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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

I explore the thermal evolution and ionization states in gas cooling from an initially hot state in the presence of external photoionizing radiation. I compute the equilibrium and nonequilibrium cooling efficiencies, heating rates, and ion…

Astrophysics of Galaxies · Physics 2017-07-05 Orly Gnat

We propose a methodology to perform a self-consistent analysis of the physical properties of the emitting gas of HII galaxies adequate to the data that can be obtained with the XXI century technology. This methodology requires the…

Astrophysics of Galaxies · Physics 2009-01-21 G. F. Hagele , A. I. Diaz , E. Terlevich , E. Perez-Montero , R. Terlevich , M. V. Cardaci

Radiative processes play a pivotal role in shaping the thermal and chemical states of gas across diverse astrophysical environments, from the interstellar medium (ISM) to the intergalactic medium. We present a hybrid cooling model for…

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 present ion-by-ion cooling efficiencies for low-density gas. We use Cloudy (ver. 08.00) to estimate the cooling efficiencies for each ion of the first 30 elements (H-Zn) individually. We present results for gas temperatures between 1e4…

Instrumentation and Methods for Astrophysics · Physics 2015-06-03 Orly Gnat , Gary J. Ferland

Gas cooling and heating rates are vital components of hydrodynamic simulations. However, they are computationally expensive to evaluate exactly with chemical networks or photoionization codes. We compare two different approximation schemes…

Astrophysics of Galaxies · Physics 2024-12-23 David Robinson , Camille Avestruz , Nickolay Y. Gnedin , Vadim A. Semenov

Radiative cooling is an important ingredient in hydrodynamical models involving evolution of high temperature plasmas. Unfortunately, calculating an accurate cooling coefficient generally requires the solution of over a hundred differential…

Astrophysics · Physics 2009-11-06 Robert A. Benjamin , Bradford A. Benson , Donald P. Cox

The hydrogen plasma is studied at temperatures T ~ 10^4 - 10^6 K using the free energy minimization method. A simple analytic free energy model is proposed which is accurate at densities up to 1 g/cc and yields convergent internal partition…

plasm-ph · Physics 2009-10-30 A. Y. Potekhin

The energy transfer among the components in a gas determines its fate. Especially at low temperatures, inelastic collisions drive the cooling and the heating mechanisms. In the early Universe as well as in zero- or low- metallicity…

Astrophysics of Galaxies · Physics 2019-07-04 Carla Maria Coppola , François Lique , Francesca Mazzia , Fabrizio Esposito , Mher V. Kazandjian

Nonequilibrium (time-dependent) cooling rates and ionization state calculations are presented for low-density gas enriched with heavy elements (metals) and photoionized by external ultraviolet/X-ray radiation. We consider a wide range of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Evgenii O. Vasiliev

This work presents a new plasma cooling curve that is calculated using the SPEX package. We compare our cooling rates to those in previous works, and implement the new cooling function in the grid-adaptive framework `AMRVAC'. Contributions…

Astrophysics of Galaxies · Physics 2009-11-26 K. M. Schure , D. Kosenko , J. S. Kaastra , R. Keppens , J. Vink

We present first results of the evolution of cold cosmic gas obtained through a set of state-of-the-art numerical simulations (ColdSIM). We model time-dependent atomic and molecular non-equilibrium chemistry coupled to HI and H$_2$…

Astrophysics of Galaxies · Physics 2022-02-09 U. Maio

We use the spectral synthesis code Cloudy to tabulate the properties of gas for an extensive range in redshift (z=0 to 9), temperature (log T [K] = 1 to 9.5), metallicity (log Z/$\mathrm{Z}_{\odot}$ = -4 to +0.5, Z=0), and density (log…

Astrophysics of Galaxies · Physics 2020-08-05 Sylvia Ploeckinger , Joop Schaye

We present an efficient heating/cooling method coupled with chemistry and ultraviolet (UV) radiative transfer, which can be applied to numerical simulations of the interstellar medium (ISM). We follow the time-dependent evolution of…

Astrophysics of Galaxies · Physics 2022-12-28 Jeong-Gyu Kim , Munan Gong , Chang-Goo Kim , Eve C. Ostriker

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

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

Aims: We aim to simulate radial profiles of molecular abundances and the gas temperature in cold and heavily shielded starless cores by combining chemical and radiative transfer models. Methods: A determination of the dust temperature in a…

Astrophysics of Galaxies · Physics 2015-06-05 O. Sipilä

Context. The radiative energy balance in the solar chromosphere is dominated by strong spectral lines that are formed out of LTE. It is computationally prohibitive to solve the full equations of radiative transfer and statistical…

Solar and Stellar Astrophysics · Physics 2015-06-04 Mats Carlsson , Jorrit Leenaarts

(Abridged) To define a framework for the formation and evolution of the cooling cores in X-ray galaxy clusters, we study how the physical properties change as function of the cosmic time in the inner regions of a 4 keV and 8 keV galaxy…

Astrophysics · Physics 2009-11-13 Stefano Ettori , Fabrizio Brighenti
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