A galactic vampire

摘要

As every horror fan knows, the secret of eternal youth is to suck the lifeblood of others. If you are a galaxy, that lifeblood is hydrogen gas, from which stars form. And it seems that some galaxies are indeed able to maintain a youthful appearance by sucking great clouds of the stuff in from intergalactic space. According to Felix Lockman of America's National Radio Astronomy Observatory, the Milky Way, humanity's home galaxy, is one such vampire. Dr Lockman is part of a team that has been using the Green Bank radio telescope in West Virginia, which boasts the world's largest steer-able dish, to study the process.