Indication of Gamma-ray Emission from the Newly Discovered Dwarf Galaxy Reticulum II

Abstract

We present a search for gamma-ray emission from the direction of the newly discovered dwarf galaxy Reticulum II. Using Fermi-LAT data, we detect a signal that exceeds expected backgrounds between ~2-10 GeV and is consistent with annihilation of dark matter for particle masses less than a few x 10^2 GeV. Modeling the background as a Poisson process based on Fermi-LAT diffuse models, and taking into account trials factors, we detect emission with p-value less than 9.8 x 10^-5 (>3.7 sigma). An alternative, model-independent treatment of background reduces the significance, raising the p-value to 9.7 x 10^-3 (2.3 sigma). Even in this case, however, Reticulum II has the most significant gamma-ray signal of any known dwarf galaxy. If Reticulum II has a dark matter halo that is similar to those inferred for other nearby dwarfs, the signal is consistent with the s-wave relic abundance cross section for annihilation.

6 pages, 4 figures; matches version to appear in Physical Review Letters

References in corpus (26)

• Beasts of the Southern Wild: Discovery of nine Ultra Faint satellites in the vicinity of the Magellanic Clouds
• Background model systematics for the Fermi GeV excess
• CRATES: An All-Sky Survey of Flat-Spectrum Radio Sources
• Roma-BZCAT: A multifrequency catalogue of Blazars
• Weak Corrections are Relevant for Dark Matter Indirect Detection
• Dwarf galaxy annihilation and decay emission profiles for dark matter experiments
• Precise constraints on the dark matter content of Milky Way dwarf galaxies for gamma-ray experiments
• GeV excess in the Milky Way: The Role of Diffuse Galactic gamma ray Emission template
• The Most Dark Matter Dominated Galaxies: Predicted Gamma-ray Signals from the Faintest Milky Way Dwarfs
• A Comprehensive Search for Dark Matter Annihilation in Dwarf Galaxies
• Detecting dark matter WIMPs in the Draco dwarf: a multi-wavelength perspective
• Millisecond pulsars and the Galactic Center gamma-ray excess: the importance of luminosity function and secondary emission
• H.E.S.S. constraints on Dark Matter annihilations towards the Sculptor and Carina Dwarf Galaxies
• Millisecond pulsar interpretation of the Galactic center gamma-ray excess
• Indirect Dark Matter Detection Limits from the Ultra-Faint Milky Way Satellite Segue 1
• Extracting limits on Dark Matter annihilation from gamma-ray observations towards dwarf spheroidal galaxies
• Dark matter line search using a joint analysis of dwarf galaxies with the Fermi Gamma-ray Space Telescope
• The Gamma-Ray-Flux Probability Distribution Function from Galactic Halo Substructure
• A model-independent analysis of the Fermi Large Area Telescope gamma-ray data from the Milky Way dwarf galaxies and halo to constrain dark matter scenarios
• Distinguishing Dark Matter from Unresolved Point Sources in the Inner Galaxy with Photon Statistics
• A Search for Dark Matter Annihilation with the Whipple 10m Telescope
• Discovery of a New Galactic Center Excess Consistent with Upscattered Starlight
• Dark Matter and the CACTUS Gamma-Ray Excess from Draco
• Constraining Dark Matter in Galactic Substructure
• A stacked analysis of 115 pulsars observed by the Fermi LAT
• Improving the Sensitivity of Gamma-Ray Telescopes to Dark Matter Annihilation in Dwarf Spheroidal Galaxies

Cited by in corpus (119)

