Scattered Light and Polarized Light in Models of KH 15D
Eric B. Ford, Jennifer
L. Hoffman, and Eugene
I. Chiang |
| Recent analyses have suggested that the peculiar eclipses of
the pre-main sequence binary star KH 15D result from occultation of the
visible stellar companion by the edge of an opaque scattering screen,
likely the projection of a circumbinary disk. We present the results of
single- and multiple-scattering radiative transfer models of this
system. Our simulations place upper limits on the mid-eclipse
brightness as functions of the warp amplitude, inner radius, and albedo
of an optically thick circumbinary disk; these limits suggest that the
light scattered by such a disk is not sufficient to explain the
observed brightness of KH 15D at mid-eclipse. A secondary scattering
region (such as a jet, outer disk or halo, or stellar corona) may
provide the observed light during eclipse. The occulting disk may also
emit light whose contribution becomes significant when both stars are
eclipsed. We calculate the flux and polarization contributions of these
scenarios, and investigate their effects on the mid-eclipse brightness
and polarization of the system. E.B. Ford is supported by the Miller Institute for Basic Research at UC Berkeley. J.L. Hoffman is supported by an NSF Astronomy & Astrophysics Postdoctoral Fellowship under award AST-0302123. |
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For more information, please send email to Jennifer. January 20, 2005 |