The adiabatic spherical expansion model of radio source outbursts has been applied to several outbursts in the quasi-stellar sources 3C 273 and 3C 454.3 and the Seyfert galaxies 3C 84 and 3C 120. Considering the simplicity of the model, it represents the data exceedingly well in a number of outbursts. The times of origin of the outbursts, the electron energy distribution indices, and the acceleration of the expansion parameters have been derived. Estimates of the sizes and magnetic fields of the outbursts have been made.

These results are part of a paper to be submitted to the Astrophys. J.

Preliminary results are reported of a long-term program to test models of variable radio sources by direct observations of diameter changes. Although further confirmation is needed, increase in angular diameter attributed to a centimetric component of 3C 279 found in 1966 implies relativistic expansion with α ≳ 2.

In order to sort out events taking place in variable sources it is necessary to observe frequently and at many wavelengths, especially at short wavelengths.

I report here work done at Jodrell Bank by Mr John Gilbert and myself at a wavelength of 49 cm, on the degree of linear polarization, m49. For most sources the polarization is considerably reduced from its short wavelength value. We presume that most of this depolarization is by Faraday rotation, or rather by Faraday dispersion, between different parts of the source.

Accurate relative spectra for 300 radio sources from the Parkes catalogue have been measured and a statistical study made of their relation to class of optical identification and to other radio properties. Individual spectra and their time variations have also been investigated.

The results support the contention that radio sources for which no identification appears on the Palomar Sky Survey prints may be galaxies more luminous at radio frequencies than those which are identified. From a study of QSOs, radio galaxies and these blank field objects, it appears (a) that with increasing radio luminosity compact components are more often found, their presence being indicated by synchrotron self-absorption at low and high frequencies, by flat, variable spectra at high frequencies, and by interplanetary scintillations; and (b) that where no compact component contributes to the spectrum at high frequencies, many spectra steepen with increasing frequency, an effect which may be more marked for the more radio luminous objects.

Detailed analyses of the time variations in the compact components of 22 variable sources are generally consistent with the adiabatically expanding, uniform sphere model of Shklovsky, Kellermann, van der Laan and others. The model was modified to include relativistic expansion according to the formulae given by Rees and Simon. The results suggest that these components have evolved within months or years, have linear dimension of 0.1 to 100 pc and magnetic fields of 1 to 10−4 G. Some spectra at frequencies above 5000 MHz suggest non-adiabatic expansion which may be the result of continued injection of energy into an expanding region.

M87 (Virgo A, 3C274) has been observed at 5 GHz with the Cambridge One-Mile telescope, with a resolution of 6.5 arc sec. These observations do not include the extensive halo but show that the central region of the source consists of at least three components. The central of the components is unresolved and appears to coincide with the optical nucleus, the outer pair extending from a point about 5 arc sec south of the optical nucleus. These components are unresolved perpendicular to their extension axes. The north preceding component is related to the optical jet but is more extended.

Using a Lallemand electronic camera, optical identifications for several 3CR radio sources have been made. Photometry has been obtained for objects as faint as B ≃ 21.25. It is suggested that some of the identifications may have redshifts in excess of z = 3.

A study of twelve compact radio sources whose radio spectra show pronounced peaks at centimetre wavelengths has been made using the Cambridge one-mile radio telescope operating at a frequency of 5 GHz. For each of these sources we have measured accurate positions to closer than one arc sec and determined upper limits to their angular sizes.

A search for optical identifications using the prints of the Sky Survey has revealed probable candidates for eleven of the twelve sources, an unusually high success rate. Of the suggested identifications, three are galaxies (OC 328 = 4C 31.04, VRO 20.04.02, OQ 208), and eight are possible or confirmed QSOs (NRAO 140 = 4C 32.14 = OE 355, OI 315, P 0735 + 17 = VRO 17.07.02, OI 363, OJ 287 = VRO 20.08.01, OK 290, OR 103, DA 406). Details are given by G. M. Blake, Astrophys. Letters6, 201 (1970).

An attempt was made to detect the redshifted Hi line in absorption in the quasi-stellar sources 3C 273 and 1510 - 08 and in the N-galaxies 3C 120 and 3C 371. The Seyfert galaxies NGC 1068 and NGC 1275 were also searched for Hi in absorption as well as in emission. Although no lines were detected, it was possible to place upper limits on the column density of Hi in all these objects, as well as upper limits on the mass of Hi in the Seyfert galaxies observed.

In collaboration with Messrs P. Chamaraux and R. Lauqué we have observed five objects of compact type or with compact parts at Nanĉay with the 21-cm line of neutral hydrogen. Details will be found in Astron. Astrophys.8, 424, 1970.

The four Seyfert galaxies with systemic velocities of less than 2000 km s−1 have been observed at 21 cm with the Jodrell Bank 250-ft telescope and a 5 MHz overall bandwidth setting of the 256 channel auto-correlation spectrometer. Relatively strong signals of 0.5 f.u. are observed in NGC 1068 and 4151, while less well-determined signals of ∼ 0.25 f.u. and covering a wide velocity range are seen in both NGC 3227 and 4051. Measures of the systemic velocity, velocity width and Hi mass are obtained, the Hi mass/L being normal for galaxies of their Hubble type.

