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Old Yesterday, 05:05 PM   #241
Mike Helland
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Originally Posted by RecoveringYuppy View Post
No, we've already found it. Read your own links even.
Could you be more specific?

"This implies that disk galaxies have existed in large
numbers for quite a significant amount of time. This
may mean that the morphologies of some disk galaxies,
such as the Milky Way, have remained in their current
form for over 10 billion years. This would challenge our
ideas about mergers being a very common process, and
it might be the case that mergers are only a dominant
process for forming the stellar masses of certain types
of galaxies, namely spheroids, which have a relatively
constant merger fraction at z > 2.5 at around 10%. Al-
though on average galaxies should go through multiple
mergers over cosmic time (Duncan et al. 2019), it is
not clear how these mergers would affect disk morpholo-
gies or if there are only certain galaxies that go through
mergers multiple times while others, such as the disks
we find here, do not undergo these mergers very often
or at all at z < 6.


Our key findings are:
I. The morphological types of galaxies changes less
quickly than previously believed, based on precursor
HST imaging and results. That is, these early JWST re-
sults suggest that the formation of normal galaxy struc-
ture was much earlier than previously thought.

II. A major aspect of this is our discovery that disk
galaxies are quite common at z ∼ 3 − 6, where they
make up ∼ 50% of the galaxy population, which is over
10 times as high as what was previously thought to be
the case with HST observations. That is, this epoch is
surprisingly full of disk galaxies, which observationally
we had not been able to determine before JWST.

III. Distant galaxies at z > 3 in the rest-frame opti-
cal, despite their appearance in the HST imaging, are
not as highly clumpy and asymmetric as once thought.
This effect has not been observed before due to the na-
ture of existing deep imaging with the HST which could
probe only ultraviolet light at z > 3. This shows the
great power of JWST to probe rest-frame optical where
the underlying mass of galaxies can now be traced and
measured."

https://arxiv.org/abs/2207.09428
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Old Yesterday, 05:51 PM   #242
RecoveringYuppy
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Originally Posted by Mike Helland View Post
Could you be more specific?
Why? It never gets through to you. Metallicity, galaxy size, and star formation rates, for example. This has been beaten to death over many months or years with you.
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Old Yesterday, 06:21 PM   #243
Mike Helland
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Originally Posted by RecoveringYuppy View Post
Metallicity, galaxy size, and star formation rates
We expect the most distant galaxies to be metal poor, but like I said, JWST contradicts that

https://www.nature.com/articles/d41586-022-02056-5

Quote:
And studies of galactic chemistry also show a rich and complicated picture emerging from the Webb data. One analysis of the first deep-field image examined the light emitted by galaxies at a redshift of 5 or greater. (Spectral lines that appear at various wavelengths of light correlate with the chemical elements composing the galaxies.) It found a surprising richness of elements such as oxygen11. Astronomers had thought that the process of chemical enrichment — in which stars fuse hydrogen and helium to form heavier elements — took a while, but the finding that it is under way in early galaxies “will make us rethink the speed at which star formation occurs”, Kirkpatrick says.
We expect the oldest galaxies to be small and closer galaxies to be bigger, but JWST contradicts that.

Quote:
Another preprint manuscript suggests that massive galaxies formed earlier in the Universe than previously known. A team led by Ivo Labbé at the Swinburne University of Technology in Melbourne, Australia, reports finding seven massive galaxies in the CEERS field, with redshifts between 7 and 1010. “We infer that the central regions of at least some massive galaxies were already largely in place 500 million years after the Big Bang, and that massive galaxy formation began extremely early in the history of the Universe,” the scientists write.

...

The surprises from Webb continue even a little later in the Universe’s evolution. One study looked at Webb’s observations of ‘cosmic noon’, the period approximately three billion years after the Big Bang. This is when star formation peaked in the Universe, and the most light was created.

