A Major Signal From 'The First Stars' May Not Have Come From Space at All

A new study has found that the first light illuminating the Universe may not have come from the far reaches of the Universe. It may not be from space at all.

This new finding may set the Universe to rights, which is far from being a problem. The signal had some unexpected features that were hard to explain under current astrophysics.

If the signal was not light from the first stars, we don't need to invent new astrophysics to explain it.

The spectrum of the radio sky was measured with a radiometer, which shows that the profile found by Bowman et al.

The profile found by Bowman et al. is not evidence for new astrophysics or non-standard cosmology, according to our non-detection.

The Cosmic dawn is an important period in the history of the Universe. It covers a period from 50 million to a billion years after the Big bang. Before stars came along, our Universe was filled with a hot murky fog of ionized gas. Light could not travel through the fog because it scattered off free electrons.

After the Universe cooled down, protons and electrons recombine into neutral hydrogen atoms. Light could travel through space. The neutral hydrogen in the Universe was reionized by the ultraviolet light of the first stars and galaxies.

The universe was reionized by 1 billion years after the Big bang, but we can't really see with our current experiments, which makes the reionization process difficult to understand. It would be a game-changer if we could detect light from the dawn.

The EDGES experiment was looking for a signal in low radio frequencies and got a hit, but the signal was not what they expected. The hydrogen gas the light had passed through was colder than we thought, and the amplitude was almost twice as large as had been predicted.

The research team concluded that the only thing that could have cooled the gas to that degree was dark matter.

Singh and his colleagues used the Shaped Antenna Measurement of the Background Radio Spectrum 3 (SARAS 3) radiometer to see if they could confirm the signal.

In early 2020, they floated SARAS 3 out into the middle of remote lakes in Southern India and probed the sky for the signal detected by EDGES.

Singh's team found no signal to be found once the data had been processed and analyzed. The instrument did not duplicate the distortion of the radio spectrum seen in the data.

The MCMC analysis of the sky spectrum made with the SARAS 3 instrument did not detect the profile found by Bowman et al., they wrote in their paper.

The correlation analysis shows that the distortion present in the spectrum made using the EDGES low-band instrument, which was used to derive the best-fitting profile and define the bounds on the parameters for the profile, is not present in the SARAS 3 spectrum. The facts show that the sky spectrum made with the EDGES low-band instrument has a systematic error associated with it.

Singh and his team believe that the signal was an error produced by the EDGES antenna, not a signal from deep into the far reaches of space-time. The signal was ruled out by the sensitivity of the data. It was very bad.

The evidence needs to be extraordinary when something strange is discovered. To be certain of the signal's existence and what it is, more observations with different instruments should be done.

Singh and his team concluded that continued observations with sensors deployed in such environs, such as the SARAS 3 monocone on large water bodies in remote locales on Earth or a space mission in orbit on the lunar farside, would.

The results have been published.