Intramolecular Hg⋯π interactions of d-character with non-bridging atoms in mercury–aryl complexes

The late transition metal mercury, known for its propensity to not share 5d electrons, actually does so in short-range π-bonding and medium- to long-range π-interactions.

Integer ambiguity resolution in phase closure imaging

Phase calibration is the key operation of phase closure imaging. In the case of nonredundant arrays, the related problem amounts to finding the node of a Z lattice closest to the end of a vector, the components of which are the differences between the closure phases of the data and those of the model. The aim of the paper is to show that this integer ambiguity problem can be solved in a very efficient manner. Its potential instabilities can also be well identified. The corresponding approach, which can be extended to redundant arrays, revisits and completes the analysis presented in a recent paper entitled "Phase calibration on interferometric graphs" [J. Opt. Soc. Am. A 16, 443 (1999)]. The procedures of self-calibration must be modified accordingly. The spinoffs of this approach also concern the integer ambiguity problems encountered in the global positioning system.

Laboratory imaging stellar interferometer with fiber links

We report on the implementation of an end-to-end imaging demonstrator to validate the concept of optical fiber use in high-resolution aperture synthesis in astronomy. As the coherent transport of light has been conclusively investigated, this study is focused primarily on the accuracy and reliability of the experimental data. In the framework of the European Space Agency project Optical Aperture Synthesis Technologies (OAST), the telescope array's complexity is minimized such that a realistic concept for a future space mission can be proposed. The reconstructed images are obtained by use of a particular self-calibration procedure that was designed to process the visibility contrast and the related weak phase information (one phase closure for each visibility triplet).