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...
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...
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...
Crawling the Cosmic Network: Exploring the Morphology of Structure in the Galaxy Distribution (2009)
Bond, Nicholas, Strauss, Michael, Cen, Renyue
Although coherent large-scale structures such as filaments and walls are apparent to the eye in galaxy redshift surveys, they have so far proven difficult to characterize with computer algorithms....
Cooke, Jeff, Cooray, Asantha, Chary, Ranga-Ram, Bromm, Volker, Cen, Renyue, Ellis, Richard, ...
The cosmic dark ages are the mysterious epoch during which the pristine gas began to condense and ultimately form the first stars. Although these beginnings have long been a topic of theoretical...
Non-Radiative Test of a New SPH Scheme (2009)
Kawata, Daisuke, Okamoto, Takashi, Cen, Renyue, Gibson, Brad K.
We adapt new schemes of gravitational N-body dynamics and smoothed particle hydrodynamics (SPH) to the tree N-body/SPH galactic chemodynamics code GCD+. The applied new schemes include the adaptive...
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...
Cooray, Asantha, Amblard, Alexandre, Beichman, Charles, Benford, Dominic, Bernstein, Rebecca, Bock, James, ...
(Brief Summary) What is the total radiative content of the Universe since the epoch of recombination? The extragalactic background light (EBL) spectrum captures the redshifted energy released from...
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...
Ionizing Photon Escape Fractions from High Redshift Dwarf Galaxies (2008)
It has been argued that low-luminosity dwarf galaxies are the dominant source of ionizing radiation during cosmological reionization. The fraction of ionizing radiation that escapes into the...
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...
Galaxy Size Problem at z=3: Simulated Galaxies Are Too Small (2008)
Joung, M. K. Ryan, Cen, Renyue, Bryan, Greg
Using state-of-the-art adaptive mesh refinement cosmological hydrodynamic simulations with a spatial resolution of proper 0.21kpc/h in refined subregions embedded within a comoving cosmological...
Correlations between O VI Absorbers and Galaxies at Low Redshift (2008)
Ganguly, Rajib, Cen, Renyue, Fang, Taotao, Sembach, Kenneth
We investigate the relationship between galaxies and metal-line absorption systems in a large-scale cosmological simulation with galaxy formation. Our detailed treatment of metal enrichment and...
Renyue Cen, Anil E. Deane, Paul F. Fischer, Henry M. Tufo
This paper describes the model, its parallel implementation and its performance results and presents simulation results for a range of heating and rotation rates. The present simulations also make...
Velocity Correlations Of Galaxy Clusters (2007)
Renyue Cen, Neta A. Bahcall, Mirt Gramann
We determine the velocity correlation function, pairwise peculiar velocity difference, and root-mean-square pairwise peculiar velocity dispersion of rich clusters of galaxies, as a function of pair...
Determining the Amplitude of Mass Fluctuations in the Universe (2007)
Xiaohui Fan, Neta A. Bahcall, Renyue Cen
We present a method for determining the rms mass fluctuations on 8 h \Gamma1 Mpc scale, oe 8 . The method utilizes the rate of evolution of the abundance of rich clusters of galaxies. Using the...
The Galaxy Pairwise Velocity Dispersion as a Function of Local Density (2007)
Michael Strauss, Jeremiah P. Ostriker, Renyue Cen
The standard method of measuring the galaxy pairwise velocity dispersion on small scales via the anisotropy in the two-point correlation function in redshift space suffers from the fact that it is a...
We study the projection effects on various observables of clusters of galaxies at zero redshift, including cluster richness, velocity dispersion, temperature, X-ray luminosity, three total mass...
We propose a simple yet powerful statistic, \Delta ø0 , which is the fraction of a quasar spectrum with Lyff optical depth greater than ø 0 and can be easily applied to existing observations as...
The Physical Origin of Scale Dependent Bias in Cosmological Simulations (2007)
Michael Blanton, Renyue Cen, Jeremiah P. Ostriker, Michael A. Strauss, Mpc To
Using large-scale hydrodynamic simulations with heuristic criteria for galaxy formation, we investigate how the galaxy field is related to physical parameters, such as the mass density and the gas...
The Protogalactic Origin for Cosmic Magnetic Fields (2007)
Russell M. Kulsrud, Renyue Cen, Jeremiah P. Ostriker, Dongsu Ryu
It is demonstrated that strong magnetic fields are produced from a zero initial magnetic field during the pregalactic era, when galaxies are first forming. Their development proceeds in three phases....
Jaan Einasto, Maret Einasto, Erik Tago, Alexei A. Starobinsky, Volker Muller, Alexander Knebe, ...
The primordial spectrum
A Parallel Cosmological Hydrodynamics Code (2007)
Paul W. Bode, Guohong Xu, Renyue Cen
Understanding the formation by gravitational collapse of galaxies and the large-scale structure of the universe is a nonlinear, multi-scale, multicomponent problem. This complex process involves...
