Dark matter searches with Cherenkov telescopes: nearby dwarf galaxies or local galaxy clusters?

Late time decay of very heavy dark matter is considered as one of the possible explanations for diffuse PeV neutrinos observed in IceCube. We consider implications of multimessenger constraints, and show that proposed models are marginally consistent with the diffuse γ-ray background data. Critical tests are possible by a detailed analysis and identification of the sub-TeV isotropic diffuse γ-ray data observed by Fermi and future observations of sub-PeV γ rays by observatories like HAWC or Tibet AS þ MD. In addition, with several-year observations by next-generation telescopes such as IceCube-Gen2, muon neutrino searches for nearby dark matter halos such as the Virgo cluster should allow us to rule out or support the dark matter models, independently of γ-ray and anisotropy tests.

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“…[56], we examine five nearby clusters (Virgo, Fornax, Perseus, Coma, Ophiuchus) using parameters provided in Ref. [74]. In addition, nearby FIG.…”

Section: H Y S I C a L R E V I E W L E T T E R S Week Ending 14 Augusmentioning

confidence: 99%

Testing the Dark Matter Scenario for PeV Neutrinos Observed in IceCube

et al. 2015

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“…The Draco and Ursa Minor profiles are very similar within 600 pc, consistent with an NFW [46] profile with M 200 = 3 − 30 × 10 9 M ⊙ 4 , and a scale radius determined by the WMAP5 massconcentration relation [47]. Within apertures of 7.7 ′ -the region from which most of the source flux originates -and for distances of 77 (Ursa Minor) and 76 (Draco) kpc [42] the corresponding dark matter surface density for a (tidal) truncation radius of 1.5 kpc [48] is ∼ 150 ± 50 M ⊙ pc −2 for each galaxy, where the cutoff is implemented using the "n = 2 BMO" generalization of the NFW profile [49]. Including an additional summed Milky Way contribution of ∼ 150 M ⊙ pc −2 [50], we adopt a fiducial summed, total line-of-sight surface mass density Σ dm = 450 M ⊙ pc −2 , mindful that there is an uncertainty of at least 100 M ⊙ pc −2 .…”

Section: B Data Reduction Spectral Analysis and Line Flux Limitsmentioning

confidence: 99%

Moduli dark matter and the search for its decay line using Suzaku x-ray telescope

2013

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“…We defer any such analysis to future work. The presence of a central gamma-ray emitting source at energies <600 GeV, combined with the expected flat dark matter annihilation emission profile out to the virial radius owing to the substructures that dominate the cluster emission (Sánchez-Conde et al 2011;Pinzke et al 2011;Gao et al 2012), calls for novel analysis techniques that are beyond the scope of the present study.…”

Section: Introductionmentioning

confidence: 99%

“…Here, we focus on the CR induced gamma-ray emission from the cluster itself. Galaxy clusters are also very promising targets for constraining the dark matter annihilation cross section or decay rate (Colafrancesco et al 2006;Pinzke et al 2009;Jeltema et al 2009;Cuesta et al 2011;Dugger et al 2010;Sánchez-Conde et al 2011;Pinzke et al 2011;Gao et al 2012). We defer any such analysis to future work.…”

Section: Introductionmentioning

confidence: 99%

Constraining cosmic rays and magnetic fields in the Perseus galaxy cluster with TeV observations by the MAGIC telescopes

Aleksić

Álvarez

Antonelli

et al. 2012

A&A

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Galaxy clusters are being assembled today in the most energetic phase of hierarchical structure formation which manifests itself in powerful shocks that contribute to a substantial energy density of cosmic rays (CRs). Hence, clusters are expected to be luminous gamma-ray emitters since they also act as energy reservoirs for additional CR sources, such as active galactic nuclei and supernova-driven galactic winds. To detect the gamma-ray emission from CR interactions with the ambient cluster gas, we conducted the deepest to date observational campaign targeting a galaxy cluster at very high-energy gamma-rays and observed the Perseus cluster with the MAGIC Cherenkov telescopes for a total of ∼85 h of effective observing time. This campaign resulted in the detection of the central radio galaxy NGC 1275 at energies E > 100 GeV with a very steep energy spectrum. Here, we restrict our analysis to energies E > 630 GeV and detect no significant gamma-ray excess. This constrains the average CR-to-thermal pressure ratio to be 1-2%, depending on assumptions and the model for CR emission. Comparing these gamma-ray upper limits to models inferred from cosmological cluster simulations that include CRs constrains the maximum CR acceleration efficiency at structure formation shocks to be <50%. Alternatively, this may argue for non-negligible CR transport processes such as CR streaming and diffusion into the outer cluster regions. Finally, we derive lower limits on the magnetic field distribution assuming that the Perseus radio mini-halo is generated by secondary electrons/positrons that are created in hadronic CR interactions: assuming a spectrum of E −2.2 around TeV energies as implied by cluster simulations, we limit the central magnetic field to be >4-9 μG, depending on the rate of decline of the magnetic field strength toward larger radii. This range is well below field strengths inferred from Faraday rotation measurements in cool cores. Hence, the hadronic model remains a plausible explanation of the Perseus radio mini-halo.

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Dark matter searches with Cherenkov telescopes: nearby dwarf galaxies or local galaxy clusters?

Cited by 105 publications

References 199 publications

Testing the Dark Matter Scenario for PeV Neutrinos Observed in IceCube

Testing the Dark Matter Scenario for PeV Neutrinos Observed in IceCube

Moduli dark matter and the search for its decay line using Suzaku x-ray telescope

Constraining cosmic rays and magnetic fields in the Perseus galaxy cluster with TeV observations by the MAGIC telescopes

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