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Astronomers Spot Baby Galaxies Cradled In Dark Matter (phys.org)
An anonymous reader writes: Astronomers discovered a nest of monstrous baby galaxies 11.5 billion light-years away using the Atacama Large Millimeter/submillimeter Array (ALMA). The young galaxies seem to reside at the junction of gigantic filaments in a web of dark matter (abstract). These findings are important for understanding how monstrous galaxies like these are formed and how they evolve in to huge elliptical galaxies. The team found that their young monstrous galaxies seemed to be located right at the intersection of the dark matter filaments. This supports the model that monstrous galaxies form in areas where dark matter is concentrated. And since modern large elliptical galaxies are simply monstrous galaxies which have mellowed with age, they too must have originated at nexuses in the large scale structure.
when they're small.
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Is it not a matter of conjecture that these galaxies are forming in regions where dark matter is concentrated? - a reasonably well-founded conjecture perhaps, but not corroborated by any evidence beyond that which is the basis of the conjecture?
How are we doing on finding those dark matter filaments that supposedly lurk in our own solar system? Now that New Horizons has uploaded all its Pluto flyby JPGs and is sending the Raws, it could soon perform some experiment that would test this possibility.
I was of the impression we detect dark matter indirectly, by the orbital velocities of galaxies and by gravitational lensing effects.
How did we determine that dark matter forms filaments, and how did we map the positions of these filaments?
They hate it when you do that!
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Keep in mind that the universe has been expanding for all those years, so we and that galaxy has in essence been 'running' away from each other..
How is that trolling ? Title implies Dark Matter as a fact. Show me the proof for Dark Matter.
TFA uses an annoyingly vague term and fails to define it. How large are these galaxies?
This should be interesting...
Without cheating and using a search engine, what do you think dark matter is? No, not what it theoretically is but what it is? Meh, I'll save some time.
Dark matter isn't really *anything* so much as it is *something* and that something is subject to debate. However, it is *something* that we can neither see nor measure. That's where the name comes from. We can see that something is having an effect and, as yet, that somethingremains unknown. But something that we can neither see nor measure is, truly - no doubt about it, causing these effects (known as gravitational lensing).
What that substance is, is very much an unknown. However, for now, that substance (or substances) are called dark matter and is an inclusive term for known and unknown theories. No matter what it turns out to be, it is still dark matter.
Make sense? It's a bit confusing, I guess, but not really if you can get someone to explain it to you well. There are a few competing theories as to what it is, specifically, but the effect is absolutely, certainly, repeatably proven to be there. That effect is caused by something. That something is dark matter. It's a generic term for wont of a better descriptor.
Sorry, I'm not the most articulate but that's a summary as well as I think I can describe it without getting into some maths that won't be supported by the markdown here. I'm not a physicist but I have a layman's background and an almost scholarly interest.
"So long and thanks for all the fish."
The proof is the lensing. You're thinking that dark matter is something that it is not and that's not surprising given the reporting that I've seen on the subject. No, dark matter is real. What is *really is* is in question.
"So long and thanks for all the fish."
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If you think I voted for Trump because of this post, you're wrong. I voted for Dr. Jill Stein of the Green Party. Again.
No, what we have is a need for large amounts of matter to explain observations.
Well either that or we are wrong in our equations.
But since our equations are the best we can come up with and they seem to work for everything else, then there must be a whole lot of matter we can't see.
Lensing is a symptom of matter, but we knew that from the rotational speed of the edge of galaxies, which started the whole thing in the first place.
Once again however show me a direct observation of 'Dark Matter', there isn't AFAIK.
Chances the first team to get there will collect a Nobel prize.
Another answer is that maybe gravity waves are not real, but dark matter probably is..
Below the speed of light Special Relativity is one of the most accurate theories in physics - above the speed of light..
I've heard it described that if you have a 1 light-year long piece of solid lead and sent a neutrino down it, it would have only a 50% chance to interact with the lead.
Blocking gravity waves is akin to blocking gravity itself.
Dark Matter is a fact with 9 sigmas of confidence. We just don't know what it is.
Even if we found that large amount of matter (or any other reason), it'd still be "dark matter." Dark matter isn't really anything but a generic term that's used to describe what's causing the effects we're seeing per the microlensing. Also, I think someone's claimed to find dark matter filaments. I've not followed that closely as I prefer to wait a while before getting excited. I linked to it in a reply on this page somewhere.
At any rate, dark matter is - as far as I know, just a generic description that's based on what we're seeing. No matter what it turns out to be, it will have been dark matter. It might not even be matter at all. It's dark because we can't see it and it's matter because we don't know what else would cause this but, for now, it's just a description of an affect more than anything else. Others have sort of had a go at making it more than it is but it's a rather generic thing.
"So long and thanks for all the fish."
There is more evidence of dark matter than global warming. Look it up.
If information wants to be free, why does my internet connection cost so much?
I love how slashdot has a vehement anti-dark matter crowd. Truly bizarre thing to get quite so emotional about.
I do not want your cheap brainburning drugs. They are useless for work. And I am a working man today.
I just think you've hit on a particular bugbear for some people, such as CAHutch. They get angry that one of the possible explanations for things like galactic rotation curves is non-baryonic matter that interacts gravitationally but weakly or not at all with other forces. This makes them mad. Don't ask me why. Maybe it exists, maybe it doesn't, CAHutch has made up his mind already and he ain't for budging.
I do not want your cheap brainburning drugs. They are useless for work. And I am a working man today.
You aren't going to get a direct observation of something that doesn't interact with the electromagnetic force. No photons absorbed and none emitted.
I do not want your cheap brainburning drugs. They are useless for work. And I am a working man today.
I would fully expect your dark-matter-denier (which I didn't know existed until Slashdot) to also be an AGW denier. Makes sense. Therefore this probably won't help much as an argument. ;)
I do not want your cheap brainburning drugs. They are useless for work. And I am a working man today.