SIMBAD references

We study the mass spectrum of destroyed dwarfs that contribute to the accreted stellar mass of Milky Way (MW)-mass (Mvir ∼ 1012.1M☉) halos using a suite of 45 zoom-in dissipationless simulations. Empirical models are employed to relate (peak) subhalo mass to dwarf stellar mass, and we use constraints from z = 0 observations and hydrodynamical simulations to estimate the metallicity distribution of the accreted stellar material. The dominant contributors to the accreted stellar mass are relatively massive dwarfs with Mstar ∼ 108-1010M☉. Halos with more quiescent accretion histories tend to have lower mass progenitors (108-109M☉), and lower overall accreted stellar masses. Ultra-faint mass (Mstar < 105M☉) dwarfs contribute a negligible amount (≪1%) to the accreted stellar mass and, despite having low average metallicities, supply a small fraction (∼2%-5%) of the very metal-poor stars with [Fe/H] < -2. Dwarfs with masses 105 < Mstar/M☉ < 108 provide a substantial amount of the very metal-poor stellar material (∼40%-80%), and even relatively metal-rich dwarfs with Mstar > 108M☉ can contribute a considerable fraction (∼20%-60%) of metal-poor stars if their metallicity distributions have significant metal-poor tails. Finally, we find that the generic assumption of a quiescent assembly history for the MW halo seems to be in tension with the mass spectrum of its surviving dwarfs. We suggest that the MW could be a "transient fossil"; a quiescent halo with a recent accretion event(s) that disguises the preceding formation history of the halo.