• The Dark Energy Survey: more than dark energy - an overview
• WIMP dark matter candidates and searches - current status and future prospects
• Eight Ultra-faint Galaxy Candidates Discovered in Year Two of the Dark Energy Survey
• Searching for Dark Matter Annihilation in Recently Discovered Milky Way Satellites with Fermi-LAT
• The DArk Matter Particle Explorer mission
• Dark matter cores all the way down
• Possible dark matter annihilation signal in the AMS-02 antiproton data
• MadDM v.3.0: a Comprehensive Tool for Dark Matter Studies
• Gravitational probes of dark matter physics
• Model-Independent Indirect Detection Constraints on Hidden Sector Dark Matter
• Snake in the Clouds: A new nearby dwarf galaxy in the Magellanic bridge
• A Global Analysis of Dark Matter Signals from 27 Dwarf Spheroidal Galaxies using 11 Years of Fermi-LAT Observations
• A Deeper Look at the New Milky Way Satellites: Sagittarius II, Reticulum II, Phoenix II, and Tucana III
• Dark Matter Interpretation of the Fermi-LAT Observation Toward the Galactic Center
• New Limits on the Dark Matter Lifetime from Dwarf Spheroidal Galaxies using Fermi-LAT
• Dark Matter in Dwarf Spheroidal Galaxies and Indirect Detection: A Review
• The Globular Cluster - Dark Matter Halo Connection
• The Return of the Templates: Revisiting the Galactic Center Excess with Multi-Messenger Observations
• On The Gamma-Ray Emission From Reticulum II and Other Dwarf Galaxies
• Probing dark matter annihilation in the Galaxy with antiprotons and gamma rays
• The inert doublet model in the light of Fermi-LAT gamma-ray data: a global fit analysis
• Ships Passing in the Night: Spectroscopic Analysis of Two Ultra-Faint Satellites in the Constellation Carina
• Search for gamma-ray emission from eight dwarf spheroidal galaxy candidates discovered in Year Two of Dark Energy Survey with Fermi-LAT data
• Gamma-rays from Dark Showers with Twin Higgs Models
• Bright gamma-ray Galactic Center excess and dark dwarfs: Strong tension for dark matter annihilation despite Milky Way halo profile
• Environmental Quenching of Low-Mass Field Galaxies
• Dark matter in the Reticulum II dSph: a radio search
• Sommerfeld-Enhanced $J$-Factors For Dwarf Spheroidal Galaxies
• Search for 511 keV Emission in Satellite Galaxies of the Milky Way with INTEGRAL/SPI
• Revisit of cosmic ray antiprotons from dark matter annihilation with updated constraints on the background model from AMS-02 and collider data
• Nonstandard Yukawa Couplings and Higgs Portal Dark Matter
• The Positron Puzzle
• Contamination of stellar-kinematic samples and uncertainty about dark matter annihilation profiles in ultrafaint dwarf galaxies: the example of Segue I
• Search for Gamma-ray Emission from Dark Matter Annihilation in the Small Magellanic Cloud with the Fermi Large Area Telescope
• On the R-Process Enrichment of Dwarf Spheroidal Galaxies
• Testing Bose-Einstein Condensate dark matter models with the SPARC galactic rotation curves data
• The Semi-Hooperon: Gamma-ray and anti-proton excesses in the Galactic Center
• Search for $\gamma$-ray emission from dark matter particle interactions from Andromeda and Triangulum Galaxies with the Fermi Large Area Telescope
• LikeDM: likelihood calculator of dark matter detection
• Search for right-handed neutrinos from dark matter annihilation with gamma-rays
• Is The Gamma-Ray Source 3FGL J2212.5+0703 A Dark Matter Subhalo?
• Indirect Dark Matter Detection for Flattened Dwarf Galaxies
• Indirect Detection Constraints on s and t Channel Simplified Models of Dark Matter
• Global fit of pseudo-Nambu-Goldstone Dark Matter
• Impact of axisymmetric mass models for dwarf spheroidal galaxies on indirect dark matter searches
• Extending Fermi-LAT and H.E.S.S. Limits on Gamma-ray Lines from Dark Matter Annihilation
• A Multi-frequency analysis of dark matter annihilation interpretations of recent anti-particle and gamma-ray excesses in cosmic structures
• Reticulum II: Particle Dark Matter and Primordial Black Holes Limits
• p-wave Annihilating Dark Matter from a Decaying Predecessor and the Galactic Center Excess
• Point Sources from Dissipative Dark Matter
• The Spatial Morphology of the Secondary Emission in the Galactic Center Gamma-Ray Excess
• Secluded WIMPs, QED with massive photons, and the galactic center gamma-ray excess
• Prospects for annihilating Dark Matter towards Milky Way's dwarf galaxies by the Cherenkov Telescope Array
• Dark Matter Density Profiles in Dwarf Galaxies: Linking Jeans Modeling Systematics and Observation
• Impact of cosmological and astrophysical constraints on dark matter simplified models
• MSSM A-funnel and the Galactic Center Excess: Prospects for the LHC and Direct Detection Experiments
• Condensate flow in holographic models in the presence of dark matter
• Pseudoscalar Portal Dark Matter and New Signatures of Vector-like Fermions
