The following document lists the file abstract/DHINES_HINE_IRQ.abs
from catalogue VI/111.
A plain copy of the file
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I propose to use the SWS with AOT SWS01 to obtain mid-infrared spectra of a subsample of Infrared-Ultraluminous Active Galactic Nuclei characterized by their "warm" far-infrared spectral energy distributions as obtained by IRAS. Fine structure emission line ratios (and the mere presence of the lines such as [NeV]) will be used to derive the ionization parameters, electron densities and ionizing continua in these often highly obscured objects. My ground-based optical spectropolarimetry indicates that ALL of these objects harbor a Broad Line Region seen in polarized light even if this the emission does not dominate the total optical spectrum. This suggests an axisymmetric geometry for these very luminous objects similar to that suggested for the lower luminosity Seyfert galaxies. Unfortunately, disentangling the geometry requires both a knowledge of the scatterers AND the input spectrum impinging on the scatterers. Mid infrared spectroscopy will allow observations of physical conditions very near the central engine and well within the scattering regions, which are themselves obscured from direct view in two objects. The input spectrum (inferred from the mid-infrared fine structure emission lines) combined with polarization information provides very important constraints on the geometry of these objects. ISO is the only instrument capable of providing continuous high signal-to-noise spectra of these objects.