To constrain the origin of scaling relations between black hole mass and galaxy properties, i.e., stellar velocity dispersion and bulge luminosity, we investigate the evolution of scaling relations in the past 6 Gyrs. Over the last three years, we have obtained high signal-to-noise ratio Keck spectra of ~ 50 intermediate luminosity broad-line AGNs at z ~ 0.4 and z ~ 0.6, to measure stellar velocity dispersion, and HST (ACS and NICMOS) images of the same objects (~ 40 so far), to measure bulge luminosity from the two-dimensional AGN-galaxy decomposition analysis. In this paper, we will summarize the main results on the MBH–σ and MBH–bulge luminosity relations and their evolution to the present-day universe. The measured scaling relations show that the relations have evolved significantly in the past 6 billion years, and that black hole growth predates the final galaxy assembly.

Recent numerical investigations have focused attention once more on the role of intermediate shocks in MHD. Four types of intermediate shock are identified using a graphical representation of the MHD Rankine-Hugoniot conditions. This same representation can be used to exhibit the close relationship of intermediate shocks to switch-on shocks and rotational discontinuities. The conditions under which intermediate discontinuities can be found are elucidated. The variations in velocity, pressure, entropy and magnetic-field jumps with upstream parameters in intermediate shocks are exhibited graphically. The evolutionary arguments traditionally advanced against intermediate shocks may fail because the equations of classical MHD are not strictly hyperbolic.

Strongly correlated non-intrinsic variability between 5 and 8.5 GHz has been observed in one of the lensed images of the gravitational lens B1600+434. These non-intrinsic (i.e. ‘external’) variations are interpreted as radio-micro-lensing of relativistic μas-scale jet components in the source at a redshift of z=1.59 by massive compact objects in the halo of the edge-on disk lens galaxy at z=0.41. We shortly summarize these observations and discuss several new observational and theoretical programs to investigate this new phenomenon in more detail.

A brief summary of some highlights in the study of high energy astrophysical sources over the past decade is presented. It is argued that the great progress that has been made derives largely from the application of new technology to observation throughout all of the electromagnetic and other spectra and that, on this basis, the next decade should be even more exciting. However, it is imperative to observe cosmic sources throughout these spectra in order to obtain a full understanding of their properties. In addition, it is necessary to learn the universal laws that govern the macroscopic and the microscopic behavior of cosmic plasma over a great range of physical conditions by combining observations of different classes of source. These two injunctions are illustrated by discussions of cosmology, hot gas, supernova remnants and explosions, neutron stars, black holes and ultrarelativistic outflows. New interpreations of the acceleration of Galactic cosmic rays, the cooling of hot gas in rich clusters and the nature of ultrarelativistic outflows are outlined. The new frontiers of VHE γ-ray astronomy, low frequency radio astronomy, neutrino astronomy, UHE cosmic ray physics and gravitational wave astronomy are especially promising.

Relativistic plasma masers operating on the anomalous cyclotron-Cherenkov resonance (ω - k||v|| + ωB/γres = 0) and on the Cherenkovdrift resonance (ω - k||v|| - kxud = 0) are capable of explaining the main observational characteristics of pulsar radio emission. Both electromagnetic instabilities are due to the interaction of the fast particles of the primary beam and from the tail of the distribution with the normal modes of a strongly magnetized, one-dimensional electron-positron plasma. In a typical pulsar, both resonances occur in the outer parts of the magnetosphere at rres ≍ 109 cm.

The Hubble Deep Field, henceforth HDF, (Williams et al 1996) is a unique data set for studies of faint galaxies. A small area was chosen well away from known local density enhancements and sources of obscuration. It was imaged for 30 complete orbits in each of four filters centered on wavelengths λ300, 450, 606, 814 nm. There are three, contiguous WFPC2 frames and a solid angle 15,500 arcsec2 is usable. This tiny region is teeming with galaxies. At least 2500 significant features can be identified down to R = 30, though it is not clear that these are all entire galaxies.

I have been asked to provide some general introduction to the topic of jets and high energy transients. I have chosen to do this by asking seven questions that seem to be timely following recent observational and theoretical developments, the most important of which may be the growing realization that the extragalactic- massive black hole and Galactic-stellar mass black hole manifestations of these phenomena provide two complementary ways of viewing a common physical mechanism. I have also chosen to illustrate these questions using one specific source in each case. The page limits prevent me from giving the answers. They also prohibit my even attempting to give a skeletal bibliography over so large a field. Fortunately almost all of these topics will be covered in greater depth during this meeting.

We present results on the promising new gravitational lens system 1608+656.

Recent observations have strengthened the dynamical arguments for the presence of black holes in X-ray binary systems, the Galactic center and the nuclei of the majority of bright galaxies. They have also drawn attention to the fact that accretion does not always proceed in the simple, stationary manner envisaged in early theories. I wish to discuss four related topics that are relevant to understanding the behavior of accreting black holes. (In view of the length constraints imposed by conference proceedings I shall make no attempt to give adequate bibliographic references for what follows.)

