It's not easy to define a gravitational acceleration for the milky way since for planets it's defined on the surface and the milky way has no clear boundary per

It's not easy to define a gravitational acceleration for the milky way since for planets it's defined on the surface and the milky way has no clear boundary per se. That said, the escape velocity of our galaxy is 537 km/s; almost 50 times that of the earth. Most of it is due to dark matter. https://www.newscientist.com/article/dn24249-stars-escape-velocity-shows-how-to-exit-the-milky-way/ https://www.newscientist.com/article/dn24249-stars-escape-ve...