The Milky Way Galaxy is relatively typical of galaxies today, if a bit on the beefy side. It has about 200 billion stars, and is 100,000 light years across.
Now imagine a galaxy with that same mass, but only 5000 light years across. That would be an incredibly densely packed galaxy, and in all honesty, pretty freaky.
But that’s exactly what astronomers using Hubble and Keck have found! Probing the early Universe, 11 billion light years away, they found nine galaxies that are as massive as galaxies today, but far more compact. The galaxies are very young, only a half to one billion years old, judging from the types of stars they contain. Not only that, they appear to be quiet: unlike our galaxy today, these distant compact galaxies are not actively forming stars. It’s as if they formed all their stars all at once right from the start, and then that was that.
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| This plot shows that these galaxies really are small and massive. Size is shown on the vertical scale (bigger galaxies are near the top) and mass along the horizontal (more massive galaxies to the right). A big massive galaxy would be to the upper right, and a low mass, dinky galaxy to the lower left. These oddballs are marked, and are clearly separate from other galaxies: they are massive, yet small. |
That’s really weird! What could cause such galaxies to form so tightly jammed with stars? One idea is that in the early Universe there were pockets of dark matter, places where it was somewhat denser than on average. Hydrogen would have collected there, attracted by the fierce gravity, and formed the galaxies. Constrained by the dark matter pockets, the galaxies would have been very dense and formed stars furiously for a short period until all the hydrogen was used up. That would explain their small stature, dense stellar population, and lack of ongoing star formation. But it’s just a hypothesis for now.
What’s also odd is that we do not see any galaxies like these today; any galaxy of comparable mass that we see in the current Universe today is far larger, like our Milky Way. So these galaxies existed in the past — possibly in large numbers — but we don’t see them now. Where did they go?
They may get bigger with time. It’s not clear how they would do that, but perhaps the more massive stars fall to the center, flinging lighter stars outward, puffing up the galaxies over time (I describe this process a bit in a post yesterday about globular clusters). Maybe they collide and puff up — though that means they would get even more massive than we see them, and they’re already as hefty as galaxies today. Maybe they grow dark over time, and we just don’t see them any more.
Actually, I don’t like any of these answers very much. We obviously need a lot more observations of these tiny dense suckers. However, we’re pretty much at the limit now; it took Hubble’s and Keck’s incredible resolution to be able to see these things at all. We’ll have to wait for the Hubble servicing mission in September to get even deeper images, when the new Wide Field Camera goes online. I suspect that STIS, the spectrograph that I used to work on, may be able to help as well, if the astronauts can fix it too.
Either way, it’s cool to know the Universe can still throw us the odd curveball or two. The more we look, the more weirdness we find.
April 29th, 2008 at 10:01 am
What if the concentrated pocket of dark matter that was present during the birth of these galaxies evaporates or disipates requiring the galaxy to spread out to conserve angular momentum?
April 29th, 2008 at 10:17 am
Well heck, if it’s wierdness you want, we certainly don’t have to look around in the universe to find it! We’ve got some pretty dense people here on earth that are a significantly wierder than those galaxies
April 29th, 2008 at 10:21 am
How could they be really young if they’re 11 Billion light years away. Wouldn’t the light have taken 11 Billion light years to get from there to here. Which means we’re looking back in time at baby photos of really old galaxies, formed at a time when things were closer together in the universe?
April 29th, 2008 at 10:23 am
How could they be really young if they’re 11 Billion light years away. Wouldn’t the light have taken 11 Billion years to get from there to here. Which means we’re looking back in time at baby photos of really old galaxies, formed at a time when things were closer together in the universe?
Edit: added a correction.
April 29th, 2008 at 10:39 am
Of course you’re right. It’s just common parlance among astronomers to say that those galaxies “are” young.
April 29th, 2008 at 10:39 am
Exactly riki. We are seeing them when they are very young. We have no idea what these galaxies are like present day. What the question is is that if there were many galaxies this massive and this dense so long ago, where are they now? Or what are they now?
Does dark matter shift? I thought it was constrained by gravity as well, which would mean if it all clumped together so long ago to draw all the hydrogen in, there wouldn’t be any force strong enough to draw it out again.
