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Fraser
2004-Dec-01, 06:39 PM
SUMMARY: The Hubble Space Telescope has helped astronomers discover the youngest known galaxy in the Universe. This baby galaxy, located 45 million light-years away seems to be only 500 million years old (our own Milky Way galaxy, like many galaxies in the Universe is 12 billion years old). Its interstellar gas is "nearly pristine", comprised mainly of hydrogen and helium, with only a sprinkling of the heavier elements associated with older galaxies. This discovery gives astronomers an opportunity to understand how galaxies first formed.

View full article (http://www.universetoday.com/am/publish/youngest_galaxy_found)

What do you think about this story? Post your comments below.

wstevenbrown
2004-Dec-01, 06:55 PM
Does anybody know anything about the horseshoe-shaped thingie in the upper right of the picture? It seems blue enough to be associated with the dwarf. S

John L
2004-Dec-01, 06:57 PM
What horshoe shaped thingy? Do you mean the clouds of gas on the edge of this new dwarf galaxy, or the cluster of stars?

At least this shows that the stars formed from a primordial gas cloud of hydrogen and helium that collapsed in under its own gravity. No nuetron star cores here...

Greg
2004-Dec-01, 07:00 PM
Sounds like they made a pretty good case here for this being a new galaxy. Alot will be learned about galaxy formation if this is true. I do not think it is fair to say that this little galaxy is necessarily representitive of how larger glaaxies like ours formed. It may be more fair to say that studying this galaxy will tell us much about how dwarf galaxies are formed. Unless the authors feel there is enough dust in this cloud to form a larger galaxy, which I doubt. The environment in the early universe was probably much different than today. Rather than isolated pockets of gas there was likely gas and dust everywhere and the earliest phases of evolution may have been quite different than this example. There were also likely more little dwarfs like this around that likely interacted with each other which may have affected the early evolution of larger galaxies.

Guest
2004-Dec-01, 07:49 PM
It looks according to the picture that the spiral arms and bars are already forming... :unsure:

om@umr.edu
2004-Dec-01, 08:33 PM
This is an interesting story, Fraser.

It raises many questions.

What special conditions made it possible that:

1. "The baby galaxy managed to remain in an embryonic state as a cold gas cloud of primeval hydrogen and helium for most of the duration of the universe's evolution" ?

2. "As innumerable galaxies blossomed all over space this late-bloomer did not begin active star formation until some 13 billion years after the Big Bang, and went through a sudden first starburst only some 500 million years ago" ?

With kind regards,

Oliver
http://www.umr.edu/~om

antoniseb
2004-Dec-01, 08:41 PM
Originally posted by om@umr.edu@Dec 1 2004, 08:33 PM
It raises many questions.

Yes it does, but they aren't the sort of question where no rational answer will do. For example, this may have been a primordial cloud that was simply not dense enough to collapse into a galaxy forming cloud until some event happened, such as impacting the hot plasma surrounding a nearby cluster, or a close fly-by of another large gravitational object. Perhaps it was two gas clouds that have just now collided, or perhaps it was a gas cloud that fell into a dark matter cloud.

One thing is certain, it wasn't a collection of ten billion naked tiny neutron stars just waiting to accrete new star material.

John L
2004-Dec-01, 09:40 PM
Originally posted by Greg@Dec 1 2004, 02:00 PM
I do not think it is fair to say that this little galaxy is necessarily representitive of how larger glaaxies like ours formed. It may be more fair to say that studying this galaxy will tell us much about how dwarf galaxies are formed.
One theory of galaxy formation is that lots of little dwarf galaxies like this came first, and these then combined together into the larger galaxies we are used to seeing. I do not agree totally with this theory - it doesn't explain SMBH's in the heart of most galaxies - but, like you, I think there's still a lot to learn from an object like this.

om@umr.edu
2004-Dec-02, 04:32 AM
Originally posted by antoniseb@Dec 1 2004, 08:41 PM
One thing is certain, it wasn't a collection of ten billion naked tiny neutron stars just waiting to accrete new star material.
The question remains, Anton.

