Forming stars in the early universe

Forming stars in the early universe
A Hubble image of a field of distant galaxies. A new study of the gas content in galaxies so distant their light has been traveling for about ten billion years suggests that the processes converting gas into stars is about the same back then as in the local universe. Credit: NASA, ESA, G. Illingworth (UCO/Lick & UCSC), R. Bouwens (UCO/Lick & Leiden U.), and the HUDF09 Team

The first stars appeared about one hundred million years after the big bang, and ever since then stars and star formation processes have lit up the cosmos. When the universe was about three billion years old, star formation activity peaked at rates about ten times above current levels. Why this happened, and whether the physical processes back then were different from those today or just more active (and why), are among the most pressing questions in astronomy. Since stars are made from gas, the gas content of galaxies is a measure of their star formation potential and (at least in the local universe) the fraction of matter in form of gas, the "gas fraction", is a measure of the star formation capability.

Gas in galaxies is depleted as new stars are formed and as some of it is blown out of the system by supernovae or by winds; gas can also be added by infall from the intergalactic medium. These processes are roughly understood in the local universe, mostly because the galaxies are bright and close enough to be studied in detail. For galaxies in the peak epoch of star formation, the evolution of the gas fraction is much less well constrained. Measuring the gas content is often done with observations of carbon monoxide, an abundant gas molecule, but in the early universe it is difficult to do because the distances make the lines faint, while the cosmic redshift pushes the usual diagnostic transitions to wavelengths that are beyond the capability of current facilities.

Francesca Civano and a team of her colleagues used the large ALMA millimeter facility to study the gas fractions in a set of forty-five in the cosmic epoch of peak star formation. Although the diagnostic emission lines from the gas were too faint to study, the team used the strong dust continuum as a proxy, arguing from other results that the ratio of gas to dust was reasonably well understood. The gas fractions for this set of galaxies were found to be quite similar to the values in other massive , which was somewhat of a surprise because some evolutionary trends in gas fraction had been expected. Their other important result is that the relationship between the gas fraction and star formation activity is in good agreement with current models and, according to the scientists, implies that a single prescription applies from the local universe out to at least as early as the peak epoch about three billion years ago.


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Citation: Forming stars in the early universe (2016, November 21) retrieved 16 September 2019 from https://phys.org/news/2016-11-stars-early-universe.html
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RNP
Nov 21, 2016
The paper can be found here: https://arxiv.org...10.03656

Nov 21, 2016
The paper can be found here: https://arxiv.org...10.03656

@RNP
thanks!

Nov 21, 2016
Since stars are made from gas, the gas content of galaxies is a measure of their star formation potential and (at least in the local universe) the fraction of matter in form of gas, the "gas fraction", is a measure of the star formation capability.

Astrophysicist's ignorance of plasma knows no bounds, and it goes right down to the fundamental aspects of the matter involved. All their fanciful pontifications of gas dynamics is utterly meaningless drivel not worth the recycled paper its printed on.

Nov 21, 2016
Since stars are made from gas, the gas content of galaxies is a measure of their star formation potential and (at least in the local universe) the fraction of matter in form of gas, the "gas fraction", is a measure of the star formation capability.

Astrophysicist's ignorance of plasma knows no bounds, and it goes right down to the fundamental aspects of the matter involved. All their fanciful pontifications of gas dynamics is utterly meaningless drivel not worth the recycled paper its printed on.


Says the follower of the Velikovskian Invisible Lightning Bolts cult! Those people have more likely forgotten more about plasma than you quite obviously will ever know!

Nov 21, 2016
Astrophysicist's ignorance of plasma knows no bounds
@eu TROLL
except this is proven to be a false statement
repeating this false statement doesn't make it more true
All their fanciful pontifications of gas dynamics is utterly meaningless drivel not worth the recycled paper its printed on
where is your evidence?

if you could prove it you would be holding a nobel
you would at the very least be the hero of every pseudoscience idiot poster here

more to the point: considering you can't accept empirical evidence and experimental validation (like this: http://www.pppl.g...HEET.pdf )

and you can't actually produce the same level of scientific evidence

then why should anyone listen to your rant?