Maybe since these galaxies are so massive and formed so quickly, they formed super massive, short lived stars that then exploded violently. Could this have thrown matter and energy outward if it happened enough to increase the size of these galaxies? Or maybe these galaxies ended up burning out and clumping even more to where they are just giant super massive black holes with smaller stars surrounding it. Or maybe even these galaxies collided with other smaller galaxies so that the original dense galaxy became the dense center of a very large galaxy, and the stars it picked up surrounded it into a normal spiral galaxy shape. Although these would be very large galaxies indeed.
April 29th, 2008 at 10:42 am
How does one measure the mass of a galaxy 11 billion light years away? I can see measuring the mass of a star based on how fast things orbit it, but can you really measure the orbital speeds of stars from this distance?
To riki:
Yes, these may be “baby photos”, but it’s all we have. We have no way of knowing what those galaxies look like today, or if they even still exist. Perhaps “the galaxies, as we see them, are very young” might be more precise? However, I think most people here at least know that the present tense applies to our view of an object, not how that object exists today.
April 29th, 2008 at 10:59 am
Question: when galaxies collide, do they lose mass? Are stars ejected from both galaxies during collisions?
If the answers are yes, then could that explain what happened to these dense galaxies? Collisions would have “puffed them up” but also expelled some stars, so the total mass wouldn’t increase.
April 29th, 2008 at 11:04 am
This is hilarious. Difficult to read b/c of the COLOR, but funny, if you feel the need to point and laugh at cooks.
http://www.lhup.edu/~dsimanek/solar.htm
April 29th, 2008 at 11:35 am
Maybe they collapsed and formed the supermassive black holes at the center of more “adult” galaxies…
April 29th, 2008 at 11:42 am
How come these galaxies aren’t also highlit?
(In case I can’t post images here: http://img301.imageshack.us/img301/5637/galaxieska5.png )
April 29th, 2008 at 11:57 am
Is it possible that we are seeing a small part of those galaxies?
effective radius is the radius at the half of the light, but what if those galaxies are more extended?
anyway, at these radius the galaxies are very dense…
definitely we need more deep observations…
April 29th, 2008 at 12:05 pm
dpa:
Be sure to follow the “additional information” link at the bottom of the page.
Besides, why would you want to laugh at cooks? Without cooks, how would we eat? We’d all starve!
April 29th, 2008 at 1:06 pm
The complexity and strangeness of the universe is amazing. As are the desire and ability of human beings to understand it.
Some human beings anyhow. Woo-woos and creationists are so fond of saying “Scientists don’t know everything.” Which is quite true. But unlike them, scientists are always trying to learn more. And succeeding.
April 29th, 2008 at 1:26 pm
They may get bigger with time. It’s not clear how they would do that,
A diet high in fat?
Without cooks, how would we eat? We’d all starve!
Despite being a male engineer, I’m an excellent cook, and- oh crap!
[QD vanishes]
April 29th, 2008 at 1:42 pm
If the stars in the young dense galaxies are close enough that they interact directly with each other through gravity (as opposed to interacting predominantly with the galactic centre), I can imagine the galaxy acting as a compressed gas that wants to expand.
April 29th, 2008 at 1:51 pm
Call my psychic hotline now so I can predict many minds attacking this mystery with vim, vigor and thesis papers!
Old, dense and far away. We’re seeing what they once were. One thing that you have to consider is “what are they NOW”.
That wasn’t for you old coots who do this for a living.
April 29th, 2008 at 1:51 pm
wintermute: Because those are part of the “local” sample that is being compared against to show how weird these particular galaxies are. In other words, there are two unhighlighted local galaxies that compact out of several hundred thousand in the sample, but *all* 9 galaxies that they observed at high redshift are that compact.
Actually, the explanation I like is that there’s a radial age gradient. In other words, the stars in the inner parts of the galaxy are, on average, younger (because gas tends to fall into the center, so you can form stars in the center for longer). Younger stellar populations are brighter than older ones, so the center is brighter than you’d naively expect and the inferred concentration of the galaxy is higher. As they say, that’s actually predicted by galaxy formation models, and they could test it by getting colour information – younger stellar populations are also bluer, so if the center of these galaxies is significantly bluer than the outer parts, that would be a smoking gun (or conversely, if the centers aren’t any bluer, than that would rule out this explanation).
