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Related papers: Haloes gone MAD: The Halo-Finder Comparison Projec…

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We train graph neural networks on halo catalogues from Gadget N-body simulations to perform field-level likelihood-free inference of cosmological parameters. The catalogues contain $\lesssim$5,000 halos with masses $\gtrsim…

Several lines of evidence suggest that as dark matter haloes grow their scale radius increases, and that the density in their central region drops. Major mergers seem an obvious mechanism to explain both these phenomena, and the resulting…

Astrophysics of Galaxies · Physics 2019-05-28 Nicole E. Drakos , James E. Taylor , Anael Berrouet , Aaron S. G. Robotham , Chris Power

We study the phase-space structure of a dark-matter halo formed in a high resolution simulation of a Lambda CDM cosmology. Our goal is to quantify how much substructure is left over from the inhomogeneous growth of the halo, and how it may…

Astrophysics · Physics 2009-09-25 Amina Helmi , Simon D. M. White , Volker Springel

We test and present the application of the full rescaling method by Angulo & White (2010) to change the cosmology of halo catalogues in numerical simulations for cosmological parameter search using semi-analytic galaxy properties. We show…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Andrés N. Ruiz , Nelson D. Padilla , Mariano J. Domínguez , Sofía A. Cora

We investigate mass segregation in group and cluster environments by identifying galaxy analogues in high-resolution dark matter simulations. Subhalos identified by the AHF and ROCKSTAR halo finders have similar mass functions, independent…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-17 Gandhali D. Joshi , Laura C. Parker , James Wadsley

The detection of microlensing has opened the way for the development of new methods in galactic astronomy. This series of papers investigates what microlensing can teach us about the structure and shape of the dark halo. In this paper we…

Dark matter halos are typically defined as spheres that enclose some overdensity, but these sharp, somewhat arbitrary boundaries introduce non-physical artifacts such as backsplash halos, pseudo-evolution, and an incomplete accounting of…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-21 Ze'ev Vladimir , Calvin Osinga , Benedikt Diemer , Edgar M. Salazar , Eduardo Rozo

This work investigates a set of cosmological collisionless N-body simulations with featured power spectra of initial perturbations in the context of the core-cusp and satellites problems. On the studied power spectra some scales of…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-14 Vadim Semenov , Sergey Pilipenko , Andrei Doroshkevich , Vladimir Lukash , Elena Mikheeva

The identification of substructures within halos in cosmological hydrodynamical simulations is a fundamental step to identify the simulated counterparts of real objects, namely galaxies. For this reason, substructure finders play a crucial…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-04 Michela Esposito , Stefano Borgani , Giuseppe Murante

Shape measurements of galaxies and galaxy clusters are widespread in the analysis of cosmological simulations. But the limitations of those measurements have been poorly investigated. In this paper, we explain why the quality of the shape…

Astrophysics of Galaxies · Physics 2023-02-22 Moritz S. Fischer , Lucas M. Valenzuela

We present a method for computing the 6-dimensional coarse-grained phase-space density $f(x,v)$ in an N-body system, and derive its distribution function $v(f)$. The method is based on Delaunay tessellation, where $v(f)$ is obtained with an…

Astrophysics · Physics 2009-11-10 I. Arad , A. Dekel , A. Klypin

We perform for the first time high-resolution zoom-in re-simulations of individual halos in the context of the Multi-coupled Dark Energy (McDE) scenario, which is characterised by the existence of two distinct dark matter particle species…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-05 E. Garaldi , M. Baldi , L. Moscardini

We study the density profile and shape of the Galactic halo using deep multicolour images from the MENeaCS and CCCP projects, over 33 fields selected to avoid overlap with the Galactic plane. Using multicolour selection and PSF…

Astrophysics of Galaxies · Physics 2015-06-24 B. Pila-Díez , J. T. A. de Jong , K. Kuijken , R. F. J. van der Burg , H. Hoekstra

We perform a series of high-resolution N-body simulations designed to examine the density profiles of dark matter halos. From 12 simulated halos ranging the mass of $2\times10^{12}\sim 5\times10^{14} h^{-1}{\rm M_\odot}$ (represented by…

Astrophysics · Physics 2009-10-31 Y. P. Jing , Yasushi Suto

We develop a theoretical framework for describing the hierarchical structure of the phase space of cold dark matter haloes, due to gravitationally bound substructures. Because it includes the full hierarchy of the cold dark matter initial…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Niayesh Afshordi , Roya Mohayaee , Edmund Bertschinger

We provide new constraints on the connection between galaxies in the local universe, identified by the Sloan Digital Sky Survey (SDSS), and dark matter halos and their constituent substructures in the $\Lambda$CDM model using WMAP7…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-20 Rachel M. Reddick , Risa H. Wechsler , Jeremy L. Tinker , Peter S. Behroozi

We introduce Copernicus Complexio (COCO), a high-resolution cosmological N-body simulation of structure formation in the $\Lambda{\rm CDM}{}$ model. COCO follows an approximately spherical region of radius $\sim 17.4h^{-1}\,{\rm Mpc}$…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-17 Wojciech A. Hellwing , Carlos S. Frenk , Marius Cautun , Sownak Bose , John Helly , Adrian Jenkins , Till Sawala , Maciej Cytowski

Aims. Several kinematic and chemical substructures have been recently found amongst Milky Way halo stars with retrograde motions. It is currently unclear how these various structures are related to each other. This Letter aims to shed light…

Astrophysics of Galaxies · Physics 2019-11-13 Helmer H. Koppelman , Amina Helmi , Davide Massari , Adrian M. Price-Whelan , Tjitske K. Starkenburg

We use N-body simulations of dark matter haloes in cold dark matter (CDM) and a large set of different warm dark matter (WDM) cosmologies to demonstrate that the spherically averaged density profile of dark matter haloes has a shape that…

Astrophysics of Galaxies · Physics 2015-05-20 E. Polisensky , M. Ricotti

Thanks to the ever increasing computational power and the development of more sophisticated algorithms, numerical N-body simulations are now uncovering several phenomenological relations between the physical properties of dark matter haloes…

Astrophysics · Physics 2009-11-13 Yago Ascasibar , Stefan Gottloeber