The Power Spectrum of Turbulence in NGC 1333: Outflows or Large-Scale Driving? (2009)
Padoan, Paolo, Juvela, Mika, Kritsuk, Alexei G., Norman, Michael L.
Is the turbulence in cluster-forming regions internally driven by stellar outflows or the consequence of a large-scale turbulent cascade? We address this question by studying the turbulent energy...
Cosmological Radiation Hydrodynamics with ENZO (2009)
Norman, Michael L., Reynolds, Daniel R., So, Geoffrey C.
We describe an extension of the cosmological hydrodynamics code ENZO to include the self-consistent transport of ionizing radiation modeled in the flux-limited diffusion approximation. A novel...
Baryon Acoustic Oscillations in the Lyman Alpha Forest (2009)
Norman, Michael L., Paschos, Pascal, Harkness, Robert
We use hydrodynamic cosmological simulations in a (600 Mpc)^3 volume to study the observability of baryon acoustic oscillations (BAO) in the intergalactic medium as probed by Lyman alpha forest (LAF)...
Simulating Supersonic Turbulence in Magnetized Molecular Clouds (2009)
Kritsuk, Alexei G., Ustyugov, Sergey D., Norman, Michael L., Padoan, Paolo
We present results of large-scale three-dimensional simulations of weakly magnetized supersonic turbulence at grid resolutions up to 1024^3 cells. Our numerical experiments are carried out with the...
Piecewise Parabolic Method on a Local Stencil for Magnetized Supersonic Turbulence Simulation (2009)
Ustyugov, Sergey D., Popov, Mikhail V., Kritsuk, Alexei G., Norman, Michael L.
Stable, accurate, divergence-free simulation of magnetized supersonic turbulence is a severe test of numerical MHD schemes and has been surprisingly difficult to achieve due to the range of flow...
Xu, Hao, Li, Hui, Collins, David C., Li, Shengtai, Norman, Michael L.
We present self-consistent cosmological magnetohydrodynamic (MHD) simulations that simultaneously follow the formation of a galaxy cluster and the magnetic field ejection by an active galactic...
Hallman, Eric J., O'Shea, Brian W., Smith, Britton D., Burns, Jack O., Norman, Michael L.
Detection of the Warm-Hot Intergalactic Medium (WHIM) using Sunyaev-Zeldovich effect (SZE) surveys is an intriguing possibility, and one that may allow observers to quantify the amount of "missing...
Simulations of Supersonic Turbulence in Molecular Clouds: Evidence for a New Universality (2009)
Kritsuk, Alexei G., Ustyugov, Sergey D., Norman, Michael L., Padoan, Paolo
We use three-dimensional simulations to study the statistics of supersonic turbulence in molecular clouds. Our numerical experiments describe driven turbulent flows with an isothermal equation of...
Cosmological AMR MHD with Enzo (2009)
Collins, David C., Xu, Hao, Norman, Michael L., Li, Hui, Li, Shengtai
In this work, we present MHDEnzo, the extension of the cosmological code Enzo to include the effects magnetic fields through the ideal MHD approximation. We use a higher order Godunov Riemann solver...
Self-Consistent Solution of Cosmological Radiation-Hydrodynamics and Chemical Ionization (2009)
Reynolds, Daniel R., Hayes, John C., Paschos, Pascal, Norman, Michael L.
We consider a PDE system comprising compressible hydrodynamics, flux-limited diffusion radiation transport and chemical ionization kinetics in a cosmologically-expanding universe. Under an...
Population III Supernovae and the Assembly of the First Galaxies (2008)
Whalen, Daniel, Van Veelen, Bob, O'Shea, Brian W., Norman, Michael L.
Current numerical studies suggest that the first galaxies formed a few stars at a time and were enriched only gradually by the first heavy elements. However, the large box sizes in these models...
The Biermann Battery in Cosmological MHD Simulations of Population III Star Formation (2008)
Xu, Hao, O'Shea, Brian W., Collins, David C., Norman, Michael L., Li, Hui, Li, Shengtai
We report the results of the first self-consistent three-dimensional adaptive mesh refinement magnetohydrodynamical simulations of Population III star formation including the Biermann Battery effect....
Three Modes of Metal-Enriched Star Formation in the Early Universe (2008)
Smith, Britton D., Turk, Matthew J., Sigurdsson, Steinn, O'Shea, Brian W., Norman, Michael L.
Simulations of the formation of Population III (Pop III) stars suggest that they were much more massive than the Pop II and Pop I stars observed today. This is due to the collapse dynamics of...
Skillman, Samuel W., O'Shea, Brian W., Hallman, Eric J., Burns, Jack O., Norman, Michael L.
We present new results characterizing cosmological shocks within adaptive mesh refinement N-Body/hydrodynamic simulations that are used to predict non-thermal components of large-scale structure....
A cosmological AMR MHD module for Enzo (2008)
Xu, Hao, Collins, David C., Norman, Michael L., Li, Shengtai, Li, Hui
Magnetic fields play an important role in almost all astrophysical phenomena including star formation. But due to the difficulty in analytic modeling and observation, magnetic fields are still poorly...
