Dark-matter central density, annihilation J-factor and decay D-factor of the Fornax, Sculptor and Leo I dwarf spheroidal galaxies

TL;DR

This paper models the dark matter halos of three dwarf spheroidal galaxies to estimate their central densities and factors relevant for indirect dark matter detection, providing insights into their dark matter distribution.

Contribution

It introduces dynamical models based on distribution functions with action integrals to accurately estimate dark matter properties of these galaxies.

Findings

Fornax has the highest J- and D-factors among the three galaxies.

Leo I has the highest central dark matter density rho150.

Fornax's low rho150 contrasts with its high annihilation and decay factors.

Abstract

The dwarf spheroidal galaxies (dSphs) satellites of the Milky Way (MW) are nearby astrophysical laboratories to study the nature of dark matter (DM). We present some properties of the DM halos of the three classical dSphs Fornax, Sculptor and Leo I, obtained using dynamical models based on distribution functions depending on the action integrals. In particular, we report accurate estimates of their central DM density rho150 (measured at a distance of 150 pc from the galaxy centre), which is relevant for galaxy formation studies and for models of self-interacting DM, and their DM annihilation J-factor and decay D-factor, which are key tools for indirect DM detection experiments. Among these three galaxies, Fornax has the highest J- and D- factors (but the lowest rho150), while Leo I has the highest rho150 (but the lowest J- and D- factors).