Several groups have been successful in the survey of high-redshift (z > 4) quasars. For example, Schneider et al. (1994) and Schmidt et al. (1995) were successful in detecting 90 quasars with 2.75 < z < 4.75, R < 21 for 62deg2 using Palomar Transit Grism. Among them, there are 9 quasars with z > 4.0. Storrie-Lombardi et al. (1996) were detected 31 quasars with z > 4.0, mT < 19 for 2500deg2 by APM photographic multicolor survey using UK Schmidt telescope. Survey observations of quasars up to now have to select one of the following conditions; wide field surveys using photographic Schmidt plate which cover large areas but do not go faint enough, or deep surveys using large telescopes which go faint magnitude but which cover relatively small areas.

With the current convergence of determinations of the Hubble Constant (e.g. The Extragalactic Distance Scale, 1997, Livio, Donahue and Panagia, eds.) to values within ±25% rather than a factor of two, and the clear possibility of determining q0 using high redshift supernovae (Garnavich et al. 1998), the major remaining problem in observational cosmology is the determination of Ω — what is the dark matter, how much is there, and how is it distributed?

The most direct approach to the last two parts of the question has been to study galaxy dynamics, first through the motions of galaxies in binaries, groups and clusters, and in the last decade and a half, driven by the observation of our motion w.r.t. the Cosmic Microwave Background (CMB) and thenotion that DM must be clumped on larger scales than galaxy clusters if (Ω is to be unity, through the study of large scale galaxy flows.

The ratio of the mass density to the closure mass density, Ω, is thought by most observers to be ~0.1-0.3, primarily based on the results of dynamical measurements of galaxy clusters and, more recently, gravitational lensing studies of clusters. In contrast, most theoretical cosmologists opt for a high density universe, Ω = 1.0, based on the precepts of the inflation scenario, the difficulty of forming galaxies in low density models given the observed smoothness of the microwave background radiation, and the observational evidence from the matching of the available large scale flow measurements (and the absolute microwave background dipole velocity) to the local density field. However this last result is extremely controversial—matching the velocity field to the density field derived from IRAS (60μ) selected galaxy samples yields high Ω values (e.g., Dekel et al. 1993) but matching to optically selected samples yields low values (Hudson 1994; Lahav et al. 1994; Santiago et al. 1995). On small scales, the high Ω camp argues that the true matter distribution is much more extended than the distribution of galaxies, so the dynamical mass estimates are biased low.

Large and deep spectroscopic samples of galaxies are essential to study galaxies and large scale structure evolution out to look-back times ~ 10% the current age of the vmiverse. Keeping this scientific and observational goal in mind, we designed and are presently building two wide-field imaging spectrographs to be installed at the Nasmyth foci of the ESO-VLT Unit Telescopes 3 and 4.

In China, we will start to build a new spectroscopic survey telescope. It will be a meridian reflecting Schmidt telescope. The optical system is horizontal. The primary mirror is spherical and segmented. It faces towards the north. In its spherical center there is a plane mirror which is segmented too. The different shape of reflecting Schmidt plate is realized by active optics. The clear aperture is 4 m and f-ratio is 5. The angular field of view is 5 square degree, 4000 objects can be observed simultaneously by using optical fibre. The science goal is to make a 20000 square degrees spectroscopic survey, including ten million galaxies and stars, many variable objects and the identification of numerous objects found by radio, x-ray, IR and other survey in these sky areas.

Electronic publishing of journals has already arrived, and is established. The Astrophysical Journal and Letters, Astronomy and Astrophysics Supplements and New Astronomy have been publishing a parallel electronic edition since the beginning of 1997. Astronomy and Astrophysics will follow in 1998, and the Monthly Notices of the Royal Astronomical Society are being developed. The American Astronomical Society has been the leader in developing electronic publishing in astrophysics. They have led not only by being first, but also by the high standards of their electronic publication.

One of the stories that school children in Great Britain learn at an early age is about King Canute II. Canute was a Danish king who ruled part of what is now Great Britain from 1016 to 1035. He is famous because he sat bythe sea as the tide was coming in and commanded the tide to go back. It didnot.

Electronic publication is going to bring many changes to the way research is done and published. There are obvious advantages and disadvantages. There are certainly problems which we have not yet realized. The purpose of this Joint Discussion is to stimulate a discussion of what the international astrophysical community would like from electronic publishing. Please do not say that you want electronic publishing to go away, because then you will be behaving like King Canute. But the publishers of journals and the bodies responsible for maintaining the quality of publication are feeling their way into completely new territory. To exploit electronic publishing to the full, and to minimize the disadvantages, discussion in the community is needed.

Electronic publishing will bring great connectivity into journals. While looking at one paper, a click on the mouse will immediately connect with another paper published in another journal. Large tables, theoretical or observational, will be read in the same way from databases. An electronic publication will longer be static. It can be modified to refer to papers published later, it can contain movies or computer programs that can be executed online.

