The Cosmic Near Infrared Background II: Fluctuations (2009)
Fernandez, Elizabeth R., Komatsu, Eiichiro, Iliev, Ilian T., Shapiro, Paul R.
The Near Infrared Background (NIRB) is one of a few methods that can be used to observe the redshifted light from early stars at a redshift of six and above. Fluctuations of the NIRB can provide...
Cosmological Radiative Transfer Comparison Project II: The Radiation-Hydrodynamic Tests (2009)
Iliev, Ilian T., Whalen, Daniel, Mellema, Garrelt, Ahn, Kyungjin, Baek, Sunghye, Gnedin, Nickolay Y., ...
The development of radiation hydrodynamical methods that are able to follow gas dynamics and radiative transfer self-consistently is key to the solution of many problems in numerical astrophysics....
The Impact of Mergers on the Survival and Abundance of Disk-Dominated Galaxies (2009)
Koda, Jun, Milosavljevic, Milos, Shapiro, Paul R.
We study the formation of disk-dominated galaxies in a LCDM universe. Their existence is considered to be a challenge for the LCDM cosmology, because galaxy mergers isotropize stellar disks and...
Ahn, Kyungjin, Shapiro, Paul R., Iliev, Ilian T., Mellema, Garrelt, Pen, Ue-Li
The first, self-consistent calculations are presented of the cosmological, H2-dissociating UV background produced during the epoch of reionization by the sources of reionization. Large-scale...
The Inhomogeneous Background of H2 Dissociating Radiation During Cosmic Reionization (2008)
Ahn, Kyungjin, Shapiro, Paul R., Iliev, Ilian T., Mellema, Garrelt, Pen, Ue-Li
The first, self-consistent calculations of the cosmological H_2 dissociating UV background produced during the epoch of reionization (EOR) by the sources of reionization are presented. Large-scale...
The Theory and Simulation of the 21-cm Background from the Epoch of Reionization (2008)
Shapiro, Paul R., Iliev, Ilian T., Mellema, Garrelt, Pen, Ue-Li, Merz, Hugh
The redshifted 21-cm line of distant neutral H atoms provides a probe of the cosmic ``dark ages'' and the epoch of reionization (``EOR'') which ended them. The radio continuum produced by this...
Simulating Cosmic Reionization (2008)
Iliev, Ilian T., Shapiro, Paul R., Mellema, Garrelt, Merz, Hugh, Pen, Ue-Li
The Cosmic Dark Ages and the Epoch of Reionization constitute a crucial missing link in our understanding of the evolution of the intergalactic medium and the formation and evolution of galaxies. Due...
Current models of the observable consequences of cosmic reionization and their detectability (2008)
Iliev, Ilian T., Mellema, Garrelt, Pen, Ue-Li, Bond, Richard J., Shapiro, Paul R.
A number of large current experiments aim to detect the signatures of the cosmic reionization at redshifts z > 6. Their success depends crucially on understanding the character of the reionization...
The Cluster-Merger Shock in 1E 0657-56 (2008)
Koda, Jun, Milosavljevic, Milos, Shapiro, Paul R., Nagai, Daisuke, Nakar, Ehud
The merging galaxy cluster 1E 0657-56, known as the "bullet cluster," is one of the hottest clusters known. The X-ray emitting plasma exhibits bow-shock-like temperature and density jumps. The...
Iliev, Ilian T., Mellema, Garrelt, Pen, Ue-Li, Shapiro, Paul R.
Direct detection of the Dark Ages and the Epoch of Reionization (EOR) is among the main scientific objectives of all current and future low-frequency radio facilities. In this paper we summarize and...
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 effect of minihaloes on cosmic reionization (2007)
Ciardi, Benedetta, Scannapieco, Evan, Stoehr, Felix, Ferrara, Andrea, Iliev, Ilian T., Shapiro, Paul R.
One of the most debated issues in the theoretical modeling of cosmic reionization is the impact of small-mass gravitationally-bound structures. We carry out the first numerical investigation of the...
