Galaxies without stars: The problem of the missing hydrogen in the early Universe

Nov 09, 2012
A black hole quasar. Credit: NASA

(Phys.org)—Hydrogen is the most common element in the Universe, making up 75% of all normal matter and the content of stars. Although stars themselves are hot, they can only form out of the coldest gas when a massive cloud of hydrogen can collapse under its own gravity until nuclear fusion starts – the fusing of atoms together which releases the huge amounts of energy we see as starlight.

Astronomers have been puzzled as to why they could not detect this cold star-forming gas in the most distant, and hence older, regions of the Universe. At such vast look-back times, astronomers expected the gas to be much more abundant as it has yet to be consumed by .

Dr Stephen Curran, from the University of Sydney's School of Physics and CAASTRO – the ARC Centre for All-sky – and Dr Matthew Whiting, from CSIRO Astronomy and , have addressed this problem by devising a model that shows how the , lurking within the centre of each active galaxy, is able to ionise all of the surrounding gas even in the very largest galaxies.

When is in this state, where the electron is ripped out of the atom, the gas it too agitated to allow the cloud to collapse and form stars. Also, when ionised, it cannot be detected through at 21-centimetres – the way cold star-forming gas is normally found.

"Previously, we had not known just how much of the gas was ionised by the black hole accretions disks – we had thought that perhaps it was just enough to take the abundance of cool gas to below the detection threshold of current . So we'd thought that it was maybe a telescope sensitivity issue," said Dr Curran.

Dr Curran and Dr Whiting's latest research, published in The on 10 November 2012, shows that the extreme ultra-violet radiation given off by the material being sucked in – at near light-speeds – to the black hole, is sufficient to ionise all of the gas in even the very largest galaxies.

"In order to probe further back in time, we choose the most distant radio sources. What appears as faint light from these, to us on Earth, is actually extreme ultra-violet, dimmed and stretched (redshifted) to visible light on its several billion year journey to us," explained Dr Curran.

"Unfortunately, these are the only objects we know of at the very limits of the cosmos and within these the radiation from the central black hole is so intense as to heat all the gas to the point where it cannot form stars.

"We have shown that rather than being a telescope sensitivity issue, all of the billions of suns worth of gas is indeed ionised. This means that even the Square Kilometre Array – the biggest radio telescope, which is currently being built in Australia, New Zealand and southern Africa – will not be able to detect star-forming gas in these galaxies," said Dr Curran.

"The Square Kilometre Array will excel, however, in detecting very cold gas that is too faint to be detected by optical telescopes, which must have existed to give us the stars and galaxies we see today."

Explore further: Image: Chandra's view of the Tycho Supernova remnant

Related Stories

Image: Black hole caught in a stellar homicide

Jul 12, 2012

(Phys.org) -- This computer-simulated image shows gas from a star that is ripped apart by tidal forces as it falls into a black hole. Some of the gas also is being ejected at high speeds into space.

Dwarf galaxy has giant surprise

Jan 12, 2005

Huge gas disk may be similar to stuff of early universe An astronomer studying small irregular galaxies has discovered a remarkable feature in one of them that may provide key clues to understanding how galaxies form and ...

Do black holes help stars form?

Feb 03, 2012

(PhysOrg.com) -- The center of just about every galaxy is thought to host a black hole, some with masses of thousands of millions of Suns and consequently strong gravitational pulls that disrupt material around ...

Recommended for you

Image: Chandra's view of the Tycho Supernova remnant

19 hours ago

More than four centuries after Danish astronomer Tycho Brahe first observed the supernova that bears his name, the supernova remnant it created is now a bright source of X-rays. The supersonic expansion of ...

Satellite galaxies put astronomers in a spin

Jul 24, 2014

An international team of researchers, led by astronomers at the Observatoire Astronomique de Strasbourg (CNRS/Université de Strasbourg), has studied 380 galaxies and shown that their small satellite galaxies almost always ...

Video: The diversity of habitable zones and the planets

Jul 24, 2014

The field of exoplanets has rapidly expanded from the exclusivity of exoplanet detection to include exoplanet characterization. A key step towards this characterization is the determination of which planets occupy the Habitable ...

