We can expect a huge quantity of important results relating to the Galactic Centre to come from this instrument when mounted on the Gran Telescopio Canarias. This region of the galaxy can only be studied in the mid-infrared given that the line of sight absorption is so high that, even in the near infrared, the extinction is important. An important fraction of the emission from the Galactic Centre is emitted in the mid-infrared range (3-30 microns). CanariCam will allow us to probe this region with greater sensitivity and far higher resolution than any previous study. The resolution of the instrument on the Gran Telescopio Canarias is going to be a key element of the detailed study of Sgr A*. At present, the best existing study of this source at 10 microns, has a resolution of ~1" , although their restoration methods, based in the highly stable PSF of the IRTF, has permitted this resolution to be improved to 0."44 (equivalent to 3000AU at the distance of the Galactic Centre). With the 10-m GTC we can improve this resolution in a further factor of 3, even without image restoration techniques and, if these methods also function in the 10-m, we can even reach a resolution of around 500AU at Sgr A*. Such image restoration techniques offer an improvement of the PSF by a factor of 2 - 3 according to the stability of the PSF. At present, our knowledge of the operation characteristics of OSCIR, on which CanariCam is based, suggest that the PSF will be stable to <0.1 pixel for a 90° rotation of the instrument (a 6-hour exposure).
Observing from ~7.5-25
microns, with diffraction-limited imaging, it would be possible to study
the spatial distribution of the energy emitted by Sgr A* and separate more
clearly the different emission components which are present in this region
of the Galactic nucleus. Such studies have not been possible up to now
because of the strong gradient of emission across the region, which makes
high spatial resolution absolutely necessary in these studies. Space-bound
observatories have had sufficient sensitivity to study this problem, but
their spatial resolution has been too poor to allow them to make a significant
contribution. Earth-bound telescopes can offer better spatial resolution
(although, as we have seen to date is has not been good enough), but at
the cost of a much degraded sensitivity.