2.3 High-z: The New Frontier
Perhaps one of the most exciting developments in recent years has been the discovery of a population of luminous, star-forming galaxies at z ~ 3, using a color criteria sensitive to the presence of the Lyman continuum break (Steidel & Hamilton 1993). Currently, the spatial distribution of these Lyman break (U-dropout) objects is being investigated and spectroscopic redshifts have been obtained for about 500 galaxies (Steidel, this proceedings). Preliminary results have led to the discovery of a large structure at z ~ 3.1, which could indicate that well developed, large-scale structures exist at even these high redshifts (Steidel et al. 1998).
Another important development is the construction of near-IR spectrographs (e.g., NIRMOS-VLT) to measure galaxy redshifts in the interval 1 < z < 3, where most of the spectral features lie outside the optical window. This will allow to bridge the gap that currently exists between the low-z (z 1) and high-z (z 3) domains.
Figure 2. A comparison of recent measurements of the local LF divided by morphological type. Solid lines and open squares represent the SSRS2; dashed lines represent the CfA Survey and dotted lines represent the Stromlo-APM (for details see Marzke et al. 1998).