Quasar

Scientific Theory
Name	Quasars (non-cosmological interpretation)
Type	Astrophysical object / cosmological controversy
Author(s)	Halton C Arp, Geoffrey Burbidge, Jayant Narlikar, William Tifft and others
Keywords	quasar, QSO, intrinsic redshift, discordant associations, ejection, Karlsson peaks, Big Bang
Year	1963 onward

Quasars (quasi-stellar objects, or QSOs) are compact, extremely luminous objects with very large redshifts. They are the single most contested class of object in modern cosmology, and the principal battleground between standard cosmology and the critical tradition documented on this wiki.

Mainstream astronomy reads a quasar's large redshift as purely cosmological, and therefore places quasars at the greatest distances in the observable universe — making them the most luminous objects known. A substantial body of observational work, led above all by the astronomer Halton C Arp, contends that this interpretation is mistaken: that quasars are far nearer than assumed, that much of their redshift is intrinsic rather than cosmological, and that they are ejected from the nuclei of active nearby galaxies. If so, the redshift–distance relation fails precisely where cosmology most depends on it, and the Big Bang distance scale must be rebuilt.

The standard picture

On the conventional account a quasar is the nucleus of a young, distant galaxy powered by matter accreting onto a supermassive black hole. Its redshift is taken to arise wholly from cosmic expansion, placing typical quasars billions of light-years away, and requiring luminosities hundreds of times that of an entire galaxy. This is the interpretation found in textbooks and assumed by most survey work.

The case against cosmological distance

Discordant associations and ejection

Arp's central objection is that quasars are repeatedly found physically associated with low-redshift galaxies — too often, and too closely, for coincidence. He catalogued many such pairings in his Catalogue of Discordant Redshift Associations (2003), including the classic case of the galaxy NGC 4319 and the quasar-like object Markarian 205, which he argued are joined by a bridge of luminous material despite grossly different redshifts.

The most striking case came in 2005, when Galianni, Arp and colleagues reported an X-ray-emitting quasar of redshift z = 2.11 lying within a few arcseconds of the nucleus of the active galaxy NGC 7319 (z = 0.0225) in Stephan's Quintet — and apparently in front of it, seen through the galaxy's own gas. On the standard reading the quasar should be some thirty times more distant than the galaxy. Proponents regard such a configuration as very difficult to explain as chance superposition.

From this evidence Arp developed an ejection model: quasars are expelled, often in aligned pairs, from the nuclei of active parent galaxies, beginning life with a large intrinsic redshift that decreases as they age, eventually evolving into ordinary companion galaxies. On this view quasars are not the remote ancestors of galaxies but their nearby offspring.

The energy problem

Quasars vary in brightness over days to weeks, which limits the size of the emitting region to light-days or light-weeks across. If quasars are as distant as the standard interpretation requires, that tiny volume must outshine an entire galaxy by orders of magnitude. Critics have long argued that this demands implausibly extreme physics, and that the difficulty largely dissolves if quasars are much closer and correspondingly far less luminous.

Karlsson peaks: quantized quasar redshifts

Quasar redshifts do not appear to be smoothly distributed. In 1971 K. G. Karlsson reported a periodicity in log(1 + z), yielding preferred values near z ≈ 0.061, 0.30, 0.60, 0.96, 1.41 and 1.96 — the so-called Karlsson peaks. A genuine distribution of recession velocities would be expected to be continuous, so proponents read this periodicity as direct evidence of a non-velocity, intrinsic component in quasar redshift, consistent with the quantization Tifft reported for galaxies. See Redshift quantization.

Intrinsic redshift and variable mass

The mechanism most often advanced by proponents is the Variable Mass Hypothesis developed in the Hoyle–Narlikar framework and adopted by Arp: newly created matter has very low particle mass, and its atomic transitions are therefore shifted toward the red. A young, recently ejected quasar would then show a large redshift because its matter is young and light, not because it is receding at enormous speed — and that redshift would decline as the object ages. Other proposed mechanisms include tired light and plasma or wave-propagation effects. See Intrinsic redshift.

Alternative models on this wiki

Quasars are treated extensively in the literature catalogued here, from a range of non-standard viewpoints. Papers include Quasar Spectra: Black Holes or Nonstandard Models?, A Way Out of the Quasar Redshift Shambles, The Karlsson Peaks in the Quasar's Redshift Distribution as an Indication for Circling Light in a Non-Expanding Universe, Another Explanation of the Redshifts of the Pair Quasar-Galaxy NGC 7319, Cause of the Characteristics of Quasars, Are Quasars Manifesting a de Sitter Redshift?, A Survey of Anomalous Redshifts, Quasar's Gyro-gravity Behavior, Luminosity and Redshift, and Arp's own Empirical Evidence on the Creation of Galaxies and Quasars. Contributors with pages here include Halton C Arp, Robert S Fritzius and Lothar Pernes.

Mainstream objections

Standard astronomy maintains that the discordant associations are chance superpositions — with vast numbers of faint background quasars, some must appear near foreground galaxies — and that statistical re-analyses do not support the claimed excess. The redshift periodicities are attributed to selection effects and small samples. Proponents reply that the objections are applied selectively, that the alignments and connecting features are not what random projection produces, and that the resistance has been institutional as much as evidential — the case Arp set out in Seeing Red: Redshifts, Cosmology and Academic Science (1998).

See also

• Halton C Arp
• Intrinsic redshift
• Redshift quantization
• Atlas of Peculiar Galaxies
• Big Bang
• Category: Cosmology