The AIDA-TNG project: 3D halo shapes

Abstract

Context. The shapes of dark matter halos can be used to constrain the fundamental properties of dark matter. In standard Cold Dark Matter (CDM) cosmologies, halos are typically triaxial, with a preference for prolate configurations, particularly at low masses and high redshift. Aims. We focus on the characterization of total matter 3D shape in alternative dark matter models, such as Self-Interacting Dark Matter (SIDM) and Warm Dark Matter (WDM). These scenarios predict different structural properties due to collisional effects or the suppression of small-scale power. Methods. We measure the different halo component shapes - dark matter, stars and gas - at various radii from the center in the AIDA-TNG (Alternative Interacting Dark Matter and Astrophysics - TNG), which is a suite of high-resolution cosmological simulations built upon the IllustrisTNG framework. The intent is to systematically study how different dark matter models - specifically, SIDM and WDM - affect galaxy formation and the structure of dark matter halos, when realistic baryonic physics is also included. Results. SIDM models tend to produce rounder and more isotropic halos, especially in the inner regions, as a result of momentum exchange between dark matter particles. WDM halos are also slightly more spherical than their CDM counterparts, and are typically less concentrated. In all cases, the inclusion of self-consistent baryonic physics makes the central regions of all halos rounder, while still revealing clear distinctions among the various dark matter models. Conclusions. The general framework presented in this work, based on the 3D halo shape, can be useful to interpret multi-wavelength data analyses of galaxies and clusters.

12 pages and 8 figures, accepted for publication in A&A on 08/01/2026 (Article reference: aa58400-25). Find more information on AIDA-TNG here: https://gdespali.github.io/AIDA

References in corpus (108)

