Klaus Dolag

The onset of star formation in primordial haloes (2009)

Maio, Umberto, Ciardi, Benedetta, Yoshida, Naoki, Dolag, Klaus, Tornatore, Luca

Star formation remains an unsolved problem in astrophysics. Numerical studies of large-scale structure simulations cannot resolve the whole process and their approach usually assumes that only gas...

X-MAS2: Study Systematics on the ICM Metallicity Measurements (2008)

Rasia, Elena, Mazzotta, Pasquale, Bourdin, Herve, Borgani, Stefano, Tornatore, Luca, Ettori, Stefano, ...

X-ray measurements of the intracluster medium metallicity are becoming more and more frequent due to the availability of powerful X-ray telescopes with excellent spatial and spectral resolutions. The...

On the dynamical origin of the ICM metallicity evolution (2008)

Cora, Sofia A., Tornatore, Luca, Tozzi, Paolo, Dolag, Klaus

We present a study on the origin of the metallicity evolution of the intra-cluster medium (ICM) by applying a semi-analytic model of galaxy formation to N-body/SPH (smoothed particle hydrodynamic)...

Ultra High Resolution study of Turbulence in a Galaxy Cluster (2008)

Klaus Dolag

Abstract. ± Implementing a new formulation for the artificial viscosity in the cosmological SPH code GADGET-2 to we performed a set of high resolution simulations of forming galaxy clusters. We find...

Chemical enrichment of galaxy clusters from hydrodynamical simulations (2007)

Tornatore, Luca, Borgani, Stefano, Dolag, Klaus, Matteucci, Francesca

We present cosmological hydrodynamical simulations of galaxy clusters aimed at studying the process of metal enrichment of the intra-cluster medium (ICM). These simulations have been performed by...

The Effect of Primordial Non--Gaussianity on the Topology of Large-Scale Structure (2007)

Hikage, Chiaki, Coles, Peter, Grossi, Margherita, Moscardini, Lauro, Dolag, Klaus, Branchini, Enzo, ...

We study the effect of primordial non--Gaussianity on the development of large-scale cosmic structure using high-resolution N-body simulations. In particular, we focus on the topological properties...

Realistic simulations of gravitational lensing by galaxy clusters: extracting arc parameters from mock DUNE images (2007)

Meneghetti, Massimo, Melchior, Peter, Grazian, Andrea, De Lucia, Gabriella, Dolag, Klaus, Bartelmann, Matthias, ...

We present a newly developed code that allows simulations of optical observations of galaxy fields with a variety of instruments. The code incorporates gravitational lensing effects and is targetted...

Early structure formation in quintessence models and its implications for cosmic reionization from first stars (2007)

Maio, Umberto, Dolag, Klaus, Meneghetti, Massimo, Moscardini, Lauro, Yoshida, Naoki, Baccigalupi, Carlo, ...

We present the first hydrodynamic N-body simulations of primordial gas clouds responsible for the reionisation process in dark energy cosmologies. We compare the cosmological constant scenario with a...

Hot and cooled baryons in smoothed particle hydrodynamic simulations of galaxy clusters: physics and numerics (2007)

Borgani, Stefano, Dolag, Klaus, Murante, Giuseppe, Cheng, L.M., Springel, Volker, Diaferio, Antonaldo, ...

We discuss an extended set of Tree+SPH simulations of galaxy clusters, with the goal of investigating the interplay between numerical resolution effects and star-formation/feedback processes. The...

Properties of the galaxy population in hydrodynamical simulations of clusters (2007)

Saro, Alexandro, Borgani, Stefano, Tornatore, Luca, Dolag, Klaus, Murante, Giuseppe, Biviano, Andrea, ...

We present a study of the galaxy population predicted by hydrodynamical simulations for a set of 19 galaxy clusters based on the GADGET-2 Tree+SPH code. These simulations include gas cooling, star...

Metal and molecule cooling in simulations of structure formation (2007)

Maio, Umberto, Dolag, Klaus, Ciardi, Benedetta, Tornatore, Luca

Cooling is the main process leading to the condensation of gas in the dark matter potential wells and consequently to star and structure formation. In a metal-free environment, the main available...

