Searching for Dark Matter Annihilation in the Smith High-Velocity Cloud

Abstract

Recent observations suggest that some high-velocity clouds may be confined by massive dark matter halos. In particular, the proximity and proposed dark matter content of the Smith Cloud make it a tempting target for the indirect detection of dark matter annihilation. We argue that the Smith Cloud may be a better target than some Milky Way dwarf spheroidal satellite galaxies and use gamma-ray observations from the Fermi Large Area Telescope to search for a dark matter annihilation signal. No significant gamma-ray excess is found coincident with the Smith Cloud, and we set strong limits on the dark matter annihilation cross section assuming a spatially-extended dark matter profile consistent with dynamical modeling of the Smith Cloud. Notably, these limits exclude the canonical thermal relic cross section ($\sim 3\times 10^{-26}{\mathrm{cm}}^3{\mathrm{s}}^{-1}$) for dark matter masses $\lesssim 30$ GeV annihilating via the $b\bar{b}$ or ${\tau }^{+}{\tau }^{-}$ channels for certain assumptions of the dark matter density profile; however, uncertainties in the dark matter content of the Smith Cloud may significantly weaken these constraints.

arXiv comment7 pages, 5 figures. Published in ApJ

References in corpus (36)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• The Structure of Cold Dark Matter Halos
• Particle Dark Matter: Evidence, Candidates and Constraints
• The Large Area Telescope on the Fermi Gamma-ray Space Telescope Mission
• The Leiden/Argentine/Bonn (LAB) Survey of Galactic HI: Final data release of the combined LDS and IAR surveys with improved stray-radiation corrections
• The Milky Way in Molecular Clouds: A New Complete CO Survey
• The Aquarius Project: the subhalos of galactic halos
• The Structure of Dark Matter Haloes in Dwarf Galaxies
• Fermi Large Area Telescope Second Source Catalog
• Propagation of cosmic-ray nucleons in the Galaxy
• Dark Matter Annihilation in The Galactic Center As Seen by the Fermi Gamma Ray Space Telescope
• Fermi-LAT Observations of the Diffuse Gamma-Ray Emission: Implications for Cosmic Rays and the Interstellar Medium
• The tumultuous lives of galactic dwarfs and the missing satellites problem
• Constraining Dark Matter Models from a Combined Analysis of Milky Way Satellites with the Fermi Large Area Telescope
• On The Origin Of The Gamma Rays From The Galactic Center
• Detection of a Gamma-Ray Source in the Galactic Center Consistent with Extended Emission from Dark Matter Annihilation and Concentrated Astrophysical Emission
• Dark Matter Constraints from Observations of 25 Milky Way Satellite Galaxies with the Fermi Large Area Telescope
• Dark Matter and Pulsar Model Constraints from Galactic Center Fermi-LAT Gamma Ray Observations
• High Velocity Clouds: Building Blocks of the Local Group
• Constraints on cosmic-ray propagation models from a global Bayesian analysis
• Exclusion of canonical WIMPs by the joint analysis of Milky Way dwarfs with Fermi
• Observations of Milky Way Dwarf Spheroidal galaxies with the Fermi-LAT detector and constraints on Dark Matter models
• Constraints on Dark Matter Annihilation in Clusters of Galaxies with the Fermi Large Area Telescope
• Pre-launch estimates for GLAST sensitivity to Dark Matter annihilation signals
• Fitting the Gamma-Ray Spectrum from Dark Matter with DMFIT: GLAST and the Galactic Center Region
• Dark matter searches with Cherenkov telescopes: nearby dwarf galaxies or local galaxy clusters?
• Smith's Cloud: A High-velocity Cloud Colliding with the Milky Way
• Constraining Extended Gamma-ray Emission from Galaxy Clusters
• Fermi-LAT constraints on dark matter annihilation cross section from observations of the Fornax cluster
• Evidence for extended gamma-ray emission from galaxy clusters
• Constraints on WIMP Annihilation for Contracted Dark Matter in the Inner Galaxy with the Fermi-LAT
• The GALFA-HI Compact Cloud Catalog
• Ionized Gas in the Smith Cloud
• Relics of structure formation: extra-planar gas and high-velocity clouds around the Andromeda Galaxy
• The Smith Cloud: high-velocity accretion and dark-matter confinement
• Do High-Velocity Clouds trace the Dark Matter subhalo population?

Cited by in corpus (16)

• Sensitivity Projections for Dark Matter Searches with the Fermi Large Area Telescope
• Search for Gamma-ray Emission from Dark Matter Annihilation in the Large Magellanic Cloud with the Fermi Large Area Telescope
• WIMP searches with gamma rays in the Fermi era: challenges, methods and results
• Fermi-LAT Observations of High- and Intermediate-Velocity Clouds: Tracing Cosmic Rays in the Halo of the Milky Way
• Model-independent analysis of the DAMPE excess
• The Mopra Southern Galactic Plane CO Survey - Data Release 3
• Search for Gamma-ray Emission from Dark Matter Annihilation in the Small Magellanic Cloud with the Fermi Large Area Telescope
• Search for $\gamma$-ray emission from dark matter particle interactions from Andromeda and Triangulum Galaxies with the Fermi Large Area Telescope
• Strong Optimized Conservative Fermi-LAT Constraints on Dark Matter Models from the Inclusive Photon Spectrum
• Simplified Dark Matter Models Confront the Gamma Ray Excess
• Selection Rule for Enhanced Dark Matter Annihilation
• TeV Dark Matter Searches in the Extragalactic Gamma-Ray Sky
• Wavelet-Based Techniques for the Gamma-Ray Sky
• Search for gamma-ray line features from Milky Way satellites with Fermi-LAT Pass 8 data
• Synchrotron Emission from Dark Matter in Galactic Subhalos. A Look into the Smith Cloud
• Dark matter properties implied by gamma ray interstellar emission models