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Using a merged beams apparatus we have measured the associative detachment (AD) reaction of ${\rm H}^- + {\rm H} \to {\rm H}_2 + e^-$ for relative collision energies up to \textit{E}$_{\rm{r}} \leq 4.83$ eV. These data extend above the 1 eV…

Atomic Physics · Physics 2015-05-30 K. A. Miller , H. Bruhns , J. Eliášek , M. Čížek , H. Kreckel , X. Urbain , D. W. Savin

The study of the formation of molecular hydrogen on low temperature surfaces is of interest both because it allows to explore elementary steps in the heterogeneous catalysis of a simple molecule and because of the applications in…

Chemical Physics · Physics 2008-11-21 G. Vidali , V. Pirronello , L. Li , J. Roser , G. Manico , R. Mehl , A. Lederhendler , H. B. Perets , J. R. Brucato , O. Biham

We report on a common fragment ion formed during the electron-ionization-induced fragmentation of three different three-ring polycyclic aromatic hydrocarbons (PAHs), fluorene (C$_{13}$H$_{10}$), 9,10-dihydrophenanthrene (C$_{14}$H$_{12}$),…

Astrophysics of Galaxies · Physics 2020-03-27 A. Petrignani , M. Vala , J. R. Eyler , A. G. G. M. Tielens , G. Berden , A. F. G. van der Meer , B. Redlich , J. Oomens

H2 pure-rotational emission lines are detected from warm (100-1500 K) molecular gas in 17/55 (31% of) radio galaxies at redshift z<0.22 observed with the Spitzer IR Spectrograph. The summed H2 0-0 S(0)-S(3) line luminosities are…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Patrick Ogle , Francois Boulanger , Pierre Guillard , Daniel A. Evans , Robert Antonucci , P. N. Appleton , Nicole Nesvadba , Christian Leipski

A possible formation mechanism of hydrogen molecules on a galactic scale is examined. We are interested especially in the role of hydrogen molecules for formation and evolution of primordial galaxies. Then, formation process of hydrogen…

Astrophysics · Physics 2015-06-24 Hideyuki Kamaya , Hiroyuki Hirashita

We report results from a FUSE survey of interstellar molecular hydrogen (H2) in the Galactic disk toward 139 O-type and early B-type stars at Galactic latitudes $|b| < 10^{\circ}$, with updated photometric and parallax distances. The H2…

Astrophysics of Galaxies · Physics 2021-04-21 J. Michael Shull , Charles W. Danforth , Katherine L. Anderson

A detailed theory-versus-experiment comparison is worked out for H$_2^+$ intense laser dissociation, based on angularly resolved photodissociation spectra recently recorded in H.Figger's group. As opposite to other experimental setups, it…

Quantum Physics · Physics 2009-11-10 Vassili Serov , Arne Keller , Osman Atabek , Nicolas Billy

Polycyclic Aromatic Hydrocarbons (PAHs) are commonly detected in protoplanetary disks, but it is unclear what causes the wide range of intensities across the samples. In this work, the measured PAH intensities of a range of disks are…

Earth and Planetary Astrophysics · Physics 2026-02-18 Nienke van der Marel , Niels F. W. Ligterink , Ryan van der Werf , Milou Temmink , Paola Pinilla , Bin Jia , Quincy Bosschaart

Aqueous radiation chemistry emerges through ultrafast proton transfer and ion-radical formation with unexplored energy-redistribution dynamics steering the subsequent reactions. We performed time-resolved disruptive probing on pure water…

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

Lyman and Werner band absorption features from interstellar molecular hydrogen in rotational levels J = 0, 1, 2, 3 and 5 were observed in the spectrum of zeta Ori A by the Interstellar Medium Absorption Profile Spectrograph (IMAPS). Most of…

Astrophysics · Physics 2008-11-26 Edward B. Jenkins , Antonio Peimbert

Polycyclic aromatic hydrocarbon (PAH) molecules have long been suggested to be present in the interstellar medium (ISM). Nevertheless, despite their expected ubiquity and sustained searching efforts, identifying specific interstellar PAH…

Astrophysics of Galaxies · Physics 2024-03-12 Kaijun Li , Aigen Li , Xuejuan Yang , Taotao Fang

Based on theoretical spectra computed using Density Functional Theory we study the properties of Polycyclic Aromatic Hydrocarbons (PAH). In particular using bin-average spectra of PAH molecules with varying number of carbons we investigate…

Polycyclic aromatic hydrocarbons (PAHs) have been observed in O-rich planetary nebulae towards the Galactic Bulge. This combination of oxygen-rich and carbon-rich material, known as dual-dust or mixed chemistry, is not expected to be seen…

Solar and Stellar Astrophysics · Physics 2015-06-19 L. Guzman-Ramirez , E. Lagadec , D. Jones , A. A. Zijlstra , K. Gesicki

We present recent observations of small hydrocarbons (C3H2, C2H, C4H) with high abundances in the Photo-Dissociation Region of the Horsehead nebula. Our results show for the first time observational indications that the small hydrocarbon…

Astrophysics · Physics 2007-05-23 David Teyssier , David Fosse , Maryvonne Gerin , Jerome Pety , Alain Abergel , Emilie Habart

This study aims to reveal the important role and the respective rate rules of H atom abstractions by NO2 for better understanding NOX hydrocarbon interactions. To this end, H atom abstractions from C2 to C5 alkanes and alkenes 15 species by…

Chemical Physics · Physics 2024-08-28 Hongqing Wu , Ruoyue Tang , Xinrui Ren , Mingrui Wang , Guojie Liang , Haolong Li , Song Cheng

CO2 ice is one of the most abundant components in ice-coated interstellar ices besides H2O and CO, but the most favorable path to CO2 ice is still unclear. Molecular dynamics calculations on the ultraviolet photodissociation of different…

Chemical Physics · Physics 2015-06-17 Carina Arasa , Marc C. van Hemert , Ewine F. van Dishoeck , Geert-Jan Kroes

Rapid, efficient deactivation of the photoexcited PAH cations accounts for their remarkable photostability and have important implications for astrochemistry, as these cations are the leading candidates for the species responsible for the…

The PAH family of organic compounds (polycyclic aromatic hydrocarbons), involved in several fields of chemistry, has received particular attention in astrochemistry, where their vibrational spectroscopy, thermodynamic, dynamic, and…

Chemical Physics · Physics 2017-06-13 Georges Trinquier , Aude Simon , Mathias Rapacioli , Florent Xavier Gadéa

Polycyclic Aromatic Hydrocarbons (PAHs) are ubiquitous complex molecules in the interstellar medium and are used as an indirect indicator of star-formation. On the other hand the ultraviolet (UV) emission from the young massive stars…

Astrophysics of Galaxies · Physics 2024-01-09 K. Ujjwal , Sreeja S Kartha , Akhil Krishna R , Blesson Mathew , Smitha Subramanian , Sudheesh T P , Robin Thomas
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