We explore how the local environment is related to the redshift, type, and luminosity of active galactic nuclei (AGN). Recent simulations and observations are converging on the view that the extreme luminosity of quasars is fueled in major mergers of gas-rich galaxies. In such a picture, quasars are expected to be located in regions with a higher density of galaxies on small scales where merger...

Several QSO pairs have been reported and their redshifts determined, where the two objects in each pair are located across an active galaxy. The usually accepted explanation of such occurrences is that the pair is ejected from the parent galaxy. Currently interpreted redshifted spectra for both the QSOs imply that both the objects are receding from the observer. However, ejection can occur towa...

1 Department of Astronomy, Faculty of Mathematics, University of Belgrade, Belgrade, Serbia, 2 Special Astrophysical Observatory, Russian Academy of Sciences, Nizhnii Arkhyz, Russia, 3 Astronomical Observatory, Belgrade, Serbia, 4 Instituto Nacional de Astrofísica, Óptica y Electrónica, Puebla, Mexico, 5 Institut fuer Astrophysik, Universitaet Goettingen, Göttingen, Germany, 6 Faculty of Scienc...

A review is given of attempts to describe nuclear properties in terms of neutron–proton pairs that are subsequently replaced by bosons. Some of the standard approaches with low-spin pairs are recalled but the emphasis is on a recently proposed framework with pairs of neutrons and protons with aligned angular momentum. The analysis is carried out for general j and applied to N = Z nuclei in the ...

We present the implementation of dusty, radiation pressure–dominated photoionization models applicable to the narrow-line regions (NLRs) of active galactic nuclei, using the MAPPINGS III code. We give a grid of the predicted intensities of the most commonly used diagnostic spectral lines in the UV, optical, and IR, covering a wide range of density, metallicity, the power-law index characterizin...

We examine the stability of feedback-regulated star formation (SF) in galactic nuclei and contrast it to SF in extended discs. In galactic nuclei, the orbital time becomes shorter than the time over which feedback from young stars evolves. We argue analytically that traditional feedback-regulated SF equilibrium models break down in the regime. We study this using numerical simulations with the ...

Recent experiments have demonstrated that the rotational alignment for the N5Z nuclei in the mass-80 region is considerably delayed as compared to the neighboring NÞZ nuclei. We investigate whether this observation can be understood by a known component of nuclear residual interactions. It is shown that the quadrupole-pairing interaction, which explains many of the delays known in rare-earth nu...

In the case of gravitationally-lensed quasars, it is well-known that there is a time delay between occurrence of the intrinsic variabilities in each split image. Generally, the source of variabilities has a finite size, and there are time delays even in one image. If the origin of variabilities is widely distributed, say over > ∼ 100 pc as whole, variabilities between split images will not show...

We follow the evolution of the Black Hole mass function in the assumption that mass accretion onto a massive BH is the powering mechanism of AGN activity. With reasonable assumptions suggested by current knowledge, it is possible to reproduce the Black Hole mass function derived from local bulges. In particular it is found that the majority of the mass in relic Black Holes was produced during A...