Redshifts of one million galaxies selected from SDSS imaging data will be used to map the large scale structure of the nearby universe. Spectra will be observed with two dual-channel fiber optic spectrographs on the SDSS 2.5 m telescope. Each spectrograph accepts 320 f/4 beams from fibers positioned on an aluminum plate at the telescope focal plane. Light from the fibers is presented to a spherically figured collimator mirror, then split at 6000 Angstroms by a dichroic beamsplitter and presented to two large grisms. After dispersion by the grisms, two 8-element cameras image the spectra onto two 2048x2048 CCD detectors. This system records 640 spectra with a uninterrupted wavelength coverage from about 3900 to 9100 Angstroms at a resolving power of about R=1800.
American Astronomical Society Meeting Abstracts
- Pub Date:
- December 1999