We provide constraints on optically faint (I ≥ 24) X-ray sources, z > 6 AGN, Very Red Objects (VROs; I − K ≥ 4), and optically faint radio sources using the 1 Ms Chandra Deep Field North survey. We argue that the majority of the optically faint X-ray sources are obscured AGN at z = 1–3. These sources comprise up to 50% of the X-ray detected AGN. Approximately 30% of the optically faint X-ray so...

We present a summary on the discovery of active galactic nuclei in midand far-infrared deep surveys with use of the Infrared Space Observatory.

I review observational properties of low power radio loud AGN. High resolution VLBI observations allow the estimate of the jet velocity and orientation with respect to the line of sight and the determination of the Doppler factor. These data reveal rich structures, including two-sided jets and secondary components. New results on 1144+35, a giant radio source with superluminal motion are shown ...

We report on a 3600 s spectrum of GRB 021004 obtained with the Nordic Optical Telecope on La Palma 10.71 hours after the burst. We identify absorption lines from five systems at redshifts 1.3806, 1.6039, 2.2983, 2.3230, and 2.3292. In addition we find an emission line which, if due to Lyα from the host galaxy, gives a redshift of 2.3351. The nearest absorber is blueshifted by 530 km s with resp...

A radio source that faded over 6 days, with a redshift z ≈ 0.5 host, has been identified by Keane et al. (2016) as the transient afterglow to a Fast Radio Burst (FRB 150418). We report followup radio and optical observations of the afterglow candidate, and find a source that is consistent with an active galactic nucleus (AGN). If the afterglow-candidate is nonetheless a prototypical FRB aftergl...

We consider a simple model, based on currently accepted models for active galactic nuclei, for a quasi-stellar object (QSO or “quasar”) and examine the influence that correlationinduced spectral changes (“The Wolf Effect”) may have upon the redshifts of the optical emission lines. LAUR-98-417

Some aspects of theory of γ-ray production in blazar type active galaxies are discussed in context of recent observations.

The Baldwin Effect, a negative correlation between emission-line equivalent width and luminosity in active galactic nuclei, is still of interest as a diagnostic of accretion physics nearly thirty years after its discovery. This review examines recent developments in the study of correlations between line and continuum emission in AGNs, as measured both in ensembles and in individual sources.

MAGIC is presently the imaging atmospheric Cherenkov telescope with the largest reflecting surface and the lowest energy threshold. MAGIC concluded its first year of regular observation in April 2006. During this period and the preceding commissioning phase, 25 Active Galactic Nuclei have been observed and VHE γ-ray emission has been confirmed by 4 of them. Two more AGNs have been detected as γ...