摘要:With Gaia EDR3 data, velocity dispersion of Milky Way field stars around satellite galaxies has been investigated. We have fitted velocity dispersion against the distance to the satellite galaxy and found the gradient of velocity dispersion is related to the mass of the satellite galaxy. With order-of-magnitude approximations, a linear correlation has been fitted between the mass of the satellite galaxy and the gradient of velocity dispersion caused by its gravitational drag. Though our result is an observational qualitative result, it shows a better relation could be obtained with more observations in the future.