Study of distant galaxies challenges the understanding of how stars form

Study of distant galaxies challenges the understanding of how stars form
Credit: ESO/UltraVISTA team. Acknowledgement: TERAPIX/CNRS/INSU/CASU, CC BY-SA

The most massive galaxies in our neighbourhood formed their stars billions of years ago, early in the history of the universe. At the present day, they produce very few new stars. Astronomers have long believed that is because they contain very little gas – a key ingredient necessary to produce stars. But our new study, published in Nature Astronomy, is now challenging this long held view.

Through probing the extreme environments of faraway , we can learn not only about their evolution and the history of the universe, but most importantly about the fundamental processes regulating the formation of . Given that stars produce most of the different types of atoms in our bodies and the world around us, understanding how they were formed is essential if we are to know where we came from.

Galaxies exist in two main types: disc and elliptical. Disc , including the Milky Way, are flat and contain large reservoirs of gas that they use to continually form stars. Elliptical galaxies are massive, round and stopped forming stars long ago. Most theories assume that at some point elliptical galaxies lost their gas reservoirs, which caused the rate of star formation to drop.

Distant light

Our team investigated whether there are other ways in which distant, elliptical galaxies could have lost their ability to form stars. Distance to galaxies are measured by how bright its stars are, in light years (defined as how long it takes the light to reach us in one year). As it takes so long for the light from these faraway galaxies to reach us, we can work out that they appear to us as they were 10 billion years ago.

Study of distant galaxies challenges the understanding of how stars form
Disc galaxy Messier 101. Credit: NASA, ESA, CXC, SSC, and STScI

Ideally we would want to directly observe the gas in these galaxies, but this is extremely challenging and would require several hours of observations per galaxy – and we need to look at thousands of galaxies. Instead, we opted to study dust. Dust (cold rather than hot) only represents 1% of the interstellar matter in a galaxy, but it is found wherever is. A galaxy that contains a lot of dust therefore also contains a lot of gas.

We used data from the Cosmological Evolution Survey (COSMOS), which covers a large patch of the sky observed by most major telescopes, on Earth and in space. We used images from infrared to radio wavelengths of light, which allows us to measure both the rate of star formation and the cold dust mass in galaxies.

Since the galaxies we are interested in are so far away, it is impossible to detect each galaxy individually in the existing infrared or radio data. Instead, we combined the light from 1,000 galaxies and determined how much gas they contain on average and how quickly they are forming stars.

Study of distant galaxies challenges the understanding of how stars form
Elliptical galaxy called ESO 306-17 in the southern sky. Credit: NASA, ESA and Michael West (ESO)

As a result, we made an exciting discovery. Despite having low star formation rates, the elliptical galaxies contain surprisingly large amounts of gas: 100 times more than was expected. This is surprising in two ways. It challenges our standard view of elliptical galaxies as "boring" gas-poor objects. But it also forces us to rethink the basic view of star formation processes – we have always assumed that the presence of cold gas must lead to star formation. Here, we find that elliptical galaxies form stars far less efficiently than disk galaxies at the same epoch.

So why is that? Nine years ago, I predicted this possibility from numerical simulations I had run as a Ph.D. student. I found that in disc galaxies, the gravitational pull of the stars helps the gas to collapse to form . In contrast, the gas in feels a weaker pull from the stars and does not collapse so easily. It is fascinating that the global morphology of a galaxy can control what happens at the smallest scales.

The next steps of our research will use new simulations and hopefully direct observations of the cold gas itself with the Atacama Large Millimeter/submillimeter Array (ALMA), an observatory in Chile, to improve our understanding of the complex interplay between and galaxy morphology. This will shed on universal processes ultimately happening in every galaxy, including our very own Milky Way.

Study of distant galaxies challenges the understanding of how stars form
Star forming nebula, where gas collapses to form new stars. Credit: ESA/NASA/JPL-Caltech

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Jan 19, 2018
Despite having low star formation rates, the elliptical galaxies contain surprisingly large amounts of gas: 100 times more than was expected. This is surprising in two ways. It challenges our standard view of elliptical galaxies as "boring" gas-poor objects. But it also forces us to rethink the basic view of star formation processes – we have always assumed that the presence of cold gas must lead to star formation. Here, we find that elliptical galaxies form stars far less efficiently than disk galaxies at the same epoch.