How did "primordial" H in this galaxy avoid fusion reactions for 13 billion years?

Why did the H suddenly start forming stars after 13 billion years?

With kind regards,

Oliver
http://www.umr.edu/~om

antoniseb
2004-Dec-02, 05:02 AM
Originally posted by om@umr.edu@Dec 2 2004, 04:32 AM
How did "primordial" H in this galaxy avoid fusion reactions for 13 billion years?
Why did the H suddenly start forming stars after 13 billion years?

Right, and I gave some plausible answers within the realm of main-stream astronomy. It will take further work to see which one is right, but this is not a mystery that invokes the collapse of main-stream astronomy.

Greg
2004-Dec-02, 05:43 AM
I was wondering when the "Steady state" enthusiasts would jump in and begin claiming that this finding helps them to debunk the big bang theory altogether. I would think that would make for some interesting discussion. I do not want to speak for Oliver, but I think that the inescapable conclusion about these findings is that all the stars are very young. Whether or not burned out neutron stars can form the nuclei of a second generation of main sequence stars after this early phase of a galaxy's evolution can be debated (and has been ad nauseum before.) Information about this blue dwarf will likely help clear up that question for anyone still not satisfied with the results of past discussions on this topic.

guest_star
2004-Dec-02, 08:58 AM
Another question is : How did this interstellar mateial avoid dispersion by forces of Dark Energy, which is prevailing in the space between galaxies/clusters.
Is it part of some known galaxy cluster?
I would like to know the position of the gas/dust cloud (no plasma here ?!) a few billions years ago.
What is the shape of this baby?

om@umr.edu
2004-Dec-03, 04:15 PM
Originally posted by Greg@Dec 2 2004, 05:43 AM
I do not want to speak for Oliver, but I think that the inescapable conclusion about these findings is that all the stars are very young. Whether or not burned out neutron stars can form the nuclei of a second generation of main sequence stars after this early phase of a galaxy's evolution can be debated (and has been ad nauseum before.)
Hi, Greg.

The question is whether H itself existed for 13 billion years ?

A free neutron decays to H with a half-life of about 11 minutes.

Thus, the H we observe today could have been "stored" as neutrons, if neutrons are "stored" in neutron stars at +10-22 MeV more energy than a free neutron.

See: ""Neutron repulsion confirmed as energy source", Journal of Fusion Energy vol. 20 (2003) pages 197-201.

http://web.umr.edu/~om/abstracts2003/jfe-n...-neutronrep.pdf (http://web.umr.edu/~om/abstracts2003/jfe-neutronrep.pdf) ***

With kind regards,

Oliver
http://www.umr.edu/~om

antoniseb
2004-Dec-03, 05:42 PM
Originally posted by om@umr.edu@Dec 3 2004, 04:15 PM
Thus, the H we observe today could have been "stored" as neutrons, if neutrons are "stored" in neutron stars at +10-22 MeV more energy than a free neutron.
One of the many problems with this model is that even if the early universe were populated with neutron stars, the neutrons could not escape from the neutron star's gravity well to decay and populate the interstellar medium with Hydrogen, and to create pristene clouds of Hydrogen and Helium which might later form galaxies.

Greg
2004-Dec-03, 10:59 PM
Hi, Oliver.
You do raise some interesting questions regarding how this hydrogen could have remained intact for 13 billion years. To answer this I would need to look up the decay products of hydrogen and its half-life, both of which I currently do not have handy. It could be that the answer to how this dwarf formed is not as simple as it appears at first. However since I believe that you cannot even get neutron stars without first going through a generation of H+/He stars, I do not see how a large cluster of neutron stars could get so far away from the nearest galaxy in order to decay into this blue dwarf. If you mean to imply that neutron stars formed from the big bang then their fast decay rate into hydrogen should mean that this galaxy should have formed long before now with all of the other ones. So I am not sure how finding this late blooming galaxy would help you.