Testing the reliability of weak lensing cluster detections (2007)

Pace, Francesco, Maturi, Matteo, Meneghetti, Massimo, Bartelmann, Matthias, Moscardini, Lauro, Dolag, Klaus

We study the reliability of dark-matter halo detections with three different linear filters applied to weak-lensing data. We use ray-tracing in the multiple lens-plane approximation through a large...

Simulating cosmic rays in clusters of galaxies - I. Effects on the Sunyaev-Zel'dovich effect and the X-ray emission (2006)

Pfrommer, Christoph, Ensslin, Torsten A., Springel, Volker, Jubelgas, Martin, Dolag, Klaus

We performed high-resolution simulations of a sample of 14 galaxy clusters that span a mass range from 5 x 10^13 M_solar/h to 2 x 10^15 M_solar/h to study the effects of cosmic rays (CRs) on thermal...

Radial profile and log-normal fluctuations of intra-cluster medium as an origin of systematic bias of spectroscopic temperature (2006)

Kawahara, Hajime, Suto, Yasushi, Kitayama, Tetsu, Sasaki, Shin, Shimizu, Mamoru, Rasia, Elena, ...

The origin of the recently reported systematic bias in the spectroscopic temperature of galaxy clusters is investigated using cosmological hydrodynamical simulations. We find that the local...

Arc sensitivity to cluster ellipticity, asymmetries and substructures (2006)

Meneghetti, Massimo, Argazzi, Rodolfo, Pace, Francesco, Moscardini, Lauro, Dolag, Klaus, Bartelmann, Matthias, ...

We investigate how ellipticity, asymmetries and substructures separately affect the ability of galaxy clusters to produce strong lensing events, i.e. gravitational arcs, and how they influence the...

Simulating large-scale structure formation with magnetic fields (2006)

Dolag, Klaus

In the past, different works based on numerical simulations have been presented to explain magnetic fields (MFs) in the large scale structure and within galaxy clusters. In this review, I will...

A simulation pipeline for the Planck mission (2005)

Reinecke, Martin, Dolag, Klaus, Hell, Reinhard, Bartelmann, Matthias, Ensslin, Torsten

We describe an assembly of numerical tools to model the output data of the Planck satellite. These start with the generation of a CMB sky in a chosen cosmology, add in various foreground sources,...

The impact of gas physics on strong cluster lensing (2005)

Puchwein, Ewald, Bartelmann, Matthias, Dolag, Klaus, Meneghetti, Massimo

Previous studies of strong gravitational lensing by galaxy clusters neglected the potential impact of the intracluster gas. Here, we compare simulations of strong cluster lensing including gas...

Constrained Simulations of the Magnetic Field in the Local Universe and the Propagation of UHECRs (2004)

Dolag, Klaus, Grasso, Dario, Springel, Volker, Tkachev, Igor

We use simulations of LSS formation to study the build-up of magnetic fields (MFs) in the ICM. Our basic assumption is that cosmological MFs grow in a MHD amplification process driven by structure...

Constraints on Dark Energy Models from Galaxy Clusters with Multiple Arcs (2004)

Meneghetti, Massimo, Jain, Bhuvnesh, Bartelmann, Matthias, Dolag, Klaus

We make an exploratory study of how well dark energy models can be constrained using lensed arcs at different redshifts behind cluster lenses. Arcs trace the critical curves of clusters, and the...

Strong lensing by cluster-sized haloes in dark-energy cosmologies (2004)

Meneghetti, Massimo, Bartelmann, Matthias, Dolag, Klaus, Moscardini, Lauro, Perrotta, Francesca, Baccigalupi, Carlo, ...

We study the efficiency of numerically simulated galaxy clusters for producing strong gravitational lensing events in different dark-energy cosmologies with constant and time-variable equation of...

Numerical study of halo concentrations in dark-energy cosmologies (2004)

Dolag, Klaus, Bartelmann, Matthias, Perrotta, Francesca, Baccigalupi, Carlo, Moscardini, Lauro, Meneghetti, Massimo, ...