Paschos, Pascal, Jena, Tridivesh, Tytler, David, Kirkman, David, Norman, Michael L.
We give a comprehensive statistical description of the Lyman-alpha absorption from the intergalactic medium in a hydrodynamic simulation at redshifts 0.1-1.6, the range of redshifts covered by HST...
Population III Star Formation and IMF (2008)
We review recent 3D cosmological hydrodynamic simulations of primordial star formation from cosmological initial conditions (Pop III.1) and from initial conditions that have been altered by radiative...
The Evolution Of Cosmic Ray Mediated Mhd Shocks : A Two-Fluid Approach (2008)
Byung-Il Jun, David A. Clarke, Michael L. Norman
We study the shock structure and acceleration efficiency of cosmic ray mediated MHD shocks both analytically and numerically by using a two-fluid model. Our model includes the dynamical effect of...
The Destruction of Cosmological Minihalos by Primordial Supernovae (2008)
Whalen, Daniel, Van Veelen, Bob, O'Shea, Brian W., Norman, Michael L.
We present numerical simulations of primordial supernovae in cosmological minihalos at $z \sim$ 20. We consider Type II supernovae, hypernovae, and pair instability supernovae (PISN) in halos from...
The destruction of cosmological minihalos by primordial supernovae (2008)
Whalen, Daniel, Veelen, B. Van, O'Shea, Brian W., Norman, Michael L.
We present numerical simulations of primordial supernovae in cosmological minihalos at z ~ 20. We consider Type II supernovae, hypernovae, and pair instability supernovae (PISN) in halos from 6.9 ×...
Cosmological radiative transfer codes comparison project - I. The static density field tests (2007)
Iliev, Ilian T., Ciardi, Benedetta, Alvarez, Marcelo A., Maselli, Antonella, Ferrara, Andrea, Gnedin, Nickolay Y., ...
Radiative transfer simulations are now at the forefront of numerical astrophysics. They are becoming crucial for an increasing number of astrophysical and cosmological problems; at the same time...
The Magnetic Collimation of Bipolar Outflows I: Adiabatic Simulations (2007)
James M. Stone, Michael L. Norman
The collimation of an isotropic, non-magnetic protostellar wind by an ordered magnetic field in the ambient medium is investigated using self-consistent magnetohydrodynamic simulations in...
The Magnetic Collimation of Bipolar Outflows I: Adiabatic Simulations (2007)
James Stone, Michael L. Norman
The collimation of an isotropic, non-magnetic protostellar wind by an ordered magnetic field in the ambient medium is investigated using self-consistent magnetohydrodynamic simulations in...
The Magnetic Collimation of Bipolar Outflows I: Adiabatic Simulations (2007)
James Stone, Michael L. Norman
The collimation of an isotropic, non-magnetic protostellar wind by an ordered magnetic field in the ambient medium is investigated using self-consistent magnetohydrodynamic simulations in...
Hierarchical Numerical Cosmology with Hydrodynamics: Methods and Code Tests (2007)
Peter Anninos, Michael L. Norman, David A. Clarke
this paper, we discuss the details of our code and the variety of test-bed calculations we have run. Section (II) outlines the basic equations we are solving for the gas and collisionless matter and...
A Hydrodynamic Simulation of Cluster Formation (2007)
We have developed a hybrid cosmological code to probe the baryonic gas dynamics of large cosmological structures. An adiabatic simulation of large scale structure formation has been performed, using...
National Center, Wenbo Y. Anninos, Michael L. Norman
We present the numerical techniques and tests used to construct and validate a computer code designed to study the multidimensional nonlinear hydrodynamics of large scale sheet structures in the...
The Three Dimensional Interaction of a Supernova Remnant with an Interstellar Cloud (2007)
James M. Stone, Michael L. Norman
We present the hydrodynamic evolution in three-dimensions of a spherical bubble embed-ded in a less dense uniform ambient medium as it interacts with a Mach 10 planar shock. This scenario is an...
RevMexAA (Serie de Conferencias), 9, 66-71 (2000) (2007)
We describe ZEUS-MP: a Multi-Physics, Massively-Parallel, Message-Passing code for astrophysical uid dynamics simulations in 3 dimensions. ZEUS-MP is a follow-on to the sequential ZEUS-2D and ZEUS-3D...
RevMexAA (Serie de Conferencias), 9, 66--71 (2000) (2007)
We describe ZEUS-MP: a Multi-Physics, Massively-Parallel, Message-Passing code for astrophysical fluid dynamics simulations in 3 dimensions. ZEUS-MP is a follow-on to the sequential ZEUS-2D and...
The Effect of Large-Scale Power on Simulated Spectra of the Lya forest (2007)
Tytler, David, Paschos, Pascal, Kirkman, David, Norman, Michael L., Jena, Tridivesh
We study the effects of box size on ENZO simulations of the intergalactic medium (IGM) at z = 2. We follow statistics of the cold dark matter (CDM) and the Lya absorption. We find that the larger...
