Among the dishes of the Giant Metrewave Radio Telescope (GMRT) near Pune, Maharashtra, India. Credit: National Centre for Radio Astrophysics
Probing galaxies at much higher distances from Earth might now be within reach.
How do stars form in far-off galaxies? Astronomers have actually long been attempting to answer this question by identifying radio signals given off by close-by galaxies. However, these signals end up being weaker the further away a galaxy is from Earth, making it challenging for present radio telescopes to select up.
Now researchers from Montreal and India have actually recorded a radio signal from the most far-off galaxy up until now at a specific wavelength referred to as the 21 cm line, enabling astronomers to peer into the secrets of the early universe. With the assistance of the Giant Metrewave Radio Telescope in India, this is the first time this kind of radio signal has been identified at such a big distance.
Illustration showing detection of the signal from a remote galaxy. Credit: Swadha Pardesi
” A galaxy discharges various type of radio signals. Previously, its just been possible to record this particular signal from a galaxy close by, restricting our understanding to those galaxies closer to Earth,” states Arnab Chakraborty, a Post-Doctoral Researcher at McGill University under the supervision of Professor Matt Dobbs.
” But thanks to the help of a naturally happening phenomenon called gravitational lensing, we can catch a faint signal from a record-breaking distance. This will assist us comprehend the structure of galaxies at much higher ranges from Earth,” he adds.
An appearance back in time to the early universe
For the first time, the scientists were able to spot the signal from a distant star-forming galaxy called SDSSJ0826 +5630 and measure its gas composition. The scientists observed the atomic mass of the gas material of this specific galaxy is practically two times the mass of the stars visible to us.
Image of the radio signal from the galaxy. Credit: Chakraborty & & Roy/NCRA-TIFR/GMRT
The signal found by the group was produced from this galaxy when the universe was just 4.9 billion years old, enabling the researchers to peek into the tricks of the early universe. “Its the equivalent to a look-back in time of 8.8 billion years,” states Chakraborty, who studies cosmology at McGills Department of Physics.
Selecting up the signal from a distant galaxy
” Gravitational lensing magnifies the signal originating from a distant item to assist us peer into the early universe. In this specific case, the signal is bent by the presence of another enormous body, another galaxy, between the observer and the target. This efficiently results in the magnification of the signal by an aspect of 30, enabling the telescope to pick it up,” states co-author Nirupam Roy, an Associate Professor in the Department of Physics at the Indian Institute of Science.
According to the researchers, these results demonstrate the expediency of observing faraway galaxies in similar circumstances with gravitational lensing. It likewise opens exciting brand-new opportunities for probing the cosmic evolution of stars and galaxies with existing low-frequency radio telescopes.
Referral: “Detection of H I 21 cm emission from a highly lensed galaxy at z ∼ 1.3″ by Arnab Chakraborty and Nirupam Roy, 23 December 2022, Monthly Notices of the Royal Astronomical Society.DOI: 10.1093/ mnras/stac3696.
The Giant Metrewave Radio Telescope was developed and is operated by NCRA-TIFR. The research was funded by McGill University and the Indian Institute of Science.
How do stars form in distant galaxies? Astronomers have actually long been trying to address this question by identifying radio signals given off by close-by galaxies. These signals become weaker the additional away a galaxy is from Earth, making it challenging for present radio telescopes to pick up.
” Gravitational lensing amplifies the signal coming from a distant object to help us peer into the early universe. In this particular case, the signal is bent by the presence of another massive body, another galaxy, between the observer and the target.