325 citations · 2.8k across the 72 of their papers we have counts for
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The anatomy of Leo I: how tidal tails affect the kinematics
Ewa L. Lokas, Jaroslaw Klimentowski, Stelios Kazantzidis +1
We model the recently published kinematic data set for Leo I dSph galaxy by fitting the solutions of the Jeans equations to the velocity dispersion and kurtosis profiles measured f…
Tidal evolution of disky dwarf galaxies in the Milky Way potential: the formation of dwarf spheroidals
Jaroslaw Klimentowski, Ewa L. Lokas, Stelios Kazantzidis +2
We conduct high-resolution collisionless N-body simulations to investigate the tidal evolution of dwarf galaxies on an eccentric orbit in the Milky Way (MW) potential. The dwarfs o…
The distribution function of dark matter in massive haloes
Radoslaw Wojtak, Ewa L. Lokas, Gary A. Mamon +3
We study the distribution function (DF) of dark matter particles in haloes of mass range 10^{14}--10^{15}\Msun. In the numerical part of this work we measure the DF for a sample of…
Mass modelling of Abell 2634: avoiding the interloper bias
Radoslaw Wojtak, Ewa L. Lokas
Using an example of the Abell 2634 galaxy cluster we discuss the effect of contamination of kinematic data by interlopers and its impact on mass modelling. The cluster data reveal…
The effect of unbound stars on the mass modelling of the Fornax dwarf
Ewa L. Lokas, Jaroslaw Klimentowski, Radoslaw Wojtak
We discuss how different approaches to selecting member stars in kinematic samples of dwarf spheroidal galaxies affect the estimates of their mass and anisotropy of stellar orbits.…
Mass modelling of galaxy clusters via velocity moments
Ewa L. Lokas, Radoslaw Wojtak, Gary A. Mamon +1
We summarize the method of mass modelling of galaxy clusters based on reproducing the dispersion and kurtosis of the projected velocity distribution of galaxies. The models are par…
NGC 5128 as an isotropic rotator
Ewa L. Lokas
NGC 5128 is a well-studied elliptical galaxy with an excellent kinematic data set for planetary nebulae which has been modelled up till now only by solving the Jeans equation for s…
Mass modelling of dwarf spheroidal galaxies: the effect of unbound stars from tidal tails and the Milky Way
Jaroslaw Klimentowski, Ewa L. Lokas, Stelios Kazantzidis +3
We study the origin and properties of the population of unbound stars in the kinematic samples of dwarf spheroidal galaxies. For this purpose we have run a high resolution N-body s…
The importance of interloper removal in galaxy clusters: saving more objects for the Jeans analysis
Radoslaw Wojtak, Ewa L. Lokas
We study the effect of contamination by interlopers in kinematic samples of galaxy clusters. We demonstrate that without the proper removal of interlopers the inferred parameters o…
Interloper treatment in dynamical modelling of galaxy clusters
Radoslaw Wojtak, Ewa L. Lokas, Gary A. Mamon +3
The aim of this paper is to study the efficiency of different approaches to interloper treatment in dynamical modelling of galaxy clusters. Using cosmological N-body simulation of…
Kinematical and Dynamical Modeling of Elliptical Galaxies
G. A. Mamon, E. Lokas, A. Dekel +2
Elements of kinematical and dynamical modeling of elliptical galaxies (Es) are presented. In projection, NFW models resemble Sersic models, but with a very narrow range of shapes (…
Mass distribution in nearby Abell clusters
Ewa L. Lokas, Radoslaw Wojtak, Stefan Gottloeber +2
We study the mass distribution in six nearby (z<0.06) relaxed Abell clusters of galaxies A0262, A0496, A1060, A2199, A3158 and A3558. Given the dominance of dark matter in galaxy c…
The Draco dwarf in CDM and MOND
Ewa L. Lokas, Gary A. Mamon, Francisco Prada
We present interpretations of the line-of-sight velocity distribution of stars in the Draco dwarf spheroidal galaxy in terms of CDM and MOND assuming constant mass-to-light ratio a…
Velocity moments of dark matter haloes
Radoslaw Wojtak, Ewa L. Lokas, Stefan Gottloeber +1
Using cosmological N-body simulations we study the line-of-sight velocity distribution of dark matter haloes focusing on the lowest-order even moments, dispersion and kurtosis, and…
The complex velocity distribution of galaxies in Abell 1689: implications for mass modelling
Ewa L. Lokas, Francisco Prada, Radoslaw Wojtak +2
The Abell 1689 galaxy cluster has recently become a subject of intensive study. Thanks to its intermediate redshift (z=0.183) its mass distribution can be reconstructed using numer…
Radial velocity moments of dark matter haloes
Radoslaw Wojtak, Ewa L. Lokas, Stefan Gottloeber +1
Using cosmological N-body simulations we study the radial velocity distribution in dark matter haloes focusing on the lowest-order even moments, dispersion and kurtosis. We determi…
Dark matter distribution in the Draco dwarf from velocity moments
Ewa L. Lokas, Gary A. Mamon, Francisco Prada
We study the distribution of dark matter in the Draco dwarf spheroidal galaxy by modelling the moments of the line-of-sight velocity distribution of stars obtained from new velocit…
Cluster mass functions in the quintessential Universe
Ewa L. Lokas, Paul Bode, Yehuda Hoffman
We use -body simulations to measure mass functions in flat cosmological models with quintessence characterized by constant with , -2/3 and -1/2. The results are compar…
How reliable is the kinematical evidence for dark matter: the effects of non-sphericity, substructure and streaming motions
Teresa Sanchis, Ewa L. Lokas, Gary A. Mamon
Using cosmological -body simulations of dark matter haloes, we study the effects of non-sphericity, substructure and streaming motions in reproducing the structure and internal…
The structure of voids
Stefan Gottloeber, Ewa Lokas, Anatoly Klypin +1
Using high resolution N-body simulations we address the problem of emptiness of giant 20 Mpc/h diameter voids found in the distribution of bright galaxies. Are the voids filled by…
Dark matter distribution in the Coma cluster from galaxy kinematics: breaking the mass-anisotropy degeneracy
Ewa L. Lokas, Gary A. Mamon
We study velocity moments of elliptical galaxies in the Coma cluster using Jeans equations. The dark matter distribution in the cluster is modelled by a generalised formula based u…
Structure formation in the quintessential Universe
Ewa L. Lokas
I review the main characteristics of structure formation in the quintessential Universe. Assuming equation of state w=p/\varrho=$const I provide a brief description of the backgrou…
Dark matter distribution in dwarf spheroidal galaxies
Ewa L. Lokas
We study the distribution of dark matter in dwarf spheroidal galaxies by modelling the moments of their line-of-sight velocity distributions. We discuss different dark matter densi…
Nonlinear evolution of spherical perturbation in a non-flat Universe with cosmological constant
Ewa L. Lokas, Yehuda Hoffman
We generalize the spherical collapse model for the formation of bound objects to apply in a Universe with arbitrary positive cosmological constant. We calculate the critical condit…