Globular clusters

BMAONE23 · Post by **BMAONE23** » Tue Mar 20, 2007 4:50 pm

I was looking around last night (though I cannot locate the article now) and found an article about newly found star clusters in the galactic plane. These were previously thought to be nebulae but were recently discovered to be globular clusters of "Old Stars". containing as many as 100,000 stars with 65,000 solar masses. This made me think about globular clusters. They are often refered to as being ancient star clusters that inhabit the Halo around the galactic center and seem to be older than most other things in the galaxy. I was thinking that these star clusters might in fact be the remnants of ancient primordial galaxies that congealed into forming the regular galaxies we see today.

Well, I found the article on Space.com

http://www.space.com/scienceastronomy/0 ... uster.html

This was the actual article

http://www.msnbc.msn.com/id/17688386/

but they are very similar in wording

astro_uk · Post by **astro_uk** » Wed Mar 21, 2007 2:20 pm

HI BMAONE23

GCs aren't thought to be "congealed" collections of stars. They are a collection of stars that formed from the same star forming region. All stars form in stellar nurseries, most slowly drift out of the star forming region over time, when GCs form there are so many stars formed so quickly that the stars remain gravitationally bound even after most of the mass of the cloud is dissapated by supernovae of the larger stars. GCs are very useful because the stars in them all formed from the same gas cloud at the same time, hence they all have essentially the same age and same initial abundance of heavy elements. They can therefore be used to work out the conditions in the galaxy when they were formed/

Most GCs did seem to form very early in the Universe though, quite possibly in the small protogalaxies that merge to form larger galaxies.

BMAONE23 · Post by **BMAONE23** » Wed Mar 21, 2007 2:55 pm

Astro,
Perhaps "congealed" is the wrong word in this case but the thought track is:
As the early universe cools, protons, neutrons, and electrons can combine to form atoms. Further cooling allows for densities of these atoms to form allowing for the development of short lived, megastars. These act to draw in even more primordial gas, further cooling the surrounding space and allowing for slightly smaller stars to form. The megastars hypernova after a few million years exciting the surrounding gases and spawning the development of a new type of star cluster, what we call globular clusters.

These new star clusters affect gravity differently in that their effect is spread out over a larger area. As more clusters form, they begin to feel a garvitational attraction and, over hundreds of millions of years, pull groups of clusters together forming rudamentary protogalaxies. They act to compress the trapped gases that lie between them further exciting this gas and causing a new burst of star formation.

This compresson also causes those clusters in the center to be further compressed creating a situation where stars collide and merge but instead of forming a new megastar (it is now too cool for them to exist), this merger forms a black hole which rotates pulling in any nearby matter and creating gravitational pull on the remaining stars in a circular motion creating the spiral form. The rotation causes new star formation in the remaining gasses. Those Globular Clusters that reside around the galaxy, in the Halo, are unaffected and remain relatively unchanged for billions of years while the rest of the galaxy revolves and evolves over time.

Just a theory though

harry · Post by **harry** » Thu Mar 22, 2007 5:02 am

Hello All

BMAONE23 said

This compresson also causes those clusters in the center to be further compressed creating a situation where stars collide and merge but instead of forming a new megastar (it is now too cool for them to exist), this merger forms a black hole which rotates pulling in any nearby matter and creating gravitational pull on the remaining stars in a circular motion creating the spiral form. The rotation causes new star formation in the remaining gasses. Those Globular Clusters that reside around the galaxy, in the Halo, are unaffected and remain relatively unchanged for billions of years while the rest of the galaxy revolves and evolves over time.

Basically I agree with what you say.

Halo stars are stars that have been pushed or ejected from the centre either by a black hole or by sling shot effect.

Star formation requires a gravity sink, just dust a gas cannot create stars.

What do you mean by primodial gas?