The discovery of megamasers in nearby active galactic nuclei (AGN) is an unexpected boon for AGN researchers. The most immediate benefit, brought out in observations of NGC4258 (Miyoshi et al 1995, Moran, these proceedings) is that it allows an accurate mass measurement for the central black hole, in this case of 3.6 x 107 M⊙, with unprecedented accuracy. (I shall not belabor the point that we have not proven rigorously that it is a black hole because this is surely on much firmer footing than what follows!) Masers also allow us to discover second order features of the kinematics, specifically that the disk is warped. Thirdly, and this is what I have been asked to review here, it should enable us to choose between several possible accretion modes by treating masers as diagnostic probes of physical conditions in the disk.

Some ways in which gravitational lenses can act as crude telescopes are reviewed. Magnification limits associated with finite source size, corrugation of the gravitational potential and finite wavelength are specified. It should be possible to obtain rotation curves for a small sample of ultra-faint galaxies imaged as giant arcs. There is an appreciable chance of eventually observing a radio jet component cross a caustic. The successful observation of microlensing in 2237+031 suggests that the continuum emission from this source at blue wavelengths is at least partly non-thermal. The maximum possible magnification observable, granted existing constraints is argued to be from γ-ray pulsars crossing caustic sheets formed by galaxies or a hypothetical population of intergalactic massive objects.

High-energy particle acceleration is observed to proceed in a diverse variety of astrophysical sites ranging from the terrestrial aurorae to the most distant quasars. Particle acceleration is a fairly common channel for the release of large-scale kinetic, rotational, and magnetic energy. Physical mechanisms include electrostatic acceleration, stochastic processes and diffusive shock energization. Cosmic-ray energy spectra have shapes which reflect escape, collisional, and radiative losses. The overall acceleration efficiency is controlled by the low-energy particle injection which may, in turn, feed back into the energization. Recent observational developments, which illustrate these general principles and raise fresh questions, are briefly summarized.

Subject heading: acceleration of particles

A conference devoted to the center of our Galaxy inevitably draws together astronomers from many different tribes speaking in tongues about what they each know to be truly important. We have heard from stellar dynamicists and users of magnificent infra-red arrays, (who are apparently only here by courtesy of a hole in the dust distribution), from molecular radio astronomers and experts on solar MHD, cosmic ray physicists and those who misguidedly believe that understanding the Galactic center is much easier than solving the mysteries of quasars. The Galactic center can lay claim to being the melting pot of astronomy and so it is quite appropriate that this conference should be held here in Southern California.

The observed evolutionary behavior of active galactic nuclei is compatible with a model in which black holes form in the nuclei of new-born galaxies and then grow at a rate limited by both radiation pressure and the supply of gas. Individual sources become more luminous with time as long as they are being fueled. However, the rapid decrease in the mean rate of supply of gas causes a strong decline in the space density of active objects. Nearby galaxies should harbor modest size (∼ 106 – 108 M⊙) black holes. It is suggested that the gas that fuels high redshift quasars is mostly derived from the host galaxy.

Observations of active galactic nuclei are interpreted in terms of a theoretical model involving accretion onto a massive black hole. Optical quasars and Seyfert galaxies are associated with holes accreting near the Eddington rate and radio galaxies with sub-critical accretion. It is argued that magnetic fields are largely responsible for extracting energy and angular momentum from black holes and disks. Recent studies of electron-positron pair plasmas and their possible role in establishing the emergent X-ray spectrum are reviewed. The main evolutionary properties of active galactic nuclei can be interpreted in terms of a simple model in which black holes accrete gas at a rate dictated by the rate of gas supply which decreases with cosmic time. It may be worth searching for eclipsing binary black holes in lower power Seyferts.

We summarize the discussion of the current status and future prospects of space and astrophysical plasma research prepared by the Panel on Space and Astrophysical plasmas, a part of the study on Physics administered by the National Research Council of the National Academy of Sciences. The Study on Physics is chaired by W. Brinkman of Bell Laboratories and will be completed in 1984.

We review attempts to incorporate radio sources within the context of general models of active galactic nuclei. The behaviour of gas accreting onto a massive black hole depends upon its angular momentum and accretion rate. It is argued that radio galaxies, QSR's and QSO's (and Seyfert 1 galaxies) be associated with increasing mass accretion rates The classification of an active galaxy appears to be aspect-dependent. In particular BL Lac objects, OVV quasars and the superluminally expanding compact sources appear to be beamed towards us. We show how the choice of source model can influence the statistics of beaming.

The nature, dynamics and evolution of the three known radio pulsar binaries are discussed. The system containing 1913+16 appears to comprise two ~1.4 M⊙ components, and to undergo orbital decay as predicted by general relativity. It is proposed that 1913+16 has a neutron star companion and that 0655+64 and 0820+02 have white dwarf companions which should be observable optically.