Wren Suess, an astronomer at the University of California, Santa Cruz, compared Hubble images of galaxies at cosmic noon with Webb images of the same galaxies. At the infrared wavelengths detected by Webb, most of the massive galaxies looked much smaller than they did in Hubble images12. “It potentially changes our whole view of how galaxy sizes evolve over time,” Suess says. Hubble studies suggested that galaxies start out small and grow bigger over time, but the Webb findings hint that Hubble didn’t have the whole picture, and so galactic evolution might be more complicated than scientists had anticipated.
Regarding star formation, what specifically do you expect to see?

Observations show active and inactive (quiescent) galaxies at all observable distances. The inactive ones are harder to see, because they're not as bright. But we've been finding them:

https://arxiv.org/abs/1312.4952

"We report the likely identification of a substantial population of massive M~10^11M_Sun galaxies at z~4 with suppressed star formation rates (SFRs), selected on rest-frame optical to near-IR colors from the FourStar Galaxy Evolution Survey. "

https://www.sci.news/astronomy/extre...rse-08091.html

“More remarkably, we show that XMM-2599 formed most of its stars in a huge frenzy when the Universe was less than one billion years old, and then became inactive by the time the Universe was only 1.8 billion years old.”

Your information is a decade or two out of date.
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Old Yesterday, 06:36 PM   #244
RecoveringYuppy
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You're simply demonstrating you can't learn. All of that has been addressed already. And not to mention the fact that you are trusting early results (not that I expect them to contradicted, but still).

More oxygen at redshift 5 than expected is not more or equal to now.

And some small numbers of large galaxies then is not the same as the number of galaxies now.

We aren't even scratching at science here, these are failure of your understanding of English. And I'm pretty damn sure I saw someone else point this out to you already in the past week.
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Old Yesterday, 06:53 PM   #245
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Well, I suppose it's what one gets when their understanding of science is based on vague words like "massive" or "early" or some vaguely defined version of light getting tired SOMEHOW. That's why the rest of the world uses MATHS for this kind of thing.
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Old Yesterday, 06:56 PM   #246
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My dude tryna play formal logic games with natural language, like that makes him a kind of physicist.
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Old Yesterday, 07:01 PM   #247
Mike Helland
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Originally Posted by RecoveringYuppy View Post
More oxygen at redshift 5 than expected is not more or equal to now.
Ok. So what's the difference between now and then?

Shouldn't there be a difference between z=2 and z=5?

"The z > 5 metallicities are broadly consistent
with z ∼ 2 galaxies of similar stellar mass, although our in-
terpretation is limited by highly uncertain stellar masses and
upper limits in metallicity."

https://arxiv.org/abs/2207.12388

Quote:
And some small numbers of large galaxies then is not the same as the number of galaxies now.
"On the stunning abundance of super-early, massive galaxies revealed by JWST"

https://arxiv.org/abs/2208.00720

"A first look at JWST CEERS: massive quiescent galaxies from 3 < z < 5 "

https://arxiv.org/abs/2208.00986
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Old Yesterday, 07:17 PM   #248
HansMustermann
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Originally Posted by Mike Helland View Post
Ok. So what's the difference between now and then?

Shouldn't there be a difference between z=2 and z=5?

"The z > 5 metallicities are broadly consistent
with z ∼ 2 galaxies of similar stellar mass, although our in-
terpretation is limited by highly uncertain stellar masses and
upper limits in metallicity."
Heh. It's not that often that you see anyone else actually offering a quote that would tell them where they went wrong, if they only had any clue what they're talking about.

Key words there: "and upper limits in metallicity."

Yeah, there is an upper limit on solar mass based on metallicity. So, considering that you want it to also ignite to something you can actually see, yeah, that puts an upper limit that it converges towards. Fairly soon too, since the biggest jump in metallicity was when the Pop 3 stars blew up, and, as said before, those only lasted 2 to 5 million years. Not billion, but million.
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Old Yesterday, 08:45 PM   #249
RecoveringYuppy
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Originally Posted by Mike Helland View Post
Ok. So what's the difference between now and then?
For crying out loud. You tell me. You're the guy claiming we know. What I know is that the instrument to measure that era just started returning data last month.

