The Most Dark‐Matter–dominated Galaxies: Predicted Gamma‐Ray Signals from the Faintest Milky Way Dwarfs

Strigari, Louis E.; Koushiappas, Savvas M.; Bullock, James S.; Kaplinghat, Manoj; Simon, Joshua D.; Geha, Marla; Willman, Beth

doi:10.1086/529488

Cited by 202 publications

(293 citation statements)

References 70 publications

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“…Observations in the hard X-ray band would also be useful; however, as opposed to clusters of galaxies, where the effect of diffusion on the dark matter multiwavelength SED is typically mild (see Colafrancesco et al 2006;Profumo 2008a), in dSph galaxies high-energy electrons and positrons escape more efficiently from the diffusive region, suppressing the hard X-ray emission. Strigari et al (2008) recently estimated the gamma-ray flux from dark matter annihilation in newly discovered, extremely low luminosity and dark matter dominated Milky Way dwarf galaxies. The expected gamma-ray flux from these nearby galaxies may be larger than that from previously known dwarfs, depending on the so far poorly known dark matter density distribution.…”

Section: Summary and Discussionmentioning

confidence: 99%

Searching for Dark Matter with X‐Ray Observations of Local Dwarf Galaxies

Jeltema

Profumo

2008

Astrophysical Journal

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A generic feature of weakly interacting massive particle (WIMP) dark matter models is the emission of photons over a broad energy band resulting from the stable yields of dark matter pair annihilation. Inverse Compton scattering off cosmic microwave background photons of energetic electrons and positrons produced in dark matter annihilation is expected to produce significant diffuse X-ray emission. Dwarf galaxies are ideal targets for this type of dark matter search technique, being nearby, dark matter dominated systems free of any astrophysical diffuse X-ray background. In this paper, we present the first systematic study of X-ray observations of local dwarf galaxies aimed at the search for WIMP dark matter. We outline the optimal energy and angular ranges for current telescopes and analyze the systematic uncertainties connected to electron/positron diffusion. We do not observe any significant X-ray excess, and we translate this null result into limits on the mass and pair annihilation cross section for particle dark matter. Our results indicate that X-ray observations of dwarf galaxies currently constrain dark matter models at the same level as or even more strongly than gamma-ray observations of the same systems, although at the expenses of introducing additional assumptions and related uncertainties in the modeling of diffusion and energy loss processes. The limits we find constrain portions of the supersymmetric parameter space, particularly if the effect of dark matter substructures is included. Finally, we comment on the role of future X-ray satellites (e.g., Constellation-X, XEUS ) and on their complementarity with GLAST and other gamma-ray telescopes in the quest for particle dark matter.

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Section: Summary and Discussionmentioning

confidence: 99%

Searching for Dark Matter with X‐Ray Observations of Local Dwarf Galaxies

Jeltema

Profumo

2008

Astrophysical Journal

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“…Under the assumption of a particular DM density distribution profile, the flux upper limits can be used to set upper bounds on σ A v . Dwarf spheroidal galaxies have the advantage that the integrated J-factor is relatively insensitive to the choice of a DM density profile [31,32]. The bounds on the annihilation cross sections of χ are obtained from the recent results of Fermi-LAT [26] where the negative search of gamma rays coming from 15 dwarf spheroidal satellite galaxies of the Milky Way is used to set upper limits on the DM annihilation cross section into certain channels, namely e + e − , µ + µ − , τ + τ − , uu, bb and W W .…”

Section: Experimental Inputmentioning

confidence: 99%

Singlet-Doublet model: dark matter searches and LHC constraints

Calibbi

Mariotti

Tziveloglou

2015

J. High Energ. Phys.

101

125

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Abstract:The Singlet-Doublet model of dark matter is a minimal extension of the Standard Model with dark matter that is a mixture of a singlet and a non-chiral pair of electroweak doublet fermions. The stability of dark matter is ensured by the typical parity symmetry, and, similar to a 'Bino-Higgsino' system, the extra matter content improves gauge coupling unification. We revisit the experimental constraints on the Singlet-Doublet dark matter model, combining the most relevant bounds from direct (spin independent and spin dependent) and indirect searches. We show that such comprehensive analysis sets strong constraints on a large part of the 4-dimensional parameter space, closing the notorious 'blind-spots' of spin independent direct searches. Our results emphasise the complementarity of direct and indirect searches in probing dark matter models in diverse mass scale regimes. We also discuss the LHC bounds on such scenario, which play a relevant role in the low mass region of the dark matter candidate.

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“…However, it has been argued that effects in the halo distribution alone can only be expected to account for a boost factor of ∼ 2 − 3, due to the uncertainty in the estimation of the local halo abundance [44]. A possible additional factor < ∼ 10 could arise from substructure within the Milky-Way halo [45], and, for signals from dwarf galaxies, there could possibly be a factor < ∼ 100 [46]. In this work we will focus on models that best fit the data with B < 200.…”

Section: Jhep01(2011)064mentioning

confidence: 99%

“…12 Although, as emphasized in [46,103], stellar kinematic data fix the normalization of ρ and ρ 2 such that the detailed nature of the inner-slope of the halo ends up having a relatively small effect on the total halo integral. 13 A rough calculation of these contributions (without any attempt to include the LAT instrument response) showed that the line contribution to the total yield of gammas would be > 1% in only ≈ 0.5% of the models in our pMSSM set.…”

Section: Jhep01(2011)064mentioning

confidence: 99%

Cosmic ray anomalies from the MSSM?

Cotta

Conley

Gainer

et al. 2011

J. High Energ. Phys.

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Abstract:The recent positron excess in cosmic rays (CR) observed by the PAMELA satellite may be a signal for dark matter (DM) annihilation. When these measurements are combined with those from FERMI on the total (e + + e − ) flux and from PAMELA itself on thep/p ratio, these and other results are difficult to reconcile with traditional models of DM, including the conventional mSUGRA version of Supersymmetry even if boosts as large as 10 3−4 are allowed. In this paper, we combine the results of a previously obtained scan over a more general 19-parameter subspace of the MSSM with a corresponding scan over astrophysical parameters that describe the propagation of CR. We then ascertain whether or not a good fit to this CR data can be obtained with relatively small boost factors while simultaneously satisfying the additional constraints arising from gamma ray data. We find that a specific subclass of MSSM models where the LSP is mostly pure bino and annihilates almost exclusively into τ pairs comes very close to satisfying these requirements. The lightestτ in this set of models is found to be relatively close in mass to the LSP and is in some cases the nLSP. These models lead to a significant improvement in the overall fit to the data by an amount ∆χ 2 ∼ 1/dof in comparison to the best fit without Supersymmetry while employing boosts ∼ 100. The implications of these models for future experiments are discussed.

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The Most Dark‐Matter–dominated Galaxies: Predicted Gamma‐Ray Signals from the Faintest Milky Way Dwarfs

Cited by 202 publications

References 70 publications

Searching for Dark Matter with X‐Ray Observations of Local Dwarf Galaxies

Searching for Dark Matter with X‐Ray Observations of Local Dwarf Galaxies

Singlet-Doublet model: dark matter searches and LHC constraints

Cosmic ray anomalies from the MSSM?

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