1. INTRODUCTION

If the Standard Model of Cosmology (currently the Lambda-Cold Dark Matter concordance model) is to survive intact and remain the preferred explanation for the origin and behaviour of the Universe, it should adapt to and accommodate observational challenges. The information presented here forms a list of apparently anomalous observational results in cosmological redshift studies. It is a broad review using selected examples, and aspires to do no more than provide some pointers to those who may be inclined to investigate further. The literature is replete with rebuttals and counter-explanations for the first-pass interpretations given by the investigators quoted here, followed by rebuttals-of-rebuttals in an ongoing and inconclusive debate between fine minds. This is both to be expected and welcomed as good science. In the interests of brevity, however, this article does not attempt to transcribe the extensive point-and-counterpoint of the debate such as it has already manifested itself, but rather to compile an economical summary of observational results together with original analyses by the authors of those discoveries. Thus, for example, the obvious alignment of Quasars (Quasi-stellar objects - QSOs) about active galactic nuclei (AGN) is no longer in general dispute; the explanations of such phenomena most certainly are.

The physical properties of quasars themselves are in contention. There are two opposing models. The orthodox view, derived from theory, holds that QSOs are in effect halos around nuclear Black Holes in galaxies that are highly turbulent and disrupted (AGN), for example Seyfert galaxies. This model seeks to explain the immense luminosity of these objects by attributing their energy to the process of Black Hole accretion. The opposing view, derived from observation, is that QSOs are proto-galaxies ejected from progenitor active galaxies with intrinsically high redshift, meaning that they are nearby with luminosity that is normal.

It has been suggested that the alignment of high redshift quasars with low redshift galaxies is a residual arrangement emanating from earlier times in history. It is entirely irrelevant to the terms of this summary how the association originated. If such an association is observed and verified, then it is anomalous in that the Hubble law is compromised. In other words, objects at the same physical distance from us (high redshift quasars and low redshift nuclear galaxies) give different distance signatures, and we are left with the dilemma of which of the varying redshifts to take as indicating recessional velocity and remoteness. In other words, objects at the same physical distance from us (high redshift quasars and low redshift nuclear galaxies) give different distance signatures, and there is in some unspecified cases an additional component to cosmological redshift besides velocity which must be considered.

The first question that needs to be answered in a review of anomalous redshift data is, "What is the statistical significance of the samples being cited? " Put another way; are anomalous redshift associations just extremely rare events that can be written off to chance alignments and optical illusion? For decades this was the criticism levelled particularly at the observational work of Halton Arp, so it is appropriate to let him answer it:

"Fulton & Arp have analyzed the positions, redshifts, and magnitudes of ~118, 000 galaxies and ~25,000 quasars in the 2dF deep field. The examination of individual samples revealed concentrations of high z galaxies and quasars near galaxies. A natural extension of the analysis was to determine the average densities of objects over the survey area as a whole" --Fulton and Arp (2008a).

Redshift is an extremely important quantity in astrophysics, and supports a large body of theory. In cosmology, it gives us the radial calibration along line-of-sight that determines almost exclusively the depth in 3-D representation of non-local structure. In 1929, Edwin Hubble revealed that for the fairly local galaxies in his field of view, the fainter they are, the higher the redshift appeared to be. This led to the conclusion that there was a correlation between redshift and distance, given by the inverse-square law for the dissipation of light energy with distance travelled.

However, from the outset, these redshift data patterns were indistinct and tenuous. Hubble’s original redshift data were described by Weinberg (1977) as leaving him "perplexed how he (Hubble) could reach such a conclusion—galactic velocities seem almost uncorrelated with their distance, with only a mild tendency for velocity to increase with distance."

Hubble himself remained unconvinced that the Doppler Effect correctly explained his observations. Hoyle, Burbidge, and Narlikar (2000) recount Hubble’s uncertainty: "In his last discussion of the observations, Hubble in the George Darwin lecture at the Royal Astronomical Society in 1953, a few months before he died, gave the first results obtained using the 200-inch telescope…Sandage has pointed out that using the ‘no recession factor’ (meaning no correction for the number effect), Hubble was still doubtful if the expansion was real."

