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Swift
2011-Jun-15, 10:08 PM
From PR Newswire (http://www.prnewswire.com/news-releases/nasas-chandra-finds-massive-black-holes-common-in-early-universe-123925219.html) (similar stories on CNN and elsewhere)


Using the deepest X-ray image ever taken, astronomers found the first direct evidence that massive black holes were common in the early universe. This discovery from NASA's Chandra X-ray Observatory shows that very young black holes grew more aggressively than previously thought, in tandem with the growth of their host galaxies.

By pointing Chandra at a patch of sky for more than six weeks, astronomers obtained what is known as the Chandra Deep Field South (CDFS). When combined with very deep optical and infrared images from NASA's Hubble Space Telescope, the new Chandra data allowed astronomers to search for black holes in 200 distant galaxies, from when the universe was between about 800 million to 950 million years old.

"Until now, we had no idea what the black holes in these early galaxies were doing, or if they even existed," said Ezequiel Treister of the University of Hawaii, lead author of the study appearing in the June 16 issue of the journal Nature. "Now we know they are there, and they are growing like gangbusters."

neilzero
2011-Jun-20, 09:33 PM
Since very massive black holes take billions of years to loose significant mass, 10%? of them should still be within a few billion light years of our present location. Still growing even more massive is more probable. Neil

Shaula
2011-Jun-20, 10:04 PM
10%? What of every BH in the universe? Or of the ones formed in the expanding pocket of space near us? How big a pocket? Where did you get 10% from?

Cougar
2011-Jun-22, 01:25 PM
the new Chandra data allowed astronomers to search for black holes in 200 distant galaxies, from when the universe was between about 800 million to 950 million years old.


I noticed the oldest quasar in the SDSS was at a redshift of 6.9995, when the universe was about 778 million years old. The longstanding question about early structure formation seems to be getting answered....

thritham
2011-Jul-05, 02:58 PM
Is it possible that all super massive BH were formed in the early universe (abudance of hydrogen lead to super massive stars collapsing quickly into SMBH) and that these SMBH 'shaped' all remaining material/stars into the galaxies that we can see today?

Shaula
2011-Jul-05, 06:13 PM
Population III stars are thought to have been up to a few hundred times the mass of the Sun. SMBH can be a few billion times the mass of the Sun. The largest stars thought to have formed can not have formed SMBH on their own. Whatever happens you need mergers and therefore time.

loglo
2011-Jul-05, 08:08 PM
Is it possible that all super massive BH were formed in the early universe (abudance of hydrogen lead to super massive stars collapsing quickly into SMBH) and that these SMBH 'shaped' all remaining material/stars into the galaxies that we can see today?

There is the "Direct Collapse" scenario where SMBH are formed directly from collapsing clouds of gas. This paper (http://arxiv.org/abs/1007.4741) discusses it as one of two main models being considered. The favoured model is as Shaula described though both have unresolved issues.

borman
2011-Jul-06, 02:14 AM
There seems to be a time problem if all these early SMBHs need to form from smaller stellar black holes falling into each other if the universe is only so old.

Perhaps a way out is to consider an alternative way to form a closed surface other than collapse. Try expansion to form a SuperMassiveBlackSphere. This would correlate with the formation of the cuspy hole within the proposed halos that surround galaxies as well as the seeming relationship between the mass of the SMBS and the inner mass volume of galaxies.

The mechanism would assume, at early galaxy formation, that the surface density in the core has not yet reached a threshold value that exceeds the a_0 of the MOND idea. Then even in the core, the dark matter effect with gas and stars moving faster than accountable for by Newton's laws, governs their motion. When the galaxy accretes enough mass, the threshold is exceeded and Newton only takes over. However the stars and gas still have an excessive radial component that is not held in check by Newton. The effect is like spinning a ball at the end of a tether and suddenly releasing the tether whereupon the ball moves on out radially. As the inner mass moves out, it then affects the local surface density. Eventually the density will increase to a threshold that will close the surface, a sphere in this case rather than a hole. Viewed from the outside, it would be difficult to discern whether the closed surface is either a black hole or a black sphere.