Gamma-Ray Bursts May Be Biased Tracers of Star Formation (2007)
Based on a simulation of galaxy formation in the standard cosmological model, we suggest that a consistent picture for Gamma-Ray Bursts and star formation may be found that is in broad agreement with...
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...
Gravitational Stability of Circumnuclear Disks in Elliptical Galaxies (2007)
Kawata, Daisuke, Cen, Renyue, Ho, Luis C.
A significant fraction of nearby elliptical galaxies are known to have high density gas disks in their circumnuclear (CN) region (0.1 to a few kpc). Yet, ellipticals, especially luminous ones, show...
Lower Metal Enrichment of Virialized Gas in Minihalos (2007)
Cen, Renyue, Riquelme, Mario A.
We differentiate between the metal enrichment of the gas in virialized minihalos and that of the intergalactic medium at high redshift, pertinent to cosmological reionization, with the initial...
Kang, Hyesung, Ryu, Dongsu, Cen, Renyue, Ostriker, J. P.
Cosmological shock waves result from supersonic flow motions induced by hierarchical clustering of nonlinear structures in the universe. These shocks govern the nature of cosmic plasma through...
Grand Unification II: Hot Accretion and AGN Jets (2007)
We show that a quasi-spherical (QS) hot accretion flow is expected to operate in all SMBHs, with its rate being capped at dot m_QS,max~0.001 (M/1E8Msun) in units of the Eddington rate. It is then...
Gravitational stability of circumnuclear disks in elliptical galaxies (2007)
Kawata, Daisuke, Cen, Renyue, Ho, Luis C.
A significant fraction of nearby elliptical galaxies are known to have high-density gas disks in their circumnuclear (CN) region (0.1 to a few kpc). Yet ellipticals, especially luminous ones, show...
Gravitational stability of circumnuclear disks in elliptical galaxies (2007)
Kawata, Daisuke, Cen, Renyue, Ho, Luis C.
A significant fraction of nearby elliptical galaxies are known to have high-density gas disks in their circumnuclear (CN) region (0.1 to a few kpc). Yet ellipticals, especially luminous ones, show...
Gravitational stability of circumnuclear disks in elliptical galaxies (2007)
Kawata, Daisuke, Cen, Renyue, Ho, Luis C.
A significant fraction of nearby elliptical galaxies are known to have high-density gas disks in their circumnuclear (CN) region (0.1 to a few kpc). Yet ellipticals, especially luminous ones, show...
Gravitational stability of circumnuclear disks in elliptical galaxies (2007)
Kawata, Daisuke, Cen, Renyue, Ho, Luis C.
A significant fraction of nearby elliptical galaxies are known to have high-density gas disks in their circumnuclear (CN) region (0.1 to a few kpc). Yet ellipticals, especially luminous ones, show...
Gravitational stability of circumnuclear disks in elliptical galaxies (2007)
Kawata, Daisuke, Cen, Renyue, Ho, Luis C.
A significant fraction of nearby elliptical galaxies are known to have high-density gas disks in their circumnuclear (CN) region (0.1 to a few kpc). Yet ellipticals, especially luminous ones, show...
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...
CosmoMHD: A Cosmological Magnetohydrodynamics Code (2006)
Li, Shengtai, Li, Hui, Cen, Renyue
In this era of precision cosmology, a detailed physical understanding on the evolution of cosmic baryons is required. Cosmic magnetic fields, though still poorly understood, may represent an...
Topology of structure in the Sloan Digital Sky Survey: model testing (2006)
Gott III, J. Richard, Hambrick, D. Clay, Vogeley, Michael S., Kim, Juhan, Park, Changbom, Choi, Yun-Young, ...
We measure the three-dimensional topology of large-scale structure in the Sloan Digital Sky Survey (SDSS). This allows the genus statistic to be measured with unprecedented statistical accuracy. The...
It is shown that, if gas accretion via a disk onto the central supermassive black hole is efficient only for surface density Sigma >= 10 g/cm^2, the black hole mass - galactic bulge velocity...
Lensing of 21cm Absorption "Halos" of $z\sim$20-30 First Galaxies (2006)
Zhang, Pengjie, Zheng, Zheng, Cen, Renyue
Extended 21cm absorption regions (dubbed ``21cm absorption halos'') around first galaxies at $z\sim 30$ are likely the first distinctive structures accessible to radio observations. Though the radio...
Nagamine, Kentaro, Ostriker, Jeremiah P., Fukugita, Masataka, Cen, Renyue
Taking three independent approaches, we investigate the simultaneous constraints set on the cosmic star formation history from various observations, including stellar mass density and extragalactic...
Nagamine, Kentaro, Cen, Renyue, Furlanetto, Steven R., Hernquist, Lars, Night, Christopher, Ostriker, Jeremiah P.