Paschos, Pascal, Norman, Michael L., Bordner, James O., Harkness, Robert
We study the ionization and thermal evolution of the intergalactic medium during the epoch of \heii reionization by means of radiation hydrodynamical cosmological simulations. We post-process...
Can gravitational infall energy lead to the observed velocity dispersion in DLAs? (2007)
Razoumov, Alexei O., Norman, Michael L., Prochaska, Jason X., Sommer-Larsen, Jesper, Wolfe, Arthur M., Yang, Yi-Jung
The median observed velocity width v_90 of low-ionization species in damped Ly-alpha systems is close to 90 km/s, with approximately 10% of all systems showing v_90 > 210 km/s at z=3. We show that a...
Resonance Related Spiral Substructure in a Galactic Gaseous Disk (2007)
Yáñez, Miguel A., Norman, Michael L., Martos, Marco A., Hayes, John C.
We use high resolution 2D hydrodynamic simulations to study the formation of spiral substructure in the gaseous disk of a galaxy. The obtained gaseous response is driven by a self-consistent...
Photoionization of Clustered Halos by the First Stars (2007)
Whalen, Daniel, O'Shea, Brian W., Smidt, Joseph, Norman, Michael L.
We present numerical simulations of the photoevaporation of cosmological halos clustered around a 120 M$_\odot$ primordial star, confining our study to structures capable of hosting Population III...
Ionization Front Instabilities in Primordial H II Regions (2007)
Whalen, Daniel, Norman, Michael L.
Radiative cooling by metals in shocked gas mediates the formation of ionization front instabilities in the galaxy today that are responsible for a variety of phenomena in the interstellar medium,...
Why Do Only Some Galaxy Clusters Have Cool Cores? (2007)
Burns, Jack O., Hallman, Eric J., Gantner, Brennan, Motl, Patrick M., Norman, Michael L.
Flux-limited X-ray samples indicate that about half of rich galaxy clusters have cool cores. Why do only some clusters have cool cores while others do not? In this paper, cosmological N-body +...
How the First Stars Regulated Local Star Formation I: Radiative Feedback (2007)
Whalen, Daniel, O'Shea, Brian W., Smidt, Joseph, Norman, Michael L.
We present numerical simulations of how a 120 M$_\odot$ primordial star regulates star formation in nearby cosmological halos at $z \sim$ 20 by photoevaporation. Our models include nine-species...
O'Shea, Brian W., Norman, Michael L.
We examine aspects of primordial star formation in the presence of a molecular hydrogen-dissociating ultraviolet background. We compare a set of AMR hydrodynamic cosmological simulations using a...
Scaling Laws and Intermittency in Highly Compressible Turbulence (2007)
Kritsuk, Alexei G., Padoan, Paolo, Wagner, Rick, Norman, Michael L.
We use large-scale three-dimensional simulations of supersonic Euler turbulence to study the physics of a highly compressible cascade. Our numerical experiments describe non-magnetized driven...
Simulating Cosmological Evolution with Enzo (2007)
Norman, Michael L., Bryan, Greg L., Harkness, Robert, Bordner, James, Reynolds, Daniel, O'Shea, Brian, ...
In this paper we describe our massively parallel version of Enzo, a multiphysics, parallel, AMR application for simulating cosmological structure formation developed at UCSD and Columbia. We describe...
Hallman, Eric J., Burns, Jack O., Motl, Patrick M., Norman, Michael L.
We have analyzed a large sample of numerically simulated clusters to demonstrate the adverse effects resulting from use of X-ray fitted beta-model parameters with Sunyaev-Zeldovich effect (SZE) data....
The Statistics of Supersonic Isothermal Turbulence (2007)
Kritsuk, Alexei G., Norman, Michael L., Padoan, Paolo, Wagner, Rick
We present results of large-scale three-dimensional simulations of supersonic Euler turbulence with the piecewise parabolic method and multiple grid resolutions up to 2048^3 points. Our numerical...
Hallman, Eric J., O'Shea, Brian W., Burns, Jack O., Norman, Michael L., Harkness, Robert, Wagner, Rick
We present the first results from a new generation of simulated large sky coverage (~100 square degrees) Sunyaev-Zeldovich effect (SZE) cluster surveys using the cosmological adaptive mesh refinement...
Three-Dimensional Dynamical Instabilities in Galactic Ionization Fronts (2007)
Whalen, Daniel J., Norman, Michael L.
Ionization front instabilities have long been of interest for their suspected role in a variety of phenomena in the galaxy, from the formation of bright rims and 'elephant trunks' in nebulae to...
Padoan, Paolo, Nordlund, AAke, Kritsuk, Alexei G., Norman, Michael L., Li, Pak Shing
The Padoan and Nordlund model of the stellar initial mass function (IMF) is derived from low order statistics of supersonic turbulence, neglecting gravity (e.g. gravitational fragmentation, accretion...
The Power Spectrum of Supersonic Turbulence in Perseus (2006)
Padoan, Paolo, Juvela, Mika, Kritsuk, Alexei, Norman, Michael L.
We test a method of estimating the power spectrum of turbulence in molecular clouds based on the comparison of power spectra of integrated intensity maps and single-velocity-channel maps, suggested...
