2020A&A...634L...8K

In this paper we introduce a new method for analysing Milky Way phase-space which allows us to reveal the imprint left by the Milky Way bar and spiral arms on the stars with full phase-space data in Gaia Data Release 2. The unprecedented quality and extended spatial coverage of these data allowed us to discover six prominent stellar density structures in the disc to a distance of 5kpc from the Sun. Four of these structures correspond to the spiral arms detected previously in the gas and young stars (Scutum-Centaurus, Sagittarius, Local, and Perseus). The remaining two are associated with the main resonances of the Milky Way bar where corotation is placed at around 6.2kpc and the outer Lindblad resonance beyond the solar radius, at around 9kpc. For the first time we provide evidence of the imprint left by spiral arms and resonances in the stellar densities not relying on a specific tracer, through enhancing the signatures left by these asymmetries. Our method offers new avenues for studying how the stellar populations in our Galaxy are shaped.