Originally Posted by Mike Helland View Post
Shouldn't there be a difference between z=2 and z=5?
I'm not bothering reading in to that but I note the abstract points out differences.

Originally Posted by Mike Helland View Post
"On the stunning abundance of super-early, massive galaxies revealed by JWST"
Not reading in to that in detail either. At first glance it looks like you just repeated the massive English fail that I just pointed out. "Unexpected for then" is different from "same as now".
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Old Yesterday, 09:20 PM   #250
Mike Helland
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Originally Posted by RecoveringYuppy View Post
For crying out loud. You tell me. You're the guy claiming we know.
Not quite. You claimed we see evidence of galaxy evolution. I asked you be specific, and you said metal content.

We don't actually see that though. That's what we expect to see.

Quote:
What I know is that the instrument to measure that era just started returning data last month.
Indeed. And are astronomers seeing what they expected?
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Old Yesterday, 10:15 PM   #251
RecoveringYuppy
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Originally Posted by Mike Helland View Post
Not quite. You claimed we see evidence of galaxy evolution. I asked you be specific, and you said metal content.

We don't actually see that though. That's what we expect to see.
We've already looked. JWST is not the first instrument capable of looking at this. We expect to see an early timeframe at greater detail than every before.

Here is just one example from a quick google: https://ui.adsabs.harvard.edu/abs/20......9P/abstract

That's literally just the first thing I came across but it has the benefit or putting the lie to your claim that cosmologists are in denial.

Originally Posted by Mike Helland View Post
Indeed. And are astronomers seeing what they expected?
This has been answered in great detail. And why do you think I just told you this instrument has only been on for a month?
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Old Yesterday, 10:33 PM   #252
Mike Helland
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Originally Posted by RecoveringYuppy View Post
Here is just one example from a quick google: https://ui.adsabs.harvard.edu/abs/20......9P/abstract
Oxygen makes up 1% of the Milky Way (98% H and He, 1% everything else).

Wouldn't that mean that oxygen should be undetectable at z=5?

"The best linear fit rate to metallicity vs. redshift is −0.26 ± 0.06 dex corresponding to approximately a factor of 2 every Gyr at z = 3. The DLA continue to maintain a floor in metallicity of ≈ 1/700 solar independent of observational effects. This metallicity threshold limits the prevalence of primordial gas in high redshift galaxies and stresses the correspondence between damped systems and star formation (i.e. galaxy formation). This floor is significantly offset from the metallicity of the Lyα forest and therefore we consider it to be more related to active star formation within these galaxies than scenarios of enrichment in the very early universe."

Based on what was observable at those distances in 2003 when this was published, I think the JWST results will supercede this.

I had to find out what a dex is.

https://joe-antognini.github.io/astronomy/what-is-a-dex

The term “dex” comes up rather frequently in astronomy discussions but is rarely defined in textbooks. The idea of a dex is straightforward—a dex is simply an order of magnitude. More formally, a difference of x dex is a change by a factor of 10x.

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Old Yesterday, 10:59 PM   #253
RecoveringYuppy
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What's oxygen got to do with this? Oxygen will appear before iron and currently there is more oxygen than iron.
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Old Yesterday, 11:03 PM   #254
Mike Helland
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Originally Posted by RecoveringYuppy View Post
What's oxygen got to do with this?
Um, seriously? You said in message 244:

"More oxygen at redshift 5 than expected is not more or equal to now."