Beyond the Cool Core: The Formation of Cool Core Galaxy Clusters (2006)
Burns, Jack O., Hallman, Eric J., Gantner, Brennan, Motl, Patrick M., Norman, Michael L.
Why do some clusters have cool cores while others do not? In this paper, cosmological simulations, including radiative cooling and heating, are used to examine the formation and evolution of cool...
AMR Simulations of the Cosmological Light Cone: SZE Surveys of the Synthetic Universe (2006)
Hallman, Eric J., O'Shea, Brian W., Norman, Michael L., Wagner, Rick, Burns, Jack O.
We present preliminary results from simulated large sky coverage (~100 square degrees) Sunyaev-Zeldovich effect (SZE) cluster surveys using the cosmological adaptive mesh refinement N-body/hydro code...
High Resolution Simulations of Supersonic Turbulence in Molecular Clouds (2006)
Kritsuk, Alexei G., Wagner, Rick, Norman, Michael L., Padoan, Paolo
We present the results of three-dimensional simulations of supersonic Euler turbulence with grid resolutions up to 1024^3 points. Our numerical experiments describe nonmagnetized driven turbulent...
Introducing zeus-mp: a 3d, parallel, multiphysics code for astrophysical fluid dynamics (2006)
Introducing zeus-mp: a 3d, parallel, multiphysics code for astrophysical fluid dynamics
Can We Trust the Dust? Evidence of Dust Segregation in Molecular Clouds (2006)
Padoan, Paolo, Cambresy, Laurent, Juvela, Mika, Kritsuk, Alexei, Langer, William D., Norman, Michael L.
Maps of estimated dust column density in molecular clouds are usually assumed to reliably trace the total gas column density structure. In this work we present results showing a clear discrepancy...
O'Shea, Brian W., Norman, Michael L.
(abridged) We perform 12 extremely high resolution adaptive mesh refinement cosmological hydrodynamic simulations of Population III star formation in a Lambda CDM universe, varying the box size and...
Cosmological Radiative Transfer Codes Comparison Project I: The Static Density Field Tests (2006)
Iliev, Ilian T., Ciardi, Benedetta, Alvarez, Marcelo A., Maselli, Antonella, Ferrara, Andrea, Gnedin, Nickolay Y., ...
Radiative transfer simulations are now at the forefront of numerical astrophysics. They are becoming crucial for an increasing number of astrophysical and cosmological problems; at the same time...
Population III Star Formation in a Lambda WDM Universe (2006)
O'Shea, Brian W., Norman, Michael L.
In this paper we examine aspects of primordial star formation in a gravitino warm dark matter universe with a cosmological constant. We compare a set of simulations using a single cosmological...
Cosmological radiative transfer codes comparison project – I. The static density field tests (2006)
Iliev, Ilian T., Ciardi, Benedetta, Alvarez, Marcelo A., Maselli, Antonella, Ferrara, Andrea, Gnedin, Nickolay Y., ...
Hot Gas in Galaxy Clusters: Theory and Simulations (2005)
We review the theory of the formation of galaxy clusters and discuss their role as cosmological probes. We begin with the standard cosmological framework where we discuss the origin of the CDM matter...
Razoumov, Alexei O., Norman, Michael L., Prochaska, Jason X., Wolfe, Arthur M.
We use high resolution Eulerian hydrodynamics simulations to study kinematic properties of the low ionization species in damped Ly-alpha systems at redshift z=3. Our adaptive mesh refinement...
Ruling the Universe: An Improved Method for Measuring H_0 with Galaxy Clusters (2005)
Hallman, Eric J., Burns, Jack O., Motl, Patrick M., Norman, Michael L.
Withdrawn at the current time due to errors.
Hallman, Eric J., Motl, Patrick M., Burns, Jack O., Norman, Michael L.
We critically analyze the measurement of galaxy cluster gas masses, which is central to cosmological studies that rely on the galaxy cluster gas mass fraction. Using synthetic observations of...
Whalen, Daniel J., Norman, Michael L.
Radiation hydrodynamical transport of ionization fronts in the next generation of cosmological reionization simulations holds the promise of predicting UV escape fractions from first principles as...
The H I opacity of the intergalactic medium at redshifts 1.6 < z < 3.2 (2005)
Kirkman, David, Tytler, David, Suzuki, Nao, Melis, Carl, Hollywood, Susan, James, Kory, ...
We use high quality echelle spectra of 24 QSOs to provide a calibrated measurement of the total amount of Lyman-alpha forest absorption (DA) over the redshift range 2.2 < z < 3.2. Our measurement of...
Forming a Primordial Star in a Relic HII Region (2005)
O'Shea, Brian W., Abel, Tom, Whalen, Dan, Norman, Michael L.
There has been considerable theoretical debate over whether photoionization and supernova feedback from the first Population III stars facilitate or suppress the formation of the next generation of...
Motl, Patrick M., Hallman, Eric J., Burns, Jack O., Norman, Michael L.
We investigate empirical scaling relations between the thermal Sunyaev-Zeldovich effect (SZE) and cluster mass in simulated clusters of galaxies. The simulated clusters have been compiled from four...
