Towards a more rigorous treatment of uncertainties on the velocity distribution of dark matter particles for capture in stars

Abstract

Dark matter (DM) capture in stars offers a rich phenomenology that makes it possible to probe a wide variety of particle DM scenarios in diverse astrophysical environments. In spite of decades of improvements to refine predictions of capture-related observables and better quantify astrophysical and particle-physics uncertainties, the actual impact of the Galactic phase-space distribution function of DM has been overlooked. In this work, we tackle this problem by making use of self-consistent equilibrium phase-space models based on the Eddington inversion formalism and an extension of this method to a DM halo with some degree of anisotropy in velocity space. We demonstrate that incorrectly accounting for the variation of the DM velocity distribution with position in the Galaxy leads to a systematic error between a factor two and two orders of magnitude, depending in particular on the target star, the DM candidate mass and the type of interaction involved. Moreover, we show that underlying phase-space properties, such as the anisotropy of the velocity tensor, actually play an important part -- previously disregarded -- and can have a sizable impact on predictions of capture rates and subsequent observables. We argue that Eddington-like methods, which self-consistently account for kinematic constraints on the components of the Galaxy, actually provide a reliable next-to-minimal approach to narrow down uncertainties from phase-space modeling on predictions of observables related to DM capture in stars.

44 pages, 7 figures, matches version published in JCAP

References in corpus (31)

• The Gaia mission
• Modules for Experiments in Stellar Astrophysics (MESA)
• The mass distribution and gravitational potential of the Milky Way
• Asymmetric Dark Matter
• Dynamical modelling of the Galactic bulge and bar: the Milky Way's bar pattern speed, stellar, and dark matter mass distribution
• WIMP Annihilation and Cooling of Neutron Stars
• Compact Stars as Dark Matter Probes
• Dark matter and the first stars: a new phase of stellar evolution
• Phase-space structure in the local dark matter distribution and its signature in direct detection experiments
• The old nuclear star cluster in the Milky Way: dynamics, mass, statistical parallax, and black hole mass
• Large scale kinematics and dynamical modelling of the Milky Way nuclear star cluster
• Constraints on Bosonic Dark Matter From Observations of Old Neutron Stars
• Detecting Dark Matter with Imploding Pulsars in the Galactic Center
• Halo-to-Halo Similarity and Scatter in the Velocity Distribution of Dark Matter
• Disassembling the Galaxy with angle-action coordinates
• Action-based distribution functions for spheroidal galaxy components
• Dark Kinetic Heating of Neutron Stars from Contact Interactions with Relativistic Targets
• The distribution function of dark matter in massive haloes
• Dark matter burners
• Dark matter in the solar system II: WIMP annihilation rates in the Sun
• A possible indication of momentum-dependent asymmetric dark matter in the Sun
• The Zero Age Main Sequence of WIMP burners
• A centrally heated dark halo for our Galaxy
• First asteroseismic limits on the nature of dark matter
• Taming astrophysical bias in direct dark matter searches
• Made-to-Measure Dark Matter Haloes, Elliptical Galaxies and Dwarf Galaxies in Action Coordinates
• Signatures of dark matter burning in nuclear star clusters
• Predicting the dark matter velocity distribution in galactic structures: tests against hydrodynamic cosmological simulations
• Making sense of the local Galactic escape speed estimates in direct dark matter searches
• Antimatter cosmic rays from dark matter annihilation: First results from an N-body experiment
• Two-integral distribution functions in axisymmetric galaxies: implications for dark matter searches

Cited by in corpus (10)

• Impact of galactic distributions in celestial capture of dark matter
• Dark matter capture and annihilation in stars: Impact on the red giant branch tip
• Improved bounds on the bosonic dark matter with pulsars in the Milky Way
• Halo-independent bounds on the non-relativistic effective theory of WIMP-nucleon scattering from direct detection and neutrino observations
• Halo-independent bounds on Inelastic Dark Matter
• Analytical insight into dark matter subhalo boost factors for Sommerfeld-enhanced $s$- and $p$-wave $\gamma$-ray signals
• Testing the predictions of axisymmetric distribution functions of galactic dark matter with hydrodynamical simulations
• Sensitivity of WIMP bounds on the velocity distribution in the limit of a massless mediator
• Dark Matter in Stars
• Heavy dark matter in rapidly evolving massive stars