Paper: astro-ph/0511223
Date: Tue, 8 Nov 2005 15:23:50 GMT (297kb)

Title: Performance study of ground-based infrared Bracewell interferometers -
Application to the detection of exozodiacal dust disks with GENIE

Authors: O. Absil, R. den Hartog, P. Gondoin, P. Fabry, R. Wilhelm, P. Gitton,
and F. Puech

Comments: A&A, accepted
\\
Nulling interferometry, a powerful technique for high-resolution imaging of
the close neighbourhood of bright astrophysical objets, is currently considered
for future space missions such as Darwin or the Terrestrial Planet Finder
Interferometer (TPF-I), both aiming at Earth-like planet detection and
characterization. Ground-based nulling interferometers are being studied for
both technology demonstration and scientific preparation of the Darwin/TPF-I
missions through a systematic survey of circumstellar dust disks around nearby
stars. In this paper, we investigate the influence of atmospheric turbulence on
the performance of ground-based nulling instruments, and deduce the major
design guidelines for such instruments. End-to-end numerical simulations allow
us to estimate the performance of the main subsystems and thereby the actual
sensitivity of the nuller to faint exozodiacal disks. Particular attention is
also given to the important question of stellar leakage calibration. This study
is illustrated in the context of GENIE, the Ground-based European Nulling
Interferometer Experiment, to be installed at the VLTI and working in the L'
band. We estimate that this instrument will detect exozodiacal clouds as faint
as about 50 times the Solar zodiacal cloud, thereby placing strong constraints
on the acceptable targets for Darwin/TPF-I.

\\ ( http://arXiv.org/abs/astro-ph/0511223 , 297kb)