In recent years the Sloan Digital Sky Survey has unraveled a new population of ultra-faint dwarf galaxies ( UFDs ) in the vicinity of the Milky Way ( MW ) whose origin remains a puzzle .
Using a suite of collisionless N -body simulations , we investigate the formation of UFDs in the context of the tidal stirring model for the formation of dwarf spheroidal galaxies in the Local Group ( LG ) .
Our simulations are designed to reproduce the tidal interactions between MW-sized host galaxies and rotationally supported dwarfs embedded in 10 ^ { 9 } M _ { \odot } dark matter ( DM ) halos .
We explore a variety of inner density slopes \rho \propto r ^ { - \alpha } for the dwarf DM halos , ranging from core-like ( \alpha = 0.2 ) to cuspy ( \alpha = 1 ) , and different dwarf orbital configurations .
Our experiments demonstrate that UFDs can be produced via tidal stirring of disky dwarfs on relatively tight orbits , consistent with a redshift of accretion by the host galaxy of z \sim 1 , and with intermediate values for the halo inner density slopes ( \rho \propto r ^ { -0.6 } ) .
The inferred slopes are in excellent agreement with those resulting from both the modeling of the rotation curves of dwarf galaxies and recent cosmological simulations of dwarf galaxy formation .
Comparing the properties of observed UFDs with those of their simulated counterparts , we find remarkable similarities in terms of basic observational parameters .
We conclude that tidal stirring of rotationally supported dwarfs represents a viable mechanism for the formation of UFDs in the LG environment .