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Related papers: Chemical Rates on Small Grains and PAHs: C^+ Recom…

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We explore the physical origins of the observed deficit of polycyclic aromatic hydrocarbons (PAHs) at sub-solar metallicity using JWST/NIRCam imaging of the nearby galaxy M101, covering regions from solar metallicity (Z$_{\odot}$) down to…

New insights into the formation of interstellar formamide, a species of great relevance in prebiotic chemistry, are provided by electronic structure and kinetic calculations for the reaction NH2 + H2CO -> NH2CHO + H. Contrarily to what…

Astrophysics of Galaxies · Physics 2015-08-19 V. Barone , C. Latouche , D. Skouteris , F. Vazart , N. Balucani , C. Ceccarelli , B. Lefloch

We present experimental data on H2 formation processes on gas-phase polycyclic aromatic hydrocarbon (PAH) cations. This process was studied by exposing coronene radical cations, confined in a radio-frequency ion trap, to gas phase H atoms.…

Astrophysics of Galaxies · Physics 2018-09-05 N. Foley , S. Cazaux , D. Egorov , L. M. P. V. Boschman , R. Hoekstra , T. Schlatholter

Our automated reaction discovery program, AutoMeKin, has been utilized to investigate the formation of glycolonitrile (HOCH$_{2}$CN) in the gas phase under the low temperatures of the interstellar medium (ISM). The feasibility of a proposed…

The feasibility of contemporary gas-grain astrochemical models depends on the availability of accurate kinetics data, in particular, for surface processes. We study the sensitivity of gas-grain chemical models to the energy barrier Ea of…

Astrophysics of Galaxies · Physics 2020-05-20 Matjaž Simončič , Dmitry Semenov , Serge Krasnokutski , Thomas Henning , Cornelia Jäger

The internal energy available in vibrationally excited H2 molecules can be used to overcome or diminish the activation barrier of various chemical reactions of interest for molecular astrophysics. In this article we investigate in detail…

Astrophysics of Galaxies · Physics 2015-05-18 M. Agundez , J. R. Goicoechea , J. Cernicharo , A. Faure , E. Roueff

Protoplanetary disks are the target of many chemical studies (both observational and theoretical) as they contain the building material for planets. Their large vertical and radial gradients in density and temperature make them challenging…

Astrophysics of Galaxies · Physics 2016-10-07 V. Wakelam , M. Ruaud , F. Hersant , A. Dutrey , D. Semenov , L. Majumdar , S. Guilloteau

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…

The reaction between atomic oxygen and molecular hydrogen is an important one in astrochemistry as it regulates the abundance of the hydroxyl radical and serves to open the chemistry of oxygen in diverse astronomical environments. However,…

Astrophysics of Galaxies · Physics 2021-04-21 A. Veselinova , M. Agundez , J. R. Goicoechea , M. Menendez , A. Zanchet , E. Verdasco , P. G. Jambrina , F. J. Aoiz

Star formation activity in molecular clouds is often found to be correlated with the amount of material above a column density threshold of $\sim 10^{22} \, {\rm cm^{-2}}$. Attempts to connect this column density threshold to a ${\it…

Astrophysics of Galaxies · Physics 2023-10-11 F. D. Priestley , P. C. Clark , S. C. O. Glover , S. E. Ragan , O. Fehér , L. R. Prole , R. S. Klessen

We have obtained CO(1-0) observations for a sample of 37 interacting galaxy systems, chosen from a parent sample of optically-selected interacting galaxies. The sample observed here spans a large range of interaction strengths and star…

Astrophysics · Physics 2007-05-23 Howard A. Bushouse , Steven D. Lord , Susan A. Lamb , Michael W. Werner , K. Y. Lo

Polycyclic aromatic hydrocarbons (PAHs) are a ubiquitous component of the interstellar medium (ISM) in z~0 massive, star-forming galaxies and play key roles in ISM energy balance, chemistry, and shielding. Wide field of view, high…

We present analytic theory for the total column density of singly ionized carbon (C+) in the optically thick photon dominated regions (PDRs) of far-UV irradiated (star-forming) molecular clouds. We derive a simple formula for the C+ column…

Astrophysics of Galaxies · Physics 2016-08-31 Raanan Nordon , Amiel Sternberg

Previous work by various authors has suggested that the detection by Herschel/HIFI of nitrogen hydrides along the low density lines of sight towards G10.6-0.4 (W31C) cannot be accounted for by gas-phase chemical models. In this paper we…

Astrophysics of Galaxies · Physics 2017-03-16 Zainab Awad , Serena Viti , David A. Williams

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…

The $\mathrm{H}_2$ formation on grains is known to be sensitive to dust temperature, which is also known to fluctuate for small grain sizes due to photon absorption. We aim at exploring the consequences of simultaneous fluctuations of the…

Astrophysics of Galaxies · Physics 2014-10-01 Emeric Bron , Jacques Le Bourlot , Franck Le Petit

Carbonaceous grains represent a major component of cosmic dust. In order to understand their formation pathways, they have been prepared in the laboratory by gas-phase condensation reactions such as laser pyrolysis and laser ablation. Our…

Astrophysics of Galaxies · Physics 2011-02-11 C. Jäger , H. Mutschke , I. Llamas Jansa , Th. Henning , F. Huisken

The formation of CO2 in quiescent regions of molecular clouds is not yet fully understood, despite CO2 having an abundance of around 10-34 % H2O. We present a study of the formation of CO2 via the non-energetic route CO + OH on non-porous…

Solar and Stellar Astrophysics · Physics 2011-07-05 Jennifer Anna Noble , François Dulieu , Emanuele Congiu , Helen Jane Fraser

The rate constants for the formation, destruction, and collisional excitation of SH$^+$ are calculated from quantum mechanical approaches using two new SH$_2^+$ potential energy surfaces (PESs) of $^4A''$ and $^2A''$ electronic symmetry.…

Astrophysics of Galaxies · Physics 2019-06-26 Alexandre Zanchet , Francois Lique , Octavio Roncero , Javier R. Goicoechea , Niyazi Bulut

The first hydrostatic core (FHSC) phase is a brief stage in the protostellar evolution that is difficult to detect. Our goal is to characterize the chemical evolution of gas and dust during the formation of the FHSC. Moreover, we are…