Hydro-gravitational-dynamics (HGD) cosmology suggests that hierarchical clustering began at 10^12 s after the Big Bang, at matter radiation equality, and proceeded from the top down at the Schwarz viscous scale, progressively fragmenting the plasma realm into smaller and smaller clumps, beginning at the supercluster-scale and progressing to the cluster-scale and finally the galaxy-scale prior to the epoch of recombination. At recombination, Jeans instability was able to operate for the first time, fragmenting proto-galaxies into million solar mass proto-globular-clusters. (Gibson 2006)
Baryonic dark matter (DM) cosmology suggests baryonic DM reservoirs in the form of self-gravitating planetary-mass globules of gas in hydrostatic equilibrium, that are a few astronomical units across. These baryonic DM globules are designated ‘paleons’ by Manly Astrophysics for their presumed old age. The evidence for paleons comes from scintillation of pulsars and quasars by foreground plasma entities, which can have been modeled as paleons with ionized outer shells, which are ionized by plowing through interstellar gas at 230 km/s in their rotation around the Milky Way.
Paleons are suggested to have to have been ejected from Population III protostars during magnetic connection chain reactions, which progressed around the equator at the rate of the magnetic-reconnection shockwave, unzipping equatorial material which was magnetically condensed into self-gravitating paleons. A similar process is suggested to occur today in the form of self-gravitating, planetary-mass cometary-knot (CK) ejection from late-stage asymptotic giant branch (AGB) stars, mirroring conditions in the early universe.
ΛCDM cosmology is particularly robust in its evidence from the epochs of nucleosynthesis and recombination, but this standard model of cosmology is comparatively weak in its reliance on hierarchical clustering for the formation of structure in the universe, notably with the missing satellite problem of large galaxies, and the discovery of supermassive-black-hole quasars earlier than z = 6.
Additionally, dark matter (DM) concentrations in galaxy cores do not conform to models predicting a cuspy concentration, known as the ‘cuspy halo problem’, and the complete absence of DM in globular clusters requires secondary mechanisms to explain away its absence. Alternatively, baryonic DM that converts to stars and luminous gas in regions of high stellar density is predictive, by comparison.
Structure formation by hydro-gravitational-dynamics (HGD) in the plasma epoch suggests that proto-spiral-galaxies formed by turbulent fragmentation, with the angular momentum of spiral galaxies naturally arising from eddy current vortices in the turbulence. While hierarchical clustering may neatly explain the origin of dwarf spheroidal galaxies and the merger of giant spiral galaxies to form giant elliptical galaxies, it has no intrinsic mechanism for the origin of the typical angular momentum of spiral galaxies.
Pulsar and radio galaxy scintillation provide evidence for self-gravitating gaseous globules, designated ‘paleons’ by Manly Astrophysics, which provides hope of actual DM detection, rather than its mere gravitational influence.
Finally, the evidence of planetary-mass ‘cometary knots’ in planetary nebulae today suggest a formation mechanism which is extended to the suggested formation of their primordial paleon cousins in the early universe.
Alternative hydro-gravitational-dynamics (HGD) cosmology:
The standard model ΛCDM cosmology of cold dark matter hierarchical clustering (CDMHC) for self-gravitational structure formation is predicated on the 1902 Jeans criterion for gravitational instability, which neglects viscosity, diffusivity, and turbulence and which sets density to zero (the Jeans swindle) to derive the Jeans length scale. CDMHC suggests that hierarchical clustering only began after the epoch of recombination at 10^13 s, with gravitational structure formation proceeding from the bottom up, with small structures forming first and large structures forming last.
When viscosity, diffusion and turbulence are included in the analysis, HGD cosmology suggests that gravitational fragmentation proceeded from the top down at the Schwarz viscous scale, with the supercluster-scale fragmentation initiated 10^12 s after the Big Bang at matter radiation equality, followed by cluster-scale and galaxy-scale fragmentation in the plasma realm prior to the epoch of recombination.
HGD cosmology suggests HGD structure formation in the plasma epoch, between 10^12 to 10^13 seconds after the Big Bang, followed by Jeans instability at the epoch of recombination on the scale of circa million solar mass ‘proto-globular-clusters’.
