Peeples, Molly S., Weinberg, David H., Davé, Romeel, Fardal, Mark A., Katz, Neal
We examine the impact of gas pressure on the transverse coherence of high-redshift (2
Peeples, Molly S., Weinberg, David H., Davé, Romeel, Fardal, Mark A., Katz, Neal
In the low density intergalactic medium (IGM) that gives rise to the Lyman-alpha forest, gas temperature and density are tightly correlated. The velocity scale of thermal broadening and the Hubble...
The Nature of Sub-millimetre Galaxies in Cosmological Hydrodynamic Simulations (2009)
Davé, Romeel, Finlator, Kristian, Oppenheimer, Benjamin D., Fardal, Mark, Katz, Neal, Kereš, Dušan, ...
We study the nature of rapidly star-forming galaxies at z=2 in cosmological hydrodynamic simulations, and compare their properties to observations of sub-millimetre galaxies (SMGs). We identify...
Lyman-alpha Emission From Cosmic Structure I: Fluorescence (2009)
Kollmeier, Juna A., Zheng, Zheng, Davé, Romeel, Gould, Andrew, Katz, Neal, Miralda-Escudé, Jordi, ...
We present predictions for the fluorescent Lyman-alpha emission signature arising from photoionized, optically thick structures in Smoothed Particle Hydrodynamic (SPH) cosmological simulations of a...
Beyond the best-fit parameter: new insight on galaxy structure decomposition from GALPHAT (2009)
Yoon, Ilsang, Weinberg, Martin, Katz, Neal
We introduce a novel image decomposition package, GALPHAT, that provides robust estimates of galaxy surface brightness profiles using Bayesian Markov Chain Monte Carlo. The GALPHAT-determined...
Keres, Dusan, Katz, Neal, Dave, Romeel, Fardal, Mark, Weinberg, David H.
We compare the properties of galaxies that form in a large volume cosmological simulation without strong feedback to observations at z=0. We confirm previous findings that models without strong...
Structural Properties of Central Galaxies in Groups and Clusters (2009)
Guo, Yicheng, McIntosh, Daniel H., Mo, H. J., Katz, Neal, Weinberg, Martin, ...
Using a representative sample of 911 central galaxies (CENs) from the SDSS DR4 group catalogue, we study how the structure of the most massive members in groups and clusters depend on (1) galaxy...
The nature of red dwarf galaxies (2009)
Wang, Yu, Yang, Xiaohu, Mo, H. J., Van Den Bosch, Frank C., Katz, Neal, Pasquali, Anna, ...
Structural properties of central galaxies in groups and clusters (2009)
Guo, Yicheng, McIntosh, Daniel H., Mo, H. J., Katz, Neal, Van Den Bosch, Frank C., Weinberg, Martin, ...
The nature of red dwarf galaxies (2008)
Wang, Yu, Yang, Xiaohu, Mo, H. J., Katz, Neal, Pasquali, Anna, ...
Using dark matter halos traced by galaxy groups selected from the Sloan Digital Sky Survey Data Release 4, we find that about 1/4 of the faint galaxies ($\rmag >-17.05$, hereafter dwarfs) that are...
The dynamics of satellite disruption in cold dark matter haloes (2008)
Choi, Jun-Hwan, Weinberg, Martin D., Katz, Neal
We investigate the physical mechanisms of tidal heating and satellite disruption in cold dark matter host haloes using N-body simulations based on cosmological initial conditions. We show the...
Simha, Vimal, Weinberg, David H., Dave, Romeel, Gnedin, Oleg Y., Katz, Neal, Keres, Dusan
We examine the accretion and merger histories of central and satellite galaxies in a smoothed particle hydrodynamics (SPH) cosmological simulation that resolves galaxies down to 7e9 M[Sun]. Most...
Galaxies in a simulated $\Lambda$CDM Universe I: cold mode and hot cores (2008)
Kereš, Dušan, Katz, Neal, Fardal, Mark, Dave, Romeel, Weinberg, David H.
We study the formation of galaxies in a (50 Mpc/h)^3 cosmological simulation (2x288^3 particles), evolved using the entropy conserving SPH code Gadget-2. Most of the baryonic mass in galaxies of all...
McIntosh, Daniel H., Guo, Yicheng, Hertzberg, Jen, Katz, Neal, Mo, H. J., Van Den Bosch, Frank C., ...
We investigate the incidence of major mergers creating massive (Mstar > 1011Msolar) galaxies in present-day (z
Photoionization, Numerical Resolution, And Galaxy Formation (2007)
David Weinberg Ohio, David H. Weinberg, Lars Hernquist, Neal Katz
Using cosmological simulations that incorporate gas dynamics and gravitational forces, we investigate the influence of photoionization by an ultraviolet radiation background on the formation of...
