Powerful Galaxies Found in Infrared 172
demachina writes "NASA's Spitzer Infrared space telescope has discovered 'a mysterious population of distant and enormously powerful galaxies radiating in the infrared spectrum with many hundreds of times more power than our Milky Way galaxy.' They are 80% of the way back to the big bang. They found them by comparing a visible and infrared scan of the sky and looking at the places where there was a big infrared signature and no visible one. They are shrouded in dust."
Other life forms are out there... (Score:4, Funny)
Re:Other life forms are out there... (Score:3, Funny)
Re:Other life forms are out there... (Score:3, Insightful)
so? (Score:2, Funny)
Re:so? (Score:2)
Re:so? (Score:1)
They're watching (Score:4, Funny)
So you really can't hide from the IRS
This story is not what you think... (Score:2, Funny)
Is it only me... (Score:3, Informative)
Re:Is it only me... (Score:2)
Good grief, they still do those?
Cure Part-1 [mozilla.org] - Cure Part-2 [mozdev.org] - Cure Part-3 [kolla.de]
Re:Is it only me... (Score:2)
I too am using Firefox with popups disabled, and the space site still had a popup - this for a supposed spyware remover (possibly a trojan, who knows?). The latest round of popups has gotten past the common blockers.
Firefox also said that it had blocked popups, so presumably some were stopped, just not that one.
Frankly, when a minor-league topical news site engages in such tactics, I start to question the veracity of their stories.
Re:Is it only me... (Score:2)
Re:Is it only me... (Score:2, Informative)
Re:Is it only me... (Score:2)
Is Dark Matter just hidden matter? (Score:4, Interesting)
Re:Is Dark Matter just hidden matter? (Score:3, Interesting)
Re:Is Dark Matter just hidden matter? (Score:1)
Re:Is Dark Matter just hidden matter? (Score:4, Informative)
Re:Is Dark Matter just hidden matter? (Score:2, Interesting)
sorta, 'earlier reflections of the universe, bouncing around the universe'
Re:Is Dark Matter just hidden matter? (Score:1)
Re:Is Dark Matter just hidden matter? (Score:4, Informative)
Re:Is Dark Matter just hidden matter? (Score:5, Informative)
Electromagnetic radiation takes many forms: radio, microwave, infrared, visual (what we see as "light"), UV, Xrays, gamma rays. They are all "light".
Sorry to be a pedant.
Re:Is Dark Matter just hidden matter? (Score:1)
Re:Is Dark Matter just hidden matter? (Score:4, Informative)
Re:Is Dark Matter just hidden matter? (Score:3, Insightful)
The reason that they seem so different to us is because their wavelengths are larger/similar to/smaller than various atoms and molecules that we can observe them interacting with, so the net effect can be drastically different. If someone we
Re:Is Dark Matter just hidden matter? (Score:3, Interesting)
You can see what I mean if you have certain types
Re:Is Dark Matter just hidden matter? (Score:2)
Modern digital cams also behave this way, but to a lesser degree.
Re:Is Dark Matter just hidden matter? (Score:2)
Re:Is Dark Matter just hidden matter? (Score:3, Informative)
Re:Is Dark Matter just hidden matter? (Score:4, Informative)
Re:Is Dark Matter just hidden matter? (Score:4, Informative)
This begs one to ask, if we keep finding these galaxies that are emitting energy but no light, is this dark matter or is it just normal matter that we just haven't been able to find yet? There might be a hell of a lot more dust out there than we thought there was originally.
Certainly some of the dark matter is in baryonic (i.e. normal) matter. In fact, it's interesting to note that the the first "missing matter" found was baryonic. While the rotation curves of spiral galaxies provide the most clear-cut evidence for missing matter at present, the history of the dark matter problem started much earlier, with Fritz Zwicky's observation that clusters of galaxies had to have a lot of mass not shining in the visible spectrum in order to be bound objects; their galaxies were moving too fast for clusters to be gravitationally bound objects otherwise. Then, starting in the 1960s, a significant fraction of that dark matter was found when it was discovered that the space between galaxies in clusters is filled with a 10-100 million degree gas (well, plasma) known as the intracluster medium or ICM. In very large clusters, the ICM can have several times as much mass as the mass of all the cluster galaxies. That was a good sized chunk of the missing matter on cluster scales, right there.
