Post-processing the VLTI fringe-tracking data: first measurements of stars
Abstract
Context: At the Very Large Telescope Interferometer, the purpose of the fringe-tracker FINITO is to stabilize the optical path differences between the beams, allowing longer integration times on the scientific instruments AMBER and MIDI.
Aims: Our goal is to demonstrate the potential of FINITO for providing H-band interferometric visibilities, simultaneously and in addition to its normal fringe-tracking role.
Methods: We use data obtained during the commissioning of the Reflective Memory Network Recorder at the Paranal observatory. This device has permitted the first recording of all relevant real-time data needed for a proper data-reduction.
Results: We show that post-processing the FINITO data allows valuable scientific visibilities to be measured. Over the several hours of our engineering experiment, the intrinsic transfer function is stable at the level of ±2%. Such stability would lead to robust measurements of science stars even without the observation of a calibration star within a short period of time. We briefly discuss the current limitations and the potential improvements.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- January 2009
- DOI:
- 10.1051/0004-6361:200810613
- arXiv:
- arXiv:0812.2328
- Bibcode:
- 2009A&A...493..747L
- Keywords:
-
- instrumentation: high angular resolution;
- instrumentation: interferometers;
- techniques: high angular resolution;
- techniques: interferometric;
- Astrophysics
- E-Print:
- doi:10.1051/0004-6361:200810613