Simulating Cosmic Structure Formation (2007)
David Weinberg, Neal Katz, Lars Hernquist
. We describe cosmological simulation techniques and their application to studies of cosmic structure formation, with particular attention to recent hydrodynamic simulations of structure in the high...
Testing Cosmological Models Against The Abundance Of Damped Lyman-Alpha Absorbers (2007)
Jeffrey Gardner, Neal Katz, David H. Weinberg, Lars Hernquist
We calculate the number of damped Lyff absorbers expected in various popular cosmological models as a function of redshift and compare our predictions with observed abundances. The Press-Schechter...
The Population Of Damped Lyman-Alpha And Lyman Limit Systems In The Cold Dark Matter Model (2007)
Jeffrey Gardner, Neal Katz, Lars Hernquist, David H. Weinberg
Lyman limit and damped Lyff absorption systems probe the distribution of collapsed, cold gas at high redshift. Numerical simulations that incorporate gravity and gas dynamics can predict the...
McIntosh, Daniel H., Guo, Yicheng, Hertzberg, Jen, Katz, Neal, Mo, H. J., ...
We investigate the incidence of major mergers creating >10e11 Msun galaxies in present-day groups and clusters more massive than 2.5e13 Msun. We identify 38 pairs of massive galaxies with mutual...
The dynamics of tidal tails from massive satellites (2007)
Choi, Jun-Hwan, Weinberg, Martin D., Katz, Neal
(Abbreviated) We investigate the dynamical mechanisms responsible for producing tidal tails from dwarf satellites using N-body simulations. We identify two important dynamical co-conspirators: 1) the...
Cattaneo, Andrea, Blaizot, Jérémy, Weinberg, David H., Keres, Dusan, Colombi, Stephane, Davé, Romeel, ...
Cattaneo, Andrea, Blaizot, Jeremy, Weinberg, David H., Colombi, Stephane, Dave, Romeel, Devriendt, Julien, ...
We compare the galaxy population of an SPH simulation to those predicted by the GalICS semi-analytic model and a stripped down version without supernova and AGN feedback. The SPH simulation and the...
On the Evolutionary History of Stars and their Fossil Mass and Light (2006)
Fardal, Mark A., Katz, Neal, Weinberg, David H., Dav'e, Romeel
The total extragalactic background radiation can be an important test of the global star formation history (SFH). Using direct observational estimates of the SFH, along with standard assumptions...
Baryon Dynamics, Dark Matter Substructure, and Galaxies (2006)
Weinberg, David H., Colombi, Stephane, Davé, Romeel, Katz, Neal
By comparing a collisionless cosmological N-body simulation (DM) to an SPH simulation with the same initial conditions, we investigate the correspondence between the dark matter subhalos produced by...
Stinson, Greg, Seth, Anil, Katz, Neal, Wadsley, James, Governato, Fabio, Quinn, Tom
We present an analysis of star formation and feedback recipes appropriate for galactic smoothed particle hydrodynamics simulations. Using an isolated Milky Way-like galaxy, we constrain these recipes...
The Bar-Halo Interaction - II. Secular evolution and the religion of N-body simulations (2006)
Weinberg, Martin D., Katz, Neal
This paper explores resonance-driven secular evolution between a bar and dark-matter halo using N-body simulations. We make direct comparisons to our analytic theory (Weinberg & Katz 2005) to...
Nature and completeness of galaxies detected in the Two Micron All Sky Survey (2006)
McIntosh, Daniel H., Bell, Eric F., Weinberg, Martin D., Katz, Neal
The Two Micron All Sky Survey (2MASS) provides the most comprehensive data set of near-infrared galaxy properties. We cross correlate the well-defined and highly complete spectroscopic selection of...
Nature and completeness of galaxies detected in the Two Micron All Sky Survey (2005)
McIntosh, Daniel H., Bell, Eric F., Weinberg, Martin D., Katz, Neal
We cross correlate the well-defined and very complete spectroscopic Main Galaxy Sample (MGS) of 156,000 bright (r16 galaxies found in the XSC are over-representative in red early types and...
From Galaxy-Galaxy Lensing to Cosmological Parameters (2005)
Yoo, Jaiyul, Tinker, Jeremy L., Weinberg, David H., Zheng, Zheng, Katz, Neal, Davé, Romeel
Galaxy-galaxy lensing measures the mean excess surface density DS(r) around a sample of lensing galaxies. We develop a method for combining DS(r) with the galaxy correlation function xi_gg(r) to...
