scholarly journals Connecting the new H.E.S.S. diffuse emission at the Galactic Center with the Fermi GeV excess: A combination of millisecond pulsars and heavy dark matter?

2016 ◽  
Vol 94 (12) ◽  
Author(s):  
Thomas Lacroix ◽  
Joseph Silk ◽  
Emmanuel Moulin ◽  
Céline Bœhm
Keyword(s):  
Dark Matter ◽  
Galactic Center ◽  
Diffuse Emission ◽  
Millisecond Pulsars

Resolved Millisecond Pulsars are Consistent with the Galactic Center Excess (Invited Talk)

2018 ◽  
Author(s):  
Chris Gordon ◽  
Harrison Ploeg ◽  
Roland Crocker ◽  
Oscar Macias
Keyword(s):  
Galactic Center ◽  
Millisecond Pulsars

scholarly journals Spin-one dark matter and gamma ray signals from the galactic center

2020 ◽  
Vol 2020 (8) ◽  
Author(s):  
H. Hernández-Arellano ◽  
M. Napsuciale ◽  
S. Rodríguez
Keyword(s):  
Dark Matter ◽  
Cross Section ◽  
Gamma Ray ◽  
Galactic Center ◽  
Photon Emission ◽  
Scalar Coupling ◽  
Initial State ◽  
Internal Bremsstrahlung ◽  
Resonance Effects ◽  
State Radiation

Abstract In this work we study the possibility that the gamma ray excess (GRE) at the Milky Way galactic center come from the annihilation of dark matter with a (1, 0) ⊕ (0, 1) space-time structure (spin-one dark matter, SODM). We calculate the production of prompt photons from initial state radiation, internal bremsstrahlung, final state radiation including the emission from the decay products of the μ, τ or hadronization of quarks. Next we study the delayed photon emission from the inverse Compton scattering (ICS) of electrons (produced directly or in the prompt decay of μ, τ leptons or in the hadronization of quarks produced in the annihilation of SODM) with the cosmic microwave background or starlight. All these mechanisms yield significant contributions only for Higgs resonant exchange, i.e. for M ≈ MH /2, and the results depend on the Higgs scalar coupling to SODM, gs. The dominant mechanism at the GRE bump is the prompt photon production in the hadronization of b quarks produced in $$ \overline{D}D\to \overline{b}b $$ D ¯ D → b ¯ b , whereas the delayed photon emission from the ICS of electrons coming from the hadronization of b quarks produced in the same reaction dominates at low energies (ω < 0.3 GeV ) and prompt photons from c and τ , as well as from internal bremsstrahlung, yield competitive contributions at the end point of the spectrum (ω ≥ 30 GeV ). Taking into account all these contributions, our results for photons produced in the annihilation of SODM are in good agreement with the GRE data for gs ∈ [0.98, 1.01] × 10−3 and M ∈ [62.470, 62.505] GeV . We study the consistency of the corresponding results for the dark matter relic density, the spin-independent dark matter-nucleon cross-section σp and the cross section for the annihilation of dark matter into $$ \overline{b}b $$ b ¯ b , τ+τ−, μ+μ− and γγ, taking into account the Higgs resonance effects, finding consistent results in all cases.

scholarly journals On a Possible Origin of the Gamma-ray Excess around the Galactic Center

Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1432
Author(s):  
Dmitry O. Chernyshov ◽  
Andrei E. Egorov ◽  
Vladimir A. Dogiel ◽  
Alexei V. Ivlev
Keyword(s):  
Dark Matter ◽  
Gamma Rays ◽  
Molecular Clouds ◽  
Alternative Explanation ◽  
Gamma Ray ◽  
Galactic Center ◽  
The Self ◽  
Large Area ◽  
Mhd Turbulence ◽  
The Standard Model

