Did you know that you live in a bubble? Actually, we all do. Our solar system is surrounded by a bubble of hot gas that spans roughly 300 light years. It was first detected in the 1970s by scientists who measured x-rays coming from the gas, but what produces these x-rays has remained a mystery for over 40 years. Some scientists believed that the x-rays came from the exchange of electrons between the solar wind (particles emitted from the sun) and the gas of the bubble, while others believed they originated from the leftover radiation of exploding stars called supernovas.
Comprised of physicists and engineers from around the world, the Diffuse X-rays from the Local galaxy, or DXL, mission is led by the University of Miami’s physicist Dr. Massimiliano Galeazzi and works to discover what causes the emission of x-rays from the bubble. The first DXL mission launched in 2014 and consisted of a satellite being launched 160 miles from the surface of earth for approximately five minutes. That’s all the time DXL needed to collect data and conclude that only 40 percent of the x-rays detected were from charge exchange between the solar wind and gas. The other 60 percent was determined to have been radiation from supernovas in our galaxy’s distant past.
According to Dr. Galeazzi, the results from the DLX mission “affects our understanding of the area of the galaxy close to the sun, and can, therefore, be used as a foundation for future models of the galaxy structure.”
Dr. Galeazzi and DXL launched another mission in January of this year to confirm their previous results and collect new data for further research on the bubble.
“A lot of effort has been put into disentangling the various contributions to this signal” said Lucky Puspitarini, an astrophysicist at the Observatoire de Paris in Paris, France. “Finally, the results are converging! This ends a long-standing controversy.” Thank you, to our own shining star, Dr. G., whose research has shed light on this fascinating interstellar phenomenon!