Building Galaxies with Simulations (2005)
Davé, Romeel, Finlator, Kristian, Hernquist, Lars, Katz, Neal, Kereš, Dušan, Papovich, Casey, ...
We present an overview of some of the issues surrounding current models of galaxy formation, highlighting recent insights obtained from cosmological hydrodynamic simulations. Detailed examination of...
Galaxy Merger Statistics and Inferred Bulge-to-Disk Ratios in Cosmological SPH Simulations (2005)
Maller, Ariyeh, Katz, Neal, Keres, Dusan, Dave, Romeel, Weinberg, David H.
We construct merger trees for galaxies identified in a cosmological hydrodynamical simulation and use them to characterize predicted merger rates as a function of redshift, galaxy mass, and merger...
Probing Galaxy Formation with He II Cooling Lines (2005)
Yang, Yujin, Zabludoff, Ann I., Davé, Romeel, Eisenstein, Daniel J., Pinto, Philip A., Katz, Neal, ...
Using high resolution cosmological simulations, we study hydrogen and helium gravitational cooling radiation. We focus on the HeII cooling lines, which arise from gas with a different temperature...
On the origin of cold dark matter halo density profiles (2005)
Lu, Yu, Mo, H. J., Katz, Neal, Weinberg, Martin D.
N-body simulations predict that CDM halo-assembly occurs in two phases: 1) a fast accretion phase with a rapidly deepening potential well; and 2) a slow accretion phase characterised by a gentle...
The Bar--Halo Interaction--I. From Fundamental Dynamics to Revised N-body Requirements (2005)
Weinberg, Martin D., Katz, Neal
Only through resonances can non-axisymmetric features such as spiral arms and bars exert torques over large scales and change the overall structure of a near-equilibrium galaxy. We describe the...
Preheating by Previrialization and its Impact on Galaxy Formation (2005)
Mo, H. J., Yang, Xiaohu, Katz, Neal
We use recent observations of the HI-mass function to constrain galaxy formation. The data conflicts with the standard model where most of the gas in a low-mass dark matter halo is assumed to settle...
Lyman Alpha Flux Power Spectrum and Its Covariance (2005)
Zhan, Hu, Dave, Romeel, Eisenstein, Daniel, Katz, Neal
We analyze the flux power spectrum and its covariance using simulated Lyman alpha forests. We find that pseudo-hydro techniques are good approximations of hydrodynamical simulations at high redshift....
Bouche, Nicolas, Gardner, Jeffrey P., Weinberg, David H., Katz, Neal, Dave, Romeel, Lowenthal, James D.
[Abridged] We test the reliability of a method to measure the mean halo mass of Damped Ly-alpha absorbers (DLAs). The method is based on measuring the ratio of the cross-correlation between DLAs and...
Bouché, Nicolas, Gardner, Jeffrey P., Katz, Neal, Weinberg, David H., Davé, Romeel, Lowenthal, James D.
Zheng, Zheng, Berlind, Andreas A., Weinberg, David H., Benson, Andrew J., Baugh, Carlton M., Cole, Shaun, ...
The halo occupation distribution (HOD) describes the relation between galaxies and dark matter at the level of individual dark matter halos. The properties of galaxies residing at the centers of...
How Do Galaxies Get Their Gas? (2004)
Keres, Dusan, Katz, Neal, Weinberg, David H., Dave, Romeel
We examine the temperature history of gas accreted by forming galaxies in SPH simulations. About half the gas shock heats to roughly the virial temperature of the galaxy potential well before...
Interpreting the Relationship Between Galaxy Luminosity, Color and Environment (2004)
Berlind, Andreas A., Blanton, Michael R., Hogg, David W., Weinberg, David H., Davé, Romeel, Eisenstein, Daniel J., ...
We study the relationship between galaxy luminosity, color, and environment in a cosmological simulation of galaxy formation. We compare the predicted relationship with that found for SDSS galaxies...
Bar-Induced Evolution of Dark Matter Cusps (2003)
Holley-Bockelmann, Kelly, Weinberg, Martin, Katz, Neal
The evolution of a stellar bar transforms not only the galactic disk, but also the host dark matter halo. We present high resolution, fully self-consistent N-body simulations that clearly demonstrate...
Maller, Ariyeh H., McIntosh, Daniel H., Katz, Neal, Weinberg, Martin D.
We calculate the angular correlation function of galaxies in the Two Micron All Sky Survey. We minimize the possible contamination by stars, dust, seeing and sky brightness by studying their cross...
The Clustering Dipole of the Local Universe from the Two Micron All Sky Survey (2003)
Maller, Ariyeh H., McIntosh, Daniel H., Katz, Neal, Weinberg, Martin D.
