Milky Way may have a huge hidden neighbour

2019-03-08 07:14:08

By Ken Croswell A LARGE satellite galaxy may be lurking, hidden from view, next door to our own. Sukanya Chakrabarti and Leo Blitz of the University of California, Berkeley, suspected that the gravity of a nearby galaxy was causing perturbations that have been observed in gas on the fringes of the Milky Way. “We did a large range of simulations where we varied the mass of the perturber and the distance of closest approach,” says Chakrabarti. In the best-fitting simulation, the unseen galaxy has about 1 per cent of the Milky Way’s mass,