Quasar Properties from the Sloan Digital Sky Survey. III. The Quasars Obtained by the SDSS-IV

Abstract

Abstract This paper provides the compilations of properties of the quasars newly obtained by the Sloan Digital Sky Survey (SDSS) during the fourth stage (SDSS-IV). The catalog is available on the journal's website. We have measured the main properties of emission lines around C iv, Mg ii, Hβ, and Hα spectral regions. We estimate the quasar redshifts from our fits of narrow [O iii], broad Mg ii, and broad C iv emission lines and find that the best redshifts included in DR16Q are robust with respect to our measurements. Based on the broad C iv, Mg ii, Hβ, and/or Hα emission lines, we calculate the virial black hole mass with empirical relationships provided by previous works. Systematic biases are found among the different line-based mass estimators.