stars first then then galaxies? I don't think so.

greatergood · Post by **greatergood** » Thu Mar 23, 2006 4:41 pm

This image says that stars formed before galaxies. Not to be a fly in the ointment, but...

From my understanding, the Tidal Torque Theory says that dark matter collapsed into "dark halos" all within the first 400 million years, and they provide the gravitational forces behind galaxy formation and angular momentum (spin). Doesn't that then mean that galaxies formed before stars?

Furthermore, all numerical methods that support TTT only work if the matter that makes up the stars is very smoothly distributed in the galaxy system during the galaxy formation. In other words, the stars form out of this matter after the final size and spin of the galaxy is mostly established.

BMAONE23 · Post by **BMAONE23** » Thu Mar 23, 2006 5:44 pm

I would think that they tended to form simultaneously (or nearly given what time really is). The galactic mass would need to be there prior to its forming stars. Much like new stars form today. The gas (mass) needs to be there before it can gravitationally collapse into new stars, and form visible galaxies.

But what about the dark galaxies? They would have mass but no visible light (yet??).

greatergood · Post by **greatergood** » Thu Mar 23, 2006 8:36 pm

Perhaps you're right, but all the computer simulations in galaxy formation fail unless most all of the matter is in a non-clumpy state. I'm guessing there are a few, very very few stars that exist and form during that process, and according to the simulations they are so few that it's hardly worth mentioning.

The wording on today's image (http://antwrp.gsfc.nasa.gov/apod/ap060323.html) gives the impression that the general rule is that stars formed before galaxies, whereas the mathematical models indicate just the opposite for 99% of the stars in the universe.[/url]

greatergood · Post by **greatergood** » Thu Mar 23, 2006 8:41 pm

It is also extremely non-linear. There should be a X-axis for time that states "logarithmic". Actually, an inverse exponential scale for the diagram is even a better fit since so much happens in the first second of the big bang.

harry · Post by **harry** » Fri Mar 24, 2006 8:21 am

The question is can stars form without galaxies?

Yes

Can galaxies form without stars

No.

Which came first?

neither. In this case its the chicken and the egg.

If the universe is infinite in time and space. Than what we actually have is a process of endless recycling.

No start no end.

Have a look at this link:

http://www.spaceandmotion.com/cosmology ... -space.htm

I'm not saying that i fully agree with it, but! it does have some good points.

Recycling occurs,in many ways

1) Stars exploding and stars reforming from the matter fallout.

2) Jets from stars, ejecting matter and used again.

3) Ultra dense plasma, that holds back all forms of radiation from excaping, which we call Black Holes. Create huge jets that expell so much matter that they can reform the galaxy. See M87 link

http://www.aao.gov.au/images/captions/aat053.html
http://www.physics.usyd.edu.au/rcfta/an ... ode10.html

http://www.space.com/scienceastronomy/a ... 11030.html

4) and many more ways

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