[TMB]
April 29th, 2008 at 2:39 pm
Nice Animal House reference, BA.
My theory (which is mine): these galaxies formed early, quickly evolved life -> intelligence -> technological civilizations, one of which invariably invented a Star Trek TOS-style planet killer that got loose and ate all the stars.
April 29th, 2008 at 2:43 pm
Oh, I know! Goddidit!
What!? What do you mean “that’s not an explanation”!?!
April 29th, 2008 at 2:57 pm
If Halton Arp is correct, these are nearby compact low mass galaxies
Problem solved.
April 29th, 2008 at 3:22 pm
Gustav,
Actually, if it were God, then they would have been perfect little galaxies all along, but this is a sign that the alien ID’s are, in fact, real and getting better at creating galaxies without all the waste.
April 29th, 2008 at 3:35 pm
Isn’t dark energy the new, trendy repulsive force that unbinds the universe? If no one else has pulled a dark energy explanation out of thin air, let me be the first. Umm, I’ll get to the math later.
April 29th, 2008 at 3:53 pm
aha. Modern astronomy does not describe it perfectly. That means that it most all be wrong and we have to stop teaching it in schools. Time and time again it is proven the answer to anything we don’t know “because god created it that way” is the only one that works all the time. Much like when I tell my son “because I said so”. This would save us lots of money because much of schooling is eliminated.
Fortunately China, India, and other countries could provide us with doctors, scientist, and engineers as they foolishly waste their money on things like science education. Our tax dollars can be spent on other things.
April 29th, 2008 at 4:02 pm
Hmmm. This seems to go along with some alternative cosmology (and no, I don’t mean the wahoo “goddidit” or “we’re in The Matrix” kinds) I’ve been editing for a friend which actually predicts this sort of thing. I wonder if we’ll see more of them.
April 29th, 2008 at 9:13 pm
Now’s that strange… How the sky would look in those galaxies?
April 29th, 2008 at 9:49 pm
Great post. Very interesting (as usual). And bonus points for the National Lampoon’s Animal House reference in the title!
April 30th, 2008 at 3:40 am
Can someone pls help me with an answer.
The universe is compared to the surface of balloon with the dots on it referred to as galaxies. On the surface of the balloon one wouldn’t be able to see to dots which are on the other side of the curvature of the balloon. But how come we detect galaxies at are 11 to 13 billion light years away. Doesn’t the curvature of the universe appear even at such mind bending distances? Or do we see these galaxies at the other side by looking inside the balloon?
April 30th, 2008 at 10:12 am
Deepak: In that analogy, space is the surface of the balloon, so light travels along the surface of the balloon. You would be able to see the galaxies on the other side because of light rays that travel along the (curved) surface of the balloon.
However, the evidence is that the global curvature of space is actually zero, so the correct 2d analogy is that we’re on the surface of an expanding infinite flat sheet. People like the balloon analogy because it’s easier to picture a balloon expanding than an infinite sheet expanding.
April 30th, 2008 at 12:28 pm
Another way to look at it is that these are objects about the same sizes as the Milky Way’s central bulge, but 10x more massive….
April 30th, 2008 at 12:31 pm
Fer -
Funny you should ask. Follow the link from the BA’s posting, click on “Release Images”, and you’ll see a rendition of what the night sky might look like.
April 30th, 2008 at 3:46 pm
Superstring
“If Halton Arp is correct, these are nearby compact low mass galaxies
Problem solved.”
Sounds conceivable, but I suspect Halton Arp might have a different interpretation. They don’t have the Blazar appearance of Quasars. They appear to be huge elliptical galaxies maybe 10 billion years of age or much older because of their inactivity and non-spiral form. Only one, possibly two from our perspective, appears to have a spiral form. If we were seeing primarily the central core areas of such galaxies and if they were four times further away than we currently believe, then they would be very large but normal everyday galaxies.
The BB paradigm has asserted that this 11 billion years ago is very close to the “dark ages where fully formed galaxies should not exist, especially condensed ones.