Cometary knot (CK) formation by ‘magnetic-reconnection unzipping’ in AGB stars:
Thousands of cometary knots stream out from the stellar remnant in the Helix planetary nebula (NGC 7293) in a system where “the central star is about 6560 yr into its life as a star nearly liberated of its envelope.” (Capriotti and Kendall 2006) O’Dell and Handron (1996) give the density, mass and size of the neutral gas in the estimated 3500 cometary knots of the Helix nebula as, hydrogen density ~ 4 x 10^6 cm-3, with a mass range of ~ 4 x 10^25 to 4 x 10^26 g and radii of 60–200 AU, based on the distance to the nebula of 213 pc. CKs have bright rims facing the central star and cometary tails trailing away, caused by photoevaporation by the brilliant white-dwarf remnant.
The main body of the nebula is an inner ring, roughly 500″ (0.52 pc) in diameter surrounded by a highly-inclined torus of 740″ (0.77 pc) diameter, with an outermost ring 1500″ (1.76 pc) in diameter. The CKs near the inner edge of the inner ring are traveling away from the central star, along with the ring material in which they are embedded. O’Dell et al. (2004) estimate an expansion age for the inner ring of 6560 yr, using an expansion velocity of 40 km/s and a present radius of 0.26 pc, at a distance of 213 pc. In the interior of the inner ring, but not closer than 120″, CKs dominate the landscape, while beyond 190″, large clouds do, although, while the CKs in the inner ring are the most prominent, infrared observations have detected CKs in regions outside the inner ring in numbers a factor of 6 or so greater than the inner ring. The inner ring is the last of three major ejections, 6560 years into its life as a small hot very luminous star nearly liberated of its envelope. (Capriotti and Kendall 2006)
This symmetry approach, which attempts to equate modern CKs with primordial paleons, makes two assumptions; that CKs are self gravitating like paleons, and that no self-gravitating objects can form by direct collapse which are smaller than a Jeans mass, which suggests that CKs are ejected from the star itself.
After helium runs out in the stellar core it continues to burn in a thin shell surrounding the core during the early (E-AGB) phase. After the helium in the shell is depleted, the thermally pulsing (TP-AGB) phase starts. The star now derives its energy from burning a thin shell of hydrogen which accumulates a thin shell of helium which ignites explosively in a process known as a helium shell flash. The helium shell flash causes the star to temporarily expand and brighten, puffing up the star which lowers its temperature, extinguishing hydrogen fusion. The helium shell flash also induces convection (third dredge-up) which brings carbon from the core to the surface and also mixes hydrogen from the surface into deeper layers where it reinitializes hydrogen fusion to begin another thermally pulsing cycle.
The rapid helium shell flash lasts only a few hundred years in the life of a thermally pulsing cycle, where one cycle runs from 10,000 to 100,000 years. Our Sun may only undergo four 100,000 year thermally pulsing cycles before it’s successful in throwing off its outer layers to expose its core as a white dwarf. More massive stars, by comparison, may undergo many more closer-spaced thermally pulsing cycles than our Sun before fully ejecting their outer layers to reveal a degenerate white-dwarf core in the planetary-nebula end game.
As the outer layers of a star expand following a helium shell flash, the magnetic field locked into the plasma attempts to enforce solid rotation, despite the thermally-pulsing expansion which increases the moment of inertia of the star. If the magnetic corotation radius is forced below the surface of the star during an expansion phase, the magnetic field becomes twisted at this radius. When the magnetic field becomes twisted to the breaking point at the magnetic corotation radius, a spontaneous occurrence of magnetic reconnection may create a rebound shockwave which sets off a chain reaction of magnetic reconnection events which propagate around the equator, unzipping the outer layer of the star to form one or perhaps to form many sibling CKs.
If magnetic field lines became twisted in a symmetrical fashion at the magnetic corotation radius, the spontaneous release of magnetic energy by magnetic reconnection would create a rebound shockwave, and if the rebound shockwave were able to push the adjacent magnetic field past the breaking point, then a magnetic-reconnection chain reaction might ensue.
The suggested shockwave-triggered chain reaction likely progresses in only one direction, either clockwise or counterclockwise around the equator, since the shockwave would tend to reduce the magnetic tension in one direction while increasing the tension in the other direction. The chain reaction propagates at the speed of the shockwave around the star, stripping off a layer around the equator in a process we’ll designate, ‘magnetic-reconnection unzipping’. In reality, the magnetic-reconnection unzipping is unlikely to progress anywhere near 360° around the star in a single event, but successive unzipping events are likely to be closely-spaced like machine gun fire.
The magnetic field in the ejected plasmoid unzipping will cause the plasma to tend to clump into one or more globules which cool to form CKs, where gravity only becomes significant after recombination into neutral hydrogen and helium.
