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Related papers: Dynamic Hydrogen Ionization

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The first, self-consistent calculations are presented of the cosmological, H2-dissociating UV background produced during the epoch of reionization by the sources of reionization. Large-scale radiative transfer simulations of reionization…

Astrophysics · Physics 2015-05-13 Kyungjin Ahn , Paul R. Shapiro , Ilian T. Iliev , Garrelt Mellema , Ue-Li Pen

We study the impact of inhomogeneous hydrogen reionization on the thermal evolution of the intergalactic medium (IGM) using hydrodynamic + radiative transfer simulations where reionization is completed either early (z ~ 9) or late (z ~ 6).…

Astrophysics · Physics 2009-11-13 Hy Trac , Renyue Cen , Abraham Loeb

The critical star formation rate density required to keep the intergalactic hydrogen ionised depends crucially on the average rate of recombinations in the intergalactic medium (IGM). This rate is proportional to the clumping factor C =…

Astrophysics · Physics 2009-09-03 Andreas H. Pawlik , Joop Schaye , Eveline van Scherpenzeel

The energy for the coronal heating must be provided from the convection zone. The amount and the method by which this energy is transferred into the corona depends on the properties of the lower atmosphere and the corona itself. We review:…

Solar and Stellar Astrophysics · Physics 2023-07-19 Juan Martinez-Sykora , Bart De Pontieu , Viggo H. Hansteen , Mats Carlsson

We have reanalyzed SUMER observations of a parcel of coronal gas using new collisional ionization equilibrium (CIE) calculations. These improved CIE fractional abundances were calculated using state-of-the-art electron-ion recombination…

Astrophysics · Physics 2011-02-11 P. Bryans , E. Landi , D. W. Savin

We present a model for the rate of temperature relaxation between electrons and ions in plasmas. The model includes self-consistently the effects of particle screening, electron degeneracy and correlations between electrons and ions. We…

Plasma Physics · Physics 2015-05-13 Jérôme Daligault , Guy Dimonte

Models and simulations of the epoch of reionization predict that spectra of the 21-cm transition of atomic hydrogen will show a clear fluctuation peak, at a redshift and scale, respectively, that mark the central stage of reionization and…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Anastasia Fialkov , Rennan Barkana , Eli Visbal

We present extensive molecular dynamics (MD) simulations investigating numerous candidate crystal structures for hydrogen in conditions around the present experimental frontier (400GPa). Spontaneous phase transitions in the simulations…

Materials Science · Physics 2015-11-18 Ioan B. Magdau , Graeme J. Ackland

The temporal evolution of the ionizing UV background radiation field at high redshift provides a probe of the evolution of the early star formation rate. By comparing the observed levels of absorption in the highest redshift quasar spectra…

Astrophysics · Physics 2009-11-07 Renyue Cen , Patrick McDonald

The sun's chromosphere is a highly dynamic, partially-ionized region where spicules (hot jets of plasma) form. Here we present a two-fluid MHD model to study the chromosphere, which includes ion-neutral interaction and frictional heating.…

Solar and Stellar Astrophysics · Physics 2019-10-02 Qusai Al Shidi , Ofer Cohen , Paul Song , Jiannan Tu

We initiate a holographic study of coupling-dependent heavy ion collisions by analysing for the first time the effects of leading-order, inverse coupling constant corrections. In the dual description, this amounts to colliding gravitational…

High Energy Physics - Theory · Physics 2017-07-20 Sašo Grozdanov , Wilke van der Schee

The recent low value of Planck (2016) integrated optical depth to Thomson scattering suggests that the reionization occurred fairly suddenly, disfavoring extended reionization scenarios. This will have a significant impact on the 21cm power…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-27 Sultan Hassan , Romeel Dave , Kristian Finlator , Mario G. Santos

We investigate a non-equilibrium ionization state and an electron-ion two-temperature structure of the intracluster medium (ICM) in merging galaxy clusters using a series of N-body and hydrodynamic simulations. Mergers with various sets of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Takuya Akahori , Kohji Yoshikawa

The distribution of temperature and emission measure in the stationary heated solar atmosphere was obtained for the limiting cases of slow and fast heating, when either the gas pressure or the concentration are constant throughout the layer…

Solar and Stellar Astrophysics · Physics 2010-04-16 O. Ptitsyna , B. Somov

We study the acceleration of heavy nuclei at SNR shocks taking into account the process of ionization. In the interstellar medium atoms heavier then hydrogen which start the diffusive shock acceleration (DSA) are never fully ionized at the…

High Energy Astrophysical Phenomena · Physics 2015-05-20 Giovanni Morlino

Investigating the reliability of the assumption of instantaneous chemical equilibrium (ICE) for calculating the CO number density in the solar atmosphere is of crucial importance for the resolution of the long-standing controversy over the…

Astrophysics · Physics 2009-11-07 A. Asensio Ramos , J. Trujillo Bueno , M. Carlsson , J. Cernicharo

The conditions within the ionization front of a quasar during reionization (T ~ 30,000 K, neutral hydrogen fraction ~ 0.5) are ideal for producing Lyman-alpha emission via collisional excitation of hydrogen atoms. Observations of this…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-15 Frederick B. Davies , Steven R. Furlanetto , Matthew McQuinn

The estimate of the ionizing UV background through the proximity effect analysis is discussed. Taking into account the correct bending of the column density distribution which appears in high resolution high s/n data, a value of the UV…

Astrophysics · Physics 2007-05-23 E. Giallongo , S. Cristiani , S. D'Odorico , A. Fontana , S. Savaglio

By depleting the ionizing photon budget available to expand cosmic HII regions, recombining systems (or Lyman limit systems) can have a large impact during (and following) cosmic reionization. Unfortunately, directly resolving such…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Emanuele Sobacchi , Andrei Mesinger

The neutral hydrogen (HI) and its 21 cm line are promising probes to the reionization process of the intergalactic medium (IGM). To use this probe effectively, it is imperative to have a good understanding on how the neutral hydrogen traces…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-06 Wenxiao Xu , Yidong Xu , Bin Yue , Ilian T Iliev , Hy Trac , Liang Gao , Xuelei Chen
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