NaCo

Novelties in CfP-P82

News in the Call For Proposal for P82

As of P82, the following guidelines are in place

SAM - Tentatively offered, pending commissioning: sparse aperture mask interferometry uses special aperture masks in the pupil wheel to obtain the very highest angular resolution at the diffraction limit. When used correctly, these masks transform the single 8-m telescope pupil into a sparse interferometer array, and it is therefore necessary to understand the principles of optical interferometry and in particular the recovery of complex Fourier data (amplitudes and phases) from the Fizeau interference patterns that result. SAM is offered in VM only.
Cube mode- Tentatively offered, pending commissioning: this mode is a variant of the of the burst mode already offered with VISIR and ISAAC. In this mode, a data-cube with each single DIT frame is saved. This mode is particularly interesting for lucky-imaging type of observations, where one wants to select the best frames out of a set before co-adding them. The mode is not suited for time resolved applications, since we have no way to time-stamp each single DIT frame and we occasionally lose frames. There are stringent limitations to the use of this mode, in particular it will only be offered in combination with basic imaging (no LGS). This mode is only offered for VM proposals.
Pupil tracking mode for imaging applications (includes coronagraphy and SDI+) - Tentatively offered, pending commissioning: Pupil tracking mode is being implemented to support SAM, but given the demand from the community, it will be tentatively offered for use with imaging and coronagraphic observations. In this mode, the telescope, independently from NaCo, tracks the pupil instead of the field. This new tracking mode opens the possibility to do Angular Differential Imaging (ADI), a high contrast imaging technique that reduces quasi-static speckle noise and facilitates the detection of earby companions. More work is needed to characterize the mode and to make it available to the community, but it is hoped that full or partial availability will be ready in time for P82. Given its complexity and novelty, pupil tracking is only offered in VM.
Chopping will be offered again in P8, for both M' and L'.There more stringent limitations on the brightness of the AO star and on the size of the chop throw.
Fabry Perot will not be offered.
SDI is decommissioned and replaced by SDI+.
Polarimetry is offered with the Wollaston_0 and retarder plate only.
Special calibrations: all observations requesting special calibrations will be moved to VM. Exceptions to this rule will be considered on a case by case basis during technical feasibility.

As of P81, the following guidelines are in place:

A new mode, which combines SDI+ and 4QPM (in H), will tentatively be offered in P81 in visitor mode only. Characterization of this mode is at this time not complete, further commissioning tests are scheduled for September, 2007. This mode is expected to improve the search for methane companions, like giant extra-solar planets around young stars. At the moment of writing, this mode is not fully commissioned and characterized. but we expect to have it ready for the start of P81. Preliminary results indicate that a contrast of ~20 can be achieved (see example plot).
For technical reasons, the Fabry-Perot mode is not offered. Moreover, all modes that made use of chopping (imaging and polarimetry in M' and coronagraphy with LW filters) are temporarily not available.

Flatfield image of the 'old' SDI

Flatfield image of the "new" SDI (=SDI+ mode)