Surprise! Giant ellipticals (representing the final galactic evolutionary stage) have extremely massive and active grey cores that are ejecting new gas therefrom at an ever increasing rate! The powerful winds then emanating therefrom then disrupt the inner core region where stars might otherwise easily form from the ejected gas. Thus, they become bloated with gas. They need some anti-acid tablets.

Jan 19, 2018
@RNP, Da Schneib, Uncle Ira, and rest of 'gang'.

Are you still in denial after these EXPECTED/PREDICTED (by me) recent astro/cosmo discoveries/reviews by less naive/hack (ie, more informed/objective) mainstream astros/cosmos re 'dust' and other Ordinary 'dark' matter which NOW makes obsolete/unnecessary all those 'Missing Baryons' and "Exotic' DM fantasies which previously proliferated the 'professional model' as a 'fantasy fix' for their previously NAIVE/INCORRECT 'models' (based on woefully incomplete/erroneous data/interpretations due to being ignorant of just how much Ordinary 'stuff' was actually 'out there', everywhere we NOW look with improved/new telescopes/instruments)?

I trust your 'denial' is NOW waning after reading the above/recent, PO articles/reports re FINDINGS of PREVIOUSLY 'dark', yet ORDINARY dust/gas in quantities many times that previously (incorrectly) claimed in old/erroneous BB-etc 'paradigms'!

Cheers, good luck, good thinking, good manners! :)

Jan 19, 2018
@ Really-Skippy. How you are Cher? Still a little bit confused, eh? I am good and could not be any better me, thanks for asking.

@RNP, Da Schneib, Uncle Ira, and rest of 'gang'.

Maybe you should get the doctors to check if they sent you home with the wrong medicines Cher. Not any of those peoples has written a note on this one yet. And I did not do it either, this is my first one.

So far I think the Tux-Skippy is the only one that has chimed in so far, but if you ask him nice, he might be one person that would tell you that you have been correct all along even if nobody else will.

Jan 19, 2018
@ Reality,

Slow down, man-- even at 100X, this still isn't enough additional mass to account for observed gravitational effects.

@Tuxford,

Still no evidence of these " ' extremely massive and active grey cores that are ejecting new gas therefrom at an ever increasing rate!' ".

Nor are elliptical galaxies the " ' final galactic evolutionary stage' ", unless they are the result of serial galactic mergers.

This finding runs somewhat contrary to expectation, but isn't at all surprising, given current observation limitations. Nice that they were able to find a workaround and develop these results, that explain a lot, if they can be rigorously confirmed --which we can probably expect them to be.

RNP
Jan 20, 2018

@RealityCheck
Are you still in denial after these EXPECTED/PREDICTED (by me) .....
I trust your 'denial' is NOW waning after reading the above/recent, PO articles/reports re FINDINGS of PREVIOUSLY 'dark', yet ORDINARY dust/gas in quantities many times that previously (incorrectly) claimed in old/erroneous BB-etc 'paradigms'!

Your overblown impression of yourself is very funny, but let me point out agian that you have not done the maths. The quantities of dust involved are completely insignificant in relation to the *baryonic* mass of the system, let alone the much greater amount of mass attributed to dark matter. The "hidden baryon" discoveries that you so regularly tout as evidence for your silly claim are all the same. They can account for some of the "missing baryons", but are completely insignificant in relation to the mass involved in the DM effect.

Your assertion that sufficient baryonic matter has been detected to account for DM is clearly ridiculous.

Jan 20, 2018
Hi RNP, I hope and trust you and yours are well and having a better New Year than the last. Now to your response:
Your overblown impression of yourself is very funny, but let me point out agian that you have not done the maths. The quantities of dust involved are completely insignificant in relation to the *baryonic* mass of the system, let alone the much greater amount of mass attributed to dark matter. The "hidden baryon" discoveries that you so regularly tout as evidence for your silly claim are all the same. They can account for some of the "missing baryons", but are completely insignificant in relation to the mass involved in the DM effect.

Your assertion that sufficient baryonic matter has been detected to account for DM is clearly ridiculous.
Oh, but I HAVE DONE the maths; but you all REFUSE to do so and/or ignore the crucial fact EACH dust/pebble has MANY hundreds/millions/billions MORE 'Baryonic nuclei' MASS than Hydrogen/Helium gas nuclei. Do the maths. :)

Jan 20, 2018
Hi Uncle Ira, good to hear you are well.
@ Really-Skippy. How you are Cher? Still a little bit confused, eh? I am good and could not be any better me, thanks for asking.

