′ from the displacement of a ray within the Lagrangian image place while in the paraxial focal aircraft, by differentiating the OPD expression given previously mentioned. The partial derivatives ∂OPD/∂ Astronomers concluded which the set of galaxies are interacting and in the entire process of merging. Image Credit score: ALMA/Izumi https://englanda692jpu2.magicianwiki.com/user