User comments : 57

Adjust slider to filter visible comments by rank

Display comments: newest first

tadchem
1.8 / 5 (8) Nov 09, 2012
Is there a proposed mechanism by which the plasma that has been ionized by supermassive black holes (and presumably is continuously so) can nonetheless cool sufficiently over time to permit star formation?
An alternative hypothesis is that hydrogen atoms can occur in states that are described by principle quantum numbers (N) that are rational numbers less than unity. The electron wave function is not static, but rather repeats periodically.
These states are electromagnetically inert with transitions available only through inelastic collisions (delta L = 0).
cantdrive85
1 / 5 (16) Nov 09, 2012
There is no limit to the wonders this enigmatic monster can accomplish. Now it's responsible for ionizing the Universe. Being that 99.99% of the visible universe is plasma, those BH's have certainly been busy.

kenny1951
1.7 / 5 (3) Nov 09, 2012
Dark Energy anyone ?
Torbjorn_Larsson_OM
4.8 / 5 (15) Nov 09, 2012
A puzzle within an enigma.

@ tadchem: Rational quantum numbers are characteristics of collective quantum phenomena, most often in solids. When you hear hoof beats, think horses, not zebras. And indeed we see nothing of that in astronomy today.

@ cantdrive85: BHs are well known, oft studied common phenomena. 100 % of the universe is ruled by gravity, and BHs are part of that. Plasma effects are observably secondary on general relativity cosmology.

@ kenny1951: No one for dark energy. It is a very weak energy, and was overwhelmed by radiation pressure and later matter in the early universe. That is why dark energy caused expansion is significant only in the late universe.

These early effects can be caused by anything except dark energy. [ http://en.wikiped...ated_era ]
PosterusNeticus
5 / 5 (8) Nov 09, 2012
Is there a proposed mechanism by which the plasma that has been ionized by supermassive black holes (and presumably is continuously so) can nonetheless cool sufficiently over time to permit star formation?
An alternative hypothesis


I don't see that an alternative hypothesis is necessary. If the massive, initial accretion disk is the source of radiation ionizing the gas, then as the disk is consumed by the black hole the radiation should naturally decrease over time; the gas cools, stars form.
cantdrive85
1 / 5 (19) Nov 09, 2012
Tor, you're tripping over your dogma again, careful not to break it's tail.
radek
1 / 5 (4) Nov 09, 2012
If there were only hydrogen and helium in early Universe and they were too hot to collapse how those BH were created?
boater805
1.2 / 5 (6) Nov 09, 2012
Is there a proposed mechanism by which the plasma that has been ionized by supermassive black holes (and presumably is continuously so) can nonetheless cool sufficiently over time to permit star formation?


The ionized hydrogen is a plasma and can not condense to form stars under the force of GRAVITY! However, plasmas can generate immense complex magnetic fields to which ionic hydrogen is coupled far more strongly than gravitational influences. Perhaps the problem IS the solution?

Pressure2
1 / 5 (1) Nov 09, 2012
If there were only hydrogen and helium in early Universe and they were too hot to collapse how those BH were created?

Very good question!
boater805
1 / 5 (3) Nov 09, 2012
that which you do not see here was withdrawn
PosterusNeticus
4.7 / 5 (10) Nov 09, 2012
If there were only hydrogen and helium in early Universe and they were too hot to collapse how those BH were created?


You're getting the order of operations mixed up. The black hole gorges on the gas of the young galaxy; you have a massive accretion disk and a quasar. Between them you have a massive outpouring of radiation. But the black hole doesn't have infinite reach, and eventually it consumes the gas around it. The feeding frenzy dies down, and with it the radiation. The remaining gas, no longer bombarded by that radiation, cools, allowing star formation.

In other words it's not too hot to form the black hole. Rather, the black hole forms and temporarily suppresses star formation.
Pressure2
1 / 5 (11) Nov 09, 2012
If there were only hydrogen and helium in early Universe and they were too hot to collapse how those BH were created?


You're getting the order of operations mixed up. The black hole gorges on the gas of the young galaxy; you have a massive accretion disk and a quasar. Between them you have a massive outpouring of radiation. But the black hole doesn't have infinite reach, and eventually it consumes the gas around it. The feeding frenzy dies down, and with it the radiation. The remaining gas, no longer bombarded by that radiation, cools, allowing star formation.

In other words it's not too hot to form the black hole. Rather, the black hole forms and temporarily suppresses star formation.

Double talk!
PosterusNeticus
4.5 / 5 (8) Nov 09, 2012
If there were only hydrogen and helium in early Universe and they were too hot to collapse how those BH were created?