REIONIZATION OF THE UNIVERSE AND THE PHOTOEVAPORATION OF COSMOLOGICAL MINIHALOS (2007)
Paul R. Shapiro, Alejandro C. Raga
Las primeras fuentes de radiacion ionizante que se condensaron del IGM generaron frentes de ionizacion en sus alrededores, que iluminaron a otros objetos condensados y los fotoevaporaron. Mostramos...
RevMexAA (Serie de Conferencias), 10, 101--108 (2001) (2007)
Explosions During Galaxy, Hugo Martel, Paul R. Shapiro
As an idealized model of the e#ects of energy release by supernovae during galaxy formation, we consider an explosion at the center of a halo which forms at the intersection of filaments in the plane...
REIONIZATION OF THE UNIVERSE AND THE PHOTOEVAPORATION OF COSMOLOGICAL MINIHALOS (2007)
Paul R. Shapiro, Alejandro C. Raga
Las primeras fuentes de radiacion ionizante que se condensaron del medio intergalactico fro y neutro produjeron frentes de ionizacion que se propagaron en sus alrededores y alcanzaron a otras...
THE EFFECT OF GASDYNAMICS ON THE STRUCTURE OF DARK (2007)
Matter Halos, Marcelo Alvarez, Paul R. Shapiro, Hugo Martel
Presentamos simulaciones de N-cuerpos hechas con HPS adaptivo (Hidrodinamica de Partculas Suaves), para estudiar el efecto de la dinamica de gas sobre la estructura de halos de materia oscura que...
THE EQUILIBRIUM STRUCTURE OF COSMOLOGICAL HALOS: FROM DWARF GALAXIES TO X{RAY CLUSTERS (2007)
Ilian T. Iliev, Paul R. Shapiro
Se describe un nuevo modelo para la estructura de equilibrio post{colapso de objetos virializados que se condensan del fondo cosmologico del universo y se compara con observaciones y simulaciones de...
RevMexAA (Serie de Conferencias), 10, 101-108 (2001) (2007)
Explosions During Galaxy, Hugo Martel, Paul R. Shapiro
As an idealized model of the eects of energy release by supernovae during galaxy formation, we consider an explosion at the center of a halo which forms at the intersection of laments in the plane of...
RevMexAA (Serie de Conferencias), 10, 109--114 (2001) (2007)
Reionization Of The, Paul R. Shapiro, Alejandro C. Raga
The first sources of ionizing radiation to condense out of the dark and neutral IGM sent ionization fronts sweeping outward through their surroundings, overtaking other condensed objects and...
RevMexAA (Serie de Conferencias), 10, 124--129 (2001) (2007)
The Effect Of, Matter Halos, Marcelo Alvarez, Paul R. Shapiro, Hugo Martel
Adaptive SPH and N-body simulations were carried out to study the e#ect of gasdynamics on the structure of dark matter halos that result from the gravitational instability and fragmentation of...
RevMexAA (Serie de Conferencias), 10, 138--143 (2001) (2007)
The Equilibrium Structure, Ilian T. Iliev, Paul R. Shapiro
A new model for the postcollapse equilibrium structure of virialized objects which condense out of the cosmological background universe is described and compared with observations and simulations of...
RevMexAA (Serie de Conferencias), 9, 292--299 (2000) (2007)
Reionization Of The, Paul R. Shapiro, Alejandro C. Raga, Autónoma México
The first sources of ionizing radiation to condense out of the dark and neutral IGM sent ionization fronts sweeping outward through their surroundings, overtaking other condensed objects and...
Iliev, Ilian T., Shapiro, Paul R., McDonald, Patrick, Mellema, Garrelt, Pen, Ue-Li
Observations of high-redshift Ly-alpha sources are a major tool for studying the high-redshift Universe. We discuss the effect of the reionizing intergalactic medium on the observability of Ly-alpha...
On The Survival and Abundance of Disk-dominated Galaxies (2007)
Koda, Jun, Milosavljevic, Milos, Shapiro, Paul R.
