In one of the first astrophysical studies of the period when the first stars and galaxies formed, researchers have been able to make some key determinations.
Using data from India's SARAS3 radio telescope, researchers led by the University of Cambridge were able to look at the very early universe and place limits on the mass and energy output of the first stars.
The researchers were able to place these limits on the earliest galaxies because they didn't find the signal they were looking for.
The researchers were able to rule out scenarios such as inefficient heaters of cosmic gas and efficient producers of radio emissions because of the non- detection.
An important step in understanding how our universe transitioned from mostly empty to one full of stars can be found in the results of the study.
The goal of new observatories is to understand the early universe. The results obtained using the SARAS3 data are a proof-of-concept study that paves the way to understand the development of the universe.
The SKA project will likely be able to make images of the early universe, but it will be difficult for current telescopes to detect the first stars re-radiated by hydrogen clouds.
The 21-centimeter line is a radio signal that was created in the early universe. Unlike the recently launched JWST, which will be able to directly image individual galaxies in the early universe, studies of the 21-centimeter line, made with radio telescopes such as the Cambridge-ledREACH, can tell us about entire populations of even earlier. The first results are expected early in the 20th century.
Astronomers look for a radio signal produced by hydrogen atoms in the early universe to detect the 21-centimeter line. The researchers developed a way to see through the fog of the early universe and detect light from the first stars. In the current study, some of these techniques have been used.
A research group operating the EDGES experiment published a result that seemed to hint at the earliest light. It was reported that the signal was strong compared to what is expected. The EDGES result is still pending confirmation from independent observations.
The Cambridge-led team did not find a signal in the re-analysis of the data. The team was able to limit the properties of the first stars.
Data from the SARAS3 experiment was used by the Cambridge team to look for signals from the beginning of the universe. Researchers were unable to find a signal in the data.
The paper's lead author is a PhD student from Cambridge's Cavendish Laboratory. We can limit its depth if we don't find that signal. That informs us about how bright the first stars were.
The hydrogen signal can be used to estimate the population of first stars and galaxies. Limits on some of the key properties of the first sources of light include the mass of the earliest galaxies and the efficiency with which they can form stars. How efficient these sources are in emitting X-ray, radio and ultraviolet radiation is addressed.
"This is an early step for us in what we hope will be a decade of discoveries about how the universe transitioned from darkness and emptiness to the complex realm of stars, galaxies and other heavenly objects we can see from Earth today," said Dr.
The first of its kind, the observational study excludes scenarios in which the earliest galaxies were more than a thousand times brighter than the present ones in their radio-band emission.
The first stars and galaxies could have had a measurable contribution to the background radiation that appeared as a result of the Bigbang and which has been traveling towards us ever since.
It's amazing to be able to look back in time and see the beginning of the universe.
Astrophysical constraints from the SARAS 3 non-detection of the Cosmic dawn sky averaged 21- cm signal, Nature Astronomy.
Journal information: Nature Astronomy
All Rights Reserved © 2024
