Near-IR Spectroscopy of High-z QSOs: Relating the Broad and Narrow-Line Regions

Abstract

Recent investigations of the broad UV lines in luminous QSOs identified strong correlations involving emission-line widths, shifts, equivalent widths, and ratios (Francis et al. 1992; Wills et al. 1993; Brotherton et al. 1994a, b). A simple model developed to explain these trends approximates UV broad lines as emission from two regions, an intermediate-line region (ILR), and a very broad-line region (VBLR), together comprising the traditional broad-line region (BLR). The observed and derived properties for the ILR and VBLR are summarized in Table 1, along with typical values for the narrow-line region (NLR).