Astronomers have detected radio signals from a galaxy that have been travelling for 8.8 billion years, making it the most distant galaxy ever recorded at these wavelenghts. The detection was made using the Giant Metrewave Radio Telescope in India, which looked for the 21cm line, a wavelength emitted by hydrogen gas and a key observation when investigating how stars form in other galaxies.
“Until now, it’s only been possible to capture this particular signal from galaxies nearby, limiting our knowledge to those galaxies closer to Earth,” says Arnab Chakraborty from McGill University, who led the research.
Fortunately, nature lent a helping hand with a phenomenon called gravitational lensing, where a massive galaxy or cluster bends the light from a distant object, acting like a lens and magnifying the light. This allowed Chakraborty and his team to observe galaxy SDSSJ0826+5630, the light from which left it when the Universe was just 4.9 billion years old, offering a glimpse into the early Universe.
“This will help us understand the composition of galaxies at much greater distances from Earth,” says Chakraborty.