By Chuck Woodbury
I suddenly feel smaller. A lot smaller. A new “sky map” as measured by a low frequency radio telescope has revealed 300,000 previously unknown galaxies.
Our Earth, of course, is located in but one galaxy. From what I am told, it’s not a very big one.
A mission to Mars, something I can hardly wait to witness, now seems to me like a walk next door to the 7-Eleven.
An international team of more than 200 astronomers from 18 countries has published the first phase of a major new radio sky survey using the Low Frequency Array (LOFAR) telescope. The survey reveals hundreds of thousands of previously undetected galaxies, shedding new light on many research areas including the physics of black holes and how clusters of galaxies evolve.
A special issue of the scientific journal Astronomy & Astrophysics is dedicated to the first twenty-six research papers describing the survey and its first results.
Radio astronomy reveals processes in the Universe that we cannot see with optical instruments. In this first part of the sky survey, LOFAR observed a quarter of the northern hemisphere at low radio frequencies. At this point, approximately ten percent of that data is now made public. It maps three hundred thousand sources, almost all of which are galaxies in the distant Universe; their radio signals have traveled billions of light years before reaching Earth.
“Magnetic fields pervade the cosmos, and we want to understand how this happened,” explained Shane O’Sullivan at the University of Hamburg. “Measuring magnetic fields in intergalactic space can be difficult, because they are very weak. However, the unprecedented accuracy of the LOFAR measurements has allowed us to measure the effect of cosmic magnetic fields on radio waves from a giant radio galaxy that is 11 million light years in size.”