100,000 experiments that prove you wrong in one link
that means, by definition, you're a chronic liar

RNP
Nov 21, 2016
@bschott
Down-voting someone for linking the paper associated with an article is irrational. It also shows that you are not interested in science, only in forwarding your own personal agenda. Although your votes are irrelevant, such behaviour does not belong here.

RNP
Nov 21, 2016
@bschott
It is irrational to down-vote links related to the associated paper, even if the paper WERE irrational (it is not). If you had any interest in REAL science you would appreciate that.

Saying that you have a different (and presumably, in your mind, better) definition of "science" than the people that carry it out just emphasizes the depth of your delusions.

Nov 21, 2016
@full of bs
Not if the paper is irrational
that would require links, references, evidence and the scientific refute
none of which you provided, nor can you provide
You and I define the word "science" differently
perhaps you should try using the dictionary like everyone else?
Downvoting a post equates to pushing my "agenda" does it?
coupled with your other statements and failure to produce evidence, topped off with your known support of pseudoscience, it is considered circumstantial evidence for intent, which is pushing an agenda
You are stump
no, he isn't

and you did downvote a polite reply including the link, which is essentially the same thing

-a nonsensical irrational agenda driven pseudoscience argument sans evidence

kinda like
http://phys.org/n...ted.html

http://phys.org/n...ant.html

RNP
Nov 21, 2016
@bschott
There you go! I knew you would not understand how the rational amongst us perform science.
And then you couldn't help but to prove me right: No actual interest in the science. It's all personal for you isn't it?

Nov 21, 2016
Down-voting someone for linking the paper associated with an article is irrational
@RNP
he hates rational people
especially me... so it doesn't bother me

you should see some of his other irrational claims...like
We have mapped the magnetic fields on the suns surface, this is the first mention of a strapping field, it never existed until it was required for this experiment
http://phys.org/n...ted.html

or this gem
The Martian soil will need to be brought back to earth for study, to determine what colonists will have to add to it in order to make it fertile
http://phys.org/n...oil.html

and as you can see... he doesn't like being proven wrong

ask him about the super-magnetic cancer-killer... you will love that conversation!

Nov 21, 2016
@full of bs
you are shining example of most things wrong with people
like i said - you hate rational people
what is so bad about wanting evidence and not accepting claims that can't be validated as proof of something?
tell me - how many of your super-cancer-killer machine anecdotes have you personally checked and validated to insure they're accurate?
ROTFLMFAO
let me know
..and right back at ya:
Here you go idiot, let me know when you find the word "theoretical" in there somewhere
https://arxiv.org...56v1.pdf

but the article begins with
keyword = "article"
and article is not the same thing as a study
an article is the subjective opinion of the author about a subject - this being the paper that is linked

the study (paper) isn't subjective

this is the root of the problem between us - your acceptance of subjective sources as valid information and objective representations of reality

epic fail

Nov 21, 2016
@full of bs cont'd
And the word "theoretical" does not appear anywhere in the definition of science
which had absolutely nothing to do with my argument...
at all
whatsoever

but lets talk about that a little!

for starters - what is the definition of theory
now what is the definition of a scientific theory

being that you're not clarifying to which you're referring to, how can one actually assign specific definitions to your comment?

by your history

now considering you're past epic failures WRT definitions, basic research and simple facts (like strapping fields, needing martian soil to be brought to earth to know what's in it etc), we can conclude that your intentional vague statements are irrational attempts to apply pseudoscientific logic to your surroundings and argue a point using philosophy rather than through evidenciary proof

therefore you attack with a strawman ""theoretical" does not appear anywhere in the definition of science"

thanks for the demo

Nov 21, 2016
@ bachoot-Skippy. How you are? I am good, thanks for asking.

Ira stated he was an English prof


Where the heck you get that from? I never ever did say I was the English professor or English professional either. I say enough stupid stuffs on my own without you having to make up me saying stupid stuffs I never said..

