Near-Infrared Imaging Polarimetry of Embedded Young Stars in the Taurus-Auriga Molecular

WHITNEY, B. A.., KENYON, S. J., GOMEZ, M.

IOP PUBLISHING LTD

Lugar: Londres; Año: 1997 p. 703 - 703

e describe near-infrared (JHK) imaging polarimetry of 21 embedded protostars in the Taurus-Auriga molecular cloud. These objects display extended, highly polarized reflection nebulae with V-shaped, unipolar, and bipolar morphologies. Most sources have PK ~ 5%-20% in an 8" aperture; a few objects have PK <~ 5%. The polarization increases toward shorter wavelengths and is generally aligned perpendicular to the long axis of the reflection nebula. We develop an analytic scattering model for the near-IR colors and polarizations of embedded protostars. Our Taurus data require visual extinctions, AV ~ 25-60 mag, comparable to those predicted for models of collapsing clouds. The ratio of scattered flux to intrinsic source flux ranges from Fs/F0 ~ 0.001 at 1.25 mu m to Fs/F0 ~ 0.015 at 3.5 mu m. These results indicate that the observed ratio of scattered light to direct (extincted) light increases from Fs/Fd ~ 0.1 at 3.5 mu m to Fs/Fd ~ 25 at 1.25 micron. Our data further requ