The hot air balloon experiment recorded a mysterious radio signal that appears to be coming from outside the Milky Way. Astronomers do not yet have a precise explanation for this signal, but they say it may come from the stars of the first generation of the universe
The noise was detected by ARCADE equipment mounted on a hot air balloon that flew for four hours at 37 kilometers over Texas in July 2006. The instrument displayed a donut-shaped area that covered 7% of the sky.
A group of scientists was looking for small deviations in the spectrum of microwave background radiation - the first radiation that spread after the big bang.
Instead, after the known radio sources in the Milky Way and other galaxies were thrown away, radio interference remained that could not be explained, they filled the sky and were almost six times louder than all known astronomical sources combined, and were located at the same radio frequency.
The signal source is unknown. There is a possibility that this is the last gasp of the first stars in the universe, stellar giants that were hundreds of times more massive than the Sun and died within the first billion years after the Big Bang. When their cores disappeared into black holes, the stars probably emitted streams of charged particles that produced radio emission. This radiation can cause an unexplained signal.
In 2005, another group of scientists made a similar statement about determining infrared radiation from early stars. Astronomers say the infrared light that Spitzer was unable to trace to individual stars or galaxies may have been diffuse glow from the first stars in the universe. However, other scientists have argued that it was coming from nearby galaxies too faint for Spitzer to see.
Another possibility is that the mysterious radio signal could be created by distant galaxies, whose supermassive black holes accelerate charged particles to high speeds, producing radio emission.
High accuracy
This signal has not yet been noticed due to the fact that ground-based telescopes do not have the accuracy to determine it. To see this radio signal, ARCADE needed nearly 2,000 liters of liquid helium to cool its sensors and instruments, to maintain temperatures around -270 ° C. Creating such conditions on Earth would require insulating the telescope inside a vacuum chamber. This will reduce the accuracy of the observations by placing a barrier between the telescope and the radiation it needs to detect.