Inverse Compton Gamma Rays from Dark Matter Annihilation in the Dwarf Galaxies

2016 ◽  
Vol 37 (3) ◽  
Author(s):  
Jayashri Medhi ◽  
H. L. Duorah ◽  
A. G. Barua ◽  
K. Duorah
Keyword(s):  
Dark Matter ◽  
Gamma Rays ◽  
Dwarf Galaxies ◽  
Dark Matter Annihilation ◽  
Inverse Compton

scholarly journals Formation of massive globular clusters with dark matter and its implication on dark matter annihilation

2020 ◽  
Vol 496 (1) ◽  
pp. L70-L74
Author(s):  
Henriette Wirth ◽  
Kenji Bekki ◽  
Kohei Hayashi
Keyword(s):  
Dark Matter ◽  
Observational Studies ◽  
Globular Clusters ◽  
Galactic Halo ◽  
Dwarf Galaxies ◽  
Large Range ◽  
Dark Matter Annihilation ◽  
Central Regions ◽  
Γ Ray ◽  
The Masses

ABSTRACT Recent observational studies of γ-ray emission from massive globular clusters (GCs) have revealed possible evidence of dark matter (DM) annihilation within GCs. It is, however, still controversial whether the emission comes from DM or from millisecond pulsars. We here present the new results of numerical simulations, which demonstrate that GCs with DM can originate from nucleated dwarfs orbiting the ancient Milky Way. The simulated stripped nuclei (i.e. GCs) have the central DM densities ranging from 0.1 to several M⊙ pc−3, depending on the orbits and the masses of the host dwarf galaxies. However, GCs born outside the central regions of their hosts can have no/little DM after their hosts are destroyed and the GCs become the Galactic halo GCs. These results suggest that only GCs originating from stellar nuclei of dwarfs can possibly have DM. We further calculate the expected γ-ray emission from these simulated GCs and compare them to observations of ω Cen. Given the large range of DM densities in the simulated GCs, we suggest that the recent possible detection of DM annihilation from GCs should be more carefully interpreted.

scholarly journals A MODEL-INDEPENDENT METHOD TO STUDY DARK MATTER INDUCED LEPTONS AND GAMMA RAYS

2012 ◽  
Vol 27 (35) ◽  
pp. 1250206 ◽  
Author(s):  
MINGXING LUO ◽  
LIUCHENG WANG ◽  
GUOHUAI ZHU
Keyword(s):  
Dark Matter ◽  
Compton Scattering ◽  
Gamma Rays ◽  
Particle Physics ◽  
Cosmic Ray ◽  
Propagation Model ◽  
Strong Constraint ◽  
Inverse Compton Scattering ◽  
Inverse Compton ◽  
Model Independent

By using recent data, we directly determine the dark matter (DM)-induced e± spectrum at the source from experimental measurements at the earth, without reference to specific particle physics models. The DM-induced gamma rays emitted via inverse Compton scattering are then obtained in a model-independent way. However, the results depend on the choice of the astrophysical e± background, which is not reliably known. Nevertheless, we calculate, as an illustration, the fluxes of gamma rays from the Fornax cluster in the decaying DM scenario with various astrophysical e± backgrounds. Without any assumptions on details of the DM model, the predictions turn out to be either in disagreement with or only marginally below the upper limits measured recently by the Fermi-LAT Collaboration. In addition, these DM-induced ICS gamma rays in the GeV range are shown to be almost independent of choices of cosmic ray propagation model and of DM density profile, when a given astrophysical e± background is assumed. This provides a strong constraint on decaying DM scenario as the gamma rays may be produced in other processes besides inverse Compton scattering, such as the bremsstrahlung and neutral pion decays.

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