Evolution of Quasars
On the basis of the theoretical findings outlined in the preceding pages, the isotopic readjustment activity in the ejected fragment of the exploding galaxy that constitutes the quasar is at a high level in the initial stage immediately following the explosion. The radio emission is correspondingly strong. As time goes on the internal activity gradually subsides, and eventually radio emission ceases, or at least declines to unobservable levels. This radio-quiet stage comes to an end when the constituent stars of the quasar begin to arrive at their age limits in substantial numbers, and the explosions of these stars renew the isotopic adjustment activity. Radio emission then resumes.
The most distant of the quasars that have been identified belong to the class of radio-emitting quasars that follows the radio-quiet stage, Class II, as we will call it. Below a redshift of about 1.00, however, both classes are present, and in order to distinguish between the two it is necessary to identify some properties in which there is a systematic difference between the values applicable to the two classes of objects. Ultimately it should be possible to establish such lines of demarcation from pure theory, but for the present we will have to rely on semi-empirical distinctions. We can expect, for instance, that the evolution of the quasars from the early to the later stages will be accompanied by color changes. Identification of certain specific color characteristics that vary systematically with the quasar age will be sufficient for present purposes. A full explanation of the reason for the observed differences can be left for future investigation.
As noted earlier, the colors of astronomical objects are customarily expressed in terms of color indexes. At this time we will be concerned mainly with the U-B index, which is the difference between the magnitude measured through an ultraviolet filter and that measured through a blue filter. Later we will introduce the B-V index, the color index that we used in dealing with the radiation from the stars, which is the difference between the blue magnitude anti the visual, or photographic, magnitude, obtained through a yellow filter. The empirical data indicate that in the quasars the U-B index is a rough indication of temperature. In main sequence stars the U-B index is positive; that is, more energy is received in the blue range. (It should be remembered that the magnitude scale is inverse.) This index is also positive in ordinary galaxies, which are composed mainly of such stars. Because of the inversion that takes place when the speed of light is exceeded, the theoretical development indicates that in the quasars the color trend should be reversed, and the U-B index should be negative, indicating that more energy is received in the ultraviolet range. All of the U-B values quoted in this chapter are negative, and should be so understood.
The number of quasars on which fairly complete measurements are now available runs into the hundreds, and it will not be feasible to analyze all of these data in a work of a broad general nature. Our examination will therefore have to be limited to a representative sample. The group of quasars studied in Quasars and Pulsars was one for which the redshifts and color data were tabulated by M. and G. Burbidge in their book Quasi-Stellar Objects.250 It includes all of the quasars for which these data were available up to the time of publication, and is therefore free from selection effects, except insofar as it favors the objects that are the most accessible to observation. No significant modifications of the conclusions drawn from the original study have been necessary, and the following discussion will be taken from the earlier publication, with the addition of the results from some subsequent studies, mainly of the same group of objects, those listed in the Burbidge table 3.1.
The color indexes are determined primarily by the internal activity (the temperatures, together with the isotopic adjustments and their consequences) within the quasars. The pattern of change during the evolution of the quasars should therefore be capable of being evaluated on a purely theoretical basis. Such a project is beyond the scope of this work, but the general nature of the changes that take place in the indexes, as empirically determined, shows a definite qualitative correlation with the changes that theoretically occur in the generation and dissipation of energy. We can therefore set up some defining criteria for these quasar classes on a semi-empirical basis.
In the original study reported in Quasars and Pulsars the division was established at U-B = 0.60 and an absolute ratio flux (R.F.) of 6.0 measured at 178 MHz: All quasars with U-B values less than 0.60 were placed in Class I. Those having higher U-B, but R.F. below 6.0 were found to be continuous with the low U-B quasars in their properties, and were also assigned to Class I. The high R.F.-high U-B quasars form a discontinuous group with quite different properties, and were identified as members of Class II.
Figure 26 shows the relation between U-B and R.F for those of the Class I quasars listed in the Burbidge Table 3.1 for which the necessary information is available. This diagram is essentially equivalent to the astronomers’ “two color diagram,” except that the scales have been inverted because we are here dealing with phenomena of am inverse region, the region of intermediate speeds. We will use both colors later, with and without the radio flux. It would be convenient to define the quasar classes on the basis of color alone, and some progress in this direction will be made when the B-V index is
introduced later in this chapter, but color criteria that are capable of defining these classes in a manner that is free from ambiguity have not yet been developed.
