Radiative Transfer Modeling of Lyman Alpha Emitters: I. Statistics of Spectra and Luminosity (2009)
Zheng, Zheng, Cen, Renyue, Trac, Hy, Miralda-Escude, Jordi
We combine a cosmological reionization simulation with box size of 100Mpc/h on a side and a Monte Carlo Lyman-alpha (Lya) radiative transfer code to model Lyman Alpha Emitters (LAEs) at z~5.7. The...
Simulations of the Microwave Sky (2009)
Sehgal, Neelima, Bode, Paul, Das, Sudeep, Hernandez-Monteagudo, Carlos, Huffenberger, Kevin, Lin, Yen-Ting, ...
We create realistic, full-sky, half-arcminute resolution simulations of the microwave sky matched to the most recent astrophysical observations. The primary purpose of these simulations is to test...
Probing the Epoch of Reionization with the Lyman Alpha Forest at z~4-5 (2009)
Cen, Renyue, McDonald, Patrick, Trac, Hy, Loeb, Abraham
The inhomogeneous cosmological reionization process leaves tangible imprints in the intergalactic medium down to z=4-5. The Lyman-alpha forest flux power spectrum provides a potentially powerful...
Computer Simulations of Cosmic Reionization (2009)
The cosmic reionization of hydrogen was the last major phase transition in the evolution of the universe, which drastically changed the ionization and thermal conditions in the cosmic gas. To the...
Galaxy Statistics in Pencil-beam Surveys at High Redshifts (2009)
Muñoz, Joseph A., Trac, Hy, Loeb, Abraham
Surveys of faint galaxies at high redshifts often result in a "pencil-beam" geometry that is much longer along the line-of-sight than across the sky. We explore the effects of this geometry on the...
Xu, Yidong, Chen, Xuelei, Fan, Zuhui, Trac, Hy, Cen, Renyue
Using high redshift radio sources as background, the 21cm forest observations probe the neutral hydrogen absorption signatures of early structures along the lines of sight. Directly sensitive to the...
Cosmology from the Highly-Redshifted 21 cm Line (2009)
Furlanetto, Steven, Lidz, Adam, Loeb, Abraham, McQuinn, Matthew, Pritchard, Jonathan, Shapiro, Paul, ...
One of the next decade's most exciting prospects is to explore the cosmic "dark ages," during which the first stars in the Universe formed, with the 21 cm line of neutral hydrogen. At z>6, this light...
Astrophysics from the Highly-Redshifted 21 cm Line (2009)
Furlanetto, Steven, Lidz, Adam, Loeb, Abraham, McQuinn, Matthew, Pritchard, Jonathan, Aguirre, James, ...
The cosmic dark ages and the epoch of reionization, during which the first generations of stars and galaxies formed, are among the most compelling frontiers of extragalactic astrophysics and...
Cosmic reionization and the 21 cm signal: comparison between an analytical model and a simula (2008)
Santos, Mário G., Amblard, Alexandre, Pritchard, Jonathan, Trac, Hy, Cen, Renyue, Cooray, Asantha
We measure several properties of the reionization process and the corresponding low-frequency 21 cm signal associated with the neutral hydrogen distribution, using a large volume, high-resolution...
Trac, Hy, Cen, Renyue, Loeb, Abraham
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...
Santos, Mario G., Amblard, Alexandre, Pritchard, Jonathan, Trac, Hy, Cen, Renyue, Cooray, Asantha
We measure several properties of the reionization process and the corresponding low-frequency 21-cm signal associated with the neutral hydrogen distribution, using a large volume, high resolution...
Cosmological HII Bubble Growth During Reionization (2007)
Shin, Min-Su, Trac, Hy, Cen, Renyue
We present general properties of ionized hydrogen (HII) bubbles and their growth based on a state-of-the-art large-scale (100 Mpc/h) cosmological radiative transfer simulation. The simulation...
The Topology of Cosmological Reionization (2007)
Lee, Khee-Gan, Cen, Renyue, Gott III, J. Richard, Trac, Hy
Using the largest cosmological reionization simulation to-date (~24 billion particles), we use the genus curve to quantify the topology of neutral hydrogen distribution on scales > 1 Mpc as it...
The Cosmic Code Comparison Project (2007)
Heitmann, Katrin, Lukic, Zarija, Fasel, Patricia, Habib, Salman, Warren, Michael S., White, Martin, ...
Current and upcoming cosmological observations allow us to probe structures on smaller and smaller scales, entering highly nonlinear regimes. In order to obtain theoretical predictions in these...