http://www.internationalskeptics.com...&postcount=244

This came up because JWST:

https://www.nature.com/articles/d41586-022-02056-5

And studies of galactic chemistry also show a rich and complicated picture emerging from the Webb data. One analysis of the first deep-field image examined the light emitted by galaxies at a redshift of 5 or greater. (Spectral lines that appear at various wavelengths of light correlate with the chemical elements composing the galaxies.) It found a surprising richness of elements such as oxygen. Astronomers had thought that the process of chemical enrichment — in which stars fuse hydrogen and helium to form heavier elements — took a while, but the finding that it is under way in early galaxies “will make us rethink the speed at which star formation occurs”, Kirkpatrick says.
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Old Yesterday, 11:07 PM   #255
RecoveringYuppy
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244 is a different post. You were quoting post 251.
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Old Yesterday, 11:12 PM   #256
Mike Helland
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Originally Posted by RecoveringYuppy View Post
244 is a different post. You were quoting post 251.
We were talking about metallicity, and the JWST new revalations. Oxygen specifically. (Yes, to anyone that may not know, oxygen is a metal as far as astronomers are concerned. Anything heavier than helium is.)

But I can take a hint. You're looking for the escape hatch.
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Old Yesterday, 11:14 PM   #257
RecoveringYuppy
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Post 251 is not about oxygen. I have never restricted the conversation to oxygen.
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Old Yesterday, 11:22 PM   #258
Mike Helland
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Originally Posted by RecoveringYuppy View Post
Post 251 is not about oxygen. I have never restricted the conversation to oxygen.
I never said you did. It's an example of a metal referenced in the paper.

Whatever. I think we're done here.
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Old Today, 05:10 AM   #259
HansMustermann
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Originally Posted by Mike Helland View Post
Oxygen makes up 1% of the Milky Way (98% H and He, 1% everything else).

Wouldn't that mean that oxygen should be undetectable at z=5?
Err... why would it be? Let's look at what your own quote says:

Originally Posted by Mike Helland View Post
"The best linear fit rate to metallicity vs. redshift is −0.26 ± 0.06 dex corresponding to approximately a factor of 2 every Gyr at z = 3."
z=3 is about 11.476 billion years ago
z=5 is about 12.469 billion yeas ago

(Source: https://lco.global/spacebook/light/redshift/)

That's almost exactly 1 billion years difference.

Your own quote says the best fit is approximately a factor of 2 every billion years. (That's what that Gyr means.)

Ergo, there should be half the metallicity at z=5 compared to z=3.

Well, ok, that's the simplified and inaccurate version, because it's not a line (except in logarithmic coordinates), so taking the tangent in one point and extrapolating that is not gonna get us the right value. Let's go back to that −0.26 ± 0.06 dex per redshift units. There are 2 units between z=3 and z=5, so the difference is approximately 10-0.52=0.3 as much metallicity at z=5 as at z=3.

I'm not sure why you think halving it would be undetectable. Not the least because that paper talks about some "damped systems" which are about 10x less than expected at their respective redshift. We could obviously detect those, or we wouldn't be talking about it.

So please explain to me exactly what kind of confusion of mind leads you to believe that ok, we can detect 0.1x just fine, but we totally couldn't detect 0.3x? For that matter, what kind of confusion of mind would lead you to believe that, given a paper that plots exactly those values on a graph, we wouldn't be able to detect them?


I'm guessing you probably thought that they mean 2 orders of magnitude when they said "dex" and then "factor of 2" in the same sentence. Not noticing that the dex is the unit for a different number, and for a different denominator.


Finally, note that even the paper tells you that actually the values are spread all over the place. That you can fit a line through a data set and show a trend, doesn't mean that every single point is on that line. It's why they talk about those damped systems. That's why you can't do your trademark idiocy of taking one outlier and proclaiming that all galaxies at that distance are like that.
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Old Today, 06:40 AM   #260
RecoveringYuppy
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Originally Posted by HansMustermann View Post
Err... why would it be? Let's look at what your own quote says:
Did you read my citation yourself or are you just trusting MH's interpretation of it? Don't trust MH's interpretation has a flaw.

Your post still stands though and accounting for his mistake will make your argument stronger.
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Old Today, 06:52 AM   #261
Mike Helland
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Originally Posted by HansMustermann View Post
There are 2 units between z=3 and z=5, so the difference is approximately 10-0.52=0.3 as much metallicity at z=5 as at z=3.
But there are 5 units of redshift between z=0 and z=5.