When a quasar is first ejected from the galaxy of origin, its constituents are in a state of violent activity, and its radio flux is abnormally high. Only one of the quasars included in the group under consideration is still in this very early stage. This is 3C 196, which has U-B = 0.43 and absolute R.F. = 4 × 0.3. Its redshift is 0.871, of which 0.054 is the normal recession component. In this work the symbol z is used to represent the normal recession redshift only. The explosion-generated component, usually 3.5 z½ but subject to modification of the redshift factor 3.5, will hereafter be designated as q, and the total quasar redshift will be represented by the symbol Z. We then have the relation Z = z + q. We will also want to recognize that the redshift component q represents an equivalent distance (that is, a distance in the spatial equivalent of time), and we will call this the quasar distance. The quasar distance of 3C 196 is 0.817, which makes it one of the most distant Class I objects in the Burbidge table.
After the initial spurt of activity in a quasar dies down to some extent, it can be found in the zone designated “early” in the upper left of Figure 26. As it ages, and its activity drops still further, it moves to the right (toward lower R.F.) and downward (toward higher U-B). Ultimately it passes the zero radio flux line and enters the radio quiet stage.
The tabulated data show that at the time they were compiled no Class I quasars had been detected at quasar distances greater than 0.900, and no objects of this class that are old enough to have U-B indexes above 0.60 had been found beyond a quasar distance of approximately 0.700. The significance of these figures lies in the fact that the high R.F. quasars with U-B indexes above 0.60 (Class II) can be detected beyond a quasar distance of 0.700. Indeed, we can follow them all the way out to the ultimate limit at 2.00. It is clear, then, that these more distant objects are not in the same condition in which they were when they were originally ejected. In order to move into the range in which they are now observed these distant Class II quasars must have undergone some process that released a substantial amount of additional radiant energy at radio wavelengths.
We have already deduced that such a process exists. Because of the long period of time during which a quasar is traveling outward before it arrives at the point where it converts to the cosmic status, some of its constituent stars reach the age that corresponds to the destructive limit. Secondary Type II explosions then occur. Obviously, this is just the kind of a process that is required in order to explain the emergence of a second class of radio-emitting quasars at distances beyond the observational limit of Class I objects. It should be noted that a secondary series of explosions is a natural sequel to the original explosion of the giant galaxy. That original explosion was initiated as soon as enough of the oldest stars in the galaxy reached their age limits. The stars in the ejected fragment, the quasar, were younger, but many of them were also well advanced in age, and after another long period of time some of these necessarily arrived at the age limit.
The original stellar explosions occurred outside the portion of the galaxy that was ejected as a quasar; that is, they took place in the interior of the giant galaxy of which the quasar is a fragment. Thus the radio emission from a Class I quasar is mainly a result of the extremely violent ejection. On the other hand, the secondary explosions occur in the body of the quasar itself, and the emission from the Class II quasars comes directly from the exploding stars. This difference in origin is reflected in the relation between the U-B index and the radio flux, enabling us to utilize this relation as a means of distinguishing between the two classes. Figure 27 is a plot of U-B vs. R.F. for the Class II quasars in the Burbidge table. As can be seen, the points representing these objects tall entirely outside the section of the diagram occupied by the quasars of Class I. There is no indication in this diagram that the Class II quasars follow any kind of an evolutionary pattern, but we will give this question some consideration later.
The quasar 3C 273 is of particular interest. This is definitely a Class II quasar, according to the criteria that have been defined, but its distance is far
out of line with that of all other known objects of its class. No other Class II quasar in the group we are now examining has a quasar distance less than 0.315, whereas the quasar distance of 3C 273 is only 0.156. Ordinarily we can consider that when we measure the redshift of an object we are also determining its maximum possible age, as this age cannot be greater than the time required to move out to its present position. On this basis, we would interpret the low redshift of 3C 273 as an indication that it is an unusually young Class II quasar. This could be true. It was pointed out in the earlier discussion that the secondary explosions may occur relatively soon after the original ejection, inasmuch as some of the stars in the galactic fragment that is ejected as a quasar may already be near the age limit at the time of the explosion. Very young Class II quasars are therefore definitely possible
But 3C 273 is not necessarily young. It may be very much older than the 0.156 quasar distance would indicate, as the general relation between redshift and age does not hold good at very short distances where the magnitude of the possible random motion is comparable to that of the recession. Two galaxies that are separated by a distance in the neighborhood of their mutual gravitational limit can maintain this separation almost indefinitely, and the width of the zone in which the relative motion can be little or none at all is increased considerably if there is random motion with an inward component. Hence 3C 273 may have spent a long time near its present position relative to our Milky Way galaxy, and may be just as old as the quasars at distances around 0.300.
