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Description
We use Canada-France-Hawaii Telescope Legacy Survey data for 170deg^2^, recalibrated and transformed to the Sloan Digital Sky Survey ugri photometric system, to study the distribution of near-turnoff main-sequence stars in the Galactic halo along four lines of sight to heliocentric distances of ~35kpc. We find that the halo stellar number density profile becomes steeper at Galactocentric distances greater than R_gal_~28kpc, with the power-law index changing from n_inner_=-2.62+/-0.04 to n_outer_=-3.8+/-0.1. In particular, we test a series of single power-law models and find them to be strongly disfavored by the data. The parameters for the best-fit Einasto profile are n=2.2+/-0.2 and R_e_=22.2+/-0.4kpc. We measure the oblateness of the halo to be q=c/a=0.70+/-0.01 and detect no evidence of it changing across the range of probed distances. The Sagittarius stream is detected in the l=173{deg} and b=-62{deg} direction as an overdensity of [Fe/H]~-1.5dex stars at R_gal_~32kpc, providing a new constraint for the Sagittarius stream and dark matter halo models. We also detect the Monoceros stream as an overdensity of [Fe/H]>-1.5dex stars in the l=232{deg} and b=26{deg} direction at R_gal_<~25kpc. In the two sight lines where we do not detect significant substructure, the median metallicity is found to be independent of distance within systematic uncertainties ([Fe/H]~-1.5+/-0.1dex).
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