Recent observations of gamma rays with the Fermi Large Area Telescope (LAT) in the direction of the inner galaxy revealed a mysterious excess of GeV. Its intensity is significantly above predictions of the standard model of cosmic rays (CRs) generation and propagation with a peak in the spectrum around a few GeV. Popular interpretations of this excess are that it is due to either spherically distributed annihilating dark matter (DM) or an abnormal population of millisecond pulsars. We suggest an alternative explanation of the excess through the CR interactions with molecular clouds in the Galactic Center (GC) region. We assumed that the excess could be imitated by the emission of molecular clouds with depleted density of CRs with energies below ∼10 GeV inside. A novelty of our work is in detailed elaboration of the depletion mechanism of CRs with the mentioned energies through the “barrier” near the cloud edge formed by the self-excited MHD turbulence. This depletion of CRs inside the clouds may be a reason for the deficit of gamma rays from the Central Molecular Zone (CMZ) at energies below a few GeV. This in turn changes the ratio between various emission components at those energies and may potentially absorb the GeV excess by a simple renormalization of key components.

scholarly journals DARK MATTER DYNAMICS AND INDIRECT DETECTION

2005 ◽  
Vol 20 (14) ◽  
pp. 1021-1036 ◽  
Author(s):  
GIANFRANCO BERTONE ◽  
DAVID MERRITT
Keyword(s):  
Dark Matter ◽  
Total Mass ◽  
Galactic Center ◽  
Direct Detection ◽  
Indirect Detection ◽  
Matter Distribution ◽  
Dark Matter Distribution ◽  
Particle Dark Matter ◽  
The Universe ◽  
Rule Out

Non-baryonic, or "dark", matter is believed to be a major component of the total mass budget of the Universe. We review the candidates for particle dark matter and discuss the prospects for direct detection (via interaction of dark matter particles with laboratory detectors) and indirect detection (via observations of the products of dark matter self-annihilations), focusing in particular on the Galactic center, which is among the most promising targets for indirect detection studies. The gravitational potential at the Galactic center is dominated by stars and by the supermassive black hole, and the dark matter distribution is expected to evolve on sub-parsec scales due to interaction with these components. We discuss the dominant interaction mechanisms and show how they can be used to rule out certain extreme models for the dark matter distribution, thus increasing the information that can be gleaned from indirect detection searches.

DARK MATTER SEARCH WITH GAMMA RAYS: THE EXPERIMENTS EGRET AND GLAST

2002 ◽  
Vol 17 (12n13) ◽  
pp. 1829-1840 ◽  
Author(s):  
ALDO MORSELLI
Keyword(s):  
Dark Matter ◽  
Cosmic Rays ◽  
Standard Model ◽  
Supersymmetric Standard Model ◽  
Minimal Supersymmetric Standard Model ◽  
Gamma Rays ◽  
Galactic Center ◽  
Direct Detection ◽  
Model Parameters ◽  
Dark Matter Search

The direct detection of annihilation products in cosmic rays offers an alternative way to search for supersymmetric dark matter particles candidates. The study of the spectrum of gamma-rays, antiprotons and positrons offers good possibilities to perform this search in a significant portion of the Minimal Supersymmetric Standard Model parameters space. In particular the EGRET team have seen a convincing signal for a strong excess of emission from the galactic center that have not easily explanation with standard processes. We will review the achievable limits with the experiment GLAST taking into accounts the LEP results and we will compare this method with the antiproton and positrons experiments, the direct underground detection and with future experiments at LHC.

scholarly journals TWO COMPONENTS OF DARK MATTER IN THE DAMA DATA

2008 ◽  
Vol 23 (30) ◽  
pp. 4811-4816 ◽  
Author(s):  
YUKIO TOMOZAWA
Keyword(s):  
Dark Matter ◽  
Galactic Center ◽  
Yearly Variation

It is shown that the DAMA data indicate two dark matter components, one that circulates around the galactic center (GC) and another that is emitted from the GC. From the location of the maximum yearly variation, one can compute the ratio of the two components.

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