Sub-structures in the inner halo of the Milky Way

Abstract

We present a spectroscopic study of a sample of 238 RR Lyrae stars, from the QUEST survey, located in the Galactic halo at distances between 4 and 20 kpc from the Sun. Combining their spatial position and kinematics we were able to identify sub-structures in this part of the halo. Some of those sub-structures may be associated with known halo features like the Virgo Overdensity, the Hercules-Aquila Cloud, and the Anticenter Stream.