Cosmological hydrodynamic simulations have significantly improved over the past several years, and we have already shown that the observed properties of Lyman-break galaxies (LBGs) at z=3 can be...
Population-III (Pop-III) starformation (SF) is thought to be quenched when the metallicity of the star-forming gas reaches a critical level. At high z, when the general intergalactic medium (IGM) was...
Origin of two distinct populations in dwarf spheroidal galaxies (2006)
Kawata, Daisuke, Arimoto, Nobuo, Cen, Renyue, Gibson, Brad K.
We study the chemical and kinematic properties of the first galaxies that formed at high redshift, using high-resolution cosmological numerical simulations, and compare them with the recent...
Origin of two distinct populations in dwarf spheroidal galaxies (2006)
Kawata, Daisuke, Arimoto, Nobuo, Cen, Renyue, Gibson, Brad K.
We study the chemical and kinematic properties of the first galaxies that formed at high redshift, using high-resolution cosmological numerical simulations, and compare them with the recent...
Origin of two distinct populations in dwarf spheroidal galaxies (2006)
Kawata, Daisuke, Arimoto, Nobuo, Cen, Renyue, Gibson, Brad K.
We study the chemical and kinematic properties of the first galaxies that formed at high redshift, using high-resolution cosmological numerical simulations, and compare them with the recent...
Origin of two distinct populations in dwarf spheroidal galaxies (2006)
Kawata, Daisuke, Arimoto, Nobuo, Cen, Renyue, Gibson, Brad K.
We study the chemical and kinematic properties of the first galaxies that formed at high redshift, using high-resolution cosmological numerical simulations, and compare them with the recent...
Origin of two distinct populations in dwarf spheroidal galaxies (2006)
Kawata, Daisuke, Arimoto, Nobuo, Cen, Renyue, Gibson, Brad K.
We study the chemical and kinematic properties of the first galaxies that formed at high redshift, using high-resolution cosmological numerical simulations, and compare them with the recent...
Where Are the Baryons? II: Feedback Effects (2005)
Cen, Renyue, Ostriker, Jeremiah P.
Numerical simulations of the intergalactic medium have shown that at the present epoch a significant fraction (40-50%) of the baryonic component should be found in the (T~10^6K) Warm-Hot...
Where Are the Baryons? III: Non-Equilibrium Effects and Observables (2005)
Numerical simulations of the intergalactic medium have shown that at the present epoch a significant fraction (40-50%) of the baryonic component should be found in the (T~10^6K) Warm-Hot...
Detection and Fundamental Applications of Individual First Galaxies (2005)
First galaxies formed within halos of mass M=E7.5-E9 Msun at z=30-40 in the standard cold dark matter (CDM) universe may each display an extended hydrogen 21-cm absorption halo against the cosmic...
Origin of Two Distinct Populations in Dwarf Spheroidal Galaxies (2005)
Kawata, Daisuke, Arimoto, Nobuo, Cen, Renyue, Gibson, Brad K.
We study the chemical and kinematic properties of the first galaxies which formed at a high redshift, using high resolution cosmological numerical simulations, and compared them with the recent...
Very Large H II Regions Around Proto-Clusters of Galaxies During Reionization (2005)
The physical basis for the belief that the abundant old dwarf galaxies seen in present-day galaxy clusters formed before reionization of the universe is very compelling, because (1) the observed...
The observed luminosity function (LF) of satellite galaxies shows several interesting features that require a better understanding of gas-thermodynamic processes and feedback effects related to...
Galactic Wind Effects on the Lyman-alpha Absorption in the Vicinity of Galaxies (2005)
Kollmeier, Juna A., Miralda-Escude, Jordi, Cen, Renyue, Ostriker, Jeremiah P.
We present predictions of Ly-alpha forest-galaxy correlations at z=3 from Eulerian simulations that include the effects of galactic winds, driven primarily by supernova explosions. Galactic winds...
Massive galaxies in cosmological simulations: ultraviolet-selected sample at redshift z=2 (2005)
Nagamine, Kentaro, Cen, Renyue, Hernquist, Lars, Ostriker, Jeremiah P., Springel, Volker
Massive galaxies at Z = 2 in cosmological hydrodynamic simulations (2005)
Nagamine, Kentaro, Cen, Renyue, Hernquist, Lars, Ostriker, Jeremiah P., Springel, Volker
Massive galaxies at redshift 2 in cosmological hydrodynamic simulations (2004)
Nagamine, Kentaro, Cen, Renyue, Hernquist, Lars, Ostriker, Jeremiah P., Springel, Volker
We study the properties of galaxies at z=2 in a Lambda cold dark matter universe, using two different types of hydrodynamic simulation methods -- Eulerian TVD and smoothed particle hydrodynamics...
At redshifts beyond z>6, as the mean fraction of neutral hydrogen x_HI in the intergalactic medium (IGM) increases, the line flux of Lyman alpha (Lya) emitters can be significantly suppressed, which...
