Distinguishing Dark Matter from Unresolved Point Sources in the Inner Galaxy with Photon Statistics
arXiv:1412.6099 · doi:10.1088/1475-7516/2015/05/056
Abstract
Data from the Fermi Large Area Telescope suggests that there is an extended excess of GeV gamma-ray photons in the Inner Galaxy. Identifying potential astrophysical sources that contribute to this excess is an important step in verifying whether the signal originates from annihilating dark matter. In this paper, we focus on the potential contribution of unresolved point sources, such as millisecond pulsars (MSPs). We propose that the statistics of the photons---in particular, the flux probability density function (PDF) of the photon counts below the point-source detection threshold---can potentially distinguish between the dark-matter and point-source interpretations. We calculate the flux PDF via the method of generating functions for these two models of the excess. Working in the framework of Bayesian model comparison, we then demonstrate that the flux PDF can potentially provide evidence for an unresolved MSP-like point-source population.
27 pages, 8 figures; v2, reference added and other minor changes
References in corpus (25)
- Bayes in the sky: Bayesian inference and model selection in cosmology
- Giant Gamma-ray Bubbles from Fermi-LAT: AGN Activity or Bipolar Galactic Wind?
- Background model systematics for the Fermi GeV excess
- The Spectrum and Morphology of the Fermi Bubbles
- A Tale of Tails: Dark Matter Interpretations of the Fermi GeV Excess in Light of Background Model Systematics
- Cosmic Ray Protons in the Inner Galaxy and the Galactic Center Gamma-Ray Excess
- A Comprehensive Search for Dark Matter Annihilation in Dwarf Galaxies
- Galactic Center gamma-ray "excess" from an active past of the Galactic Centre?
- Millisecond pulsars and the Galactic Center gamma-ray excess: the importance of luminosity function and secondary emission
- Present and future evidence for evolving dark energy
- Updated cosmic-ray and radio constraints on light dark matter: Implications for the GeV gamma-ray excess at the Galactic center
- Millisecond pulsar interpretation of the Galactic center gamma-ray excess
- What Does The PAMELA Antiproton Spectrum Tell Us About Dark Matter?
- Antiproton constraints on the GeV gamma-ray excess: a comprehensive analysis
- Diffuse gamma-ray emission from galactic pulsars
- A study of the population of LMXBs in the bulge of M31
- The Gamma-Ray-Flux Probability Distribution Function from Galactic Halo Substructure
- Testing the millisecond pulsar scenario of the Galactic center gamma-ray excess with very high energy gamma-rays
- PANGU: A High Resolution Gamma-ray Space Telescope
- Bounds on dark matter interpretation of Fermi-LAT GeV excess
- Constraining Dark Matter in Galactic Substructure
- Six Faint Gamma-ray Pulsars Seen with the Fermi Large Area Telescope -- Towards a Sample Blending into the Background
- Sharper Fermi LAT Images: instrument response functions for an improved event selection
- Why the distance of PSR J0218+4232 does not challenge pulsar emission theories
- Antiproton signatures from astrophysical and dark matter sources at the galactic center
Cited by in corpus (12)
- The Return of the Templates: Revisiting the Galactic Center Excess with Multi-Messenger Observations
- Point Sources from Dissipative Dark Matter
- Luminosity functions consistent with a pulsar-dominated Galactic Center Excess
- Molecular Clouds as the Origin of the Fermi Gamma-Ray GeV-Excess
- Probing the pulsar explanation of the Galactic-Center GeV excess using continuous gravitational-wave searches
- Towards resolving the Galactic center GeV excess with millisecond-pulsar-like sources using machine learning
- Characteristic Functions for Cosmological Cross-Correlations
- Extracting the gamma-ray source-count distribution below the Fermi-LAT detection limit with deep learning
- Diffuse X-Ray and Gamma-Ray Limits on Boson Stars that Interact with Nuclei
- Characterizing the Expected Behavior of Non-Poissonian Template Fitting
- On the Energy Distribution of the Galactic Center Excess' Sources
- 4-8 GHz Fourier-domain Searches for Galactic Center Pulsars