The observational information currently available is not adequate to enable making a definite decision between these alternatives, but where we have a choice between attributing an unusual situation to a chance coincidence that has resulted in an object of a relatively rare type being located very close to us, or attributing it to a unique characteristic which we know that the object in question does possess -its proximity -the latter is clearly entitled to the preference pending the accumulation of further evidence. We therefore conclude tentatively that 3C 273 is at least as old as the Class II quasars in the vicinity of quasar distance 0.300.
The position of 3C 273 in Figure 27 is indicated by a triangle. As can be seen from the diagram, this quasar is among the weaker radio emitters in its class (although we receive a large radio flux from it because it is so close) but, so far as its properties are concerned, it is not abnormal, or even a borderline case. Its proximity therefore provides a unique opportunity to observe at relatively close range a member of a class of objects that can otherwise be found only at great distances.
Further experience in application of the U-B criterion to distinguishing the quasar classes has indicated that it is somewhat ambiguous in the region of high U-B values and low radio emission. Introducing the B-V index has therefore made an adjustment of the selection criteria. In this region of high (more negative) U-B values, the location where the original criteria proved to be deficient, there are some quasars with low radio emission that have absorption redshifts. As brought out in Chapter 23, this is an indication of advanced age, which places them in Class II. These objects have B-V indexes in the upper portion of the full range of values, whereas the indexes of the relatively low redshift quasars in this region, which can be expected to be Class I objects, fall in the lower portion of this range. We may tentatively establish a dividing line at B-V = +0.15, and instead of assigning all quasars with low radio emission and high U-B indexes to Class I, we will put those members of this group that have B-V indexes above 0.15 in Class II. Until such time as we are able to base the selection criteria on a theoretical rather than an empirical foundation we can hardly expect precision, but this change to a two-color basis undoubtedly brings us closer to the correct line of demarcation. The revised color index pattern for quasars at distances below 1.00 is shown in Table X. Included in this revision is a change in the U-B classification boundary from 0.60 to 0.59.
The identification of the evolutionary status of the quasars by color and radio flux (or distance) enables utilizing the data with respect to the other observable features of the quasars to verify the theoretical conclusions as to the differences
|I early||Below 0.59||Below 6.0|
|I late||Above 0.59||Below 0.15||Below 6.0|
|II early||Above 0.59||Above 0.15||Below 6.0|
|II late||Above 0.59||Above 6.0|
between the classes, and between the earlier and later members of each class, something that we could not do if these features entered into the criteria by which the classes are identified. For instance, we have deduced from theoretical premises that the absorption, which gives rise to the absorption redshift lines in the quasar spectra, takes place in clouds of material accelerated to high inverse speeds by internal supernova explosions in these objects. No absorption occurs, therefore, until these explosions occur on a sufficiently large scale. As noted earlier, this point is not reached until the quasar is somewhere in the radio quiet stage, while it is evident from the nature of the requirements for the production of multiple absorption redshift systems that multiplicity will not appear until a still higher level of activity is reached. On the basis of this evolutionary pattern, we can deduce the following rules regarding the occurrence of absorption redshifts:
- Class I quasars have no absorption redshifts.
- Absorption redshifts approximating the emission values are possible throughout most of the radio-quiet region, and in the Class II radio-emitting quasars.
- Absorption redshifts differing from the emission values by more than the amount that can be attributed to random motion are possible only in Class II quasars and relatively old radio-quiet quasars.
A check of 29 quasars with absorption redshifts listed in a 1972 compilation by Burbidge and O’Dell251 shows that all of these objects are in compliance with the foregoing rules when the assignment to classifications is made on the basis that has been specified. Here, then, we have a significant confirmation of the theoretical description of the conditions under which the absorption redshifts occur.
