , L. Armus , D. A. Dale , V. Charmandaris

We have analyzed the temperature, velocity and density of H2 gas in NGC 7023 with a high-resolution near-infrared spectrum of the northwestern filament of the reflection nebula. By observing NGC 7023 in the H and K bands at R ~ 45,000 with…

The aromatic infrared bands (AIBs) observed in the mid infrared spectrum are attributed to Polycyclic Aromatic Hydrocarbons (PAHs). We observe the NGC 7023-North West (NW) PDR in the mid-infrared (10 - 19.5 micron) using the Infrared…

Astrophysics of Galaxies · Physics 2015-05-28 M. J. F. Rosenberg , O. Berné , C. Boersma , L. J. Allamandola , A. G. G. M Tielens

Extended Red Emission (ERE) was recently attributed to the photo-luminescence of either doubly ionized Polycyclic Aromatic Hydrocarbons (PAH$^{++}$), or charged PAH dimers. We analysed the visible and mid-infrared (mid-IR) dust emission in…

Astrophysics · Physics 2008-01-23 O. Berne , C. Joblin , M. Rapacioli , J. Thomas , J. -C. Cuillandre , Y. Deville

We present the analysis of the Polycyclic Aromatic Hydrocarbon (PAH) spectra of a sample of 92 typical star forming galaxies at 0.03 < z < 0.2 observed with the Spitzer IRS. We compare the relative strengths of PAH emission features with…

We investigate the mid-infrared (IR) emission in the Orion Bar photodissociation region, using archival photometric and spectroscopic observations from UKIRT, Spitzer, ISO, and SOFIA telescopes. Specifically, we consider flux densities of…

Astrophysics of Galaxies · Physics 2021-11-11 Maria S. Murga , Maria S. Kirsanova , Dmitry S. Wiebe , Paul A. Boley

We have carried out a detailed analysis of the 3.4 micron spectral feature arising from Polycyclic Aromatic Hydrocarbons (PAH), using JWST archival data. For the first time in an external galaxy (NGC 6240), we have identified two distinct…

In the present contribution, I summarize a systematic study of ISO and Spitzer mid-IR spectra of Galactic regions and star forming galaxies. This study quantifies the relative variations of the main aromatic features inside spatially…

Astrophysics · Physics 2008-02-19 F. Galliano

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

Polycyclic Aromatic Hydrocarbons (PAHs) are carbon-based molecules resulting from the union of aromatic rings and related species, which are likely responsible for strong infrared emission features (3.3, 6.2, 7.7, 8.6, 11.3 and 12.7…

Astrophysics of Galaxies · Physics 2021-11-05 I. García-Bernete , D. Rigopoulou , A. Alonso-Herrero , M. Pereira-Santaella , P. F. Roche , B. Kerkeni