You're getting the order of operations mixed up. The black hole gorges on the gas of the young galaxy; you have a massive accretion disk and a quasar. Between them you have a massive outpouring of radiation. But the black hole doesn't have infinite reach, and eventually it consumes the gas around it. The feeding frenzy dies down, and with it the radiation. The remaining gas, no longer bombarded by that radiation, cools, allowing star formation.

In other words it's not too hot to form the black hole. Rather, the black hole forms and temporarily suppresses star formation.

Double talk!


How? How is that "double talk"? It's not "double talk", it's simple logic. It's the radiation from the vicinity of the black hole that ionizes the gas. Nothing prevents the black hole from forming in the first place.
Pressure2
1 / 5 (10) Nov 09, 2012
Nothing but they originate from extra large supernova type stars. So if the stars have a problem forming how could a BH form?
PosterusNeticus
4.6 / 5 (9) Nov 09, 2012
Nothing but they originate from extra large supernova type stars. So if the stars have a problem forming how could a BH form?


You're still not getting that it's the black hole that suppresses star formation. That first generation of stars is free to form and die and collapse and merge into the supermassive black hole because there is no supermassive black hole there yet.

Draw yourself a timeline if you can't work it out in your head.
Pressure2
1 / 5 (9) Nov 09, 2012
You appear to be the one not getting it. It is the lack of cold hydrogen that make star formation difficult if not impossible.
Star formation must occur BEFORE you have the BH's your idea rest upon.
PosterusNeticus
4.6 / 5 (9) Nov 09, 2012
It is the lack of cold hydrogen that make star formation difficult if not impossible.
Star formation must occur BEFORE you have the BH's


Are you trolling me or are you really this dense?

It's the radiation from the vicinity of the black hole that suppresses star formation. The first generation of stars that FORMS that black hole is not prevented from forming, because they have not yet formed the black hole that will ionize the gas later on.

Honestly I'm beginning to think you're just trolling me. It's not that difficult to understand. The stars that form the black hole are not impeded because there is nothing ionizing the gas yet. WHEN that first generation of stars forms the black hole, THEN the radiation ionizes the gas and suppresses star formation.

I'm sorry but I can't make it any simpler for you. And it's not "my idea". Go read the bloody paper instead of making up nonsense.

Pressure2
1 / 5 (9) Nov 09, 2012
Hey, the hydrogen gas IS ionized after the BB. The universe is HOT and dense during this time period. That is what this article is about, where is the COLD hydrogen gas to form the FIRST stars. Forget your BH, they haven't even formed yet. Period.
PosterusNeticus
5 / 5 (9) Nov 09, 2012
Hey, the hydrogen gas IS ionized after the BB. The universe is HOT and dense during this time period. That is what this article is about, where is the COLD hydrogen gas to form the FIRST stars. Forget your BH, they haven't even formed yet. Period.


Now I know you didn't even read the article, never mind the paper. No wonder you're so confused :)

I don't know why you're trying to squeeze these events into the moments after the Big Bang, but that's the wrong point on the timeline. That's where you're going wrong. Well, that's part of how you're going wrong, anyway.

The gas has already cooled, already condensed into the clumps that will eventually become galaxies. This is not shortly after the big bang. This is later. The first generation(s) of stars forms from this gas. The black hole forms.

Now, you can read the article, read the paper, and sketch out a timeline for yourself like I said. Or you can continue to make up nonsense. Your call. As it stands your posts are gibberish.
PosterusNeticus
5 / 5 (8) Nov 09, 2012
Look, the critical point you need to understand -- the point you keep tripping yourself over -- is that recombination from the BB has already occurred. We're past that. This article is talking about the evolution of a galaxy. The ionization caused by the quasar is local, not universal.
Pressure2
1 / 5 (9) Nov 09, 2012
You seem to have overlooked the quote below.

Quote from article: "Astronomers have been puzzled as to why they could not detect this cold star-forming gas in the most distant, and hence older, regions of the Universe."
PosterusNeticus
5 / 5 (9) Nov 09, 2012
Read the post right above your last. Recombination from the BB has already occurred. Read the article again. It's about black holes suppressing star formation. That comes later. Never mind what you choose to make up in your head. Just read what it actually says.

