Optimized Dark Matter Searches in Deep Observations of Segue 1 with MAGIC

Abstract

Abstract. We present the results of stereoscopic observations of the satellite galaxy Segue 1 with the MAGIC Telescopes, carried out between 2011 and 2013. With almost 160 hours of good-quality data, this is the deepest observational campaign on any dwarf galaxy performed so far in the very high energy range of the electromagnetic spectrum. We search this large data sample for signals of dark matter particles in the mass range between 100 GeV and 20 TeV. For this we use the full likelihood analysis method, which provides optimal sensitivity to characteristic gamma-ray spectral features, like those expected from dark matter annihilation or decay. In particular, we focus our search on gamma-rays produced from different final state Standard Model particles, annihilation with internal bremsstrahlung, monochromatic lines and box-shaped signals. Our results represent the most stringent constraints to the annihilation cross-section or decay lifetime obtained from observations of satellite galaxies, for masses above few hundred GeV. In particular, our strongest limit (95% confidence level) corresponds to a ∼500 GeV dark matter particle annihilating into τ + τ − , and is of order σ ann v ≃ 1.2×10 −24 cm 3 s −1 -a factor ∼40 above the σ ann v thermal value.

A review of indirect searches for particle dark matter

“…The currentlyoperating generation of IACTs includes H.E.S.S. (-II), MAGIC, and VERITAS; these telescopes have placed the strongest bounds on signals from dark matter with m χ greater than a few hundred GeV via null searches toward a variety of targets [69][70][71][72]. The planned Cherenkov Telescope Array (CTA) observatory [73], which is anticipated to begin observations within a few years, will provide significantly improved sensitivity to indirect dark matter signals for WIMPs with m χ 100 GeV and is expected to be able to probe thermal relic cross sections for a range of WIMP masses and channels [74][75][76].…”

“…Many Milky Way satellites (dwarf galaxies and low-surface-brightness galaxies) have been evaluated as targets for gamma-ray searches (e.g., [180][181][182][183]), and several have been observed by MAGIC [70] and VERITAS [71,72]. No excesses were observed by these IACTs, and limits on dark matter fluxes were placed.…”

A search for neutrino signal from dark matter annihilation in the center of the Milky Way with Baikal NT200

“…In Fig. 11 we compare upper limits at 90% CL on the τ + τ − annihilation cross section obtained with the NT200 dataset and other experiments including results by the FERMI [54] (dwarf galaxies, DES), VERITAS [55] (four dwarf galaxies), MAGIC [56] νν Expected limit, 95% Expected limit, 68.27% Expected limit Observed limit Figure 9: The upper limits on the annihilation cross section versus DM mass for channels bb (left) and νν (right) at 90% CL (black, solid) and the expected sensitivities (black, dashed) within its 1σ (red band) and 2σ (blue band) levels of statistical uncertainty. : 90% CL upper limits on the dark matter annihilation cross section for νν channel obtained with the NT200 dataset (red line) in this study in comparison with results from ANTARES [16], IceCube [17] and Super-Kamiokande [18].…”

Supersymmetric resonant dark matter: A thermal model for the AMS-02 positron excess

“…Dark matter annihilations have been considered as a potential explanation for the excess in the past. Annihilations into quarks, gluons or electroweak gauge bosons can provide a good fit to the positron data alone, but there are additional stringent constraints from gamma ray searches at VERITAS [38], Fermi-LAT [26], MAGIC [39], and H.E.S.S. [40] that rule out these possibilities by orders of magnitude [23].…”