A crucial backdrop to this discussion is that the Standard Model of Cosmology describes a partially static (that is, both expanding and non-expanding) Universe. Arbitrarily-defined "local" space is excluded from expansion. In Hoyle, Burbidge, and Narlikar (2000, pp 32—33), we learn that, "In the case of the redshifts it had been accepted that they must be corrected for solar motion with respect to the centroid of the Local Group, since it had been realised since 1936 that the systematic redshift does not operate within the Local Group."

In the classic text The Principles of Physical Cosmology Peebles, (1993, p71), explains the phased nature of expansion: "The expansion of the universe means that the proper physical distance between a well-separated pair of galaxies is increasing with time, that is, the galaxies are receding from each other. A gravitationally bound system such as the Local Group is not expanding … the homogeneous expansion law refers to galaxies far enough apart for these local irregularities to be ignored."

Due to uncertainties brought about by observational contradiction of the model’s requirement that the large-scale Universe be homogeneous and isotropic (the Cosmological Principle), and also whether super galactic clusters can be considered gravitationally bound, no definite theoretical radius can be arrived at to delimit where non-expanding space ends and expanding space begins. The general consensus is that at the very least, expansion of space commences only at distances > ≈ 100Mpc (326,000,000 light years), measured radially from Earth. For the sake of the ensuing discussion we will accept the consensus view. However, the implications of this are onerous for redshift astrophysics. It is consequently impossible to test redshift-expansion against parallax distance measures, the most reliable method for quantifying celestial remoteness but currently limited to ≈ 300 light years from point of observation due to constraints on baseline scale. No verifiable, independent test of cosmological distances on the Mpc scale has yet been devised.

Historically, galaxy count catalogues compiled by Abell (1958), Zwicky et al (1961—1968), and Arp (1966) made no attempt to reconcile redshift values with other properties in space. However, the data were invaluable to later analysts constructing 3-D interpretations. The Sloan Digital Sky Survey (SDSS) and the Centre for Astrophysics (CfA) survey, as two examples of modern works, have given us 3 dimensional interpretations of pie slices of the universe that rest, or fall, with redshift distance. All these mentioned surveys produced peculiar patterns when arranged spatially according to redshift, and even more obvious anomalies where resolution permitted detection of material connections between bright objects. M.B. Bell (Bell, 2006) sums it up, "Because the belief that the redshift of quasars is cosmological has become so entrenched, and the consequences now of it being wrong are so enormous, astronomers are very reluctant to consider other possibilities. However, there is increasing evidence that some galaxies may form around compact, seed objects ejected with a large intrinsic redshift component from the nuclei of mature active galaxies."

2. PHENOMENOLOGY

Anomalous redshifts, defined as quantities significantly at variance with the Hubble Law, are present in various ways. The Standard Model of Cosmology requires a direct, systematic relationship between the redshifts and remoteness of astrophysical objects in non-local, expanding space; conversely, it requires equally that such a relationship should not present itself in local, non-expanding space. Whether the arrangement in an observed system is or is not anomalous is therefore indicated by "properties of nearness, alignment, disturbances, connections" (Arp, Burbidge, & Burbidge, 2004). Thus, it may be assumed that there is something anomalous about measured redshift if:

2.1. There is a prevalence of high redshift objects near the nucleus of nearby galaxies, or high redshift galaxy-like systems are apparently associated with low redshift clusters;

2.2. Physical connections are seen between objects with significantly varying redshifts;

2.3. Apparent proximity of high redshift objects is given by non-redshift distance indicators;

2.4. Radial alignment suggests ejection and common origin of objects with excessively varying redshifts;

2.5. Absorption lines (or lack thereof) of higher redshift objects places them in the foreground of lower redshift background systems;

2.6. Morphological associations, for example asymmetries in rotation curves or overall shapes, in contradiction of redshift distance. This evidence, although documented in the literature, is not included in this review;