The unprecedented sky coverage and photometric uniformity of the Two Micron All Sky Survey (2MASS) provides a rich resource for investigating the galaxies populating the local Universe. A full...
On the Relationship between Cooling Flows and Bubbles (2003)
McCarthy, Ian G., Babul, Arif, Katz, Neal, Balogh, Michael L.
A common feature of the X-ray bubbles observed in Chandra images of some "cooling flow" clusters is that they appear to be surrounded by bright, cool shells. Temperature maps of a few nearby luminous...
Bell, Eric F., McIntosh, Daniel H., Katz, Neal, Weinberg, Martin D.
We use a large sample of galaxies from the Two Micron All Sky Survey (2MASS) and the Sloan Digital Sky Survey (SDSS) to calculate galaxy luminosity and stellar mass functions in the local Universe....
A First Estimate of the Baryonic Mass Function of Galaxies (2003)
Bell, Eric F., McIntosh, Daniel H., Katz, Neal, Weinberg, Martin D.
We estimate the baryonic (stellar+cold gas) mass function of galaxies in the local Universe by assigning a complete sample of Two Micron All Sky Survey and Sloan Digital Sky Survey galaxies a gas...
The Lyman-alpha Forest as a Cosmological Tool (2003)
Weinberg, David H., Dav'e, Romeel, Katz, Neal, Kollmeier, Juna A.
We review recent developments in the theory of the Lyman-alpha forest and their implications for the role of the forest as a test of cosmological models. Simulations predict a relatively tight...
Bell, Eric F., McIntosh, Daniel H., Katz, Neal, Weinberg, Martin D.
We use a large sample of galaxies from the Two Micron All Sky Survey (2MASS) and the Sloan Digital Sky Survey (SDSS) to calculate galaxy luminosity and stellar mass functions in the local universe....
A first estimate of the baryonic mass function of galaxies (2003)
Bell, Eric F., McIntosh, Daniel H., Katz, Neal, Weinberg, Martin D.
We estimate the baryonic (stellar+cold gas) mass function of galaxies in the local universe by assigning a complete sample of Two Micron All Sky Survey and Sloan Digital Sky Survey galaxies a gas...
Lyman Alpha Absorber Correlations and the Bias of the Lyman Alpha Forest (2002)
Davé, Romeel, Katz, Neal, Weinberg, David H.
Lyman alpha absorber correlations contain information about the underlying density distribution associated with a particular class of absorbers. As such, they provide an opportunity to independently...
The Galaxy Proximity Effect in the Lyman-alpha Forest (2002)
Kollmeier, Juna A., Weinberg, David H., Dave', Romeel, Katz, Neal
Hydrodynamic cosmological simulations predict that the average opacity of the Ly-alpha forest should increase in the neighborhood of galaxies because galaxies form in dense environments. Recent...
Galaxy Clustering and Galaxy Bias in a Lambda-CDM Universe (2002)
Weinberg, David H., Dav'e, Romeel, Katz, Neal, Hernquist, Lars
We investigate galaxy clustering and galaxy-mass correlations in the LCDM cosmological model using a large volume SPH simulation. For the most part, the predicted biases between galaxies and dark...
The Halo Occupation Distribution and the Physics of Galaxy Formation (2002)
Berlind, Andreas A., Weinberg, David H., Benson, Andrew J., Baugh, Carlton M., Cole, Shaun, Davé, Romeel, ...
The halo occupation distribution (HOD) describes the bias between galaxies and dark matter by specifying (a) the probability P(N|M) that a halo of virial mass M contains N galaxies of a particular...
Lyman Break Galaxies and the Lyman-alpha Forest (2002)
Kollmeier, Juna A., Weinberg, David H., Dave', Romeel, Katz, Neal
We use hydrodynamic simulations to predict correlations between Lya forest absorption and galaxies at redshift z~3. The probability distribution function (PDF) of Lya flux decrements shifts...
How Do Galaxies Get Their Gas? (2002)
Katz, Neal, Keres, Dusan, Dave, Romeel, Weinberg, David H.
Not the way one might have thought. In hydrodynamic simulations of galaxy formation, some gas follows the traditionally envisioned route, shock heating to the halo virial temperature before cooling...
Structure of Bright 2MASS Galaxies: 2D Fits to the Ks-band Surface Brightness Profiles (2002)
McIntosh, Daniel H., Maller, Ari H., Katz, Neal, Weinberg, Martin D.
The unprecedented sky coverage and photometric uniformity of the Two Micron All Sky Survey (2MASS) provides a rich resource for obtaining a detailed understanding of the galaxies populating our local...
X-Ray Scaling Relations of Galaxy Groups in a Hydrodynamic Cosmological Simulation (2002)
Davé, Romeel, Katz, Neal, Weinberg, David H.