If you refuse to do even that much, or if you truly cannot understand this, then I cannot help you.
ValeriaT
1 / 5 (13) Nov 09, 2012
The lack of hydrogen (and lithium and other lightweight elements) is not the only problem of the Big Bang model. The ancient galaxies are of high metallicity and they do contain the heavy elements, which could be formed just during repeated explosions of supernovas in many stelar generations, which wouldn't get time for their formation in most distant areas of Universe. A steady state model will be a much more natural explanation here. AWT explains the red shift with dispersion of light at the density fluctuations and it predicts, that the expansion of Universe is as observed with visible light by the red shift will be balanced with blue shift in radiowave spectrum. In this sense, our Universe actually doesn't expand, it just appears so: the galaxies are forming from dark matter and evaporating into it continuously all around us like the giant fluctuations of dense gas, which we are formed by.
PosterusNeticus
5 / 5 (10) Nov 09, 2012
Oh, good. The cold fusion/steady state/conspiracy wingnuts are chiming in now. Have fun, I'm out.
Pressure2
1 / 5 (10) Nov 09, 2012
PN, what does it have to do with ionized gases? It has to do with the temperature of the hydrogen gases. Where are the COLD hydrogen gas pockets it the early universe needed to from the first stars?
PosterusNeticus
5 / 5 (9) Nov 09, 2012
Where are the COLD hydrogen gas pockets it the early universe needed to from the first stars?


Answer: EVERYWHERE, because this period being discussed is long after recombination and cooling after the Big Bang. As I keep trying to explain to you, the period this paper is looking at is after the universe has calmed down enough for star formation to occur. Galaxies are forming, right? Right. So this is not the hot, chaotic soup from right after the BB. It's later on.

Forget the casual, imprecise, sloppy language that the article's author used. Read the paper instead.
ValeriaT
1 / 5 (9) Nov 09, 2012
When hydrogen gas is in this state, where the electron is ripped out of the atom, the gas it too agitated to allow the cloud to collapse and form stars. Also, when ionised, it cannot be detected through radio waves at 21-centimetres – the way cold star-forming gas is normally found.
This theory still faces a problem, because in this case the first galaxies couldn't be formed at all. If we are observing them, it just means the stars are already formed there, which means all that hydrogen couldn't be ionized and we should observe it. Whole this theory is a nonsense anyway, because the hydrogen must be cooled first before forming the first black holes and it was formed in diluted state in accordance to Big Bang model, so it should cool and collapse fast.
omatwankr
1 / 5 (9) Nov 09, 2012
"after the universe has calmed down enough for star formation to occur."

From article
"At such vast look-back times, astronomers expected the gas to be much more abundant as it has yet to be consumed by star formation."

dante_danthony
1 / 5 (5) Nov 09, 2012
Dark Energy anyone ?
My first thought too.
Job001
1 / 5 (4) Nov 09, 2012
Oh, good. The cold fusion/steady state/conspiracy wingnuts are chiming in now. Have fun, I'm out.

Well now, let's not join the wing nuts, cold fusion has been replaced with LENR which reportedly by many experts yields more power than hot fusion but LENR research is only 5 years old vs 50 for hot fusion and the field is justifiably contaminated by promoters since mainstream physicists maybe justifiably afraid of unemployment. I'm not a believer nor non-believer but one can brush up on the status of LENR at LENRProof.com very well put together by an intelligent soul.

I read the article about how a large black hole may ionize the hydrogen. With the many recent discoveries of WIMPS and HIGGS boson, and the now abundant black holes theories. I'm skeptical this one explanation is satisfactory. The hydrogen could be relativistic or bound by subatomic particles or in lower ground states(If such a thing becomes proven or accepted) or other spectroscopically undetectable states.
dante_danthony
1 / 5 (5) Nov 09, 2012
When hydrogen gas is in this state, where the electron is ripped out of the atom, the gas it too agitated to allow the cloud to collapse and form stars. Also, when ionised, it cannot be detected through radio waves at 21-centimetres – the way cold star-forming gas is normally found.
This theory still faces a problem, because in this case the first galaxies couldn't be formed at all. If we are observing them, it just means the stars are already formed there, which means all that hydrogen couldn't be ionized and we should observe it. Whole this theory is a nonsense anyway, because the hydrogen must be cooled first before forming the first black holes and it was formed in diluted state in accordance to Big Bang model, so it should cool and collapse fast.