John L
2004-Dec-03, 11:33 PM
Originally posted by Greg@Dec 3 2004, 05:59 PM
To answer this I would need to look up the decay products of hydrogen and its half-life, both of which I currently do not have handy.
Hydrogen is a single proton. Although there are estimates for the half-life of a proton, none have ever been observed to decay naturally. We smash them all the time in accelerators, but according to Wikipedia (http://en.wikipedia.org/wiki/Proton_decay) an estimated half-life for a Proton 10^36 years. Longer than the life of the universe so far.

om@umr.edu
2004-Dec-04, 06:28 AM
Originally posted by Greg@Dec 3 2004, 10:59 PM
You do raise some interesting questions regarding how this hydrogen could have remained intact for 13 billion years.

If you mean to imply that neutron stars formed from the big bang then their fast decay rate into hydrogen should mean that this galaxy should have formed long before now with all of the other ones.

So I am not sure how finding this late blooming galaxy would help you.
Hi, Greg

We have reason* to believe that neutrons in a neutron star are in an "excited state" of +10-22 MeV relative to free neutrons, but they do not decay into H unless emitted as free neutrons.

http://web.umr.edu/~om/abstracts2003/jfe-n...-neutronrep.pdf (http://web.umr.edu/~om/abstracts2003/jfe-neutronrep.pdf) *

If the Big Bang thus compressed nuclear matter into neutron stars instead of forming dispersed nuclear matter in the form of H atoms, then this might provide a mechanism to "store" H or its neutron parent for billions of years.

*Our conclusion is based on systematic properties of all 2,850 known assemblages of neutrons and protons. On the other hand, Duane pointed out a theoretical model of neutron stars which predicts that neutrons in a neutron star are "tightly bound state" at -93 MeV relative to free neutrons.

The question is whether neutron stars are great sources of energy or more dead than Fe-56, the most tightly bound of the 2,850 known nuclides.

With kind regards,

Oliver
http://www.umr.edu/~om

(Q)
2004-Dec-04, 06:09 PM
We have reason* to believe that neutrons in a neutron star are in an "excited state"

Uh, considering that fission no longer occurs in a neutron star, where is the energy source that "excites" the neutrons?

om@umr.edu
2004-Dec-04, 07:17 PM
Hi, (Q).

The energy source is repulsive interactions between neutrons.

See: "Neutron Repulsion Confirmed As Energy Source", Journal of Fusion Energy, volume 20 (2003) pages 197-201.

http://web.umr.edu/~om/abstracts2003/jfe-n...-neutronrep.pdf (http://web.umr.edu/~om/abstracts2003/jfe-neutronrep.pdf)

With kind regards,

Oliver
http://www.umr.edu/~om

(Q)
2004-Dec-04, 07:40 PM
The energy source is repulsive interactions between neutrons.

What repulsive interactions?

Neutrons are electrically neutral, that's why they are called neutrons.

If gravity can turn protons and electrons into neutrons, how is it possible the so-called 'repulsive interactions' can overcome gravity?

Greg
2004-Dec-04, 07:54 PM
THe notion that neutron "stars" (agglomerations) formed from the big is certainly interesting, but I would think you may have a hard time proving that one, Oliver. If this were true I would think we would still be able to see clouds of neutrons out there somewhere, some of which are forming neutron stars. At this point I do not see anything significant or pervasive enough to contradict the prevailing theory of Hydrogen/Helium progenitor stars originating from the big bang.

om@umr.edu
2004-Dec-04, 09:46 PM
Originally posted by Greg@Dec 4 2004, 07:54 PM
1. The notion that neutron "stars" (agglomerations) formed from the Big Bang is certainly interesting, but I would think you may have a hard time proving that one, Oliver.