Comparing AMR and SPH cosmological simulations - I. Dark matter and adiabatic simulations (2005)
O'Shea, Brian W., Nagamine, Kentaro, Springel, Volker, Hernquist, Lars, Norman, Michael L.
A Statistical Analysis of Intergalactic Medium Transmission Approaching Reionization (2004)
Paschos, Pascal, Norman, Michael L.
We use hydrodynamic cosmological simulations in a 9.6 Mpc box to explore the evolution of the intergalactic medium (IGM) transmissivity from z=2 through the epoch of reionization. Reionization is...
Adaptive Mesh Refinement for Supersonic Molecular Cloud Turbulence (2004)
Kritsuk, Alexei G., Norman, Michael L., Padoan, Paolo
We performed a series of three-dimensional numerical simulations of supersonic homogeneous Euler turbulence with adaptive mesh refinement (AMR) and effective grid resolution up to 1024^3 zones. Our...
A Solution to the Protostellar Accretion Problem (2004)
Padoan, Paolo, Kritsuk, Alexei, Norman, Michael L., Nordlund, Ake
Accretion rates of order 10^-8 M_\odot/yr are observed in young protostars of approximately a solar mass with evidence of circumstellar disks. The accretion rate is significantly lower for protostars...
Tytler, David, Kirkman, David, O'Meara, John M., Suzuki, Nao, Orin, Adam, Lubin, Dan, ...
We identify a concordant model for the intergalactic medium (IGM) at redshift z=1.9 that uses popular values for cosmological and astrophysical parameters and accounts for all baryons with an...
I review cosmological simulations of X-ray clusters. Simulations have increased in resolution dramatically and the effects of radiative cooling, star formation feedback, and chemical enrichment on...
Introducing Enzo, an AMR Cosmology Application (2004)
O'Shea, Brian W., Bryan, Greg, Bordner, James, Norman, Michael L., Abel, Tom, Harkness, Robert, ...
In this paper we introduce Enzo, a 3D MPI-parallel Eulerian block-structured adaptive mesh refinement cosmology code. Enzo is designed to simulate cosmological structure formation, but can also be...
The Impact of AMR in Numerical Astrophysics and Cosmology (2004)
I survey the use and impact of adaptive mesh refinement (AMR) simulations in numerical astrophysics and cosmology. Two basic techniques are in use to extend the dynamic range of Eulerian grid...
Comparing AMR and SPH Cosmological Simulations: I. Dark Matter & Adiabatic Simulations (2003)
O'Shea, Brian W., Nagamine, Kentaro, Springel, Volker, Hernquist, Lars, Norman, Michael L.
We compare two cosmological hydrodynamic simulation codes in the context of hierarchical galaxy formation: The SPH code GADGET, and the Eulerian AMR code ENZO. Both codes represent dark matter with...
The Formation of Self-Gravitating Cores in Turbulent Magnetized Clouds (2003)
Li, P. S., Norman, Michael L., Mac Low, Mordecai-Mark, Heitsch, Fabian
We use ZEUS-MP to perform high resolution, three-dimensional, super-Alfvenic turbulent simulations in order to investigate the role of magnetic fields in self-gravitating core formation within...
Did Massive Primordial Stars Preenrich the Lyman Alpha Forest? (2003)
Norman, Michael L., O'Shea, Brian W., Paschos, Pascal
We examine the dynamical evolution and statistical properties of the supernova ejecta of massive primordial stars in a cosmological framework to determine whether this first population of stars could...
Scaling Relations for Turbulence in the Multiphase Interstellar Medium (2003)
Kritsuk, Alexei G., Norman, Michael L.
We employ a generalization of the She & Leveque model to study velocity scaling relations based on our simulations of thermal instability--induced turbulence. Being a by-product of the interstellar...
Radiation Hydrodynamical Evolution of Primordial H II Regions (2003)
Whalen, Daniel, Abel, Tom, Norman, Michael L.
We simulate the ionization environment of z ~ 20 luminous objects formed within the framework of the current CDM cosmology and compute their UV escape fraction. These objects are likely single very...
On the Detectability of Turbulence and Bulk Flows in X-ray Clusters (2003)
Sunyaev, Rashid A., Norman, Michael L., Bryan, Greg L.
Cooling flows, cluster mergers and motions of galaxies through the cluster gas with supersonic and sonic velocities must lead to large scale motions of the intracluster medium (ICM). A...
Temperature Bias in Measurements of The Hubble Constant Using The Sunyaev-Zeldovich Effect (2003)
Lin, Wen-Ching, Norman, Michael L., Bryan, Greg L.
Measurements of the Hubble constant to distant galaxy clusters using the Sunyaev-Zeldovich effect are systematically low in comparison to values obtained by other means. These measurements usually...
Formation of Cool Cores in Galaxy Clusters via Hierarchical Mergers (2003)
Motl, Patrick M., Burns, Jack O., Loken, Chris, Norman, Michael L., Bryan, Greg
We present a new scenario for the formation of cool cores in rich galaxy clusters based on results from recent high spatial dynamic range, adaptive mesh Eulerian hydrodynamic simulations of...