Nov 21, 2016
@full of bs
I thought
there is absolutely no evidence at all whatsoever that you did this at all - above or elsewhere
you also believe you are relevant and your opinion carries weight
no, i don't
opinions are like *ssholes

lets talk about rational for a moment:
how many people's "claims" on your machine did you validate?
how many of those did you personally visit?
of those, how many medical records did you see?
how many actually had cancer and not a bad diagnosis?
how many of those "cured" can you directly link to your super-machine with evidence?

lastly: how do you know it wasn't a cure because of the MRI, airport security, a metal detector, extension cables in the house, their digital watch and laptops, their wi-fi or any other EM source?
or the MEDS they were prescribed?

a rational person (me) would ask this - as i did
- and you argued against it
there is no doubt about who is "rational" here... and it aint you, little girl

Nov 21, 2016
@full of bs cont'd
The post of mine you responded to when you mentioned that I look up the definition of science
and you think i was arguing that science contained the word "theoretical"?
by all means, show where i state that one! LMFAO

Yet another reading comprehension fail from bschitthead....then again, every post is....

so bschitthead... where is your proof?
where is the proof that i argued about "theoretical"?
(other than your delusional assignment of a reply as justification for a strawman)! LMFAO

where is your proof of your super cancer killer?
martian soil?
strapping fields not existing before the experiment?
the failure of observation of a "strapping field" when you didn't even know what the definition of a strapping field was...????

feel free to expound!
thanks!

LMFAO
.read ALL of the words:
were you going for irony?
LOL

Nov 21, 2016
@ bachoot-Skippy. Well that's better. Apology accepted.

Next time you need use me as the example of somebody saying something stupid, all you got to do is ask first instead of just making something up. That way you can get something that is more like the kind of stupid things I would really say.

Nov 21, 2016
This comment has been removed by a moderator.

Nov 21, 2016
This comment has been removed by a moderator.

Nov 22, 2016
@full of bs
along with completely wrong....just like above with the whole "science" thing
really?
so your claim that my argument is about "theoretical" in science is correct?
then please show my quote!LOL
About the machine
and i call bullsh*t-
1- you can't diagnose stage anything cancer

2- you can't provide empirical evidence that said machine was the cause for *any* healing

3- it's not like EM forces and exposure isn't studied at all - show how the EM works to "heal" or eradicate cancer

4- you can't prove that any other forces or treatment was not the cause of healing

5- claims require evidence: you have never, ever, provided anything proving your super cancer-killer is in any way, shape or form, responsible for curing anything

6- if you can provide a link in the future, at least then you will be substantiating your claim. but that don't mean it's science or even legit - i can post links from people who "prove" faeries live in their yard...

epic fail

Nov 22, 2016
@bschitthead cont'd
go read the thread about the strapping field. You made out far worse than you think
yeah... you keep believing that one
it will help you sleep at night

you claimed strapping fields didn't exist until the experiment - and that they weren't observed - without even actually looking at the definition of the term!

even a quick cursory search of the evidence shows you're an idiot

you got caught in a blatant lie making sh*t up because you want to push your pseudoscience - period
you think a rational person would ask these questions
only you could state that asking pertinent information and requesting evidence that x and y are actually doing what you claim wouldn't be rational...LMFAO

yeah... thanks for outing yourself!

so tell me- why is your magnet machine so much more successful than, say: an MRI?
exposure time?
field strength?
what?
LMFAO

all ya gotta do is provide evidence for your claims
that's it

LOL


Nov 23, 2016
The first stars appeared about one hundred million years after the big bang, and ever since then stars and star formation processes have lit up the cosmos.

The big problem for the researchers is that they are basing their research on the [totally unverified] assumption that stars can form from clouds of gas all by themselves with no outside help whatsoever[too few supernovas to help there either].
So they are making the fraction of gas remaining in a galaxy the measure of the potential of star formation for said galaxy. So what? there's no way to show [currently] that having more gas will necessarily lead to more or faster star formation - all by themselves. That tiny little conundrum of observation still eludes scientists today. All they can really show is that the less gas a galaxy had the more stars are present or vice versa. But not that stars actually form or do not form, depending on gas supply.

RNP
Nov 23, 2016
@FredJose
....So what? there's no way to show [currently] that having more gas will necessarily lead to more or faster star formation


WRONG. Just go and look up the well researched and well documented Kennicutt-Schmidt law.
(e.g. https://en.wikipe...midt_law )

Dec 02, 2016
Maybe someday they will actually learn whether or not stars can form by totally natural processes and even better, if they can, it would be great if they would tell us HOW it happens instead of just telling us THAT it happens. Is that asking too much of a scientist?

http://crev.info/...rmation/

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