A Milky Way Question

Dollan · Post #1by **Dollan** » 23.03.2005, 06:00

It's nine billion years ago. There is almost certainly a structure that could be called the Milky Way... but what would it look like? Had our Galaxy largely formed into a spiral this long ago, or was it still evolving towards that state? Was it smaller, not having "eaten" as many companion galaxies as it has by the present? Was star formation more rampant?

Thoughts? Definitive answers? Good guesses?

...john...

Evil Dr Ganymede · Post #2by **Evil Dr Ganymede** » 23.03.2005, 06:13

What does a galaxy nine billion lightyears away look like?

Seriously. I'm guessing our milky way would have looked like the distant galaxies we see today. Maybe even like a quasar, with a young, growing, voracious, massive black hole devouring huge quantities of leftover gas and dust and stars and being obscenely bright in the process.

Dollan · Post #3by **Dollan** » 23.03.2005, 06:18

You know, it's initial answers like that which make me realize that I never think these things through enough before I ask about them!

Okay, so I have a good idea, then. Not very hospitable for intelligent life, but the possibility probably can't be ruled out completely (with a hardy thanks to an optomistic email from Seth Shostak).

Thanks!

...john...

Evil Dr Ganymede · Post #4by **Evil Dr Ganymede** » 23.03.2005, 10:39

I dunno... if it's quasar-like (or even seyfert-like, as in an active core), the radiation from that might just frazzle any habitable world in the galaxy enough to prevent life from forming. Unless perhaps they're right on the rim...

And don't forget the lower average metallicity of the stars back then. Sure, you may get pockets where massive stars have exploded and enriched the local area with metals, but consider that the galaxy might not really have clusters of massive stars yet - it might not have formed into a spiral (with the star formation areas in the arms) yet.

Don. Edwards · Post #5by **Don. Edwards** » 23.03.2005, 23:08

Well from the most recent hubble phots that have been relesed the galaxies of that time had just as much structure as they do now. It seems to have been quite unexpected but they really did look pretty much as they do now. Now if you go back a few billion years further than I think you find that there strutures were less organised. If I can find the link to the story and photos I will post it.

Don. Edwards

Don. Edwards · Post #6by **Don. Edwards** » 23.03.2005, 23:18

Here or the links to the stories.

http://www.space.com/scienceastronomy/g ... 40119.html

http://www.space.com/scienceastronomy/g ... 40105.html

Don. Edwards

Dollan · Post #7by **Dollan** » 23.03.2005, 23:21

Thanks for the links, Don!

...John...