We study the formation of disk-dominated galaxies in a Lambda CDM universe. Their existence is considered to be a challenge for the Lambda CDM cosmology, because galaxy mergers isotropize stellar...
Reionization: Characteristic Scales, Topology and Observability (2007)
Iliev, Ilian T., Shapiro, Paul R., Mellema, Garrelt, Pen, Ue-Li, McDonald, Patrick, Alvarez, Marcelo A.
Recently the numerical simulations of the process of reionization of the universe at z>6 have made a qualitative leap forward, reaching sufficient sizes and dynamic range to determine the...
Simulating Reionization: Character and Observability (2007)
Iliev, Ilian T., Shapiro, Paul R., Mellema, Garrelt, Pen, Ue-Li, McDonald, Patrick, Bond, J. Richard
In recent years there has been considerable progress in our understanding of the nature and properties of the reionization process. In particular, the numerical simulations of this epoch have made a...
Feedback from first radiation sources: H- photodissociation (2007)
Chuzhoy, Leonid, Kuhlen, Michael, Shapiro, Paul R.
During the epoch of reionization, the formation of radiation sources is accompanied by the growth of a H- photodissociating flux. We estimate the impact of this flux on the formation of molecular...
The Cluster-Merger Shock in 1E 0657-56: Faster than the Speeding Bullet? (2007)
Milosavljevic, Milos, Koda, Jun, Nagai, Daisuke, Nakar, Ehud, Shapiro, Paul R.
Shock waves driven in the intergalactic medium during the merging of galaxy clusters have been observed in X-ray imaging and spectroscopy. Fluid motions inferred from the shock strength and...
Current models of the observable consequences of cosmic reionization and their detectability (2007)
Iliev, Ilian T., Mellema, Garrelt, Pen, Ue-Li, Bond, J. Richard, Shapiro, Paul R.
A number of large current experiments aim to detect the signatures of the Cosmic Reionization at redshifts z>6. Their success depends crucially on understanding the character of the reionization...
The Signature of Patchy Reionization in the Polarization Anisotropy of the CMB (2007)
Doré, Olivier, Holder, Gil, Alvarez, Marcelo, Iliev, Ilian T., Mellema, Garrelt, Pen, Ue-Li, ...
The inhomogeneous ionization state of the universe when the first sources of ionizing radiation appeared should lead to anisotropies in the polarization of the cosmic microwave background. We use...
Iliev, Ilian T., Pen, Ue-Li, Bond, J. Richard, Mellema, Garrelt, Shapiro, Paul R.
We present the first calculation of the kinetic Sunyaev-Zel'dovich (kSZ) effect due to the inhomogeneous reionization of the universe based on detailed large-scale radiative transfer simulations of...
Ahn, Kyungjin, Shapiro, Paul R.
We study the effect of starlight from the first stars on the ability of other minihaloes in their neighborhood to form additional stars. The question of what the dynamical consequences were for these...
Self-regulated reionization (2006)
Iliev, Ilian T., Mellema, Garrelt, Shapiro, Paul R., Pen, Ue-Li
Recently, we have presented the first large-scale radiative transfer simulations of reionization. Here we present new simulations which extend the source halo mass range downward to 10^8M_solar, to...
Explosions During Galaxy Formation (2006)
Explosions During Galaxy Formation
Reionization of the Universe and the Photoevaporation of Cosmological Minihalos (2006)
Reionization of the Universe and the Photoevaporation of Cosmological Minihalos
The Effect of Gasdynamics on the Structure of Dark Matter Halos (2006)
Paul R. Shapiro, Hugo Martel, Marcelo Alvarez
The Effect of Gasdynamics on the Structure of Dark Matter Halos
The Equilibrium Structure of Cosmological Halos: From Dwarf Galaxies to X-ray Clusters (2006)
Paul R. Shapiro, Ilian T. Iliev
The Equilibrium Structure of Cosmological Halos: From Dwarf Galaxies to X-ray Clusters
Reionization of the universe and the photoevaporation of cosmological minihalos (2006)
Paul R. Shapiro, Alejandro C. Raga
Reionization of the universe and the photoevaporation of cosmological minihalos
The Kinetic Sunyaev-Zel'dovich Effect from Patchy Reionization: the View from the Simulations (2006)
Iliev, Ilian T., Pen, Ue-Li, Bond, J. Richard, Mellema, Garrelt, Shapiro, Paul R.