Boom! He slaps them....but, but-how much do we really know about early universe black hole formation? De nada. There really isn't any reason to believe black holes in the early universe formed the same way they do now.
vidyunmaya
1 / 5 (9) Nov 10, 2012
Sub: Cosmology -Origins
Cosmology needs best of brains trust. Cosmology Definition is presented by me after in-depth study- Cosmology vedas Interlinks.
What is strange -a dogma or enigma - stagnant mode -that too among cosmologists -is an unfortunate intellectual Hollowed spirit.
cantdrive85
1 / 5 (14) Nov 10, 2012
"When hydrogen gas is in this state, where the electron is ripped out of the atom, the gas it too agitated to allow the cloud to collapse and form stars. Also, when ionised, it cannot be detected through radio waves at 21-centimetres – the way cold star-forming gas is normally found."

There is no hope for these "scientists" to have a clear understanding of anything in space now let alone billions of years ago with such a perverse and inaccurate understanding of plasma behavior. Scientists make the very questionable ASSUMPTION that the natural state of matter is gas, liquid, or solid, being that 99.99% of the Universe is currently in the plasma state, observation should be a reasonable indication that plasma is the natural state until it cools in very specific locales. According to A. Peratt the ONLY places in the Universe where you can expect to find states of matter other than plasma is in the near crustal regions of planets like our own, plasma IS the fundamental state of matter.
Shinichi D_
4.4 / 5 (5) Nov 10, 2012
Nothing but they originate from extra large supernova type stars. So if the stars have a problem forming how could a BH form?


No stars are needed to form black holes. Supermassive and quantum black holes form without stars. They don't even need atoms. Black holes can form out of plasma or even the primordial quantum soup.
ValeriaT
1 / 5 (9) Nov 10, 2012
There really isn't any reason to believe black holes in the early universe formed the same way they do now.
It of course isn't - but it would be just another layer of epicycles added in an effort to save the model, which would remain dysfunctional otherwise. We already introduced the inflation, dark matter and dark energy in the Big Bang model in the same ad-hoced way and its conceptual problems persist. This is not what the scientific theories are supposed to: they should spare us of logical inconsistencies - not to generate them.

Unfortunately the mainstream physics is driven with different criterions than with Occam's razor and with effectiveness of approach. Such a theories are beloved in quiet, because they bring an opportunity of new jobs without urgent need to change of basic paradigm of thinking. Does the Big Bang theory require the quintessence or some other particle for being able to work? Brilliant: we can start with building of detectors and asking money for it!
Pressure2
1 / 5 (6) Nov 10, 2012
The quote from the article below refutes everything PN has posted about this article so far. He can keep giving people 1's but that doesn't change the facts. He's got his cart before his horses.

"after the universe has calmed down enough for star formation to occur."

From article
"At such vast look-back times, astronomers expected the gas to be much more abundant as it has yet to be consumed by star formation."


Pressure2
1 / 5 (6) Nov 10, 2012
Nothing but they originate from extra large supernova type stars. So if the stars have a problem forming how could a BH form?


No stars are needed to form black holes. Supermassive and quantum black holes form without stars. They don't even need atoms. Black holes can form out of plasma or even the primordial quantum soup.

Please don't introduce more magic into astronomy than there already is. What we need is more facts.
ValeriaT
1 / 5 (4) Nov 10, 2012
But he's actually quite correct. In AWT the galaxies are evaporating into photons and neutrinos which condense somewhere else like the giant fluctuations of dense gas. The final stages of this transition are always photons and neutrinos, so that the quasars are formed from cloud of dark matter: essentially from nothing in similar way, like the Universe in accordance to Big bang model. This model explains, why we can observe the quasars and "black holes" without hydrogen at all. Compare the "gravastar" or "dark energy stars" of some other astronomers.
Shinichi D_
4.1 / 5 (7) Nov 10, 2012
Nothing but they originate from extra large supernova type stars. So if the stars have a problem forming how could a BH form?


No stars are needed to form black holes. Supermassive and quantum black holes form without stars. They don't even need atoms. Black holes can form out of plasma or even the primordial quantum soup.

Please don't introduce more magic into astronomy than there already is. What we need is more facts.


No magic. Primordial black holes were predicted by BB. It' obvious that your knowledge is very limited, and you just make it worse by denial.
Only stellar black holes need progenitor stars.
ValeriaT
1 / 5 (3) Nov 10, 2012
Primordial black holes were predicted by BB
Yes, but these black holes are assumed to be of mass comparable to asteroids and they're supposed to be very tiny in general. They shouldn't swallow the dark matter, they're supposed to form the dark matter instead.
Pressure2
1 / 5 (6) Nov 10, 2012
So primordial BH are predicted (needed is more like it) in the BB theory? Just because they are needed to explain early star formation does not mean they have not introduced "magic" into the BB theory. The inflationary period is another magical period introduced to explain why the universe is flat.
Q-Star
3.5 / 5 (8) Nov 10, 2012
Oh, good. The cold fusion/steady state/conspiracy wingnuts are chiming in now. Have fun, I'm out.