The Milky Way is 1% oxygen at z=0.
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Old Today, 07:23 AM   #262
HansMustermann
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Originally Posted by RecoveringYuppy View Post
Did you read my citation yourself or are you just trusting MH's interpretation of it? Don't trust MH's interpretation has a flaw.
Well, I'm too much of a paranoid bastard to trust quotes on the Internet. I went and read the PDF.
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Old Today, 07:40 AM   #263
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Originally Posted by Mike Helland View Post
But there are 5 units of redshift between z=0 and z=5.

The Milky Way is 1% oxygen at z=0.
1. The paper said they studied stuff between z=0.5 and z=5, not at z=0. (Though it does mention in passing a study by someone else at z=0)

2. Nevertheless, even extrapolating that, -0.26 dex per z unit would give you a whole -1.3 dex between z=0 and z=5. And 10-1.3=0.05, or about 1/20. (And I'll even ignore the metallicity floor for now.)

I still don't know what kind of confusion of mind would make you think that's undetectable. We have in fact had no problem measuring it in stars (albeit MUCH closer ones) with 1/1000 the metallicity of the Sun.

3. Not the least, because the paper plotted exactly those values. Including outliers which were 1/10 of the expected values.

Seriously, exactly from how high does one need to dropped on their head as a baby, to claim essentially "here's a paper which measured and plotted exactly those values, and even values 1/10 of those, therefore they're too small to measure"?

4. Even more importantly, the paper does say that there's that average 10-0.26=0.55x decrease in metallicity per unit of z. Stars further back ARE on the average exhibiting less metallicity than than stars close by. In fact, here's a quote from page 5 saying it point blank: "The results indicate that the metallicity of the ‘average’ galaxy is increasing with decreasing redshift"

What kind of confusion of mind makes you read that and conclude it supports your polar opposite idiocy, namely that we're seeing roughly the same old galaxies all the way back? How confused does one need to be to claim X and bring up a paper saying flat out NOT X as support?
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Old Today, 07:56 AM   #264
Mike Helland
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Originally Posted by HansMustermann View Post
How confused does one need to be to claim X and bring up a paper saying flat out NOT X as support?
The 2003 paper? I didn't bring it up.

This is what I brought up:

Quote:
And studies of galactic chemistry also show a rich and complicated picture emerging from the Webb data. One analysis of the first deep-field image examined the light emitted by galaxies at a redshift of 5 or greater. (Spectral lines that appear at various wavelengths of light correlate with the chemical elements composing the galaxies.) It found a surprising richness of elements such as oxygen. Astronomers had thought that the process of chemical enrichment — in which stars fuse hydrogen and helium to form heavier elements — took a while, but the finding that it is under way in early galaxies “will make us rethink the speed at which star formation occurs”, Kirkpatrick says.
https://www.nature.com/articles/d41586-022-02056-5
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Old Today, 07:59 AM   #265
RecoveringYuppy
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Originally Posted by Mike Helland View Post
The 2003 paper? I didn't bring it up.
But it's what you're citing now to support the arguments you are making now and it was brought up in response to your question.
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Old Today, 08:04 AM   #266
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Originally Posted by RecoveringYuppy View Post
But it's what you're citing now to support the arguments you are making now and it was brought up in response to your question.
Sorry, you brought up the 2003 paper to refute the 2022 paper.

Their conclusion (2022) is:

"The z > 5 metallicities are broadly consistent with z ∼ 2 galaxies of similar stellar mass, although our interpretation is limited by highly uncertain stellar masses and upper limits in metallicity."

https://arxiv.org/abs/2207.12388

But if you prefer the 2003 data, I totally understand.
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Old Today, 08:13 AM   #267
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Which Nature article in turn references the same one: https://arxiv.org/abs/2207.12388

Which says this right on page 1 of the actual PDF: "Galaxies at 1 < z < 3.5 have lower metallicity than z ∼ 0 galaxies of the same stellar mass".

