Galactic seismology : can the Gaia ‘phase spiral’ co-exist with a clumpy, turbulent interstellar medium?
The Gaia satellite revealed a remarkable spiral pattern (‘phase spiral’, PS) in the z–Vz phase–plane throughout the solar neighbourhood, where z and Vz are the displacement and velocity of a star perpendicular to the Galactic plane. As demonstrated by many groups, the kinematic signature reflects the Galactic stellar disc’s response to a dynamical disturbance some 0.3–3 Gyr ago. However, previous