We present the first calculation of the kinetic Sunyaev-Zel'dovich (kSZ) effect due to the inhomogeneus reionization of the universe based on detailed large-scale radiative transfer simulations of...
Recognizing the First Radiation Sources Through Their 21-cm Signature (2006)
Chuzhoy, Leonid, Alvarez, Marcelo A., Shapiro, Paul R.
At the beginning of the reionization epoch, radiation sources produce fluctuations in the redshifted 21-cm background. We show that different types of sources (such as miniquasars, Pop II and III...
Heating and cooling of the intergalactic medium by resonance photons (2006)
Chuzhoy, Leonid, Shapiro, Paul R.
During the epoch of reionization a large number of photons were produced with frequencies below the hydrogen Lyman limit. After redshifting into the closest resonance, these photons underwent...
Implications of WMAP 3 Year Data for the Sources of Reionization (2006)
Alvarez, Marcelo A., Shapiro, Paul R., Ahn, Kyungjin, Iliev, Ilian T.
New results on the anisotropy of the cosmic microwave background (CMB) and its polarization based on the first 3 years of data from the Wilkinson Microwave Anisotropy Probe (WMAP) have revised the...
Mellema, Garrelt, Iliev, Ilian T., Pen, Ue-Li, Shapiro, Paul R.
We present detailed predictions for the redshifted 21cm signal from the epoch of reionization. These predictions are obtained from radiative transfer calculations on the results of large scale (100/h...
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...
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., ...
Dynamical HII Region Evolution in Turbulent Molecular Clouds (2005)
Mellema, Garrelt, Arthur, S. Jane, Henney, William J., Iliev, Ilian T., Shapiro, Paul R.
We present numerical radiation-hydrodynamic simulations of the evolution of HII regions formed in an inhomogeneous medium resulting from turbulence simulations. We find that the filamentary structure...
Shapiro, Paul R., Ahn, Kyungjin, Alvarez, Marcelo A., Iliev, Ilian T., Martel, Hugo, Ryu, Dongsu
The H atoms inside minihalos (i.e. halos with virial temperatures T_vir < 10^4 K, in the mass range roughly from 10^4 M_sun to 10^8 M_sun) during the cosmic dark ages in a LambdaCDM universe produce...
Simulating Cosmic Reionization at Large Scales I: the Geometry of Reionization (2005)
Iliev, Ilian T., Mellema, Garrelt, Pen, Ue-Li, Merz, Hugh, Shapiro, Paul R., Alvarez, Marcelo A.
We present the first large-scale radiative transfer simulations of cosmic reionization, in a simulation volume of (100/h Mpc)^3, while at the same time capturing the dwarf galaxies which are...
Chuzhoy, Leonid, Shapiro, Paul R.
We present new analytic calculations of the coupling between ultraviolet resonance photons and the population of the hyperfine states in the light elements (H, D, He3+) which include several...
The Cosmic Reionization History as Revealed by the CMB Doppler--21-cm Correlation (2005)
Alvarez, Marcelo A., Komatsu, Eiichiro, Doré, Olivier, Shapiro, Paul R.
We show that the epoch(s) of reionization when the ionization fraction of the universe is about half can be determined by correlating Cosmic Microwave Background (CMB) temperature maps with 21-cm...
Understanding the Equilibrium Structure of CDM Halos (2005)
Shapiro, Paul R., Ahn, Kyungjin, Alvarez, Marcelo, Iliev, Ilian T., Martel, Hugo
N-body simulations find a universal structure for the halos which result from the nonlinear growth of Gaussian-random-noise density fluctuations in the CDM universe. This talk summarized our attempts...