Numerical Simulations of High Redshift Star Formation in Dwarf Galaxies (2002)
Tassis, Konstantinos, Abel, Tom, Bryan, Greg L., Norman, Michael L.
We present first results from three-dimensional hydrodynamic simulations of the high redshift formation of dwarf galaxies. The simulations use an Eulerian adaptive mesh refinement technique to follow...
Hayes, John C., Norman, Michael L.
This paper presents a new code for performing multidimensional radiation hydrodynamic (RHD) simulations on parallel computers involving anisotropic radiation fields and nonequilibrium effects. The...
Interstellar Phase Transitions Stimulated by Time-dependent Heating (2002)
Kritsuk, Alexei G., Norman, Michael L.
We use three-dimensional hydrodynamic numerical simulations to study phase transformations occurring in a clumpy interstellar gas exposed to time-dependent volumetric heating. To mimic conditions in...
Thermal Instability-Induced Interstellar Turbulence (2001)
Kritsuk, Alexei G., Norman, Michael L.
We study the dynamics of phase transitions in the interstellar medium by means of three-dimensional hydrodynamic numerical simulations. We use a realistic cooling function and generic nonequilibrium...
The Formation of the First Star in the Universe (2001)
Abel, Tom, Bryan, Greg L., Norman, Michael L.
We describe results from a fully self-consistent three dimensional hydrodynamical simulation of the formation of one of the first stars in the Universe. Dark matter dominated pre-galactic objects...
Bryan, Greg L., Abel, Tom, Norman, Michael L.
As an entry for the 2001 Gordon Bell Award in the "special" category, we describe our 3-d, hybrid, adaptive mesh refinement (AMR) code, Enzo, designed for high-resolution, multiphysics, cosmological...
Cosmological Hydrogen Reionization with Three Dimensional Radiative Transfer (2001)
Razoumov, Alexei O., Norman, Michael L., Abel, Tom, Scott, Douglas
We present new calculations of the inhomogeneous process of cosmological reionization by carefully following the radiative transfer in pre-computed hydrodynamical simulations of galaxy formation....
Greg L. Bryan, Tom Abel, Michael L. Norman
As an entry for the 2001 Gordon Bell Award in the “special ” category, we describe our 3-d, hybrid, adaptive mesh refinement (AMR) code Enzo designed for high-resolution, multiphysics,...
Baryons in the Warm-Hot Intergalactic Medium (2000)
Davé, Romeel, Cen, Renyue, Ostriker, Jeremiah P., Bryan, Greg L., Hernquist, Lars, Katz, Neal, ...
Approximately 30-40% of all baryons in the present day universe reside in a warm-hot intergalactic medium (WHIM), with temperatures between 10^5
First Structure Formation and the First Stars (2000)
Norman, Michael L., Abel, Tom, Bryan, Greg
We discuss the results of recent 3D simulations of first structure formation in relationship to the formation of the first stars. On the basis of a new, high-resolution AMR simulation (spatial...
Simulated Cluster Archive: A Computational Catalog of X-Ray Clusters in a Lambda-CDM Universe (2000)
Norman, Michael L., Daues, Greg, Nelson, Erik, Loken, Chris, Burns, Jack, Bryan, Greg, ...
We have simulated the evolution of a large sample of X-ray clusters in a Lambda-CDM universe at high spatial resolution using adaptive mesh refinement and placed the results in an online archive for...
Introducing ZEUS-MP: A 3D, Parallel, Multiphysics Code for Astrophysical Fluid Dynamics (2000)
We describe ZEUS-MP: a Multi-Physics, Massively-Parallel, Message-Passing code for astrophysical fluid dynamics simulations in 3 dimensions. ZEUS-MP is a follow-on to the sequential ZEUS-2D and...
The Formation and Fragmentation of Primordial Molecular Clouds (2000)
Abel, Tom, Bryan, Greg L., Norman, Michael L.
Many questions in physical cosmology regarding the thermal history of the intergalactic medium, chemical enrichment, reionization, etc. are thought to be intimately related to the nature and...
Introducing zeus-mp: a 3d, parallel, multiphysics code for astrophysical fluid dynamics (2000)
We describe ZEUS-MP: a Multi-Physics, Massively-Parallel, Message-Passing code for astrophysical uid dynamics simulations in 3 dimensions. ZEUS-MP is a follow-on to the sequential ZEUS-2D and ZEUS-3D...
Formation of Galactic Bulges (1999)
Gnedin, Nickolay Y., Norman, Michael L., Ostriker, Jeremiah P.
We use cosmological hydrodynamic simulations to investigate formation of galactic bulges within the framework of hierarchical clustering in a representative CDM cosmological model. We show that...
1. PERSONNEL During this report year the scientific staff consisted of the (1999)
R. Dickel, John R. Dickel, Brian Fields, Charles Gammie, ...
This report covers activities of the department for the period 1 September 1999 - 31 August 2000
Abel, Tom, Norman, Michael L., Madau, Piero
Many questions in physical cosmology regarding the thermal and ionization history of the intergalactic medium are now successfully studied with the help of cosmological hydrodynamical simulations....
