#gama rays

"WHITE DWARF MERGERS COULD BE SOURCE OF OUR GALAXY'S EXOTIC GAMMA-RAYS"

 In a new paper written by Roland M. Crocker of the Australian National University and colleagues, the mystery to the first gamma-ray emission coming from outside the solar system may have been finally solved. Through this paper, the scientists examined the possibility that white dwarfs merging could be the source of antimatter and these emissions.  The first gamma-ray emissions detected beyond our solar system were observed over forty years ago today. These signals are often associated with the destruction of positrons - a type of antimatter - through their devastating interaction with normal electrons. However, for years scientists haven't been able to find a source of these antimatter particles in our galaxy - at least until now.  In the paper, the researchers pointed out that if two white dwarfs (which are remnant cores of sun-like stars after they ran out of fuel) circled each other in a binary system, they could interact with each other through a phenomenon called mass transfer. By exchanging gases with each other, these two white dwarfs could eventually merge and this merger could result in the creation of radioactive isotopes that decay into positrons.

A source accelerating Galactic cosmic rays to unprecedented energy discovered at the centre of the Milky Way

March 16, 2016 The H.E.S.S. measurement of the gamma-ray emission can be used to infer the spectrum of the protons that have been accelerated by the central black hole—revealing that Sgr A* is very likely accelerating protons to PeV energies. Currently, these protons cannot account for the total flux of cosmic rays detected at the Earth. "If, however, our central black hole was more active in the past," the scientists argue, "then it could indeed be responsible for the bulk of the galactic cosmic rays that are observed today at the Earth." If true, this would dramatically influence the century old debate concerning the origin of these enigmatic particles. Read more at: http://phys.org/news/2016-03-source-galactic-cosmic-rays-unprecedented.html#jCp 

There are few frequencies of electromagnetic radiation we haven’t exploited, and some have their dangers…

Radio waves, microwaves, gamma rays… all these waves are made of the same ‘stuff’ – oscillating electric and magnetic fields moving at the speed of light. But that doesn’t mean they’re all alike. The various types of electromagneticwaves have different properties that are determined by their…