Publications
of the
MPIfR
Optical & Infrared
Interferometry Group
T. Blöcker, K.-H. Hofmann, F.
Przygodda, and G. Weigelt:
The VLT Interferometer and its AMBER
Instrument:
Simulations of Interferometric Imaging in the Wide-Field Mode
Astronomische Gesellschaft Meeting Abstracts (AGM 17,
P18), Dynamic Stabilitiy and Instabilities in the Universe
Annual Scientific Meeting of the Astronomische Gesellschaft, Sep 18-23,
2000, Bremen, Germany
Abstract.
We present computer simulations of interferometric imaging with the VLT
interferometer and the AMBER instrument. These simulations include both
the
astrophysical modelling of a stellar object by radiative
transfer calculations and the simulation of light propagation from the
object
to the detector (through atmosphere, telescopes, and the AMBER
instrument),
simulation of photon noise and detector read-out
noise, and finally data processing of the interferograms. The results
show the dependence of the visibility error bars on the following
observational parameters: different seeing during the observation of
object
and reference star (Fried parameters r_object and r_ref. ranging
between
0.9 m and 1.2 m), different residual tip-tilt error
(delta_object and delta_ref. ranging between 0.1% and 20% of the Airy
disk diameter), and object brightness (Kobject=3.5 mag to 13 mag,
Kref.=3.5 mag).
Exemplarily, we focus on stars in late stages of stellar evolution and
study
one of its key objects, the dusty supergiant IRC +10 420 that is
rapidly
evolving on human timescales. We show computer
simulations of VLT interferometry of IRC +10 420 with two ATs
(wide-field
mode, i.e. without fiber optics spatial filters) and discuss whether
the
visibility accuracy is sufficient to distinguish between
different theoretical model predictions.