Urgent help with "accretion of stars and galaxies" (1 Viewer)

[noobonastick]

Hi i have a dot point on the syllabus that i need help with, the text book doesnt explain it very well . Thanks =]

4. outline how the accretion of galaxies and stars occurred through:
a) expansion and cooling of the Universe
b) subsequent loss of particle kinetic energy
d) lumpiness of the gas cloud that then allows gravitational collapse

 

[Aerath]

In short:
Accretion is the process of growth of a body by gravitational attraction of more matter.

After a few hundred thousand years after the Big Bang, the Universe was cooled down and atoms were formed. As the Unvierse was further expanding and cooling, the atom particles lost kinetic energy and gravity began to attract them together forming regions of high mass density. The regions of high mass density began to attract nearby material and gain mass. This process is known as accretion.

At some time or another, all matter in the universe formed discrete gas clouds known as protogalaxies. As further accretion occured, galaxies were formed. Accretion also occured inside galaxies, forming stars.

That should get you started, but if you need a more detailed explanation, I'll type one up later on tonight.

 

[Dr. Zoidberg]

Try http://caresa.com.au/