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Paper: How Much of the Broad-Line Region is Outflowing ?
Volume: 255, Mass Outflow in Active Galactic Nuclei: New Perspectives
Page: 261
Authors: Gaskell, C. M.; Mariupolskaya, V. Y.
Abstract: The blueshifting of the high-ionization broad emission lines in AGNs is probably caused by outflow of high-ionization gas coupled with obscuration by a disk but there has been no consensus on the overall kinematics of the BLR gas and the relationship of the low-ionization BLR gas to the high-ionization BLR gas. We have studied the widths of high- and low-ionization emission lines in Hubble Space Telescope, IU, and ground-based spectra. We confirm that there is considerable scatter between the CIV and Mg II FWHMs, but nonetheless there is a highly-significant correlation and the profiles can be identical. The widths of these lines and Hbeta are correlated over the full range of widths from Narrow-Line Seyfert 1s (NLS1s) to Broad-Line Radio Galaxies (BLRGs). The correlations imply that the kinematics of the high and low-ionization gas are related, and support an underlying unity among the different classes of AGN. A significant part of the low-ionization BLR gas is thus probably outflowing with the high-ionization BLR. One problem any theory of BLR structure and kinematics must explain, however, is the absence of lags between the blue and red wings of lines as they vary.
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