Shock-Heated Gas in the Large Scale Structure of the Universe (2004)
Kang, Hyesung, Ryu, Dongsu, Cen, Renyue, Song, Doojong
Cosmological shock waves play a major role in heating baryonic gas in the large scale structure of the universe. In this contribution we study the shock-heated gas in connection with shocks...
Signatures of Galactic Superwinds: Inhomogeneous Metal Enrichment of the Lyman Alpha Forest (2004)
Cen, Renyue, Nagamine, Kentaro, Ostriker, Jeremiah P.
We investigate possible signatures of feedback from galactic superwinds on the metallicity of the Lyman alpha forest, using a set of high resolution hydrodynamic simulations of a Lambda cold dark...
Massive galaxies in cosmological simulations: UV-selected sample at redshift z=2 (2004)
Nagamine, Kentaro, Cen, Renyue, Hernquist, Lars, Ostriker, Jeremiah P., Springel, Volker
We study the properties of galaxies at z=2 in a Lambda CDM universe, using two different types of hydrodynamic simulation methods (Eulerian TVD and SPH) and a spectrophotometric analysis in the Un,...
Transition From Population III to Population II Stars (2004)
The transition from Population III to Population II stars is determined by the presence of a sufficient amount of metals, in particular, oxygen and carbon. The vastly different yields of these...
A Two-Fluid Thermally-Stable Cooling Flow Model (2004)
A new model for cooling flows in X-ray clusters, capable of naturally explaining salient features observed, is proposed. The only requirement is that a significant relativistic component, in the form...
Implications of the Lyman alpha Emission Line from a Candidate z=10 Galaxy (2004)
Cen, Renyue, Haiman, Zoltan, Mesinger, Andrei
The recently discovered z=10 galaxy (Pello et al 2004) has a strong Lyman alpha emission line that is consistent with being surprisingly symmetric, even given the relatively poor quality of its...
Properties of Cold Dark Matter Halos at z>6 (2004)
Cen, Renyue, Dong, Feng, Bode, Paul, Ostriker, Jeremiah P.
We compute the properties of dark matter halos with mass $10^{6.5}-10^9\msun$ at redshift $z=6-11$ in the standard cold dark matter cosmological model, utilizing a very high resolution N-body...
Probing the Reionization History Using the Spectra of High-Redshift Sources (2004)
Mesinger, Andrei, Haiman, Zoltan, Cen, Renyue
We quantify and discuss the footprints of neutral hydrogen in the intergalactic medium (IGM) on the spectra of high-redshift (z ~ 6) sources, using mock spectra generated from hydrodynamical...
Is there a missing galaxy problem at high redshift? (2004)
Nagamine, Kentaro, Cen, Renyue, Hernquist, Lars, Ostriker, Jeremiah P., Springel, Volker
We show that large, high-redshift (z>10) galaxies with virial temperature in excess of 10^4K may be mostly comprised of cold atomic clouds which were formerly minihalos. These clouds move at a speed...
Is There a Missing Galaxy Problem at High Redshift? (2003)
Nagamine, Kentaro, Cen, Renyue, Hernquist, Lars, Ostriker, Jeremiah P., Springel, Volker
We study the evolution of the global stellar mass density in a Lambda cold dark matter universe using two different types of hydrodynamical simulations (Eulerian TVD and SPH) and the analytical model...
Colgate, Stirling A., Cen, Renyue, Li, Hui, Currier, Nathan, Warren, Michael S.
A scenario is put forth for the formation of supermassive black holes at the centers of galaxies. It depends upon the formation of a Mestel disk with a flat rotation curve, where the mass is...
Ostriker, Jeremiah P., Nagamine, Kentaro, Cen, Renyue, Fukugita, Masataka
While second and higher order correlations of the light distribution have received extensive study, the lowest order probability distribution function (PDF) -- the probability that a unit volume of...
Galaxies Inside Stromgren Spheres of Luminous Quasars at z>6: Detection of The First Galaxies (2003)
The intrinsic Lyman-alpha emission lines of normal galaxies before reionization are much absorbed by the damping wing of the Gunn-Peterson trough, rendering their direct detection nearly impossible,...
Implications of WMAP Observations On the Population III Star Formation Processes (2003)
In an earlier paper (Cen 2003) we pointed out the strong likelihood for the universal reionization to occur twice, giving rise to a larger Thomson optical depth. Here we perform a more focused...
The Universe Was Reionized Twice (2002)
We show the universe was reionized twice, first at z~15-16 and second at z~6. Such an outcome appears inevitable, when normalizing to two well determined observational measurements, namely, the epoch...
The recent discovery of bright quasars around redshift z=6 suggests that black holes (BHs) with masses in excess of 10^9 Msun have already assembled at a very early stage in the evolution of the...