• A Universal Density Profile from Hierarchical Clustering
• The Structure of Cold Dark Matter Halos
• The cosmological simulation code GADGET-2
• Simulating the joint evolution of quasars, galaxies and their large-scale distribution
• Efficient Computation of CMB anisotropies in closed FRW models
• Large scale bias and the peak background split
• Populating a cluster of galaxies - I. Results at z=0
• Introducing the Illustris Project: Simulating the coevolution of dark and visible matter in the Universe
• Observational evidence for self-interacting cold dark matter
• Simulating Galaxy Formation with the IllustrisTNG Model
• Ellipsoidal collapse and an improved model for the number and spatial distribution of dark matter haloes
• First results from the IllustrisTNG simulations: the stellar mass content of groups and clusters of galaxies
• Small-Scale Challenges to the $\Lambda$CDM Paradigm
• Properties of galaxies reproduced by a hydrodynamic simulation
• Simulating galaxy formation with black hole driven thermal and kinetic feedback
• Dark Matter Self-interactions and Small Scale Structure
• Substructures in hydrodynamical cluster simulations
• KiDS-450: Cosmological parameter constraints from tomographic weak gravitational lensing
• An excursion set model of hierarchical clustering: Ellipsoidal collapse and the moving barrier
• Response of dark matter halos to condensation of baryons: cosmological simulations and improved adiabatic contraction model
• Constraining Warm Dark Matter candidates including sterile neutrinos and light gravitinos with WMAP and the Lyman-alpha forest
• Triaxial Modeling of Halo Density Profiles with High-resolution N-body Simulations
• Warm Dark Matter as a solution to the small scale crisis: new constraints from high redshift Lyman-alpha forest data
• Cosmological Simulations with Self-Interacting Dark Matter I: Constant Density Cores and Substructure
• KiDS-1000 Cosmology: Multi-probe weak gravitational lensing and spectroscopic galaxy clustering constraints
• The Shape of Dark Matter Halos: Dependence on Mass, Redshift, Radius, and Formation
• Subhaloes in Self-Interacting Galactic Dark Matter Haloes
• Dark Matter Halos as Particle Colliders: A Unified Solution to Small-Scale Structure Puzzles from Dwarfs to Clusters
• Euclid. I. Overview of the Euclid mission
• A primer on hierarchical galaxy formation: the semi-analytical approach
• Cosmological Simulations with Self-Interacting Dark Matter II: Halo Shapes vs. Observations
• COLOSSUS: A python toolkit for cosmology, large-scale structure, and dark matter halos
• Scaling relations for galaxy clusters in the Millennium-XXL simulation
• Cold dark matter: controversies on small scales
• The spin and shape of dark matter haloes in the Millennium simulation of a LambdaCDM universe
• The stellar mass assembly of galaxies in the Illustris simulation: growth by mergers and the spatial distribution of accreted stars
• Overview of the Instrumentation for the Dark Energy Spectroscopic Instrument
• Constraining Self-Interacting Dark Matter with the Milky Way's dwarf spheroidals
• The haloes of bright satellite galaxies in a warm dark matter universe
• Halo Properties in Cosmological Simulations of Self-Interacting Cold Dark Matter
• Baryon effects on the internal structure of LCDM halos in the EAGLE simulations
• The Mass-Concentration-Redshift Relation of Cold and Warm Dark Matter Halos
• The Effect of Gas Cooling on the Shapes of Dark Matter Halos
• Hierarchical galaxy formation and substructure in the Galaxy's stellar halo
• Core Formation in Dwarf Halos with Self Interacting Dark Matter: No Fine-Tuning Necessary
• The Structure and Dynamical Evolution of Dark Matter Halos
• The Density Profiles of Massive, Relaxed Galaxy Clusters. II. Separating Luminous and Dark Matter in Cluster Cores
• The universality of the virial halo mass function and models for non-universality of other halo definitions
• ETHOS - An Effective Theory of Structure Formation: Dark matter physics as a possible explanation of the small-scale CDM problems
• Measuring the Three-Dimensional Structure of Galaxy Clusters. I. Application to a Sample of 25 Clusters
• The role of mergers and halo spin in shaping galaxy morphology
• The Population of Dark Matter Subhaloes: Mass Functions and Average Mass Loss Rates
• An excess of small-scale gravitational lenses observed in galaxy clusters
• The Shape of Dark Matter Haloes in the Aquarius Simulations: Evolution and Memory
• Anisotropic Distribution of SDSS Satellite Galaxies: Planar (not Polar) Alignment
• The velocity shear tensor: tracer of halo alignment
• The impact of baryons on the spins and shapes of dark matter haloes
• Anisotropy in the Distribution of Satellite Galaxy Orbits
• On determining the shape of matter distributions
• Constraining Velocity-dependent Self-Interacting Dark Matter with the Milky Way's dwarf spheroidal galaxies
• Shape of Dark Matter Haloes in the Illustris Simulation: Effects of Baryons
• Galaxy Shapes and Intrinsic Alignments in The MassiveBlack-II Simulation
• Giant cluster arcs as a constraint on the scattering cross-section of dark matter
• The impact of baryonic physics on the subhalo mass function and implications for gravitational lensing
• Observable tests of self-interacting dark matter in galaxy clusters: BCG wobbles in a constant density core
• Cosmic web alignments with the shape, angular momentum and peculiar velocities of dark matter haloes
• The alignment of satellite galaxies and cosmic filaments: observations and simulations
• Some like it triaxial: the universality of dark matter halo shapes and their evolution along the cosmic time
• The diverse density profiles of galaxy clusters with self-interacting dark matter plus baryons
• The Assembly of Matter in Galaxy Clusters
• Evaporating the Milky Way halo and its satellites with inelastic self-interacting dark matter
• Intrinsic alignments of galaxies in the EAGLE and cosmo-OWLS simulations
• Arc sensitivity to cluster ellipticity, asymmetries and substructures
• NIHAO project II: Halo shape, phase-space density and velocity distribution of dark matter in galaxy formation simulations
• The Morphologies and Alignments of Gas, Mass, and the Central Galaxies of CLASH Clusters of Galaxies
• Galaxy Formation in WDM Cosmology
• Hot and Cooled baryons in SPH simulations of galaxy clusters: physics and numerics
• Universality of dark matter haloes shape over six decades in mass: Insights from the Millennium XXL and SBARBINE simulations
• Galaxy-halo alignments in the Horizon-AGN cosmological hydrodynamical simulation
• The surprising accuracy of isothermal Jeans modelling of self-interacting dark matter density profiles
• Cosmic vorticity and the origin of halo spins
• The impact of baryon physics on the structure of high-redshift galaxies
• Galaxy shapes and alignments in the MassiveBlack-II hydrodynamic and dark matter-only simulations
• Radial velocity moments of dark matter haloes
• The dynamical structure of dark matter haloes
• Ellipsoidal halo finders and implications for models of triaxial halo formation
• Mass, shape and thermal properties of A1689 by a multi-wavelength X-ray, lensing and Sunyaev-Zel'dovich analysis
• A look to the inside of haloes: a characterisation of the halo shape as a function of overdensity in the Planck cosmology
• Lensing Measurements of the Ellipticity of LRG Dark Matter Halos
• nIFTy Galaxy Cluster simulations IV: Quantifying the Influence of Baryons on Halo Properties
• Impact of baryons on the cluster mass function and cosmological parameter determination
• The effects of ellipticity and substructure on estimates of cluster density profiles based on lensing and kinematics
• The mass dependence of dark matter halo alignments with large-scale structure
• The offsets between galaxies and their dark matter in Lambda-CDM
• Constraining SIDM with halo shapes: revisited predictions from realistic simulations of early-type galaxies
• The impact of galactic feedback on the shapes of dark-matter haloes
• Euclid preparation. XXXII. Evaluating the weak lensing cluster mass biases using the Three Hundred Project hydrodynamical simulations
• Endothermic self-interacting dark matter in Milky Way-like dark matter haloes
• Reconciling galaxy cluster shapes, measured by theorists vs observers
• Introducing the AIDA-TNG project: galaxy formation in alternative dark matter models
• The impact of Self-Interacting Dark Matter on the Intrinsic Alignments of Galaxies
• Properties and observables of massive galaxies in self-interacting dark matter cosmologies
• Why weak lensing cluster shapes are insensitive to self-interacting dark matter
• Toward a Physical Understanding of Galaxy-Halo Alignment
• Mass Dependence of Galaxy-Halo Alignment in LOWZ and CMASS
• Accretion of satellites onto central galaxies in clusters: merger mass ratios and orbital parameters
• Getting in shape with minimal energy. A variational principle for protohaloes
• The XXL Survey: XLVIII; X-ray follow-up of distant XXL clusters: Masses, scaling relations and AGN contamination