Accurate galactic N(H) values towards quasars and AGN

摘要: Integrated Galactic 21-cm column densities toward about 174 quasars and AGN are presented. The data corrected for stray radiation, using the technique of Lockman et al. (1986). Because 21-arcmin beam size 140-ft telescope used in study, uncertainty N(H) due to angular variations H I Galaxy at high latitudes is minimized. accurate 1 X 10 19th atoms/sq cm, or 5 percent, whichever larger. Errors above 4 20th cm dominated by opacity uncertainties. 24 references.