Record-Breaking Galaxy Found In Deep Hubble Image 196
The Bad Astronomer writes "Astronomers using Hubble Space Telescope have found a galaxy at the very edge of the Universe: the light from this far-flung object has been traveling a whopping 13.1 billion years to get here! The galaxy appears as a non-descript dot in the infrared Hubble Ultra Deep Field taken using the Wide Field Camera 3, but a spectrum taken using a ground-based telescope confirms that we're seeing this object as it was a mere 600 million years after the Big Bang itself."
Does it still exist? (Score:5, Interesting)
Record breaking (Score:3, Interesting)
I am not sure it is a record-breaking galaxy, but Hubble is definitely a record-breaking telescope!
Re:Does it still exist? (Score:2, Interesting)
I think there's a maximum length after which a galaxy cannot exist; diminishing element returns from supernovae. Unfortunately I'm not sure how long it is, but it's much longer than 13 billion years; individual red dwarves can last for hundreds of billions of years. As for merger with other galaxies or destruction by a supermassive black hole though, its anyone's guess.
If the universe is under 15 billions years old, how do we know red dwarves can last 100 billion years?
Re:Does it still exist? (Score:3, Interesting)
What if that blob of a gallaxy is is really the Milkyway when it was very young and the light we are seeing has in fact traveled around the curve of the Universe so we can see it now the way it was then.
We only have to wait 13.1 billion years to see if it evolves into what we see locally now.
How fast was that galaxy moving? (Score:2, Interesting)
So they're trying to tell me that within 600 million years of the big bang, that galaxy managed to get 13 billion light years away from where our galaxy now lies? Even if we and it are at opposite ends of the universe, it would have to have gotten 6.5 billion light years from the center of the universe in those 600 million years, yes? It sounds like it must have been going a bit over the speed limit, don't you think? It got that far away, and still had time to form into a galaxy? Why is my slide rule melting as I try to figure out how it got so far away so quickly? Maybe the light took 13 billion years to reach us, but it's been going around in circles? If so, that Galaxy might be a LOT closer, as the crow flies.
Re:How does this work? (Score:2, Interesting)
Re:Does it still exist? (Score:3, Interesting)
The Universe is really good about recycling stuff. From what we know of the preservation of mass/energy and the evolution of galaxies and stars, the stuff that galaxy was made of was is still there mostly - except for tiny fraction of mass that's been converted to energy - a small fraction of which is the light that we see. The stars have gone Nova or Supernova, faded to red giants, or collided with other stars to be reignited and reborn as a new class of star while throwing off much mass that cools to become dust or wayward planets. The Galaxy core has swallowed much, as have the thousands of black holes that live within that galaxy, and those black holes have evaporated much back out, most of the mass would still be free from any black hole and would exist as stellar systems composed of stars orbited by planets, comets, asteroids and dust. Between the stars will be bits of dust and gas as usual, but mostly vast cold empty space. Given the standard distribution it's likely that galaxy has had several collisions with neighboring galaxies, with considerable mixing, and flung some of its stuff into the cold dark abyss but gained much more in the merger. It may have settled into a standard galactic form, or be involved with a messy galactic collision as our galaxy is. Still it's likely that there are stars there, as much as here and in as good variety, with worlds and comets circling the stars, and moons about the worlds. Life is no more likely to arise here than there. There are doubtless many millions of stars in that galaxy that humans would find habitable yet. Without data we have no reason to believe or disbelieve that in that mass of stars there is not now life looking back at the mass of stars our predecessor galaxy was those billions of years ago, wondering if there is intelligent life here or if there might be someday.
"There" is somewhat of a tricky term since it's a good bit further away now than it was when the light that we see left there. Across such distances "now" has a rather fluid meaning as well - what time it is there depends somewhat on the path you take to get there and even at the speed of light the straightest path isn't necessarily the shortest. Also, "is" is a bit of a struggle. The universe has expanded so much in that time that the light that leaves here now cannot fall upon the stuff those stars were made of, ever. And if that stuff has escaped our light cone, can it be said to still "be"?
And yet if we look in the opposite direction we can see galaxies nearly as far away as this - and someday we may beat this range in that direction. We can be sure these galaxies on the distant edge of vision from here and diametrically opposed have never seen each other and never will: there was no time for that light to get from the one to the other before the expansion of the Universe flung them so far apart that they have always existed in separate light cones. In the imaginary experiment where in a static reference frame we could transport instantaneously to the stuff these distant galaxies have become there is no reason to believe that the view from there is any different than from here: stars and galaxies, as far as our current telescopes can see both back toward us, and the other way also. For certain if we could jump that distance twice and looked back, we would see the other side of this same galaxy, as each sun shed its light in all directions.
If we could repeat that jump over and over some think we might end up where we started, as the curvature of space itself bends back in some way until if you go far enough, you come home. Among these some think that in this distant galaxy the Universe is so tightly curved that we're already looking at our galaxy from the other side, somewhere out there in the sky. Others that more leaps are required.