BMAONE23 · Post by **BMAONE23** » Thu Mar 22, 2007 4:38 pm

According to BB theory, no atoms existed until the universe had time enough to cool sufficiently to allow for their formation then the first to form was hydrogen. It is this free hydrogen that has not been absorbed into the creation of new stars that I am refering to as Primordial Gas.

harry · Post by **harry** » Fri Mar 23, 2007 10:30 pm

Nereid · Post by **Nereid** » Sat Mar 24, 2007 2:48 am

harry wrote:Hello BMAONE23

The BBT is only a theory.

We need to see other options.

Interesting reading.

http://thunderbolts.info/tpod/2004/a...on-bigbang.htm
http://thunderbolts.info/tpod/2005/a...214bigbang.htm
http://thunderbolts.info/tpod/2006/a...letcluster.htm
http://thunderbolts.info/tpod/2004/arch/040914star.htm
http://thunderbolts.info/tpod/2005/a...50401sofar.htm
http://thunderbolts.info/tpod/2005/a...tempsspace.htm
http://thunderbolts.info/tpod/2005/a...5spacetemp.htm
http://thunderbolts.info/tpod/2006/a...angscience.htm

The Big Bang theory has done enough damage by leading people on the wrong path.

To repeat what I said on another thread here in the Asterisk Cafe:

harry, if you wish to keep presenting this kind of material, I will ask you to be prepared to defend it.

In particular, I will ask you to be prepared to answer questions, and challenges, to it, in terms of:

a) its internal consistency

b) its consistency with well-established theories with domains of applicability that overlap

c) (above all) consistency with relevant, good observational and experimental results.

Specifically, I ask you to choose one of the claims in any of these threads, state it (in quantitative form) and declare your preparedness to defend it.

If you are prepared to do this, please do not post such material in this forum.

BMAONE23 · Post by **BMAONE23** » Sat Mar 24, 2007 4:29 am

harry wrote:Hello BMAONE23

The BBT is only a theory.

We need to see other options.

..................

The Big Bang theory has done enough damage by leading people on the wrong path.

Harry,
All theories are just that, Theories. None have absolute proofs. Even "Steady State Theory" is just a theory and has no indesputable proofs. All proposed proofs are from data that is open to interpretation and can be interpreted differently depending on which "Theory" you hold to.

harry · Post by **harry** » Sat Mar 24, 2007 4:37 am

Hello BMAONE23

I cannot argue with that,,,,,,,,,,,,,,I agree

astro_uk · Post by **astro_uk** » Sat Mar 24, 2007 7:55 pm

Hi BMAONE23

Much of what you say is probably true, we know GCs could potentially be very important in the early stages of star formation. From the heavy elements that these objects have, we know that they formed as probably only the 2nd or 3rd generation of stars, and that possibly the generations of stars before them were very massive stars, unlike anything seen in the Universe today. This paper deals with these topics:

http://arxiv.org/pdf/astro-ph/0605210

The other thing is that the earliest stars formed at a time when the Universe was made up of mostly atomic hydrogen. It was the first few generations of stars that produced enough high energy photons to ionise hydrogen into a proton and electron as we generally see now.

One thing I would say though, is that the first stars probably did not attract any matter, the amount of radiation pressure from them would be so massive that it would tend to keep the regions around them swept clean. This radiation pressure could however trigger starformation in nearby clumps of gas.

harry · Post by **harry** » Sun Mar 25, 2007 12:07 am

Hello Astro

You said

Much of what you say is probably true, we know GCs could potentially be very important in the early stages of star formation. From the heavy elements that these objects have, we know that they formed as probably only the 2nd or 3rd generation of stars, and that possibly the generations of stars before them were very massive stars, unlike anything seen in the Universe today. This paper deals with these topics:

How can you say that the generation before were very massive and unlike anything seen today?

The processes within the universe repeat themselves.