It was noted earlier that there would be a further advantage in being able to distinguish the two classes of radio-emitting quasars by color alone without having to consider the magnitude of the radio emission. As indicated in Figure 28, which is a combination of Figure 26 and 27, with the B-V index substituted for the radio flux, this is almost accomplished by the resulting two-color diagram. There is some uncertainty along the dividing line at the 0.15 B-V index, and there is one deviant object, 3C 280.1, which has a B-V index of 0.13, although its redshift far exceeds the Class I limit. Otherwise, the two classes of quasars are located in separate portions of the diagram, as in Figure 26 and 27. The deviation of 3C 280.1 from the normal range of B-V indexes is probably due to the same cause as the deviation of this quasar from the normal radio pattern, as shown in Table VII, Chapter 22.
Thus far we have been looking at the color indexes and radio flux as means of differentiating between the various classes of quasars. Now we will want to examine the significance of the changes that take place in these quantities during the evolution of the quasars. The magnitudes of all of the properties that we are now considering undergo evolutionary changes. Thus any one of them can serve as an indicator of quasar age. Obviously, however, the properties that change most uniformly with time are the best indicators, and on this basis we may consider the radio flux in Figure 26 and 27 as indicating the quasar age. These diagrams thus show how the quasar temperature (U-B) varies with age (R.F.). We now find that the B-V index follows approximately the same trend as the radio flux, which means that this index is also an indicator of age, and can be substituted for the radio flux in the diagrams.
The U-B indexes of the earliest Class I quasars fall in the range from about -0.40 to -0.59. As these quasars age, the index moves almost horizontally to the vicinity of B-V = +0.15, and then turns sharply downward on the diagram (toward more negative values) as the radio-quiet zone is approached. The B-V index of the earliest Class I quasar in the sample under examination is 0.60. This index decreases as the quasar ages, reaching positive or negative values near zero at the radio-quiet boundary. The U-B indexes of the Class II quasars range from -0.59 to about -1.00, with no apparent systematic variation. The corresponding B-V indexes for most of the Class II quasars with relatively low redshifts (below 0.750) are in the neighborhood of +0.20. Beyond 0.750 the index increases, and the maximum values around 0.60 or 0 70 are reached near the 1.00 distance. This peak is followed by a decrease to a level at which most values are comparable to those of the early members of this class.
While the actual mathematical relations between the internal activity of the quasars and their color indexes have not yet been examined in the light of the Reciprocal System of theory, the evolutionary pattern followed by the values of these indexes, as described in the preceding paragraph, shows a definite qualitative correlation with the changes that theoretically take place in the generation and dissipation of energy. In Class I the initial energy is high, but it gradually subsides, as no continuing source of large amounts of energy is available to these objects. Both color indexes respond to this change by moving toward more negative values as the quasars age. In Class II the initial activity develops slowly, as it originates from many small events rather than from one big event, and the Class II quasars do not reach the high temperatures that are characteristic of the early Class I objects.
The lowest (least negative) U-B values in Class II are in the neighborhood of the dividing line at -0.59, and the full range extends to about -1.00. The five radio-quiet quasars in the Burbidge tables for which color indexes are given have U-B indexes in the range from -0.78 to -0.90. It follows that only those quasars with U-B indexes between about -0.75 and the -0.59 limit can be regarded as having a temperature increment due to the secondary explosions, and even in this group, which includes about 40 percent of the total number of Class II Quasars, the increment is not large There is no systematic change with age in the U-B indexes of these Class II objects. This is understandable on the basis of the conclusion that this index is related to the temperature, as the temperature variations in Class II are due to events that can take place at any time during the Class II stage of quasar existence.
The pattern of values of the B-V index that was previously described indicates that the processes, which determine the magnitude of this index, are increasing in strength throughout the Class II stage. The specific nature of these processes has not yet been established but obviously they are aspects of the motion of the quasar constituents, and for the present we can use the very general term “internal activity” in referring to them. As the quasar distance increases, the average age of the observable quasars rises, inasmuch as the age range is continually being extended. This increase in age is accompanied by a corresponding increase in internal activity, and, below a quasar distance of 1.00, by an increase in the B-V index. As already mentioned, this index decreases beyond 1.00 distance, probably because of a decrease in the intensity of the internal activity due to the dimensional distribution of the various properties of the quasars that occurs in this distance range.
