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Related papers: Modeling molecular hyperfine line emission

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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

A line list of vibration-rotation transitions for 13C substituted HCN is presented. The line list is constructed using known experimental levels where available, calculated levels and ab initio line intensities originally calculated for the…

Astrophysics · Physics 2009-11-13 G. J. Harris , F. C. Larner , J. Tennyson , B. M. Kaminsky , Ya. V. Pavlenko , H. R. A. Jones

In this paper, a linear model based on multiple measurement vectors model is proposed to formulate the inverse scattering problem of highly conductive objects at one single frequency. Considering the induced currents which are mostly…

Signal Processing · Electrical Eng. & Systems 2019-06-27 Shilong Sun , Bert Jan Kooij , Alexander G. Yarovoy

The large quantity and high quality of modern radio and infrared line observations require efficient modeling techniques to infer physical and chemical parameters such as temperature, density, and molecular abundances. We present a computer…

Theoretical calculations are contributing a significantly higher proportion of data to contemporary spectroscopic databases, which have traditionally relied on experimental observations and semi-empirical models. It is now a common…

A theoretical model of the influence of detection bandwidth properties on observed line shapes in laser absorption spectroscopy is described. The model predicts artificial frequency shifts, extra broadenings and line asymmetries which must…

High-precision stellar analyses require hydrodynamic 3D modeling. Such models predict changes across stellar disks of spectral line shapes, asymmetries, and wavelength shifts. For testing models in stars other than the Sun, spatially…

Solar and Stellar Astrophysics · Physics 2021-04-28 Dainis Dravins , Hans-Günter Ludwig , Bernd Freytag

Heavy-ion collision physics has entered the high precision era, demanding theoretical models capable of generating huge statistics to compare with experimental data. However, traditional hybrid models, which combine hydrodynamics and…

Nuclear Theory · Physics 2025-10-28 Jing-An Sun , Li Yan , Charles Gale , Sangyong Jeon

We present a simple quantum mechanical model describing excited rotational states of molecules in superfluid helium nanodroplets, as recently studied in non-adiabatic molecular alignment experiments [Cherepanov et al., Phys. Rev. A 104,…

In the first section we present the atomic part where a C2+ atomic target was prepared and used to generate theoretical data to investigate recombination lines arising from electron-ion collisions in thin plasma. R-matrix method was used to…

Atomic Physics · Physics 2012-11-07 Taha Sochi

Spectral unmixing is a crucial processing step when analyzing hyperspectral data. In such analysis, most of the work in the literature relies on the widely acknowledged linear mixing model to describe the observed pixels. Unfortunately,…

Data Analysis, Statistics and Probability · Physics 2014-04-21 Nicolas Dobigeon , Laurent Tits , Ben Somers , Yoann Altmann , Pol Coppin

We investigate the orientation dependence of high-order harmonic generation (HHG) from H$_2^+$ with different internuclear distances irradiated by intense laser fields both numerically and analytically. The calculated molecular HHG spectra…

Atomic Physics · Physics 2009-11-13 Yanjun Chen , Jie Liu , Bambi Hu

Streamer discharges pose basic problems in plasma physics, as they are very transient, far from equilibrium and have high ionization density gradients; they appear in diverse areas of science and technology. The present paper focuses on the…

Plasma Physics · Physics 2013-11-13 S. Dujko , A. H. Markosyan , R. D. White , U. Ebert

Rate coefficients for inelastic Mg+H collisions are calculated for all transitions between the lowest seven levels and the ionic state (charge transfer). The rate coefficients are based on cross-sections from full quantum scattering…

Solar and Stellar Astrophysics · Physics 2015-06-04 P. S. Barklem , A. K. Belyaev , A. Spielfiedel , M. Guitou , N. Feautrier

Here we present our current updates of the gas-phase chemical reaction rates and molecular lines in the spectral synthesis code CLOUDY, and its implications in spectroscopic modelling of various astrophysical environments. We include energy…

Astrophysics of Galaxies · Physics 2022-08-03 Gargi Shaw , G. J. Ferland , M. Chatzikos

Motivated by the observed differences in the nebular emission of nearby and high-redshift galaxies, we carry out a set of direct numerical simulations of turbulent astrophysical media exposed to a UV background. The simulations assume a…

Astrophysics of Galaxies · Physics 2017-11-15 William J. Gray , Evan Scannapieco

Molecular line data for the rotational transitions of a number of astrophysically interesting species have been collected and are made publically available through the www. These data, including energy levels, statistical weights, Einstein…

Astrophysics · Physics 2007-05-23 F. L. Schoeier , F. F. S. van der Tak , E. F. van Dishoeck , J. H. Black

A theory is developed for the evolution of the non-equilibrium distribution of quasiparticles when the scattering rate decreases due to particle collisions. We propose a "modified one-collision approximation" which is most effective for…

Disordered Systems and Neural Networks · Physics 2009-11-10 R. N. Gurzhi , A. I. Kopeliovich , A. N. Kalinenko , A. V. Yanovsky , E. N. Bogachek , Uzi Landman , H. Buhmann , L. W. Molenkamp

Far-infrared molecular emission is an important tool used to understand the excitation mechanisms of the gas in the inter-stellar medium of star-forming galaxies. In the present work, we model the emission from rotational transitions with…

Astrophysics of Galaxies · Physics 2016-11-23 M. V. Kazandjian , I. Pelupessy , R. Meijerink , F. P. Israel , C. M. Coppola , M. J. F. Rosenberg , M. Spaans

Recent research has proven neural networks to be a powerful tool for performing hyperspectral imaging (HSI) target identification. However, many deep learning frameworks deliver a single material class prediction and operate on a per-pixel…

Machine Learning · Computer Science 2025-08-14 Joshua R. Tempelman , Kevin Mitchell , Adam J. Wachtor , Eric B. Flynn
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