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At low temperatures, the main coolant in primordial gas is molecular hydrogen, H2. Recent work has shown that primordial gas that is not collapsing gravitationally but is cooling from an initially ionized state forms hydrogen deuteride, HD,…

Astrophysics · Physics 2009-11-13 S. C. O. Glover , T. Abel

We report new calculations of the cooling rate of primordial gas by the HD molecule, taking into account its ro-vibrational structure. The HD cooling function is calculated including radiative and collisional transitions for J\le8…

Astrophysics · Physics 2009-11-10 A. Lipovka , R. Nunez-Lopez , V. Avila-Reese

Experimental measurements and theoretical calculations of state-to-state rate coefficients for rotational energy transfer of CO in collision with H$_2$ are reported at the very low temperatures prevailing in dense interstellar clouds (5 -…

This work follows Lykins et al. discussion of classic plasma cooling function at low density and solar metallicity. Here we focus on how the cooling function changes over a wide range of density (n_H<10^12 cm^(-3)) and metallicity (Z<30Z…

Instrumentation and Methods for Astrophysics · Physics 2014-05-12 Ye Wang , G. J. Ferland , M. L. Lykins , R. L. Porter , P. A. M. van Hoof , R. J. R. Williams

Cooling is the main process leading to the condensation of gas in the dark matter potential wells and consequently to star and structure formation. In a metal-free environment, the main available coolants are H, He, H$_2$ and HD; once the…

Astrophysics · Physics 2009-11-13 U. Maio , K. Dolag , B. Ciardi , L. Tornatore

Cooling and heating functions of cosmic gas are a crucial ingredient for any study of gas dynamics and thermodynamics in the interstellar and intergalactic medium. As such, they have been studied extensively in the past under the assumption…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Nickolay Y. Gnedin , Nicholas Hollon

In this paper, we present a new calculation of composition-dependent radiative cooling and heating curves of low-density gas, intended primarily for use in numerical simulations of galaxy formation and evolution. These curves depend on only…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Sven De Rijcke , Joeri Schroyen , Bert Vandenbroucke , Natalie Jachowicz , Jeroen Decroos , Annelies Cloet-Osselaer , Mina Koleva

We develop a numerical method to study the dynamics of a two-component atomic Fermi gas trapped inside a harmonic potential at temperature T well below the Fermi temperature Tf. We examine the transition from the collisionless to the…

Statistical Mechanics · Physics 2009-11-07 F. Toschi , P. Vignolo , S. Succi , M. P. Tosi

OH is a cornerstone molecule in the chemistry of interstellar and circumstellar media and is ubiquitously detected in warm gas thanks to its infrared rotational lines. However, the excitation processes of OH remain poorly characterized. We…

The inhomogeneous cooling state describing the hydrodynamic behavior of a freely evolving granular gas strongly confined between two parallel plates is studied, using a Boltzmann kinetic equation derived recently. By extending the idea of…

Statistical Mechanics · Physics 2019-12-20 J. Javier Brey , M. I. García de Soria , P. Maynar

We investigated the cooling mechanism due to H2 and HD molecules in order to determine the minimum temperature achievable by cold H2-HD clouds in cooling flow clusters.

Astrophysics · Physics 2007-05-23 L. Grenacher , Ph. Jetzer , D. Puy

We use a non-equilibrium chemical network to revisit and study the effect of H_{2}, HD and LiH molecular cooling on a primordial element of gas. We solve both the thermal and chemical equations for a gas element with an initial temperature…

Astrophysics · Physics 2009-02-13 Joaquin P. Prieto , Leopoldo Infante , Raul Jimenez

We present self-consistent calculations of non-equilibrium (time-dependent) cooling rates for a dust-free collisionally controlled gas in wide temperature ($10 K\le T\le 10^8 K$) and metallicity ($10^{-4} Z_\odot \le Z \le 2 Z_\odot$)…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Evgenii O. Vasiliev

The collision cross sections (CCS), momentum transfer cross sections (MTCS), or scattering cross sections (SCS) of an electron neutral pair are important components for computing the electric conductivity of a plasma gas. Larger collision…

Plasma Physics · Physics 2023-10-18 Osama A. Marzouk

Using density-functional molecular dynamics simulations we analyzed the cooling-rate effects on the physical properties of GeS$_2$ chalcogenide glasses. Liquid samples were cooled linearly in time according to $T(t) = T_0 - \gamma t$ where…

Disordered Systems and Neural Networks · Physics 2007-05-23 Sebastien Le Roux , Philippe Jund

The low-temperature (up to about 100K) collisional (de)excitation cross sections are computed using the full coupled-channel (CC) quantum dynamics for both Li$_2$ and Li$_2^+$ molecular targets in collision with $^4$He. The interaction…

Chemical Physics · Physics 2007-07-13 M. Wernli. E. Bodo , F. A. Gianturco

A close coupling quantum-mechanical calculation is performed for rotational energy transfer in a HD+HD collision at very low energy, down to the ultracold temperatures: $T \sim 10^{-8}$ K. A global six-dimensional H$_2$-H$_2$ potential…

Chemical Physics · Physics 2015-06-03 Renat A. Sultanov , Dennis Guster , S. K. Adhikari

Rate coefficients for rotational transitions in H_2 induced by H_2 impact are presented. Extensive quantum mechanical coupled-channel calculations based on a recently published (H_2)_2 potential energy surface were performed. The potential…

We present new computations of the equilibrium and non-equilibrium cooling efficiencies and ionization states for low-density radiatively cooling gas containing cosmic abundances of the elements H, He, C, N, O, Ne, Mg, Si, S, and Fe. We…

Astrophysics · Physics 2009-11-11 Orly Gnat , Amiel Sternberg

The radiative cooling of shocked gas with primordial chemical composition is an important process relevant to the formation of the first stars and structures, as well as taking place also in high velocity cloud collisions and supernovae…

Astrophysics of Galaxies · Physics 2016-03-16 C. M. Coppola , G. Mizzi , D. Bruno , F. Esposito , D. Galli , F. Palla , S. Longo
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