Radio Signal From Distant Galaxy
As part of their research into the formation of stars in distant galaxies, astronomers detect radio signals emitted by nearby galaxies. As they explain, the signals become weaker the farther the galaxy is from Earth, and it is difficult to catch them with current radio telescopes.
“A galaxy emits different kinds of radio signals. Until now, it’s only been possible to capture this particular signal from a galaxy nearby, limiting our knowledge to those galaxies closer to Earth,” says Arnab Chakraborty, a Post-Doctoral Researcher at McGill University under the supervision of Professor Matt Dobbs.
“A galaxy emits different kinds of radio signals. Until now, it’s only been possible to capture this particular signal from a galaxy nearby, limiting our knowledge to those galaxies closer to Earth,” says Arnab Chakraborty, a Post-Doctoral Researcher at McGill University under the supervision of Professor Matt Dobbs.
“But thanks to the help of a naturally occurring phenomenon called gravitational lensing, we can capture a faint signal from a record-breaking distance. This will help us understand the composition of galaxies at much greater distances from Earth,” he adds.
As researchers explain, the signal detected by the team was emitted from this galaxy when the universe was only 4.9 billion years old, enabling the researchers to glimpse into the secrets of the early universe. “It’s the equivalent to a look-back in time of 8.8 billion years,” says Chakraborty, who studies cosmology at McGill’s Department of Physics.
“Gravitational lensing magnifies the signal coming from a distant object to help us peer into the early universe. In this specific case, the signal is bent by the presence of another massive body, another galaxy, between the target and the observer. This effectively results in the magnification of the signal by a factor of 30, allowing the telescope to pick it up,” says co-author Nirupam Roy, an Associate Professor in the Department of Physics at the Indian Institute of Science.
These results demonstrate the feasibility of observing faraway galaxies in similar situations with gravitational lensing. According to researchers, it also opens opportunities for probing the cosmic evolution of stars and galaxies with existing low-frequency radio telescopes.