While CK ejection likely occurs in each of a succession of thermally-pulsing AGB cycles, perhaps only those in the final cycle or final cycle and final cycle but one are illuminated in the subsequent planetary nebula phase. And since a large percentage of stars are intermediate mass (0.6–10 solar masses), which pass through an asymptotic giant branch phase, Population II and I stars may make a significant contribution back to the DM realm.
So if intense stellar radiation evaporates paleons, and evaporated gas collects to form giant molecular clouds, and giant molecular clouds condense predominantly intermediate mass stars, and intermediate-mass stars may return a majority of their mass back to the dark matter realm, then intermediate-mass stars may be efficient galactic recyclers.
Fragmentation at recombination:
In the plasma epoch prior to recombination, the Jeans scale exceeded the horizon scale, precluding gravitational fragmentation by the Jeans mechanism, due to the high speed of sound in plasma (on the order of the speed of light). At the epoch of recombination, the Jeans scale of neutral gas was on the order of 1 million solar masses, promoting gravitational collapse of the neutral continuum into proto-globular-cluster-scale masses. (Gibson 2006)
Gibson suggests that HGD caused fragmentation into self-gravitating earth-mass ‘primordial fog particles’ (PFP) at the epoch of recombination, and that the PFPs have subsequently condensed to form earth-mass ‘Jovian planets’ (presumably designated ‘Jovian planets’ for their hydrogen-helium composition). And since the Jeans scale at recombination was on the order of one million solar masses, these PFPs were clumped into proto-globular clusters. These persistent Jovian planets constitute baryonic dark matter, explaining the missing baryon problem as 30,000,000 earth-mass rogue planets per star in the Galaxy. Additionally, Gibson replaces dark energy with hot dark matter, such as neutrinos, which are only become significant in gravitational clumping at the galactic cluster scale.
We agree with fragmentation of the continuum at recombination into proto-globular-clusters, but dispute the HGD sub-fragmentation into primordial fog particles, whether or not they would have condensed into Earth-mass Jovian planets as suggested; however, extreme scattering events of pulsars appear to indicate baryonic DM reservoirs in self-gravitating, gaseous globules in hydrostatic equilibrium on a scale of 1 AU or larger, rather than condensed Jovian-planets. We suggest an alternative Population III protostar origin for self-gravitating paleons to that of HGD fragmentation at recombination.
Paleons formation in proto Population III stars by magnetic-reconnection unzipping:
Physical symmetry between CKs and paleons suggests formational symmetry, albeit with much greater efficiency in the formation of primordial paleons. Globular clusters are marvels of stellar concentrations, which have efficiently converted gas into stars, so by extension, it’s not unnatural to suspect that the great efficiency of paleon formation may be similarly tied to fragmentation of the neutral continuum at recombination into circa million solar mass proto-globular-clusters.
Continued expansive cooling of the universe promoted sub-fragmentation of proto-globular-clusters, where the sub-fragmentation size is suggested to have been in the range of multi-thousand solar mass globules. Population III stars are suggested to have formed before sub-fragmentations could sub-sub-fragment into still-smaller globules, creating stars with the familiar initial mass function range of Population I & II stars.
Presumably multi-thousand-solar-mass sub-fragmentation globules were in continual hydrostatic equilibrium during ‘freefall’ collapse, with the contraction rate controlled by the exponentially-decreasing ambient temperature of the universe. At some point the hydrostatic contraction rate controlled by the ambient temperature of the universe became slower than the gravitational freefall rate, precluding any further gravitational sub-sub-fragmentations.
In a world with turbulence, simple hydrostatic contraction is the exception, with the norm resulting in a much more massive envelope, partially supported by rotation, surrounding a diminutive core. When the overlying envelope is much more massive than the diminutive core, the system is suggested here to be unstable and susceptible to disk instability, with disk instability occurring by the suggested mechanism of ‘flip-flop fragmentation’ (FFF), as a mechanism for catastrophically projecting mass inward.
When a much more massive envelope, partially supported by rotation, surrounds a diminutive core and the diminutive core-to-envelope mass is insufficient to dampen out inhomogeneities in the envelope, the envelope will tend to undergo runaway disk instability, causing it to catastrophically clump to form a larger central mass, which inertially displaces the former core into a satellite status. This is the mechanism which is suggested to ‘spin off’ former diminutive cores as gas/ice giant planets.
