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Related papers: Orbit-based dynamical models of the Sculptor dSph …

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We construct axisymmetric Schwarzschild models to measure the mass profile of the local group dwarf galaxy Fornax. These models require no assumptions to be made about the orbital anisotropy of the stars, as is the case for commonly used…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 John Jardel , Karl Gebhardt

Stellar evolution models require initial isotopic abundance sets as input, but these abundances are incomplete outside the solar neighborhood, are challenging to infer from elemental observations, and are galaxy specific. Compositions…

Astrophysics of Galaxies · Physics 2021-07-22 Kanishk Pandey , Christopher West

Aims: We aim to compute the binary fraction of "classical" dwarf spheroidal galaxies (dSphs) that are satellites of the Milky Way (MW). This value can offer insights into the binary fraction in environments that are less dense and more…

A new family of self-consistent DF-based models of stellar systems is explored. The stellar component of the models is described by a distribution function (DF) depending on the action integrals, previously used to model the Fornax dwarf…

Astrophysics of Galaxies · Physics 2019-06-26 Raffaele Pascale , James Binney , Carlo Nipoti , Lorenzo Posti

We present here a detailed study of the Sculptor dSph galaxy red giant branch (RGB) and horizontal branch (HB) morphology, combining new near-infrared photometry from CIRSI, with optical data from the ESO WFI. For a Sculptor-like old and…

Astrophysics · Physics 2014-10-13 C. Babusiaux , G. Gilmore , M. Irwin

We present an innovative approach to the methodology of dynamical modelling, allowing practical reconstruction of the underlying dark matter mass without assuming both the density and anisotropy functions. With this, the mass-anisotropy…

We use both N-body simulations and integration in fixed potentials to explore the stability and the long-term secular evolution of self-consistent, equilibrium, non-rotating, triaxial spheroidal galactic models. More specifically, we…

Astrophysics of Galaxies · Physics 2015-06-03 E. Vasiliev , E. Athanassoula

Precise measurements of mass in dark matter dominated dwarf spheroidal galaxies are of great importance for testing the theories of structure formation. We use $N$-body simulations of the tidal evolution of a dwarf galaxy orbiting the Milky…

Astrophysics of Galaxies · Physics 2014-08-25 Klaudia Kowalczyk , Ewa L. Lokas

The results of a wide-field survey of the Sculptor dwarf spheroidal galaxy are presented. Our aims were to obtain an accurate map of the outer structure of Sculptor, and to determine the level of interaction between this system and the…

Astrophysics · Physics 2008-11-26 Matthew G. Coleman , G. S. Da Costa , Joss Bland-Hawthorn

An extension of Schwarzschild's galaxy-building technique is presented that, for the first time, enables one to build Schwarzschild models with known distribution functions (DFs). The new extension makes it possible to combine a DF that…

Astrophysics · Physics 2009-10-31 Ralf M. Hafner , N. Wyn Evans , Walter Dehnen , James Binney

We present an implementation of the Schwarzschild orbit superposition method which can be used for constructing self-consistent equilibrium models of barred or non-barred disc galaxies, or of elliptical galaxies with figure rotation. This…

Astrophysics of Galaxies · Physics 2015-05-14 Eugene Vasiliev , E. Athanassoula

Tremendous progress has been made recently in modelling the morphology and kinematics of centers of galaxies. Increasingly realistic models are built for central bar, bulge, nucleus and black hole of galaxies, including our own. The newly…

Astrophysics · Physics 2009-10-31 HongSheng Zhao

We investigate the mass distributions within eight classical Milky Way dwarf spheroidal galaxies (MW dSphs) using an equilibrium Jeans analysis and we compare our results to the mass distributions predicted for subhalos in dissipationless…

Cosmology and Nongalactic Astrophysics · Physics 2012-03-21 Joe Wolf , James S. Bullock

(ABRIDGED) We present a new Schwarzschild orbit-superposition code designed to model discrete datasets composed of velocities of individual kinematic tracers in a dynamical system. This constitutes an extension of previous implementations…

Astrophysics · Physics 2009-11-13 Julio Chanamé , Jan Kleyna , Roeland van der Marel

We use controlled $N$-body experiments to study the dynamical evolution of dwarf spheroidal galaxies (dSphs) embedded in dark-matter (DM) haloes containing a large population of dark subhaloes. We show that stellar orbits subject to…

Astrophysics of Galaxies · Physics 2026-04-28 Jorge Peñarrubia , Ethan O. Nadler

Dwarf spheroidal (dSph) galaxies are considered the basic building blocks of the galaxy formation process in the LCDM (Lambda Cold Dark Matter) hierarchical cosmological model. These galaxies are believed to be the most dark matter (DM)…

Astrophysics of Galaxies · Physics 2015-06-16 P. Assmann , M. Fellhauer , M. I. Wilkinson , R. Smith , M. Blaña

By manipulating the spherical Jeans equation, Wolf et al. (2010) show that the mass enclosed within the 3D deprojected half-light radius r_1/2 can be determined with only mild assumptions about the spatial variation of the stellar velocity…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Joe Wolf

We investigate the accuracy and precision of triaxial dynamical orbit models by fitting two dimensional mock observations of a realistic N-body merger simulation resembling a massive early-type galaxy with a supermassive black hole (SMBH).…

Astrophysics of Galaxies · Physics 2022-12-21 B. Neureiter , S. de Nicola , J. Thomas , R. Saglia , R. Bender , A. Rantala

We present a method for fitting orbit-superposition models to the kinematics of discrete stellar systems when the available stellar sample has been filtered by a known selection function. The fitting method can be applied to any model in…

Astrophysics of Galaxies · Physics 2019-01-23 John Magorrian

Assuming spherical symmetry and dynamical equilibrium within a given gravitational potential, a dwarf spheroidal (dSph) galaxy's globally averaged stellar velocity dispersion depends entirely on the shape of its stellar density profile.…

Astrophysics of Galaxies · Physics 2026-02-13 Sofia L. Splawska , Raphaël Errani , Jorge Peñarrubia , Matthew G. Walker