Indecent Exposure in Seyfert 2 Galaxies: A Close Look
  NGC 3147, NGC 4698 and 1ES 1927+654 are active galaxies that are classified
as Seyfert 2s, based on the line ratios of strong narrow emission lines in
their optical spectra. However, they exhibit rapid X-ray spectral variability
and/or little indication of obscuration in X-ray spectral fitting, contrary to
expectation from the active galactic nucleus (AGN) unification model. Using
optical spectropolarimetry with LRIS and near-infrared spectroscopy with
NIRSPEC at the W. M. Keck Observatory, we conducted a deep search for hidden
polarized broad H-alpha and direct broad Pa-beta or Br-gamma emission lines in
these objects. We found no evidence for any broad emission lines from the
active nucleus of these galaxies, suggesting that they are unobscured,
completely "naked" AGNs that intrinsically lack broad-line regions.