Shaula
2011-Jul-06, 05:04 AM
Citations for the idea? Sounds non-mainstream to me. And unphysical. But that might just be an artefact of putting it into words. What mechanism causes the expansion?

thritham
2011-Jul-06, 06:40 AM
@loglo - am reading the paper you referred to and need to understand the meaning of "redshift Z=6" when referring to SMBHs as massive as several billion solar masses. Help...

borman
2011-Jul-08, 11:24 PM
Citations for the idea? Sounds non-mainstream to me. And unphysical. But that might just be an artefact of putting it into words. What mechanism causes the expansion?

Indeed, Einstein thought black holes were unphysical, but he was not able to come up with a NO-GO theorem that forbade their existence. They are at least theoretically allowed in General Relativity. Over the past decades, astronomers have been finding mass concentrations that appear to be candidate black holes where alternatives have not succeeded in surviving, i.e., neutron stars get ruled out.

Mathematically, it should make no difference whether the singularity occurs from the inside-out in the slower forming sphere or the much faster outside-in compression due to supernova or hyperova.

The mechanism is conservation of momentum.

As initial conditions assume a Low Surface Brightness (LSB) galaxy or dwarf galaxy where the Dark Matter Effect penerates to the very core and all the stars are then rotating faster than would be expected of Newton's dynamics and furthur assume that the surface density is such that the acceleration is on the verge of being greater than the a_0. Then either accrete more mass or assume a hyper velocity star traces across pockets where the critical value can be exceeded. Newton's laws then come in force in these pockets and, obeying momentum coservation, these stars fly off only to disturb other near critical pockets. This somewhat reminds one of a fusion reaction where the flow is outward forming a spheical surface from the inside -out. Eventually the surface density can grow to close the surface where the total mass of the sphere might be millions or even billions of solar masses before closure.

As to citation, Einstein wrote the General Relativity Theory.

borman
2011-Jul-08, 11:33 PM
To provide balance

There were two papers today on the arXiv by the same team that look to cold flows into already existing SMBH. This may be “kicking the can down the road” or a viable solution alternative:

Cold flows and the first quasars
http://arxiv.org/abs/1107.1253

Early Black Holes in Cosmological Simulations: Luminosity Functions and Clustering Behaviour

http://arxiv.org/abs/1107.1254

loglo
2011-Jul-09, 01:04 AM
@loglo - am reading the paper you referred to and need to understand the meaning of "redshift Z=6" when referring to SMBHs as massive as several billion solar masses. Help...

"z" is the cosmological redshift factor. Used in the context of a galaxy at z=6 we are seeing that galaxy as it was 12.8 billion years ago when the universe was less than a billion years old. The light's wavelength has stretched by a factor of 6 as the universe expanded during its travels. So the paper tries to explain the existence of SMBH less than a billion years after the Big Bang.

Here is a handy page (http://www.wolframalpha.com/input/?i=redshift+z%3D6&a=FSelect_**LookbackTimeFromRedshift--) to calculate redshift.

Shaula
2011-Jul-09, 06:21 AM
As to citation, Einstein wrote the General Relativity Theory.
And what you are describing is not just GR. Dark matter is from the LCDM model or its ilk. You said that mathematically it should make no difference. I believe it does. I also believe that getting so many star in such a small volume would basically result in most of them being ejected. Please show how so many stable orbits can be crammed into this area. Please also link to a peer reviewed paper that discussed this mechanism for super massive black hole formation. If there is not one then it should not be a part of this thread as this is a thread to discuss mainstream work and theories.

borman
2011-Jul-09, 05:15 PM
You said that mathematically it should make no difference. I believe it does.
Can you prove this either yourself or cite a reference or a NO-GO thoerem that spcifically prohibits closing a surface from the inside out. I am not aware of one but will look at any reference you submit. Belief is not a substitute for proof.

Shaula
2011-Jul-09, 05:57 PM
Mathematically, it should make no difference whether the singularity occurs from the inside-out in the slower forming sphere or the much faster outside-in compression due to supernova or hyperova.
Was what you said. Please show me how it makes no difference. Full GR treatment please. I'm not even sure I understand fully what you mean by closing a sphere from the outside. Do you mean that one perturbation causes a system to collapse? You seem to be envisioning a system on the very edge of collapse that is triggered to collapse by an external perturbation? Which seems an implausible set of initial conditions. Why would this happen so often that every galaxy has a SMBH in it?

