A model of compact nuclei of galaxies as spherically-symmetric star clusters is proposed. A concept of the equation of state for star clusters in statistical equilibrium is introduced (galactic nuclei are systems in statistical equilibrium if their age is of the order of the age of the Universe). It is shown that a statistically equilibrium star cluster is described by the equation of state of a polytrope P = aρ3, and with its help the main parameters of compact nuclei of galaxies are calculated. The formula M = 2.524GR5/a for mass M and radius R of the cluster is derived.

GHz peaked spectrum radio sources (GPS) are believed to be a subclass of compact steep spectrum radio sources (CSS) with high frequency spectral indices α < −0.5 (5 ˜ vα), linear sizes of pc to kpc scale and turnover spectra near 1GHz. Due to the work of many radioastronomers during the past two decades many properties of CSS and GPS radio sources at present are known (O'Dea,C.P. et al.1998, and references therein).

It is expected that at explosion of Supernovae the mechanism of producing a shock wave is based on subatomic interactions, and the remnant of the supernovae explosion can be a hybrid quark-hadron star. Since the temperature in the centre of collapsing stars reaches of order T = 6 − 8 · 1010K and density electrons from the top of the Fermi sea can be captured and convert protons into neutrons via e− + p → n + ve. The capture of electrons results in a neutronization burst (V.S. Imshennik 1988). Core collapse of the progenitor star becomes essentially a free fall with a time scale . When the central density of the core reaches supernuclear densities the repulsive QCD forces becomes essential. This can bring about manifestations of quark-hadron phase transitions (A. Dar 1997). After the explosion, from the remaining matter is probably formed a hybrid star.

We obtain the global transonic solutions by solving numerically a set of equations describing advection dominated accretion flows around black holes. We find that the sonic points can locate themselves at almost any radius, independent of the viscosity parameter α and the polytropic index γ.

The example of M87 shows that AGN are the most powerful units of protogalactic matter, which has built the large scale Universe during parts of the first second of the Big Bang. For fulfilment of such a mission it had to possess properties of elementary particles.

This is a short review of recent studies and reports on interacting galaxies and binary galaxies. Early studies were primarily made at optical wavelengths, but recent ones have concentrated on observing HI at λ21 cm. Application of the Virial Theorem to these observations indicates M/L values of the binary systems of ≲50, suggesting the existence of moderate halos around spiral galaxies.

Observations increasingly demonstrate the spatial association of high redshift objects with larger, low redshift galaxies. These companion objects show a continuous range of physical properties - from very compact, high redshift quasars, through smaller active galaxies and finally to only slightly smaller companion galaxies of slightly higher redshift. The shift in energy distribution from high to low makes it clear that are seeing an empirical evolution from newly created to older, more normal galaxies.

In order to account for the evolution of intrinsic redshift we must conclude that matter is initially born with low mass particles whose mass increase with time (age). This requires a physics which is nonlocal (Machian) and which is therefore more applicable to the cosmos than the Big Bang extrapolation of local physics. Ambartsumian's “superfluid” foresaw some of the properties of the new, low particle mass, protogalactic plasma which is required, demonstrating again the age-old lesson that open minded observation is much more powerful than theoretical assumptions.

Since the ejected plasma, which preferentially emerges along the minor axis of the parent galaxy, develops into an entire galaxy, accretion disks cannot supply sufficient material. New matter must be created within a “white hole” rather than bouncing old matter off a “black hole”.

A number of monitoring observations of continuum emission from Active Galactic Nuclei (AGNs) have been made in optical-X-ray bands. The results obtained so far show (i) random up and down on timescales longer than decades, (ii) no typical timescales of variability on shorter timescales and (iii) decreasing amplitudes as timescales become shorter. The second feature indicates that any successful model must produce a wide variety of shot-amplitudes and -durations over a few orders in their light curves. In this sense, we conclude that the disk instability model is favored over the starburst model, since fluctuations on days are hard to produce by the latter model.

Inter-band correlations and time lags also impose great constraints on models. Thus, constructing wavelength and time dependent models remains as future work.

New values of the frequencies of SNe are presented and discussed in relation to their use as SF indicators. The rate of core-collapse SNe is correlated to the colors and the FIR excesses of the parent galaxies in the sense that galaxies with blue colors and strong infrared excess have higher occurrence of type II and Ib/c SNe than other galaxies. This is in agreement with the expectation that they contain a higher fraction of massive stars. Instead no correlation is present for SNIa. The SN frequency does not correlate with the galaxy activity probably because searches are unable to discover SNe in the nuclear regions of galaxies.

A number of SNe with spectra similar to those of AGN exist. Their characteristic features are explained with explosion of SNe in dense environments, reminding of cSNR's invoked in the starburst model for AGNs. Some recent, peculiar SNe seem linked to GRB's opening the possibility that at least some GRB's arise from this kind of stellar explosion.

