Tracing the Milky Way spiral arms. Now and in the Gaia era:Now and in the Gaia era

Whereas it is well established that spiral arms are important agents driving the evolution of the galactic disks, the observational evidences of the outer spiral arms in our Milky Way are frustratingly inconclusive. In order to shed some light on the still remaining open questions, we are developing a photometric and spectroscopic survey in the anticenter direction with the aim to detect the overdensity and the kinematic perturbation due to the Perseus arm. We show how preliminary Strömgren photometric data from B5-A3 stars suggest an overdensity at 1.5-2 kpc from the Sun, probably related with the Perseus arm. The photometric data already obtained is being used to select the targets for the spectroscopic survey. Radial velocities will be used to evaluate the amplitude of the kinematic perturbation due to the arm. We also present our first simulations to evaluate the capabilities of Gaia data and the already developed tools to derive the parameters of the density wave in the solar neighborhood