| Description |
There is much controversy concerning the ionized nebula that produces
the radio through FIR emission from symbiotic stars. The goal of the
proposed Herschel observations is to test two popular models for this
emission; whether it is produced by a wind from the red giant that is
photoionized by Lyman continuum photons from the hot WD (STB) or it
comes from plasma that is shock heated as the winds from the two stars
collide by constraining the submm SED and measuring the free-free
turnover frequency of the ionised component. These two models predict
distinctly different shapes for the submm portion of the SED and
different dependence of the turnover frequency on binary separation.
Thus, submm photometry of a diverse sample of symbiotic stars with
know binary parameters that only Herschel can perform is an ideal way
to quantitatively test and discriminate between these models (as well
as motivate new ones). In terms of astrophysical significance,
determining the origin of the radio-through-FIR emission from
symbiotic stars has implications for the nature and geometry of mass
transfer in wide binaries, mass loss from accreting compact objects,
the shaping of asymmetric nebulae around binary stars (including
binary planetary nebulae), and the likelihood that symbiotic stars can
explode as type Ia supernovae. |
