Murray & Chiang (1997) developed a model wherein broad emission lines come from the optically thick base of a rotating, outwardly accelerating wind at the surface of an accretion disk. Photons preferentially escape radially in such a wind, explaining why broad emission lines are usually single-peaked. Less well understood are the observed shifts of emission-line peaks (from 1000 km s−1 redshifted to 2500 km s−1 blueshifted in C iv, with an average 800 km s−1 blueshift).

The spectra of the Sloan Digital Sky Survey (SDSS) are being used to construct a catalogue of QSO absorption lines, for use in studies of abundances, relevant radiation fields, number counts as a function of redshift, and other matters, including the evolution of these parameters. The catalogue includes intervening, associated, and BAL absorbers, in order to allow a clearer definition of the relationships between these three classes. We describe the motivation for and the data products of the project to build the SDSS QSO absorption line catalogue.

We are investigating field galaxy evolution with the optical multiband survey of Osmer et al. (1995, in preparation; Hall et al. 1992, Bull. A.A.S., 24, 1136), which covers some 3000 sq. arcmin of sky with CCD photometry in six broad-band filters from 3000-10000Å, complete down to R∼23. The sample contains some 9000 cataloged galaxies, of which 7000 have data in at least three colors.