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We have carried out interferometric observations of cyanopolyynes, HC$_{3}$N, HC$_{5}$N, and HC$_{7}$N, in the 36 GHz band toward the G28.28$-$0.36 high-mass star-forming region using the Karl G. Jansky Very Large Array (VLA) Ka-band…

Hydrogen and helium emission lines in nebulae form by radiative recombination. This is a simple process which, in principle, can be described to very high precision. Ratios of He I and H I emission lines can be used to measure the…

Astrophysics of Galaxies · Physics 2016-04-27 F. Guzmán , N. R. Badnell , R. J. R. Williams , P. A. M. van Hoof , M. Chatzikos , G. J. Ferland

The experimental determination of the reaction rate coefficients for production and destruction of $\text{HCN}^+$ and $\text{HNC}^+$ in collisions with $\text{H}_2$ is presented. A variable temperature 22 pole radio frequency ion trap was…

Astrophysics of Galaxies · Physics 2023-06-08 Petr Dohnal , Pavol Jusko , Miguel Jiménez-Redondo , Paola Caselli

An artificial neural network (ANN) is investigated as a tool for estimating rate coefficients for the collisional excitation of molecules. The performance of such a tool can be evaluated by testing it on a dataset of collisionally-induced…

Instrumentation and Methods for Astrophysics · Physics 2014-11-20 David A. Neufeld

We report the first detection in the interstellar medium of $N$-cyanomethanimine (H$_2$CNCN), the stable dimer of HCN of highest energy, and the most complex organic molecule identified in space containing the prebiotically relevant NCN…

The rate constants required to model the OH$^+$ observations in different regions of the interstellar medium have been determined using state of the art quantum methods. First, state-to-state rate constants for the H$_2(v=0,J=0,1)$+…

Solar and Stellar Astrophysics · Physics 2015-06-19 S. Gomez-Carrasco , B. Godard , F. Lique , N. Bulut , J. Klos , O. Roncero , A. Aguado , F. J. Aoiz , J. F. Castillo , J. R. Goicoechea , M. Etxaluze , J. Cernicharo

Excited atomic nitrogen atoms play an important role in plasma formation in hypersonic shock-waves, as happens during spacecraft reentry and other high velocity vehicle applications. In this study, we have thoroughly studied collision…

Chemical Physics · Physics 2024-04-24 Yanze Wu , Majdi Hochlaf , George C. Schatz

Newly-computed collisional rate coefficients for the excitation of C$_2$ in collisions with H$_2$, presented recently by Najar and Kalugina (2020), are significantly larger than the values adopted previously in models for the excitation of…

Rotational transitions in molecular hydrogen collisions are computed. The two most recently developed potential energy surfaces for the H2-H2 system are used from the following works: 1) A.I. Boothroyd, P.G. Martin, W.J. Keogh, M.J.…

Chemical Physics · Physics 2009-11-11 Renat A. Sultanov , Dennis Guster

The event of astroparticle collision at high energy was detected in 1975 during the balloon flight in the stratosphere. The data of hundred particle tracks in x-ray films have been re-analyzed in the style of LHC experiments: rapidity…

High Energy Physics - Phenomenology · Physics 2022-03-17 Olga I. Piskounova , Konstantine A. Kotelnikov

The ion-molecule reactions $\text{D}_2^++\text{NH}_3$ and $\text{D}_2^++\text{ND}_3$ are studied at low collision energies ($E_{\text{coll}}$ from zero to $\sim k_\textrm{B}\cdot 50\,\text{K}$), with the $\text{D}_2^+$ ions in the ground…

Chemical Physics · Physics 2024-03-05 Raphaël Hahn , David Schlander , Valentina Zhelyazkova , Frédéric Merkt

Isomerism in complex organic molecules provides key insights into the formation mechanisms and physical conditions of the interstellar medium (ISM). Among the C$_2$H$_5$NO isomers, only acetamide and trans-N-methylformamide (trans-NMF) have…

We present here a systematic search for cyanopolyynes in the shock region L1157-B1 and its associated protostar L1157-mm in the framework of the Large Program "Astrochemical Surveys At IRAM" (ASAI), dedicated to chemical surveys of…

A theoretical method for the estimation of cross sections and rates for excitation and charge transfer processes in low-energy hydrogen atom collisions with neutral atoms, based on an asymptotic two-electron model of ionic-covalent…

Atomic Physics · Physics 2016-05-04 Paul S. Barklem

We investigate rotational state changes in a single collision of diatomic molecular ions, polar or apolar, with an atomic ion. Rotational state changes may occur since the angular degree of freedom of the molecular ions interacts with the…

Quantum Physics · Physics 2026-04-20 J. Martin Berglund , Michael Drewsen , Christiane P. Koch

We review the new possibilities offered by the reaction dynamics of asymmetric heavy ion collisions, using stable and unstable beams. We show that it represents a rather unique tool to probe regions of highly Asymmetric Nuclear Matter…

Nuclear Theory · Physics 2009-09-29 V. Baran , M. Colonna , V. Greco , M. Di Toro

Direct collisions between finite-sized particles occur commonly in many areas of astrophysics. Such collisions are typically mediated by chaotic, bound gravitational interactions involving small numbers of particles. An important…

Astrophysics of Galaxies · Physics 2020-11-03 Carlos Barrera , Nathan W. C. Leigh , Bastián Reinoso , Amelia M. Stutz , Dominik Schleicher

New quantum scattering calculations for rotational deexcitation transitions of CO induced by H collisions using two CO-H potential energy surfaces (PESs) from Shepler et al. (2007) are reported. State-to-state rate coefficients are computed…

Solar and Stellar Astrophysics · Physics 2015-06-15 Benhui Yang , P. C. Stancil , N. Balakrishnan , R. C. Forrey , J. M. Bowman

The study of complex nitrogen (N)-bearing molecules is essential for probing the physical and chemical evolution of star-forming regions. In this paper, we present the identification of rotational emission lines from several complex…

Astrophysics of Galaxies · Physics 2026-05-27 Arijit Manna , Sabyasachi Pal , Tapas Baug , Ariful Hoque , Sandip Dutta , Sekhar Sinha , Sushanta Kumar Mondal

The amide-related molecules are essential for the formation of the other complex bio-molecules and an understanding of the prebiotic chemistry in the interstellar medium (ISM). We presented the first detection of the rotational emission…

Astrophysics of Galaxies · Physics 2023-05-10 Arijit Mannna , Sabyasachi Pal
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