Seriously thoughtful WOW! 800 Trillion Suns at 7 billion light years away

[kennyc]

ScienceDaily (Oct. 14, 2010) — Astronomers using the South Pole Telescope report that they have discovered the most massive galaxy cluster yet seen at a distance of 7 billion light-years. The cluster (designated SPT-CL J0546-5345) weighs in at around 800 trillion Suns, and holds hundreds of galaxies.

"This galaxy cluster wins the heavyweight title. It's among the most massive clusters ever found at this distance," said Mark Brodwin, a Smithsonian astronomer at the Harvard-Smithsonian Center for Astrophysics. Brodwin is first author on the paper announcing the discovery, which appeared in the Astrophysical Journal.....


http://www.sciencedaily.com/releases...1013122559.htm

I thought this part interesting as well as the main discovery:

They're hunting for giant galaxy clusters using the Sunyaev-Zel'dovich effect -- a small distortion of the cosmic microwave background (a pervasive all-sky glow left over from the Big Bang). Such distortions are created as background radiation passes through a large galaxy cluster.

[Sparrow]

Originally Posted by kennyc

...discovered the most massive galaxy cluster yet seen...'
....among the most massive clusters ever found...

aren't those statements contradictory?

[HarryT]

I've corrected the thread title to read "800 trillion suns..." (it previously, and incorrectly, said "million" instead of "trillion").

[clarknova]

"WOW! 800 Trillion Suns at 7 billion light years away"

Well, at least there were... 7 billion years is a pretty long time ago.

[HarryT]

Originally Posted by clarknova

"WOW! 800 Trillion Suns at 7 billion light years away"

Well, at least there were... 7 billion years is a pretty long time ago.

Not a particularly long time in the lifetime of a galaxy. Our own Sun, for example, at about 5 billion years old, is only about half way through its lifetime as a main sequence star.

[clarknova]

Originally Posted by HarryT

Not a particularly long time in the lifetime of a galaxy. Our own Sun, for example, at about 5 billion years old, is only about half way through its lifetime as a main sequence star.

7 billion years is half the (believed) lifetime of the universe. I'd say that's pretty long. Who knows how many of those galaxies have drifted away, or collided, &c.?

[kennyc]

Originally Posted by HarryT

I've corrected the thread title to read "800 trillion suns..." (it previously, and incorrectly, said "million" instead of "trillion").

Thanks Harry. Typo's 'r me.

[kennyc]

Originally Posted by clarknova

7 billion years is half the (believed) lifetime of the universe. I'd say that's pretty long. Who knows how many of those galaxies have drifted away, or collided, &c.?

Exactly. One reason I found it so interesting...

[HarryT]

Originally Posted by clarknova

7 billion years is half the (believed) lifetime of the universe. I'd say that's pretty long. Who knows how many of those galaxies have drifted away, or collided, &c.?

I should perhaps say that cosmology was my field as a professional astronomer, before I discovered that IT was a lot better paid .

Galaxies are among the oldest things in the universe - pretty much all the galaxies we see today had formed within a billion years of the Big Bang; our own Milky Way galaxy appears to have formed within 100 million years of the BB (you can estimate the age of a galaxy by looking at the amount of beryllium in its globular clusters - it's an element whose abundance has increased pretty much linearly throughout the lifetime of the universe).

Galaxies don't really "die". They are gravitationally bound structures which "stick together" pretty much forever. They may cease star formation eventually (although none has yet done so), but the galaxy carries on, and its mass really doesn't change.

Hence my view that if this galaxy cluster contained 800 trillion solar mass' worth of material 7 billion years ago, it's still going to do so today.

[Falcao]

deleted.