Shouldn't that been: cold fusion/steady state/flat earth/plasma cosmological/electric universe/alien pulsar radio beacon/Templar treasure wingnuts?
Q-Star
2.8 / 5 (5) Nov 10, 2012
Cosmology needs best of brains trust.


I bet you are thinking you might fit the bill?

presented by me after in-depth study- Cosmology vedas Interlinks.


That's what I thought you were going to say.
radek
1 / 5 (6) Nov 10, 2012

No magic. Primordial black holes were predicted by BB. It' obvious that your knowledge is very limited, and you just make it worse by denial.
Only stellar black holes need progenitor stars.


there`s no proof for such BH it`s only theory. More - if density of early Universe was so extreme to create such BH why all Universe didn`t colapse into one BIG BH? Universe was homogenous at the begining.
ValeriaT
1 / 5 (6) Nov 10, 2012
So primordial BH are predicted (needed is more like it) in the BB theory?
The Big Bang model is rather "flexible" in this matter. Originally, when CMBR fluctuations weren't observed the Universe was believed to be very flat, so that the inflationary model was proposed to make the Big Bang sufficiently "smooth". In such a model only very tiny black holes (if any) could be formed. Later the dark matter has been found and the density fluctuations of CMBR were revealed with COBE/WMAP spaceprobes, so that the inflation model was "adjusted" with another and another terms for to make it no so smooth. In this "chaotic inflation" model even larger black holes could be formed - it just depends, how large primordial density fluctuations you'll put into it.

All of it is indeed just an ad-hoced mess fitted to the actual observations, which cannot be falsified.
Shinichi D_
4 / 5 (4) Nov 11, 2012

there`s no proof for such BH it`s only theory. More - if density of early Universe was so extreme to create such BH why all Universe didn`t colapse into one BIG BH? Universe was homogenous at the begining.


The term primordial BH was originally used for quantum black holes. Made very popular by S. Hawking, as he suggested such small BH would present a chance to observe Hawking radiation - the 'evaporation' of BHs. Guantum BH supposed to originate from density fluctuations of the very early universe. No such BH, nor the Hawking radiation was directly observed yet.
Later observations suggest that supermassive BH evolved very early in the young universe. So early, we might as well call them primordial supermassive BH.
The universe is smooth and flat in the large scale, but from the very first moment it carries a pattern of ancient density fluctuations.


roldor
1 / 5 (1) Nov 11, 2012
The whole galaxy could have been created out of cold H.
The stars and the BH(les) at the same time. Then then
star-formation is slowed down by the radiation.?
But, on the other hand, there should be an equilibrium
between the ionization and the recombination of the gas.
jptizzy
1 / 5 (8) Nov 11, 2012
"Astronomers have been puzzled" - Astronomers always seem to be puzzled. That's what happens when you try to explain reality with a completely flawed cosmological theory. So I predict that astronomers will continue to be 'puzzled' until their field wakes up and joins the real world of physics. Oh, and gravity does not order the universe; electricity actually orders the universe.

jsdarkdestruction
4.5 / 5 (8) Nov 11, 2012
hannes/cantdrive, how many accounts are you planning on making on here? do you think we dont all realize its you and not some random new guy chirping in in support of your eu fantasy? at the same time, do you realize doing so doesnt help you in any way? just because 3 people said it doesnt make it anymore true than the first.
rubberman
1 / 5 (1) Nov 12, 2012
@ 100 % of the universe is ruled by gravity, and BHs are part of that. Plasma effects are observably secondary on general relativity cosmology. - Tor

This can only be true if dark matters existence is verified. Which will never happen if it's only verification is the observed effect that it is supposedly producing.

