The shape of a cusped galactic nucleus is constrained by the range of shapes of orbits in its gravitational potential. It is shown for scale-free non-axisymmetric discs that while a plausible elongated density model requires at least some orbits to spend more time near the major axis than anywhere else, both regular boxlets and tube orbits generally cross the major axis too fast for self-consis...

We discuss radio observations of a sample of radio-weak and radio-intermediate quasars which demonstrate that – just like their radio-loud counterparts – radioweak quasars too have relativistic jets in their nuclei. Moreover, a VLA survey of nearby LINER galaxies reveals a relatively large number of flat-spectrum radio cores. It is suggested that those cores are also best explained by moderatel...

In recent years satellite observations have recorded a number of point X UD\ sources in the sky. Such sources are overwhelmingly identified with medium to high redshift quasars. These quasars can now be shown to originate in low redshift, active galaxies which eject them along their minor (rotation) axis. It can be empirically demonstrated that this is how galaxies are born and evolve. The obse...

Interactions between galaxies are suggested to be a mechanism responsible for feeding Active Galactic Nuclei (AGN). Theoretical models show that interactions are an efficient way to drive gas from the galaxy to the nucleus, however, the observational evidence on this subject is controversial. Here we review results in this field, discuss possible limitations of previous studies and the importan...

We carried out a one-night optical V and near-infrared JHK monitoring observation of the least luminous Seyfert 1 galaxy, NGC4395, on 2004 May 1, and detected for the first time the intraday flux variations in the J and H bands, while such variation was not clearly seen for the K band. The detected J and H variations are synchronized with the flux variation in the V band, which indicates that t...

We present ∼ 3 resolution imaging of the z = 4.7 QSO BR1202-0725 at 900 μm from the Submillimeter Array. The two submillimeter continuum components are clearly resolved from each other, and the positions are consistent with previous lower frequency images. In addition, we detect [C II] line emission from the northern component. The ratio of [C II] to far-infrared luminosity is 0.04% for the nor...

We have surveyed an optical/IR selected sample of nearby E/S0 galaxies with and without nuclear dust structures with the VLA at 3.6 cm to a sensitivity of 100 μJy. We can construct a Radio Luminosity Function (RLF) of these galaxies to ∼ 10 W Hz and find that ∼ 50% of these galaxies have AGNs at this level. The space density of these AGNs equals that of starburst galaxies at this luminosity. Se...

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...

We present Hubble Space Telescope ACS images of 13 dust-reddened type 1 quasars selected from the FIRST/ 2MASS Red Quasar Survey. These quasars have high intrinsic luminosities after correction for dust obscuration ( 23:5 MB 26:2 from K-magnitude). The images show strong evidence of recent or ongoing interaction in 11 of the 13 cases, even before the quasar nucleus is subtracted. None of the ho...