2.7. The redshift is systematically quantised in discrete values along preferred peaks (the Karlsson Effect);

2.8. Radial or transverse expansion rates of neighbouring objects exceed the speed of light if assumed to be at redshift-given remoteness;

2.9. The Hubble law is found in the redshift-luminosity relation of objects in local, non-expanding space;

2.10. Significant proper motion is evident in high-redshift objects.

3. OVERVIEW

3.1 Galaxies. Our descriptive knowledge of galaxies increased exponentially from the time of Hubble’s first foray into extra-galactic astronomy in the late 1920s. However, our definitive understanding of these systems seems to have simultaneously declined. Edwin Hubble designed his Tuning Fork classification system around his belief that galaxies were stable and symmetrical, reducible to a linear hierarchy of just a handful of distinct species. By the 1950s, it was obvious that Hubble’s galaxy classes were woefully inadequate, and that galaxies were indeed behaving mysteriously. A decade earlier (in 1941), Erik Holmberg (1941) had modelled tidal disturbances apparent in "stellar systems which pass one another at small distances." Fritz Zwicky (1956) was the first astronomer to describe large-scale tidal effects characterising galaxies, in the form of "clouds, filaments, and jets of stars." He attributed these phenomena to ejection, caused by galaxy collisions. Viktor Ambartsumian tendered a very important alternative view, theorising the fissioning of celestial objects. This raised the possibility that galaxy-galaxy interactions and consequent tidal disturbances described by Zwicky, could well be caused primarily by the ejection of one object by another without their prior merging necessarily. Either way, they were definitely peculiar.

Neta Bahcall (1988) summarises it thus, "Still, despite the great effort and many ingenious ideas, no single theory for the formation of galaxies and large-scale structure can yet satisfactorily match all observations". Thus, it would appear, at super-galactic scales at least, redshift-distance correlations are always in some or other respect anomalous when tested against the body of theory.

3.2. Quasars. In 1963 Alan Sandage and Thomas Matthews, in a landmark fusion of optical and radio astronomy, identified Quasi-Stellar Objects (QSOs, hereafter quasars). They were properly described in terms of their spectral signature, and presented an unusual defining characteristic: Redshifts significantly higher than other objects seen on the sky. This created difficulties for physical theory because at their redshift-implied remoteness, they would, by known physics, be almost impossibly bright.

Quasars are very compact objects, typically only ~1 LY across. If they really are at their redshift distance, they would be so energetic that their luminosity becomes quite extraordinary.

If one plots quasars’ redshift against apparent brightness, as Hubble did for galaxies, one gets a wide scatter, as compared with a smooth curve for the same plot done for galaxies. This seems to indicate that quasars do not follow the Hubble law, and there is no direct indication that they are at their proposed redshift distance. In fact, if Hubble had been given the plot for quasars first, he and other astronomers probably would not have concluded the Universe was expanding.

Furthermore, the calculated charge density of quasars is in some cases so high that it would appear that photons could not likely escape the interior. This means that quasars should be radio- and X-ray-quiet. They obviously are not. Even more onerous was the precision measurement of radial expansion rate by very long baseline radio interferometry. Quasars appeared to be expanding at up to ten times the speed of light, and this poses obviously serious complications for underlying theory and Einsteinian physics. All of these quandaries about quasars indicate serious problems for theory, given their redshift-implied remoteness. However, these issues would tend to disappear if the objects were in fact closer to our point of observation. It was clear that quasars were peculiar enough to warrant further investigation to establish observationally what they actually were in the scheme of things, and where they might be located in space.

3.3. Observations and Catalogues. It would be fair to say that the controversy surrounding quasars and the implied phenomenon of intrinsic redshift may be attributed mainly to the early observational work of Dr Halton C. Arp, then a professional astronomer working at the major West Coast observatories of the USA. His interest in the astronomical distance ladder, stemming from his doctoral work with Edwin Hubble and subsequent 2-year stint observing Cepheids in South Africa, brought redshift into focus. In 1965, two oddities caught his interest: First, galaxies appeared to be in turmoil, showing signs of great internal stress and presenting themselves in ways that could not neatly be accommodated on Hubble’s Tuning Fork; and Second, an unusual prevalence of quasars, in pairs or more, aligned closely across active (Seyfert-like) galaxies. Sandage collaborated with de Vaucouleurs in 1958 to try to accommodate the wildly varying structural types of galaxies, and in 1966, Arp published a collection of these images in his Atlas of Peculiar Galaxies.