We examine the scalings of X-ray luminosity, temperature, and dark matter or galaxy velocity dispersion for galaxy groups in an LCDM cosmological simulation, which incorporates gravity, gas dynamics,...
Chen, Xuelei, Weinberg, David H., Katz, Neal, Dave', Romeel
Using a hydrodynamic simulation of a LCDM universe, we investigate the "X-ray forest" absorption imprinted on the spectra of background quasars by the intervening intergalactic medium (IGM). In...
Bar-driven dark halo evolution: a resolution of the cusp--core controversy (2001)
Weinberg, Martin D., Katz, Neal
Simulations predict that the dark matter halos of galaxies should have central cusps, while those inferred from observed galaxies do not have cusps. We demonstrate, using both linear perturbation...
Group Scaling Relations From a Cosmological Hydrodynamic Simulation: No Pre-heating Required? (2001)
Davé, Romeel, Katz, Neal, Hernquist, Lars, Weinberg, David
We investigate the X-ray vs. optical scaling relations of poor groups to small clusters (sigma~100-700 km/s) identified in a cosmological hydrodynamic simulation of a Lambda-CDM universe, with...
Sub-mm Galaxies in Cosmological Simulations (2001)
Fardal, Mark A., Katz, Neal, Weinberg, David H., Davé, Romeel, Hernquist, Lars
We study the predicted sub-mm emission from massive galaxies in a Lambda-CDM universe, using hydrodynamic cosmological simulations. Assuming that most of the emission from newly formed stars is...
The Infuence of Omega_baryon on High-Redshift Structure (2001)
Gardner, Jeffrey P., Katz, Neal, Hernquist, Lars, Weinberg, David H.
We analyze high-redshift structure in three hydrodynamic simulations that have identical initial conditions and cosmological parameters and differ only in the value of the baryon density parameter,...
The growth of galaxies in cosmological simulations of structure formation (2001)
Murali, Chigurupati, Katz, Neal, Hernquist, Lars, Weinberg, David H., Dave, Romeel
We use hydrodynamic simulations to examine how the baryonic components of galaxies are assembled, focusing on the relative importance of mergers and smooth accretion in the formation of ~L_* systems....
Metal Enrichment of the Intergalactic Medium in Cosmological Simulations (2001)
Aguirre, Anthony, Hernquist, Lars, Schaye, Joop, Katz, Neal, Weinberg, David H., Gardner, Jeffrey
Observations have established that the diffuse intergalactic medium (IGM) at z ~ 3 is enriched to ~0.1-1% solar metallicity and that the hot gas in large clusters of galaxies (ICM) is enriched to...
Towards a Precise Measurement of Matter Clustering: Lyman-alpha Forest Data at Redshifts 2-4 (2000)
Croft, Rupert A. C., Weinberg, David H., Bolte, Mike, Burles, Scott, Hernquist, Lars, Katz, Neal, ...
We measure the filling factor, correlation function, and power spectrum of transmitted flux in a large sample of Lya forest spectra, comprised of 30 Keck HIRES spectra and 23 Keck LRIS spectra. We...
Hydrodynamic Simulation of the Cosmological X-ray Background (2000)
Croft, Rupert A. C., Di Matteo, Tiziana, Dav'e, Romeel, Hernquist, Lars, Katz, Neal, Fardal, Mark A., ...
(Abridged) We use a hydrodynamic simulation of a LambdaCDM model to predict the extragalactic X-ray background (XRB), focussing on emission from the intergalactic medium (IGM). We also include X-rays...
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
Cooling Radiation and the Lyman-alpha Luminosity of Forming Galaxies (2000)
Fardal, Mark A., Katz, Neal, Gardner, Jeffrey P., Hernquist, Lars, Weinberg, David H., Davé, Romeel
We examine the cooling radiation from forming galaxies in hydrodynamic simulations of the LCDM model (cold dark matter with a cosmological constant), focusing on the Ly-alpha line luminosities of...
Enrichment of the Intergalactic Medium by Radiation Pressure Driven Dust Efflux (2000)
Aguirre, Anthony, Hernquist, Lars, Katz, Neal, Gardner, Jeffrey, Weinberg, David
The presence of metals in hot cluster gas and in Ly-alpha absorbers, as well as the mass-metallicity relation of observed galaxies, suggest that galaxies lose a significant fraction of their metals...
Metal Enrichment of the Intergalactic Medium at z=3 by Galactic Winds (2000)
Aguirre, Anthony, Hernquist, Lars, Schaye, Joop, Weinberg, David, Katz, Neal, Gardner, Jeffrey
Studies of quasar absorption lines reveal that the low density intergalactic medium at z ~ 3 is enriched to 0.001-0.01 solar metallicity. This enrichment may have occurred in an early generation of...
