A Prescription for Building the Milky Way's Halo from Disrupted Satellites

We develop a semi-analytic method for determining the phase-space populationof tidal debris along the orbit of a disrupting satellite galaxy and illustrateits use with a number of applications. We use this method to analyze Zhao'sproposal that the microlensing events towards the Large Magellanic Cloud (LMC)might be explained by an appropriately placed tidal streamer, and find that hisscenarios lead either to unacceptably high overdensities (10 -- 100%) in faintstar counts (apparent magnitudes 17.5 -- 20.5) away from the Galactic plane orshort timescales for the debris to disperse (10^8 years). We predict that thetidal streamers from the LMC and the Sagittarius dwarf galaxy currently extendover more than $2\pi$ in azimuth along their orbits. Assuming that eachsatellite has lost half of its primordial mass, we find that the streamers willhave overdensities in faint star counts of 10 -- 100% and < 1% respectively,and conclude that this mass loss rate is unlikely for the LMC, but possible forSagittarius. If the Galaxy has accreted one hundred $10^5-10^6 M_{\odot}$objects (comparable to its current population of globular clusters) atdistances of 20 -- 100 kpc during its lifetime then 10% of the sky will now becovered by tidal streamers.Comment: 35 pages, LaTeX, 12 postscript figures included. Submitted to Ap