These foreground objects are so huge that they warp spacetime in their vicinity, creating something of a cosmic funhouse-mirror that can both multiply and magnify the background objects. Gravitational lenses are formed when massive objects, such as galaxy clusters, are positioned in front of more distant background objects from our line-of-sight on Earth. “Strong gravitational lensing phenomenon can significantly amplify the faint signal, enabling us to detect the signal from galaxies at higher redshifts in a reasonable observation time,” the team added. “The strong gravitational lens, nature’s gift, magnifies the weak emission signal coming from distant objects, enabling us to peer through the high-redshift universe,” said Chakraborty and his co-author, Nirupam Roy of the Indian Institute of Science, in the study. The team detected the signal in the galaxy, called SDSSJ0826+5630, thanks to the amplification provided by the warped spacetime effects of the gravitational lens. Now, a pair of scientists led by Arnab Chakraborty, a post-doctoral research fellow at McGill University, used the Giant Metrewave Radio Telescope in India to spot “the highest redshift detection in emission from an individual galaxy to date,” according to a new study published in Monthly Notices of the Royal Astronomical Society. However, the radio signals emitted by neutral hydrogen are very faint, which means that it is only possible to see them at low “redshifts,” which is a measurement that constrains the age and distance of astronomical objects. These atoms are the fuel that feeds star formation in galaxies, making them an important window into the evolution of stars and galaxies.

The array is an international effort to build the world's largest radio telescope that's expected to be completed within the next decade.The 21-centimeter line, also known as the hydrogen line, is named after the 21-centimeter wavelengths emitted by neutral hydrogen atoms in deep space. Murphy said more powerful telescopes, such as the planned Square Kilometer Array, may help solve the mystery. 'Luckily, the signal returned, but we found that the behavior of the source was dramatically different - the source disappeared in a single day, even though it had lasted for weeks in our previous ASKAP observations.' Because the signal was intermittent, we observed it for 15 minutes every few weeks, hoping that we would see it again,' Murphy said in the statement. 'We then tried the more sensitive MeerKAT radio telescope in South Africa. However, the Parkes telescope failed to detect the source. Follow-up observations were conducted with the Parkes radio telescope in New South Wales and South African Radio Astronomy Observatory's MeerKAT telescope.

The object was initially spotted during a survey of the sky using the Australian Square Kilometer Array Pathfinder radio telescope, known as ASKAP, which has 36 dishes that work together as one telescope at the Murchison Radio-astronomy Observatory in Western Australia. This behavior was extraordinary,' said study coauthor Tara Murphy, a professor at the Sydney Institute for Astronomy and the School of Physics at The University of Sydney, in the release. 'This object was unique in that it started out invisible, became bright, faded away and then reappeared. The fickle object has been named after its coordinates in the night sky: ASKAP J173608.2-321635. The signals from this new source of radio waves, however, don't match what astronomers expect from these types of stars. The team initially thought it could be a pulsar - a very dense type of rapidly spinning neutron (dead) star, or a type of star that emits huge solar flares. This means its light oscillates in only one direction, but that direction rotates with time,' he said in a news release. 'The strangest property of this new signal is that it has a very high polarization.

The brightness of the object varies dramatically, and the signal switches on and off apparently at random, said Ziteng Wang, lead author of the new study in The Astrophysical Journal and a doctoral student in the School of Physics at The University of Sydney. The energy signal is unlike any phenomenon studied before and could suggest a previously unknown stellar object, according to a new study.

2004 radio signal from space