Full 5D characterisation of the Sagittarius stream with Gaia DR2 RR Lyrae

Understand

The Sagittarius stream is one of the best tools that we currently have to estimate the mass and shape of our Galaxy.

• However, assigning membership and obtaining the phase-space distribution of the stars that form the tails is quite challenging.
• Our goal is to produce a catalogue of RR Lyrae stars of Sagittarius and obtain an empiric measurement of the trends along the stream in sky position, distance and tangential velocities.
• We generate two initial samples from the Gaia DR2 RR Lyrae catalogue: one, selecting only the stars within \pm20deg of the orbital plane of Sagittarius (Strip) and the other, the result of applying the Pole Count Map (nGC3) algorithm.