Tuesday, August 26, 2008

GLAST...Oops, Fermi Releases First Light Image

NASA today officially renamed the Gamma Ray Large Area Space Telescope the Fermi Gamma Ray Space Telescope after Enrico Fermi (kind of surprising to me since Fermilab was already named after him). Fermi, as the name implies, looks at the universe in gamma rays rather than visible light. Gamma rays are the high energy photons that come from supernova remnants, pulsars, and matter falling into black holes, all that exotic, fun stuff.

The satellite was launched June 11th and has been undergoing it checkout since then. Today, they released the first light image.
This image shows the gamma ray intensity all over the sky. You can clearly see the plane of our galaxy and the center of our galaxy. Several well known strong sources are marked. You can also see a very dim (blue) diffuse background everywhere. One of the goals of the mission is to try and discover the source of this diffuse gamma ray background.

Another main goal is to find out what all the gamma ray sources are. NASA produced a neat poster a few years ago showing all the gamma ray sources and many of them were listed as "Unknown". Fermi has much better sensitivity and resolution so we can start figuring out what these things are.

Fermi also carries a Gamma Ray Burst Monitor. Gamma ray bursts are these really powerful explosions from the far reaches of the universe thar are caused by massive supernovas, black hole mergers, and cool stuff like that. It has been seeing about one a day so far. The increase in detection rate will help study these weird events as well.

I have worked on the Education program for GLAST since 2002 and had an invite to the launch (and couldn't make it due to another meeting). I did get to tour Spectrum Astro up in Phoenix in 2007 when they were building Fermi...got to don the whole bunny suit and go in the cleanroom (since they do DOD work, cameras were streng verboten so I have no pictures of that).

I am sure I will have an occasional blog on Fermi as time goes on and it releases major discoveries. I am just glad to see it up and working after being a small part of the team for the last six years!
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5 comments:

  1. MinnesotaChickAugust 26, 2008 at 10:53 PM

    Very cool! I always look forward to your posts.

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  2. AnonymousAugust 26, 2008 at 11:29 PM

    I think I saw the same program also. They described the gamma ray burst from a black holes and supernovas as a massive energy plume from the center of the event. The way they described the amount of energy released, it makes it seem that all the combined nuclear energy that we have harnessed on earth is equivalent to a grain of sand in the North African desert.

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  3. hale-boppAugust 27, 2008 at 11:05 AM

    I would have to do some math, logjam, but if anything, I suspect they are UNDERSTATING the energy in a gamma ray burst in that analogy (they definitely are not overstating it!) A gamma ray burst can release more energy in a couple of seconds than our Sun will in 10 billion years.

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  4. OrbsCorbsAugust 27, 2008 at 9:41 PM

    hale-bopp, how rewarding for you to work on things like this. I think it's great.

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  5. drewzepmeisterAugust 28, 2008 at 8:42 PM

    Hale,I'm not sure that I can understand all of this. It is interesting though:)

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