@RNP, Da Schneib, Uncle Ira, and rest of 'gang'.

Maybe you should get the doctors to check if they sent you home with the wrong medicines Cher. Not any of those peoples has written a note on this one yet. And I did not do it either, this is my first one.

So far I think the Tux-Skippy is the only one that has chimed in so far, but if you ask him nice, he might be one person that would tell you that you have been correct all along even if nobody else will.
This "exotic' DM issue has been the subject of a longstanding 'conversation' between me and those I alluded to in my first post above; hence the 'denial' alluded to was also a longstanding issue harking back to many more PO articles/discussions than the present one above.

Good luck, good thinking, and good manners, Ira; stay well. :)

Jan 20, 2018
Hi Caliban, I trust you and yours are well, and remain so for this New Year (and beyond). Re your response:
--even at 100X, this still isn't enough additional mass to account for observed gravitational effects.
I remind of my longstanding 'tip of iceberg' predictions re what Normal Matter was previously 'seen/estimated' and what was actually 'out there' (previously 'unseen/in fact'). Now a string of discoveries/reviews by mainstream astros/cosmos with new/improved instruments/telescopes, points irrefutably to MANY TIMES NORMAL matter than previously estimated; which increasingly refutes all 'exotic' DM etc hypotheses/claims. Eg, we've found:

- Galaxies near and far are many times more extensive/massive than previously/erroneously 'believed';

- observable universe 'everywhere' contains MUCH MORE DUST/PEBBLE matter than previously 'believed'; which itself points to many times MORE 'gas' as well than previously 'believed'.

Do the math again, including all that, mate. :)

RNP
Jan 21, 2018
@RealityCheck
Oh, but I HAVE DONE the maths;.....


OK, then . Prove it! Show us some studies and how you have arrived at the conclusion that they constitute a significant contribution to DM.

I know that you won't, because I know that you can't, and that, as usual, you LIE when you say you have "done the maths".

Jan 21, 2018
i recently read a study saying that, to account for the amount of light in any patch of sky, there must be a significant number of extra galactic stars and the rate at which we see gravitationally unattached stars zooming through our galaxy supports this idea.

Jan 21, 2018
@RNP.
OK, then . Prove it! Show us some studies and how you have arrived at the conclusion that they constitute a significant contribution to DM...
What will it take, mate; to disabuse yourself of all those beliefs and biases inculcated in you by old/obsolete/erroneous hypotheses and interpretations based on nothing more than naive/incorrect data/modeling from early BB etc fantasies treated as 'fact' for so long despite there being NO objective scientifically/logically TENABLE evidence in support!

As for 'doing the math' and 'logical thinking' based on REAL things/data (as opposed to what has been happening in 'professional' theoretical physics and cosmology for decades now----just ask Penrose and Steinhardt etc)---I HAVE.

For YEARS I've been pointing out ALL YOU NEED to do the maths and logical thinking FOR YOURSELVES; but you STILL ignore, disparage, deny!

The 'egg on face' from BB/Bicep2 etc 'believers' fiascoes should've taught you to STOP, LISTEN and THINK. :)

RNP
Jan 22, 2018
@RealityCheck
So, as predicted, you are unable to provide ANY evidence for your silly claims and you make plain your blatant lie about "having done the maths". You are a contemptible troll and I will waste no more time on you.

Jan 22, 2018
@idiot sam fodera the proven pseudoscience cult regurgitator of lies
What will it take, mate; to disabuse yourself of all those beliefs and biases
he actually answered this above... you know, where he stated
OK, then . Prove it! Show us some studies and how you have arrived at the conclusion that they constitute a significant contribution to DM
of course, like a consummate professional scientist, he also makes a prediction:
I know that you won't, because I know that you can't
which you validated

LOL
The 'egg on face' from BB/Bicep2 etc
let me finish that for you:
the egg is still on your own face for lying and posting 7,635 times without evidence which you still can't seem to find or link to prove yourself (accurate as of January 21, 2018, 3:23 pm)

it doesn't matter *that* BICEP was wrong, but that you claimed to see "fatal flaws" in a free study which you still can't actually point to despite the historical disassembly by physicists

reported

Jan 22, 2018
I just had a quick squint at the (paywalled) paper:
https://www.natur...7-0352-5

First off, this excess dust/gas is only seen in the more distant (i.e. younger) Early-type galaxies. It cannot be used to define all ETGs.
Secondly, it cannot be used universally for all other types of galaxies.
Thirdly, the authors say:
"The large amount of dust we detect, and the inferred gas mass, imply that high-redshift ETGs are remarkably gas rich, with up to 11% of their baryonic mass being in the form of gas."
As for the dust, they estimate that there is ~ 2 oom more than in the local ETGs.

