... Gravitational wave search provides insights into galaxy evolution and mergers . ... galaxies . ... Galaxies fed by funnels of fuel . Computer simulations of galaxies show that cold gas spirals into the cores of galaxies along filaments, rapidly making its way to their guts. ... The results show that cold gas fuel for stars spirals into the cores of galaxies along filaments, rapidly making its way to their guts. Once there, the gas is converted into new stars, and the galaxies bulk up in mass. ...