Supernova Secrets Seen In X-Rays 23
wjcofkc writes "CNN reports that astronomers using NASA's NuSTAR telescope have for the first time mapped deep within the radioactive material from a supernova. The light from the originating star, Cassiopeia A, located about 11,000 light-years away and having had about eight time the mass of our sun, first reached Earth about 350 years ago. But that does not mean there still isn't a lot to study. Scientists using the NuSTAR, which stands for Nuclear Spectroscopic Telescope Array, launched in June 2012 and consisting of an instrument with two telescopes that focus high energy X-ray light, were able to peer deep within the cataclysmic aftermath. While there is currently no model for how the process of a supernova works, the findings in the study are a big step forward. 'Until we had NuSTAR, we couldn't see down to the core of the explosion,' Brian Grefenstette, lead author and research scientist at the California Institute of Technology, said at a news conference Wednesday."
No model eh? (Score:2, Informative)
http://en.wikipedia.org/wiki/Supernova#Current_models
http://arxiv.org/find/all/1/all:+AND+modelling+supernova/0/1/0/all/0/1
Slashdot editing at it's finest.
Re:Wilhelm Roentgen Would be Proud (Score:5, Informative)
Unfortunately, in this case the observed photons were actually low-energy gamma rays. I guess they are called "x-rays" in the article because they fall into the region of the electromagnetic spectrum that is usually associated with x-rays. Ti-44 undergoes electron capture to Sc-44, which emits the two gamma rays at 78 and 68 keV, and then the Sc-44 decays (again by electron capture) to Ca-44.
But they are not true x-rays.
Re:Wilhelm Roentgen Would be Proud (Score:5, Informative)
No it is not incorrect. Your definition comes from nuclear physics but X-rays and gamma rays can and are produced in other ways too. Electrons can just as well emit gamma rays, for example in inverse Compton scattering processes. And gamma rays are produced in inelastic proton scatterings. As you say, in astrophysics we classify based on energy and typically keV photons are X-rays and MeV photons and up are gamma rays.