About Topic In Short:

Who:

Astronomers from Montreal and India, Arnab Chakraborty and Nirupam Roy.

What:

Detecting radio signals emitted by distant galaxies through gravitational lensing, using the Giant Metrewave Radio Telescope in India.

How:

Gravitational lensing magnifies the signal coming from a distant object, enabling telescopes to pick up the signal. The process involves observing a distant star-forming galaxy known as SDSSJ0826+5630 which exists 8.8 billion light-years away.

Introduction:

The study of distant galaxies and the early universe has been a fascinating area of research for astronomers for many years. The ability to detect radio signals emitted by these galaxies can provide valuable information on the cosmic evolution of stars and galaxies. However, due to the weakening of these signals as they travel further away from Earth, it has been difficult for radio telescopes to pick up these signals. In this article, we will explore how the recent discovery of a radio signal from the most distant galaxy was made possible, and its implications for future astronomical research.

The Need for Radio Signals from Distant Galaxies

To understand the importance of detecting radio signals from distant galaxies, we first need to understand the limitations of current telescopes. Radio signals emitted by galaxies become weaker as they travel further away, making it challenging for telescopes to pick them up. However, these signals can provide valuable information on the gas content, atomic mass, and star formation of distant galaxies.

Gravitational Lensing

One solution to the problem of weak radio signals is gravitational lensing. Gravitational lensing occurs when the gravitational field of a massive object, such as a galaxy or a cluster of galaxies, bends the path of light from a more distant object. This bending can magnify the light, making it easier to detect by telescopes.

The Discovery of the Radio Signal from the Most Distant Galaxy

Astronomers from Montreal and India recently made a groundbreaking discovery using gravitational lensing. They were able to capture a faint radio signal from a galaxy known as SDSSJ0826+5630, which exists 8.8 billion light-years away. This distance indicates that the galaxy is closer to the Big Bang. The signal was detected using the Giant Metrewave Radio Telescope in India, and it was found to come from a star-forming galaxy. Scientists were also able to measure its gas composition and observe that the atomic mass of the gas content is almost twice the mass of the visible stars.

Implications for Future Research

The discovery of this radio signal from the most distant galaxy has significant implications for future astronomical research. It demonstrates that gravitational lensing can be used to observe distant galaxies under comparable circumstances, creating new possibilities for using low-frequency radio telescopes to study the cosmic evolution of stars and galaxies.

Thus Speak Authors/Experts:

According to Arnab Chakraborty, a Post-Doctoral Researcher at McGill University, "The signal detected 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." Nirupam Roy, an Associate Professor in the Department of Physics at the Indian Institute of Science, added, "Gravitational lensing magnifies the signal coming from a distant object to help us peer into the early universe. This effectively results in the magnification of the signal by a factor of 30, allowing the telescope to pick it up."

Conclusion:

The recent discovery of a radio signal from the most distant galaxy using gravitational lensing has opened up new possibilities for observing distant galaxies and studying the early universe. With the use of low-frequency radio telescopes and gravitational lensing, astronomers may be able to explore galaxies at much greater distances from Earth, providing valuable insights into the cosmic evolution of stars and galaxies.

Image Gallery

Illustration showing detection of the lensed 21 cm atomic hydrogen emission signal from a distant galaxy. Credit: Swadha Pardesi

Images of the atomic hydrogen signal, the detection spectrum and the lens. Credits: Left and middle panels: Chakraborty & Roy, GMRT/NCRA-TIFR Right panel: ESA/NASA HST and eHST/STScI/CADC.

Radio telescopes dishes at National Radio Astronomy Observatory -Giant Metrewave Radio Telescope. India, Pune, GMRT.

An exhibitor arranges a scaled down model of Giant Metrewave Radio Telescope (GMRT) (Photo by Manjunath Kiran / AFP) (Photo credit should read MANJUNATH KIRAN/AFP via Getty Images)