Are the Galaxies with Indefinitely Flat Circular Velocities Located Inside Large Dark Matter Haloes?

Abstract

A recent study using weak gravitational lensing revealed that the rotation curves of some isolated galaxies are found at a very large distance from their galactic centres. This may provide strong evidence supporting Modified Newtonian Dynamics (MOND) and challenging the standard cold dark matter model. In this article, we propose the possibility that these isolated galaxies are possibly located at the centres of corresponding large dark matter haloes. Using the standard gravitational framework of galaxy groups and galaxy clusters, we show that this scenario can reproduce the observed rotation curves, provided the existence of corresponding hot gas haloes extending beyond 1 Mpc. Therefore, MOND may not be the only solution to the observed rotation curves and the cold dark matter interpretation still remains viable.

Keywords

• dark matter