Inasmuch as the concentration of energetic material in the interior of the giant spheroidal galaxy from which a quasar was ejected was built up gradually over a long period of time, the isotopic adjustments taking place in this material at the time of the ejection are mainly of the long-lived types. Thus the decrease in radio emission and “internal activity” in the early quasar stage should be quite gradual. The temperature, on the other hand, is raised to a very high level by the explosion, and can be expected to take a very sharp initial drop. We would normally expect, therefore, that the early Class I stage would begin with an exponential decrease in the U-B index (temperature) as a function of the B-V index (age). But this is not at all what Figure 28 indicates. There is little, if any, decrease in the U-B index in the early Class I stage. Let us see, then, if we can account for the observed situation.
One obvious possibility is that the rapid decrease in the temperature precedes the earliest quasar stage. On this basis, the temperature of the newly ejected galactic fragment drops rapidly to a certain level, which we can identify as that of the earliest Class I quasars (U-B = -0.40 + 0.10), remains at this level to about B-V = +0.15, and then resumes a rapid drop to a minimum level near 1.00. On first consideration, this may appear to be another of the combinations of ten percent fact and ninety percent speculation that are so common in the relatively uncharted areas of physics and astronomy. However, there actually is in existence a class of objects, not currently identified as quasars, that occupies the position in this U-B vs. B-V diagram in which the theoretical very early group of quasars would fall if the foregoing explanation of the nature of the early evolutionary pattern is correct.
Like the quasars, these objects are abnormally small, very powerful extragalactic bodies. Their existence was first recognized when the radiation from the “variable star,” BL Lacertae, was found to have some very peculiar properties. Several dozen similar objects have since been located. Because their properties are in some respects unique, they have been placed in a new astronomical category. However, no consensus has been reached on a name for these objects. As matters now stand, we have a choice between BL Lac objects, lacertids, and lacertae. The latter term will be used in the discussion that follows.
Most of the differences between the lacertae and the quasars are merely matters of degree, as would be expected if the lacertae are very young quasars. For instance, the evidence of association with giant galaxies is much stronger than in the case of the quasars. Joseph S. Miller describes the results of a recent (1981) investigation in which both lacertae and quasars were examined as follows:
We conclude that the data are consistent with all BL Lac objects being located in luminous giant elliptical galaxies… No galaxy components were definitely detected for any of the QSOs in this study.252
These observations are consistent with the status of the lacertae as pre-quasar explosion products. The observed galaxies are the giants—spheroidal, in the terminology of this work—from which these objects were ejected. The parent galaxies are more likely to be observed while the explosion products are still in the lacertae stage immediately following ejection because these products have not yet had time to travel very far. By the time the quasar stage is reached the ejected fragment has moved farther away from the galaxy of origin, and the association between the two is not necessarily evident.
All known lacertae are radio sources, whereas many, perhaps most, quasars are radio quiet. Here again, the difference is accounted for if we accept the conclusion that the lacertae are the initial products of the galactic explosions; that is, they are in the violent post-ejection stage. This conclusion is supported by the observation that “The BL Lac type objects appear to be very closely related to violently variable QSO’s like 3C 279 and 3C 345 (two quasars of Early Class I).”253 The reason for the lack of radio-quiet lacertae is then evident. The violent internal activity that produces the radiation at radio frequencies continues throughout both the lacertae and Early Class I stages.
It has been found that the bright lacertae are not associated with extended radio sources,254 whereas most quasars of the early classes do show such an association. Here, again, extreme youth is the explanation. The extended sources have simply not had time to develop.
The radiation from the lacertae includes optical, radio, and infrared components, all of which are to be expected from young explosion products moving at upper range speeds. No x-ray radiation has been detected. This, too, is consistent with the theoretical evolutionary status of the lacertae. There are no x-rays in very young explosion products, as we saw earlier in the case of the supernovae. Objects that lose energy after having been accelerated to upper range speed levels emit X-rays. By the time the ejected fragment reaches the quasar stage, some loss of energy has taken place, and production of x-rays has begun.
A clear picture of the relation between lacertae and quasars is provided by the respective colors. To illustrate this point, the colors of a representative group of lacertae254 have been added to Figure 28, and the enlarged diagram is shown in Figure 29. Quite clearly, the positions of the lacertae in this two-color diagram are fully consistent with the theoretical conclusion that these objects are the initial products of the galactic explosions, and precede the early Class I quasars in the evolutionary development of the ejecta from the explosions. Except for a few objects that have penetrated into the Class II region of the diagram, the evolutionary path of the lacertae joins that of the Class I quasars in a smooth transition, and the combined path follows the pattern that, as explained earlier, we would expect the galactic explosion products to follow in their early stages, on the basis of the theory that we have developed.
