The viability of low-mass subhaloes as targets for gamma-ray dark matter searches
arXiv:2309.02330 · doi:10.1093/mnras/stae940
Abstract
In this work, we investigate the discovery potential of low-mass Galactic dark matter (DM) subhaloes for indirect searches of DM. We use data from the Via Lactea II (VL-II) N-body cosmological simulation, which resolves subhaloes down to solar masses and it is thus ideal for this purpose. First, we characterize the abundance, distribution and structural properties of the VL-II subhalo population in terms of both subhalo masses and maximum circular velocities. Then, we repopulate the original simulation with millions of subhaloes of masses down to about five orders of magnitude below the minimum VL-II subhalo mass (more than one order of magnitude in velocities). We compute subhalo DM annihilation astrophysical "J-factors" and angular sizes for the entire subhalo population, by placing the Earth at a random position but at the right galactocentric distance in the simulation. Thousands of these realizations are generated in order to obtain statistically meaningful results. We find that some nearby low-mass Galactic subhaloes, not massive enough to retain stars or gas, may indeed yield DM annihilation fluxes comparable to those expected from other, more massive and acknowledgeable DM targets like dwarf satellite galaxies. Typical angular sizes are of the order of the degree, thus subhaloes potentially appearing as extended sources in gamma-ray telescopes, depending on instrument angular resolution and sensitivity. Our work shows that low-mass Galactic subhaloes with no visible counterparts are expected to play a relevant role in current and future indirect DM search searches and should indeed be considered as excellent DM targets.
16 pages, 16 figures. Accepted in MNRAS; matches published version
References in corpus (35)
- The NumPy array: a structure for efficient numerical computation
- Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology
- Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
- Introducing the Illustris Project: Simulating the coevolution of dark and visible matter in the Universe
- The Auriga Project: the properties and formation mechanisms of disc galaxies across cosmic time
- Searching for Dark Matter Annihilation in Recently Discovered Milky Way Satellites with Fermi-LAT
- Dark matter and cosmic structure
- Assembly bias in the clustering of dark matter haloes
- Disruption of Dark Matter Substructure: Fact or Fiction?
- Dark Matter Substructure in Numerical Simulations: A Tale of Discreteness Noise, Runaway Instabilities, and Artificial Disruption
- The Uchuu Simulations: Data Release 1 and Dark Matter Halo Concentrations
- Dark Matter: A Primer
- The Population of Dark Matter Subhaloes: Mass Functions and Average Mass Loss Rates
- Large-scale dark matter simulations
- The moment of truth for WIMP Dark Matter
- Determining the full satellite population of a Milky Way-mass halo in a highly resolved cosmological hydrodynamic simulation
- Analytical Approach to Subhaloes Population in Dark Matter Haloes
- The tidal evolution of dark matter substructure -- I. Subhalo density profiles
- Symphony: Cosmological Zoom-in Simulation Suites over Four Decades of Host Halo Mass
- DASH: a library of dynamical subhalo evolution
- LCDM halo substructure properties revealed with high resolution and large volume cosmological simulations
- Unidentified Gamma-ray Sources as Targets for Indirect Dark Matter Detection with the Fermi-Large Area Telescope
- Tidal Stripping in the Adiabatic Limit
- Spectral and spatial analysis of the dark matter subhalo candidates among Fermi Large Area Telescope unidentified sources
- SatGen -- II. Assessing the impact of a disc potential on subhalo populations
- The cosmological dependence of halo and galaxy assembly bias
- The Effects of Varying Cosmological Parameters on Halo Substructure
- Baryonic effects on the detectability of annihilation radiation from dark matter subhaloes around the Milky Way
- Diffuse gamma-ray constraints on dark matter revisited. I: the impact of subhalos
- Shedding light on low-mass subhalo survival and annihilation luminosity with numerical simulations
- Investigating the detection of dark matter subhalos as extended sources with Fermi-LAT
- Sensitivity of the Cherenkov Telescope Array to dark subhalos
- Cherenkov Telescope Array sensitivity to branon dark matter models
- Spatial extension of dark subhalos as seen by Fermi-LAT and implications for WIMP constraints
- An Accurate Comprehensive Approach to Substructure: III. Masses and Formation Times of the Host Haloes