Galaxies, Quasars and Cosmology

The following sections are included:

• PREFACE

• CONTENTS

Recent developments in the study of the three-dimensional shapes of elliptical and disk galaxies are reviewed.

The observations that the rotation curves of some spiral galaxies are flat in regions extending from R ~ 10 Kpc all the way up to ~ 50-100 Kpc (Bosma, 1978; Rubin et a1. 1982, and Burstein et al. 1982) is the single most important evidence either for the existence of massive galactic halos of dark matter (on the non-Barionic nature of this matter see e.g. Hegyi et at. 1983), or for a breakdown at a classical level of the laws of dynamics and gravitation (Mi1grom, 1983, and references therein). We assume in the following that the general relativity postulates are valid, and we infer from the constancy of the rotation curves, properties of the “dark” matter component of the galactic halos. In the absence of observational counter-examples, and for the sake of simplicity, we assume the halos have a zero total angular momentum and spherically symmetric density distribution…

It is well known that a galaxy is composed of a large number of stellar components each characterized by its own velocity field and in equilibrium with their average gravitational field. In order to arrive at a detailed astrophysical description of a galaxy we cannot forego the knowledge of these components, of their relative abundances, or of their phase space distributions. Nevertheless, due to the complexity of the problem [1], it is worthwhile trying to formulate a model with drastic simplifying assumptions which lends itself to an analytic treatment and reproduces some of the most relevant features of galactic structure. One can first try to describe the structure of a galaxy as a simple distribution of matter with a constant “effective density”, an “isotropic pressure”, and a constant “effective angular velocity”. This treatment, following the classical works on the ellipsoidal figures of equilibrium, leads unequivocally to the conclusions that our own galaxy should be unstable towards the formation of bar-like structures [2]…

Galactic globular clusters (and dwarf spheroidal galaxies) can be studied as isolated star systems, or as star systems orbiting the Galaxy. In both cases they give information on a large number of topics, including age, original chemical ccmposition, galactic structure and Galaxy evolution. These two aspects will be considered in the following, and some recent results will be reviewed. Star evolution provides data on age and chemical composition; stability analysis of globular clusters gives indications of the galactic structure.

The following sections are included:

• INTRODUCTION

• QUASAR-LIKE OBJECTS (AGNs)
  • Seyfert Galaxies
  • Quasars
  • BL Lac Objects
  • Radio Galaxies
  • Other AGNs

• SUPERMASSIVE BLACK HOLE MODELS
  • Rapid Large Amplitude Variabilities
  • Beams and Jets
  • Composite Models (Tentative)

• SPECTRA OF RADIATION FROM ACTIVE GALACTIC NUCLEI
  • X-Ray Spectra
  • Infrared-Optical-Ultraviolet Spectra

• SOME MODELS FOR EMISSION MECHANISMS

• DISCUSSION AND CONCLUDING REMARKS

• FOOTNOTES

• ACKNOWLEDGEMENTS

• REFERENCES

We describe a new method of investigating the features of the Cosmic Background Radiation, searching for its temporal fluctuations by means of a Infrared Correlator. We describe here the preliminary results of a balloon flight devoted to this measurement.

We describe the theoretical motivaions of a new, balloon borne experiment, devoted to the search for extragalactic background’s anisotropies, together with the experimental problems connected with it; we report the principal results of a preceeding balloon flight as a proof of the power of the method used.

The production of elementary particles in the big bang is discussed. In particular, the possibility that some elementary particle (“ino”) is produced in the big bang and is present today in sufficient numbers to contribute to the overall mass density of the Universe in the form of dark matter is illustrated with several examples. The production of neutrinos, axions and baryons are covered in detail.

The most important problem in cosmology is the birth of the universe. Recently Hartle and Hawking put forward a ground state proposal for the quantum state of the universe which incorporates the idea that the universe must come from nothing. Many models have been discussed in quantum cosmology with this boundary condition. It has been shown that every model is a step towards to a realistic universe, i.e. a 4-dimensional isotropic universe with a long inflationary stage.

The following sections are included:

• INTRODUCTION

• THE ACTION

• THE ENERGY MOMENTUM TENSOR AND THE FIELD EQUATIONS

• BUBBLE DYNAMICS

• APPENDIX

• REFERENCES

The discovery of sunspot phenomena in ancient China have been discussed from the view point of folklore and mythology. On the basis of naked-eye sunspot records the solar variability of two thousand years may be revealed. The dispute over the Maunder Minimum could lead to new understanding of the essence of solar activity and new-construction of solar dynamo theory.