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Related papers: Rotational spectroscopy of interstellar PAHs

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The amount of deuterium locked up in polycyclic aromatic hydrocarbons (PAHs) has to date been an uncertain value. We present a near-infrared (NIR) spectroscopic survey of HII regions in the Milky Way, Large Magellanic Cloud (LMC), and Small…

Astrophysics of Galaxies · Physics 2016-01-27 Kirstin D. Doney , Alessandra Candian , Tamami Mori , Takashi Onaka , A. G. G. M. Tielens

We present 5-20 micron spectral maps of the reflection nebula NGC2023 obtained with the Infrared Spectrograph SL and SH modes on board the Spitzer Space Telescope which reveal emission from polycyclic aromatic hydrocarbons (PAHs), C60, and…

It is very important to identify carrier molecules of astronomical interstellar infrared spectrum (IR) to understand chemical evolution step of polycyclic aromatic hydrocarbon (PAH) in the universe. In our previous study, it was suggested…

Astrophysics of Galaxies · Physics 2018-01-22 Norio Ota

Polycyclic Aromatic Hydrocarbon (PAH) molecules have been long proposed to be a major carrier of 'Unidentified Infrared' (UIR) emission bands that have been observed ubiquitously in various astrophysical environments. These molecules can…

Astrophysics of Galaxies · Physics 2017-11-28 Mridusmita Buragohain , Amit Pathak , Peter Sarre , Takashi Onaka , Itsuki Sakon

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…

Observationally, the interstellar gas-phase abundance of deuterium (D) is considerably depleted and the missing D atoms are often postulated to have been locked up into carbonaceous solids and polycyclic aromatic hydrocarbon (PAH)…

Astrophysics of Galaxies · Physics 2021-08-04 X. J. Yang , Aigen Li , C. Y. He , R. Glaser

Infrared emission features at 3.3, 6.2, 7.7, 8.6, and 11.2 $\mu$m, attributed to polycyclic aromatic hydrocarbons, show variations in relative intensity, shape, and peak position. These variations depend on the physical conditions of the…

Astrophysics of Galaxies · Physics 2021-11-24 C. Knight , E. Peeters , M. Wolfire , D. J. Stock

As the inventory of interstellar molecules continues to grow, the gulf between small species, whose individual rotational lines can be observed with radio telescopes, and large ones, such as polycyclic aromatic hydrocarbons (PAHs) best…

The formation of polycyclic aromatic hydrocarbons (PAHs) and their methyl derivatives occurs mainly in the dust shells of asymptotic giant branch (AGB) stars. The bands at 3.3 and 3.4 $\mu$m, observed in infrared emission spectra of several…

Solar and Stellar Astrophysics · Physics 2016-04-20 T. Monfredini , F. Fantuzzi , M. A. C. Nascimento , W. Wolff , H. M. Boechat-Roberty

We explore the relationships between the Polycyclic Aromatic Hydrocarbon (PAH) feature strengths, mid-infrared continuum luminosities, far-infrared spectral slopes, optical spectroscopic classifications, and silicate optical depths within a…

Functionalized polcyclic aromatic hydrocarbons (PAHs) are an interesting class of molecules in which the electronic state of the graphene-like hydrocarbon part is tuned by the functional group. Searching for new types of donor and acceptor…

The so-called aromatic infrared bands are attributed to emission of polycyclic aromatic hydrocarbons. The observed variations toward different regions in space are believed to be caused by contributions of different classes of PAH…

Astrophysics of Galaxies · Physics 2021-04-14 Shreyak Banhatti , Julianna Palotás , Pavol Jusko , Britta Redlich , Jos Oomens , Stephan Schlemmer , Sandra Brünken

The PAH model predicts many weak emission features in the 1-5 $\mu$m region that can resolve significant questions that it has faced since its inception in the mid-80s. These features contain fundamental information about the PAH population…

Astrophysics of Galaxies · Physics 2024-03-05 L. J. Allamandola , C. Boersma , T. J. Lee , J. D. Bregman , P. Temi

Polycyclic aromatic hydrocarbon (PAH) ions are crucial intermediates in interstellar chemistry and may play a key role in the infrared emission features observed in space. Here, we investigate the infrared spectra of the indenyl…

The aromatic infrared Bands (AIBs) dominate the mid-infrared spectra of many galactic and extragalactic sources. These AIBs are generally attributed to fluorescent emission from aromatic molecules. Unified efforts from experimentalists and…

Astrophysics of Galaxies · Physics 2024-08-26 P. Sundararajan , A. Candian , J. Kamer , H. Linnartz , A. G. G. M. Tielens

In this work we report on high-resolution IR absorption studies that provide a detailed view on how the peripheral structure of irregular polycyclic aromatic hydrocarbons (PAHs) affects the shape and position of their 3 {\mu}m absorption…

Although H$_{2}$ is the simplest and the most abundant molecule in the Universe, its formation in the interstellar medium, especially in the photodissociation regions is far from being fully understood. According to suggestions, the…

Astrophysics of Galaxies · Physics 2023-07-26 David P. Jelenfi , Anita Schneiker , Attila Tajti , Gabor Magyarfalvi , Gyorgy Tarczay

The physical mechanism producing Anomalous Microwave Emission (AME) has been an unresolved puzzle for close to 30 years. One candidate mechanism is rotational emission from polycyclic aromatic hydrocarbons (PAHs) which can have the…

Astrophysics of Galaxies · Physics 2026-01-29 Dylan M. Pare , David T. Chuss , Danielle Sponseller , Brandon Hensley , Alan Kogut

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