Ahn, Kyungjin, Shapiro, Paul R., Alvarez, Marcelo A., Iliev, Ilian T., Martel, Hugo, Ryu, Dongsu
The H atoms inside minihalos (i.e. halos with virial temperatures T_vir < 10^4 K, in the mass range roughly from 10^4 M_sun to 10^8 M_sun) during the cosmic dark ages in a LCDM universe produce a...
C^2-Ray: A new method for photon-conserving transport of ionizing radiation (2005)
Mellema, Garrelt, Iliev, Ilian T., Alvarez, Marcelo A., Shapiro, Paul R.
We present a new numerical method for calculating the transfer of ionizing radiation, called C^2-Ray=Conservative, Causal Ray-tracing method. The method is explicitly photon-conserving, so the...
Relativistic Ionization Fronts (2005)
Shapiro, Paul R., Iliev, Ilian T., Alvarez, Marcelo A., Scannapieco, Evan
We derive the equations for the propagation of relativistic ionization fronts in both static and moving gases. We focus on the supersonic R-type phase that occurs right after a source turns on, and...
The H II Region of the First Star (2005)
Alvarez, Marcelo A., Bromm, Volker, Shapiro, Paul R.
Simulations predict that the first stars in an LCDM universe formed at redshifts z>20 in minihalos with masses of about 10^6 M_sun. We have studied their radiative feedback by simulating the...
Iliev, Ilian T., Shapiro, Paul R., Scannapieco, Evan, Mellema, Garrelt, Alvarez, Marcelo A., Raga, Alejandro C., ...
The propagation of cosmological ionization fronts (I-fronts) during reionization is strongly influenced by small-scale structure. Here we summarize our recent attemps to understand the effect of this...
Fragmentation and Evolution of Molecular Clouds. I: Algorithm and First Results (2005)
Martel, Hugo, Evans II, Neal J., Shapiro, Paul R.
We present a series of simulations of the fragmentation of a molecular cloud, leading to the formation of a cluster of protostellar cores. The purpose of these simulations is to address a specific...
Formation and Evolution of the Self-Interacting Dark Matter Halos (2004)
Ahn, Kyungjin, Shapiro, Paul R.
We have derived the first, fully-cosmological, similarity solutions for CDM halo formation in the presence of nongravitational collisionality, which provides an analytical theory of the effect of the...
The Impact of Small-Scale Structure on Cosmological Ionization Fronts and Reionization (2004)
Iliev, Ilian T., Scannapieco, Evan, Shapiro, Paul R.
The propagation of cosmological ionization fronts during the reionization of the universe is strongly influenced by small-scale gas inhomogeneities due to structure formation. These inhomogeneities...
The Equilibrium Structure of CDM Halos (2004)
Shapiro, Paul R., Iliev, Ilian T., Martel, Hugo, Ahn, Kyungjin, Alvarez, Marcelo A.
Dark-matter halos are the scaffolding around which galaxies and clusters are built. They form when the gravitational instability of primordial density fluctuations causes regions which are denser...
Iliev, Ilian T., Shapiro, Paul R., Raga, Alejandro C.
The weak, R-type ionization fronts (I-fronts) which swept across the intergalactic medium (IGM) during the reionization of the universe often found their paths blocked by cosmological minihaloes....
Photoevaporation of Cosmological Minihalos during Reionization (2003)
Shapiro, Paul R., Iliev, Ilian T., Raga, Alejandro C.
We present the first gas dynamical simulations of the photoevaporation of cosmological minihalos overtaken by the ionization fronts which swept through the IGM during reionization in a LCDM universe,...
Gravitational Lensing by CDM Halos: Singular versus Nonsingular Profiles (2003)
Martel, Hugo, Shapiro, Paul R.
The gravitational lensing properties of cosmological halos depend upon the mass distribution within each halo. The description of halos as nonsingular, truncated isothermal spheres, a particular...
The Formation and Evolution of Self-Interacting Dark Matter Halos (2003)
Ahn, Kyungjin, Shapiro, Paul R.
We study the formation and evolution of self-interacting dark matter (SIDM) halos. We find analytical, fully cosmological similarity solutions for their dynamics, which take proper account of the...
