Local Hot Bubble in X-Ray Background Confirmed

Scientists say that a study of origin of the soft X-ray glow that blankets whole of the sky has made them find clues about one of the many mysteries of our universe.

One group of scientists proposes that origin of the X-ray emissions is outside our solar system and in the local hot bubble which is a region of hot gases. Whereas the second hypothesis says that the X-ray emissions are from inside the solar system and when the solar wind from the sun collides with the diffused gases, such emissions are generated.

A recent study which was led by Massimiliano Galeazzi of the University of Miami reveals that both the hypotheses are correct to some extent. According to this study, most of the X-ray emission is from the local hot bubble that has gas at 1 million degrees whereas less than 40% of the emissions are from within the solar system.

The findings have been published in the journal Nature.

"Specifically, the existence or non-existence of the local bubble affects our understanding of the galaxy in proximity to the sun and can be used as foundation for future models of the galaxy structure", said Galeazzi.

The scientists had launched a research rocket in the year 2012 into the upper region of atmosphere in order to analyse the X-ray background. They were basically focussing on low-energy X-rays. The rocket reached an altitude of 258 kilometres and was placed above the Earth's atmosphere for five minutes. In that time gap, the instruments of the rocket collected all the necessary data and then transmitted it to the unit on the ground.

The hot bubble may have been formed when a supernova emitted a lot of material into the interstellar medium which formed a cavity there. Another supernova occurred later inside the cavitythat filled it with extremely hot gases which emit X-rays.