However, despite that, it still left most of the apparent mass of galaxy clusters unaccounted-for, a situation that remains today. And that's been the same story with pretty much all the dim or dark baryonic matter we've found since then: it's crucial to know about, since it has important things to tell us about the evolution of the Universe, the history of galaxy formation, etc., but it doesn't make a big impact on the dark matter problem. Our measurements of the compnents of the density of the Universe are at low redshift, and we don't know what the low-redshift counterparts of these high-redshift ultraluminous IR galaxies are. But if they turn out to be something we haven't yet detected, and thus it turns out we've underestimated the number of low-redshift galaxies by a factor of three (very doubtful), that still won't put an appreciable dent in the dark matter problem. There's just so much dark matter out there to find, compared to the amount of known baryonic matter.
Finally, it's worth noting that if baryonic matter were able to explain away all the dark matter, that would actually pose a serious problem for the standard relativistic hot big bang model. One of the observational lynchpins of the model is its set of predictions for light element abundances. We think we know all the relevant physics at the energies of nuclear processes; that, combined with the evolution of the background Universe as dictated by the Big Bang model, allows one to calculate the abundances of light elements. It turns out that the theory of Big Bang Nucleosynthesis is able to make pretty good predictions for the abundances of hydrogen, helium, lithium, etc., provided the density of the Universe in baryons is within a small range. The predicted values are significantly larger than the contribution to the mass density of the Universe from the luminous matter in galaxies, so we already expected that that there would be some baryonic dark matter. But the predicted values are also much much much smaller than the apparent density of the Universe in dark matter. In other worse, if Big Bang Nucleosynthesis is correct, you expect there to be baryonic dark matter, but you also expect much much more non-baryonic dark matter. Of course, that doesn't mean that all the dark matter isn't baryonic -- nature is under no obligation to follow our theories! -- but the theory's done reasonably well up to know, so it's worth remembering and is a reminder to be careful.
Re:Is Dark Matter just hidden matter? (Score:3, Interesting)
"observation that clusters of galaxies had to have a lot of mass not shining in the visible spectrum in order to be bound objects"
What is the problem here? Does an Oort cloud 'shine'? If the interstellar spaces were crowded with planet-sized bodies, would these 'shine'? Can't this 'missing matter' merely be rocky or icy crud between the stars? I've often suspected that interstellar navigation might be *extremely* dangerous due to such obsticals, but wouldn't they count as 'dark matter
Re:Is Dark Matter just hidden matter? (Score:5, Informative)
The hot intercluster medium IS hot, but temperture is a funny thing in some astronomical settings. In this case, the density of particles is so low, a better vacuum than you'd get in Earth laboratories, that the heat content would be pretty low. You wouldn't get incinerated, for instance. But a conventional thermometer wouldn't work either since it probably wouldn't get into thermodynamic equilibrium. It would radiate away its heat faster than the ambient gas could warm it.
Astronomers have excellent limits on the amount of normal matter, as the parent poster says. We've got an excellent idea what is out there based on emission in the far infrared, interstellar scintillation, absorption line studies, reddening studies, etc. We have very good limits on the Oort cloud density, too, from comet statistics. There are even a number of direct observations based on microlensing surveys, and there's a shadow survey, too, looking at large star fields. In short, we've got pretty good numbers and we're not going to discover that there's more normal dark baryonic matter out there than we already know about.
Re:Is Dark Matter just hidden matter? (Score:2)
Re:Is Dark Matter just hidden matter? (Score:3, Interesting)
The one caveat to this concerns the speed of the spaceship. If it approaches relativistic speeds, a pebble can hit like a mountain. In this situation, you'd want to have some kind of active shielding. I describe one such system in my novel Star Dragon, which is out in paperback or available from my website for free download.