So what might otherwise be a gradual hydrostatic contraction without rotation becomes freefall collapse of a envelope to form a new larger core as an emerging Pop III protostar. A contracting multi-thousand-solar-mass globule may have to undergo repeated episodes of FFF to spin off sufficient angular momentum to finally achieve sufficient mass with sufficiently little specific angular momentum to form a Pop III protostar capable of undergoing repeated episodes of magnetic-reconnection unzipping.
Freefall contraction of an envelope to form a new core causes spin up, which likewise increases the rotation rate of the protostar magnetic field. And contraction causes heating, with an ionization front moving outward from the contracting core. When the magnetic corotation radius drops below the outward-moving ionization front, the magnetic field lags the core, which twists the field, building up magnetic energy.
When the magnetic field becomes twisted to the breaking point at the magnetic corotation radius, a spontaneous occurrence of magnetic recombination is suggested to create a chain reaction of magnetic reconnection events in the form of a long series of magnetic-reconnection unzipping events which is suggested to reduce Pop III stars to the 160 to 250 solar mass range, ending in pair-instability supernovae which leave no stellar remnants, since there’s no evidence for zillions of Pop III remnants, in the form of white dwarfs, neutron stars or black holes. If magnetic-reconnection unzipping also restricts star formation today to the 130 to 250 solar mass range, then perhaps still-larger stars can only form by binary merger.
To have converted as much as 9/10 of all matter to (DM) paleons within a short time frame warrants an epoch designation, which is suggested as, ‘paleon epoch’, or ‘Population III star epoch’, and for such a high percentage of DM, the vast majority of matter of the universe must have been processed through Pop III protostars, even if only a small percentage of baryonic matter went on to become Pop III main sequence stars.
A modern CK with a radial velocity on the order of 10 km/s might travel considerably slower when escaping a multi-thousand-solar-mass Pop III star, and then it would have to fight the gravitational well of the proto-globular-cluster, so primordial paleons are presumed to been gravitationally bound within their birth proto-globular-clusters, regardless of their uncertain history since then.
So magnetic-reconnection unzipping, as the formation mechanism of paleons in Pop III protostars, suggests a single generation of gravitational fragmentation of proto-globular-clusters into multi-thousand-solar-mass gas globules. The globules in turn underwent one or more generations of flip-flop fragmentation to wind down excess angular momentum, where the freefall collapse during FFF created super-efficient magnetic-reconnection unzipping episodes which ejected some 90% of the total globule mass in the form of paleons. And presumably, Pop III stars exploded in pair-instability supernovae, leaving no stellar remnants.
Extreme Scattering Events (ESEs) are suggested to be caused by the refraction of quasar radio waves by the ionized surface of occulting paleons, where the paleon surface is ionized by the shock of plowing through interstellar gas at around 230 km/s in their orbit around the Milky Way core. Self-gravitating paleons are calculated to be on the order of a few AU across and in a number density of a few thousand per cubic parsec in the neighborhood of the Sun (Tuntsov, Walker et al. 2015). Alternatively, however, the same scintillation effect can be modeled by anisotropic plasma distributions, such as a plasma sheet seen edge on without any accompanying self-gravitating dark matter component. (Tuntsov and Walker 2015)
Paleons are suggested to be hydrostatic self-gravitating globules of gas in a mass range of ∼ 10-7 to ∼ 10-1 solar masses, which are calculated by Manly Astrophysics to be stabilized by condensation and sublimation of solid hydrogen (snowflakes), although the ambient temperature of the universe has only dropped below the condensation point of hydrogen some 2 billion years ago, or so, suggesting that stabilization by hydrogen snow is relatively recent. The ∼ 10-7 to 10-1 M☉ mass range is based on their theoretical stabilization by hydrogen snowflakes, rather than on observational evidence by extreme scattering events or interstellar scintillation.
But if paleons date from Pop III stars, then hydrogen snowflakes would have to be superfluous for their survival; however, if hydrogen condensation increases the stability of paleons, then perhaps the increased stability may be responsible for the discovery that galaxies today emit only about half as much light as galaxies emitted 2 billion years ago. Thus the advent of the ‘epoch of hydrogen condensation’ may have ushered in a new era of reduced star formation, giving rise to popular articles declaring that the universe is dying.
But the suggested sedimentation of hydrogen snowflakes in turn suggests the sedimentation sedimentation of acquired stellar metallicity in the form of dust and ice, tending to form a central mass. Hydrostatic objects like paleons, however, tend to oscillate like Jello, which might tend to form multiple central objects which would ultimately accrete into a central mass.
