Predicting the dark matter velocity distribution in galactic structures: tests against hydrodynamic cosmological simulations

Autor: Martin Stref, Julien Lavalle, Thomas Lacroix, Emmanuel Nezri, A. Nuñez-Castiñeyra
Přispěvatelé: Laboratoire Univers et Particules de Montpellier (LUPM), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Annecy-le-Vieux de Physique Théorique (LAPTH), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), ANR-18-CE31-0006,GaDaMa,Matière Noire Galactique(2018)
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Cosmology and Nongalactic Astrophysics (astro-ph.CO)
Structure formation
Dark matter
galaxy: dark matter
FOS: Physical sciences
Primordial black hole
dark matter: phase space
Astrophysics
Astrophysics::Cosmology and Extragalactic Astrophysics
anisotropy
Parameter space
Gravitational microlensing
01 natural sciences
Galactic dynamics
High Energy Physics - Phenomenology (hep-ph)
0103 physical sciences
structure formation
galaxy: mass
numerical calculations
Astrophysics::Galaxy Astrophysics
Physics
010308 nuclear & particles physics
Astronomy and Astrophysics
Observable
dark matter searches
Astrophysics - Astrophysics of Galaxies
Galaxy
formation: structure
Stars
High Energy Physics - Phenomenology
annihilation
Astrophysics of Galaxies (astro-ph.GA)
[PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph]
hydrodynamics
dark matter: velocity
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
black hole: primordial
Astrophysics - Cosmology and Nongalactic Astrophysics
Zdroj: JCAP
JCAP, 2020, 10, pp.031. ⟨10.1088/1475-7516/2020/10/031⟩
DOI: 10.1088/1475-7516/2020/10/031⟩
Popis: Reducing theoretical uncertainties in Galactic dark matter (DM) searches is an important challenge as several experiments are now delving into the parameter space relevant to popular (particle or not) candidates. Since many DM signal predictions rely on the knowledge of the DM velocity distribution---direct searches, capture by stars, p-wave-suppressed or Sommerfeld-enhanced annihilation rate, microlensing of primordial black holes, etc.---it is necessary to assess the accuracy of our current theoretical handle. Beyond Maxwellian approximations or ad-hoc extrapolations of fits on cosmological simulations, approaches have been proposed to self-consistently derive the DM phase-space distribution only from the detailed mass content of the Galaxy and some symmetry assumptions (e.g. the Eddington inversion and its anisotropic extensions). Although theoretically sound, these methods are still based on simplifying assumptions and their relevance to real galaxies can be questioned. In this paper, we use zoomed-in cosmological simulations to quantify the associated uncertainties. Assuming isotropy, we predict the speed distribution and its moments from the DM and baryonic content measured in simulations, and compare them with the true ones. Taking as input galactic mass models fitted on full simulation data, we reach a predictivity down to ~ 10% for some velocity-related observables, significantly better than some Maxwellian models. This moderate theoretical error is particularly encouraging at a time when stellar surveys like the Gaia mission should allow us to improve constraints on Galactic mass models.
60 pages, 31 figures, matches the version published in JCAP
Databáze: OpenAIRE
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