2. If this were true I would think we would still be able to see clouds of neutrons out there somewhere, some of which are forming neutron stars.
Hi, Greg.

1. I agree it will be difficult to prove that many billion years ago "neutron stars (agglomerations) formed from the Big Bang."

2. If this were true, we would now see clouds of Hydrogen out there surrounding neutron stars.

With kind regards,

Oliver
http://www.umr.edu/~om

PS - (Q) please read:
1. "Neutron Repulsion Confirmed As Energy Source", Journal of Fusion Energy, volume 20 (2003) pages 197-201.
http://web.umr.edu/~om/abstracts2003/jfe-n...-neutronrep.pdf (http://web.umr.edu/~om/abstracts2003/jfe-neutronrep.pdf)
2. "Nuclear systematics: III. The source of solar luminosity", Journal of Radioanalytical and Nuclear Chemistry volume 252 (2002) pages 3-7.
http://web.umr.edu/~om/abstracts2001/nuc_sym3.pdf

antoniseb
2004-Dec-05, 04:10 PM
Originally posted by om@umr.edu@Dec 4 2004, 09:46 PM
2. If this were true, we would now see clouds of Hydrogen out there surrounding neutron stars.
How are you suggesting, that "if this were true", that the neutron->Hydrogen would escape from the neutron stars? Would it make it all the way to interstellar space? or would it go into a low orbit around the neutron star somehow?

10 to 22 MeV is not actually enough energy for a neutron to escape from a neutron star's surface long enough to be likely to decay into Hydrogen, and even if it does decay, the proton will be falling back to the neutron star's surface VERY soon.

Greg
2004-Dec-06, 06:43 PM
Well, I'll try to describe better my point about clouds of neutrons forming neutron stars. If you assume that neutron agglmerations formed after the big bang, you have to describe where they came from. Besides the process which we now know that generates them, which is the collapse of a hydrogen/helium star of around 3-10 solar masses in size. For a neutron star to form immediately after the big bang, one must assume that neutron precipitated from the original hot primordial soup as it cooled. They would not have formed in clumps but rather scattered and individually as we think hydrogen and helium did. Pertubations from inflation would have allowed some to form into clumps and knots and from the first neutron stars. So before there was a neutron star as your thinking goes, there should have been clouds of neutrons in my opinion. Such clouds should still exist today in a primordial and unclumped state for us to see. Yet the only such pristine clouds we do see are made of hydrogen, remarkably similar to the on in this article. This is why I fail to see how this article advances the early neutron star formation theory. Finding a large cloud of neutrons forming neutron stars would be good for this theory, however.

Greg
2004-Dec-06, 06:50 PM
You may have better luck trying to associate another form of dark matter such as neutrinos as to why this galaxy is forming so late. There have been reported agglomerations of dark matter in otherwise empty space not associated with regular matter. Perhaps one of these is partly responsible for late-forming collections of dust.

antoniseb
2004-Dec-06, 07:06 PM
Originally posted by Greg@Dec 6 2004, 06:43 PM
This is why I fail to see how this article advances the early neutron star formation theory. Finding a large cloud of neutrons forming neutron stars would be good for this theory, however.
If neutron stars were formed in the early universe from simple gravitational collection of neutrons, it would have to have been in the first hour or so, much after that and there wouldn't be many free neutrons to collect, as they decay to protons et. al. with a twelve minute half-life. On the other hand, if we take Dr. Manuel's theory completely, the neutrons couldn't easily collapse to this form, because they naturally repel each other, which kind of keeps them operating in a perfect gas.

In any case these conditions are ones that we will never observe locally.

John L
2004-Dec-06, 08:12 PM
I have a simple question I've never thought of asking: Where did all of the neutrons in the universe come from if their half-life is measured in minutes? My educated guess is they were created during the hydrogen (and higher) fusion process in the cores of stars. Is this correct?