The 21-cm wavelength radiation from neutral hydrogen in NGC 1068, NGC 3227, NGC 4051 and NGC 4151 has been observed with the large radio telescope at Nanĉay, France. Since the angular sizes of these galaxies are of the same order as the telescope right ascension beam-width, no information on the angular distribution of the neutral hydrogen was obtained. However the radial velocity distribution of the total hydrogen (the ‘integrated profile’) of the whole galaxy was measured for each of the four galaxies. The hydrogen masses and total masses can be calculated from these profiles using simple models of galaxy shapes and rotation curves.

Optical spectra sometimes show evidence for explosive phenomena and radial outflow of gas in the central regions of Seyfert galaxies. We have examined the integrated radio profiles for indications of large-scale radial motions of neutral hydrogen in two ways. First, for all four galaxies observed, we compare the ratios of hydrogen mass to total mass with the values obtained from other galaxies (not Seyfert) of the same morphological type. Second, for these galaxies where the optical data are available, we compare the estimates of total mass obtained from the optical spectra with the estimates based on the width of the radio profile.

We conclude from these comparisons that the integrated profile of NGC 1068 is unusually broad. One possible interpretation which is qualitatively consistent with the optical data is that an appreciable fraction (about ⅓) of the neutral hydrogen content of NGC 1068 is moving radially outward with velocities of about 200 km s−1 An indication of similar phenomena (although less extreme) is obtained for NGC 4051. The widths of the integrated profiles of NGC 3227 and NGC 4151 do not seem unusual.

Observations with the Owens Valley Radio Observatory interferometer show that BL Lac has a 21-cm hydrogen absorption line, produced by a local intervening cloud. The line is centered on zero velocity (LSR), has a width of about 5 km s−1, and shows an optical depth of 0.5. BL Lac is at galactic latitude b= −10°. No firm distance limit is possible, but such clouds are, typically, 100 pc apart. This observation is consistent with BL Lac being an extragalactic object. Other observations leading to a similar conclusion are of rotation measure (MacLeod and Andrew, 1968) and of reddening (Bertaud et al., 1969).

Because of the anisotropic character of the generation of relativistic particles and synchrotron emission of active galactic nuclei and QSS it should be expected that ‘magnetoids’, the plasma bodies which are responsible for such generation, will attain large momenta. Therefore, magnetoids should be pushed out of nuclei with high velocities. This mechanism can explain several puzzling effects which are observed in the Metagalaxy, e.g. the jet in NGC 4486, connections between some galaxies and QSS and the total positive energy of some clusters of galaxies.

The rotation of massive objects with magnetic fields may provide the highly efficient means of energy conversion required to explain the high luminosity of compact objects. Several variations of the ‘massive rotator’ model are discussed.

The proposition for consideration is:

A QSO is an approximately standard object: it has an approximately standard history consisting mainly of an increase of optical brightness to a very high peak, and a subsequent decline. I suggest that the history has a relevant duration of about 106 yr, and that the total increase of brightness is by a factor about 103, while the mean brightness is of the order of 1% of the peak brightness (so that the peak is rather sharp).

In this synchrotron radiation model, the essential feature is that the basic form of the theoretical continuum is a characteristic of the energy evolution of a single electron. The model may be applied to sources containing high magnetic field regions where electrons have radiation lifetimes short compared with typical observation times; the electrons are generated in condensations of material which also amplify magnetic fields to values required for the emission of optical synchrotron radiation. A more specialized version of the model can provide a description of the QSOs that is consistent with their cosmological interpretation.

This paper considers a magnetoid model for nuclei of compact objects in which repeated explosions are caused by instability in twisted magnetic fields. The derived frequency and energy of individual explosions agrees with observations.

The evolution of massive cores in the post-quasar phase is considered.

The ultimate source of energy in compact objects is investigated. The model is a highly flattened body of mass ≳ 104M⊙, supported by centrifugal force in two directions and by gas and radiation pressure in the third. The properties of this model are compared with those nearly spherical supermassive stars introduced by Hoyle and Fowler.

Observations of quasi-stellar objects and radio galaxies indicate that the total energy radiated from such objects is so large that the most likely source of energy is annihilation.

The demand for symmetry in the universe between ordinary matter and antimatter indicates that there must be equal quantities of the two kinds of matter in every galaxy. From this it seems likely that a galaxy is born as an ambiplasma body, in which separation of matter from antimatter leads to reasonably stable configurations.

The violent events observed in quasi-stellar objects are then interpreted in terms of collisions between stars of opposite kinds of matter. Such collisions are expected to occur frequently in very young galaxies with a high stellar density in the nucleus. Most of the gamma-radiation released in the annihilation will be absorbed in the gases of the colliding bodies, causing strong heating and violent explosions. Strong ionizing radiation and expanding gas clouds will give rise to the observed optical line emission. Expanding clouds of light ambiplasma will emit synchrotron radiation.