Hydrogen is an essential building block of the universe. Whether stripped down to its charged core or packaged into a molecule, the nature of its existence can tell you a lot about the characteristics of the universe at the largest scales.
Because of this, astronomers are very interested in detecting signals from these elements, wherever they may be found.
Now the effect of light on uncharged hydrogen atoms has been measured further from Earth than before, by some margin. The Giant Metrewave Radio Telescope (GMRT) in India caught the signal by extension review time – The time between the flash of light and its detection – is 8.8 billion years.
This gives us a glimpse into some of the first moments in the universe, which are currently estimated to be around 13.8 billion years old.
“A galaxy emits different types of radio signals,” says cosmologist Arnab Chakrabortyfrom McGill University in Canada. “Until now, it was only possible to pick up on this particular signal from a nearby galaxy, which limited our knowledge of the galaxies closest to Earth.”
In this case, the radio signal emitted by the hydrogen atom is a light wave with a length of 21 cm. Longwave is not very active, and the light is not very strong, so it is difficult to detect from a distance; that Past record review time It is only 4.4 billion years old.
Due to the large distance before being intercepted by the GMRT, the 21 cm beam line was extended by expanding space to 48 cm, a phenomenon described as red shift from light.
The team used gravitational lensing to detect the signal, which originates from a distant star-forming galaxy called SDSSJ0826+5630. Gravitational lensing is where light is magnified as it follows curved space around a massive object that lies between our telescopes and the original source, effectively acting as a lens. big.
“In this particular case, the signal was deflected by the presence of another massive object, another galaxy, between the target and observer.” said astrophysicist Nirupam RoyFrom Indian Institute of Science.
“This effectively magnifies the signal by a factor of 30, allowing the telescope to pick up on it.”
The results of this study will give astronomers hope that they will be able to make other similar observations in the near future: previously forbidden distances and return times now make sense. If the stars align, that is.
Hydrogen atoms are formed when hot ionized gas from the outskirts of the galaxy begins to fall into the galaxy, cooling along the way. Finally, it turned into a hydrogen molecule, and then into a star.
Being able to look back this far can teach us more about how our galaxy originally formed, as well as point astronomers toward a better understanding of how the universe behaved when it was very young.
The latest findings “will open up new and exciting possibilities for investigating the cosmic evolution of neutral gases using current and future low-frequency radio telescopes in the near future,” the researchers wrote in their paper. published papers.
Research published in Monthly Notices of the Royal Astronomical Society.
