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Related papers: Action-based dynamical models of M31-like galaxies

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Dynamical models are used to study dark matter (DM) in galaxies, how galaxies assemble through mergers, and to test galaxy formation models. Despite its widespread use, there has been no systematic study quantifying how much information can…

Astrophysics of Galaxies · Physics 2025-11-14 Paula Gherghinescu , Eugene Vasiliev , Payel Das , Justin Read

We develop a flexible set of action-based distribution functions (DFs) for stellar haloes. The DFs have five free parameters, controlling the inner and outer density slope, break radius, flattening and anisotropy respectively. The DFs…

Astrophysics of Galaxies · Physics 2015-09-30 A. A. Williams , N. W. Evans

We present new dynamical models of dwarf spheroidal galaxies (dSphs) in which both the stellar component and the dark halo are described by analytic distribution functions that depend on the action integrals. In their most general form…

Astrophysics of Galaxies · Physics 2018-08-01 Raffaele Pascale , Lorenzo Posti , Carlo Nipoti , James Binney

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 provide a family of action-based distribution functions (DFs) for the double-power law family of densities often used to model galaxies. The DF itself is a double-power law in combinations of the actions, and reduces to the known limits…

Astrophysics of Galaxies · Physics 2015-06-23 A. A. Williams , N. W. Evans

We construct a new family of models of our Galaxy in which dark matter and disc stars are both represented by distribution functions that are analytic functions of the action integrals of motion. The potential that is self-consistently…

Astrophysics of Galaxies · Physics 2016-12-14 David R. Cole , James Binney

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 relaxed haloes formed in the simulation of a standard…

We estimate the 3D density profile of the Galactic dark matter (DM) halo within $r \lesssim 30$ kpc from the Galactic centre by using the astrometric data for halo RR Lyrae stars from Gaia DR2. We model both the stellar halo distribution…

Astrophysics of Galaxies · Physics 2021-10-20 Kohei Hattori , Monica Valluri , Eugene Vasiliev

We use maximum entropy arguments to derive the phase space distribution of a virialized dark matter halo. Our distribution function gives an improved representation of the end product of violent relaxation. This is achieved by incorporating…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Andrew Pontzen , Fabio Governato

Starting from the hypothesis that the Galaxy's dark halo responded adiabatically to the infall of baryons, we have constructed a self-consistent dynamical model of the Galaxy that satisfies a large number of observations, including…

Astrophysics of Galaxies · Physics 2015-10-28 James Binney , Tilmann Piffl

We present a rigorous and practical way of constraining the Galactic potential based on the phase-space information for many individual stars. Such an approach is needed to dynamically model the data from ongoing spectroscopic surveys of…

Astrophysics of Galaxies · Physics 2015-07-10 Yuan-Sen Ting , Hans-Walter Rix , Jo Bovy , Glenn van de Ven

Galaxy kinematics and gravitational lensing are two complementary ways to constrain the distribution of dark matter on galaxy scales. The typical dark matter density profiles adopted in dynamical studies cannot easily be adopted in lensing…

Astrophysics of Galaxies · Physics 2021-03-17 Maarten Baes , Peter Camps

We present a new method to construct fully self-consistent equilibrium models of multi-component disc galaxies similar to the Milky Way. We define distribution functions for the stellar disc and dark halo that depend on phase space position…

Astrophysics of Galaxies · Physics 2015-07-03 T. Piffl , Z. Penoyre , J. Binney

Stellar mass distribution in M31 is estimated using optical and infrared imaging data. Combining the derived stellar mass model with various kinematical data, properties of the DM halo of the galaxy are constrained. SDSS observations…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 A. Tamm , E. Tempel , P. Tenjes , O. Tihhonova , T. Tuvikene

We present an approach to the design of distribution functions that depend on the phase-space coordinates through the action integrals. The approach makes it easy to construct a dynamical model of a given stellar component. We illustrate…

Astrophysics of Galaxies · Physics 2015-06-23 Lorenzo Posti , James Binney , Carlo Nipoti , Luca Ciotti

A simple analytical model for describing inner parts of dark matter halo is considered. It is assumed that dark matter density is power-law. The model deals with dark matter distribution function in phase space of adiabatic invariants…

Astrophysics · Physics 2017-04-24 E. Vasiliev

We explore the viability of scalar field dark matter halo models through the rotation curve analysis of the Andromeda galaxy (M31), taking into account a realistic description of its baryonic structure. The mass model includes a stellar…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-28 Gulnara Suliyeva , Kuantay Boshkayev , Talgar Konysbayev , Yergali Kurmanov , Guldana Rabigulova

I present a new method of deriving the shape of the dark matter (DM) halos of spiral galaxies. The method relies on the comparison of model predictions with high spectral and spatial resolution HI observations of the gas layer. The…

Astrophysics · Physics 2009-10-28 Rob P. Olling

N-body simulations and analytical calculations of the gravitational collapse in an expanding universe predict that halos should form with a diverging inner density profile, the cusp. There are some observational indications that the dark…

Astrophysics · Physics 2009-11-06 Amr El-Zant , Isaac Shlosman , Yehuda Hoffman

We propose that angular momentum transfer from the baryons to the Dark Matter (DM) during the early stages of galaxy formation can flatten the halo inner density profile and modify the halo dynamics. We compute the phase-space distribution…

Astrophysics · Physics 2011-02-11 Chiara Tonini , Andrea Lapi , Paolo Salucci
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