I'm trying to put across the mainstream - I am asking you to show how your theory is mainstream. It is not up to me to prove that it is not! So, please, you prove that it doesn't make a difference so we can all understand exactly what you mean.

parejkoj
2011-Jul-09, 06:55 PM
For a summary of some of the formation mechanisms for supermassive black holes in the early universe, see Volonteri (2010) (http://adsabs.harvard.edu/cgi-bin/bib_query?arXiv:1003.4404), which discusses the best current research on the topic.

borman
2011-Jul-09, 09:13 PM
Shaula,
I believe my idea actually is mainstream. Had you presented a NO-GO thoerem, you would have falsified GR.

It is because of the considerations regarding the correlations between the mass of the SMBH and the host bulge from parejkoj's cite that generates the idea so long as one remembers that the velocity of stars in a Dark Matter dominated region is related to the 4th power of the total mass. The greater the mass of the pre-SMBH host bulge, the faster the internal stars are rotating, and hence the greater is their angular momentum. When the force that governs this high speed is cut by exceeding a threshold acceleration, the stars will fly way from the center of mass much as a rotating ball would fly away if the string is released. The collapse isn't from the outside-in such as how a stellar black hole forms. Rather the mass within the volume of a sphere moves outward to then interfere with other pockets not yet above the threshold. The surface continues to accrete mass by expanding until a critical density is reached that closes the surface forming a black sphere. The correlation between the mass of the SMBH and the host bulge is then via the 4th power velocity relation.

Shaula
2011-Jul-09, 09:35 PM
Citation. Please. Your idea sounds contrary to the accepted models. If it is purely your idea then it needs to be tested and validated by peer review. If not then please point me at who's idea it is and how they formulated it. You seem to be invoking a form of MOND? IS that what you mean by the force changing beyond a cut off point?

borman
2011-Jul-09, 10:50 PM
What accepted model? The reason this is news at all is because theorists do not have an accepted model. Instead they have headaches and restless nights ahead to try to either discover or make one up.

I don't have a citation on closure from the inside but it could have been written anytime after 1916 and most likely considered in the early 1920's. While unusually high galaxy speeds were noted by Zwicky, that of stars in a galaxy only goes back as far as Vera Rubin in the 1970's. The particular relation between luminous mass and speed of stars is generally known as the Fisher-Tully relation. The MOND papers I believe start with 1983. It is not derived from first principles but is a phenomenolgical theory intended to explain the actual observations of astronomers. Whether or not one thinks MOND is right does not allow one to dismiss the facts of observation.

At present no one has observed the formation of a SMBH. Astronomers will need to look even further back to see most of the early ones forming. Meanwhile, they can continue to search for candidate galaxies that do not yet have a SMBH and monitor for SMBH formation.

As for the present simple idea, I am reluctant to take credit for an idea that any of thousands could have come up with in the past quarter century.

Shaula
2011-Jul-10, 06:32 AM
So it is your idea, unsupported by anything peer reviewed and not backed by anything like a rigorous mathematical model consistent with the current models of how the universe evolved. I just wanted to make sure that this point was clear so that anyone browsing this thread can clearly and easily discriminate the different levels of validation and testing applied to the theories presented.

Mainstream: Modelled mathematically, tested to show it is in broad agreement with most objects seen. Continually refined to fit new observations like this one. Backed by a lot of published work and fits into a greater framework of 'how we think things work'. Currently mainstream. Believed to have an issue with this observation but fits many others.

Your model: No maths, no tests, first draft based on selected observations and not validated against anything more than a tiny data set (possibly one). At first glance not compatible with how we think things work (but this cannot be said for sure due to the lack of peer review). Currently speculation. May possibly (again, see untested unvalidated bit) explain this one observation if put on a sufficiently rigorous mathematical foot - but this is currently not the case.

I have no issues with other theories but feel that in the interests of intellectual rigour and honesty their full status must always be made clear. Otherwise it can be misleading. I in no way imply that this is due to nefarious intent on you part, by the way. Anyone who is a fan of a theory tends to present it as the right solution. Which gets confusing.

borman
2011-Jul-10, 01:59 PM
Mainstream: Modelled mathematically, tested to show it is in broad agreement with most objects seen. Continually refined to fit new observations like this one. Backed by a lot of published work and fits into a greater framework of 'how we think things work'. Currently mainstream. Believed to have an issue with this observation but fits many others.