On the Detectability of the Cosmic Dark Ages: 21-cm Lines from Minihalos (2003)
Martel, Hugo, Shapiro, Paul R., Iliev, Ilian T., Scannapieco, Evan, Ferrara, Andrea
In the standard Cold Dark Matter (CDM) theory of structure formation, virialized minihalos (with T_vir = 10,000 K or less) form in abundance at high redshift (z > 6), during the cosmic "dark ages."...
Density Profiles of Dark Halos from their Mass Accretion Histories (2003)
Alvarez, Marcelo A., Ahn, Kyungjin, Shapiro, Paul R.
We use the universal mass accretion history recently reported for simulations of halo formation in the cold dark matter model (CDM) to analyze the formation and growth of a single halo. We derive the...
Photoevaporation of Minihalos during Reionization (2003)
Shapiro, Paul R., Iliev, Ilian T., Raga, Alejandro C., Martel, Hugo
We present the first gas dynamical simulations of the photoevaporation of cosmological minihalos overtaken by the ionization fronts which swept through the IGM during reionization in a LCDM universe,...
Formation and Evolution of Self-Interacting Dark Matter Halos (2002)
Ahn, Kyungjin, Shapiro, Paul R.
We study the formation and evolution of self-interacting dark matter (SIDM) halos. We find analytical, fully cosmological similarity solutions taking account of the collisional interaction of SIDM...
Iliev, Ilian T., Scannapieco, Evan, Martel, Hugo, Shapiro, Paul R.
Hydrogen atoms inside virialized minihalos generate a radiation background from redshifted 21-cm line emission whose angular fluctuations reflect clustering during before and during reionization. We...
A Model for the Formation and Evolution of Cosmological Halos (2002)
Alvarez, Marcelo A., Shapiro, Paul R., Martel, Hugo
Adaptive SPH and N-body simulations were carried out to study the collapse and evolution of dark matter halos that result from the gravitational instability and fragmentation of cosmological...
Martel, Hugo, Shapiro, Paul R.
The gravitational lensing properties of cosmological halos depend upon the mass distribution within each halo. The description of halos as nonsingular, truncated isothermal spheres, a particular...
On the Direct Detectability of the Cosmic Dark Ages: 21-cm Emission from Minihalos (2002)
Iliev, Ilian T., Shapiro, Paul R., Ferrara, Andrea, Martel, Hugo
In the standard Cold Dark Matter (CDM) theory of structure formation, virialized minihalos (with T_vir}6), during the cosmic ``dark ages.'' The hydrogen in these minihalos, the first nonlinear...
A simple method is presented for diagnosing the electron temperature and density of a rapidly heated, coronal-type plasma from observable, non-equilibrium enhancements of X-ray line emission. This...
Formation and Evolution of Self-Interacting Dark Matter Halos (2002)
Ahn , Kyungjin, Shapiro , Paul R.
We study the formation and evolution of self-interacting dark matter (SIDM) halos. We find analytical, fully cosmological similarity solutions for their dynamics, which take proper account of the...
The Universal Equilibrium of CDM Halos: Making Tracks on the Cosmic Virial Plane (2001)
Iliev, Ilian T., Shapiro, Paul R.
Dark-matter halos are the scaffolding around which galaxies and clusters are built. They form when the gravitational instability of primordial density fluctuations causes regions which are denser...
Cosmological Simulations with Adaptive Smoothed Particles Hydrodynamics (2001)
Martel, Hugo, Shapiro, Paul R.
We summarize the ideas that led to the Adaptive Smoothed Particle Hydrodynamics (ASPH) algorithm, with anisotropic smoothing and shock-tracking. We then identify a serious new problem for SPH...
The Central Mass and Phase-Space Densities of Dark Matter Halos: Cosmological Implications (2001)
Shapiro, Paul R., Iliev, Ilian T.
Current data suggest that the central mass densities $\rho_0$ and phase-space densities $Q\equiv\rho_0/\sigma_V^3$ of cosmological halos in the present universe are correlated with their velocity...
