Survey Summary

The Extended Baryon Oscillation Spectroscopic Survey is a cosmological spectroscopic survey of millions of galaxies and quasars probing the large-scale structure of the Universe.  eBOSS is an extension of the SDSS-III BOSS survey, which ran from 2008-2014.  eBOSS continued collecting data between 2014-2020 as part of the SDSS-IV project.  The final data release of eBOSS (DR17) includes reductions of all observations taken by eBOSS in SDSS-IV as well as BOSS in SDSS-III.  All observations have been processed with the same eBOSS Data Reduction Pipeline.  Figure 1 shows a graphical overview of the eBOSS survey, demonstrating how high-redshift quasars are bused to map the large scale structure of the Universe.

Telescopes & Instrumentation

eBOSS data were obtained at the Apache Point Observatory in New Mexico using the SDSS-2.5m telescope (Gunn et al. 2006), using the BOSS spectrograph.  The BOSS spectrograph is a ``1000 fiber-fed spectrograph with wavelength coverage between 360 nm to 1040 nm and resolution (λ/δλ) of roughly 2000.   SDSS observed using plug plates, aluminum plates with holes drilled corresponding to individual astronomical objects or random blank areas of sky.  A plug plate covers a 3-degree diameter circle on the sky, with each fiber having a 2-arcsec diameter.  Each of the 1000 fibers were plugged into individual holes for each plate for an observation, allowing for 1000 spectra to be taken simultaneously. A picture of a plate used in the eBOSS survey is shown in Figure 2.