Re:Is Dark Matter just hidden matter? (Score:2, Interesting)
Really? By very good you mean within multiple orders of magnitude - with lots of hand waving. No one can even agree on the method used to perturb comets from the Oort Cloud into visible orbits, so the statistics are more like guesses. We're only working with a sample space of ~50 comets that have been observed and quantified in all of human history, hardly something that you can base sound stats on. As far as I'm aware the current estimates for Oort Cloud
Re:Is Dark Matter just hidden matter? (Score:3, Informative)
The Oort cloud existence is on very solid footing. The numbers I'm aware of are 50-500 Earth masses, and since this is less than 1/1000 of a solar mass spread out over a huge volume, in discrete chunks, we can certainly address the probability of hitting something flying a space ship through it (whic
Re:Is Dark Matter just hidden matter? (Score:3, Informative)
"observation that clusters of galaxies had to have a lot of mass not shining in the visible spectrum in order to be bound objects"
What is the problem here? Does an Oort cloud 'shine'? If the interstellar spaces were crowded with planet-sized bodies, would these 'shine'? Can't this 'missing matter' merely be rocky or icy crud between the stars? I've often suspected that interstellar navigation might be *extremely* dangerous due to such obsticals, but wouldn't they count as 'dark matter'?
Certainly rock
Re:Is Dark Matter just hidden matter? (Score:2)
Its not as if its a cloud of hot, *dangerous*, plasma that is going to mess with your hull plating?
I'm just trying to understand if this is plasma as in hot glowy stuff that melts through things or not.
Excuse me, my education on plasma has mostly been Trek.
Re:Is Dark Matter just hidden matter? (Score:2)
IANAAP (Not an astrophysacist) but as I understand it, if an object doesn't reflect light then it absorbs it and reradiates the energy at different wavelengths (i.e. you'd be able to see the 'crud' as surely as you would see something reflective, just at different wavelengths).
Take, for exampl
Re:Is Dark Matter just hidden matter? (Score:2)
Right, so if you stuck your hand out there, it would feel cold, not hot, right? Even though its 'thousands of degrees hot plasma'?
Something i have always wondered (Score:4, Interesting)
How do we know where they really are? If any EM radiation takes time to get here... Our night sky view is a view of something that has never happened, is not happening now, and will not happen (at least the particular configuration we see). The same thing goes for our radio telescopes, thermal, x-ray, ect.
That galaxy they found could not even exist now, or it may actually be 180 degrees relative to where we see it now.
Am i just crazy? Or do we have NO hope of actually figuring out where things are unless we figure out how to use quantum mechanics somehow to do it?
Re:Something i have always wondered (Score:2, Insightful)
That's because Newtons laws [google.com] of gravity and motion are more-or-less perfect for ball catching. Where greater times, distances and speeds are involved Einstein's theory of relativity [google.com] becomes more useful.
Scientists hedge their bets on those laws and previous observations of stars and galaxies being good enough to estimate where this are now and where they were.
This could all be in my head and e
Re:Something i have always wondered (Score:3, Informative)
We know where they are by a process called Red-Shift [google.co.in]. Please note that there is nothing cal
Re:Something i have always wondered (Score:1)
The light only moves so fast, and (if|since) the galaxy moves, the only way to find how fast it moves is to look how much the light is distorted, due to the Doppler effect [wikipedia.org].
For more information, google turned up this [zamandayolculuk.com] page.
Re:Something i have always wondered (Score:1)
Re:Something i have always wondered (Score:3, Interesting)
See here [anu.edu.au] and here [uni-tuebingen.de].
Re:Something i have always wondered (Score:2)
You're not crazy. You just have no hope of actually figuring out much. Don't quit your day job and leave quantum machanics to others.
Re:Something i have always wondered (Score:2)
Re:Something i have always wondered (Score:2)
We must rename the milky way (Score:4, Funny)
Re:We must rename the milky way (Score:1)
Large Blobs of Heat? (Score:2, Funny)
So what exactly constitutes a galaxy now? I thought a galaxy had to be a collection of stars; which omit visible light?
Re:Large Blobs of Heat? (Score:3, Funny)
So? These ones are omitting visible light. :)
Re:Large Blobs of Heat? (Score:1)
Something tells me that they are already omitting visible light.
Kids these days. You send them to school, and they just chew on the books.
Re:Large Blobs of Heat? (Score:1)
Re:Large Blobs of Heat? (Score:1)
So how then can these be called galaxies? Aren't they nothing more than blobs of heat? I read the article, but I don't really understand it. Any actual astonomers out there who can expond for me?
And sorry 'bout the English.. It's Saturday.
