![]() These results demonstrate the feasibility of observing atomic gas from galaxies at cosmological distances in similar lensed systems with a modest amount of observing time. Roy explained, "In this specific case, the magnification of the signal was about a factor of 30, allowing us to see through the high redshift universe." ![]() This discovery was made possible by a phenomenon known as gravitational lensing, in which the light from the source is bent due to the presence of another massive body, such as an early type elliptical galaxy, between the target galaxy and the observer, essentially "magnifying" the signal. This discovery allows scientists to study the early universe and the formation of galaxies in a new way, and it will help to understand the evolution of neutral gas at different cosmological epochs. "Due to the immense distance to the galaxy, the 21 cm emission line had redshifted to 48 cm by the time the signal travelled from the source to the telescope," says Chakraborty. The signal was emitted from this galaxy when the universe was only 4.9 billion years old, making it the most distant signal of its kind ever detected. "Until now, the most distant galaxy detected using 21 cm emission was at redshift z=0.376, which corresponds to a look-back time - the time elapsed between detecting the signal and its original emission - of 4.1 billion years (Redshift represents the change in wavelength of the signal depending on the object's location and movement a greater value of z indicates a farther object)," it said.Īrnab Chakraborty, a post-doctoral researcher at the Department of Physics and Trottier Space Institute of McGill University, and Nirupam Roy, Associate Professor, the Department of Physics, IISc, were able to detect the signal from the galaxy which has a redshift of 1.29. However, this radio signal is incredibly weak, making it nearly impossible for present telescopes to detect the emission from a far-off galaxy. This brand-new discovery presents a once-in-a-lifetime chance to research the origins of galaxies and the early universe. These waves can be detected using low-frequency radio telescopes like GMRT (Giant Metrewave Radio Telescope). (National Centre for Radio Astrophysics)Īccording to report from PTI, 21 cm emission is a direct indicator of the atomic gas content in both nearby and far-off galaxies because atomic hydrogen emits radio waves of that wavelength. View Full Image The Giant Metrewave Radio Telescope, located in Pune, India, received the record-breaking signal.
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