Metallicity Evolution of Damped Lyman Alpha Systems In Lambda CDM Cosmology (2002)
Cen, Renyue, Ostriker, Jeremiah P., Prochaska, Jason X., Wolfe, Arthur M.
Utilizing a new, high mass resolution hydrodynamic simulation we compute the metallicity evolution of damped Lyman alpha systems (DLAs) and find a reasonable agreement with observations. In...
Large-scale Correlation of Mass and Galaxies with the Lyman-alpha Forest Transmitted Flux (2001)
McDonald, Patrick, Miralda-Escudé, Jordi, Cen, Renyue
We present predictions of the correlation between the Lyman-alpha forest absorption in quasar spectra and the mass within \sim 5 Mpc/h (comoving) of the line of sight, using fully hydrodynamic and...
A Fast, Accurate and Robust Algorithm For Transferring Radiation in Three-Dimensional Space (2001)
We have developed an algorithm for transferring radiation in three-dimensional space. The algorithm computes radiation source and sink terms using the Fast Fourier Transform (FFT) method, based on a...
Cen, Renyue, McDonald, Patrick
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...
Revealing the Warm-Hot Intergalactic Medium with OVI Absorption (2001)
Cen, Renyue, Tripp, Todd M., Ostriker, Jeremiah P., Jenkins, Edward B.
Hydrodynamic simulations of growth of cosmic structure suggest that 30-50% of the total baryons at z=0 may be in a warm-hot intergalactic medium (WHIM) with temperatures ~10^5-10^7K. The O VI \lambda...
Mass-Temperature Relation of Galaxy Clusters: A Theoretical Study (2001)
Afshordi, Niayesh, Cen, Renyue
Combining conservation of energy throughout nearly-spherical collapse of galaxy clusters with the virial theorem, we derive the mass-temperature relation for X-ray clusters of galaxies $T=CM^{2/3}$....
Evolution of the Luminosity Function and Colors of Galaxies in a Lambda-CDM Universe (2001)
Nagamine, Kentaro, Fukugita, Masataka, Cen, Renyue, Ostriker, Jeremiah P.
The luminosity function of galaxies is derived from a cosmological hydrodynamic simulation of a Lambda cold dark matter (CDM) universe with the aid of a stellar population synthesis model. At z=0,...
Gas rich sub-galactic halos with mass Mt
Why Are There Dwarf Spheroidal Galaxies? (2000)
There appears to exist a conflict between the standard structure formation theory and the existence of the faint dwarf spheroidal galaxies in the Local Group. Theoretical considerations suggest that...
Star Formation History and Stellar Metallicity Distribution in a Cold Dark Matter Universe (2000)
Nagamine, Kentaro, Fukugita, Masataka, Cen, Renyue, Ostriker, Jeremiah P.
We study star formation history and stellar metallicity distribution in galaxies in a Lambda cold dark matter universe using a hydrodynamic cosmological simulation. Our model predicts star formation...
Metal Enrichment and Temperature of the Intergalactic Medium (2000)
Hydrodynamic simulations of Lyman alpha clouds based on ab inito cosmological models have produced results that are in broad agreement with observations. However, further analyses have revealed that,...
Cosmic Mach Number as a Function of Overdensity and Galaxy Age (2000)
Nagamine, Kentaro, Ostriker, Jeremiah P., Cen, Renyue
We carry out an extensive study of the cosmic Mach number (\mach) on scales of R=5, 10 and 20h^-1Mpc using an LCDM hydrodynamical simulation. We particularly put emphasis on the environmental...
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
Quasar Str\"omgren Spheres Before Cosmological Reionization (2000)
Ionizing sources embedded in the neutral intergalactic medium (IGM) before cosmological reionization generate discrete HII regions. We show that a sufficiently bright quasar (for example, one tenth...
McDonald, Patrick, Miralda-Escude, Jordi, Rauch, Michael, Sargent, Wallace L. W., Barlow, Tom A., Cen, Renyue
The evolution of the temperature in the intergalactic medium is related to the reionization of hydrogen and helium, and has important consequences for our understanding of the Lya forest and of...
Properties of Cosmic Shock Waves in Large Scale Structure Formation (2000)
Miniati, Francesco, Ryu, Dongsu, Kang, Hyesung, Jones, T. W., Cen, Renyue, Ostriker, Jeremiah P.
We have examined the properties of shock waves in simulations of large scale structure formation for two cosmological scenarios (a SCDM and a LCDM with Omega =1). Large-scale shocks result from...
Decaying Cold Dark Matter Model and Small-Scale Power (2000)
The canonical cosmological constant dominated cold dark matter model (LCDM) may possess too much power on small scales at z=0, manifested as central over-concentration of dark matter and...
Evolution of Lyman Break Galaxies Beyond Redshift Four (2000)
The formation rate of luminous galaxies seems to be roughly constant from z~2 to z~4 from the recent observations of Lyman break galaxies (LBGs) (Steidel et al 1999). The abundance of luminous...
