Posts Tagged ‘Glast’

Where’s That Antimatter Coming From?

Monday, November 3rd, 2008 by Bellatrix

One great mystery about our galaxy right now has to do with a cloud of antimatter near the center of the galaxy. No one knows exactly how or why this antimatter is being generated. However, data being looked at from the last four years, from the European Space Agency, may have had a bit of a break through.

Antimatter is the antiparticles to matter; where normal matter is made up of particles, antimatter is made of antiparticles. Each antiparticle has the same mass as its matter counterpart but is opposite in electric charge and magnetic properties, for example the antimatter partner to an electron is a positron. When matter and antimatter collide they annihilate releasing a large amount of energy.

This cloud of antimatter was discovered in the 1970’s. It is about 10,000 light years across and generates the energy of 10,000 suns. The cloud shines brightly with gamma rays; this is because of the antimatter colliding and annihilating with normal matter. Their interaction releases high-energy gamma rays, which allows for us to detect the antimatter’s presence. For years scientists have theorized the antimatter coming from radioactive elements produced in supernovae, or that the positrons are coming colliding stellar winds or other types of novae. But there was in evidence to really support any of these theories.

Now with data from the International Gamma-Ray Astrophysics Laboratory, or INTEGRAL, astronomers have noticed something new. The cloud extends further on the western side of the galactic center than on the eastern side. This location matches of very well with the distribution of a population of hard low-mass x-ray binary star systems. These star systems consist of a low mass star orbiting with either a neutron star or a black hole. X-rays are given off when gas from the low mass stars falls in on the neutron star or black hole. Because the positions of the binaries and antimatter line up so well astronomers believe that the binary systems are producing half or all of positrons seen in the cloud.

We now may have a good idea of where the antimatters coming from, however we still have no idea how/why exactly the binary systems are producing these positrons. Astronomers believe it has something to do with the jets of relativistic material and areas of strong magnetic fields that can be common with these types of systems. With the GLAST space telescope having been launched and starting to collect data, we could potentially gain a lot more insight into what exactly is going on very soon.

[Slashdot] [Digg] [Reddit] [] [Facebook] [Technorati] [Google] [StumbleUpon]

GLAST and The Mystery of Gamma Ray Bursts

Tuesday, August 26th, 2008 by Bellatrix

It has been nearly three months now since GLAST was launched, NASA’s Gamma-ray Large Area Telescope. The telescope isn’t fully functional right now, but according to NASA’s website the telescope is up and running and so far passing all of the checks the engineers are laying out.

Gamma rays are some of the most powerful and mysterious objects detected in space so far. As their name entails they are short-lived bursts of gamma ray photons, having energies ranging from a thousand electron volts to several billion electron volts. They range in duration from a few tenths of a second to a few minutes. However, this very short duration makes them very hard to detect and gather data on, since by the time a telescope is alerted to a burst and pointed in the right direction the burst will be over.

Gamma ray bursts are not well understood. They weren’t discovered until the 1960’s, and as late as the 1990’s astronomers weren’t even sure if these bursts were coming from the edge of the solar system or the edge of the universe. However, with recent advancement in technologies we’ve been discovering much more about them, giving us clues to their origin. We now know there are two different classifications of gamma ray bursts. Long Duration ones are bursts lasting 2 seconds to a few minutes, short duration ones are shorter than 30 seconds. Astronomers think fundamentally different processes create them. Long bursts are believed to be generated billions of light years away by the death or collapse of very massive stars, or Wolf Rayet stars. Short bursts are less understood, but may be created in very high energy collisions like between two neutron stars or a neutron star and black hole.

GLAST will be able to cover much more of the sky than the current gamma ray satellite, SWIFT. The GLAST team is currently in the process of checking the validity of the burst locations it detects. So far, GLAST has detected 12 bursts, and other telescopes have so far verified four of these bursts. Once all the checks have been performed and the team operations are running smoothly GLAST should start making some great discoveries. It will be able to gather data on a much higher number of bursts and tell us about the area from which they originated. Matching up the bursts with data about the originating area from before the bursts will hopefully tell us more about how they are created, such as if a known super giant star is in the vicinity of the bursts before but not after the burst.

New technology for this purpose is quite exciting. There are so many strange and mysterious things in the Universe we still don’t understand; to have something that may lead to a new discovery in astronomy is thrilling. It will be important to keep an eye on the data coming in once GLAST really gets going.

[Slashdot] [Digg] [Reddit] [] [Facebook] [Technorati] [Google] [StumbleUpon]

Our Undiscovered Universe Blog is proudly powered by WordPress
Entries (RSS) and Comments (RSS).