Scientific Rationale
MAD and Beyond: Science with Multi-Conjugate
Adaptive Optics Instruments
ESO has pioneered the use of adaptive optics assisted instruments for research in Astronomy. Come-On+ and its heir Adonis were the first common-user adaptive optics instruments in the world. Nowadays adaptive optics (AO) instruments are standard at all major observatories, and AO adapters are routinely used to feed spectrographs requiring very small entrance windows to achieve very high spectral resolution, such as CRIRES, or to increase the spatial resolution of 3D spectro-imagers such as SINFONI on the VLT. And of course AO adapters are indispensable for the VLTI. The biggest shortcoming of AO instruments is their small corrected field of view, which is limited by the size of the isoplanatic patch that even in the IR and in the best sites rarely exceeds 15 arc-seconds. The ESO Workshop on AO in Venice in 2001 paved the way, on the basis of theory and simulations by researches in Europe and the USA, to overcome the isoplanatic barrier: atmospheric tomography.
The study phase for the European Extremely Large Telescope (E-ELT) provided the opportunity to actually demonstrate that atmospheric tomography, through its most known version of Multi-Conjugate Adaptive Optics (MCAO), can provide AO performance over fields of view significantly larger than the isoplanatic patch. This led to the construction of the Multi-conjugate Adaptive-optics Demonstrator &ndash MAD &ndash for the VLT. Thus, about 20 years after the deployment of the AO demonstrator Come-On at the 3.6m telescope of La Silla, ESO again pioneered the field by commissioning MAD on UT3 at the VLT. The commissioning was so successful in fact, that a strong demand from the community led MAD to be offered for scientific observations initially for 14 nights in the Chilean summer of 2007/2008 and then, again at the request of the community, for additional 9 nights in August 2008 to cover the winter period. One year after the first science demonstration run, close to 10 papers based on MAD data have been published and many others are in preparation, showing that indeed the community is ready to apply MCAO techniques to ambitious astronomical problems.
The success of MAD also demonstrated that the technology and the community are mature for the next generation of MCAO instruments. The aims of the workshop, therefore, will be twofold: to celebrate the achievements of MAD through a dedicated discussion of its design constraint and its scientific achievements, and, with the strong foundation of the scientific results of MAD, to outline the high level requirements for the next generation of MCAO instrument. Thus, the spirit of the conference will be both festive, because we are celebrating MAD, and oneiric, because we are dreaming about the future.