Links are important. The providers of electronic astronomical data are linked together the way no other science is. Electronic journals are part of this distributed, linked resource. Permanence is important. The AAS journals use a new publishing process which ensures the ability to maintain permanent access to our electronic journals. Process is important. With the right process, we have been able to add links automatically to our journal; links to references, links to citations (where the electronic material exists) and internal links for ease of navigation within the journal. Readers like this. Links are important.

Archiving electronic journals is complex. There are many questions; Who archives? What is archived? How many copies should be archived. How can one ensure the integrity of electronic documents? How can access be maintained? Technology will provide some answers. Electronic archives will require periodic refreshing and migration to new technology. Many factors remain unknown at this time.

Paper preprints are in decline in astronomy, while the use of electronic preprints is on the rise, mainly via the LANL astroph preprint archive. I discuss the decline of the paper preprint, some preprint servers available on the Web and some general electronic preprint issues, the astropharchive and its response to these issues, and alternatives for the future of electronic preprints.

The Astrophysics Data System (ADS) is an integral part of the Astronomy Digital Library and the collaboration Urania. It provides access to 1 million references and connects these references with many other information centers and their data, such as on-line journals, object databases, and scanned journal articles. This article describes some of the features and links between the ADS and other on-line services.

The Centre de Données astronomiques de Strasbourg (CDS) has dealt with bibliographic information for many years. References of publications, published observational data related to objects, data tables, nomenclature, have been homogenized and organized into information retrieval systems: SIMBAD, the reference database for the identification and bibliography of astronomical objects; the catalogue service and the VizieR catalogue Browser, for data tables; the Dictionary of Nomenclature of Astronomical objects, which is now maintained by the CDS. Evolution in recent years has brought the Data Centers closer to the publishing process. General standards for astronomy, for the description of references and of data tables, have been proposed and implemented. Data tables from papers are now directly published in electronic form, and distributed on-line by the Data Centers. The emergence of fully electronic publication paves the way to innovative new services, linking the journals to other sources of informations (data bases, tables, then images, data archives), and making use of new methods for information retrieval. This also has an effect on the publishing process, with the possibility to implement new checks and links from text to other kinds of information (from objects names, positions, etc.). The CDS will bring some of thekey features in the evolution towards a fully linked astronomy information system, in close collaboration with the journal editors, the ADS, the other Data Centers, and the data providers.

The developing countries at the low end of the scale face almost insurmountable problems in accessing electronic information. In Nigeria, only two of 40 universities have e-mail. Although electronic access to current information could revoutionize the educational situation at these places, the communication infrastructure does not exist, nor does the necessary funding.

The astrometric results of Hipparcos include the positions at epoch (1991.25), the proper motion in the new IAU extragalactic reference system (ICRS), and parallaxes for about 118 000 stars. One dimensional positions are also given for 48 asteroids and 3 satellites. Due to the non-isotropy of the scanning law, the uncertainties are position dependent. Some indications of the remaining correlations are given. Various tests and comparisons show that systematic errors in parallax, if any, are not larger than 0.1 millisecond of arc.

The Hipparcos Catalogue provides general astrometric and photometric information on double and multiple stars in specific fields of the main Catalogue and detailed data on the components in the various sections of a dedicated annex: the Double and Multiple Systems Annex (DMSA). Overall statistics of these solutions are presented for the 13211 entries of this annex and the different types of solutions are outlined.

During the development of the Hipparcos satellite, the opportunity to use the star mapper to perform a whole sky two colour intermediate accuracy photometric survey, and the main-mission detector for high accuracy photometry of target stars was identified. The instrument was optimised and the pre-launch calibrations performed to pre-determine the pass-bands with an accuracy sufficient to cope, in-orbit, with the foreseen aging of the detection chains. Photometry became an important by-product of the mission, very complementary to the astrometric results. It was the first opportunity to monitor the sky during 3-4 years without selection biases and with a precision similar to that achieved from the ground with the best classical techniques. A systematic detection of small amplitude variables was the expected return.

The Tycho Catalogue contains basic astrometric and photometric data for a million stars on the sky, complete to about V = 10.5 mag. The accuracy at the catalogue epoch (J1991.25) of positions and two-colour magnitudes is generally an order of magnitude better than has hitherto been available for the majority of these stars. Results from the production and verification of the catalogue is presented. The catalogue and associated epoch photometry annex are available in machine-readable form as part of the final Hipparcos mission products.

This contribution is intended as a ‘rough guide’ to the Hipparcos Catalogue for the non-expert user. We shall focus here on the interpretation of the measured parallaxes in terms of distances and luminosities of stars, and on the use of the covariance matrix of the errors on the astrometric parameters. Issues not addressed here are the level at which one may expect systematic errors to occur in the Hipparcos Catalogue, and the correlation of astrometric parameters over a given region of the sky. For more details on the latter two subjects we refer to the documentation of the Hipparcos Catalogue (ESA, 1997) and to Brown et al. (1997). We note that at present the Hipparcos Catalogue contains no identified systematic errors.