One more of the distinctive characteristics of the lacertae remains to be examined.
The most intriguing difference between quasars and lacertae is that the quasars have strong emission lines in their spectra that the lacertae lack. The reason for this is not yet understood.255 (Disney and Veron)
This, too, is readily explained on the basis of the theoretical description of the immediate post-ejection conditions. The principle that plays the most important role in this situation has been encountered repeatedly in connection with other phenomena discussed in the preceding pages, but it is one of those items that is so foreign to existing physical thought that it may be a source of conceptual difficulty for many readers. A more detailed discussion is therefore appropriate at this point, where the relevant observational evidence is more extensive than in the applications considered earlier.
For reasons already specified, the radioactivity and the accompanying emission of radiation at radio frequencies decline slowly throughout the Class I quasar stages. This decline is illustrated in Figure 30 Here the absolute radio emissions are plotted against the U-B color indexes (indicative of the temperature) in steps 0.02 of the index. This procedure results in some values that are averages of two or three individual emissions, thereby smoothing the resulting curve to some extent. The circled points indicate the average values. Those not so identified are single values. As might be expected from the nature of the radio emission process, there are a few widely divergent values, but the general trend is clearly represented by a line such as that in the diagram, which conforms to the theoretical expectation.
The optical situation is more complicated because the stellar component speeds that are produced by acquisition of a part of the explosion energy are much lower than those of the gas and dust particles that supplied the original explosion energy. These stellar components therefore return to the speed range below unity during the evolution of the Class I quasars. The effect on the optical emission is shown in Figure 31, which is similar to Figure 30, with the absolute optical luminosities substituted for the radio emissions. (The methods of calculating the absolute values of both the optical and the radio emissions will be explained in Chapter 25.) Here we see that the luminosity remains nearly constant in the initial range, up to about U-B = - 0.50. It then begins a rapid rise to a point in the neighborhood of -0.59. At this point the emission drops by one half. During the late Class I stage, which follows, there is a moderately fast decrease to a level below -0.05 at the point of entry into the
Since the stellar component speeds that are primarily responsible for the magnitude of the optical luminosity are subject to the same conditions that apply to the radio emission; that is, a gradual decay of the effects of the explosive ejection. the peak in the luminosity curve is somewhat surprising on first consideration. But, in fact’ two different processes are involved. The isotopic adjustments that produce the radio emissions decrease gradually in intensity as more and more of them are completed. The optical emission is a function of the temperature; that is, of the speeds of the component particles. In the low speed range with which we are all familiar, the rate of emission of radiation increases with the component speeds (the temperature). It might seem that a still further increase in the speed would lead to a still greater rate of emission. But in the universe of motion directions are reversed at the unit level. Consequently, the same factors that cause the radiation to increase as the component speeds approach unity from lower levels also operate to increase the radiation as unit speed is approached from the higher levels. It follows that the radiation is at a maximum at the unit level, and decreases in both directions.
Applying this principle to the Class I quasars, we see that in the U-B range as far as -0.45, the component speeds are nearly constant as they slowly
approach their maximum, and begin to decrease. Then the continued radiation losses with no comparable replacements accelerate the rate of decrease, reaching a maximum at the unit speed level. During this interval, while the speeds are still above unity, the decrease in speeds results in an increase in the rate of emission, reaching a peak at unit speed. As the diagram indicates, this peak coincides with the dividing line between classes I and 11 at U-B = -0.59. Beyond this point the speed drops into the range below unity, the range in which a decrease in temperature results in a decrease in the radiation. Like gravitation, the radiation process is operative in both of the active dimensions of the intermediate region. Half of the radiation is therefore eliminated at the unit speed level.
The lack of emission lines in the spectra of the lacertae is another result of this radiation pattern. The immediate post-explosion speeds of the gaseous component of the explosion products are very high, probably close to the two unit level. As brought out in Chapter 15, this is the zero for motion in time, and the physical condition of an aggregate at this temperature is similar to that of an aggregate at a temperature near the zero of motion in space. The explanation of the lack of emission lines, then, is that the temperatures of the gases in the lacertae are too high to produce a line spectrum. At these extremely high temperatures (low inverse temperatures) the aggregate is in a condition in time that is analogous to a solid structure in space, and like the latter it radiates with a continuous spectrum. This is another example of the same phenomenon that we noted in Chapter 16 in connection with the continuum emission from the Crab Nebula. By the time the quasar stage is reached, the temperature has dropped enough to give the aggregate the normal characteristics of a gas, including a line spectrum.
