La Silla QUEST RR Lyrae Star Survey: Region I
  A search for RR Lyrae stars (RRLS) in 840 sq.deg. of the sky in right
ascension 150 - 210 deg and declination -10 - +10 deg yielded 1013 type ab and
359 type c RRLS. This sample is used to study the density profile of the
Galactic halo, halo substructures, and the Oosterhoff type of the halo over
distances from 5 to 80 kpc. The halo is flattened towards the Galactic plane,
and its density profile steepens in slope at galactocentric distances greater
than 25 kpc. The RRLS in the stellar stream from the Sagittarius dwarf
spheroidal (dSph) galaxy match well the model of Law and Majewski for the stars
that were stripped 1.3 to 3.2 Gyr ago, but not for the ones stripped 3.2 to 5.0
Gyr ago. Over densities are found at the locations of the Virgo Overdensity and
the Virgo Stellar Stream. Within 1 deg of 1220-1, which Jerjen et al. identify
as a halo substructure at a distance of 24 kpc, there are 4 RRLS that are
possibly members. Away from substructures, the RRLS are a mixture of Oosterhoff
types I and II, but mostly OoI (73%). The accretion of galaxies resembling in
RRLS content the most massive Milky Way satellites (LMC, SMC, For,Sgr) may
explain this preponderance of OoI. Six new RRLS and 3 new anomalous Cepheids
were found in the Sextans dSph galaxy.