The furore that followed these discoveries split the astrophysical community. Most astronomers declared that close alignment of quasars with AGN was just chance, line-of-sight coincidence with no statistical or physical significance. Others argued that modification to the model (warm dark matter, top-down structure evolution) would allow observed structures to be preserved (Gibson et al., 2007). A small minority took an alternative view, amongst them (besides Arp) Margaret and Geoffrey Burbidge, Fred Hoyle, Jayant Narlikar, and Jack Sulentic.

After he was banned from the West Coast observatories in the early 1980s, Dr Arp took up employment at the Max Planck Institut für Extraterrestrische Physik (MPE) in Germany, where he was able to continue acquiring images in X-ray of objects he had previously observed optically. The MPE’s X-ray telescope, says Arp, "picked out the most energetic objects with ease, and the telescope was still small enough so that it had sufficiently large field to include the crucial objects which were related to the central progenitor galaxies" (Arp, 1998a).

The first volume, The Atlas of Peculiar Galaxies, lists 338 disturbed galaxies. They are known as the Arp galaxies, and have Arp numbers from 1 to 338 in the order presented in the atlas. Arp’s subsequent publications continued to display observational evidence of these associations, now improved by advanced instrumentation to include more detail than just tight angular spread. This led ultimately to his Catalogue of Discordant Redshift Associations (Arp, 2003).

Up to then, the samples available to Dr Arp had been limited in scope and detail, but contemporary large-scale cosmic surveys, prominently the Sloan Digital Sky Survey (SDSS), immediately introduced millions of objects to the field of study. Amongst them were more than 40 000 positively identified quasars.

The two deep field surveys are also invaluable sources of redshift data. The 2dF Galaxy Redshift Survey (2dFGRS) lists 250 000 galaxies, and the 2dF Quasar Redshift Survey (2QZ) examines 25 000 quasars. In the words of Arp and Fulton, "The resulting collection of objects can be analysed to obtain the average numbers of galaxies and quasars per square degree as shown in Table 1. The subject count records the occurrence of galaxies and quasars inside a circle of radius 30’ around each galaxy and the background count records the occurrence of galaxies and quasars in a concentric annulus of equal area enclosing the subject circle" (Arp & Fulton, 2008).

The analysis of possible anomalies in the QSO distribution of the Flesch & Hardcastle catalogue (López-Corredoira, et al. 2008), gives the scope of that collection: "Flesch & Hardcastle present an all-sky catalogue with 86 009 optical counterparts of radio/X-ray sources as QSO candidate." Again, A Catalogue of M51 type Galaxy Associations (Jokimäki, Orr, & Russell, 2008) discusses the need for further investigation: "A catalog of 232 apparently interacting galaxy pairs of the M51 class is presented. Catalog members were identified from visual inspection of multi-band images in the IRSA archive…It was found that only 18% of the M51 type companions have redshift measurements in the literature. There is a significant need for spectroscopic study of the companions in order to improve the value of the catalog as a sample for studying the effects of M51 type interaction on galaxy dynamics, morphology, and star formation. Further spectroscopy will also help constrain the statistics of possible chance projections between foreground and background galaxies in the catalog. The catalog also contains over 430 additional systems which are classified as ‘possible M51’ systems."

4. FIELDS OF STUDY

4.1. Statistical distribution. Halton Arp and colleagues found that three aspects of quasar distribution were anomalous: Their distribution amongst other objects, that is, the 2-D density of quasars on the sky, showed an inordinate prevalence of quasars paired in close (angular) proximity across Active Galactic Nuclei; objects apparently physically associated in space had significantly varying redshifts; and the asymmetrical concentrations of isophotes on AGN/quasar maps indicated that the quasars were moving away from the AGN, suggesting ejection.