While paleons may have formed with Big Bang chemistry, they will have acquired a small degree of stellar metallicity contamination in 13 billion years of orbiting the Galaxy core, with distant galactic halo paleons having acquired little stellar metallicity compared to paleons of the disk plane. By comparison, CKs are formed with highly-elevated levels of stellar metallicity, so paleons/CKs may vary more widely in metallicity than stars themselves.
Imagine that a paleon/CK with the average metallicity of the Sun (Zsun = 0.0134) might have a Moon-mass central mass (‘paleon core’) if all the metallicity were condensed into a central mass. But while Moon-mass paleon cores may be average for Earth-mass paleons in the disk plane of the galaxy, the average metallicy in the galactic halo should be significantly lower, resulting in much smaller paleon cores in the Galactic halo, but still presumably much larger than Oort cloud comets. So if every paleon has a moon-sized paleon core, of various sizes, then moon-sized paleon cores could be almost as prevalent as comet-sized objects in the universe.
Paleons may act as effective sponges, grabbing dust, ice from the respective Oort clouds of stars in their orbits around the galactic core. Manly Astrophysics computes a paleon density in the stellar neighborhood of ∼ 104 pc−3, which suggests that thousands may be passing through the Sun’s gravitational sphere of influence at any one time. Thus each paleon core could absorb dust, ice and microbes from thousands of stars in their orbits around the Galactic core, with paleon atmospheres providing better protection from ionizing UV and X-ray radiation than from cosmic rays, perhaps making paleon cores the most prolific panspermia reservoirs in the universe, even if they make vastly better panspermia sponges than disseminators.
Finally, The question of whether or the extent to which paleons today tend to cluster in primordial proto-globular-clusters is unaddressed, although large diameter paleons with readily distortable shapes may be considerably stickier than nearly point-mass stars/planets/comets/etc., causing paleons to tend to clump together, compared to star clusters that tend to dissipate over time.
Flip-flop fragmetation galactic evolution:
HGD turbulence presumably instilled proto-spiral-galaxies with their specific angular momentum, or more likely with excess angular momentum that underwent galactic evolution to catastrophically project mass inward to create mature spiral galaxies, with their typical range of specific angular momentum.
Following recombination, Jeans instability is suggested to have fragmented proto-galaxies into circa million-solar-mass proto-globular-clusters, and the loss of hydrostatic radiation pressure at recombination promoted galactic evolution, promoting gravitational collapse of proto-galaxies to the point of Keplerian rotational support by angular momentum. Gravitational collapse during galactic evolution causes ‘spin up’, flattening evolving proto-galaxies into doughnut-shaped envelopes, rotating around their angular momentum vectors.
Proto-spiral-galaxies with excess angular momentum would have had diminutive cores, compared to the considerable galactic bulge of mature spiral galaxies. A massive envelope overlying a diminutive core is dynamically unstable, with a diminutive core unable to dampen inhomogeneities in the envelope from amplifying into runaway disk instability.
Runaway disk instability breaks the radial symmetry of the envelope, causing the envelope to clump and form a larger central mass that inertially displaces the former core to a planetary satellite status, in a galactic process designated, ‘flip-flop fragmentation’ (FFF), catastrophically projecting mass inward.
FFF was initially proposed as a catastrophic mechanism for projecting mass inward in prestellar dark cores undergoing freefall collapse, by spinning off cores in the form of gas/ice giant planets. (See section, STARS, PLANETS, MOONS, MINOR PLANETS AND COMETS)
In the Milky Way, the Large and Small Magellanic Clouds are suggested to be former diminutive, proto-Milky-Way cores, spun off in two successive generations of FFF.
In the final instance of Milky Way FFF, the clumping of the envelope ended in the formation of a direct-collapse supermassive black hole, Sagittarius A*; however, since the Large and Small Magellanic Clouds are not known to possess supermassive black holes, apparently smaller/earlier instances of galactic FFF may not necessarily result in direct-collapse black holes.
Baryonic dark matter:
The absence of DM in globular clusters and the absence of a cuspy DM distribution in galactic cores has been called the ‘cuspy halo problem’, which is puzzling to exotic DM theories, but the observed distribution is predictive to baryonic DM ideology if gaseous paleons simply convert to luminous gas and stars in regions of high stellar concentrations or high stellar luminosity.
ΛCDM cosmology assumes exotic DM, but perhaps baryonic DM cosmology need not alter canonical conditions calculated by ΛCDM cosmology at defining epochs, namely at the epoch of nucleosynthesis and the epoch of recombination if baryonic matter only went dark following recombination, with baryon acoustic oscillations (BAO) locked into the CMB prior to the emergence of baryonic DM in Pop III protostars.
