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James Webb Space Telescope Finds Most Distant Known Galaxy

blogs.nasa.gov

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Re: James Webb Space Telescope Finds Most Distant Known Galaxy

#21

Post by malfist »

astroH wrote: post #17
XzAeRosho wrote: post #4

>The presence of oxygen so early in the life of this galaxy is a surprise and suggests that multiple generations of very massive stars had already lived their lives before we observed the galaxy. For some reason this quote blew me away. It's just so hard to comprehend the timescales and vastness of the universe.

Multiple generations is perhaps an overstatement. The first oxygen in the Universe came from what we call Population III stars which is the first generation of stars to form after the Big Bang and what separates these from other stellar populations is that they do not have elements heavier than hydrogen or helium (except for minuscule traces left over from the Big Bang but these are insignificant). Now we don't know…

Big stars burn hot and fast, the more mass, the shorter their lives

Re: James Webb Space Telescope Finds Most Distant Known Galaxy

#22

Post by throwawaymaths »

malfist wrote: post #21
astroH wrote: post #17

Earlier quoted context omitted.

Multiple generations is perhaps an overstatement. The first oxygen in the Universe came from what we call Population III stars which is the first generation of stars to form after the Big Bang and what separates these from other stellar populations is that they do not have elements heavier than hydrogen or helium (except for minuscule traces left over from the Big Bang but these are insignificant). Now we don't know…

Big stars burn hot and fast, the more mass, the shorter their lives

Pop III stars (if they existed) are really a mystery, we can't easily extrapolate. These stars would be purely hydrogen and helium so it would take them a surprisingly long time to get to CNO cycle, for example.

Re: James Webb Space Telescope Finds Most Distant Known Galaxy

#23

Post by astroH »

throwawaymaths wrote: post #22
malfist wrote: post #21

Earlier quoted context omitted.

Big stars burn hot and fast, the more mass, the shorter their lives

Pop III stars (if they existed) are really a mystery, we can't easily extrapolate. These stars would be purely hydrogen and helium so it would take them a surprisingly long time to get to CNO cycle, for example.

So I think it is fair to say they did exist. If we believe in Big Bang Nucleosynthesis then heavy elements had to come from somewhere making the first generation of stars (whatever their properties may be) be Population III. I agree that without a catalyst it's hard to initiate the CNO cycle but indeed models predict that it is possible even under these circumstances.

Re: James Webb Space Telescope Finds Most Distant Known Galaxy

#24

Post by dylan604 »

vlovich123 wrote: post #11
XzAeRosho wrote: post #4

>The presence of oxygen so early in the life of this galaxy is a surprise and suggests that multiple generations of very massive stars had already lived their lives before we observed the galaxy. For some reason this quote blew me away. It's just so hard to comprehend the timescales and vastness of the universe.

It's interesting that [1] has a diagram showing that in 2022 the NASA diagram claimed that stars & galaxies formed 400M years ago so this feels like a big shift to having a massive galaxy already at 300M with data suggesting it's formed after several generations of stars. > All of these observations, together, tell us that JADES-GS-z14-0 is not like the types of galaxies that have been predicted by theoretical models…

> formed 400M years ago

do you mean formed 400M years after the big bang instead of 400M years ago from today? That's like yesterday to the Universe.

Re: James Webb Space Telescope Finds Most Distant Known Galaxy

#27

Post by perihelions »

- "Editor’s Note: This post highlights data from Webb science in progress, which has not yet been through the peer-review process."

Here's the preprint they won't link:

https://arxiv.org/abs/2405.18485 ("A shining cosmic dawn: spectroscopic confirmation of two luminous galaxies at z∼14")

Re: James Webb Space Telescope Finds Most Distant Known Galaxy

#28

Post by ajross »

nerdjon wrote: post #9

It is interesting to think about what could be from a galaxy that was formed ~500 million years before ours. If life had formed in that galaxy, if somehow it had followed a similar pattern we did (which is doubtful, but just a thought experiment for simplicity). It would be very interesting to see a glimps of where life could be with an "extra" 500 million years. Even just a few million considering homosapiens did no…

Just to rub it in, it's worse than that: it's always flying away from us, and it looks currently like that rate is accelerating. We don't even get to see this galaxy evolve, as we watch it will eventually appear to freeze in time from our perspective as it dims and red-shifts into the background radiation.

Re: James Webb Space Telescope Finds Most Distant Known Galaxy

#29

Post by Pompidou »

vlovich123 wrote: post #11
XzAeRosho wrote: post #4

>The presence of oxygen so early in the life of this galaxy is a surprise and suggests that multiple generations of very massive stars had already lived their lives before we observed the galaxy. For some reason this quote blew me away. It's just so hard to comprehend the timescales and vastness of the universe.

It's interesting that [1] has a diagram showing that in 2022 the NASA diagram claimed that stars & galaxies formed 400M years ago so this feels like a big shift to having a massive galaxy already at 300M with data suggesting it's formed after several generations of stars. > All of these observations, together, tell us that JADES-GS-z14-0 is not like the types of galaxies that have been predicted by theoretical models…

No. The diagram https://science.nasa.gov/resource/history-of-the-universe/ tells us that galaxies and dark matter formed 400M years after the big bang. Look at the right of the chart legend: "13.8 billion years" is above "today".

Re: James Webb Space Telescope Finds Most Distant Known Galaxy

#30

Post by vlovich123 »

dylan604 wrote: post #24
vlovich123 wrote: post #11

Earlier quoted context omitted.

It's interesting that [1] has a diagram showing that in 2022 the NASA diagram claimed that stars & galaxies formed 400M years ago so this feels like a big shift to having a massive galaxy already at 300M with data suggesting it's formed after several generations of stars. > All of these observations, together, tell us that JADES-GS-z14-0 is not like the types of galaxies that have been predicted by theoretical models…

> formed 400M years ago do you mean formed 400M years after the big bang instead of 400M years ago from today? That's like yesterday to the Universe.

Correct. Obviously not 400 mya.
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