New gammaray space telescope's first picture

[Martin]

http://www.washingtonpost.com/wp-dyn/content/article/2008/08/26/AR2008082603101.html

 

During its first 95 hours of operation the new instrument produced a map of the gammary sky.

 

When they launched it, the name was GLAST for gammaray large array space telescope. Now that it is in operation it has been renamed Fermi, after the physicist Enrico Fermi.

 

Here is a Scientific American article about it:

http://www.sciam.com/article.cfm?id=glast-telescope-first-light

 

Here's the NASA website for the Fermi Space Telescope

http://www.nasa.gov/mission_pages/GLAST/main/index.html

 

Things to notice are that while the Hubble Space Telescope was designed to see in optical wavelengths----photons around 1 or 2 electron volts---

the Fermi instrument sees in wavelengths which are a billion times shorter----photons with energies a billion times greater.

These energetic photons would not make it down thru the atmosphere (thankfully) because they would interact with the air. So the only place to study the gammaray sky is up in orbit.

 

There are these socalled hypernovas that produce great flashes of gammaray energy called Gammary Bursts (GRB), of several kinds. And it is not clear what the mechanism that produces GRB is. There is more energy in a GRB than in a supernova explosion. So they want to use Fermi to study these things. Maybe they occur when a massive star collapses to a black hole. (a type of supernova is caused by collapse to neutron star----collapse all the way to a black hole would presumably be more extreme).

 

There are other questions that Fermi telescope can help address. There are some versions of quantum gravity which (if true) would lead to slight variations in the speed of highly energetic photons----so these QG theories would be shot down if Fermi doesn't find variation in photon speed with energy. So Fermi could help test (and possibly falsify) some versions of QG. Any kind of empirical input like that would provide helpful guidance to QG theorists. There has been quite a lot of talk about GLAST (now Fermi) in the QG community. They have reason to be excited that it's finally up and running.

Edited August 30, 2008 by Martin