Webb Discovers One of the Universe's First Galaxies (phys.org) 46
Astronomers using the James Webb Space Telescope have identified an ultra-faint galaxy seen just 800 million years after the Big Bang. The galaxy contains almost no heavy elements, shows signs of intense early stellar radiation, and could offer a rare glimpse into the first stages of galaxy formation. Phys.org reports: In a paper published in the journal Nature, a team of scientists led by Kimihiko Nakajima, an astronomer at Kanazawa University, Japan, describes how they used the telescope to study a part of the deep universe and discovered a faint galaxy called LAP1-B. "LAP1-B establishes a 'fossil in the making,' a direct high-redshift progenitor of the ancient ultra-faint dwarf galaxies observed in the local universe," they wrote. Because the galaxy is so small and distant, it would normally be impossible to see. However, it was spotted due to a phenomenon known as gravitational lensing, in which a massive cluster of closer galaxies acts like a giant magnifying glass, boosting the light from LAP1-B by 100 times.
The scientists realized that most of the light from the galaxy wasn't coming from the stars, but from glowing clouds of gas. They analyzed this light by splitting it into a spectrum and studying the emission lines, which revealed the chemical composition of the gas. They found that the galaxy contains almost no heavy elements, and its oxygen abundance is about 240 times lower than the sun's, making it one of the most primitive star-forming galaxies ever observed. The emission lines also revealed intense ionizing radiation, which is what scientists expect to see from the first generation of stars.
The team also measured an elevated carbon-to-oxygen ratio. This matches the predicted chemical signature for the first star explosions in history from Population III stars, the first stars to exist in the universe. The stars we see today are Population I stars, which formed later and contain more heavy elements. Another fascinating finding is that, after measuring the gas's motion and speed, the researchers concluded that the galaxy is held together by a massive cloud of invisible dark matter.
The scientists realized that most of the light from the galaxy wasn't coming from the stars, but from glowing clouds of gas. They analyzed this light by splitting it into a spectrum and studying the emission lines, which revealed the chemical composition of the gas. They found that the galaxy contains almost no heavy elements, and its oxygen abundance is about 240 times lower than the sun's, making it one of the most primitive star-forming galaxies ever observed. The emission lines also revealed intense ionizing radiation, which is what scientists expect to see from the first generation of stars.
The team also measured an elevated carbon-to-oxygen ratio. This matches the predicted chemical signature for the first star explosions in history from Population III stars, the first stars to exist in the universe. The stars we see today are Population I stars, which formed later and contain more heavy elements. Another fascinating finding is that, after measuring the gas's motion and speed, the researchers concluded that the galaxy is held together by a massive cloud of invisible dark matter.
Would be more interesting (Score:3, Interesting)
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We have already. It turns out the previous universe is run by alien cats. Admittedly they look no different from our current cats but that is just to fool us.
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We have already. It turns out the previous universe is run by alien cats. Admittedly they look no different from our current cats but that is just to fool us.
The previous universe..was run by the assholes of the animal kingdom?
(Yeah. We give them credit in history. But not enough for that trait.)
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Re:Would be more interesting (Score:5, Funny)
if they see a galaxy 800 million years before the Big Bang.
Different era - that would be the Big Foreplay.
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if they see a galaxy 800 million years before the Big Bang.
Different era - that would be the Big Foreplay.
My kingdom for a mod point. Have an 'atta boy' instead. I needed that laugh.
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if they see a galaxy 800 million years before the Big Bang.
Different era - that would be the Big Foreplay.
My kingdom for a mod point. Have an 'atta boy' instead. I needed that laugh.
Same here
The researchers concluded... Hmmm. (Score:1, Troll)
IOW, the researchers don't know what holds the galaxy together.
Re:The researchers concluded... Hmmm. (Score:4, Insightful)
Correct. That is why they call it "dark matter".
Perhaps they should have called it "mysterious matter"?
Fact is there is either "more gravity" the there should be (or can be explained by looking at the visible atter), hence the term "dark matter" (as the matter is - seems to be - invisible) -or- there is an entire unknown force working ... with similar properties like gravity.
Which it is, we don't know.
