- Fibre Feed to Coude
- The SAC recommends that the CFHT
proceed with the development of a Cassegrain
fibre feed to coude; but recognizing that the
CFHT has no cross- dispersed spectrograph
capability, the SAC suggests that the polarimetry
module not be included in the present
development, as the limited wavelength coverage
available at coude will make such a facility
uncompetitive.
- Seeing Monitor for Mauna Kea
- Gemini North has expressed interest in
a seeing monitor facility for purposes of flexible
scheduling. As a shared facility, this might be
used for better site characterization and for the
optimization in real time of observing programs
on the various Mauna Kea telescopes --
particularly when adaptive optics instrumentation,
such as the CFHT AO bonnette, may be in use.
One possible implementation is to use two
existing radio antennae employed in recent
atmospheric tests by SAO (the Smithsonian
Astrophysical Observatory), in preparation for the
submillimeter array, as the basis for a communal
seeing monitor facility for optical and IR
observations on the summit. The SAC raised
questions about whether radio phase monitors
could provide useful information on optical and
IR seeing, and also about the degree to which
measurements from the SMM site (by the JCMT
and CSO) might be representative of seeing
conditions on the summit. (It was noted that in
tests done by ESO there was difficulty in using
data from a seeing monitor to estimate telescope
seeing conditions, when the two sites were
widely separated). However, the SAC felt that in
view of the potential benefits of a shared facility,
and preliminary interest expressed by Gemini
and Keck, that a more detailed investigation of
ways of implementing such a facility should be
made. The time scale set by the Gemini
requirements would require this be ready by
mid-1997.
The SAC thus encourages the CFHT to
explore the possibility of a common user seeing
monitor facility, and to present a more detailed
report at the next SAC meeting.
- Status of New Guest and Visitor
Instruments for CFHT
- While an increasingly large number of
time request proposals involve use of CFHT
instruments operated in standard configurations,
a small fraction of them are based on either
additional modifications of these configurations,
or even full development of new observing
modes in these instruments. In many cases, no
full assessment of technical issues and needed
manpower are presented by applicants.
In view of the importance of coherently
planned work, efficiency and reliability of CFHT
instruments, SAC fully endorses the point of view
of the Director, that, in case of insufficient
preparation and prior contact with CFHT, and
irrespective of the scientific value possibly
recognized by Time Allocation Committees, the
proposal will not be accepted by the Executive.
- New Policy for the Purchase of Filters
and Grisms.
- Since CFHT is frequently asked to
purchase filters or grisms by observers, the
executive felt it was time to establish rules
regarding such purchases. They proposed the
following policy:
- The Principal Investigator of a program who
wants CFHT to buy a new filter or a new grism,
must contact in writing the CFHT Director,
justifying the request, before the deadline for
submission of observing time requests. CFHT's
Director will inform the appropriate TAC if CFHT
will buy the required filter or grism, or not.
- The forms for proposals will have to be
completed correctly: the PI is responsible for
making a clear statement on the filters and
grisms which are required. In cases where the
Director was not contacted in advance of the
deadline, CFHT will not be committed to buy any
filter or grism just because a proposal is selected
by the Canadian Telescope Assignment
Committee.
- The decision by CFHT on grisms or filters
selected for purchase, will be communicated to
CTAC together with the technical appraisals of
the time requests:
- if the filter or grism is considered for common
use for the future, CFHT will purchase it
- if the filter or grism is strictly related to the
special observations requested by the observer,
CFHT will help, if requested, in the specifications
and the selection of vendors but the the observer
will have to purchase them.
- in some less clear-cut cases, if the observer
agrees to leave the filter or grism at the disposal
of other observers, CFHT and the observer will
share equally the cost.
- if the number of filters and grisms requested in
one year exceeds the budget allocated for this
purpose, CFHT will ask TAC and/or SAC to
prioritize the requests to be satisfied.
- For filters, a three month delay between the
order and the delivery is common. As soon as
the schedule of observations for the semester is
known, the procedure to order the filters has to
start. CFHT will not be responsible for slow
response from the observers or for unforeseen
delays from the vendor.
For grisms, it takes between five and seven
months to get a delivery, so clearly the order
needs to be prepared well in advance of the
telescope time request.
- Requests not documented in the time request
form and coming after selection process could be
ignored and CFHT is in no way obligated to
satisfy them.
SAC endorses this policy which will be
explicitely stated in the next CFHT Bulletin.
- CFHT on Mosaic.
- The CFHT staff has devoted a
substantial effort to develop and improve the
CFHT Homepage on the World Wide Web
(WWW) which is accessible via Mosaic. This
new tool provides a direct access to the most
recent information regarding CFHT's activities,
especially the latest news on instrumentation,
and is therefore extremely useful to the CFHT
applicant. In particular, it avoids the publication
delays of the CFHT Information Bulletin where
this information used to be found. Thus, as long
as the content of the CFHT Homepage is
regularly updated so that it does indeed provide
the latest information, it will provide the most
important link between the users and the
telescope facilities. The CFHT Homepage will
become very popular as the WWW spreads
within the community, and its continual
development must therefore be actively pursued.
