Scientists may have gotten a better look at the cosmic rays being produced in the center of our galaxy after discovering a source that is accelerating galactic cosmic rays to unprecedented energy with the help of the H.E.S.S. observatory.
Earth is bombarded by high energy particles that usually originate from sources beyond our planet in space. These particles are often known as cosmic rays and can be electrically charged, which is why the interstellar magnetic fields that pervade our galaxy often reflect them. This means that the particles' paths are often randomized due to the deflections. This makes it difficult to find out exactly where they come from in the first place.
With that said, cosmic rays interact with both light and gas in the neighborhood of their sources. This, in turn, produces gamma rays. Because these rays travel in straight lines, undeflected by magnetic fields, they can therefore be traced back to their origin.
In theory, cosmic rays with energies up to one petaelectronvolt (PeV)2 should be produced in our galaxy. Until now, though, researchers have only found cosmic rays with energies up to about 100 tetraelectronvolts (TeV1) until now.
In this latest study, the researchers used detailed observations of the galactic center region made by H.E.S.S. to find out a bit more about cosmic rays. During the first three years of observations, H.E.S.S. uncovered a powerful source of gamma rays from giant molecular clouds that surround the galactic center in a region about 500 light-years across.
Deeper observations showed a bit more about the processes powering the cosmic rays. For the first time with the measurements, the researchers were able to pinpoint the source of the particles: somewhere within the central 33 light-years of the Milky Way, there's a cosmic source that accelerates protons to energies of about one petaelectronvolt continuously.
But what is this object? Currently, researchers aren't sure. However, it's possible that it could be a supermassive black hole.
The results reveal a bit more about our galaxy as well as cosmic rays. This, in turn, may lead to new discoveries about the Milky Way.
The findings were published in the March 16 issue of the journal Nature.
