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Title: Fermi 130 GeV gamma-ray excess and dark matter annihilation in sub-haloes and in the Galactic centre

Abstract

We analyze publicly available Fermi-LAT high-energy gamma-ray data and confirm the existence of clear spectral feature peaked at E{sub γ} = 130 GeV. Scanning over the Galaxy we identify several disconnected regions where the observed excess originates from. Our best optimized fit is obtained for the central region of Galaxy with a clear peak at 130 GeV with local statistical significance 4.5σ. The observed excess is not correlated with Fermi bubbles. We compute the photon spectra induced by dark matter annihilations into two and four standard model particles, the latter via two light intermediate states, and fit the spectra with data. Since our fits indicate sharper and higher signal peak than in the previous works, data favors dark matter direct two-body annihilation channels into photons or other channels giving only line-like spectra. If Einasto halo profile correctly predicts the central cusp of Galaxy, dark matter annihilation cross-section to two photons is of order ten percent of the standard thermal freeze-out cross-section. The large dark matter two-body annihilation cross-section to photons may signal a new resonance that should be searched for at the CERN LHC experiments.

Authors:
; ;  [1]
  1. NICPB, Ravala 10, Tallinn 10143 (Estonia)
Publication Date:
OSTI Identifier:
22279951
Resource Type:
Journal Article
Journal Name:
Journal of Cosmology and Astroparticle Physics
Additional Journal Information:
Journal Volume: 2012; Journal Issue: 09; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1475-7516
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ANNIHILATION; ASTROPHYSICS; CERN LHC; COSMOLOGY; CROSS SECTIONS; GAMMA RADIATION; GEV RANGE; INTERMEDIATE STATE; MILKY WAY; NONLUMINOUS MATTER; RESONANCE; SIGNALS; STANDARD MODEL; TWO-BODY PROBLEM

Citation Formats

Tempel, Elmo, Hektor, Andi, and Raidal, Martti. Fermi 130 GeV gamma-ray excess and dark matter annihilation in sub-haloes and in the Galactic centre. United States: N. p., 2012. Web. doi:10.1088/1475-7516/2012/09/032.
Tempel, Elmo, Hektor, Andi, & Raidal, Martti. Fermi 130 GeV gamma-ray excess and dark matter annihilation in sub-haloes and in the Galactic centre. United States. https://doi.org/10.1088/1475-7516/2012/09/032
Tempel, Elmo, Hektor, Andi, and Raidal, Martti. Sat . "Fermi 130 GeV gamma-ray excess and dark matter annihilation in sub-haloes and in the Galactic centre". United States. https://doi.org/10.1088/1475-7516/2012/09/032.
@article{osti_22279951,
title = {Fermi 130 GeV gamma-ray excess and dark matter annihilation in sub-haloes and in the Galactic centre},
author = {Tempel, Elmo and Hektor, Andi and Raidal, Martti},
abstractNote = {We analyze publicly available Fermi-LAT high-energy gamma-ray data and confirm the existence of clear spectral feature peaked at E{sub γ} = 130 GeV. Scanning over the Galaxy we identify several disconnected regions where the observed excess originates from. Our best optimized fit is obtained for the central region of Galaxy with a clear peak at 130 GeV with local statistical significance 4.5σ. The observed excess is not correlated with Fermi bubbles. We compute the photon spectra induced by dark matter annihilations into two and four standard model particles, the latter via two light intermediate states, and fit the spectra with data. Since our fits indicate sharper and higher signal peak than in the previous works, data favors dark matter direct two-body annihilation channels into photons or other channels giving only line-like spectra. If Einasto halo profile correctly predicts the central cusp of Galaxy, dark matter annihilation cross-section to two photons is of order ten percent of the standard thermal freeze-out cross-section. The large dark matter two-body annihilation cross-section to photons may signal a new resonance that should be searched for at the CERN LHC experiments.},
doi = {10.1088/1475-7516/2012/09/032},
url = {https://www.osti.gov/biblio/22279951}, journal = {Journal of Cosmology and Astroparticle Physics},
issn = {1475-7516},
number = 09,
volume = 2012,
place = {United States},
year = {2012},
month = {9}
}