English
Related papers

Related papers: Fully-Coupled Simulation of Cosmic Reionization. I…

200 papers

This paper presents a new code for performing multidimensional radiation hydrodynamic (RHD) simulations on parallel computers involving anisotropic radiation fields and nonequilibrium effects. The radiation evolution modules described here…

Astrophysics · Physics 2009-11-07 John C. Hayes , Michael L. Norman

We investigate the reconstruction of a turbulent flow field in the atmospheric boundary layer from a time series of lidar measurements, using Large-Eddy Simulations (LES) and a 4D-Var data assimilation algorithm. This leads to an…

Fluid Dynamics · Physics 2020-11-17 Pieter Bauweraerts , Johan Meyers

High-power femtosecond laser radiation during the propagation in air (and other transparent media) experiences multiple filamentation. Filamentation is a unique nonlinear optical phenomenon, which is accompanied by a wealth of nonlinear…

Optics · Physics 2023-06-29 Andrey Bulygin , Yury Geints

Developing efficient path integral (PI) methods for atomistic simulations of vibrational spectra in heterogeneous condensed phases and interfaces has long been a challenging task. Here, we present the h-CMD method, short for hybrid centroid…

Chemical Physics · Physics 2025-05-08 Dil K. Limbu , Nathan London , Md Omar Faruque , Mohammad R. Momeni

We present a method for customizing the root grid of zoom-in initial conditions used for simulations of galaxy formation. Starting from the white noise used to seed the structures of an existing initial condition, we cut out a smaller…

Astrophysics of Galaxies · Physics 2020-09-22 Gillen Brown , Oleg Y. Gnedin

We explore scenarios for reionizing the intergalactic medium with low galaxy ionizing photon escape fractions. We combine simulation-based halo-mass dependent escape fractions with an extrapolation of the observed galaxy rest-ultraviolet…

An efficient numerical algorithm for the laser driven multi-level ionization of high-atomic-number gases is proposed and implemented in an electromagnetic particle-in-cell code SPACE. The algorithm is based on analytical solutions to the…

Plasma Physics · Physics 2022-02-23 Aiqi Cheng , Roman Samulyak

In an attempt to investigate the structures of ultra-relativistic jets injected into the intracluster medium (ICM) and the associated flow dynamics, such as shocks, velocity shear, and turbulence, we have developed a new special…

High Energy Astrophysical Phenomena · Physics 2021-11-03 Jeongbhin Seo , Hyesung Kang , Dongsu Ryu , Seungwoo Ha , Indranil Chattopadhyay

Lyman limit systems (LLSs) are dense hydrogen clouds with high enough HI column densities to absorb Lyman continuum photons emitted from distant quasars. Their high column densities imply an origin in dense environments; however, the…

Astrophysics of Galaxies · Physics 2024-03-04 Jiawen Fan , Hanjue Zhu , Camille Avestruz , Nickolay Y. Gnedin

We study the reionisation of the Universe by stellar sources using a numerical approach that combines fast 3D radiative transfer calculations with high resolution hydrodynamical simulations. Ionising fluxes for the sources are derived from…

Astrophysics · Physics 2009-11-07 Aaron Sokasian , Tom Abel , Lars Hernquist , Volker Springel

Multi-level non-local thermodynamic equilibrium (NLTE) radiation transfer calculations have become standard throughout the stellar atmospheres community and are applied to all types of stars as well as dynamical systems such as novae and…

Solar and Stellar Astrophysics · Physics 2014-07-02 Peter H. Hauschildt , E. Baron

In order to better understand the relationship between feedback and galactic chemical evolution, we have developed a new model for stellar feedback at grid resolutions of only a few parsecs in global disk simulations, using the adaptive…

Astrophysics of Galaxies · Physics 2018-10-17 Andrew Emerick , Greg L. Bryan , Mordecai-Mark Mac Low

This paper describes the main features of a pioneering unsteady solver for simulating ideal two-fluid plasmas on unstructured grids, taking profit of GPGPU (General-purpose computing on graphics processing units). The code, which has been…

A finite element method for solving the resonance line transfer problem in moving media is presented. The algorithm works in three spatial dimensions on unstructured grids which are adaptively refined by means of an a posteriori error…

Astrophysics · Physics 2009-11-07 E. Meinkoehn , S. Richling

The paper describes an explicit multi-dimensional numerical scheme for Special Relativistic Two-Fluid Magnetohydrodynamics of electron-positron plasma and a suit of test problems. The scheme utilizes Cartesian grid and the third order WENO…

High Energy Astrophysical Phenomena · Physics 2015-06-17 Maxim Barkov , Serguei S. Komissarov , Vitaly Korolev , Andrey Zankovich

We introduce the cosmological HYPER code based on an innovative hydro-particle-mesh (HPM) algorithm for efficient and rapid simulations of gas and dark matter. For the HPM algorithm, we update the approach of Gnedin & Hui (1998) to expand…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-09 Yizhou He , Hy Trac , Nickolay Y. Gnedin

We develop a computational method for modeling electrostatic interactions of arbitrarily-shaped, polarizable objects on colloidal length scales, including colloids/nanoparticles, polymers, and surfactants, dispersed in explicit ion…

Soft Condensed Matter · Physics 2024-06-18 Emily Krucker-Velasquez , James W. Swan , Zachary Sherman

3D non-LTE radiative transfer problems are computationally demanding, and this sets limits on the size of the problems that can be solved. So far Multilevel Accelerated Lambda Iteration (MALI) has been to the method of choice to perform…

Solar and Stellar Astrophysics · Physics 2017-03-15 Johan P. Bjørgen , Jorrit Leenaarts

I use cosmological simulations that incorporate a physically motivated approximation to three-dimensional radiative transfer that recovers correct asymptotic ionization front propagation speeds for some cosmologically relevant density…

Astrophysics · Physics 2009-10-31 Nickolay Y. Gnedin

Previously we identified a new class of early galaxy that we estimate contributes up to 30\% of the ionizing photons responsible for reionization. These are low mass halos in the range $M_h =10^{6.5}-10^{8} M_{\odot}$ that have been…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-07 Michael L Norman , Pengfei Chen , John H Wise , Hao Xu