© Charles Chandler
|Figure 1. NGC 5128 (Centaurus A) in the x-ray band. The source of the axial jet is in the center of the image, which is the center of the galaxy.
Integral features of the "natural tokamak" (NT
) model include bipolar jets, powerful magnetic fields, and non-blackbody radiation. A variety of star types have such features, such as neutron stars, pulsars, magnetars, quasars, blazars, BL Lac objects, white dwarfs, and the central stars in planetary nebulae. Details concerning the last-mentioned stars (i.e., CSPNe) were described in the Tokamaks
and Egg Nebula
sections. The present section extends the NT
model to incorporate phenomena specific to quasars.
Quasars are actually a broad class of objects with the only thing in common being their "quasi-stellar" properties (hence the name) — they are point sources, and their spectra can vary in as little as a few days, meaning that they are not collections of objects, but they don't emit blackbody radiation like main sequence stars. The spectra that they do
emit are tough to classify. The first quasars were discovered on the basis of their radio frequency emissions,1,2
though less than 10% of all quasars found since then are strong radio sources. They typically emit everything from IR to UV (including x-rays and gamma rays), often punctuated with strong emission lines, but there is no spectral signature common to all quasars.
Due to their high redshifts, quasars are thought to be very far away. If they radiate equally in all directions, their apparent luminosities fall off with the square of the distance, and to be visible at such great distances, their absolute luminosities would have to be greater than giant galaxies. So they were initially believed to be a new type of galaxy, until regular variances in spectra made this untenable. Subsequent studies revealed that quasars are clustered beyond chance within collections of stars that definitely are galaxies, which demoted the quasars to "active galactic nuclei" (AGN). But this didn't make it any easier to understand how a single object could be brighter than the rest of the stars in the galaxy put together. The gravitational loading inside such a large object should cause a runaway thermonuclear explosion, annihilating the star and everything around it. Acknowledging this spawned the hypothesis that gravitational loading can sometimes exceed the limits of nuclear theory, and crush the matter into a black hole. (That doesn't explain how the black hole got that big — how did accretion increase the gravity to the thermonuclear threshold, and then neglect the explosion?) Quasars are then explained as the emissions from matter falling into the black hole, but without explaining how photons propagating through a hypothetical accretion disc (or an accretion sphere for that matter) would result in the observed spectra. (Most problematic are the gamma rays, which are scattered by dust clouds thinner than the Earth's atmosphere.) This also doesn't explain how a gravity source capable of capturing everything in the vicinity — including photons — allows bipolar jets to escape. If the black hole is being fed by an hypothesized accretion disc, the disc should have centrifugal force opposing gravitational capture, while the bipolar jets do not have such a force, and therefore should be more susceptible to gravity. So if there is a Newtonian correlation between accretion discs and bipolar jets, as some of the lay literature suggests, it should be the other way around — the centrifugal force in the disc should pump matter inward along the poles, and outward along the equator.
model doesn't have such problems. The gamma rays are coming from nuclear fusion within the tokamak, which also produces ejecta that get collimated into bipolar jets. (See Figure 2
.) Once collimated, the jets are kept organized by the magnetic pinch effect. The continuous emissions (IR~UV) are synchrotron radiation resulting from the charged particles in the jets spiraling through the elliptical galaxy's magnetic field, which can be several hundred gauss,3
compared to less than a thousandth of a gauss in the arms of a spiral galaxy. So it makes sense that NTs
in elliptical galaxies are much stronger radio sources than in spiral galaxies. It also makes sense that most of the strong gamma ray sources are radio quasars.4
The spectrum of such an object forms a bimodal curve, as in Figure 3
, because the photons are being created by two separate mechanisms (i.e., the tokamak and the bipolar jets).
|Figure 3. Emission spectrum of Markarian 421, a quasar in the Ursa Major constellation, courtesy William C. Keel.