So, somebody else can do the maths, but my first look says that the excess isn't even close to helping with the 'missing' baryonic matter.

Jan 22, 2018
Whoops^^^^^

Another point would be that if these younger ETGs have a higher dust/ gas mass than the older ETGs, then that dust/ gas has gone somewhere. Into making stars would be my guess.

Jan 22, 2018
@RNP.
You are a contemptible troll and I will waste no more time on you.
You're not listening! You persist with old biases, malicious lies-in-denial, RNP. It's as if you swallowed Captain Stumpy's 'Cool Aid" in one gulp! If you can just get out from under that self-imposed ignorance of what has been going down in my posts (and mainstream discovery/review of late years and even as we speak), you will 'see' the maths/logics! Seriously, mate, it's as if your ego/biases, beliefs, overrule your intellectual objectivity; turning you into a 'nasty religious believer' instead of true scientist. Haven't you kept up with mainstream discoveries? Eg:

- Deep space is so cold that much of the 'gases' form Super-fluidic/conducting 'boson-like condensates' which transmit EM wavelengths;

- Deep space is REPLETE with PREVIOUSLY 'unseen' dust/gases!

RNP, please, for your OWN (and science's) sake: READ UP; STOP doing/being 'a stumpy' (ie: a biased ignorant malicious lying troll)! :)

Jan 22, 2018
Hi jonesdave, thanks for your polite response; and I hope you are having a safe and healthy new year.
I just had a quick squint at the (paywalled) paper:
https://www.natur...7-0352-5

First off, this excess dust/gas is only seen in the more distant (i.e. younger) Early-type galaxies. It cannot be used to define all ETGs.
I will again point out that the recent 'string of discoveries' should be considered in toto; then 'connect' ALL the 'dots' (see also my previous posts mentioning some recent realizations in cosmology field re MUCH MORE Ordinary Matter in 'space' and MUCH GREATER 'galaxy' mass/content/extent).

This particular instance is but a 'tip of iceberg' indicator of extensively more gas and dust 'out there'.

This article/paper even gives passing reference to 'tip of iceberg' ORDINARY MATTER reality when analyzing/making 'observations/estimates' matter.

So please try to read/connect ALL the 'dots'; and look BEYOND 'tip of iceberg', mate. :)

Jan 22, 2018
This particular instance is but a 'tip of iceberg' indicator of extensively more gas and dust 'out there'.


And the evidence for that is? That is, that it can account for ~ 24x the observed baryonic matter?

This article/paper even gives passing reference to 'tip of iceberg' ORDINARY MATTER reality when analyzing/making 'observations/estimates' matter.


I didn't see that inference in the paper. Another paper from the same group found lower than expected dust ratios in galaxies at z = 5 - 6.
https://arxiv.org...2980.pdf

So please try to read/connect ALL the 'dots'; and look BEYOND 'tip of iceberg', mate. :)


I am. I read their paper, and have looked at others from similar surveys. I don't see any way of reconciling this dust/ gas with the necessary 'missing' baryonic matter. And I am sure the authors of those papers would be busting a gut if they saw any such correlation, because a trip to Stockholm would be pretty much guaranteed.


Jan 22, 2018
I will again point out that the recent 'string of discoveries' should be considered in toto; then 'connect' ALL the 'dots' (see also my previous posts mentioning some recent realizations in cosmology field re MUCH MORE Ordinary Matter in 'space' and MUCH GREATER 'galaxy' mass/content/extent).


What? You mean you don't know? You don't know that all they're discovering is MORE of what they ALREADY knew was there? Right Jonesy? Rguy?

Of course in the first place they never expected to find all that baryonic dust along the filaments extending between galaxies, nope, they expected to find ONLY their precious DM cosmic fairy dust, but that's okay, there's room for everything even there's becoming less & less of it available into which to squeeze all that 80% missing mass cosmic fairy dust.


Jan 22, 2018
Of course in the first place they never expected to find all that baryonic dust along the filaments extending between galaxies, nope, they expected to find ONLY their precious DM cosmic fairy dust...


Errr..

