Understanding gamma-ray emission from nova explosions:
One of the first signals to emanate from a nova explosion is an intense burst of X- and gamma rays, long before the peak of the optical brightness is reached. At such a time, the 511 keV gamma-ray line is directly linked to the amount of radioactive 18F synthesized in the explosion. Thus, observing the 511 keV gamma ray intensity in a nova explosion would give astronomers a direct “thermometer” in the heart of the explosion. The problem is that the rates of nuclear reactions that create and destroy 18F in this environment are highly uncertain, including specifically the 18F(p,𝛼)15O and 18F(p,γ)19Ne reactions. Complementary to work on the 18F(p,𝛼)15O reaction performed at TUDA, DRAGON has measured a key resonance in 18F(p,γ)19Ne for the first time, finding it to be much weaker than previously thought, and reducing the uncertainties in the amount of 18F produced in these scenarios.