I have read
http://arxiv.org/PS_cache/astro-ph/pdf/0605/0605210.pdf

5. SUMMARY
We present [/Fe], metallicity, and age distributions of
globular clusters in elliptical, lenticular, and spiral galax-
ies, that were derived from Lick line index measurement
and identify a population of globular clusters with ex-
treme [/Fe] ratios. The main results of our study of
extremely -enriched globular clusters are: i) they are
predominantly found in early-type galaxies, ii) most of
these highly -enriched globular clusters are old (t > 8
Gyr) and cover the metallicity range −1. [Z/H] .0, iii)
a comparison with supernova yield models suggests that
the progenitor gas clouds of these globular clusters were
predominantly enriched by massive stars (&20M⊙), iv)
given the lower average [/Fe] ratios of the diffuse stellar
population in early-type galaxies, our results suggest that
the extremely -enhanced globular clusters are members
of the very first generation of star clusters formed, and
that their formation epochs likely predate the formation
of the majority of field stars in giant early-type galaxies.

The above results could be explained not by assuming that the Big Bang theory is correct and than proceeding to back up the BBT, but!!!! by a recycling process.

Astro said

The other thing is that the earliest stars formed at a time when the Universe was made up of mostly atomic hydrogen. It was the first few generations of stars that produced enough high energy photons to ionise hydrogen into a proton and electron as we generally see now.

How can you say that?

You say that as if it was fact.

If the universe was made up of H: For how long was it like that?. What was before? Why wasn't something going on? Was it waiting for the Big Bang?

One thing I would say though, is that the first stars probably did not attract any matter, the amount of radiation pressure from them would be so massive that it would tend to keep the regions around them swept clean. This radiation pressure could however trigger starformation in nearby clumps of gas.

Astro do you know the phases of matter?
The above statement in my opinion is not logical.

On one hand you speak as though you know the process of star formation and on the other hand you do not follow through with that logic.

astro_uk · Post by **astro_uk** » Tue Mar 27, 2007 11:40 am

I'm sorry Harry but you are wrong, essentially everything in your last post is mistaken. But thanks for playing.

How can you say that the generation before were very massive and unlike anything seen today?

Simple from dozens of lines of evidence we know tha the material produced in the BB was mostly hydrogen (about 75%), helium (about 24%) and trace amounts of lithium etc. Stars that form today are made up of larger fractions of elements heavier than Hydrogen, these other elements allow radiation to be emitted from the gas which form stars much more efficiently than a mix of only H and He. This means large gas clouds tend to break up into many smaller stars. In the early U, when there was only H and He, the gas cloud could continue to collapse without breaking up as much, creating stars of mass > 100Msun. Stars larger than a few tens of Msun are very rare today, but probably common in the early days of the Universe.

The processes within the universe repeat themselves.

You often state words to this effect but it is nothing more that a quasi-religious belief on your part unsupported by the facts.

The above results could be explained not by assuming that the Big Bang theory is correct and than proceeding to back up the BBT, but!!!! by a recycling process.

Feel free to get back to me when you have written the paper that demonstrates this, I could well end up being the referee on it anyway.

How can you say that?

You say that as if it was fact.

If the universe was made up of H: For how long was it like that?. What was before? Why wasn't something going on? Was it waiting for the Big Bang?

The H was formed in the BB Harry, even you must understand that. It is fact, its been measured through things like quasar sight lines. When the H was first formed it was ionised, simply a plasma of protons and electrons, as the Universe cooled the protons and electrons recombined. This happened when the CMB was created. Viola, Hydrogen, which can later be reionised by the UV light from stars, exactly like we see today.

Astro do you know the phases of matter?
The above statement in my opinion is not logical.

On one hand you speak as though you know the process of star formation and on the other hand you do not follow through with that logic.

Your opinion is irrelevant you don't know what your talking about. I have the benefit of facts on my side. Time for some remedial first school physics. Light exerts a pressure as light carries momentum, a very massive star gives off a lot of light, this light pushes any gas and dust away. Simple. How do you think the very pretty things like the pillars of creation get formed? Light from massive stars sweeping the region around them clear, thats how.