Speaker
Description
High-energy gamma-ray observations are powerful in probing dark matter of m$\gtrsim{\cal O}$(1)TeV. In this context, dwarf spheroidal galaxies (dSphs) are well-motivated targets because dynamical studies indicate that they are highly dark-matter dominated while exhibiting little or no gamma-ray emission from conventional astrophysical processes. One must carefully consider dark matter distributions in these systems for discussing constraints on annihilation cross-sections using gamma-ray data. Most previous studies have assumed spherical dark matter halos, despite the fact that the stellar components of those galaxies generally exhibit ellipticity. Such non-sphericity may have impacts on annihilation signal searches with the Cherenkov Telescope Array Observatory (CTAO), whose angular resolution is finer than the typical angular extent of nearby dSphs. In this talk, we quantify the impacts of the non-sphericity for CTAO observations of dSphs by applying axisymmetric models from non-spherical Jeans analysis of target galaxies, and discuss the implications for future observations.