Two Highly Polarized Quasi-stellar Objects Discovered by the Two Micron All Sky Survey

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Abstract
We present optical observations of two remarkable new active galactic nuclei (AGNs) discovered by the Two Micron All Sky Survey. Both are classified as quasi-stellar objects (QSOs) based on their optical spectra, near-IR colors, and near-IR and [O III] λ5007 luminosities, but their optical polarizations are among the highest seen for nonblazar AGNs—approaching 15% for 2MASSI J151653.2+190048. The polarized light spectrum for each object exhibits broad Balmer emission lines but lacks the narrow lines that are evident in the total light spectrum. This is most pronounced for the type 1.5 object 2MASSI J165939.7+183436, where broad lines dominate only in polarized light. The polarization properties of these AGNs suggest that dust near the nucleus at least partially obscures the AGNs and that material probably intermixed with the narrow-line-emitting gas scatters nuclear light into our line of sight. These QSOs illustrate the variety of highly polarized AGNs that have been missed by traditional optical search techniques and demonstrate that such objects are exposed by surveys in the near-IR.