The quest for dark matter in dwarf spheroidal galaxies with the Cherenkov Telescope Array

Abstract

Dwarf spheroidal galaxies are among the best environments that can be studied with Cherenkov telescopes for indirect searches of γ-ray signals coming from dark matter self-interaction (annihilation or decay), due to their proximity and negligible background emission. We present new determinations of the dark-matter amount -i.e. the astrophysical factors J and D -in dwarf-galaxy halos obtained through the MCMC Jeans analysis of their brightness and kinematic data. Such factors are of great importance to test the performances of the next-generation γ-ray instruments such as the Cherenkov Telescope Array in detecting dark-matter signals from astronomical environments, or constraining the limits to dark-matter physics parameters (particle mass and lifetime, annihilation cross section).

On self-gravitating strange dark matter halos around galaxies

“…In order to highlight the structural and physical similarities between dSph and MW DM halos, we derive the amount of DM in a sample of selected dSphs by analyzing the kinematics of their member stars. To this end, we apply the Markov-Chain Monte Carlo (MCMC) Jeans analysis integrated in the CLUMPY 2 software [70-72] and described in [73] to the dSphs analyzed by [13], with the inclusion of Carina (Car), Tucana II (Tuc II) and Ursa Minor (UMi) and the removal of Triangulum II (Tri II; see [74,75]). We present the list of selected targets in Tab.…”

“…Recently, a framework for (indirect) search of DM signals also arises in astrophysics from the possibility that DM particles self -interact via annihilation or decay to produce SM pairs [13], that subsequently annihilate into final-state photons (e.g. [14,15]).…”

Discovery prospects of dwarf spheroidal galaxies for indirect dark matter searches

“…Although no discovery has yet been made, the indirect dark matter detection remains one of the most promising search methods [4]. Current gamma-ray telescopes such as the Fermi Large Area Telescope (LAT) [5,6] have so far been able to probe down to the thermal WIMP annihilation cross section for dark matter particles below 100 GeV [7][8][9][10], while the upcoming Cherenkov Telescope Array (CTA) will probe unexplored regions of WIMP parameter space for TeV dark matter [11,12], where many interesting dark matter candidates have been proposed (e.g. [13][14][15]).…”