High-Redshift Galaxies in Cold Dark Matter Models (2000)
Weinberg, David H., Hernquist, Lars, Katz, Neal
We use hydrodynamic cosmological simulations to predict the star formation properties of high-redshift galaxies (z=2-6) in five variants of the inflationary cold dark matter scenario, paying...
Simulating the effects of intergalactic grey dust (2000)
Croft, Rupert A. C., Dave', Romeel, Hernquist, Lars, Katz, Neal
Using a high-resolution cosmological hydrodynamic simulation, we present a method to constrain extinction due to intergalactic grey dust based on the observed magnitudes of distant Type IA...
Phillips, John, Weinberg, David H., Croft, Rupert A. C., Hernquist, Lars, Katz, Neal, Pettini, Max
We combine COBE-DMR measurements of cosmic microwave background anisotropy with a recent measurement of the mass power spectrum at redshift z=2.5 from Lya forest data to derive constraints on...
Gardner, Jeffrey P., Katz, Neal, Hernquist, Lars, Weinberg, David H.
We use hydrodynamic cosmological simulations to study damped Lyman-alpha (DLA) and Lyman limit (LL) absorption at redshifts z=2-4 in five variants of the cold dark matter scenario. Our standard...
The Nature of Lyman Break Galaxies in Cosmological Hydrodynamic Simulations (1999)
Davé, Romeel, Gardner, Jeffrey P., Hernquist, Lars, Katz, Neal, Weinberg, David H.
What type of objects are being detected as $z\sim 3$ "Lyman break galaxies"? Are they predominantly the most massive galaxies at that epoch, or are many of them smaller galaxies undergoing a...
Evolution of Clustering and Bias in a Lambda-CDM Universe (1999)
Davé, Romeel, Hernquist, Lars, Katz, Neal, Weinberg, David H.
We determine the evolution from $z=3\to 0$ of the galaxy and mass correlation functions and bias factor in a $50h^{-1}$Mpc $\Lambda$CDM hydrodynamic simulation with $10h^{-1}$kpc resolution. The mass...
Theoretical Modeling of the High Redshift Galaxy Population (1999)
Weinberg, David H., Dave', Romeel, Gardner, Jeffrey P., Hernquist, Lars, Katz, Neal
We review theoretical approaches to the study of galaxy formation, with emphasis on the role of hydrodynamic simulations in modeling the high redshift galaxy population. We present new predictions...
Cosmology with the Lyman-alpha Forest (1998)
Weinberg, David H., Burles, Scott, Croft, Rupert A. C., Dave', Romeel, Gomez, Gilberto, Hernquist, Lars, ...
We outline the physical picture of the high-redshift Ly-alpha forest that has emerged from cosmological simulations, describe statistical characteristics of the forest that can be used to test...
Weinberg, David H., Croft, Rupert A. C., Hernquist, Lars, Katz, Neal, Pettinini, Max
We estimate the value of the matter density parameter \Omega_0 by combining constraints from the galaxy cluster mass function with Croft et al.'s recent measurement of the mass power spectrum, P(k),...
Croft, Rupert A. C., Weinberg, David H., Pettini, Max, Hernquist, Lars, Katz, Neal
We measure the linear power spectrum of mass density fluctuations at redshift z=2.5 from the \lya forest absorption in a sample of 19 QSO spectra, using the method introduced by Croft et al. (1998)....
The Low Redshift Lyman Alpha Forest in Cold Dark Matter Cosmologies (1998)
Dave', Romeel, Hernquist, Lars, Katz, Neal, Weinberg, David
We study the physical origin of the low-redshift Lyman alpha forest in hydrodynamic simulations of four CDM cosmologies. Our main conclusions are insensitive to the cosmological model but depend on...
The Clustering of High Redshift Galaxies in the Cold Dark Matter Scenario (1998)
Katz, Neal, Hernquist, Lars, Weinberg, David H.
We investigate the clustering of high redshift galaxies in five variants of the cold dark matter (CDM) scenario, using hydrodynamic cosmological simulations that resolve the formation of systems with...
Constraining the Metallicity of the Low Density Lyman-alpha Forest Using OVI Absorption (1998)
Davé, Romeel, Hellsten, Uffe, Hernquist, Lars, Katz, Neal, Weinberg, David
We search for OVI absorption in a Keck HIRES spectrum of the z=3.62 quasar Q1422+231. Comparison of CIV measurements to cosmological simulations shows that \lya forest absorbers with N_HI > 10^{14.5}...
