In this review talk I discuss the important issues of AGN research and how the new generation of X-ray observatories can help to constrain the physics of AGN. I also present a biased list of the new XMM-Newton and Chandra discoveries and how they have altered our view of AGN. I also present a set of what are the new types of observations that need to be performed to make significant progress in...

The isovector M1 transitions between low-lying T=1 and T=0 states in oddodd N=Z nuclei are analyzed. Simple analytical expressions for M1 transition strengths are derived within a single-j-shell approximation for both j = l+1/2 and j = l − 1/2 cases. The large B(M1) values for the j = l + 1/2 case are attributed to quasi-deuteron configurations. The B(M1) values for the j = l − 1/2 case are fou...

Observations of Markarian 231 at 1.1 mm taken with NICMOS on the Hubble Space Telescope are described. The brightness of the object in the near-infrared, and the inherent short-term stability of the NICMOS optical and instrumental system, enables the application of special observational and analysis techniques that effectively increase high spatial resolution. By these means, we set an upper li...

We review critically the evidence concerning the fraction of Active Galactic Nuclei (AGN) which appear as Type 2 AGN, carefully distinguishing strict Type 2 AGN from both more lightly reddened Type 1 AGN, and from low excitation narrow line AGN, which may represent a different mode of activity. Low excitation AGN occur predominantly at low luminosities; after removing these, true Type 2 AGN rep...

A line photon incident in an electron-scattering medium is transferred in a diffusive way both in real space and in frequency space, and the mean number of scatterings changes as the wavelength shifts from the line center. This leads to the profile broadening and polarization dependence on the wavelength shift as a function of the Thomson optical depth τT . We find that the polarization of the ...

The multi-epoch single-survey Planck satellite data have given a rare glimpse into how the radio spectra of active galactic nuclei (AGN) evolve in time. Using Planck and simultaneous auxiliary radio data ranging from 1 GHz to 857 GHz, spectra for 104 bright northern extragalactic radio sources (most of them AGN) have been assembled; in these, the various stages of flare development can be ident...

We present preliminary results of a 25 ks XMM–Newton observation of the largest sample of Extremely Red Objects (EROs) available to date (∼450 sources), selected in a contiguous area of ∼ 700 arcmin (Daddi et al. 2000). Five of the 36 hard X–ray selected sources brighter than 7× 10 erg cm s in the 2–10 keV band, are associated with EROs. All of the X–ray detected EROs show rather extreme X–ray–...

LBQS 0103−2753 is a binary quasar with a separation of only 0.3 arcsec. The projected spacing of 2.3 kpc at the distance of the source (z = 0.848) is much smaller than that of any other known binary QSO. The binary nature is demonstrated by the very different spectra of the two components and the low probability of a chance pairing. LBQS 0103−2753 presumably is a galaxy merger with a small phys...

Since September 2005, the Whipple 10 m Gamma-ray Telescope has been used primarily to monitor known TeV AGN. The five Northern Hemisphere blazars that have been previously detected at Whipple, (Markarian 421, H1426+428, Markarian 501, 1ES 1959+650 and 1ES 2344+514) are monitored each night that they are visible. A number of multiwavelength observing campaigns have been undertaken by many collab...

We study matter effects on oscillations of high-energy neutrinos in the Universe. Substantial effect can be produced by scattering of the neutrinos from cosmological sources (z > ∼ 1) on the relic neutrino background, provided that the latter has large CP-asymmetry: η ≡ (n ν − n ¯ ν)/n γ > ∼ 1, where n ν , n ¯ ν and n γ are the concentrations of neutrinos, antineutrinos and photons. We consider...