I predict we are looking at the beginning of the end of the BB theory, because in the future, accordingly, we will see ever increasing quantities of these galaxies and no other types at these distances. Accordingly BS interpretations will necessarily abound — until one day in the not too distant future the light will go on for some astronomers and contrary theories will begin.
you heard it first here.
your friend forrest
May 1st, 2008 at 12:05 pm
Ken B
“How does one measure the mass of a galaxy 11 billion light years away? I can see measuring the mass of a star based on how fast things orbit it, but can you really measure the orbital speeds of stars from this distance?”
You’re right Ken, they make an assumption that because of their relative brightness per unit volume at that distance they must have a lot of stars densely packed with them.
As to the age of the stars they make the same assumption. Although they really can’t pinpoint individual stars, groups of stars appear to be bright relative to their size so they conclude that they’re young. Of course the BB paradigm would not allow them to have any other age at that distance.
Spaceman Spiff
“Another way to look at it is that these are objects about the same sizes as the Milky Way’s central bulge, but 10x more massive…”
You pretty much have it nailed , I think, excepting for the 10 times more dense which I believe is just an observational misinterpretation of the data.
This is directly related to another observation this month of finding
“many old galaxies” 10 billion light years away. Implying that the BB perspective of the formation of the universe is failing in its predictive ability. Where are the predictions related to these findings. The answers can be found only in a number of alternative cosmologies.
http://www.spaceref.com/news/viewpr.html?pid=25098
your friend forrest
May 5th, 2008 at 5:53 pm
@ forrest:
BB “failing in its predictive ability” would have been impressive if it had, but as you can see from the article it hasn’t. And you can also see from the cluster post that it has weathered real predictive failure (galaxies seemingly older than the universe).
May 6th, 2008 at 12:04 am
Torbjörn,
The implications here are that by the observations of the nine galaxies above as well as the URL that I posted, I believe, you are seeing the beginning of the end of the BB theory. There will be countless similar future observations having continuously greater red-shifts, with astronomers asserting continuously denser galaxies and galaxy clusters. First they will claim they are seeing the dark ages, then they will see past it. All of these observations will be misinterpreted. Below you will find one of the Predictions of over 70, that you will be continuously seeing.
The age of the observable universe is much older than has been asserted using the Big Bang model(s). Continually higher red-shifted galaxies will be found until the Big Bang model will necessarily break down at about 35 Billion light years which is more than twice its present estimated age of 13.7 Billion years — probably much sooner as a result of multiple inadequacies of the BB model – but probably not completely until a viable alternative theory is available. Many of these galaxies will have the same quantities of metal within them as comparable middle-age galaxies would have that are relatively close to us including our own. This would be evidence that 13 Billion years or more in the past, middle aged galaxies existed which would be completely contrary to the BB model.
The Pan Theory perspective is that the observable universe is probably not expanding. Instead consider the observable Universe as constant in size but the matter within it as getting smaller. New matter would be continuously created from the lost material (dark matter) which would maintain a constant density. Each time frame of the observable universe would have the same matter saturation as any other observable time frame. This is what really differentiates the Pan Theory from an expansionist theory like the BB.
Sit back and watch these prediction come true or you can be sent upon your request, 70 current predictions of this theory. Many of these predictions are over 30 years old and are all under copyrights. The Title of the theory is the Pan Theory. The title of the technical papers, soon to be book form is The Pan Theory, a General Unified Model of cosmology, the forces of physics, classical mechanics, and quantum theory.
For additional info/ predictions or text gratis– forrest_forrest@netzero.net
Misinterpretations will last, let’s say eight more years, with many alternative BB theories being offered before the BB as well as several other major theories in physics today will go down in flames. You heard it first right here on the BA blog.
your friend forrest
May 6th, 2008 at 4:31 pm
@ forrest:
This is not a prediction that can be drawn from consistent observations. As I noted earlier BB theory (which isn’t predicted on such observations, btw) has weathered inconsistent observations which tells us it is a robust theory. And accordingly BB theory was recently verified, IIRC beyond reasonable doubt for the first time, by WMAP 5 year data.
Your age claims are obviously erroneous, check the science, so I fail to see why you make them.
May 6th, 2008 at 5:26 pm
Hi Torbjörn,
You’re right at the present time. But this is a prediction that can be drawn from consistent observations, we just haven’t seen enough of these observations yet, but we will. The Big Bang has no well-know future predictions except for one, that the universe is 13.7 Billion years old or younger. Google search future predictions of the Big Bang. All you will ever find is observations that claim a prior prediction. Just try to find one and let me know, I haven’t. Every new observation is a surprise to BB theorists, like the one above. Doesn’t that say something in and of itself.
