Annu. Rev. Astron. Astrophys. 2000. 38: 667-715 Copyright © 2000 by Annual Reviews. All rights reserved

6. CONCLUSION

The HDFs represent an important portion of the frontier in studies of the distant universe. Although we can point to few problems that were solved by the HDF alone, the HDF has contributed in a wide variety of ways to our current understanding of distant galaxies and to shaping the debate over issues such as the origin of elliptical galaxies and the importance of obscured star formation. The scientific impact of the HDF can be attributed in part to the wide and nearly immediate access to the data. The fact that many groups and observatories followed this precedent (both for HDF data and subsequently for data from other surveys) illustrates that the deeper understanding of the universe will come not from any one set of observations but from sharing and comparing different sets of observations. Not all kinds of surveys are amenable to this kind of shared effort, but the precedent set by the HDF in the social aspects of carrying out astronomical research may ultimately rival its significance in other areas.

Acknowledgments

We are indebted to our fellow HDF enthusiasts, too numerous to mention, for the many fruitful discussions that have provided input for this review. The observations themselves would not have happened without the dedicated contribution from the HST planning operations staff, to whom we owe the largest debt of gratitude. This work was based in part on obsevations with the NASA/ESA Hubble Space Telescope obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. This work was partially supported by NASA grants GO-07817.01-96A and AR-08368.01-97A.