Once accelerated to relativistic speeds and organized by the magnetic pinch effect, how do the jets ever fall apart? The first answer is that even in the extremely thin plasma of interstellar space, there is still a little bit of friction. As the particle stream decelerates, the magnetic pinch relaxes, allowing the jet to expand. When it does, it encounters even more friction, slowing it down even more, and further weakening the pinch. So once the jet starts to fall apart, it doesn't stop until all of its structure is gone. (See Figure 4.)
|Figure 4. Hercules A (3C 348) in radio frequencies, courtesy NASA & ESA.
The bulbous terminations of these bipolar jets are known as Herbig-Haro objects. But not all of the characteristics of HH objects can be fully explained just with fluid dynamics. For example, HH objects frequently undergo flare-ups that are thought to be caused by the collision of the jets with interstellar plasma.5,6
(See Figure 5
.) But the flare-ups propagate at over 1,000 km/s, while the particles in the HH objects are only moving at ~300 km/s, and the speed of sound in the plasma is less than 2 km/s. Thus there are no Newtonian mechanisms capable of transmitting the flare trigger at the observed velocity.
|Figure 5. Flare-ups at ends of bipolar jets.
Newtonian mechanics also cannot explain jets traveling in opposite directions, sometimes for many light-years, and deteriorating into turbulence at so nearly the same distance. If this happened once it would be an odd coincidence, but it happens so frequently as to be considered typical. That isn't odd — it's a rule. Clearly the Herbig-Haro objects are coupled, but fluid dynamics doesn't have a mechanism for this.
The EM radiation from the flare-ups is the result of charge recombination, where photons are released on electron uptake. So how did the charges get separated in the first place? The high thermal energies of particles involved in nuclear fusion inside the NT
provide the velocities for gravitational escape, motivating the jets. This is true of both atomic nuclei and free electrons. But the nuclei have a lot more mass, so when they burrow through stationary matter near the NT
, the electrons tend to get stripped off. This results in collimated bipolar jets of +ions, kept organized by the magnetic pinch effect. (Neutral matter experiences no such effect.) In time, a net positive charge accumulates in the jets, with the lagging net negative charges in pursuit. Once into the interstellar void, the electrons can accelerate. But just as the magnetic pinch effect consolidates like charges, it separates opposite charges. (See Figure 6
.) So the same force that organizes the +ions in the jets will also organize the electron streams trying to catch up with the +ions, and this same force will keep the positive and negative charge streams from recombining.
For charge recombination to occur, either one of two conditions has to be met: either the jets have to slow down, or the electrons have to get in front of the jets, so that they can turn around and meet the +ions head-on. Figure 7
shows this in schematic form. The negative charges near the NT
will rather be a cloud of particles, and a portion of this cloud will get stretched in the direction of the bipolar jets. Shown is just one representative path of travel for the negative charges, but the point here is that the negative charges have to loop back around. They obviously don't "know" to do that — pictured is the stable configuration that evolves. If any clump of electrons randomly finds itself making the 180° turn, it will be drawn vigorously into the +ion stream by the electric force, with the magnetic pressure relieved by the reversal in direction. But as more electrons attempt to follow the same path, magnetic pressure on the inside of the turn will require a broader turn, ultimately getting the negative charge stream to go beyond the +ions before turning back for the head-on collision.
|Figure 7. Possible configuration of charge recombination in bipolar jets, after reversal in direction of electrons to resolve magnetic conflict.
In this context, we can now understand the symmetry of the two Herbig-Haro objects — the trajectory of the free electrons is set by the balance of electric and magnetic forces, which are the same in both directions, and thus the HH objects will occur at the same distance from the central star.
The reversal of direction also figures significantly in solving some of the toughest mysteries concerning quasars. These have to do with the estimated distance, and the absolute luminosity.
One quasar (i.e., ULAS J1120+0641) has a redshift of 7.085. In Big Bang cosmology, this works out to 28.85 billion light-years away, which is problematic for a Universe that is supposed to be only 13.77 billion years old. Even more problematic is that something that far away would have to be brighter than a giant galaxy in order to be visible at that distance. And yet quasars are known to be singular objects, partly by the regular oscillations in luminosity, which couldn't possibly come from a collection of stars. And yet a singular object large enough to shine that brightly would surely have the internal pressure for a runaway thermonuclear explosion, annihilating it and everything around it. That's a few too many impossibilities for us to be sure that we haven't misinterpreted something in the data.