Dependence of Star Formation Rate on Overdensity (1999)
Nagamine, Kentaro, Cen, Renyue, Ostriker, Jeremiah P.
We use a large-scale Lambda-CDM hydrodynamical simulation to assess the dependence of the cosmic Star Formation Rate (SFR) on overdensity of luminosity. The `morphology-density relation' is...
McDonald, Patrick, Miralda-Escude, Jordi, Rauch, Michael, Sargent, Wallace L. W., Barlow, Tom A., Cen, Renyue, ...
A sample of eight quasars observed at high resolution and signal-to-noise is used to determine the probability distribution function (PDF), the power spectrum, and the correlation function of the...
The structure of dark matter halos in hierarchical clustering theories (1999)
Subramanian, Kandaswamy, Cen, Renyue, Ostriker, Jeremiah P.
During hierarchical clustering, smaller masses generally collapse earlier than larger masses and so are denser on the average. The core of a small mass halo could be dense enough to resist disruption...
The Intergalactic Medium and Soft X-ray Background (1999)
I present an overview of some of the recent advances in our understanding of the distribution and evolution of the ordinary, baryonic matter in the universe. Two observations that strongly suggest...
A Possible Lateral Gamma-Ray Burst Jet from Supernova 1987A (1999)
There was a bright, transient companion spot to SN1987A with a projected distance of about 17 light-days, observed by optical speckle interferometry one to two months after explosion. It is shown...
An Intrinsic Smoothing Mechanism For Gamma-Ray Burst Spectra in the Fireball Model (1999)
It is shown that differential Doppler shift of different patches of the blastwave front in the fireball model at varying angles to the line of sight could provide an intrinsic smoothing mechanism for...
Cosmic Chemical Evolution (1999)
Cen, Renyue, Ostriker, Jeremiah P.
Numerical simulations of standard cosmological scenarios have now reached the degree of sophistication required to provide tentative answers to the fundamental question: Where and when were the heavy...
Time Evolution of Galaxy Formation and Bias in Cosmological Simulations (1999)
Blanton, Michael, Cen, Renyue, Ostriker, Jeremiah P., Strauss, Michael A., Tegmark, Max
The clustering of galaxies relative to the mass distribution declines with time because: first, nonlinear peaks become less rare events; second, the densest regions stop forming new galaxies because...
Nagamine, Kentaro, Cen, Renyue, Ostriker, Jeremiah P.
We compute the cosmic star formation rate (SFR) and the rest-frame comoving luminosity density in various pass-bands as a function of redshift using large-scale \Lambda-CDM hydrodynamical simulations...
Accuracy of Mesh Based Cosmological Hydrocodes: Tests and Corrections (1998)
Cen, Renyue, Ostriker, Jeremiah P.
We perform a variety of tests to determine the numerical resolution of the cosmological TVD eulerian code developed by Ryu et al (1993). Tests include 512^3 and 256^3 simulations of a Pk=k^{-1}...
Physical Bias of Galaxies From Large-Scale Hydrodynamic Simulations (1998)
Cen, Renyue, Ostriker, Jeremiah P.
We analyze a new large-scale ($100h^{-1}$Mpc) numerical hydrodynamic simulation of the popular $\Lambda$CDM cosmological model, including in our treatment dark matter, gas and star-formation, on the...
Supernovae, Pulsars and Gamma-Ray Bursts: A Unified Picture (1998)
A scenario is proposed that explains both the observed high pulsar velocities and extragalactic gamma-ray bursts (GRBs). The model involves an ultra- relativistic jet from a supernova (SN), that...
Testing Cold Dark Matter Models At Moderate to High Redshift (1998)
The COBE microwave background temperature fluctuations and the abundance of local rich clusters of galaxies provide the two most powerful constraints on cosmological models. When all variants of the...
The Physical Origin of Scale Dependent Bias in Cosmological Simulations (1998)
Blanton, Michael, Cen, Renyue, Ostriker, Jeremiah P., Strauss, Michael A.
Using large-scale hydrodynamic simulations with heuristic criteria for galaxy formation, we investigate how the galaxy field is related to the mass density and the gas temperature. We find that the...
Cen, Renyue, Ostriker, Jeremiah P.
New, high resolution, large-scale, cosmological hydrodynamic galaxy formation simulations of a standard cold dark matter model (with a cosmological constant) are utilized to predict the distribution...
Gaussian Peaks and Clusters of Galaxies (1998)
(shortened) We develop and test a method to compute mass and auto-correlation functions of rich clusters of galaxies from linear density fluctuations, based on the formalism of Gaussian peaks...
On the Cluster Sunyaev-Zel'dovich Effect and Hubble Constant (1998)
This study shows one important effect of preexistent cosmic microwave background temperature fluctuations on the determination of the Hubble constant through Sunyaev-Zel'dovich effect of clusters of...