Dr Arp has to date published 4 volumes besides his many papers and articles, 3 in book form. All are in effect catalogues of his observations, and they contain hundreds of examples. It is not practicable to present here an analysis of each case, so three examples are presented to illustrate the principles being put forward. It is interesting to note Arp’s use of the collective noun "family" in his recent work; it emphasises the important increase in power and resolution of modern surveys. From the first tentative observed alignments of pairs of quasars in the 1960s, we are now introduced to groups of ten or more closely gathered around active galaxies.

4.1.1. NGC 3516. In 1997, Halton Arp, together with a team of Chinese astronomers, published a landmark paper, Quasars around the Seyfert Galaxy NGC3516 (Chu et al., 1997). Arp has described this system as the "Rosetta Stone" of Intrinsic Redshift. He says, "We report redshift measurements of 5 X-ray emitting blue stellar objects (BSOs) located less than 12 arc min from the X-ray Seyfert galaxy, NGC 3516. We find these quasars to be distributed along the minor axis of the galaxy and to show a very good correlation between their redshift and their angular distance from NGC 3516. All of the properties of the high redshift X-ray objects in the NGC 3516 field confirm the body of earlier results on quasars associated with active galaxies. We conclude that because of the number of objects in this one group, the evidence has been greatly strengthened that quasars are ejected from nearby active galaxies and exhibit intrinsic redshifts."

4.1.2. AM 2230-284 Large Quasar Family. This striking example of a family of 14 quasars (reduced to 7 by magnitude constraints) gathered around the central galaxy AM 2230-284 is examined in one of Arp’s most recent studies (Arp & Fulton 2008a). "In order to work with a manageable number of cases…I was asked to excerpt from the most constrained test a list of the families with the largest number of detected companions. The list supplied 44 galaxies with 7 − 9 such companions. Glancing through these associations revealed the surprising appearance of families in which many of the quasar companions were strikingly similar in redshift. In one case the redshifts of all 7 quasars within a radius of d = 30 were closely the same…The fact that there are so many quasars all of nearly the same redshift around this galaxy marks them as being associated with a high degree of probability (…) There are specific properties of this association that are predicted from the ejection model for quasars by Narlikar & Arp (1993). Briefly summarized they are:

• QSOs are ejected in opposite directions conserving linear momentum. Figure shows 7 QSOs with positive (presumably Doppler) velocity shifts and 7 with negative shifts.

• The mean approaching and receding ejection velocities are very much the same. Extension along the lines of ejection can be slowed or deviated by moving individual QSOs around but the average usually stays closely balanced.

• The parent galaxy is an Arp/Madore peculiar galaxy. It is moderately bright at B = 17.33 mag. Its peculiarity is its compactness (high surface brightness) usually an indicator of active physical processes.

• (Karlsson Periodicity)."

The peculiarity of this system typically extends also to the rate at which it expands intrinsically. Radial expansion at 3600 km s^-1 is measured, which includes a significant ejection component. Conservatively, we may say that V_exp << 3600 km s^-1. We may then check to see if it matches the expansion rate expected if it really were at its redshift-supposed distance.

Arp says, "It is interesting to calculate what the rate of expansion would be if the cluster were at its conventional redshift distance. First of all, how far away would it be? If the velocity of light is taken to be 300, 000 km/s, then the redshift z = 2.149 is v/c = .817, v = 245, 100 km/s. Using the Hubble constant H_o = 55 km/s/Mpc r = 4, 456 Mpc = the distance to the cluster. D = 181 Mpc = the diameter of the cluster. Hence the cluster should be expanding with 9, 955 km/s. But only 3, 600 km/s is measured and most, if not all, of that is deemed ejection velocity. At the conventional redshift distance, however, just the expansion of space should imprint nearly 3 times as much front to back expansion velocity than actually measured for this quasar cluster."

