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Glow in the dark matter: observing galactic halos with scattered light
Jonathan H Davis1, Joseph Silk2
1Institut d'Astrophysique de Paris, 98 bis boulevard Arago, 75014 Paris, France and Institute for Particle Physics Phenomenology, Durham University, Durham DH1 3LE, United Kingdom.
Physical Review Letters
|February 21, 2015
Summary
Diffuse halos around spiral galaxies can reveal dark matter-photon interactions. This study sets upper limits on the dark matter-photon cross section using galaxy M101 observations, offering a new probe for dark matter research.
Area of Science:
- Astrophysics
- Cosmology
- Particle Physics
Background:
- Diffuse halos of light around spiral galaxies provide a unique observational target.
- Understanding dark matter (DM) interactions is a key challenge in modern physics.
- The interaction cross section between dark matter and photons is poorly constrained.
Purpose of the Study:
- To use diffuse galactic halos as a probe for dark matter-photon interactions.
- To establish an upper limit on the dark matter-photon scattering cross section.
- To explore methods for improving constraints and potential discovery through multi-wavelength observations.
Main Methods:
- Analyzing the diffuse light distribution in the halo of galaxy M101.
- Modeling the effect of dark matter-photon scattering on surface brightness.
- Utilizing data from the Dragonfly instrument.
Main Results:
- A scattering cross section of 10(-23)(m/GeV) cm(2) or greater predicts observable scattering of light from galactic discs to larger radii.
- An upper limit on the dark matter-photon cross section was derived using M101 data.
- Combining radial profiles with multi-wavelength data can enhance constraints.
Conclusions:
- Diffuse galactic light offers a novel and powerful method to investigate dark matter-photon interactions.
- This approach is complementary to existing dark matter detection strategies.
- Further multi-wavelength observations can significantly improve the sensitivity of this probe.
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