Re:Large Blobs of Heat? (Score:3, Interesting)
Re:Large Blobs of Heat? (Score:2)
Re:Large Blobs of Heat? (Score:5, Informative)
All galaxies (with the exception of the recently discovered and dubiously titled "dark matter galaxy" mentioned here a few days ago) emit light at a wide variety of wavelengths, from radio all the way to gamma rays. The wavelengths at which a star emits is related to its temperature (google "blackbody radiation" or "planck spectrum"); other astrophysical processes can produce or modify passing emissions as well (molecular & plasma clouds, various types of "dead" stars like neutron stars, white dwarfs, etc. can create emissions due to non-blackbody radiation - google "bremstrahllung", "cerenkov", "synchrotron", etc.).
The reason that these particular galaxies are only visible in the infrared is that a) intervening dust reddens emissions across intergalactic (and, for that matter, INTRAgalactic) distances, and b) they are so far away that as the universe has expanded, the light traveling from them has been redshifted - stretched along with the spacetime through which they have been traveling. Thus, what we see as infrared now was originally of much shorter wavelength when it was emitted.
Hope that's useful, let me know if I can clarify.
Re:Large Blobs of Heat? (Score:2)
If they're just distant galaxies that have been redshifted (/reddened by dust absorption), why do we care?
Isn't this what's *supposed* to happen? "Apple observed falling, film at 11."
'Course, they mention that these galaxies are "100 times more powerful" than the Milky Way. Is that 100 times more luminous in the infrared than the Milky Way (which would make sense) or 100 times more luminous in the infrare
Re:Large Blobs of Heat? (Score:4, Informative)
That's a good question, and worth a better answer than I have time do do here (mbrother?). The short answer is that they're so far away that we're actually seeing galaxies as they were very early in the universe. When we look at nearby galaxies, we only see galaxies as they exist after billions (current estimates are, if I'm up to date, that galaxy evolution has been going on for around 13Gy) of years of evolution. By looking FAR AWAY, we're also looking BACK IN TIME, and are thus able to see things we'd otherwise have no ability to observe.
A surprising amount can be gleaned from spectroscopic analysis of faint, red (& ancient) galaxies. What ionization levels are observable? Do we see lots of heavy elements, or none at all? Such observations can also be very powerful probes of the stuff IN BETWEEN here and there. If we can make certain assumptions about the original emissions, then by looking at the OBSERVED emissions, we can infer, to some degree, the conditions in the intervening space (and time) between emitter and collector. There is lots of good work being done in this area currently.
Hope that helps, let me know if I can clarify!
Re:Large Blobs of Heat? (Score:2)
That makes sense, and I was thinking myself about some of the interesting tidbits one can glean from seeing a "newborn" galaxy.
Still, the article pitches the discovery as interesting solely as "OMG INFR4R3D SOURCE WTF BBQ!", which (as you've confirmed) isn't why this is significant.
Re:Large Blobs of Heat? (Score:2)
No apologies...I'm all for the "no stupid questions" maxim.
As for those being the only two possibilities: those are the two that leap to mind right off the bat, and I can't think of any reason why early galazies wouldn't have been emitting LOTS in the shorter wavelengths. In fact, I seem to recall that much of the recent literature suggests that early galaxies had a higher percentage of large, heavy, short-lived stars - which are very hot and emit largely in the UV. But
Enormously Powerful (Score:2)
Real Ultimate Power (Score:3, Funny)
2. Galaxies fight ALL the time.
3. The purpose of the Galaxy is to flip out and kill people.
Check out this site all about galaxies, REAL GALAXIES. This site is awesome.I can't stop thinking about Galaxies. These guys are cool; and by cool, I mean totally sweet.
Re:Real Ultimate Power (Score:2)
"...ALL the time..." Heh. Priceless.
It's kind of wierd to think (Score:3, Interesting)
Maybe we're just in a particularly lucky section of the Big Bang spew. Or maybe we can't observe light that far away because of gravitational effects on photons. Kind of makes you wonder if it's by design.
Re:It's kind of wierd to think (Score:2, Insightful)
They may even be transmitting, may have been for a looong time. By the time we recieve the transmission, they (or us) may become extinct.
Re:It's kind of wierd to think (Score:1)
Re:It's kind of wierd to think (Score:2)
It's out there but we won't see it (Score:1, Insightful)
When we look to the skies we are looking back in time. So even if another civilization 300 hundred light years away developed radio 200 years ago, we won't hear from them for another 100 years. And 300 light years is barely measurable as distance in the grand scheme of things.