In cold dark matter cosmology, the initially smooth distribution of matter in the Universe is expected to collapse into a complex network of filaments and voids, structures which have been termed the 'cosmic web'. The filamentary distribution of galaxies in the nearby Universe has been revealed in detail by recent large galaxy redshift surveys such as the Two-degree Field Galaxy Redshift Survey (2dFGRS), the Sloan Digital Sky Survey and the Two-Micron All-Sky Survey Numerical simulations successfully reproduce this network and indicate that galaxies are only the tip of the iceberg in this cosmic web


https://academic..../1016998

Jan 22, 2018
I'll predict right now what will ultimately be the death of the Dark Matter fairy tale. The James Webb Telescope.

When that infrared spectroscopy starts coming in from the farthest reaches of the visible universe, many more fairy tales that cosmologists have proffered up will become nakedly impossible to defend. Very silently we will hear a deafening muting of discussions about cosmic fairy dust, that will also extend into the anti-Entropy debate of Dark Energy as well.

Science is fun, it exposes who the neophytes are compared to who are real world people.


Jan 22, 2018
I'll predict right now what will ultimately be the death of the Dark Matter fairy tale. The James Webb Telescope.


And I'll predict that it won't. Telescopes of various flavours have improved hugely since DM was first proposed. All the observations have continued to show that it must be there.

A DIRECT EMPIRICAL PROOF OF THE EXISTENCE OF DARK MATTER
https://arxiv.org...0608407/

A filament of dark matter between two clusters of galaxies
https://arxiv.org...0809.pdf

RNP
Jan 23, 2018
@Benni
Science is fun, it exposes who the neophytes are compared to who are real world people.

My word! You have said something that I agree with. I thought the day would never come! I look forward to seeing who the "neophytes" are very much. N.B. I have bookmarked this thread for future reference.

Jan 23, 2018
@benji the troll
Science is fun, it exposes who the neophytes are compared to who are real world people.
epic irony is epic

more wisdom from benji:
I don't even know what it is you & WG are even talking about, something about ODE whatever that is?
http://phys.org/n...ood.html]http://phys.org/n...ood.html[/url]

the wobble cycle of Earth's rotational axis seems to correlate closely with the time required for our solar system to complete a full orbital passage around the galactic core of the Milky Way
http://phys.org/n...als.html

more math fails:
http://phys.org/n...ood.html]http://phys.org/n...ood.html[/url]

http://phys.org/n...s_1.html

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

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

and this excludes his plagiarism or engineering fails

.

just epic!

Jan 23, 2018
Hi jonesdave.
That is, that it can account for ~ 24x the observed baryonic matter?
Did you mean to write 5x instead of 24x? Ordinary matter previously observed/estimated to account for approx 20% of the overall 'needed' gravitating matter; hypothesized 'Exotic' DM allegedly forming the other 80%; altogether making 5x what was previously observed, yes?
I didn't see that inference in the paper.
The above article implies it clearly...
A galaxy that contains a lot of dust therefore also contains a lot of gas.
...and that implication is itself a 'tip of iceberg' acknowledgement for what is still not seen 'all over', as gas, dust, pebbles, etc.
Another paper from the same group found lower than expected dust ratios in galaxies at z = 5 - 6.
Your linked paper/study treats ONLY expected dust MIXED with STARS WITHIN said galaxies; it says nothing about all that dust/gas we NOW KNOW extends MUCH further out from galaxies (now SEEN to be BIGGER, more Massive).

cont

Jan 23, 2018
cont

@jonesdave.
So please try to read/connect ALL the 'dots'; and look BEYOND 'tip of iceberg', mate.
I am. I read their paper, and have looked at others from similar surveys. I don't see any way of reconciling this dust/ gas with the necessary 'missing' baryonic matter. And I am sure the authors of those papers would be busting a gut if they saw any such correlation, because a trip to Stockholm would be pretty much guaranteed.
As Bicep2 'wishful', 'self-deluding', tendencies showed, assumptive/personal 'blinkes' are powerful and ubiquitous in the field (as Penrose and Steinhardt admitted). It's taken decades to get THEM to take THEIR 'blinkers' off; and apparently it's going to take a little more time (and new-dots-under-their-noses) to shock hack 'paper-writers' to even begin to start actually 'connecting' ALL the dots mainstream itself is providing but not yet CONSOLIDATING. So they're late to the 'connect the dots' party (to which I arrived first, it seems).

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