I understand that the neutrons in a neutron star are created when the gravity of the core exceeds the degeneracy pressure, but is lower than what is needed to create a black hole, and causes the protons, electrons, and neutrinos to combine into a gravitationally bound structure made almost entirely of neutrons.

Greg
2004-Dec-06, 09:49 PM
Good to know. A little review of nuclear chemistry goes a long way in this instance. It would seem to me that it should be relatively easy to spot such neutron stars in the universe, considering we assume for a second that they could have been created. Most likely some or all of them would be set spinning by the process of their creation or events thereafter. We all know what happens to infalling matter around spinning neutron stars, most of it gets expelled violently along its polar axis and we call the object a pulsar. If a whole slew of pulsars (some I imagine of enormous size) were present shortly after the big bang, their signature emissions should turn up in observations going back to whatever time is within their life expectancy. Unless one wishes to consider quasars or GRBs as potential candidates for this evidence, I think that we can already say that this did not happen. The reason being that the early universe should be populated with an enormous number of these objects and we in fact see very few of them.

John L
2004-Dec-06, 10:01 PM
Greg,

There is a smallest and largest size to a neutron star, and that is between about 1 and 3 (editted from 4 to 3 after antoniseb's post below) solar masses. Below one solar mass, the gravitational force is not sufficient to overcome the degeneracy pressure and force protons and electrons together, resulting in a white dwarf instead. Of course, that is if the neutron star were born in the death of a star. The maximum size (I don't know the exact mass) is where the gravitational force is great enough that it forms a black hole (although some speculate that between the neutron star and the black hole is a quark star made entirely of free quarks). The overall range between the two extremes (white dwarf to black hole) isn't very large...

And would a neutron star formed 13 billion years ago still be spinning? I know they can have fast spin rates at birth (conservation of angular momentum with a radical decrease in radius), but would that last all the billions of years since the big bang? Maybe the distant bursts we see are them, but none near by should still be spinning unless acted on by an outside force...

antoniseb
2004-Dec-06, 10:22 PM
Originally posted by John L@Dec 6 2004, 10:01 PM
There is a smallest and largest size to a neutron star, and that is between about 1 and 4 solar masses.
Hi John L. We've covered this in the Iron Sun thread a few times. The heaviest mass for a neutron star is thought to be about 3 solar masses, you are right that above this it crushes to become a black hole, or something like a black hole. It may be that neutron stars near that limit have degenerate quark matter in their cores, but we usually still call them neutron stars.

As to the low end, we believe that a new netron star cannot be created in a supernova with a mass less than about one solar mass. There's pretty good work, and observations showing this to be the case, however, there is theoretical work saying that you could possibly maintain a neutron star-like object with as little as 0.3 solar masses, or maybe as little as 0.1 solar masses. There is no known way that these object could be created.

While he hasn't explicitly come out and said so, I imagine that Dr. Manuel is bringing up this idea of primordial neutron stars, created as a side effect of the big bang as a possible way that the sun might have a neutron star much less than a solar mass inside it.

This mechanism would not be able to explain the Red Dwarfs we see with less than 0.1 solar masses, and the small neutron star business is a little odd since the tiny ones would be giving off more of the sort of radiation than the big ones do. This means that red dwarfs should be much brighter than the sun, if his models were taken seriously... Similarly, these minimum mass neutron stars, if they are emitting neutrons as he says, will eventually get below the minimum mass, in which case they will explode with a supernova like blast [something that has never been observed from a red dwarf], but these are side issues, which we can take up in the Iron Sun thread if Dr. Manuel decides that he wants to attach this idea to his model. I suspect he won't.

John L
2004-Dec-06, 10:39 PM
I have a question that might bring the neutron star issue back on topic. Doc O has suggested that this very young galaxy is made up of neutron stars that have only recently lit up; I assume after having accreted matter, perhaps from a swarm of them finally intersecting clouds of hydrogen, or perhaps from the neutron stars emitting protons (Doc O's idea), and then reacreting them to form the new stars.

