Question

How did observations with the Compton Gamma-ray Observatory show that gamma-ray bursts were not coming from the Milky Way Galaxy?

a) the bursts were all so “faint” (so little energy reached us) that they must be very far away

b) the gamma-rays were all Doppler shifted, showing the sources were moving very fast

c) the gamma-rays came from all over the sky, not just the plane of the Galaxy

d) the gamma-rays were seen mostly from the direction of the planets in our solar system

e) there were so few bursts observed with the Compton Observatory that it was not possible to figure out where they were coming from

Answer 1

Solution

A possible answer is,

C) The gamma ray came from all over from the sky, not just plane of the galaxy.

In the Compton gamma ray observatory there is this device called Burst and Transient Source Experiment(BATSE) which can search all over the sky(not just our milky way galactic plane). And the BATSE instrument averaged one gamma ray burst event detection per day for a total of approximately 2700 detections. It definitively showed that the majority of gamma-ray bursts must originate in distant galaxies, not nearby in our own Milky Way. Our milky way galaxy is almost contained in a plane such that if these gamma rays are coming from our own galaxy they should be concentrated on certain patch of the sky where the galaxy plane is crawling. Thus they must be coming from other galaxies too.

answered by: anonymous