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Related papers: Testing Dark Matter with Generative Models for Ext…

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Terrestrial searches for the conversion of dark matter axions or axion-like particles into photons inside magnetic fields are sensitive to the phase space structure of the local Milky Way halo. We simulate signals in a hypothetical future…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-29 Ciaran A. J. O'Hare , Anne M. Green

Mysterious dark matter constitutes about 85% of all mass in the Universe. Clustering of dark matter plays the dominant role in the formation of all observed structures on scales from a fraction to a few hundreds of Mega-parsecs. Galaxies…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-26 Nesar S. Ramachandra , Sergei F. Shandarin

Tidal streams are a powerful probe of the Milky Way (MW) potential shape. In this paper, we introduce a simple test particle method to fit stream data, using a Markov Chain Monte Carlo technique to marginalise over uncertainties in the…

Astrophysics of Galaxies · Physics 2015-06-16 H. Lux , J. I. Read , G. Lake , K. V. Johnston

We investigate the formation of spherical cosmological structures following both dark matter and gas components. We focus on the dynamical aspect of the collapse assuming an adiabatic, $\gamma = 5/3$, fully ionized primordial plasma. We use…

Astrophysics · Physics 2009-10-30 Jean-Pierre CHIEZE , Romain Teyssier , Jean-Michel Alimi

We present a generative probabilistic model for a tidal stream and demonstrate how this model is used to constrain the Galactic potential. The model takes advantage of the simple structure of a stream in angle and frequency space for the…

Astrophysics of Galaxies · Physics 2015-06-18 Jason L. Sanders

The scale radius of dark matter halos is a critical parameter for specifying the density distribution of dark matter, and is therefore a fundamental parameter for modeling galaxies. We develop here a novel, observationally motivated probe…

Cosmology and Nongalactic Astrophysics · Physics 2011-12-08 Sukanya Chakrabarti

In this paper we discuss a method for the generation of mock tidal streams. Using an ensemble of simulations in an isochrone potential where the actions and frequencies are known, we derive an empirical recipe for the evolving satellite…

Astrophysics of Galaxies · Physics 2015-07-15 Mark A. Fardal , Shuiyao Huang , Martin D. Weinberg

The GD-1 stellar stream exhibits spur and gap structures that may result from a close encounter with a dense substructure. When interpreted as a dark matter subhalo, the perturber is denser than predicted in the standard cold dark matter…

Astrophysics of Galaxies · Physics 2024-12-31 Xingyu Zhang , Hai-Bo Yu , Daneng Yang , Ethan O. Nadler

In this work, we explore the idea that substructures like stellar clusters could be formed from the tidal stream produced in galactic minor mergers. We use $N$-body and SPH simulations of satellite galaxies interacting with a larger galaxy.…

Astrophysics of Galaxies · Physics 2020-01-15 D. A. Noreña , J. C. Muñoz-Cuartas , L. F. Quiroga , N. Libeskind

To maximize the amount of information extracted from cosmological datasets, simulations that accurately represent these observations are necessary. However, traditional simulations that evolve particles under gravity by estimating…

We use high-resolution N-body simulations to follow the formation and evolution of tidal streams associated to dwarf spheroidal galaxies (dSphs). The dSph models are embedded in dark matter (DM) haloes with either a centrally-divergent…

Astrophysics of Galaxies · Physics 2016-02-22 Raphaël Errani , Jorge Peñarrubia , Giuseppe Tormen

Stellar streams are particularly sensitive probes of the mass distribution of galaxies. In this work, we focus on the Helmi Streams, the remnants of an accreted dwarf galaxy orbiting the inner Milky Way. We examine in depth their peculiar…

Astrophysics of Galaxies · Physics 2024-11-20 Hanneke C. Woudenberg , Amina Helmi

There is mounting evidence that a self-consistent model for particle cold dark matter has to take into consideration spatial inhomogeneities on sub-galactic scales seen, for instance, in high-resolution N-body simulations of structure…

Astrophysics · Physics 2009-10-31 Lars Bergstrom , Joakim Edsjo , Christofer Gunnarsson

Full ray-tracing maps of gravitational lensing, constructed from N-Body simulations, represent a fundamental tool to interpret present and future weak lensing data. However the limitation of computational resources and storage capabilities…

In a serie of three papers, the dynamical interplay between environments and dark matter haloes is investigated, while focussing on the dynamical flows through their virial sphere. Our method relies on both cosmological simulations, to…

Astrophysics · Physics 2008-11-26 Dominique Aubert , Christophe Pichon

Stellar streams retain a memory of their gravitational interactions with small-scale perturbations. While perturbative models for streams have been formulated in action-angle coordinates, a direct transformation to these coordinates is only…

We explore the stellar mass density and colour profiles of 118 low redshift, massive, central galaxies, selected to have assembled 90 percent of their stellar mass 6 Gyr ago, finding evidence of the minor merger activity expected to be the…

Astrophysics of Galaxies · Physics 2023-01-10 Thomas M. Jackson , Anna Pasquali , Francesco La Barbera , Surhud More , Eva K. Grebel

The future astronomical imaging surveys are set to provide precise constraints on cosmological parameters, such as dark energy. However, production of synthetic data for these surveys, to test and validate analysis methods, suffers from a…

In cold dark matter cosmological models, structures form and grow by merging of smaller units. Numerical simulations have shown that such merging is incomplete; the inner cores of halos survive and orbit as "subhalos" within their hosts.…

Astrophysics · Physics 2010-04-06 J. Diemand , M. Kuhlen , P. Madau , M. Zemp , B. Moore , D. Potter , J. Stadel

We focus on how astrometric surveys might be exploited for the study of Galactic halo substructure originating from the disruption of satellite systems. The Sagittarius (Sgr) dwarf spheroidal tidal stream provides a useful template to…

Astrophysics · Physics 2007-05-23 Steven R. Majewski , Allyson A. Polak , David R. Law , Helio J. Rocha-Pinto