• A method for comparing non-nested models with application to astrophysical searches for new physics
• Gamma-Ray Excess and the Minimal Dark Matter Model
• Dark Higgs Channel for FERMI GeV $\gamma$-ray Excess
• Updated Collider and Direct Detection Constraints on Dark Matter Models for the Galactic Center Gamma-Ray Excess
• Lepton-Flavor Violating Mediators
• Formation of globular clusters with internal abundance spreads in r-process elements: strong evidence for prolonged star formation
• TeV Dark Matter Searches in the Extragalactic Gamma-Ray Sky
• Dark matter annihilation into right-handed neutrinos and the galactic center gamma-ray excess
• The contribution of dissolving star clusters to the population of ultra-faint objects in the outer halo of the Milky Way
• Ultra-compact spherically symmetric dark matter charged star objects
• On self-gravitating strange dark matter halos around galaxies
• The Gamma-ray Afterglows of Tidal Disruption Events
• Search for gamma-ray line features from Milky Way satellites with Fermi-LAT Pass 8 data
• MADHAT: Model-Agnostic Dark Halo Analysis Tool
• 3FGL J1924.8-1034 : A Spatially-Extended Stable Unidentified GeV Source?
• Holographic vortices in the presence of dark matter sector
• Testing the dark matter subhalo hypothesis of the gamma-ray source 3FGL J2212.5+0703
• Search for gamma-ray emission from the 12 nearby dwarf spheroidal galaxies with 12 years of Fermi-LAT data
• What the Milky Way's Dwarfs tell us about the Galactic Center extended excess
• Comparing Galactic Center MSSM dark matter solutions to the Reticulum II gamma-ray data
• A Robust Method for Treating Astrophysical Mismodeling in Dark Matter Annihilation Searches of Dwarf Spheroidal Galaxies
• Search for gamma-ray emission from the nearby dwarf spheroidal galaxies with 9 years of Fermi-LAT data
• The case for 100 GeV bino dark matter: A dedicated LHC tri-lepton search
• Dwarf spheroidal $J$-factor likelihoods for generalized NFW profiles
• Ultra faint dwarf galaxies: an arena for testing dark matter versus modified gravity
• A Gaia DR2 search for dwarf galaxies towards Fermi-LAT sources: implications for annihilating dark matter
• Searching for Gamma-Ray Emission from Reticulum II by Fermi-LAT
• Multimessenger TeV Dark Matter: a mini review
• Influence of dark matter on black hole scalar hair
• Analysis of Fermi-LAT data from Tucana-II: Possible constraints on the Dark Matter models with an intriguing hint of a signal
• Dependence of accessible dark matter annihilation cross-sections on the density profiles of dwarf spheroidal galaxies with the Cherenkov Telescope Array
• Study of WIMP annihilations into a pair of on-shell scalar mediators
• Viscosity bound for anisotropic superfluids with dark matter sector
• Consistency test of the AMS-02 antiproton excess with direct detection data based on the effective field theory approach
• Using $\gamma$-ray observations of dwarf spheroidal galaxies to test the possible common origin of the W-boson mass anomaly and the GeV $\gamma$-ray/antiproton excesses
• Explaining the Fermi Galactic Centre Excess in the CMSSM
• Viscosity of holographic fluid in the presence of dark matter sector
• Dark photon - dark energy stationary axisymmetric black holes
• Interpretations of the possible 42.7 GeV $\gamma$-ray line
• Dwarf Galaxy $\gamma$-excess and 3.55 keV X-ray Line In A Nonthermal Dark Matter Model
• Uniqueness of dark matter magnetized static black hole spacetime
• Self-interacting dark matter constraints in a thick dark disk scenario
• Asymmetric dark matter and effective number of neutrinos
• Dark matter constraints from an observation of dSphs and the LMC with the Baikal NT200
• A continuous multiple hypothesis testing framework for optimal exoplanet detection
• Dark matter influence on black hole objects thermodynamics
• Influence of dark photon on magnetized and charged particle orbits around static spherically symmetric black hole
• Charge transport in chiral solids as a possible tool in search of dark matter signals
• Dark matter, extra-terrestrial gamma-rays and the MSSM: a viability study
• Holographic superconductivity in the presence of dark matter: basic issues
• Extragalactic Background Light: Measurements and Applications
• Mass formulae and staticity condition for dark matter charged black holes
• Limits on Dark Matter Annihilation from the Shape of Radio Emission in M31
• Can synchrotron radiation reveal the presence of {\it dark sector} around black hole?
• Shocking Signals of Dark Matter Annihilation
• Radio-Frequency Searches for Dark Matter in Dwarf Galaxies
• Conformal anomaly transport induced by dark photon
• Black hole dark monopole system
• WIMP Dark Matter Searches in Reticulum II Using MeerKAT
• What Can Gamma-rays from Space tell us About the Madala Hypothesis?
• The interplay between cosmology, particle physics and astrophysics