4.1.3. The Quasars around NGC 5985. In Redshifts of New Galaxies Arp (1998b) states "(It) shows one of the most exact alignments of quasars and galaxies known. Attention was drawn to this region when it was discovered that a very blue galaxy in the second Byurakan Survey had a quasar of redshift z = 0.81 only 2.4 arcsecs from its nucleus. Even multiplying by 3 x 10⁴ galaxies of this apparent magnitude or brighter in their survey they estimated only a chance proximity of 10⁻³. A combined numerical probability of the configuration gives a chance of around 10⁻⁹ to 10⁻¹⁰ of being accidental. Nevertheless several peer reviewers recommended against publication on the grounds that the accidental probability was ‘greater’ than this. But, of course, several dozens of cases of anomalous associations had been reported since 1966 with chance probabilities running from 10⁻⁴ to 10⁻⁵. What is the combined probability of all these previous cases? And what is the motivation to claim each new case is ‘a posteriori’?"

4.2. Physical Association in Specific Systems. Meanwhile, the original observations catalogued by Dr Arp had prompted open enquiry by a number of astronomers in various fields of study. At the Instituto de Astrofisica de Canarias, Martín López-Corredoira and Carlos Gutierrez (hereafter L-C & G) studied individual systems to try to establish the presence of evidence supporting or refuting physical associations and material connections between objects in apparent proximity incompatible with their respective redshifts.

In their paper, Research on Candidates for Non-Cosmological Redshifts López-Corredoira and Gutierrez (2006), reported that of the 12 they were permitted to observe, fully half were found to contain definite anomalies. "For about 5 years, we have been running a project to observe some of these cases in detail, and some new anomalies have been added to those already known; For instance, in some exotic configurations such as NGC 7603 or NEQ3, which can even show bridges connecting four objects with very different redshifts, and the probability for this to be a projection of background sources is very low."

4.2.1. Markarian 205. The classic case, featured on the covers of all Arp’s books, is the bridge linking NGC 4319 and the quasar Mrk 205. Arp published the original images in 1972. In the early 1980s, Dr Jack Sulentic debunked two much-cited papers that claimed the observed bridge simply did not exist, and in 2007, he wrote: "The papers H. Arp and I wrote have never been refuted in the literature.: In the Hubble Space Telescope (HST) image, Sulentic says, "You can see the narrow core in the connection, which HST is able to detect because of its excellent resolution. It is seen exactly where we found it in the earlier studies…Hubble Space Telescope has in fact, confirmed our earlier work."

4.2.2. NGC 7603. López-Corredoira & Gutierrez, (2002), studied the field surrounding NGC 7603. It is particularly interesting because it is one of the cases where filamentary connections appear between objects of different redshift. In 2004, they revisited the study (López-Corredoira & Gutierrez, 2004). The authors presented new evidence from this specific set of observations, particularly concerning two knots in the filament connecting NGC 7603 (z = 0.029) and the QSO NGC 7603B (z = 0.057).

4.2.3. MGC 7-25-46, NGC 7319, and Stephan’s Quintet. . In Galianni et al., (2004) the authors presented observational evidence that a strong X-ray source (an Ultraluminous X-ray Source or ULX) with relatively high redshift (z = 2.114) lay in the foreground of NGC 7319, an active galaxy with relatively low redshift (z = 0.022). Several tests were conducted to determine whether or not it lay in the foreground, and results indicated that it most likely was. López-Corredoira and Gutierrez (2006) point out the connections linking elements in the system.

4.3. Redshift Survey of Local Galaxies. David G Russell used the Tully-Fisher Relation (TFR) to identify those galaxies in the Virgo Cluster that were physically bound in the cluster, and then compared their mean redshift values. The Tully Fisher Relation describes an empirically derived correlation between the spin rate and luminosity of certain classes of spiral galaxy. It is an extremely robust ratio, remaining tight over at least 7 magnitudes, which represents a factor of 600 in luminosity. It follows the simple theorem that spin rates are proportional to mass; mass in galaxies translates into stellar population; and stars are what give a galaxy its shine. If the intrinsic luminosity of the galaxy is known, comparison with apparent luminosity will give distance from point of observation via the inverse square law for light dissipation. Doppler shifts measured at the approaching and departing limbs of sufficiently oblique galaxy disks deliver a reliable value for rotation rate, and then intrinsic surface brightness can be estimated via the TFR.

