An Overview of the MATISSE Instrument — Science, Concept and Current Status

MATISSE, a second generation Very Large Telescope Interferometer (VLTI) instrument, is a combined imager and spectrograph for interferometry in the 3-5 μm region (L- and M-bands) and the 8-13 μm window (N-band). MATISSE builds on the experience gained with the VLTI’s first generation instruments. It employs multi-axial beam combination while also providing wavelength differential visibility and phase, and closure-phase aperture-synthesis imaging at a range of spectral resolutions. MATISSE is designed for a broad range of science goals, and its potential for studies of the discs around young stars and active galactic nuclei are highlighted. The instrument concept and operating modes are described; construction is in progress towards installation at the VLTI in 2016.