The Formation and Fragmentation of Primordial Molecular Clouds (1998)
Abel, Tom, Bryan, Greg L., Norman, Michael L.
Many questions in physical cosmology regarding the thermal history of the intergalactic medium, chemical enrichment, reionization, etc. are thought to be intimately related to the nature and...
Simulating the Lyman Alpha Forest (1998)
Machacek, Marie E., Bryan, Greg L., Anninos, Peter, Meiksin, Avery, Norman, Michael L.
In this paper we review the importance of the Lyman alpha forest as a probe of structure formation in the universe. We first discuss the statistics used to describe the Lyman alpha forest and the...
Simulating Inhomogeneous Reionization (1998)
Norman, Michael L., Paschos, Paschalis, Abel, Tom
We describe an approach for incorporating radiative transfer into 3D hydrodynamic cosmological simulations. The method, while approximate, allows for a self-consistent treatment of self-shielding and...
Cosmological Adaptive Mesh Refinement (1998)
Norman, Michael L., Bryan, Greg L.
We describe a grid-based numerical method for 3D hydrodynamic cosmological simulations which is adaptive in space and time and combines the best features of higher order--accurate Godunov schemes for...
Resolving the Lyman-alpha Forest (1998)
Bryan, Greg L., Machacek, Marie, Anninos, Peter, Norman, Michael L.
In this paper we critically examine predictions of the Lya forest within the standard cold dark matter (SCDM) model, paying particular attention to the low end of the column-density distribution. We...
Norman, Michael L., Bryan, Greg L.
We report on results of recent, high resolution hydrodynamic simulations of the formation and evolution of X-ray clusters of galaxies carried out within a cosmological framework. We employ the highly...
First Structure Formation: II. Cosmic String + Hot Dark Matter Models (1997)
Abel, Tom, Stebbins, Albert, Anninos, Peter, Norman, Michael L.
We examine the structure of baryonic wakes in the cosmological fluid which would form behind GUT-scale cosmic strings at early times (redshifts z > 100) in a neutrino-dominated universe. We show,...
Physical Properties of the Lyman Alpha Forest in a Cold Dark Matter Cosmology (1997)
Zhang, Yu, Meiksin, Avery, Anninos, Peter, Norman, Michael L.
We discuss the origin and physical nature of the Lya forest absorption systems as found in hydrodynamical simulations of the Intergalactic Medium in a standard Cold Dark Matter cosmology (Omega=1,...
First Structure Formation: I. Primordial Star Forming Regions in hierarchical models (1997)
Abel, Tom, Anninos, Peter, Norman, Michael L., Zhang, Yu
We investigate the possibility of very early formation of primordial star clusters from high-\sigma perturbations in cold dark matter dominated structure formation scenarios. For this we have...
Primordial Star Forming Regions in a CDM Universe (1996)
Zhang, Yu, Norman, Michael L., Anninos, Peter, Abel, Tom
We developed a three-dimensional 2-level hierarchical cosmological code with a realistic and robust treatment of multi-species non-equilibrium ionization and radiative cooling processes, and use it...
Spectral Analysis of the Lyman Alpha Forest in a Cold Dark Matter Cosmology (1996)
Zhang, Yu, Anninos, Peter, Norman, Michael L., Meiksin, Avery
We simulate the Lya forest in a standard CDM universe using a 2-level hierarchical grid code to evolve the dark and baryonic matter components self-consistently. We solve the time-dependent...
Anninos, Peter, Zhang, Yu, Abel, Tom, Norman, Michael L.
We have developed a method of solving for multi-species chemical reaction flows in non--equilibrium and self--consistently with the hydrodynamic equations in an expanding FLRW universe. The method is...
Burns, Jack O., Ledlow, Michael J., Loken, Chris, Klypin, Anatoly, Voges, Wolfgang, Bryan, Greg L., ...
We present the first X-ray Luminosity Function (XLF) for an optically-selected sample of 49 nearby poor clusters of galaxies and a sample of 67 Abell clusters with z < 0.15. We have extended the...
Interaction of Rayleigh-Taylor Fingers and Circumstellar Clodlets in Young Supernova Remnants (1996)
Jun, Byung-Il, Jones, T. W., Norman, Michael L.
We discover a new dynamical mechanism that significantly enhances the growth of Rayleigh-Taylor fingers developed near the contact interface between the supernova ejecta and swept-up ambient gas in...
On the Origin of Radial Magnetic Fields in Young Supernova Remnants (1996)
Jun, Byung-Il, Norman, Michael L.
We study the radio emission from young supernova remnants by means of 3D numerical MHD simulations of the Rayleigh-Taylor instability in the shell of the remnant. The computation is carried out in...
Cosmological Filaments and Minivoids: The Origin of Intergalactic Absorption (1996)
Zhang, Yu, Meiksin, Avery, Anninos, Peter, Norman, Michael L.
Soon after the first QSO was identified, Gunn & Peterson searched for the expected characteristic absorption trough on the blueward side of Lya in the spectrum of the QSO due to an Intergalactic...