What makes a neutron star visible to us when it is a naked neutron star? Is it only when it is a pulsar? Does it have to be acreting matter? Could we see them out to any substantial distance and find small populations of naked (primordial) neutron stars roaming the intergalactic medium waiting to encounter their own clouds of gas and dust (or produce them) to form a new dwarf galaxy of stars?

Doc O, if you read this, please let me know what you think the process is in a little more detail than some of your previous posts. Specifically, what do you think the answers to my questions above are (which is a correct model to you?).

Of course, Doc O, you know from our previous discussions on the Iron Sun thread that I don't agree with your ideas, but I'm willing to play devil's advocate and try to see things from your side of the fence...


Thank you :D

antoniseb
2004-Dec-06, 10:54 PM
Originally posted by John L@Dec 6 2004, 10:39 PM
What makes a neutron star visible to us when it is a naked neutron star? Is it only when it is a pulsar? Does it have to be acreting matter?
By the usual theories, neutron stars that aren't accreting give off xrays as they cool. Before they are a few milllion years old, they are too dim to be detected even from only a few light years away, except as gravitational lenses in the lucky chance of an observed occultation.

According to Dr. Manuel's model, they should be blasting out about two thirds of the solar luminosity until they shrink to the minimum size [when they explode]. Except in the earliest stages, when the neutron star is naked, this luminosity should be seen as stellar-like emissions from the surface Hydrogen and other atoms.

Please, Dr. Manuel, if this is not a good description of your model, correct me.

Duane
2004-Dec-07, 01:25 AM
Just to add a couple of quick points. A neutron star (NS) does not form until a mass has accreted 1.4 Solar masses (Sm) of material. That is the Chandrakasar Limit, and as antoniseb says, there is lots of discussion about that in the IS thread.

At somewhere about 5 Sm the Oppenhiemer-Volkoff Limit is reached and the object collapses into a black hole. (The upper end is not well known, is depends on equations of state that are WAY beyond me!)

The smallest known NS is 0.96Sm +/- .19Sm. Several (actually most) cluster at about 1.35Sm +/- 0.04Sm. In all cases, the derived mass of the NS is based on it's effect on a companion star.

In a Type II SN, the core reaches 1.4 Sm of iron, triggering the collapse. There is no known way for such an object to lose that mass except in the most extreme enviroments--merging with a black hole, etc.

The NS we see orbiting companion might have arisen in a Type I SN, where the white dwarf (WD) accreted enough material to exceed the Chandra Limit and collapse into a NS. The resulting explosion might release enough energy to blow off part of the neutron shell, thus allowing the smaller mass. This is very very speculative stuff. Most white dwarfs that accrete that much material blow themselves to bits.


A old neutron star would be essentially invisible until it was very close. That is because the object cools with time, and this cooling is speedier than a white dwarf because of (damn antoniseb, what is that called?) It will shine with heat energy for maybe a few hundred thousand years then be gone.

One NS was recently seen where it had accretted material from a cloud of ISM it was passing through. The accretion caused it to light up again for a little while, but it too will lose that new heat and become invisible again.

antoniseb
2004-Dec-07, 01:52 AM
Originally posted by Duane@Dec 7 2004, 01:25 AM
antoniseb, what is that called?
I'm having the same block you are, sorry.