Just a thought guys, in galaxies that old, what if every Ion carried the same charge? No possibility of any of them ever coming together. Perhaps star formation was initiated after the first reaction between two of these galaxies composed of Ions of opposing charges. Which if any of you standard theorists care to noodle around for a minute, can also explain why some galaxies attract each other and some appear to repel each other. The temperature of the ions isn't uniform throughout these galaxies. The black hole in the center "heating" the ions beyond their ability to coalesce doesn't fly for the entire galaxy, otherwise, why only old galaxies?
Fleetfoot
5 / 5 (3) Nov 12, 2012
Just a thought guys, in galaxies that old, what if every Ion carried the same charge? No possibility of any of them ever coming together.


Wot - no electrons???
rubberman
1 / 5 (1) Nov 13, 2012
Just a thought guys, in galaxies that old, what if every Ion carried the same charge? No possibility of any of them ever coming together.


Wot - no electrons???

Not according to the article.

It's the UV radiation "agitating" the ions of the entire galaxy that gives me pause, they are talking about the radiation from the central BH being powerful enough to have this effect across tens of thousands of light years, therefore no thermal equilibrium can be reached that would promote star formation.

http://adsabs.har...38..197S

My guess is without charge differentiation, there is no way for the ions, even in the cooler regions of the hydrogen cloud to begin to coalesce. If gravity was the initial mechanism for stellar formation, there would be stars in this galaxy.
Fleetfoot
5 / 5 (1) Nov 13, 2012
Just a thought guys, in galaxies that old, what if every Ion carried the same charge? No possibility of any of them ever coming together.


Wot - no electrons???

Not according to the article.


The comment was tongue in cheek of course but, to avoid confusion, from the article:

".. np and ne are the proton and electron densities, respectively .."

"Since we are concerned with the ionisation of neutral gas and its subsequent recombination, n_p = n_e = n."

http://arxiv.org/abs/1204.2881

There is also a subsequent note on the SKA where they repeat:

"n_p = n_e = n = n_0.e^(−r/R)"

http://arxiv.org/abs/1209.5136

My guess is without charge differentiation, there is no way for the ions, even in the cooler regions of the hydrogen cloud to begin to coalesce.


Quite the opposite, the recombination rate is key to the calculations. If the radiation level falls, the protons and electrons will revert to neutral hydrogen which can then coalesce under gravity.
rubberman
3.7 / 5 (3) Nov 13, 2012
Thanks Fleet, sorry i missed the tongue and cheek. And also thanks for the links. I wish more posters would explain why theories aren't supported by factual observation the way you have just done. Sometimes I wear my naivity like a hot pink jumpsuit when it comes to this stuff, I was not aware the UV effect from a quasar was so far reaching.
Fleetfoot
5 / 5 (4) Nov 13, 2012
Thanks Fleet, sorry i missed the tongue and cheek. And also thanks for the links. I wish more posters would explain why theories aren't supported by factual observation the way you have just done. Sometimes I wear my naivity like a hot pink jumpsuit when it comes to this stuff, I was not aware the UV effect from a quasar was so far reaching.


I've found a more recent paper which may be the source, I wish these press reports would cite the original but most are just copied around.

http://arxiv.org/abs/1210.1886

One point to consider is that once an atom has been ionised, it will not absorb another photon until it recombines, and recombination can emit a photon, so the level needed to maintain ionisation is less than you might expect.

It's a pleasant change to find someone here more interested in the science than the usual flame wars.
rubberman
3.7 / 5 (3) Nov 13, 2012

It's a pleasant change to find someone here more interested in the science than the usual flame wars.


Thanks. It's equally pleasant when people who have done the work and know the physics post in a fashion meant to educate as opposed to belittle. (I always try to take this route first as well, some of the characters here make that very difficult). I started coming to this site to learn about sciences that I had not been exposed to, it's nice to have my motivation validated.
Widdekind
1 / 5 (2) Nov 27, 2012
Profs. Curran & Whiting analyzed radio-galaxies & Quasars at high redshift (z>3). Radio-galaxies and radio-loud Quasars are generally large Elliptical galaxies. And, large Elliptical galaxies were the first galaxy-scale structures to form (z>3), from mergers, of smaller systems. So, the analysis seems to focus on large Elliptical galaxies, at high redshift, in the wake a major merger, when their central SMBH is feasting on gas & stars tidally torqued into its massive maw. Large Elliptical galaxies are known to be "dry" (gas poor) at present epoch, generally residing in large Clusters, wherein gas has been heated to high temperatures (T>e8K), in an ICM. Inexpertly, the authors may be describing the emergence, of large Elliptical galaxies, at high redshift, from major mergers, which generate intense AGN activity.

http://arxiv.org/abs/1204.2881