Again, I ask what "mainstream" model you are talking about? What mainstream theory claims to show how a SMBH forms? This was probably one of the first questions asked shortly after SMBH were invoked to exist. But it has remained an open and unresolved problem, as far as I know. The problem is not just recent but has been around since the existence of SMBHs have been invoked. There is not enough time for stellar black holes, even those of the larger Pop III stars, to coalesce and still hope to remain consistent with mainstream cosmological theory. The new observations of CHANDRA only renew and refresh this old problem with the addition that the time problem is now even more severe as their formation dates are moved back even further.

If you want to invoke intellectual rigour and honesty, then by all means you should cite the proposed, peer-reviewed, mainstream theory that demonstrates how SMBHs form.

For my part, if mainstream has not resolved the problem after decades of trying, it may be time to consider possible alternatives to collapse that do not violate GR.

parejkoj
2011-Jul-10, 02:42 PM
... by all means you should cite the proposed, peer-reviewed, mainstream theory that demonstrates how SMBHs form.

I just did. Volonteri (2010) lists several possible formation mechanisms, all of which are fully consistent with lambda-CDM, and which can work in the required short amount of time. The trick now is distinguishing between them, and she also provides a variety of ways to do so, several of which are currently under study.

Nereid
2011-Jul-10, 02:57 PM
borman, did you read Volonteri (2010)? What questions do you have about the mechanisms presented therein?

If you have read it, and do not have any questions, what objections (if they may be called that) do you still have?

Shaula
2011-Jul-10, 04:49 PM
What they said.

The broad sweep of the mainstream ideas (those that invoke collapse, are consistent with mainstream cosmology etc) is in pretty good agreement with observations AIUI. There is no need to propose that black holes form from the inside out.

PS. If you want to defence your idea and prove that it doesn't violate GR then provide a reference for it or take it to ATM. This is not a forum to propose these sorts of new ideas.

borman
2011-Jul-10, 09:11 PM
borman, did you read Volonteri (2010)? What questions do you have about the mechanisms presented therein?

If you have read it, and do not have any questions, what objections (if they may be called that) do you still have?

From the introduction of Volonteri (2010):

“Dynamical estimates indicate that, across a wide range, the central black hole mass is about 0.1% of the spheroidal component of the host galaxy (Magorrian et al, 1998; Marconi and Hunt, 2003; Haring and Rix, 2004). A tight correlation is also observed between the MBH mass and the stellar velocity dispersion of the hot stellar component (Ferrarese and Merritt, 2000; Gebhardt et al, 2000; Tremaine et al, 2002; Gultekin et al, 2009). The surprisingly clear correlations between MBH masses and the properties of their host galaxies suggest a single mechanism for assembling MBHs and forming galaxies. The evidence therefore favors a common root, a co-evolution, between galaxies and MBHs. These correlations may well extend down to the smallest masses. For example, the dwarf Seyfert 1 galaxy POX 52 is thought to contain a MBH of mass MBH _ 105M_ (Barth et al, 2004).”

This is what we know from observations and empirical deductions. The correlations are useful in particular because they suggest constraints. A viable theory should explain all the correlations. It should also try to explain how some galaxies do not have a SMBH.

I have no problem accepting these observations. They are in line with my own hypothesis. This is especially true of the tight correlation between the mass of the SMBH and the observed stellar velocity dispersion (Tully-Fisher relation).

The first correlation is general, but the requirement of a spheroidal component in addition to velocity dispersion is not universal:
An actively accreting massive black hole in the dwarf starburst galaxy Henize 2-10
http://www.nature.com/nature/journal/v470/n7332/full/nature09724.html

But supernova driven winds can deplete some bulge gas:

Bulgeless dwarf galaxies and dark matter cores from supernova-driven outflows
http://www.nature.com/nature/journal/v463/n7278/abs/nature08640.html



Regarding non-correlation of Dark Matter Halos:
Supermassive black holes do not correlate with dark matter haloes of galaxies
http://www.nature.com/nature/journal/v469/n7330/full/nature09695.html

Pseudobulges and disks:
Supermassive black holes do not correlate with galaxy disks or pseudobulges
http://www.nature.com/nature/journal/v469/n7330/full/nature09694.html

Although a small sample, an apparent correlation to globular clusters:
A correlation between central supermassive black holes and the globular cluster systems of early-type galaxies
http://arxiv.org/abs/1004.0137

Press report from physicsworld:
Supermassive black holes reveal a surprising clue
http://physicsworld.com/cws/article/news/42693

This study needs to be expanded to a larger sample size to see if the surprising relation continues to hold or if it might be a remarkable statistical fluke.