In 60 years of use, the TFR principle has entrenched itself as a major component in the extragalactic distance scale, and is widely regarded as the second most reliable measure of remoteness at that scale. Russell (2003) was the first of a series of papers on TFR calibrations of both B-band and I-band in spiral galaxies in the Virgo cluster. Assuming a Hubble Constant of 72 km sec^-1 Mpc^-1, Russell identified excess redshifts in normal ScI galaxies that were clearly non-cosmological and consistent with Arp’s intrinsic redshift hypothesis. In addition, he found that giant Sab/Sb galaxies in the same cluster showed evidence of intrinsic redshift expressed as extreme negative motion. Russell followed with two more papers (Russell 2004 & 2005a).

4.4. Large-scale structure: The "Finger of God" and Kaiser Effect Anomalies in Galaxy Clusters. J. C. Jackson (1972) found an observational effect in galaxy distribution data that caused clusters of galaxies to appear elongated when expressed in redshift space, taking on the appearance of "fingers" pointing towards Earth. The virial association of high velocities in clusters with their gravitation distorts the Hubble redshift relationship, and consequently, distance measurements are inaccurate, that is, anomalous according to the model.

N. Kaiser (1987) revealed a related but smaller effect occurring in even larger structures. These "Pancakes of God" are attributed to line-of-sight distortion unrelated to distributions predicted by the virial theorem. They are thought to arise instead from infall motions of galaxies as the cluster forms, based on the assumption that high-redshift objects are nascent. Notwithstanding the evolutionary explanation and the somewhat arbitrary scalar cut-off of virial distribution, the redshift/structure relationship is anomalous. Furthermore, redshift-mapped large structures give anomalous results in terms of the Cosmological Principle, a fundamental requirement of the Standard Model of Cosmology (Bahcall 1988).

5. PERIODICITY

In 1967, Burbidge and Burbidge detected what appeared to be a quirky statistic in the redshifts of quasars: A preferred value of z = 1.95. In 1971, by which time the quasar database had expanded significantly, J. G. Karlsson established that quasar redshifts do indeed have preferred peaks, given by the formula (1 + z₂)/(1 + z₁) = 1.23, and tend to fall into the series z = 0.061, 0.30, 0.60, 0.91, 1.41, and 1.96. This phenomenon was verified by W. G. Tifft in a series of studies from 1976 to 1997, referenced in the supporting paper by Bell, Comeau, and Russell (2004). Burbidge and Napier (2000), Bell and McDiarmid (2006), and Arp and Fulton (2008b), find distinct peaks out to higher redshifts, which was predicted by the formula but not observed prior to their studies.

The notion of periodicity was countered by several studies which found no unusual periodicity in wide-area surveys, leading to the suggestion that the preferred peaks were local effects, caused possibly by structure in the direction of the galactic North Pole. However, López-Corredoira (2009) points out that while the redshift periodicity is not apparent using a base z = 0 (point of observation), it is clearly there if the redshift of the nuclear galaxy in each system is taken as the base. Hartnett (2009) reports that regardless of any interpretation of the meaning of the redshifts, and aside from any cosmological assumptions, that there is a significant periodicity in the SDSS quasar redshift abundance data.

6. PROPER MOTION AND RADIAL EXPANSION

Whilst it is as a distance measure not quantitatively exact by any means, proper motion is nevertheless a good indicator that the object under review cannot be very far away. The first schedule of proper motions for quasars was compiled in 1969 by Luyten.

Table 1: A table of proper motions for 40 quasars extracted by Varshni and Talbot from data compiled by W. J. Luyten (University of Minnesota, 1969) and included in the QSO catalogue by Hewitt and Burbidge (1993). (With permission from the website www.LaserStars.org).

The lateral motion of quasars projected to their redshift-given distances can lead to anomalies in the form of superluminal motion. Varshni (1977) presented results for three examples of quasars with well-established redshift values, returning velocities of 760c, 5200c, and 2300c, respectively.