Some thinkers take the divergent view that that the Universe is flat - or curves the other way, and eventually instead we would come to the End, whereafter is nothing but light flung into the dark neve
Re:How fast was that galaxy moving? (Score:3, Interesting)
Good question! I think it has something to do with the stretching of space-time. The galaxy was there 600 million years after the big bang, 13 billion light years from where we were going to be, but space-time (the universe) was smaller. In a way, the light-year was smaller than it is now, but that galaxy was still moving away from our location at nearly light speed.
What is interesting to me is that a galaxy could be formed at all in 600 million years!
Re:Does it still exist? (Score:3, Interesting)
Sorry, but it took a really long time to compose my response to the parent. Please refer below.
Also: if the curvature of space is recursive and uniform in all directions, and we can see ourselves from here, then the microwave background pattern of the Universe is not an echo from the Big Bang. That signal must then be ourselves at whatever distance the curvature loops back, and the pattern is doppled by the masses along the loop which gives us a way to map all that is.
Re:Does it still exist? (Score:3, Interesting)
The discipline that applies into everything, but in itself is about nothing (real).
It's kind of like C++ in that regard. It can do anything, but without the appropriate libraries (application knowledge) it can do nothing.
Re:How fast was that galaxy moving? (Score:1, Interesting)
What's really going to blow your mind is that the observable universe is 90ish billion lys across. Space is expanding, and the expansion is accelerating. That makes it so there exists a distance where the space expanding between us and what we're trying to see moves us away at faster than lightspeed, thus, the light will never reach us. Look up the term "comoving distance".
Also: http://www.scientificamerican.com/article.cfm?id=misconceptions-about-the-2005-03&page=5
Enjoy.
Can a galaxy form in such a short period of time? (Score:3, Interesting)
So can a galaxy be created in 600 million years?
AGE vs SIZE of the unverse (Score:3, Interesting)
I am surprised to see so many comments without even one mentioning the difference between the AGE of the Universe (13.7 billion l.y. ) and the SIZE of the observable universe (radius 47 billion l.y.).
http://en.wikipedia.org/wiki/Observable_universe [wikipedia.org]
From the Wiki Article:
The age of the Universe is estimated to be 13.7 billion years. While it is commonly understood that nothing travels faster than light, it is a common misconception that the radius of the observable universe must therefore amount to only 13.7 billion light-years. This reasoning makes sense only if the Universe is the flat spacetime of special relativity; in the real Universe, spacetime is highly curved on cosmological scales, which means that 3-space (which is roughly flat) is expanding, as evidenced by Hubble's law. Distances obtained as the speed of light multiplied by a cosmological time interval have no direct physical significance.[11]
So, the light from this Galaxy actually traveled more than 13.7 billion years (I don't know how to make the conversion but probably around 45 billion ?)
XARG.
Re:Space is a big place.... (Score:1, Interesting)
Here is my question. According to the most current theories I have read, at some point after the big bang, the universe underwent a period of faster than light inflation. Which apparently is possible due to the fact that nothing was actually moving faster than light, just new space was being created between objects making them move apart at ftl speeds. Does this kind of narrow down the timeframe of when that happened? If this galaxy was moving ftl, how could we see it? At the very least, would not the light from it have redshifted to extreme frequencies due to its relative velocity? Or is the ftl expansion the reason that this is the oldest galaxy we have seen? Maybe before 13.1 billion years ago, everything was expanding at ftl rates, and the light will never reach us. Or would the light emitted catch back up once the rate of expansion slowed back to sub-light? If that is the case, could we even tell if the age of the emitted light was greater than the distance of the galaxy that emitted it, thus proving the ftl expansion theory? Forgive me if none of this makes sense. I never went to college and I work at a gas station.
Re:How fast was that galaxy moving? (Score:2, Interesting)
One parsec is 3.262 light years
13.1 billion light years = 3980 Mpc
Apparently, Hubbles constant places the rate of expansion at 77 (km/s) / Mpc:
77 (km/s) / Mpc * 3980 Mpc = 306460 km/s
So, this galaxy is moving away from us roughly at the speed of light. I guess that means time will appear to stand still when we observe that galaxy?
Re:How fast was that galaxy moving? (Score:1, Interesting)
Astrophysicist here. Just to clarify, we will never know whether this galaxy exists at a point where in it's own reference frame the age of the Universe is 13.7 Gyrs. This is because this galaxy is out of our event horizon now, i.e., if we shone a light beam towards that galaxy today, then that light beam will never reach that galaxy. (This is true for all objects with redshift >~ 2 in the currently favored cosmological model.)
We can see the light from the galaxy today because the light was emitted in the distant past and the rate of expansion was slower then. Hence the distinction between observable Universe and causally connected. This galaxy is observable but not causally connected to our Galaxy (and vice-versa).
Re:twinkle twinkle little photon (Score:3, Interesting)
hubble has a 2.4 m2 reflector. estimate the galaxy at 4x10E37 watts, with 2.5e18 photons per watt, and you get about 1200 photons per second. there are a LOT of stars in a galaxy.