Greg
2004-Dec-07, 04:28 AM
John L,
Thanks for the reminder on the limits of neutron star size. I was speculating that if Doc O's neutron stars existed in the early universe then we should be able to see evidence of them in the early universe, not necessarily now. If you believe in the decay rate that Doc O refers to then these early neutron stars would have degraded into hydrogen by now. I would think that there would be ample opportunities for these stars to interact with other stars and hydrogen they are releasing (hypothetically speaking) to get them to spin. There should be enough hydrogen around for them to act like pulsars. I kind of threw this fanciful speculation in as a segway to mention a recent article I read about the discovery of the largest GRB ever found originating from a well known pulsar in our own galaxy. I was hoping it would get covered by Fraser, but couldn't resist mentioning it now. I will include a reference to the site where I found it if anyone is interested and hasn't read about it (http://www.newscientist.com/news/news.jsp?id=ns99996736)

antoniseb
2004-Dec-07, 04:35 AM
Originally posted by Greg@Dec 7 2004, 04:28 AM
a recent article I read about the discovery of the largest GRB ever found originating from a well known pulsar in our own galaxy.
I pointed this out in a thread in the Other Stories section. This was not a GRB in the usual sense. This was one bright quick flash of xrays. It lasted about a billionth the duration of a normal short GRB.

Greg
2004-Dec-07, 10:08 PM
ok, thanks. I'll check out the thread.

Duane
2004-Dec-08, 03:18 PM
I have deleted Dr Manuels last post because he did not answer antoniseb's question and this thread is about the possible causes of this late blooming galaxy and not about the steps that should be taken to confirm the sun shines because of n-n repulsion.

Please Dr Manuel, feel free to anwer antoniseb, but please also refrain from posting a long dissertation on the possibility the sun has an iron core. I recognize there may be some overlap, but your last went over the line.

om@umr.edu
2004-Dec-08, 05:38 PM
Originally posted by antoniseb@Dec 6 2004, 10:54 PM
Please, Dr. Manuel, if this is not a good description of your model, correct me.
Hi, Anton.

This question does not lend itself to a simple "Yes" or "No" answer.

I tried to explain the immature state of our understanding of neutron stars, but Duane decided to delete that.

Sorry,

Oliver
http://www.umr.edu/~om

antoniseb
2004-Dec-08, 06:20 PM
Originally posted by om@umr.edu@Dec 8 2004, 05:38 PM
I tried to explain the immature state of our understanding of neutron stars, but Duane decided to delete that.
I didn't read the posting. I think I can move the question to the IS thread. I'd be looking for an answer that specifically points to where my assesment of your model disagrees with your actual understanding. I wasn't looking for a broad, 'nobody knows' kind of answer. Look for the copy of the question in the IS thread.

This topic has drifted away from the initial subject. I think Duane is right to move us along. Sorry Duane, I should have taken it there myself several posts ago.

Duane
2004-Dec-08, 09:37 PM
Originally posted by om@umr.edu@Dec 8 2004, 05:38 PM
I tried to explain the immature state of our understanding of neutron stars, but Duane decided to delete that.


I'm sorry, but I did not get that from the material you posted. Rather, you talked exclusively about how a neutron star in our sun might be detected. You said nothing about our understanding of neutron stars.

As for neutron stars, as my post above attests, we actually do have a pretty good understanding about them in general. It is the details of the very core of the neutron star that we have little knowledge about, although Equations of State and theories of a Bose-Einstein condesate seems to be unravelling some of the mysteries.

Dr Manuel's suggestion of a host of neutron stars forming with the big bang seems pretty remote to me. Frankly, where is the material needed to form such objects? A free neutron will decay with an 11 minute half-life, so it can't be clouds of neutrons. As there is such a small window between forming a neutron star and forming a black hole (figure a lower limit of 1.4 Sm for forming a neutron star and a lower limit of about 5 or 6 Sm for forming a black hole, and you are talking only a small 3.5 Sm difference), as I said before, you would expect that if anything, lots of black holes formed. Maybe even supermassive black holes!

