Clemson astronomers to study mysterious antimatter in the Milky Way

Feb 16, 2009

NASA has awarded Clemson astronomers $244,000 to use data from several space-based gamma-ray telescopes to study a mysterious emission coming from the central regions of the Milky Way galaxy.

Gamma rays, the light of energy a thousand times more powerful than X-rays, created by antimatter and normal matter coming together, are seen coming from the disk of our galaxy, roughly from where we see the glow of the Milky Way under a dark sky, but mostly from the direction of the center of the galaxy in the Southern hemisphere.

"We're not surprised to see this emission from the Milky Way's disk," said Mark Leising, Clemson University astronomy professor and principal investigator in the study. "We know that massive stars explode as supernovae there, fusing new elements from lighter ones. Such explosions long ago made the oxygen and iron in our blood and the calcium in our bones, along with most other heavy elements. Some of these elements are radioactive and produce antimatter positrons when they decay.

"What is surprising is how bright this emission is from the center of the galaxy," he said. "It is not coming just from the very center, where a black hole lurks that is two million times the Sun's mass, but from a region a few thousand light-years across surrounding the center."

Leising adds the supernova explosions do not occur there, so something else must be making the antimatter. One explanation, he said, involves black holes, collapsed stars of five to 10 solar masses, pulling matter from close companion stars. Another involves the decay of exotic "dark matter" particles. Dark matter is the name given to something out there that is so far detected only by its gravitational pull on normal matter.

In collaboration with colleagues from Germany, France and NASA's Goddard Space Flight Center, Leising and Clemson students hope to unravel this mystery by combining information from a number of NASA and European Space Agency satellites.

Leising said students have to study many topics in physics and become experts in computational and statistical techniques to do this type work. Leising also notes that such technical advances inevitably lead to spinoff benefits.

"Development of these detectors and analysis techniques aided in the development of PET (positron emission tomography) scanners, in which patients ingest radioactive elements that decay and emit antimatter. We are doing much the same thing, except that we have to sit back 25,000 light years to measure the gamma rays," he said.

Source: Clemson University

Explore further: Astronomer confirms a new "Super-Earth" planet

add to favorites email to friend print save as pdf

Related Stories

Physicists confirm existence of new type of meson

May 01, 2014

(Phys.org) —Physicists in the College of Arts and Sciences at Syracuse University have made several important discoveries regarding the basic structure of mesons—subatomic particles long thought to be ...

LHC celebrates five years of not destroying the world

Sep 12, 2013

Five years ago, at breakfast time, the world waited anxiously for news from CERN, the European Organization for Nuclear Research. The first nervy bunch of protons were due to be fired around the European ...

12 matter particles suffice in nature

Dec 13, 2012

How many matter particles exist in nature? Particle physicists have been dealing with this question for a long time. The 12 matter particles contained in the standard model of particle physics? Or are there ...

Recommended for you

Kepler proves it can still find planets

Dec 18, 2014

To paraphrase Mark Twain, the report of the Kepler spacecraft's death was greatly exaggerated. Despite a malfunction that ended its primary mission in May 2013, Kepler is still alive and working. The evidence ...

User comments : 3

Adjust slider to filter visible comments by rank

Display comments: newest first

frajo
1 / 5 (1) Feb 16, 2009
Anybody around to explain why these gamma rays necessarily have to be caused by matter-antimatter annihilation? Is there no known alternative mechanism which can produce this kind of radiation?
deatopmg
1 / 5 (1) Feb 17, 2009
It's certainly not at all clear if these antimatter gamma rays are 0.522 MeV or a little more. ??? This release is all fluff.

2 x 0.522 MeV being the (binding) energy released when and electron and positron "annihilate" sic each other (actually, return to a place where we can no longer detect them.)
yep
not rated yet Feb 18, 2009

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.