A scene model of exosolar systems for use in planetary detection and characterisation simulations^*

¹ Laboratoire Universitaire d'Astrophysique (LUAN), Université de Nice-Sophia Antipolis and CNRS (UMR 6525), Parc Valrose 06100 Nice, France e-mail: belu@unice.fr
² Université de Lyon, 69000 Lyon, Université Lyon 1, 69622 Villeurbanne, Centre de Recherche Astronomique de Lyon, Observatoire de Lyon, 9 avenue Charles André, 69561 Saint-Genis Laval Cedex, CNRS/UMR-5574, École Normale Supérieure de Lyon, Lyon, France
³ Institut d'Astrophysique Spatiale (IAS), bâtiment 121, Université Paris-Sud 11 and CNRS (UMR 8617), 91405 Orsay, France
⁴ Centre de Recherche Astrophysique de Lyon (CNRS UMR 5574), Université de Lyon, École Normale Supérieure de Lyon, 46 allée d'Italie, 69007 Lyon, France

Received: 24 May 2007
Accepted: 8 August 2007

Abstract

Context.Instrumental projects that will improve the direct optical finding and characterisation of exoplanets have advanced sufficiently to trigger organized investigation and development of corresponding signal processing algorithms. The first step is the availability of field-of-view (FOV) models. These can then be submitted to various instrumental models, which in turn produce simulated data, enabling the testing of processing algorithms.

Aims.We aim to set the specifications of a physical model for typical FOVs of these instruments.

Methods.The dynamic in resolution and flux between the various sources present in such a FOV imposes a multiscale, independent layer approach. From review of current literature and through extrapolations from currently available data and models, we derive the features of each source-type in the field of view likely to pass the instrumental filter at exo-Earth level.

Results.Stellar limb darkening is shown to cause bias in leakage calibration if unaccounted for. Occurrence of perturbing background stars or galaxies in the typical FOV is unlikely. We extract galactic interstellar medium background emissions for current target lists. Galactic background can be considered uniform over the FOV, and it should show no significant drift with parallax. Our model specifications have been embedded into a Java simulator, soon to be made open-source. We have also designed an associated FITS input/output format standard that we present here.