It was evident from the time of the earliest studies of the different classes of quasars, reported in Quasars and Pulsars, that the -0.59 value of the U-B index marks some kind of a physical division, and this was one of the criteria on which the classification of the quasars in that publication was set up. It can now be seen that the -0.59 U-B level corresponds to unit temperature. The fact that the evolutionary path of the Class I quasars (including the lacertae) contains a horizontal section, rather than decreasing somewhat uniformly from the initial to the final state, as might be expected where there is no source of replacement for the energy that is being lost by radiation, is explained by the transition from two-dimensional to one-dimensional motion. The energy of the second dimension of motion in the intermediate speed range is analogous to the heats of fusion and vaporization. When the change to one-dimensional motion takes place, the energy of motion in the other dimension becomes available to maintain the temperature, and the U-B index, at a constant level for a time before the decreasing trend is resumed.
Incorporation of the lacertae into the path of development now completes the evolutionary picture of the Class I explosion products from the time they are ejected from the galaxy of origin to their entry into the radio-quiet stage. Some of these objects may disappear during that stage, for reasons that will be explained in the next chapter. The remainder eventually undergo secondary explosions and attain the Class II status. There is no systematic relation between the temperature and age in Class II, because both the time at which the secondary explosions occur and their magnitude are subject to major variations. Each individual Class II quasar does, however, follow a course that eventually brings it to the point where it crosses the sector boundary and disappears.
There are many pitfalls in the way of anyone who attempts to follow a long chain of reasoning from broad general principles to specific details, and since this is an initial effort at applying the Reciprocal System of theory to the internal structural features of the quasars, it must be conceded that modification of some of the conclusions that have here been reached is likely to be necessary as observational knowledge continues to accumulate. and further advances in theoretical understanding are made in related areas. However, the general picture of the quasar structure and evolution derived from theory corresponds so closely with the information now at hand that there seems little reason to doubt its validity, particularly since that picture was developed easily and naturally from the same premises on which the earlier conclusions regarding the origin and nature of the quasars were based.
It is especially significant that nothing new is required to explain either the existence or the properties of the quasars (including the lacertae). Of course, nothing new can be put into a purely deductive theory of this kind. Introduction of additional hypotheses or ad hoc assumptions of the kind normally employed in the adjustment of theories to fit new observations is excluded by the basic design of the theoretical system, which calls for deriving all conclusions from a single set of premises, and from these only. Some new principles and hitherto unknown phenomena are certain to be revealed by any new theoretical development of this magnitude, and many such discoveries have, in fact, been made in the course of the theoretical studies thus far undertaken. Such items as those utilized in the foregoing applications of the theory to the various aspects of the quasar situation -the status of all physical phenomena as more or less complex relations between space and time, the inversion of these relations at unit levels, the role of time as equivalent space, and the asymmetric transmission of physical effects across unit boundaries - are all new to science. But these are not peculiar to the quasars; they are general principles, immediate and direct consequences of the basic postulates, the kind of features that distinguish the universe of motion from the conventional universe of matter, and they were discovered and employed in a variety of applications decades before the quasar study was undertaken. All of the novel principles deduced from theory and utilized in this work were explicitly stated in the initial presentation of the Reciprocal System of theory in the first edition of this work, published in 1959, years before the quasars were discovered.
Furthermore, many of the consequences of these general principles, in the form of physical phenomena and relations, that are now seen to play important parts in explaining the origin and evolution of the quasars were likewise pointed out in detail in that 1959 publication, four years before Maarten Schmidt measured the redshift that ushered in the era of the quasar “mystery.” The status of stellar aggregates as structures in positional equilibrium, which permits the building up of internal pressures in the galaxies, and the ejection of fragments, the existence of two distinct divisions of the explosion products, ejected in opposite directions, one moving at normal speed and the other moving at a speed in excess of that of light; the reduction in the apparent spatial size of aggregates whose components move at upper range speeds; the generation of large amounts of radiation at radio wavelengths from the explosion products; and the eventual disappearance of the ultra high speed material; were all derived from theory and discussed in the published work, not only long before the discovery of the quasars but years before any definite evidence of the galactic explosions that produce the quasars was found.