1. PERSONNEL During the reporting year the research staff consisted of (1998)
Neta Bahcall, Renyue Cen, Bruce Draine, Edward Fitzpatrick, Jeremy Goodman, J. Richard Gott, ...
This report provides a summary and bibliography for the research activities at the Princeton University Observatory and Department of Astrophysical Sciences during the period July 1, 1997 to June 30,...
New high-resolution, large-scale cosmological hydrodynamic galaxy formation simulations of a standard cold dark matter model (with a cosmological constant) are utilized to predict the distribution of...
Determining the Amplitude of Mass Fluctuations in the Universe (1997)
Fan, Xiaohui, Bahcall, Neta A., Cen, Renyue
We present a method for determining the rms mass fluctuations on 8 h^-1 Mpc scale, sigma8. The method utilizes the rate of evolution of the abundance of rich clusters of galaxies. Using the...
On the Clustering of Lyman Alpha Clouds (1997)
Cen, Renyue, Phelps, Steven, Miralda-Escudé, Jordi, Ostriker, Jeremiah P.
We examine the correlational property of $\lya$ clouds in detail and compare it to that of mass and galaxies. We show that the correlation strength of $\lya$ clouds is somewhat weaker than that of...
A Critical Test of Topological Defect Models: Spatial Clustering of Clusters of Galaxies (1997)
Gaussian cosmological models, typified by the inflationary cold dark matter models, and non-Gaussian topological defect based cosmological models, such as the texture seeded model, differ in the...
The Galaxy Pairwise Velocity Dispersion as a Function of Local Density (1997)
Strauss, Michael A., Ostriker, Jeremiah P., Cen, Renyue
The standard method of measuring the galaxy pairwise velocity dispersion on small scales is heavily weighted by the densest regions in a way that is difficult to calibrate. We propose a new statistic...
Constraining Omega with Cluster Evolution (1997)
Bahcall, Neta A., Fan, Xiaohui, Cen, Renyue
We show that the evolution of the number density of rich clusters of galaxies breaks the degeneracy between Omega (the mass density ratio of the universe) and sigma_{8} (the normalization of the...
Cen, Renyue, Simcoe, Robert A.
This study analyzes the sizes, shapes and correlations of $\lya$ clouds produced by a hydrodynamic simulation of a spatially flat CDM universe with a non-zero cosmological constant ($\Omega_0=0.4$,...
Constraining Ω with Cluster Evolution (1997)
Neta A. Bahcall, Xiaohui Fan, Renyue Cen
We show that the evolution of the number density of rich clusters of galaxies breaks the degeneracy between\Omega (the mass density ratio of the universe) and oe 8 (the normalization of the power...
Testing Cosmological Models by Gravitational Lensing: I. Method and First Applications (1996)
Wambsganss, Joachim, Cen, Renyue, Ostriker, Jeremiah P.
Gravitational lensing directly measures mass density fluctuations along the lines of sight to very distant objects. No assumptions need to be made concerning bias, the ratio of fluctuations in galaxy...
We pay particular attention to the high end of the $\lya$ optical depth distribution of a quasar spectrum. Based on the flux distribution (Miralda-Escud\'e et al 1996), a simple yet seemingly...
We study the projection effects on various observables of clusters of galaxies at redshift near zero, including cluster richness, velocity dispersion, X-ray luminosity, three total mass estimates...
The Protogalactic Origin for Cosmic Magnetic Fields (1996)
Kulsrud, Russell M., Cen, Renyue, Ostriker, Jeremiah P., Ryu, Dongsu
It is demonstrated that strong magnetic fields are produced from a zero initial magnetic field during the pregalactic era, when galaxies are first forming. Their development proceeds in three phases....
Wambsganss, Joachim, Cen, Renyue, Xu, Guohong, Ostriker, Jeremiah P.
Weak gravitational lensing by large-scale structure affects the determination of the cosmological deceleration parameter $q_0$. We find that the lensing induced dispersions on truly standard candles...
Ostriker, Jeremiah P., Cen, Renyue
We compute, including a current state-of-the-art treatment of hydrodynamical processes, heating and cooling, a variety of cosmological models into the extreme nonlinear phase to enable comparisons...
The Lyman Alpha Forest from Gravitational Collapse in the CDM+Lambda Model (1995)
Miralda-Escude, Jordi, Cen, Renyue, Ostriker, Jeremiah P., Rauch, Michael
We model the $\lya$ forest in a spatially flat, CDM model with $\Omega=0.4$, with an Eulerian hydrodynamic simulation, and find that the intergalactic, photoionized gas collapses into sheet-like and...
Lubin, Lori M., Cen, Renyue, Bahcall, Neta A., Ostriker, Jeremiah P.
The observed baryon fraction and velocity--temperature relation in clusters of galaxies are compared with hydrodynamic simulations in two cosmological models : standard (Omega = 1) and a low-density...
