The Tidal Evolution of Local Group Dwarf Spheroidals

Understand

(Abridged) We use N-body simulations to study the evolution of dwarf spheroidal galaxies (dSphs) driven by galactic tides.

• We adopt a cosmologically-motivated model where dSphs are approximated by a King model embedded within an NFW halo.
• We find that these NFW-embedded King models are extraordinarily resilient to tides; the stellar density profile still resembles a King model even after losing more than 99% of the stars.
• As tides strip the galaxy, the stellar luminosity, velocity dispersion, central surface brightness, and core radius decrease monotonically.