Have you ever wondered what the heart of a galaxy looks like? Or what is really going on in a super-massive black hole? Well now, an international team of astronomers led by our very own Dr Leah Morabito, has revealed the most detailed-ever radio images of galaxies at frequencies around the FM radio band.
The images have been created from data collected, over almost a decade, by the Low Frequency Array (LOFAR), a network of over 70,000 small antennae spread across nine European countries.
The LOFAR network captures images at FM radio frequencies which, unlike shorter wavelength sources like visible light, are not blocked by clouds of dust or gas, allowing astronomers to peer into star-forming regions and the hearts of galaxies themselves.
The majority of LOFAR antennae are located in the Netherlands and ordinarily only the signals from antennae in the Netherlands are combined to create a ‘virtual’ telescope with a collecting ‘lens’ diameter of 120km.
However, this time the team used the signals of all the European antennae, increasing the virtual lens diameter to almost 2,000km and giving a twenty-fold increase in image resolution. The result is images that reveal the inner-workings of nearby and distant galaxies.
The new images have focused on jets from super-massive black holes that are usually invisible to the naked eye but burn bright into radio waves.
The team’s work forms the basis of nine scientific studies that reveal new information on the inner structure of radio jets in a variety of different galaxies.
The project has been supported in the UK by the Science and Technology Facilities Council (STFC) and carried out in partnership with Manchester University in the UK, and partners in 8 European countries.
Image 1 - N. Ramírez-Olivencia et el. [radio]; NASA, ESA, the Hubble Heritage Team (STScI/AURA)-ESA/Hubble Collaboration and A. Evans (University of Virginia, Charlottesville/NRAO/Stony Brook University), edited by R. Cumming [optical]).
Image 2 - L.K. Morabito; LOFAR Surveys & DESI Legacy Imaging Surveys