The Completed Sloan Digital Sky Survey IV Extended Baryon Oscillation Spectroscopic Survey: The Damped Lyα Systems Catalog

Abstract

Abstract We present the characteristics of the damped Lyα (DLA) systems found in data release DR16 of the extended Baryon Oscillation Spectroscopic Survey of the Sloan Digital Sky Survey. The DLAs were identified using the convolutional neural network of Parks et al. (2018). A total of 117,458 absorber candidates were found with 2 ≤ z DLA ≤ 5.5 and 19.7 ≤ log ( N ( H I ) / cm − 2 ) ≤ 22 , including 57,136 DLA candidates with log ( N ( H I ) / cm − 2 ) ≥ 20.3 . Mock quasar spectra were used to estimate the DLA detection efficiency and the purity of the resulting catalog. Restricting the quasar sample to bright forests, i.e., those with mean forest fluxes f λ ¯ > 2 × 10 − 19 W m − 2 nm − 1 , the efficiency and purity are greater than 90% for DLAs with column densities in the range 20.1 ≤ log ( N ( H I ) / cm − 2 ) ≤ 22 .