MATISSE - the Multi AperTure Mid-Infrared SpectroScopic Experiment - is foreseen as a mid-infrared spectro-interferometer combining the beams of up to 4 UTs/ATs of the Very Large Telescope Interferometer (VLTI).
MATISSE will measure closure phase relations and thus for the very
first time allow image reconstruction on angular scales of 10-20 mas.
Thus, MATISSE will extend the
astrophysical potential of the VLTI by overcoming the ambiguities often
existing in the interpretation of simple visibility measurements.
In addition
to the N band, MATISSE will open three new observing
windows for high-resolution imaging and spectroscopy at the VLTI: the
L, M, and Q band which all belong to the
mid-infrared
domain. Thus,
MATISSE will
- Trace regions with different characteristic temperatures (e.g., N band: 200-400K vs. Q band: 100-200 K). The physical conditions and chemical environment can therefore be studied in different regions (e.g., in proto-planetary disks, or stellar winds)
- Provide images with different spatial resolution (according to the linear dependence of the spatial resolution on the observing wavelength).
- Allow a comparison with lower-resolution images obtained at large telescopes with adaptive optics - tracing the large-scale structure of the scientific targets - in different wavelength regions (e.g., L/M band: NACO/VLT; N/Q band: VISIR/VLT).
Moreover, MATISSE will offer the possibility to perform simultaneous observations in separate bands.
MATISSE will allow one to perform interferometric spectroscopy with different spectroscopic resolutions in the range of R 30-1000. In particular, the spectral resolutions are considered which allow to investigate amorphous dust features, crystalline dust features, emission features of Polycylic Aromatic Hydrocarbons, and - in its highest spectroscopc resolution - even molecular bands. These higher spectral resolutions will allow a fundamental analysis of the composition of gases and dust grains in various environments.
Depending on the individual observing band, unique, new spectral features of dust/gas are accessible. In addition, spectral features that correspond to dust/gas species which can also be observed in N band. Observations in additional bands would therefore for example allow to disentangle the many ambiguities existing in the interpretation of the N band silicate feature.
In summary, MATISSE can be seen as a successor of MIDI at the VLTI by providing imaging capabilities in the entire mid-infrared accessible from the ground. The extension of MATISSE down to 2.7 µm as well as its generalisation of the use of closure phases make it also a successor of AMBER. Thus, in many respects MATISSE will combine and extend the experience acquired with two first generation VLTI instruments - MIDI and AMBER. In terms of image capability MATISSE can be seen as a ground precursor of the future space interferometer Darwin which is presently studied as an instrument sensitive to the 6 to 18 µm range.
In most astrophysical domains which require a
multi-wavelength approach, MATISSE will be a
perfect complement of forthcoming international high angular resolution
facilities such as
ALMA (the Atacama Large Millimeter Array). MATISSE covers the
mid-infrared spectral domain,
between the near-infrared domain, for which many interferometric
facilities are developed,
and ALMA which will operate at (sub)millimeter wavelengths. With the
extended wavelength
coverage from the M to the Q band, MATISSE will not only allow one to
trace different spatial
regions of the targeted objects, but also different physical processes
and thus provide
insights into previously unexplored areas (such as the investigation of
the distribution of
volatiles in addition to that of the dust).
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The
Circumstellar Environment of Young Low- and Intermediate Mass Stars Does the brightness profile
show evidence for dust grain growth and
sedimentation? |
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The Formation of
Massive Stars
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Resolving the planetary regions
of exo-zodiacal dust disks.
Image: Rodmann & Wolf 2006
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Extrasolar PlanetsMATISSE has the potential to
detect extrasolar
giant planets with differential
interferometry. Differential interferometry will allow to achieve an
equivalent increase of
the spatial resolution information of a factor of 10. It will generate
a relative astrometric
measurements between the images at different wavelengths. In the case of an observation of a source with multiple components like a binary or a star plus a planet for instance, for which a simple model of the source can be supposed, we expect that the differential method will give access to the measurements of very high contrast between the components or of very highly contrasted components. By this way the possibility of observing "hot Jupiter"-like planets will be studied. The L and the M band yield
potentially the
best possible ratio between the signal expected
from a Pegasi planet and the error resulting from the still relatively
limited background.
The L and M flux ratios yields a much better constraint on the
temperature for example. |
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Dust and Winds from Evolved StarsRed Super Giants: Bipolar outflows?Asymptotic Giant Branch Stars: Clumpy environment?R Coronae Borealis: Localization of dust clouds formationPost-AGB, RVTau: Geometry of the disk torusSymbiotic stars/Novae: The role of binarityPlanetary Nebulae [PN]: Disk geometrySince
the
interplay between stellar pulsations (probed by the gas-phase molecular
diagnostics
in the MATISSE spectral region) and dust formation (probed by the dust
diagnotics accessible
to MATISSE) is of key importance, simultaneous observations at thermal
IR wavelengths is
essential.
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The Environment of Hot Stars
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Active Galactic Nuclei
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