Monday 17 September at 2pm
Sebastian Wolf - Thuringer Landessternwarte Tautenburg
"Alignment of Disks of TTauri Binary Stars"
ABSTRACT: "I will present the results of a study performed with the
goal to investigate whether low-mass pre-main sequence binary stars are
formed by multiple fragmentation or via stellar capture. If binaries form
preferentially by fragmentation, their disks are expected to be co-planar.
On the other hand, the capture scenario will lead to a random distribution
of disk orientations. For this reason, near-infrared polarization measurements
of 49 young close binary stars in the K band with SOFI at the NTT have
been performed. The near-infrared excess radiation of the targets mostly
point to the presence of disks. For a major fraction of the sample, evidence
for disks is also obvious from other features (outflows, jets, Herbig-Haro
objects). The disk orientation was derived from the orientation of the
polarization vector of both components of each binary. This statistical
study allows to test which hypothesis (co-planarity, random orientation)
is consistent with the observed distribution of polarimetric position angles.
Evidence was found that the disks are preferentially aligned."
|