Cosmology from the structure of the Lyman-alpha forest (1998)
Croft, Rupert, Weinberg, David, Katz, Neal, Hernquist, Lars
A convincing physical picture for the Lyman-alpha forest has emerged from simulations and related semi-analytic studies of structure formation models. Observations can be be used in the context of...
Simulating Gas at High Redshift (1998)
Katz, Neal, Hernquist, Lars, Weinberg, David H.
We discuss simulations of gas at high redshift. We briefly review the methods used and the results for quasar absorption lines. We present gas mass functions and galaxy correlation functions for 5...
Time stepping N-body simulations (1997)
Quinn, Thomas, Katz, Neal, Stadel, Joachim, Lake, George
Leapfrog integration has been the method of choice in N-body simulations owing to its low computational cost for a symplectic integrator with second order accuracy. We introduce a new leapfrog...
Hubble Flow Broadening of the Lyman-alpha Forest and its Implications (1997)
Weinberg, David H., Hernquist, Lars, Katz, Neal, Croft, Rupert, Miralda-Escudé, Jordi
Lyman-alpha forest lines in QSO spectra have typical widths of 20-50 km/s. Low column density absorbers in cosmological simulations are large, diffuse structures, and the Hubble flow across the...
Metal Lines in Cosmological Models of Lyman-Alpha Absorbers (1997)
Hellsten, Uffe, Hernquist, Lars, Katz, Neal, Weinberg, David
The metal absorption lines found in association with \lya absorbers of moderate to high HI column density contain valuable information about the metallicity and ionization conditions within the...
Simulating Cosmic Structure Formation (1997)
Weinberg, David H., Katz, Neal, Hernquist, Lars
We describe cosmological simulation techniques and their application to studies of cosmic structure formation, with particular attention to recent hydrodynamic simulations of structure in the high...
The Observability of Metal Lines Associated with the Lyman-alpha Forest (1997)
Hellsten, Uffe, Hernquist, Lars, Katz, Neal, Weinberg, David
We develop a prescription for characterizing the strengths of metal lines associated with Lyman-alpha forest absorbers (LYFAs) of a given neutral hydrogen column density N_HI and metallicity [Fe/H]....
Croft, Rupert A. C., Weinberg, David H., Katz, Neal, Hernquist, Lars
We present a method to recover the shape and amplitude of the power spectrum of mass fluctuations, P(k), from observations of the high redshift \lya forest. The method is motivated by the physical...
Cosmological Constraints from High-Redshift Damped Lyman-Alpha Systems (1997)
Ma, Chung-Pei, Bertschinger, Edmund, Hernquist, Lars, Weinberg, David H., Katz, Neal
Any viable cosmological model must produce enough structure at early epochs to explain the amount of gas associated with high-redshift damped Ly$\alpha$ systems. We study the evolution of damped...
Testing Cosmological Models Against the Abundance of Damped Lyman-Alpha Absorbers (1997)
Gardner, Jeffrey P., Katz, Neal, Weinberg, David H., Hernquist, Lars
We calculate the number of damped Lyman-alpha absorbers expected in various popular cosmological models as a function of redshift and compare our predictions with observed abundances. The...
Cosmological Simulations with Scale-Free Initial Conditions I: Adiabatic Hydrodynamics (1997)
Owen, J. Michael, Weinberg, David H., Evrard, August E., Hernquist, Lars, Katz, Neal
We analyze hierarchical structure formation based on scale-free initial conditions in an Einstein-de Sitter universe, including a baryonic component. We present three independent, smoothed particle...
Morphological Transformation from Galaxy Harassment (1997)
Moore, Ben, Lake, George, Katz, Neal
Galaxy morphologies in clusters have undergone a remarkable transition over the past several billion years. Distant clusters at $z \sim 0.4$ are filled with small spiral galaxies, many of which are...
The Formation of Quasars in Low Luminosity Hosts via Galaxy Harassment (1997)
Lake, George, Katz, Neal, Moore, Ben
We have simulated disk galaxies undergoing continual bombardment by other galaxies in a rich cluster. "Galaxy harassment" leads to dramatic evolution of smaller disk galaxies and provides an...
Croft, Rupert A. C., Weinberg, David H., Hernquist, Lars, Katz, Neal
In gravitational instability models, \lya absorption arises from a continuous fluctuating medium, so that spectra provide a non-linear one-dimensional ``map'' of the underlying density field. We...
Metal Lines Associated with Lyman Alpha Absorbers: A Comparison of Theory and Observations (1997)
Hellsten, Uffe, Dave, Romeel, Hernquist, Lars, Weinberg, David H., Katz, Neal
We study metal line absorption of CIV, CII, SiIV, and NV at redshifts z=3.5 to z=2 within the framework of a cosmological model for the Lyman alpha forest, comparing the results of numerical...
