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Related papers: CF$^+$ excitation in the interstellar medium

200 papers

We examine observational characteristics of multi-phase turbulent flows in the diffuse interstellar medium (ISM) using a synthetic radiation field of atomic and molecular lines. We consider the multi-phase ISM which is formed by thermal…

Astrophysics · Physics 2008-11-26 M. Yamada , H. Koyama , K. Omukai , S. Inutsuka

C+ is a key species in the interstellar medium but its 158 {\mu}m fine structure line cannot be observed from ground-based telescopes. Current models of fluorine chemistry predict that CF+ is the second most important fluorine reservoir, in…

Astrophysics of Galaxies · Physics 2015-06-05 V. Guzmán , J. Pety , P. Gratier , J. R. Goicoechea , M. Gerin , E. Roueff , D. Teyssier

We investigate the non-Local Thermodynamic Equilibrium (non-LTE) line formation of neutral carbon in late-type stars in order to remove some of the potential systematic errors in stellar abundance analyses employing C I features. The…

Astrophysics · Physics 2009-11-11 D. Fabbian , M. Asplund , M. Carlsson , D. Kiselman

Two different ab initio potential energy surfaces are employed to investigate the efficiency of the rotational excitation channels for the polar molecular ion HeH$^+$ interacting with He atoms. We further use them to investigate the quantum…

We present state-selected measurements of rotational cooling and excitation rates of CH$^+$ molecular ions by inelastic electron collisions. The experiments are carried out at the Cryogenic Storage Ring, making use of a monoenergetic…

An accurate treatment of the multiphase interstellar medium (ISM) in hydrodynamic galaxy simulations requires that we follow not only the thermal evolution of the gas, but also the evolution of its chemical state, including its molecular…

Astrophysics of Galaxies · Physics 2015-06-18 Alexander J. Richings , Joop Schaye , Benjamin D. Oppenheimer

We report the first detection of the J = 1 - 0 (102.6 GHz) rotational lines of CF+ (fluoromethylidynium ion) towards CygX-N63, a young and massive protostar of the Cygnus X region. This detection occurred as part of an unbiased spectral…

Solar and Stellar Astrophysics · Physics 2015-01-23 S. Fechtenbaum , S. Bontemps , N. Schneider , T. Csengeri , A. Duarte-Cabral , F. Herpin , B. Lefloch

The first set of theoretical cross sections for propylene oxide (CH3CHCH2O) colliding with cold He atoms has been obtained at the full quantum level using a high-accuracy potential energy surface. By scaling the collision reduced mass,…

Astrophysics of Galaxies · Physics 2022-02-16 K. Dzenis , A. Faure , B. A. McGuire , A. J. Remijan , P. J. Dagdigian , C. Rist , R. Dawes , E. Quintas-Sanchez , F. Lique , M. Hochlaf

Europium plays a key role in studies of nucleosynthesis in the rapid (r-) process of neutron capture nuclear reactions and the evolution of the r-process element abundances in galaxies. We refine the method for analyzing the Eu~II lines in…

Solar and Stellar Astrophysics · Physics 2026-04-27 L. I. Mashonkina , S. A. Yakovleva

The excitation temperature T_01 derived from the relative intensities of the J = 0 (para) and J = 1 (ortho) rotational levels of H2 has been assumed to be an accurate measure of the kinetic temperature in interstellar environments. In…

Astrophysics of Galaxies · Physics 2015-05-27 Kyle N. Crabtree , Nick Indriolo , Holger Kreckel , Brian A. Tom , Benjamin J. McCall

The intermittent dissipation of interstellar turbulence is an important energy source in the diffuse ISM. Though on average smaller than the heating rates due to cosmic rays and the photoelectric effect on dust grains, the turbulent cascade…

Astrophysics of Galaxies · Physics 2015-09-11 Andrew Myers , Christopher McKee , Pak Shing Li

The TIRAMISU code, a new program for computing on-the-fly non-LTE molecular spectra and opacities for solving self-consistent radiative transfer problems in exoplanet atmospheres, is presented. The ultra-hot Jupiter KELT-20 b is used as a…

Earth and Planetary Astrophysics · Physics 2025-08-19 Charles A. Bowesman , Sergei N. Yurchenko , Ahmed Al-Refaie , Jonathan Tennyson

The interpretation of observed spectra of stars in terms of fundamental stellar properties is a key problem in astrophysics. For FGK-type stars, the radiative transfer models are often computed using the assumption of local thermodynamic…

Solar and Stellar Astrophysics · Physics 2023-06-14 Maria Bergemann , Thomas Nordlander

$Aims$: We revisit with new augmented accuracy the theoretical dynamics of basic isotope exchange reactions involved in the $^{12}$C/$^{13}$C, $^{16}$O/$^{18}$O, and $^{14}$N/$^{15}$N balance because these reactions have already been…

Astrophysics of Galaxies · Physics 2015-06-19 Mirjana Mladenović , Evelyne Roueff

The time-dependent rate coefficients for the charge exchange reaction C+ + Si -> C + Si+ for doublet and quartet states have been determined with ab initio quantum calculations coupled with a non-adiabatic transition model based on a simple…

Astrophysics of Galaxies · Physics 2015-06-11 M. Satta , T. Grassi , F. A. Gianturco

The abundances of carbon, oxygen, and iron in late-type stars are important parameters in exoplanetary and stellar physics, as well as key tracers of stellar populations and Galactic chemical evolution. We carried out three-dimensional (3D)…

Solar and Stellar Astrophysics · Physics 2019-10-09 A. M. Amarsi , P. E. Nissen , Á. Skúladóttir

We present three-dimensional astrochemical simulations and synthetic observations of magnetised, turbulent, self-gravitating molecular clouds. We explore various galactic interstellar medium environments, including cosmic-ray ionization…

Astrophysics of Galaxies · Physics 2021-01-20 Thomas G. Bisbas , Jonathan C. Tan , Kei E. I. Tanaka

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…

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

Spectroscopic measurements of iron abundances are prone to systematic modelling errors. We present 3D non-LTE calculations across 32 STAGGER-grid models with effective temperatures from 5000 K to 6500 K, surface gravities of 4.0 dex and 4.5…

Solar and Stellar Astrophysics · Physics 2022-12-12 A. M. Amarsi , S. Liljegren , P. E. Nissen