Volonteri (2010):

“It is likely, however, that if the forming black hole is too light, it will not be dynamically stable within the center of its host, once stars populate a galaxy. A light black hole might wander within its host, dynamically interacting with stars of similar mass, rather than settling at the center of the galaxy's potential well.”

This somehow reminds me of cartoon physics. Even though a star can collapse to a black hole with the occasional random direction kick, it does not lose its orbital angular momentum and suddenly fall to the center of the potential well. From a distance it will behave like a star and stay in orbit. Only close to the black hole will tidal effects show themselves.

Volonteri (2010):

“We do not know if PopIII stars are indeed very massive, and in particular if they are above the threshold (' 260M_) for MBH formation.”
See from Nature:
Direct formation of supermassive black holes via multi-scale gas inflows in galaxy mergers
http://www.nature.com/nature/journal/v466/n7310/full/nature09294.html

They state in the abstract that:
“Models in which the ‘seeds’ of such black holes form by the collapse of primordial metal-free stars2, 3 cannot explain the rapid appearance of these supermassive black holes because gas accretion is not sufficiently efficient4, 5, 6.”

But then how is their idea going to be consistent with the tight correlation seen between host star velocity and SMBH mass if proto galaxy mergers are the cause of formation? There should be no correlation unless purely accidental every time.

This is brought up in this Science abstract:

Major Galaxy Mergers and the Growth of Supermassive Black Holes in Quasars
http://www.sciencemag.org/content/328/5978/600.abstract?sid=d9663577-0635-4bd8-ac1f-7e3dc938339a

“Despite observed strong correlations between central supermassive black holes (SMBHs) and star formation in galactic nuclei, uncertainties exist in our understanding of their coupling.”

So, if we disregard strong correlations, mergers could be a viable source for SMBH. But then how does the correlation come about that is being disregarded?

Also from Volonteri in Nature:
Astrophysics: Making black holes from scratch
http://www.nature.com/nature/journal/v466/n7310/full/4661049a.html

“The means by which supermassive black holes form and grow have remained largely unclear.”

If, before merger, they both already have a SMBH, a binary appears more probable:
Rapid Formation of Supermassive Black Hole Binaries in Galaxy Mergers with Gas
http://www.sciencemag.org/content/316/5833/1874.abstract?sid=d9663577-0635-4bd8-ac1f-7e3dc938339a


Volonteri (2010):

“In a typical high-redshift galaxy with Tvir _
 104K (Mh _ 108 M_; rvir _ 500 pc) the tidally induced angular momentum would therefore be enough to provide centrifugal support at a distance ' 20 pc from the center, and halt collapse, ultimately leading to the formation of a disk. Additional mechanisms inducing transport of angular momentum are needed to further condense the gas until conditions fostering MBH formation are achieved.”

Here again, angular momentum is working against SMBH formation. It needs to be “drained off” via some mechanism.
As various candidate mechanisms are explored, each imposes constraints that would limit which galaxies could form SMBH. For example, bars could transport the momentum, but then do only galaxies with bars have SMBH? Constraints like these make it less likely that galaxies can have SMBHs, but in fact many do. The unexplained mystery is how some galaxies actually do avoid having a SMBH. This is an important clue to understanding how most of the other galaxies do have SMBHs.

Likewise, while mergers can better lead to seeds, does this mean that no galaxies that avoided mergers can have a SMBH?

The point is that as more particular constraints are brought into play, this cuts down on the overall proportion of galaxies that can have a SMBH. But in her introduction, the correlations suggest a common co-evolution between galaxies and their SMBH that would argue against special conditions to form seeds not uniformly evident in all galaxies. Perhaps the context for seed formation could be accumulative meaning if they did not form one, then they formed another. However this has to be tempered with the requirement that all seeding mechanisms need to end up reproducing the observed correlations. I do not see the full connection from proposed seed formation to the recapture of the observed correlations in this paper. Perhaps that will be the subject of a future paper.

