On the basis of the above science goals, ISAC reached a clear consensus
as to the appropriate phasing of capabilities that would minimize costs
and maximize possible scientific benefits both in the short and long term.
The recommendations are:
1. That the VLTI should be brought into operation as soon as possible.
2. That the development of VLTI should proceed in sequenced phases
of increasing complexity, leading to the full implementation of the VLTI
as endorsed by previous committees.
3. That the earliest phases should focus on:
(a) the near- and mid-infrared regimes (1-5 microns and 10-20 microns)
(b)
the provision of single-mode instruments (i.e., a beam-combining instrument
which covers a field of view equal to the extent of the Airy disk of an
individual telescope of the array) for both of these wavelength regimes
(c)
the implementation of a narrow-angle astrometric capability in the
near infrared
(d)
the deployment of three 1.8m ATs with low-order adaptive correction
(i.e., tip and tilt)
(e)
the incorporation, at the earliest time possible, of two UTs augmented
with low-order adaptive correction (i.e., tip and tilt)
(f)
the capability to operate with up to four array elements simultaneously
so as to permit reliable phase retrieval and imaging using closure techniques
4.
That the later phases should allow:
(a)
operation at shorter wavelengths
(b)
incorporation of higher levels of adaptive compensation
(c)
operation using all four UTs as well as the auxiliary array elements
The reaction of the whole ESO community to the ideas outlined in this
article is warmly encouraged, and indeed may be pivotal in better defining
ESO's programme. Please feel free to contact any of the ISAC members listed
here or send e-mail to isac@eso.org. We also invite everyone with
an interest in the scientific potential of VLTI to attend the ESO Workshop
in Garching on June 18-21 where we look forward to constructive feedback.