Plus by all indications inter-stellar space
Re:It's out there but we won't see it (Score:2)
Less time elsewhere? That is meaningless statement. There is no such thing as a simultaneous event. It is not as if some "time" has passed since the events we are "presently" witnessing from a distance, as that implies that time is an absolute, and it isn't.
Time and space are desperately interwoven, and any attemp
Re:It's kind of wierd to think (Score:1)
i for one .. (Score:1)
Powerful? (Score:2, Funny)
You don't know the meaning of power till you've met my wife.
Yes, this is a troll.Age (Score:1)
Re:Age (Score:2)
And if anyone in that galaxy a billion light-years away is looking in our directions, perhaps they'll see what I looked like when I had hair.
Pop-under warning!!! (Score:1, Offtopic)
Re:Pop-under warning!!! (Score:2)
Re:Pop-under warning!!! (Score:2)
though I don't know whether Safari has the equivalent of FlashBlock that firefox does
Apparently there's PithHelmet [culater.net] for Safari, but I haven't tried it out yet. Going to now.
Their paper? (Score:3, Informative)
Re:Their paper? (Score:2)
everyone knows (Score:2, Funny)
galaxies full of dyson spheres? (Score:3, Interesting)
mysterious population! (Score:2, Funny)
demachina writes "NASA's Spitzer Infrared space telescope has discovered 'a mysterious population
.. i almost pissed myself...
Remote control (Score:2)
It's God's remote control.
Chip H.
'reminds me of Ashton-Tate vs Fox Software... (Score:2)
A while before our present Open Source S/W
movement's growth, Ashton-Tate's powerful
one (many will recall their dBASE family)
saw Fox Software's FoxBASE public demo...
FoxBASE was faster [& may have had fewer
bugs, as well]. A-T would soon feel the
pinch, as users jumped ship to Fox S-W.
But first, a law suit arose, in which
Fox was claimed to have stolen A-T's IP.
From memory, it turned out that the
US gov't owned the IP, so A-T lost.
Fox continued to grow & improve, ie,
until ac
Infrared or red-shifted? (Score:2)
Since the universe is expanding, the further an object is away from the observer, the greater its red-shift. Hubble came up with the idea that the visible universe isn't limited by what's visible... It's limited by the velocity-distance proportionality. At some point everything that would be visible has been completely red-shifted out of the visi
Re:Damn pop-ups (Score:2, Informative)
by Larry Klaes
Ithaca NY (SPX) Mar 02, 2005
A Cornell University-led team operating the Infrared Spectrograph (IRS), the largest of the three main instruments on NASA's Spitzer Space Telescope, has discovered a mysterious population of distant and enormously powerful galaxies radiating in the infrared spectrum with many hundreds of times more power than our Milky Way galaxy.
Their distance from Earth is about 11 billion light years, or 80 percent of the w
Re:Damn pop-ups (Score:3, Interesting)
Re:Damn pop-ups (Score:2)
It's the right thing to do.
Re:Misread: Powerful Galaxies Found in Ireland. (Score:1)
Re:Misread: Powerful Galaxies Found in Ireland. (Score:2)
Re:Misread: Powerful Galaxies Found in Ireland. (Score:2)
No, but powerful Ford Galaxies were found in the 1960s.
Re:How come? (Score:1)
Re:How come? (Score:1)
Re:How come? (Score:5, Informative)
The effect is called "dust reddening." I have some slides about it for the lastest entry (March 2) for my Astronomy 1050 class at my astronomy webpage [uwyo.edu] if you want to see examples.
Re:How come? (Score:2)
Re:Huh? (Score:4, Insightful)
The big bang is a theory, NOT fact.
You seem to equate 'theory' with 'guess'. Actually, the word 'theory' in a scientific context indicates an extremely well-tested, valid model of the natural world --- essentially, as close as one can possibly get to the truth behind what is going on. Newton's gravitation is a theory. Einstein's relativity is a theory. Maxwell's electromagnetism is a theory. Darwin's evolution is a theory.
In the specific case of the big bang, there is very strong evidence pointing towards its occurrence --- things like the uniform recession of the galaxies, and the cosmic microwave background (basically, an afterglow from the event itself). This is hard, cold evidence --- nothing unsound about it.
we don't know how big the universe is, so there would be no way to calculate a point of 'bang.'
In fact, we do know how big the Universe is. And furthermore, since spacetime itself was created in the big bang, the event didn't happen at a single point, but everywhere.