We study the concentration parameters, their mass dependence and redshift evolution, of dark-matter halos in different dark-energy cosmologies with constant and time-variable equation of state, and...

Mapping deflections of extragalactic Ultra-High Energy Cosmic Rays in magnetohydrodynamic simulations of the Local Universe (2003)

Dolag, Klaus, Grasso, Dario, Springel, Volker, Tkachev, Igor

We construct a map of deflections of ultra-high energy cosmic rays by extragalactic magnetic fields using a magneto-hydrodynamical simulation of cosmic structure formation that realistically...

Numerical study of halo concentrations in dark-energy cosmologies (2003)

Dolag, Klaus, Bartelmann, Matthias, Perrotta, Francesca, Baccigalupi, Carlo, Moscardini, Lauro, Meneghetti, Massimo, ...

We study the concentration parameters, their mass dependence and redshift evolution, of dark-matter halos in different dark-energy cosmologies with constant and time-variable equation of state, and...

Probing Intracluster Magnetic Fields with Cosmic Microwave Background Polarization (2002)

Ohno, Hiroshi, Takada, Masahiro, Dolag, Klaus, Bartelmann, Matthias, Sugiyama, Naoshi

Intracluster magnetic fields with $ \sim \mu G $ strength induce Faraday rotation on the cosmic microwave background (CMB) polarization. Measurements of this effect can potentially probe the detailed...

Evolution and structure of magnetic fields in simulated galaxy clusters (2002)

Dolag, Klaus, Bartelmann, Matthias, Lesch, Harald

We use cosmological magneto-hydrodynamic simulations to study the evolution of magnetic fields in galaxy clusters in two different cosmological models, a standard-CDM and a $\Lambda$-CDM model. We...

The Evolution of Magnetic Fields in Galaxy Clusters (2001)

Bartelmann, Matthias, Dolag, Klaus, Lesch, Harald

Cosmological simulations of magnetic fields in galaxy clusters show that remarkable agreement between simulations and observations of Faraday rotation and radio haloes can be achieved assuming that...

The temperature-mass relation in magnetized galaxy clusters (2001)

Dolag, Klaus, Evrard, August, Bartelmann, Matthias

We use cosmological, magneto-hydrodynamic simulations of galaxy clusters to quantify the dynamical importance of magnetic fields in these clusters. The set-up of initial magnetic field strengths at...

The effect of magnetic fields on the mass determination of clusters of galaxies (2000)

Dolag, Klaus, Schindler, Sabine

We test the effects of magnetic fields on the mass determination of galaxy clusters with the X-ray method. As this method takes into account only thermal pressure, additional non-thermal pressure...

Properties of Simulated Magnetized Galaxy Clusters (2000)

Dolag, Klaus

We study the evolution of magnetized clusters in a cosmological environment using magneto-hydro dynamical simulations. Large scale flows and merging of subclumps generate shear flows leading to...

Radio Halos of Galaxy Clusters from Hadronic Secondary Electron Injection in Realistic Magnetic Field Configurations (2000)

Dolag, Klaus, Ensslin, Torsten A.

We investigate the possibility that radio halos of clusters of galaxies are caused by synchrotron emission of cosmic ray electrons (CRe), which were produced by cosmic ray protons (CRp) interacting...

SPH simulations of magnetic fields in galaxy clusters (proceedings) (1999)

Dolag, Klaus, Bartelmann, Matthias, Lesch, Harald

We perform cosmological, hydrodynamic simulations of magnetic fields in galaxy clusters. The computational code combines the special-purpose hardware Grape for calculating gravitational interaction,...

SPH simulations of magnetic fields in galaxy clusters (1999)

Dolag, Klaus, Bartelmann, Matthias, Lesch, Harald

We perform cosmological, hydrodynamic simulations of magnetic fields in galaxy clusters. The computational code combines the special-purpose hardware Grape for calculating gravitational interaction,...

QSO-galaxy correlations due to weak lensing in arbitrary Friedmann-Lemaitre cosmologies (1997)

Dolag, Klaus, Bartelmann, Matthias

We calculate the angular cross-correlation function between background QSOs and foreground galaxies induced by the weak lensing effect of large-scale structures. Results are given for arbitrary...