Background X-ray Emission from Hot Gas in CDM and CDM+Lambda Universes: Spectral Signatures (1995)
Cen, Renyue, Kang, Hyesung, Ostriker, Jeremiah P., Ryu, Dongsu
We present a new treatment of two popular models for the growth of structure, examining the X-ray emission from hot gas with allowance for spectral line emission from various atomic species,...
Pattern in Nonlinear Gravatational Clustering: A Numerical Investigation (1995)
Padmanabhan, T., Cen, Renyue, Ostriker, Jeremiah P., Summers, F J
The nonlinear clustering of dark matter particles in an expanding universe is usually studied by N-body simulations. One can gain some insight into this complex problem if simple relations between...
Topology of Large-Scale Structure by Galaxy Type: Hydrodynamic Simulations (1995)
Gott, J. Richard, Cen, Renyue, Ostriker, Jeremiah P.
The topology of large scale structure is studied as a function of galaxy type using the genus statistic. In hydrodynamical cosmological CDM simulations, galaxies form on caustic surfaces (Zeldovich...
The Motions of Clusters and Groups of Galaxies (1994)
Bahcall, Neta A., Gramann, Mirt, Cen, Renyue
The distributions of peculiar velocities of rich clusters and of groups of galaxies are investigated for different cosmological models and are compared with observations. Four cosmological models are...
Testing Cosmogonic Models with Gravitational Lensing (1994)
Wambsganss, Joachim, Cen, Renyue, Ostriker, Jeremiah P., Turner, Edwin L.
Gravitational lensing provides a strict test of cosmogonic models. Detailed numerical propagation of light rays through a universe having a distribution of inhomogeneities derived from the standard...
Velocity Correlations of Galaxy Clusters (1994)
Cen, Renyue, Bahcall, Neta A., Gramann, Mirt
We determine the velocity correlation function, pairwise peculiar velocity difference, and root-mean-square pairwise peculiar velocity dispersion of rich clusters of galaxies, as a function of pair...
Gravitational Collapse of Small-Scale Structure as the Origin of the Lyman Alpha Forest (1994)
Cen, Renyue, Miralda-Escude, Jordi, Ostriker, Jeremiah P., Rauch, Michael
If gravitational clustering is a hierarchical process, the present large-scale structure of the galaxy distribution implies that structures on smaller scales must have formed at high redshift. We...
Probing the Large-Scale Velocity Field with Clusters of Galaxies (1994)
Bahcall, Neta A., Cen, Renyue, Gramann, Mirt
What is the role of clusters of galaxies in probing the large-scale velocity field of the universe? We investigate the distribution of peculiar velocities of clusters of galaxies in the popular...
The mass and velocity distributions in the outskirts ($0.5-3.0h^{-1}$Mpc) of clusters of galaxies are examined for a suite of cosmogonic models utilizing large-scale Particle-Mesh (PM) simulations...
The Motions of Clusters and Groups of Galaxies (1994)
Bahcall, Neta A., Gramann, Mirt, Cen, Renyue
The distributions of peculiar velocities of rich clusters and of groups of galaxies are investigated for different cosmological models and are compared with observations. Four cosmological models are...
The Correlation Function of Flux-Limited X-Ray Clusters (1994)
We show that the spatial correlation function of a flux-limited sample of X-ray selected clusters of galaxies will exhibit a correlation scale that is smaller than the correlation scale of a...
A Hydrodynamic Approach to Cosmology: The Mixed Dark Matter Cosmological Scenario (1994)
Cen, Renyue, Ostriker, Jeremiah P.
We compute the evolution of spatially flat, mixed cold and hot dark matter (``MDM") models containing both baryonic matter and two kinds of dark matter. The mean final Zeldovich-Sunyaev $y$ parameter...
Cen, Renyue, Ostriker, Jeremiah P.
A new, three-dimensional, shock capturing, TVD hydrodynamic code is utilized to determine the distribution of hot gas in a CDM$+\Lambda$ model universe. This open model succeeds in matching local...
Hot Gas in the CDM Scenario: X-Ray Clusters from a High Resolution Numerical Simulation (1994)
Kang, Hyesung, Cen, Renyue, Ostriker, Jeremiah P., Ryu, Dongsu
We exmaine the distribution of hot gas in a standard CDM model of the universe using high resolution hydrodynamic simulations. Adopting standard parameters determined from COBE and light element...
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...
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...
Confrontation of the Lauer and Postman Cluster Velocity Field with Models (1993)
Strauss, Michael, Cen, Renyue, Ostriker, Jeremiah
The large-scale bulk flow implied by the measurements of distances to brightest cluster members within 15,000 km/s by Lauer and Postman has the potential to put strong constraints on, or to even rule...
Hydrodynamic simulations of cosmology / (1991)
Thesis (Ph.D.)--Princeton University, 1991.