Thus presumably temperature, pressure, baryonic matter density, and baryon-to-photon ratio would be canonical (in harmony with ΛCDM cosmology) at the epochs of nucleosynthesis and recombination. And the supposed effect of exotic DM in the plasma realm may be attributable instead to baryonic HGD structure formation.
‘Baryon density’ of the universe is defined to be a constant over time, which is discounted for cosmic expansion by the Hubble constant. Baryon density (Ωbh2) is the ‘baryon density parameter’, Ωb, multiplied by the square of the reduced Hubble constant. When we discuss canonical density conditions at recombination, canonical density refers instead to the instantaneous baryonic matter density at recombination, where canonical conditions, including canonical baryonic matter density, is another way of saying that the two cosmologies are in agreement.
The cosmologies diverge with sequestration of 5/6 of recombination baryons into DM paleons at the epoch of Population III stars, which occurred some time after recombination, but presumably long before the epoch of reionization. Sequestration of 5/6 of the recombination baryons into dark matter suggests six fold less volume expansion of the universe since recombination, compared to ΛCDM cosmology. So if ΛCDM cosmology baryon density of the universe gives a canonical redshift for recombination of z = 1100, the baryonic DM cosmology adjusted redshift suggests a smaller redshift of z ~ 1100/(6^(1/3)) = 605, if 5/6 of the baryons went dark.
At first blush, baryonic DM cosmology gives the wrong value for recombination redshift, that is, unless the missing expansion occurred before recombination. In an alternative baryonic DM cosmology, imagine that recombination occurred closer to 700,000 years after the Big Bang and only appeared to have occurred earlier at 378,000 years after the Big Bang. Then both cosmologies could have a redshift of z = 1100 since 378,000 years after the Big Bang in a 13.8 billion year old universe.
Six times as much baryonic matter, in a baryonic DM cosmology universe, requires six times the volume expansion, which pushes recombination out to around (378,000/(6^(1/3)) = 686,000 ) ~ 700,000 yr after the Big Bang, but at a canonical matter density, pressure, temperature and baryon-to-photon ratio. But since there’s relatively little change in the expansion rate of the universe from the plasma realm to the neutral realm, shifting the date of recombination has little effect on the adjusted expansion rate and the age of the universe, particularly in the context of the missing baryon problem of ΛCDM cosmology. where up to 50% of the baryon density can’t be accounted for.
BAO expansion in the plasma realm from 378,000 to 700,000 yr after the Big Bang, however, would result in an over large BAO scale at actual recombination (700,000 yr after the Big Bang), which might account for the discrepancy between the Hubble constant calculated from the CMB-power spectrum/BAO-scale, of around 67 km/s/Mpc, compared to the Hubble constant calculated from Type Ia supernovae, of around 74 km/s/Mpc. At least the discrepancy is in the right direction. This logic assumes that the Hubble constant derived from Type Ia supernovae is more accurate than the CMB derived Hubble constant, which should be comforting to observational astronomers, since Type Ia supernovae data is more observational and less model based.
Capriotti, Eugene R. and Kendall, Antoony D., 2006, THE ORIGIN AND PHYSICAL PROPERTIES OF THE COMETARY KNOTS IN NGC 7293, The Astrophysical Journal, 642:923–932, 2006 May 10
Gibson, Carl H., 2006, Cold Dark Matter Cosmology Conflicts with Fluid Mechanics and
O’dell, C. R. and Handron, K. D., 1996, Cometary Knots in the Helix Nebula, Astronomical Journal v.111, p.1630
O’Dell, C.R.; McCullough, Peter R.; Meixner, Margaret, 2004, Astronomical Journal, Volume 128, Number 5
Smith, Nathan; Stassun, Keivan G., 2016, The canonical Luminous Blue Variable AG Car and its neighbor Hen 3-519 are much closer than previously assumed, arXiv:1610.06522 [astro-ph.SR]
Tuntsov, Artem V.; Walker, Mark A.; Koopmans, Leon V.E.; Bannister, Keith W.; Stevens, Jamie; Johnston, Simon; Reynolds, Cormac; Bignall, Hayley E., 2015, Dynamic spectral mapping of interstellar plasma lenses, 2016, ApJ, 817, 176
Walker, Mark A., 2013, A snowflake’s chance in heaven, arXiv: 1306.5587v1