The mistake here is to insist that all redshifts are to be interpreted strictly in terms of Hubble's constant, where redshift equals recessional velocity due to universal expansion, and thus redshift must also equal distance. What if part of the redshift is coming from motion within the quasar itself? Then the redshift is falsely reporting a much greater distance, and quasars are actually much closer. And if they're closer, they're also smaller, which makes them easier to explain with conventional physics.
Closer scrutiny of the data reveals additional reasons to believe that quasars are much nearer. First, quasars are clustered in the sky plane, beyond chance, around galaxies with much lower redshifts (zq
− 2 or more), suggesting that the quasars are members of those galaxies, despite the differences in redshifts.7:5
More tellingly, the differences between the redshifts of quasars in apparent clusters are not random — they are always specific values (i.e., 0.60, 0.91, 1.41, and especially 1.96), known as the Karlsson Periodicity.8
How could quasars, clustered in the sky plane but separated by millions of light years along our line of sight, have redshifts at regular intervals with respect to each other by chance? They don't bear such relationships with quasars outside of their clusters. The only reasonable conclusion is that the quasars in an apparent cluster are related to each other, and to the galaxy.
If quasars are much nearer, their higher redshifts can only be because of motion within the quasars. So what's moving?
|Figure 8. The counter-streaming electrons will accelerate +ions in the same direction. Electron uptake in the yellow region is responsible for the photons we observe.
If we are looking down the axis of a bipolar jet, the +ion stream on the near side is coming toward us, and any photons should be blueshifted by that relative motion. But if the necessary electrons have reversed direction, and are traveling away from us into the +ion stream, it isn't that simple. Figure 8 shows what actually happens when opposing charge streams meet head-on. While the +ions are heavier, the electrons might be traveling at near the speed of light, and they will accelerate some of the +ions by a process known at electron drag. It might take a lot of electrons, moving very rapidly, to accelerate a few +ions in the opposite direction, but this is a well-known phenomenon. And electron uptake, and thus the release of photons, isn't going to occur until both the electrons and +ions have small relative velocities. So the photons are coming from counter-streaming +ions. And since those are moving away from us, the photons will be redshifted.
The redshifts indicate a recessional velocity as high as 18,000 km/s relative to the parent galaxy,7:2
which seems about right for the effects of electron drag, considering that the electrons are moving at close to the speed of light (300,000 km/s). We can also note that the broadening of the spectral lines indicates variances of over 5,000 km/s in the velocity of the plasma9§intro
— this too makes sense, in that there isn't going to be a precise acceleration due to electron drag for every +ion — counter-streaming fluids produce a turbulent mess, and there are going to be variances.
Thus it's plausible that the redshift is artificially high, and the distance to the quasar is more accurately determined by the average redshift of the parent galaxy.
Still, quasars are unusually bright, and tend to outshine their parent galaxies. One quasar (i.e., 3C 273) has an estimated absolute luminosity of 2.00 × 1012
times that of our Sun, which is greater than the average giant galaxy
. This still seems to put them outside of the limits for stellar theory. And yet this too might be misinterpreted. In Figure 9
, we can clearly see the "lighthouse beacons" projecting away from the central star. If we were inside those beams, the star would be much brighter. The beaming mechanism is the greater density of the plasma within the bipolar jets (which have tens of thousands of particles per cm3
, compared to generally less than a thousand per cm3
in H II regions and planetary nebulae10
). Photons traveling through a density gradient are bent in the direction of the greater density. In the case of a magnetically pinched jet, the greater density is toward the axis of the jet. Thus any light that happens to cross the jet at a shallow angle will get refracted into a path that is parallel to the axis. The resulting beacon then misreports the absolute luminosity of the star, since the luminosity isn't falling off by the inverse square law.