And this on page 5: "In Section 4 we compare our new z > 5 line-ratio measurements with previous observations at lower redshift and with theoretical photoionization models, finding that the high-redshift galaxies have very high ionization (log(Q/[cm s−1]) ∼ 8 − 9) and low (but nonzero) metallicities (Z/Z ∼ 0.1)."

So, as RecoveringYuppy was trying to tell you, even when it's saying that something is surprisingly high (or low) for back then, it's NOT the same thing as saying it's at the same levels at today.

But, you know, you'd have to read at least the first couple of pages of the actual science paper to notice that

Hell, you'd have to read and comprehed at least the short abstract at the top to notice that the whole point is that yes there are difference in the spectral bands of older galaxies. One band is similar, at least two are not, which further implies other differences, such as the very high ionization back then compared to now. THAT is what that paper says. It's the polar opposite of your idiotic postulate that we're seeing the same things at any distance. That paper says that no, we do not.

So reserve the sarcasm for when you've actually understood what you're citing, not when you have no clue what that one is talking about either.
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Old Today, 08:19 AM   #268
RecoveringYuppy
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Originally Posted by Mike Helland View Post
Sorry, you brought up the 2003 paper to refute the 2022 paper.
No. I did not. The 2022 paper is fine. Damn you can't read. Not the papers, not the posts in the thread. No reading comprehension at all.

I was answering your repeated question asking if we have already observed metallicity disparities prior to JWST. The answer is yes.

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Old Today, 08:34 AM   #269
Mike Helland
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Originally Posted by HansMustermann View Post
Which Nature article in turn references the same one: https://arxiv.org/abs/2207.12388

Which says this right on page 1 of the actual PDF: "Galaxies at 1 < z < 3.5 have lower metallicity than z ∼ 0 galaxies of the same stellar mass".

And this on page 5: "In Section 4 we compare our new z > 5 line-ratio measurements with previous observations at lower redshift and with theoretical photoionization models, finding that the high-redshift galaxies have very high ionization (log(Q/[cm s−1]) ∼ 8 − 9) and low (but nonzero) metallicities (Z/Z ∼ 0.1)."

So, as RecoveringYuppy was trying to tell you, even when it's saying that something is surprisingly high (or low) for back then, it's NOT the same thing as saying it's at the same levels at today.

But, you know, you'd have to read at least the first couple of pages of the actual science paper to notice that

Hell, you'd have to read and comprehed at least the short abstract at the top to notice that the whole point is that yes there are difference in the spectral bands of older galaxies. One band is similar, at least two are not, which further implies other differences, such as the very high ionization back then compared to now. THAT is what that paper says. It's the polar opposite of your idiotic postulate that we're seeing the same things at any distance. That paper says that no, we do not.

So reserve the sarcasm for when you've actually understood what you're citing, not when you have no clue what that one is talking about either.
Fair enough.

So if the Milky Way is 1% oxygen, is it agreed that we should expect z=5 galaxies to have 0.05% oxygen?
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Old Today, 08:46 AM   #270
RecoveringYuppy
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Originally Posted by Mike Helland View Post
Fair enough.

So if the Milky Way is 1% oxygen, is it agreed that we should expect z=5 galaxies to have 0.05% oxygen?
What does oxygen have to do with it?
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Old Today, 09:56 AM   #271
Mike Helland
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Originally Posted by RecoveringYuppy View Post
What does oxygen have to do with it?
According to this:

https://www.sciencealert.com/scienti...n-the-universe

"But while oxygen was present, it was found in very small amounts, being 10 times less abundant than it is in the Sun."

That galaxy is at z>7.

How do they determine the abundance? Whether its 1% or 0.1%? Is it the intensity of the emission lines?
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Old Today, 10:13 AM   #272
RecoveringYuppy
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I was asking you about post 269 directly ahead of the one where I asked the question. Answer the question.

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