From the conclusion of Volonteri (2010):
“The early evolution of MBHs, and most notably, what physical mechanism is responsible for their formation are however still unknown. We now do know that MBHs are there, but we do not know how they got there. “

“In this article I focused on three plausible mechanisms of MBH seed formation.”

The trick is to recapture and preserve the correlations, which is the actual information we do have at present, to connect the seeds to what we see in the tightly constrained allotted time allowed by the CHANDRA observations.

Also it is important to develop criteria to explain how many, but not all, even nearby (z=0) dwarf galaxies do not have SMBH. For example, is a cuspy hole in the halo needed for SMBH? Is there a threshold regarding velocity dispersions suggesting that below a critical velocity, SMBHs do not form?

The mechanism I suggested in the absence of any unequivocal known mechanism, according to Volonteri’s conclusion, can readily be falsified by observing a SMBH in a galaxy where the acceleration everywhere to the core is comfortably below the MOND a_0.

Shaula
2011-Jul-10, 09:32 PM
So in essence you are saying "Oh, there are questions still to be answered. That means that my speculations are just as valid as the current models."

Publish your idea. Get it out there, get it tested and get it validated. Without peer review it is no more valid than the nangnomes theory.

borman
2011-Jul-10, 09:48 PM
I merely asked you to cite the mainstream theory that shows how SMBH form. According to the conclusions of Volonteri, no such theory yet exists.

Shaula
2011-Jul-10, 10:15 PM
And I asked you to cite any published work exploring your speculation. Volonteri et al - you might want to read the paragraph after the bit you quoted. It is perfectly clear that there are several theories for SMBH formation that cannot be told apart. but common to all of them is coalescence. You have been given a nice summary of the mainstream model. Note that the underlying mechanism is the same in all of them - this is the mainstream I have been talking about. The unknowns lie in the details of how this happened, seed size and so on. You are presenting a whole new mechanism for black hole formation. Which is why it needs to have citations and peer review. The merger mechanism is valid - yours has not been shown to be.

So please, I ask you again. What published work backs your speculation?

neilzero
2011-Jul-20, 01:39 AM
10%? What of every BH in the universe? Or of the ones formed in the expanding pocket of space near us? How big a pocket? Where did you get 10% from?
I picked a number; I have a need to do that, just as many posters don't even infer that many is less than a google = 10E100. I did put a question mark, hoping someone would tell me 0.2% within 4,000,000,000 light years or 30% within 12 billion light years.
Likely some = 75%? of the black holes we view 13 billion light years away, are presently beyond the limits of our visable universe. Think much (trillion times?) faster than light speed and where the SMBH would be if we traveled to that pocket. Forgive me if my understanding is flawed. Neil

Shaula
2011-Jul-20, 05:19 AM
I picked a number; I have a need to do that, just as many posters don't even infer that many is less than a google = 10E100. I did put a question mark, hoping someone would tell me 0.2% within 4,000,000,000 light years or 30% within 12 billion light years.
Likely some = 75%? of the black holes we view 13 billion light years away, are presently beyond the limits of our visable universe. Think much (trillion times?) faster than light speed and where the SMBH would be if we traveled to that pocket. Forgive me if my understanding is flawed. Neil
The problem with just picking numbers is that it is meaningless. You stated that 10% of the would still be near us which seems to imply you think 90% of them would have evaporated. Which is counter the prevailing view and models unless you assume a large population of small black holes form near the Big Bang. This is a science board and it is kind of expected that answers will have some sort of science to back them up. Just making stuff up is not an acceptable way to derive an answer, for me. So I challenge answers that look like they are plucked from thin air. Speaking of which - where did you derive 75% from? What justification do you have for that figure?

neilzero
2011-Jul-22, 12:07 AM
I stand reproved. I think I understand why you don't want these treads filled with wild guess numbers, lest some one take an average and be deceived. Is the following acceptable? Since these alleged SMBH were found about 13 billion light years from Earth; it is reasonable to assume many of them are not close by at present, even though the Universe has expanded enormously in the past 13 billion years, which is sort of:naughty: different than 13 billion light-years? Neil

luluxiu
2011-Aug-01, 12:19 AM
I also believe that in such a small volume, so much so that star will basically result in the majority, they are ejected. Please show how much stable orbits can be packed into the field...