Adi Nusser

Ergodic Considerations in the Gravitational Potential of the Milky Way (2009)

Nusser, Adi

A method is proposed for constraining the Galactic gravitational potential from high precision observations of the phase space coordinates of a system of relaxed tracers. The method relies on an...

Decontamination of cosmological 21-cm maps (2008)

Gleser, Liron, Nusser, Adi, Benson, Andrew J.

We present a method for extracting the expected cosmological 21-cm signal from the epoch of re-ionization, taking into account contaminating radiations and random instrumental noise. The method is...

Gravo-thermodynamics of the Intracluster Medium: negative heat capacity and dilation of cooling time scales (2008)

Nusser, Adi

The time scale for cooling of the gravitationally bound gaseous intracluster medium (ICM) is not determined by radiative processes alone. If the ICM is in quasi-hydrostatic equilibrium in the fixed...

Searching for Neutrinos from WIMP Annihilations in the Galactic Stellar Disk (2008)

Myers, Zacharia, Nusser, Adi

Weakly interacting massive particles (WIMPs) are a viable candidate for the relic abundance of dark matter (DM) produced in the early universe. So far WIMPs have eluded direct detection through...

De-contamination of cosmological 21-cm maps (2007)

Gleser, Liron, Nusser, Adi, Benson, Andrew J.

We present a method for extracting the expected cosmological 21-cm signal from the epoch of reionization, taking into account contaminating radiations and random instrumental noise. The method is...

COMPARISON OF VELOCITY AND GRAVITY FIELDS: THE MARK III TULLY-FISHER CATALOG VERSUS THE IRAS 1.2 JY SURVEY Marc Davis (2007)

Marc Davis, Adi Nusser, Jeffrey A. Willick

We consider a measure of the peculiar velocity field derived from the Mark III compilation of 2900 spiral galaxies (Willick et al. 1996b), using an analysis method that is substantially free of bias...

The Amplitude of Mass Density Fluctuations At (2007)

From The Forest, Adi Nusser, Martin Haehnelt

The real-space optical depth distribution along the line of sight to the QSO Q1422+231 is recovered from two HIRES spectra using a modified version of the inversion method proposed by Nusser &...

A first step towards a direct inversion of the Lyman forest in QSO spectra (2007)

Adi Nusser, Martin Haehnelt

A method for the recovery of the real space line-of-sight mass density field from Lyman absorption in QSO spectra is presented. The method makes use of a Lucytype algorithm for the recovery of the HI...

Indications Of Dark Matter Derived From Large Scale Flows (2007)

Marc Davis And, Marc Davis, Adi Nusser

Recent progress in the measurement of relative distances to galaxies has been quite substantial, and catalogs of 3000 galaxies with distances are soon to become available. The peculiar velocity field...

A first step towards a direct inversion of the Lyman forest in QSO spectra (2007)

Adi Nusser, Martin Haehnelt

A method for the recovery of the real space line-of-sight mass density field from Lyman absorption in QSO spectra is presented. The method makes use of a Lucytype algorithm for the recovery of the HI...

Mass Growth and Density Profiles of Dark Matter Halos in Hierarchical Clustering (2007)

Adi Nusser, Ravi K. Sheth

We develop a model for the growth of dark matter halos and use it to study their evolved density profiles. In this model, halos are spherical and form by quiescent accretion of matter in clumps,...

Hydrostatic equilibrium of a porous intracluster medium: implications for mass fraction and X-ray luminosity (2007)

Nusser, Adi, Silk, Joe

The presence of dilute hot cavities in the intracluster medium (ICM) at the cores of clusters of galaxies changes the relation between gas temperature and its X-ray emission properties. Using the...

Boundary-value problems in cosmological dynamics (2007)

Nusser, Adi

The dynamics of cosmological gravitating system is governed by the Euler and the Poisson equations. Tiny fluctuations near the big bang singularity are amplified by gravitational instability into the...

Neutralino Annihilations and the Gas Temperature in the Dark Ages (2007)

Myers, Zac, Nusser, Adi

Assuming the dark matter is made entirely from neutralinos, we re-visit the role of their annihilation on the temperature of diffuse gas in the high redshift universe. We consider neutralinos of...

Back-in-time dynamics of the cluster IE 0657-56 (the Bullet System) (2007)

Nusser, Adi

We present a simplified dynamical model of the ``Bullet'' system of two colliding clusters. The model constrains the masses of the system by requiring that the orbits of the main and sub components...

Halo Assembly Bias in the Quasi-linear Regime (2007)

Keselman, Jose Ariel, Nusser, Adi

We address the question of whether or not assembly bias arises in the absence of highly non-linear effects such as tidal stripping of halos near larger mass concentrations. Therefore, we use a...