A Lower Bound on the Cosmic Baryon Density (1997)
Weinberg, David H., Miralda-Escude, Jordi, Hernquist, Lars, Katz, Neal
We derive analytic lower bounds on the cosmic baryon density by requiring that the high-redshift IGM contain enough neutral hydrogen to produce the observed \lya absorption in quasar spectra. The key...
Intergalactic Helium Absorption in Cold Dark Matter Models (1996)
Croft, Rupert A. C., Weinberg, David H., Katz, Neal, Hernquist, Lars
Observations from the HUT and the HST have recently detected HeII absorption along the lines of sight to two high redshift quasars. We use cosmological simulations with gas dynamics to investigate...
Voigt-Profile Analysis of the Lyman-alpha Forest in a Cold Dark Matter Universe (1996)
Davé, Romeel, Hernquist, Lars, Weinberg, David, Katz, Neal
We use an automated Voigt-profile fitting procedure to extract statistical properties of the Ly$\alpha$ forest in a numerical simulation of an $\Omega=1$, cold dark matter (CDM) universe. Our...
The Population of Damped Lyman-alpha and Lyman Limit Systems in the Cold Dark Matter Model (1996)
Gardner, Jeffrey P., Katz, Neal, Hernquist, Lars, Weinberg, David H.
Lyman limit and damped Lyman-alpha absorption systems probe the distribution of collapsed, cold gas at high redshift. Numerical simulations that incorporate gravity and gas dynamics can predict the...
Davé, Romeel, Hernquist, Lars, Weinberg, David H., Katz, Neal
We use an automated Voigt-profile fitting procedure to extract statistical properties of the Ly$\alpha$ forest in a numerical simulation of an $\Omega=1$, cold dark matter (CDM) universe. Our...
Photoionization, Numerical Resolution, and Galaxy Formation (1996)
Weinberg, David H., Hernquist, Lars, Katz, Neal
Using cosmological simulations that incorporate gas dynamics and gravitational forces, we investigate the influence of photoionization by a UV radiation background on the formation of galaxies. In...
Small Scale Structure and High Redshift HI (1995)
Weinberg, David H., Hernquist, Lars, Katz, Neal, Miralda-Escude, Jordi
Cosmological simulations with gas dynamics suggest that the Lyman-alpha forest is produced mainly by "small scale structure" --- filaments and sheets that are the high redshift analog of today's...
Galaxy Harassment and the Evolution of Clusters of Galaxies (1995)
Moore, Ben, Katz, Neal, Lake, George, Dressler, Alan, Oemler, Augustus
Disturbed spiral galaxies with high rates of star formation pervaded clusters of galaxies just a few billion years ago, but nearby clusters exclude spirals in favor of ellipticals. ``Galaxy...
Photoionization and the Formation of Dwarf Galaxies (1995)
Quinn, Thomas, Katz, Neal, Efstathiou, George
It has been argued that a UV photoionizing background radiation field suppresses the formation of dwarf galaxies, and may even inhibit the formation of larger galaxies. In order to test this, we...
The Lyman-alpha Forest in the Cold Dark Matter Model (1995)
Hernquist, Lars, Katz, Neal, Weinberg, David H., Miralda-Escude, Jordi
Cosmological simulations with gas provide a detailed description of the intergalactic medium, making possible predictions of neutral hydrogen absorption in the spectra of background QSOs. We present...
Damped Lyman-alpha and Lyman Limit Absorbers in the Cold Dark Matter Model (1995)
Katz, Neal, Weinberg, David H., Hernquist, Lars, Miralda-Escude, Jordi
We study the formation of damped \lya and Lyman limit absorbers in a hierarchical clustering scenario using a gas dynamical simulation of an $\Omega = 1$, cold dark matter universe. In the...
Cosmological Simulations with TreeSPH (1995)
Katz, Neal, Weinberg, David H., Hernquist, Lars
We describe numerical methods for incorporating gas dynamics into cosmological simulations and present illustrative applications to the cold dark matter (CDM) scenario. Our evolution code, a version...
On the Destruction and Over-Merging of Dark Halos in Dissipationless N-body Simulations (1995)
Moore, Ben, Katz, Neal, Lake, George
N-body simulations that follow only a collisionless dark matter component have failed to produce galaxy halos or substructure within dense environments. We investigate the `over-merging' problem...
Physically Detached "Compact Groups" (1994)
Hernquist, Lars, Katz, Neal, Weinberg, David
A small fraction of galaxies appear to reside in dense compact groups, whose inferred crossing times are much shorter than a Hubble time. These short crossing times have led to considerable...