We report the discovery of a new double image gravitational lens system B1030+074 which was found during the Jodrell Bank - VLA Astrometric Survey (JVAS). We have collected extensive radio data on the system using the VLA, MERLIN, the EVN and the VLBA as well as HST WFPC2 and NICMOS observations. The lensed images are separated by 1.56 arcseconds and their flux density ratio at centimetric wavelengths is approximately 14:1 although the ratio is slightly frequency dependent and the images appear to be time variable. The HST pictures show both the lensed images and the lensing galaxy close to the weaker image. The lensing galaxy has substructure which could be either part of the galaxy or a companion object. We have modeled B1030+074 using a Singular Isothermal Ellipsoid that yielded a time delay of 156/h50 days. This lens is likely to be suitable for the measurement of the Hubble constant.

Persic & Salucci (1995; hereafter, PS) reduced raw Hα data from a large sample of southern sky spirals obtained by Mathewson, Ford & Buchhorn (1992), to present 900 Hα, rotation curves. It is found that a power-law, Vrot = A Rα, imposes extremely detailed correlations between the kinematic and the luminous properties of the galaxies through the model parameters (A, α); this law can be inverted to give a form of super Tulley-Fisher relationship for the determination of absolute magnitudes in terms of velocity information. Furthermore, there is very strong evidence suggesting the existence of discrete kinematic states for rotation curves (RCs hereafter) - which ultimately implies the luminosity evolution of galaxies to be similarly constrained to occupy discrete states.

The problem of the activity of extragalactic objects is one of the main problems of current astrophysics. There are many manifestations of activity but the photometric and polarimetric variability in IR, optical, UV and X-ray regions is probably one of the most important. The sources responsible for the variability are placed in the nearest neighbourhood of a central engine. Clarifying the nature of these sources might give a tool to the solution of the problem of nuclear activity in general.

A self-consistent analysis of near-UV, HST/FOC images of the elliptical galaxy NGC 4552 is used to show that its central spike has brightened by a factor ˜ 4.5 between 1991 and 1993, and has decreased its luminosity by a factor ˜ 2.0 between 1993 and 1996. A strong UV continuum over the energy distribution of the underlying galaxy is concurrently revealed shortward of λ ˜ 3200 Å by our FOS spectra extending from the near-UV to red wavelengths. Nuclear emission-line profiles of both permitted and forbidden lines are best modelled with a combination of broad and narrow components, with FWHM of ˜ 3000 km s−1 and ˜ 700 km s−1, respectively. Current diagnostics based on the emission line intensity ratios definitely places the spike among AGNs, just at the border between Seyferts and LINERs. This evidence argues for the variable central spike being produced by a modest accretion event onto a central massive black hole (BH), with the accreted material having possibly being stripped from a star in a close fly-by with the BH. In this regard, one has to look at NGC 4552 as the faintest known AGN.

Based on the CCD photometric and spectroscopic observations taken with 1.23 m and 2.2 m telescopes at the German-Spanish Astronomical Center in Calar-Alto (Almeria, Spain) as well as with the 1.54 m telescope at the European Southern Observatory (La Silla, Chile) some emission-line galaxies (ELGs) surprisingly have been found in Shahbazian compact groups of galaxies (SHCGs) by our research group.

Morphology of the nuclear region of the component NGC 7770 indicates that it has a complicated structure in the B-band, while the V-band shows a double nuclear structure. The brightness and color of the nuclear condensations are given. Detailed photometric analysis of this component including luminosity profiles along major and minor scans as well as position angle and ellipticity curves is obtained. Integration and decomposition of the luminosity profiles are also performed. The color distribution and integrated color are also studied taking into account that the blue color together with the unusual color distribution are characteristics relevant to UV-excess galaxies. The integrated photometric parameters are also given.

The state of interaction between the components of the pair is also investigated. The peculiar features appearing in the isophotal maps, the truncation of the luminosity profile along the side of interaction and the unusual appearance of the structural profiles are discussed and considered as strong evidence for the real state of interaction between the components of the pair. A lower limit of the total orbital mass of the system is found to be Mt=1.36 × 1010 M⊙, and the total mass-to-luminosity ratio is f=0.63 f⊙.

The relative orientation of radio and optical axes of radio-galaxies has been analysed for a sample of about 300 sources. Radio major axes have a tendency to align with optical minor axes of the host galaxies for the more elongated radiosources while they appear correlated with optical major axes for the less elongated radiosources.

We report on rapid variations of the Hβ profile shape in 3C 390.3 over a period of one hour and discuss the implications for the velocity field of the BLR.

We report on rapid variations of the Hα profile in Mark 6 over a period of about one hour and the implications for the velocity field of the BLR.

Several groups of astronomers in FSU (Former Soviet Union) and European countries have started, in 1998, a cooperative spectral and broad-band optical and UV-monitoring of the nuclei of selected Seyfert galaxies and quasars (10 objects). The monitoring is to be continued until Oct. 30, 2000. The spectral optical monitoring with CCD-cameras in the spectral range λλAA4000–8000ÅÅ is being carried out at two observatories: SAO RAS, Russia (6-m and 1-m telescopes) and at Kazakhstan (70-cm telescope). The resolution is about 3–10Å, the S/N ratio is ≍50–100. The broad-band optical monitoring with BVRI filters (with a 1% accuracy at the R-band) is being done at 5 observatories. NLR and ENLR in monitored galaxies will also be investigated.