General Relativistic Self-Similar Solutions in Cosmology (2006)

Nusser, Adi

We present general relativistic solutions for self-similar spherical perturbations in an expanding cosmological background of cold pressure-less gas. We focus on solutions having shock...

The Probability Distribution of the Lya transmitted flux from a sample of SDSS quasars (2006)

Desjacques, Vincent, Nusser, Adi, Sheth, Ravi K.

We present a measurement of the probability distribution function (PDF) of the transmitted flux in the Lya forest from a sample of 3492 quasars included in the SDSS DR3 data release. Our intention is...

The morphology of cosmological reionization by means of Minkowski Functionals (2006)

Gleser, Liron, Nusser, Adi, Ciardi, Benedetta, Desjacques, Vincent

The morphology of the total gas and the neutral hydrogen (H I) distributions during the cosmological epoch of reionization can be quantified with Minkowski Functionals (MFs) of isodensity surfaces....

Suppressing cluster cooling flows by self-regulated heating from spatially distributed population of AGNs (2006)

Nusser, Adi, Silk, Joseph, Babul, Arif

(Abridged) Existing models invoking AGN activty to resolve the cooling flow conundrum in galaxy clusters focus exclusively on the role of the central galaxy. Such models require fine-tuning of highly...

Numerical action reconstruction of the dynamical history of dark matter haloes in N-body simulations (2005)

Phelps, Steven, Desjacques, Vincent, Nusser, Adi, Shaya, Edward J.

We test the ability of the numerical action method (NAM) to recover the individual orbit histories of mass tracers in an expanding universe in a region of radius 26Mpc/h, given the masses and...

The Epoch of Reionization (2005)

Benson, A. J., Sugiyama, Naoshi, Nusser, Adi, Lacey, C. G.

We have modelled the process of reionization of the IGM by photoionization by galaxies, in order to predict the epoch of reionization. We use a sophisticated semi-analytic model to track the...

The impact of galactic winds from LBGs on the Intergalactic Medium (2005)

Desjacques, Vincent, Haehnelt, Martin G., Nusser, Adi

An excess of sight-lines close to Lyman-break galaxies (LBGs) with little or no absorption in QSO absorption spectra has been reported and has been interpreted as the effect of galactic winds on the...

Modeling the formation of galaxy clusters in MOND (2005)

Nusser, Adi, Pointecouteau, Etienne

We use a one dimensional hydrodynamical code to study the evolution of spherically symmetric perturbations in the framework of Modified Newtonian Dynamics (MOND). The code evolves spherical gaseous...

Instabilities of Galactic Disks in the Presence of Star Formation (2005)

Nusser, Adi

We discuss the stability of galactic disks in which the energy of interstellar clouds is gained in encounters with expanding supernova remnants and lost in inelastic collisions. Energy gain and loss...

Patchy He II reionization and the physical state of the IGM (2004)

Gleser, Liron, Nusser, Adi, Benson, Andrew J., Ohno, Hiroshi, Sugiyama, Naoshi

We present a Monte-Carlo model of He II reionization by QSOs and its effect on the thermal state of the clumpy intergalactic medium (IGM). The model assumes that patchy reionization develops as a...

Joint modeling of the probability distribution and power spectrum of the Lya forest: comparison with observations at z=3 (2004)

Desjacques, Vincent, Nusser, Adi

We presents results of joint modeling of the probability distribution function (PDF) and the one-dimensional power spectrum (PS) of the Lya forest flux decrement. The sensitivity of these statistical...

The Alcock-Paczynski test in redshifted twenty one centimeter maps (2004)

Nusser, Adi

We examine the possibility of constraining the cosmological mean mass and dark energy densities by an application of the Alcock-Paczynski test on redshifted 21-cm maps of the epoch of reionization....

The spin temperature of neutral hydrogen during cosmic pre-reionization (2004)

Nusser, Adi

We re-examine the role of collisions in decoupling the HI 21-cm spin temperature from the cosmic microwave background (CMB). The cross section for de-exciting the 21-cm trasition in collisions with...

Consequences of short range interactions between dark matter and protons in galaxy clusters (2004)

Chuzhoy, Leonid, Nusser, Adi

Protons gain energy in short range collisions with heavier dark matter particles (DMPs) of comparable velocity dispersion. We examine the conditions under which the heating of baryons by scattering...

Monitoring lensed starlight emitted close to the Galactic Center (2004)

Nusser, Adi, Broadhurst, Tom

We describe the feasibility of detecting the gravitational deflection of light emitted by stars moving under the influence of the massive object at the Galactic center. Light emitted by a star...