When we are looking straight down the axis, and seeing these high redshift spectral lines, we get a different spectrum.9§4
First, we don't see the gamma rays, because they can be scattered by any atom heavier than hydrogen, of which there are plenty in the axial jets. Second, these quasars are not radio loud. That's because synchrotron radiation is directional — it is the strongest parallel to the path of the particles. (See Figure 10
|Figure 10. Beaming effect for a relativistic electron emitting synchrotron radiation. If the magnetic lines of force are perpendicular to the paper, an electron moving left to right will be accelerated to its right, due to the Lorentz force. In the first panel, a non-relativistic electron emits photons that propagate in two equal lobes away from the particle. In the second panel, a relativistic electron emits most of the power into the leading lobe. Image courtesy of Chris Flynn.
If we look at the actual path of charged particles spiraling in an external magnetic field, we see that their motion is not perpendicular to the magnetic field — the helical motion has the particles moving diagonally to the field. (See Figure 11.) So the radiation is strongest when viewed on the diagonal.
Figure 11. Charged particles moving in an external magnetic field fall into a helical motion, due to the Lorentz force. The photons are emitted parallel to the motion of the particles, which in this case means an angle, which then gets swept around the axis as the particles rotate.
Without the gamma and radio frequencies, the spectra of high redshift quasars are somewhat nearer to those of main sequence stars. (See Figure 12
.) But the quasars show strong emission lines, while main sequence stars have absorption bands due to scattering in their cooler outer atmospheres. That's actually what we would expect from quasars, if the light was generated by gravitational compression approaching a black hole — the light should have to pass through cooler matter to get to us. But the absence of absorption, and the presence of strong emission lines, both make sense if the photons are from electron uptake in an axial jet — the point of recombination is deep inside the jet, and traveling toward us from there, the photons pass through hotter matter upstream in the electron flow, meaning matter that is even more ionized, and therefore cannot absorb such frequencies. (The spectra
of the central stars in planetary nebulae are similar.)
|Figure 12. A mean QSO spectrum formed by averaging spectra of over 700 QSOs from the Large Bright Quasar Survey.11 Prominent emission lines are indicated. Data courtesy of P. J. Francis and C. B. Foltz.
Another odd thing for the black hole model is that the relative strength of these spectral lines is roughly the same, indicating similar quantities of each element, regardless of the redshifts of the quasars.9§3
The nature of the oddity is that higher redshifts mean older sources, and there should have been fewer heavy elements in the early Universe to get drawn into black holes, since the heavy elements would have been manufactured in a previous supernova, which the standard model has at the end of the stellar life cycle. This necessitates a flurry of star building within a couple hundred million years of the Big Bang, before
the first supernova to trigger it. In the NT
model, the heavy elements were manufactured inside the tokamak, so no previous supernova is necessary.
Then comes the question of why the redshifts in quasar clusters occur at discrete values (i.e., the Karlsson Periodicity). The speed of the bipolar jets, and of the counter-streaming electrons, should vary continuously with the strength of the driving forces, producing counter-streaming +ions at continuously variable velocities, and thus emitting photons redshifted by arbitrary amounts. Yet there is something that is definitely quantized in this mix: the mass of the +ions, which will definitely affect the rate at which they can be accelerated by electrons. So the most common Karlsson shift of 1.96 might be in plasma dominated by hydrogen, while lesser shifts might come from heavier elements that are harder to accelerate by electron drag.*18380
Next we should address the deviations in the Karlsson Periodicity, which are roughly zk
+/− 0.01, where a greater redshift means greater recessional velocity. This would be due to relative motions of the stars within the galaxies. The speeds were found to be in the range of 900~1200 km/s,7:5
which seems reasonable considering that less powerful stars, such as the Crab Pulsar, are moving at 375 km/s relative to the surrounding nebula.12
So the magnetic thruster of an NT
is easily capable of such speeds, considering that the magnetic field in an active galactic nucleus is several hundred gauss,3
compared to less than a thousandth of a gauss in the arms of a spiral galaxy — operating in a field that is 5 orders of magnitude stronger can easily develop 3~4 times the thrust.