Cosmological Reionization (2001)
The universe was reionized by redshift z ~ 6 by a small fraction of the baryons in the universe, which released energy following their condensation out of a cold, dark, and neutral IGM into the...
Explosions and Outflows during Galaxy Formation (2001)
Martel, Hugo, Shapiro, Paul R.
We consider an explosion at the center of a halo which forms at the intersection of filaments inside a cosmological pancake, a convenient test-bed model for galaxy formation. ASPH/P3M simulations...
The Equilibrium Structure of Cosmological Halos (2001)
Iliev, Ilian T., Shapiro, Paul R.
We have derived an analytical model for the postcollapse equilibrium structure of cosmological halos as nonsingular truncated isothermal spheres (TIS) and compared this model with observations and...
The Evolution of Dark-Matter Dominated Cosmological Halos (2001)
Alvarez, Marcelo, Shapiro, Paul R., Martel, Hugo
Adaptive SPH and N-body simulations were carried out to study the evolution of the equilibrium structure of dark matter halos that result from the gravitational instability and fragmentation of...
The Postcollapse Equilibrium Structure of Cosmological Haloes in a Low-Density Universe (2001)
Iliev, Ilian T., Shapiro, Paul R.
An analytical model is presented for the postcollapse equilibrium structure of virialized objects which condense out of a low-density cosmological background universe, either matter-dominated or flat...
Explosions during galaxy formation (2001)
Martel , Hugo, Shapiro , Paul R.
As an idealized model of the e ects of energy release by supernovae during galaxy formation, we consider an explosion at the center of a halo which forms at the intersection of laments in the plane...
Reionization of the universe and the photoevaporation of cosmological minihalos (2001)
The rst sources of ionizing radiation to condense out of the dark and neutral IGM sent ionization fronts sweeping outward through their surroundings, overtaking other condensed objects and...
The effect of gasdynamics on the structure of dark matter halos (2001)
Alvarez , Marcelo, Martel , Hugo, Shapiro , Paul R.
Adaptive SPH and N-body simulations were carried out to study the e ect of gasdynamics on the structure of dark matter halos that result from the gravitational instability and fragmentation of...
The equilibrium structure of cosmological halos: from dwarf galaxies to x-ray clusters (2001)
Iliev , Ilian T., Shapiro , Paul R.
A new model for the postcollapse equilibrium structure of virialized objects which condense out of the cosmological background universe is described and com- pared with observations and simulations...
On the Origin of the Rotation Curves of Dark-Matter-Dominated Galaxies (2000)
Iliev, Ilian T., Shapiro, Paul R.
Rotation curves of dark-matter-dominated galaxies measure the mass profiles of galactic halos and thereby test theories of their cosmological origin. While attention has focused lately on the...
The Reionization of the Universe and the Photoevaporation of Cosmological Minihalos (2000)
Shapiro, Paul R., Raga, Alejandro C.
The first sources of ionizing radiation to condense out of the dark and neutral IGM sent ionization fronts sweeping outward through their surroundings, overtaking other condensed objects and...
On the Mass Profile of Galaxy Cluster CL 0024+1654 Inferred from Strong Lensing (2000)
Shapiro, Paul R., Iliev, Ilian T.
Observations of a flat density profile in the cores of dark-matter-dominated halos on the two extremes of mass for virialized objects in the universe, dwarf galaxies and galaxy clusters, present a...
Explosions During Galaxy Formation (2000)
Martel, Hugo, Shapiro, Paul R.
As an idealized model of the effects of energy release by supernovae during galaxy formation, we consider an explosion at the center of a halo which forms at the intersection of filaments in the...
The Effect of Gasdynamics on the Structure of Dark Matter Halos (2000)
Alvarez, Marcelo, Shapiro, Paul R., Martel, Hugo
Adaptive SPH and N-body simulations were carried out to study the effect of gasdynamics on the structure of dark matter halos that result from the gravitational instability and fragmentation of...
The Equilibrium Structure of Cosmological Halos: Dwarf Galaxies to X-ray Clusters (2000)
Iliev, Ilian T., Shapiro, Paul R.