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But the social sciences get funding just the same.
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Unite behind figuring out scientific mysteries.
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I just wish the non-scientific "sciences" would admit that they don't actually know as fast as the scientific sciences do. It's often quite important.
It would save many lives:
Society: "Will this murderer commit murder again if we let him out of prison ?"
Psychologists: No, let him out.
Actual answer: We don't know but there's a good chance he will, keep him in.
Oh, and sig fits.
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Re: The researchers concluded... Hmmm. (Score:3)
Knowledge is hard won in science. And it takes quite a bit of intellectual honesty to admin we don't know what something is. Dark matter is the label for phenomenon we can measure but we don't understand. It will be renamed when we do understand its nature.
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There is a need for educated guessers, regardless of what we call them. The alternative is clueless guessers, who give us tariff inflation and stupid wars.
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"We don't know" is the most important statement in science. As opposed to "absolutely, this is true and if you don't believe it you're a bad person."
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Negative. The most important statement in science is "That's strange ....".
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You never get to the point of saying "that's strange" if you can't say "I don't know."
Examples: the discovery of ergot fungus, for centuries attributed to demonic posession or divine punishment; the helicentric solar system, resisted despite centuries of strange behaviour of the planets because of hubris and some old Greek dude; physicians washing their hands between performing autopsies and delivering babies, because lol, what a dumb idea.
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That is why we unite behind: we don't know.
But if you do know: why are you not telling us and farm in your Nobel Prize?
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You are talking about MACHOs massive, compact halo objects, one of the candidates for dark matter. However, given the apparent amount of missing mass, from what I gather if it was all small black holes then we'd expect to see a certain amount of direct interactions with light, and those don't show up. That rules out the hypothesis of it all being explained by those.
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It did to cosmologists as well, so they studied that possibility. Evidence has mostly ruled it out, but there's still a window where it could be true.
https://www.frontiersin.org/jo... [frontiersin.org]
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Or... and hear me out: Maybe we do not fully understand the nature of gravity (and time). We may be blinded by what we "know".
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Same result.
There is some extra force, where do not know about where it comes from.
If it was gravity itself, then it would be pretty odd, as would kind of randomly be different at different places.
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That probably implies a shit-ton of earlier extra large blue giants had quickly, in a few million years, gone supernova to become a shit-ton of large black-holes.
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IIUC (I'm no specialist in the field!!):
No, but one of the possible meanings of "dark matter" is "black holes created during the big bang". It's tricky to make it work, and it requires some adjustment in how stable black holes are, but it's possible. The problem is that it would require that they evaporate more quickly and quietly than theory says that they should.
Note that these would be relatively small black holes. Possibly the larger ones became the nuclei around which the first generation of stars c
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Re: The researchers concluded... Hmmm. (Score:1)
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And now we don't understand how the galaxy we are in sticks together, and haven't for, what, 50+ years.
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And now we don't understand how the galaxy we are in sticks together, and haven't for, what, 50+ years.
It's not gravity?
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Re: The researchers concluded... Hmmm. (Score:2)
Plain old gravity. Just not certain if the elementary particles in the standard model are the source.
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Re: The researchers concluded... Hmmm. (Score:5, Informative)
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Dark matter is not common matter that is simply sparse. There's lots of ways to see clouds of gas or other sparse particles, such as by spectral absorption.
The trouble with dark matter is that it only seems to interact with gravity, and thus it does not qualify as a traditional form of matter. Calling it a "material" is speculation. It could be a form of energy we simply haven't discovered yet.
Until we have a better explanation, it's pretty close to magic, and it certainly does violate physics... at leas
That dark matter (Score:3)
Eventually weâ(TM)ll figure out itâ(TM)s just electromagnetic forces running through plasmas.
Ugh, scientific orthodoxy is harder to crack than religion
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Hey, we've got to enlighten them all about the cubical nature of time first before we can get them to accept the electric universe.
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A trillion pairs of mismatched socks clinging together out of the dryer explains the star system attraction forces mistaken for "dark matter".
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Electromagnetic forces may play a role; however, they do not/can not explain the large scale structure of the universe. I do agree that more research needs to be performed.