Wouldn’t a theory that has made many past and future predictions which are being continuously observed, and which is a much simpler explanation of observed reality, be better?
You will soon find out, I believe, that these age predictions that I have given are only conservative.
WMAP 5 data cannot account for the radiation of hydrogen in the Milky Way as explained by Verschuur and his radio astronomy observations.
No correlation is needed, only that WMAP 5 would observe such hydrogen which has never been denied to my knowledge.
http://www.dsri.dk/~mykal/tmp/tycho/Verschuur.doc
If you want more info/ predictions — I’ll send you them free for your consideration or critique. They are part of an entire book related to this subject that will be published first in English in the fall of 2010.
forrest_forrest@netzero.net
May 13th, 2008 at 7:43 am
@ forrest:
May 14th, 2008 at 3:17 pm
Torbjörn, I agree, put up or shut up. Presentation is in order. I’ll be looking forward to your e-mail requesting additional information.
My related 250 page copyrighted book of new theory is entitled, The Pan Theory, a General Unified Model of cosmology: unifying the forces of physics, classical mechanics, and quantum theory. — “Everything that you ever wanted to know, and maybe a few things that you didn’t. The most pondered questions of all times are answered in simple language and logic.” (English publication scheduled for the fall of 2010) Currently partially translated into 12 languages.
These are three of the 70+ listed and “observable”, copyrighted predictions which I thought may be most relevant to the observations above, and as I asserted, evidence for an older universe . Additional evidence for the Predictions below, along with extended text and related equations, is available to all upon request, see e-mail address below. (it’s too long to present here)
1. The age of the observable universe is much older than has been asserted using the Big Bang model(s). Continually higher red-shifted galaxies will be discovered until the Big Bang model will necessarily break down at about 35 Billion light years of age which is more than twice its present estimated age of 13.7 Billion years — probably much sooner as a result of the multiple inadequacies of the BB model – but probably not until viable alternative theory(s) becomes well-known. Many of these galaxies will have the same quantities of metal and chemistry within them as comparable middle-age galaxies would have that are relatively close to us including our own. This would be evidence that 13 Billion years or more in the past, middle aged galaxies existed which would be completely contrary to the BB model. (discussions and evidence, pages 43- 44B, 84-89)
3. Everything at a distance (distant galaxies) will be perceived as being larger, more luminescent, moving faster, accelerating more, being greater distances apart, and having wider spectrums than it really displayed in its own time (copyrighting by the Pan theory in 1983) —hence the asserted (but unreal) accelerated expansion of the universe. For example galactic winds, jets, particle currents, and motions at great distances will seem to be extraordinarily fast including superluminous, but instead would be just another condition of The Pan Theory of Relativity or related “measurement relativity.” The full implications of this condition of relativity are very numerous and many may not be discussed within this text (discussions and evidence, pages 38-41, 97-102; 105)
27. The age of the oldest stars within the observable universe, some possibly within our own galaxy, could be 60 billion years old or more, born from a previous galaxy, now expired. These K and M dwarf stars would be few and far between. Their defining characteristic is their small size and luminosity, but this also makes them hard to detect. To recognize the oldest of these stars we would look at the ratio of their chemical makeup. If they are calculated to be fussing hydrogen at a certain rate based upon their radiation, they should have no more than a calculated amount of helium in their body even if they were the first stars formed in the universe. If the amount of helium observed is found to be many times the predicted quantity it would be strong evidence that the star is much older than the presently calculated age of the universe. (discussions and evidence pages 32-35)(106-107)
forrest_forrest@netzero.net
your friend forrest
May 14th, 2008 at 5:45 pm
@ forrest:
I was referring to real, peer-reviewed science. Which keeps me too busy as it is.
May 14th, 2008 at 10:29 pm
Torbjörn,
Congratulations on your honorary Order of Merit award.
Keep my predictions and my e-mail address. You will soon have need for them; I can tell you where to look and provide the calculations your may want when BB cosmology starts going south. An American expression for going awry. At that time many will be bewildered
your friend forrest