|
|
The Question
(Submitted November 10, 1996)
I am an Italian girl and I'm eleven years old. I should like to know the
principle sources known of the X-rays and Gamma-rays in the Universe.
Thank you very much .
The Answer
Thank you for you interest. It is impressive that someone so
young is interested in these topics. There are many types of sources that
produce X-rays, gamma-rays or both. Two types of objects, "active galactic
nuclei" (which include quasars), and "X-ray binaries" produce
X-rays and to a lesser extent, gamma-rays. Active galactic nuclei are most
likely powered by supermassive black holes (as massive as millions to billions of
suns). Some X-ray binaries may also contain black holes. Supernova explosions
also produce a lot of X- and gamma radiation. There is hot gas in some
galaxies, including our Milky Way, that produces X-rays. Stars, including our
Sun, produce X-rays, particularly in their coronae. There is also a mysterious
phenomenon called "gamma-ray bursts" which are now being detected
daily by
the Compton Gamma-Ray Observatory. Scientists are not sure yet what these
are, but they are very energetic. For more information on these topics, try
looking at the Learning Center Web pages.
Have fun,
Andy Ptak and the Ask a High-Energy Astronomer team
|