On the Origin of Strong Magnetic Fields in Young Supernova Remnants (1996)
Jun, Byung-Il, Norman, Michael L.
Young supernova remnants such as Tycho generally exhibit a bright circular clumpy shell in both radio and X-ray emission. For several young remnants, various arguments suggest that the magnetic field...
A Multi-Species Model for Hydrogen and Helium Absorbers in Lyman-Alpha Forest Clouds (1995)
Zhang, Yu, Anninos, Peter, Norman, Michael L.
We have performed a multi-species hydrodynamical simulation of the formation and evolution of Lyman alpha clouds in a flat CDM dominated universe with an external flux of ionizing radiation. We solve...
The Evolution of X-Ray Clusters in a Cold Plus Hot Dark Matter Universe (1994)
Bryan, Greg L., Klypin, Anatoly, Loken, Chris, Norman, Michael L., Burns, Jack O.
We present the first self-consistently computed results on the evolution of X-ray properties of galaxy clusters in a Cold + Hot Dark Matter (CHDM) model. We have performed a hydrodynamic plus N-body...
A Comparison of Cosmological Hydrodynamic Codes (1994)
Kang, Hyesung, Ostriker, Jeremiah P., Cen, Renyue, Ryu, Dongsu, Hernquist, Lars, Evrard, August E., ...
We present a detailed comparison of the simulation results of various cosmological hydrodynamic codes. Starting with identical initial conditions based on the Cold Dark Matter scenario for the growth...
The Evolution of X-ray Clusters in a Cold plus Hot Dark Matter Universe (1994)
Greg L. Bryan, Anatoly Klypin, Chris Loken, Michael L. Norman, Jack O. Burns
We present the first self-consistently computed results on the evolution of X-ray properties of galaxy clusters in a Cold + Hot Dark Matter (CHDM) model. We have performed a hydrodynamic plus N-body...
X-Ray Clusters From A High Resolution Hydrodynamic Ppm Simulation Of The Cdm Universe (1994)
Greg Bryan, Renyue Cen, Michael L. Norman, Jeremiah P. Ostriker, James M. Stone
A new three dimensional Piecewise Parabolic Method (PPM) based hydrodynamic code is utilized to compute the distribution of hot gas in the standard COBE normalized CDM universe. Utilizing periodic...
Nonlinear Growth of Dynamical Overstabilities in Blast Waves (1993)
Blast waves have been shown by Vishniac to be subject to an oscillating instability, with growth occurring when the blast wave is thin enough. The nonlinear development of this overstability has not...
Cosmic Explorer: A Virtual Reality Environment For Exploring Cosmic Data (1993)
Deyang Song, Michael L. Norman
Supercomputer simulations now can produce multi-level, multi-scale, large data sets that require new techniques in scientific visualization and higher levels of hardware performance. We are exploring...
James M. Stone, Dimitri Mihalas, Michael L. Norman
In this, the third of a series of three papers, we conclude a detailed description of ZEUS-2D, a numerical code for the simulation of fluid dynamical flows in astrophysics including a self-consistent...
James M. Stone, Michael L. Norman
In this, the first of a series of three papers, we begin a detailed description of ZEUS-2D, a numerical code for the simulation of fluid dynamical flows in astrophysics including a self-consistent...
James Stone And, James M. Stone, Michael L. Norman
In this, the second of a series of three papers, we continue a detailed description of ZEUS-2D, a numerical code for the simulation of fluid dynamical flows in astrophysics including a...
James Stone And, James M. Stone, Michael L. Norman
In this, the first of a series of three papers, we begin a detailed description of ZEUS-2D, a numerical code for the simulation of fluid dynamical flows in astrophysics including a self-consistent...
James Stone National, James M. Stone, Dimitri Mihalas, Michael L. Norman
In this, the third of a series of three papers, we conclude a detailed description of ZEUS-2D, a numerical code for the simulation of fluid dynamical flows in astrophysics including a self-consistent...
James Stone, Dimitri Mihalas, Michael L. Norman
In this, the third of a series of three papers, we conclude a detailed description of ZEUS-2D, a numerical code for the simulation of fluid dynamical flows in astrophysics including a self-consistent...
James Stone, Michael L. Norman
In this, the second of a series of three papers, we continue a detailed description of ZEUS-2D, a numerical code for the simulation of fluid dynamical flows in astrophysics including a...
A Test Suite for Magnetohydrodynamical Simulations (1992)
James M. Stone, John F. Hawley, Charles R. Evans, Michael L. Norman
We have drawn together in this paper a collection of magnetohydrodynamic (MHD) problems that will provide researchers who have interests in modeling MHD phenomena with a battery of tests (a...
James Stone, Michael L. Norman
In this, the first of a series of three papers, we begin a detailed description of ZEUS-2D, a numerical code for the simulation of fluid dynamical flows in astrophysics including a self-consistent...
James M. Stone, Michael L. Norman
In this, the second of a series of three papers, we continue a detailed description of ZEUS-2D, a numerical code for the simulation of fluid dynamical flows in astrophysics including a...