Redshift distortions in one-dimensional power spectra (2004)

Desjacques, Vincent, Nusser, Adi

We present a model for one-dimensional (1D) matter power spectra in redshift space as estimated from data provided along individual lines of sight. We derive analytic expressions for these power...

Galactic winds and the Lya forest (2003)

Desjacques, Vincent, Nusser, Adi, Haehnelt, Martin G., Stoehr, Felix

We study the effect of galactic outflows on the Lya forest. The winds are modelled as fully ionised spherical bubbles centered around galactic haloes. The observed flux probability distribution and...

Superclusters with thermal Sunyaev-Zel'dovich effect surveys (2003)

Diaferio, Antonaldo, Nusser, Adi, Yoshida, Naoki, Sunyaev, Rashid A.

We use a simple analytic model to compute the angular correlation function of clusters identified in upcoming thermal Sunyaev-Zel'dovich (SZ) effect surveys. We then compute the expected fraction of...

Statistics of Neutral Regions During Hydrogen Re-Ionization (2002)

Nusser, Adi, Benson, Andrew, Sugiyama, Naoshi, Lacey, Cedric

We present predictions for two statistical measures of the hydrogen reionization process at high redshift. The first statistic is the number of neutral segments identified in spectra of high redshift...

Superclusters with thermal SZ effect surveys (2002)

Diaferio, Antonaldo, Nusser, Adi, Yoshida, Naoki, Sunyaev, Rashid A.

We use a simple analytic model to compute the angular correlation function of clusters identified in upcoming thermal SZ effect surveys. We then compute the expected fraction of close pairs of...

Self-similar cosmological expansion of collisional gas (2002)

Chuzhoy, Leonid, Nusser, Adi

We derive similarity solutions for the expansion of negative initial density perturbations \delta M/M \propto r^-s (s>0) in an Einstein-de Sitter universe filled with collisional baryonic gas and...

Peculiar Velocity Reconstruction with Fast Action Method: Tests on Mock Redshift Surveys (2001)

Branchini, Enzo, Eldar, Amiram, Nusser, Adi

We present extensive tests of the Fast Action Method (FAM) for recovering the past orbits of mass tracers in an expanding universe from their redshift-space coordinates at the present epoch. The...

Modified Newtonian Dynamics of Large Scale Structure (2001)

Nusser, Adi

We examine the implications of Modified Newtonian Dynamics (MOND) on the large scale structure in a Friedmann-Robertson-Walker universe. We employ a ``Jeans swindle'' to write a MOND-type...

Polarization of the Cosmic Microwave Background from Non-Uniform Reionization (2001)

Liu, Guo-Chin, Sugiyama, Naoshi, Benson, Andrew J., Lacey, C. G., Nusser, Adi

We study the signal in the Cosmic Microwave Background (CMB) polarization anisotropy resulting from patchy reionization. It is well known that the primordial polarization of the CMB is very sensitive...

Self-similar spherical collapse with non-radial motions (2000)

Nusser, Adi

We derive the asymptotic mass profile near the collapse center of an initial spherical density perturbation, $\delta \propto M^{-\epsilon}$, of collision-less particles with non-radial motions. We...

Comparison of the ENEAR Peculiar Velocities with the PSCz Gravity Field (2000)

Nusser, Adi, Da Costa, Luiz N., Branchini, Enzo, Bernardi, Mariangela, Alonso, M. V., Wegner, Gary, ...

We present a comparison between the peculiar velocity field measured from the ENEAR all-sky $D_n-\sigma$ catalog and that derived from the galaxy distribution of the IRAS PSCz redshift survey. The...

Self-similar collapse of collisional gas in an expanding Universe (2000)

Chuzhoy, Leonid, Nusser, Adi

Similarity solutions are found for the adiabatic collapse of density perturbations $\delta M/M \propto r^{-s}$ $(s>0)$ in a flat universe containing collisional gas only. The solutions are obtained...

Non-uniform reionization by galaxies and its effect on the cosmic microwave backgroun (2000)

Benson, A. J., Nusser, Adi, Sugiyama, Naoshi, Lacey, C. G.

We present predictions for the reionization of the intergalactic medium by stars in high-redshift galaxies. We calculate ionizing luminosities of galaxies, including the effects of absorption by...

Analytic solutions for coupled linear perturbations (2000)

Nusser, Adi

Analytic solutions for the evolution of cosmological linear density perturbations in the baryonic gas and collisionless dark matter are derived. The solutions are expressed in a closed form in terms...

Large scale motions in superclusters: their imprint in the CMB (1999)

Diaferio, Antonaldo, Sunyaev, Rashid A., Nusser, Adi

We identify high density regions of supercluster size in high resolution N-body simulations of a representative volume of three Cold Dark Matter Universes. By assuming that (1) the density and...