Radiative transfer simulations of cosmic reionization I: methodology and initial results (2006)
We present a new hybrid code for large volume, high resolution simulations of cosmic reionization, which utilizes a N-body algorithm for dark matter, physically motivated prescriptions for baryons...
Sehgal, Neelima, Trac, Hy, Huffenberger, Kevin, Bode, Paul
We study the ability of three-frequency, arcminute-resolution microwave measurements to detect galaxy clusters via their Sunyaev-Zel'dovich (SZ) distortion of the microwave background. For this...
The thermal Sunyaev-Zel'dovich Signature of Baryons in the Local Universe (2006)
Hernandez-Monteagudo, Carlos, Trac, Hy, Jimenez, Raul, Verde, Licia
Using cosmological hydrodynamical simulations, we investigate the prospects of the thermal Sunyaev-Zel'dovich (tSZ) effect to detect the missing baryons in the local universe. We find that at least...
A comparison of hydrodynamics techniques for modelling collisions between main sequence stars (2006)
Trac, Hy, Sills, Alison, Pen, Ue-Li
An Eulerian TVD code and a Lagrangian SPH code are used to simulate the off-axis collision of equal-mass main sequence stars in order to address the question of whether stellar mergers can produce a...
Can sterile neutrinos be the dark matter? (2006)
Seljak, Uros, Makarov, Alexey, McDonald, Patrick, Trac, Hy
We use the Ly-alpha forest power spectrum measured by the SDSS and high-resolution spectroscopy observations in combination with cosmic microwave background and galaxy clustering constraints to place...
The kinetic Sunyaev-Zel'dovitch effect as a dark energy probe (2005)
DeDeo, Simon, Spergel, David N., Trac, Hy
Upcoming observatories will be able to detect the kinetic Sunyaev-Zel'dovitch (kSZ) effect with unprecendented signal-to-noise, and cross-correlations with foreground signals such as galaxy counts...
Dependence of the non-linear mass power spectrum on the equation of state of dark energy (2005)
McDonald, Patrick, Trac, Hy, Contaldi, Carlo
We present N-body simulation calculations of the dependence of the power spectrum of non-linear cosmological mass density fluctuations on the equation of state of the dark energy, w=p/rho. At fixed...
Towards optimal parallel PM N-body codes: PMFAST (2004)
Merz, Hugh, Pen, Ue-Li, Trac, Hy
We present a new parallel PM N-body code named PMFAST that is freely available to the public. PMFAST is based on a two-level mesh gravity solver where the gravitational forces are separated into long...
Out-of-Core Hydrodynamic Simulations for Cosmological Applications (2004)
We present an out-of-core hydrodynamic code for high resolution cosmological simulations that require terabytes of memory. Out-of-core computation refers to the technique of using disk space as...
The intergalactic medium temperature and Compton y parameter (2004)
Zhang, Pengjie, Pen, Ue-Li, Trac, Hy
(Abridged) The precision modeling of the thermal Sunyaev Zeldovich (SZ) effect and future high accuracy measurements will provide a powerful way to constrain the thermal history of the universe. In...
Abstract Out-of-core Hydrodynamic Simulations of Cosmological Structure Formation (2004)
Astrophysical and cosmological structure formation are challenging problems because they involve dynamical and hydrodynamical processes that can span a large range in scale, mass, and energy....
A Moving Frame Algorithm for High Mach Number Hydrodynamics (2003)
We present a new approach to Eulerian computational fluid dynamics that is designed to work at high Mach numbers encountered in astrophysical hydrodynamic simulations. The Eulerian fluid conservation...
Zhang, Pengjie, Pen, Ue-Li, Trac, Hy
The kinetic SZ effect, which is the dominant CMB source at arc-minute scales and $\nu \sim 217$ Ghz, probes the ionized gas peculiar momentum up to the epoch of reionization and is a sensitive...
A Primer on Eulerian Computational Fluid Dynamics for Astrophysics (2002)
We present a pedagogical review of some of the methods employed in Eulerian computational fluid dynamics (CFD). Fluid mechanics is governed by the Euler equations, which are conservation laws for...
Hydrodynamical Simulations of the IGM at High Mach Numbers (2002)
Trac, Hy, Zhang, Pengjie, Pen, Ue-Li
We present a new approach to doing Eulerian computational fluid dynamics that is designed to work at high Mach numbers encountered in hydrodynamical simulations of the IGM. In conventional Eulerian...
Topology of the Las Campanas Redshift Survey (2000)
Trac, Hy, Mitsouras, Dimitris, Hickson, Paul, Brandenberger, Robert H.
The topology of the Las Campanas Redshift Survey is analyzed using Minkowski functional statistics, taking into account the selection effects of the survey. The results are compared with the...