Maybe that helps to explain why this young galaxy suddenly turned on. Maybe the SMBH at it's centre had not accretted enough material to set into motion the ripples needed in the cloud to initiate star formation. Or maybe the SMBH wasn't even there until just recently--perhaps its formation supplied the impetous for the cloud to begin forming stars.

om@umr.edu
2004-Dec-09, 04:13 AM
Originally posted by Duane+Dec 8 2004, 09:37 PM--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (Duane @ Dec 8 2004, 09:37 PM)</td></tr><tr><td id='QUOTE'> <!--QuoteBegin-om@umr.edu@Dec 8 2004, 05:38 PM
I tried to explain the immature state of our understanding of neutron stars, but Duane decided to delete that.


You said nothing about our understanding of neutron stars.

a. Dr. Manuel&#39;s suggestion of a host of neutron stars forming with the big bang seems pretty remote to me.

b. Frankly, where is the material needed to form such objects?

etc.

[/b][/quote]
Hi, Duane.

You act unilaterally as moderator; then as advocator of a particular point of view ?

Good luck&#33;

Oliver
http://www.umr.edu/~om

antoniseb
2004-Dec-09, 02:25 PM
Originally posted by om@umr.edu@Dec 9 2004, 04:13 AM
You act unilaterally as moderator; then as advocator of a particular point of view ?
Duane is a moderator for this entire forum, and a very good one. He must be allowed to take actions to keep the forum so that it follows the rules we have set for it. In this case, staying on-topic, and not advertising. In these matters, we all use our judgement, and I believe that this was a difficult case, but he used good judgement. You don&#39;t like it because he disposed of your posting.

If you are hoping to get as moderator who agrees with your view in the Iron Sun debate to moderate, we might as well shut down the topic and kick you of the forum. That is very unlikely to happen. Please stop complaining about the choices of the moderators, and enjoy what you do like about the UT forum.

VanderL
2004-Dec-09, 03:41 PM
If you are hoping to get as moderator who agrees with your view in the Iron Sun debate to moderate, we might as well shut down the topic and kick you of the forum.

:huh:

I agree when moderators try to keep discussions to follow the rules and keep the postings on topic, but I can also understand Oliver&#39;s point of view. Here&#39;s just a thought: maybe it is possible for moderators to "moderate" in topics where they don&#39;t also contribute strongly in the discussion?

Cheers.

antoniseb
2004-Dec-09, 03:53 PM
Originally posted by VanderL@Dec 9 2004, 03:41 PM
maybe it is possible for moderators to "moderate" in topics where they don&#39;t also contribute strongly in the discussion?
For my part, I cannot think about the topic without caring enough to contribute. I could not moderate any thread by that rule. I also don&#39;t want the task of reading threads I don&#39;t care about.

Duane
2004-Dec-09, 04:50 PM
You act unilaterally as moderator; then as advocator of a particular point of view ?


What I can&#39;t have an opinion? If everyone sticks to the topic, no "actions" need to be taken.


maybe it is possible for moderators to "moderate" in topics where they don&#39;t also contribute strongly in the discussion?


I agree with antoniseb on this one. It is especially true when the topic is technical and requires the moderator have some knowledge of the subject.

Speaking of getting off topic, I believe we were discussing how this young galaxy might have formed so late in the evolution of the universe?

antoniseb
2004-Dec-10, 02:46 PM
I have answered this in the Iron Sun thread in the Alternative Theories section.

Duane
2004-Dec-10, 04:14 PM
Please stay on topic.

Sher1109
2005-Mar-09, 02:59 PM
Hello,

I am doing some research on this topic, the youngest galaxy I Zewicky 18, and I was wondering if anyone could direct me as to where to get more information on this subject. I want to find out things like, the hypothesis being examined, where this discovery is going in terms of finding out new information, what does this mean for us on Earth, will the things we learn from it help us in anyway? I need answers to all these questions so any help would be greatly appreciated.

I have to have my paper done in 2 weeks and I dont like to leave things to the last min. but I have I have been trying to pick a topic to write about. The topic has to be something that has been discovered in the last 3 years so I wanted to do research on something interesting.

Thank you tto anyone who can help me&#33;&#33;&#33;&#33;&#33; :)