Gamma-Rays

Page
2

CGRO uses compton scattering and pair production.

Launched in April 5th, 1991 on Atlantis shuttle. Had a visual range of 30 KeV to 30 GeV

Burst And Transient Source Experiment (BATSE), the Oriented Scintillation Spectrometer Experiment (OSSE), the Imaging Compton Telescope (COMPTEL), and the Energetic Gamma Ray Experiment Telescope (EGRET). http://cossc.gsfc.nasa.gov/

Returned to Earth on June 4th 2000.

Gamma-ray Large Area Space Telescope is being sent up by Nasa in 2007.

Slide 7

Gamma Ray Bursters

Does what it says on the box.

http://imagers.gsfc.nasa.gov/ems/gamma.html

The most energetic things in the universe that we know of.

More energy in 10 seconds than our sun can produce in its entire liftime of 10,000,000,000 years!

Slide 8

Glast

Gamma-Ray Large Area Space Telescope Large Area Telescope

Funded Jointly by the US, Japan, France and Sweden

Accuracy of 30 Arc seconds

Launch in 2006

Slide 9

CGRO

Compton Gamma Ray Observatory

Four telescopes on it:

1. BATSE

Base and Transient Source Experiment

2. OSSE

Oriented Scintilliation Spectrometer Experiment

3. COMPTEL

Imaging Compton Telescope

4. EGRET

Energetic Gamma Ray Experiment Telescope

Slide 10

CGRO egret

The Compton Gamma Ray Observatory Energetic Gamma Ray Experiment Telescope

80° Field of View

Launched in 1991 as an Experimental Program

Re-entered in 2004

Slide 11

Major EGRET Discoveries

The finding of a new class of objects--high energy gamma-ray emitting blazars, or grazars

The emission of high energy gamma-rays from a gamma ray burst for over an hour, with some gamma rays having energies over a GeV and two having energies over 10 GeV.

The observation of an increased fraction of pulsar electromagnetic radiation going into gamma rays as the age of the pulsar increases to a million years

The determination with high certainty that cosmic rays are galactic

The detailed mapping of the galactic diffuse radiation and the measurement of the pion bump in the high energy gamma-ray spectrum

The absence of microsecond bursts and its implication for certain unification theories

The long trapping time of over ten hours for energetic solar particles following a flare

A measurement of the diffuse, presumably extragalactic, high energy gamma ray spectrum

http://lheawww.gsfc.nasa.gov/docs/gamcosray/EGRET/highlights.html

Slide 12