Measuring the History of Cosmic Reionization using the 21-cm PDF from Simulations (2009)
Ichikawa, Kazuhide, Barkana, Rennan, Iliev, Ilian T., Mellema, Garrelt, Shapiro, Paul
The 21-cm PDF (i.e., distribution of pixel brightness temperatures) is expected to be highly non-Gaussian during reionization and to provide important information on the distribution of density and...
A Physical Model of Lyman Alpha Emitters (2009)
Tilvi, Vithal, Malhotra, Sangeeta, Rhoads, James E., Scannapieco, Evan, Thacker, Robert J., Iliev, Ilian T., ...
We present a simple physical model for populating dark matter halos with Lyman Alpha Emiiters(LAEs) and predict the physical properties of LAEs at z~3-7. The central tenet of this model is that the...
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....
Harker, Geraint J. A., Zaroubi, Saleem, Thomas, Rajat M., Jelic, Vibor, Labropoulos, Panagiotis, Mellema, Garrelt, ...
Scale-dependent bias induced by local non-Gaussianity: A comparison to N-body simulations (2008)
Desjacques, Vincent, Seljak, Uros, Iliev, Ilian T.
We investigate the effect of primordial non-Gaussianity of the local f_NL type on the auto- and cross-power spectrum of dark matter haloes using simulations of the LCDM cosmology. We perform a series...
Harker, Geraint J. A., Zaroubi, Saleem, Thomas, Rajat M., Jelic, Vibor, Labropoulos, Panagiotis, Mellema, Garrelt, ...
Detecting redshifted 21cm emission from neutral hydrogen in the early Universe promises to give direct constraints on the epoch of reionization (EoR). It will, though, be very challenging to extract...
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...
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...
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, 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...
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...
Fate of clumps in damped Lyalpha systems (2007)
Iliev, Ilian T., Hirashita, Hiroyuki, Ferrara, Andrea
Recent observations have revealed that damped Ly$\alpha$ clouds (DLAs) host star formation activity. In order to examine if such star formation activity can be triggered by ionization fronts, we...
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...
Weinmann, Simone M., Maccio', Andrea V., Iliev, Ilian T., Mellema, Garrelt, Moore, Ben
The reionization of the Universe has profound effects on the way galaxies form and on their observed properties at later times. Of particular importance is the relative timing of the reionization...
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...
Holder, Gilbert, Iliev, Ilian T., Mellema, Garrelt
Large fluctuations in the electron column density can occur during the reionization process. We investigate the possibility of deriving the electron density fluctuations through detailed mapping of...
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...
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...
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
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...
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...
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...
Fate of clumps in damped Ly$\alpha$ systems (2005)
Iliev, Ilian T., Hirashita, Hiroyuki, Ferrara, Andrea
Recent observations have revealed that damped Ly$\alpha$ clouds (DLAs) host star formation activity. In order to examine if such star formation activity can be triggered by ionization fronts, we...
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...
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...
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,...
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."...
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,...
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...
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...
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...
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...
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 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...
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...
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...
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...
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...
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...