An analytical model for the postcollapse equilibrium structure of virialized objects which condense out of the cosmological background universe is described and compared with observations and...
Reionization of the Universe by Starlight and the Photoevaporation of Cosmological Minihalos (2000)
Shapiro, Paul R., Raga, Alejandro C.
The first sources of ionizing radiation to condense out of the dark and neutral IGM sent ionization fronts sweeping outward through their surroundings, overtaking other condensed objects and...
The Equilibrium Structure of Cosmological Halos: From Dwarf Galaxies to X-ray Clusters (2000)
Shapiro, Paul R., Iliev, Ilian T.
A new model for the postcollapse equilibrium structure of virialized objects which condense out of the cosmological background universe is described and compared with observations and simulations of...
Reionization of the Universe and the Photoevaporation of Cosmological Minihalos (2000)
Shapiro, Paul R., Raga, Alejandro C.
The first sources of ionizing radiation to condense out of the dark and neutral IGM sent ionization fronts sweeping outward through their surroundings, overtaking other condensed objects and...
Reionization of the universe and the photoevaporation of cosmological minihalos (2000)
Raga , Alejandro C., Shapiro , Paul R.
The rst sources of ionizing radiation to condense out of the dark and neutral IGM sent ionization fronts sweeping outward through their surroundings, overtaking other condensed objects and...
Explosions During Galaxy Formation. Scale-Free Simulations (1999)
Martel, Hugo, Shapiro, Paul R.
When density fluctuations collapse gravitationally out of the expanding cosmological background universe to form galaxies, the secondary energy release which results can affect their subsequent...
The Asymptotic Collapsed Fraction in an Eternal Universe (1999)
Martel, Hugo, Shapiro, Paul R.
We calculate the maximum fraction of matter which is able to condense out of the expanding background universe, for any universe which will expand forever. We use a simple spherical model for the...
Shapiro, Paul R., Iliev, Ilian T., Raga, Alejandro C.
The postcollapse structure of objects which form by gravitational condensation out of the expanding cosmological background universe is a key element in the theory of galaxy formation. Towards this...
Radiative Feedback and the Photoevaporation of Intergalactic Clouds (1998)
Shapiro, Paul R., Raga, Alejandro C., Mellema, Garrelt
The first sources of ionizing radiation to condense out of the dark and neutral IGM sent ionization fronts sweeping outward through their surroundings, overtaking other primordial gas-clouds and...
Reionization Feedback and the Photoevaporation of Intergalactic Clouds (1997)
Shapiro, Paul R., Raga, Alejandro C., Mellema, Garrelt
Energy released by a small fraction of the baryons in the universe, which condensed out of while the IGM was cold, dark, and neutral,reheated and reionized it, exposing gas clouds within it to the...
A Convenient Set of Comoving Cosmological Variables and Their Application (1997)
Martel, Hugo, Shapiro, Paul R.
We present a set of cosmological variables, called "supercomoving variables," which are particularly useful for describing the gas dynamics of cosmic structure formation. For ideal gas with...
Likely Values of the Cosmological Constant (1997)
Martel, Hugo, Shapiro, Paul R., Weinberg, Steven
In theories in which the cosmological constant Lambda takes a variety of values in different ``subuniverses,'' the probability distribution of its observed values is conditioned by the requirement...
Gravitational Instability in Collisionless Cosmological Pancakes (1996)
Valinia, Azita, Shapiro, Paul R., Martel, Hugo, Vishniac, Ethan T.
The gravitational instability of cosmological pancakes composed of collisionless dark matter in an Einstein-de Sitter universe is investigated numerically to demonstrate that pancakes are unstable...
Adaptive Smoothed Particle Hydrodynamics: Methodology II (1995)
Owen, J. Michael, Villumsen, Jens V., Shapiro, Paul R., Martel, Hugo
This paper presents an alternative formulation of the ASPH algorithm for evolving anisotropic smoothing kernels, in which the geometric approach of Shapiro et al. (1996; Paper I) is replaced by an...