Finally, we should consider the larger environment in which quasars form. While some quasars, especially at the highest redshifts, have not been associated with galaxies, most have, and the galaxies are typically ellipticals. (Quasar-like stars occurring in spiral galaxies are weaker, and are known as Seyferts.) The quasars form near the minor axis, and tend toward the center. In the NT
model, an external magnetic field is important in separating the charges in the imploding filament into oppositely charged strands, and orienting the strands for head-on collisions with oppositely charged strands from the other direction. (See Figure 13
.) There is no reason to be surprised that the far more powerful magnetic field in the center of an elliptical galaxy would be good at forming these most powerful NTs
. But we should acknowledge that it will take extra force for the charged particles to move across the magnetic field. This might require that the filament be particularly robust if it is still to implode with enough momentum to form an NT
. All other factors being the same, charged particles prefer to travel parallel to magnetic lines of force.
With that as the problem, another curious fact about quasars might be the solution: over one third of the host galaxies have small, close companion galaxies, implying that there had been a recent collision.9§2
(Seyfert galaxies show the same relation.9§2
) The significance is that the collider might have been moving perpendicular to the elliptical's magnetic field, and in a collision between two dusty plasmas, the body force that will cause filaments to implode will be parallel to the motion of the particles. (See the section on Filaments
.) Thus the filaments that imploded into quasars might have been the comas trailing behind the collider. The strong statistical correlation between galactic collisions and quasars also tells us that the quasars didn't last long after the collisions (~500 million years9§3
), or both of the colliders wouldn't still be near each other. This isn't terribly surprising — NTs
will burn the brightest with the initial batch of light elements as fuel, but fusing heavier elements into something even heavier requires more energy. So it's just a matter of time before fusion inside the tokamak can no longer support the jets that beam the light our way. The spectral lines are showing 1st
, and 3rd
period elements (H, He, C, N, O, Ne, Mg, and Si), but not much that is heavier. In the 4th
period, fusion starts consuming more energy than it releases, so that might be what shuts down the reactor. Recent research reveals that the extinction can occur rather quickly, with dramatic reductions in luminosity in just 10 years.13
This is not a prediction of the standard model, because it would require the accretion disc to terminate abruptly, while dusty plasmas in the standard model should
have indistinct boundaries. In the NT
model, the quasar isn't feeding on an inflowing accretion disc, but rather, on its own initial angular velocity. This will be attenuated by friction between the counter-streaming charges within the tokamak. While relative velocities are high, the electrical resistance is low, and thus the friction will be slight. But as the particles decelerate, the resistance increases, further encouraging the deceleration. When the relative velocities are no longer strong enough to generate a magnetic pinch capable of nuclear fusion, the tokamak falls apart.
|Figure 14. Number of quasars, showing a peak 12 billion years ago.
We should also note that quasar formation hit a peak about 12 billion years ago. (See Figure 14
. It isn't known whether the fall-off in detection older than that is because there were fewer of them, or because they are harder to find. But the fall-off since
then is reliable.) The significance of this within the NT
model has yet to be determined. Elliptical galaxies typically have little interstellar matter, so it's possible that only when the galaxies were younger, when there were more dusty plasmas available, could the quasars form. It's also possible that there were more galactic mergers back then, if the Universe had a larger number of smaller galaxies interacting more frequently. Another possibility is that this statistic is dictated by redshifts inside the quasars, and doesn't actually indicate age.
Finally, the standard model of quasars has black holes at their centers, with gravitational acceleration being the energy source. The NT
model shows that the more plausible energy source is the implosion of a dusty plasma. If there isn't any need for black holes to power quasars, is there any need for them at all? There are certainly some instances of some large, non-radiating gravity sources. But there is no evidence of such objects possessing any sort of exotic properties, such as event horizons. A large, non-radiating gravity source might just be a large dark star. Or it might be a star with such a thick atmosphere that all of the radiation is scattered.
- Quasars have collimated bipolar jets, and highly focused EM radiation.
- Compensated for focusing, the power output is in the stellar range, not the galactic. So quasars are stars, not galaxies, AGNs, or galactic seeds.
- The radiation is generated by counter-streaming charges in the bipolar jets.
- The high redshift is not from the relative motion of the entire quasar, but rather, from the relative motion of the photon emitters in the bipolar jets, which have been accelerated away from us by electron drag.
- The redshifts are quantized by the mass of the +ions.