The Ly-alpha forest in a truncated hierarchical structure formation (1999)

Nusser, Adi, Lahav, Ofer

The Ly-alpha forest provides important constraints on the smoothness of the universe on large scales. We calculate the flux distribution along line-of-sight to quasars in a universe made of randomly...

On the least action principle in cosmology (1999)

Nusser, Adi, Branchini, Enzo

Given the present distribution of mass tracing objects in an expanding universe, we develop and test a fast method for recovering their past orbits using the least action principle. In this method,...

The amplitude of mass density fluctuations at $z\approx 3.25$ from the Ly-alpha forest of Q1422+231 (1999)

Nusser, Adi, Haehnelt, Martin

The real-space optical depth distribution along the line of sight to the QSO Q1422+231 is recovered from two HIRES spectra. The first two moments of the truncated optical depth distribution are used...

On the vorticity of flow in redshift space (1999)

Chodorowski, Michal, Nusser, Adi

Given an irrotational (vorticity free) velocity field in real space, we prove that, in the distant observer limit and in the absence of multi-valued zones, the associated velocity field in redshift...

A first step towards a direct inversion of the Lyman forest in QSO spectra (1998)

Nusser, Adi, Haehnelt, Martin

A method for the recovery of the real space line-of-sight mass density field from Lyman absorption in QSO spectra is presented. The method makes use of a Lucy-type algorithm for the recovery of the...

Mass growth and density profiles of dark matter halos in hierarchical clustering (1998)

Nusser, Adi, Sheth, Ravi

We develop a model for the growth of dark matter halos and use it to study their evolved density profiles. In this model, halos are spherical and form by quiescent accretion of matter in clumps,...

Recovery of the Cosmological Peculiar Velocity from the Density Field in the Weakly Nonlinear Regime (1998)

Chodorowski, Michal, Lokas, Ewa, Pollo, Agnieszka, Nusser, Adi

Using third-order perturbation theory, we derive a relation between the mean divergence of the peculiar velocity given density and the density itself. Our calculations assume Gaussian initial...

Comparison of the SFI Peculiar Velocities with the IRAS 1.2 Jy Gravity Field (1997)

Da Costa, Luiz N., Nusser, Adi, Freudling, Wolfram, Giovanelli, Riccardo, Haynes, Martha P., Salzer, John J., ...

We present a comparison between the peculiar velocity fields measured from the SFI all-sky Sbc-Sc Tully-Fisher catalog and that derived from the \iras 1.2 Jy redshift survey galaxy distribution. The...

The $\Omega$ Dependence in the Equations of Motion (1997)

Nusser, Adi, Colberg, Jörg M.

We show that the equations of motion governing the evolution of a collisionless gravitating system of particles in an expanding universe can be cast in a form which is almost independent of the...

Comparison of Velocity and Gravity Fields: The Mark III Tully-Fisher Catalog Versus the IRAS 1.2 Jy Survey (1996)

Davis, Marc, Nusser, Adi, Willick, Jeff

We consider a measure of the peculiar velocity field derived from the Mark III compilation of 2900 spiral galaxies (Willick \etal 1996b), using an analysis that is substantially free of bias (Nusser...

Galaxy Formation and Large-Scale Bias (1995)

Kauffmann, Guinevere, Nusser, Adi, Steinmetz, Matthias

We outline a simple approach to understanding the physical origin of bias in the distribution of galaxies relative to that of dark matter. The first step is to specify how collapsed, virialized halos...

INDICATIONS OF DARK MATTER DERIVED FROM LARGE SCALE FLOWS (1995)

Davis, Marc, Nusser, Adi

Recent progress in the measurement of relative distances to galaxies has been quite substantial, and catalogs of 3000 galaxies with distances are soon to become available. The peculiar {\it velocity}...

Estimation of Peculiar Velocity from the Inverse Tully-Fisher Relation (1994)

Nusser, Adi, Davis, Marc

We present a method for deriving a smoothed estimate of the peculiar velocity field of a set of galaxies with measured circular velocities $\eta\equiv {\rm log} \Delta v$ and apparent magnitudes $m$....

Evolution of One-Point Distributions from Gaussian Initial Fluctuations (1993)

Kofman, Lev, Bertschinger, Edmund, Gelb, James M., Nusser, Adi, Dekel, Avishai

We study the quasilinear evolution of the one-point probability density functions (PDFs) of the smoothed density and velocity fields in a cosmological gravitating system beginning with Gaussian...

On the Prediction of Velocity Fields from Redshift Space Galaxy Samples (1993)

Nusser, Adi, Davis, Marc

We present a new method for recovering the underlying velocity field from an observed distribution of galaxies in redshift space. The method is based on a kinematic Zel'dovich relation between the...