Another difficulty for quasar redshift-distance is the measurement of the speed of jets. This too is proper motion, and is therefore a real effect. Over a period of 5 years from 1979 to 1984, Biretta measured the ejection of material from the quasar 3C 345. The increase in angular separation is directly observed and measured, and means that the system is allegedly expanding transversely at a physical rate of 7 times the speed of light.
Figure 1: The angular separation between 1979 (left) and 1984 (right) of host and ejected material in the quasar system 3C 345. The direct linear rate of departure is a function of remoteness. (Image courtesy of Dr Y P Varshni and John Biretta, STScI).

7. GRAVITATIONAL LENSING

The hypothesis is that a massive foreground object, for example a galaxy or cluster of galaxies, could if aligned correctly with a remote background object like a quasar, act as a lens, either focussing the image in the foreground or producing multiple identical images of the background object in an "Einstein Ring" around the lens itself. This could in principle explain the formations described by Arp and others of quasar families encircling nuclear galaxies.

However, there are several caveats, leading to the elimination of some already heavily-cited examples as lensing candidates. The quasars "encircling" Seyfert galaxies are proposed as multiply-lensed images of a single remote background quasar. Arp and López-Corredoira have independently found that the suggestion is questionable (López-Corredoira & Gutiérrez, 2006).

Several questions in respect of microlensed quasars raise themselves, especially that the multiple images should all have identical optical properties if they are indeed renditions of the same source object. Garsden & Lewis (2009) suggest an answer to why they are not.

Luyten discovered the high apparent lateral motion of quasars in the late 1960s, and tables of data amplifying the evidence were compiled by Hewitt and Burbidge in 1993, and later still by Varshni (cited in §6 above). This is significant in the assessment of lensing candidates. If one visualises the geometry of gravitational lensing, clearly the background and foreground objects have to line up exactly. High proper motion of quasars means that the precise longitudinal alignment of quasar and galaxy cannot maintain its integrity for more than a decade or two at most. We have precise measurements of quasar systems going back more than 40 years, and lensing candidates remain intact. This is anomalous to the model.

The Einstein Cross is a system of 5 related objects with the proper name G2237+0305. It has become the best publicised example of gravitational lensing to date. The formation is clearly symmetrical—four satellite quasars of near-identical redshift surrounding a central galaxy. However, strong evidence of a physical connection is apparent in the spectroscopy. Isophotes overlaid by Arp and Crane (Arp, 1998a, pp 172—175) revealed that all four quasars were physically joined to the parent galaxy by matter bridges, removing the possibility that the system is a lens. This was later confirmed spectroscopically by Howard Yee. Notwithstanding the above, gravitational lensing remains the strongest alternative to Arp’s quasar ejection hypothesis. However, since lensing is a possible explanation in only a very small fraction of observed quasar-AGN associations, the matter remains unresolved.

8. DISCUSSION & CONCLUSION

The physical association between objects with different redshifts has been made clear in observation. If we find in observation that the Hubble redshift relationship is subject to notable exceptions, which certainly appears to be the case, it is to be hoped that they would attract careful scrutiny. Just one such exception, reasonably verified, would suffice to cast doubt upon the reliability of redshift/distance theory, with far reaching consequences for astrophysics.

ACKNOWLEDGEMENTS: None of those mentioned here necessarily agrees or disagrees with any argument or inference made in this paper. As always, Martin Lopez-Corredoira has taken time to share his experience with me, and review my work with a friendly, critical eye. Dave Russell is ever courteous, never too busy to swap data and ideas. Halton Arp has been magnanimous as usual, giving me free rein with his published work. Geoffrey Burbidge offered some incisive advice of a more general nature, which was gratefully received. Sincere gratitude is due also to the referees appointed by the Journal of Cosmology, who contributed in no small measure to an improvement in form and effectiveness of this review. This paper is dedicated to my late mentor and teacher, South African solar astronomer Robert Bennett Blore, to whom my debt is incalculable.