The SAC congratulates the CFHT for producing
such an excellent World Wide Web document
which is both clear and concise. SAC suggests
that the MOS-SIS manual be brought on-line
within the document as soon as possible as well
as any manuals for visitor instruments which are
or become available in this format. The SAC
also suggests that relevant information be
updated frequently -- especially before proposal
deadlines -- and that the date of the last update
be recorded. Finally, SAC recommends an option
be made available to the community which
includes CFHT contact information for
instrumentation responsibilities.
- Infrared Detectors at CFHT.
- The presently available Redeye cameras
will not provide a correct sampling of the PSF of
the Adaptive Optics Bonnette and of OSIS, nor
will they cover adequately the field of these
instruments. If no strong and immediate effort is
made to remedy this situation, the CFHT will not
be competitive in the area of near-IR imaging
and spectroscopy when OSIS and the AOB
become operational.
Several possible solutions were
discussed. The first group of solutions consists in
using parts of the existing Redeye camera, and
imply a rebuild of its optics. There are three
possible options along this line:
- Keep the NICMOS 256 x 256 array unchanged
in the camera; a rebuild of the camera optics will
lead to a correct sampling of the PSF, in order to
take advantage of the superb image quality
behind the AOB, or with OSIS. A serious
drawback of this solution is the resulting reduced
field of view, in particular in the case of OSIS.
- Replace the NICMOS 256 x 256 array in
Redeye with an inexpensive 1k x 1k x 18 micron
array, perhaps with only one quadrant
operational. Such an array could be acquired at
a reasonably low cost. This solution would still
require a rebuild of the Redeye optics to properly
sample the PSF, but the field of view, although
still not optimal, would be twice that of the
previous solution, for a moderate extra-cost.
However, the implantation of a new chip in
Redeye would require significant additional
manpower. CFHT will probably not be able to
provide it within the next year, a time frame that
is dictated by the need to have a proper IR
detector when OSIS and AOB become
operational.
- Purchase a Grade "A" 1k x 1k IR array with 18
micron pixels, and install it in Redeye, after a
rebuild of its optics. With this solution, both the
requirements on the PSF sampling and the field
coverage are met, but the difficulties mentioned
above concerning the necessary manpower to
install such a chip in Redeye are still present.
Finally, the last solution involves the acquisition
of a new IR camera, independent of the Redeye
design. Under this plan the CFHT would acquire
a complete IR camera, with a 1000 x 1000 array
with 18 micron pixels. The recognition that this
was the only practical way to ensure the
availability of a proper IR camera when AOB and
OSIS become operational led to the following
recommendation to the Board of CFHT.
The SAC emphasizes the strong and
urgent need for a near-IR camera with an
adequate sampling of the PSF and an optimal
coverage of the field of the AOB and OSIS. This
detector should be available at CFHT as early as
1996, when both OSIS and the AOB become
operational, so that CFHT can be fully
competitive in due time in the area of non
thermal infrared imaging and spectroscopy.
Considering that the manpower
necessary to develop such a camera in this time
frame does not exist at CFHT, the SAC
recommends the acquisition of a complete IR
camera housing a 1000 x 1000 array, after CFHT
has defined exactly what device is needed. The
SAC recognizes that there is no solution for
funding such an acquisition within the present
CFHT budget in the required time frame.
Consequently, the SAC recommends that an
exceptional capital expense be provided by the
agencies for this absolutely necessary
acquisition.
- Network of Instrumentation Groups.
- The complex set of instruments available
at the CFHT, coupled with the necessarily
measured pace at which the CFHT Information
Bulletin is produced, means that any helpful
insights or "tricks of the trade" developed by one
observer are slow to reach a broad audience.
Understandably, news of problems is generally
more quickly propagated through the user
community, but often in distorted form, with the
result that needless worries are generated.
For this reason, the suggestion has been
made that the community consider the
establishment of instrument-specific Networks of
Working Groups. In the model discussed, one
user would serve as an informal chair to whom
could be transmitted, by electronic mail,
anecdotal end-of-run remarks about insights
gained and problems encountered with the
instrument in question, especially when it is used
in non-standard ways. (These reports would not
supplant the usual end-of-run reports.) In the
ideal model, the remarks would not simply
accumulate in a scrapbook of unrelated ideas,
but would be annotated, cross-referenced and
summarized to provide guidance for future, and
especially first-time, users. A collection of FAQs
(Frequently Asked Questions) with answers
would provide a friendly and helpful introduction
to the instrument.
Clearly, to avoid the propagation of
misleading or incorrect information, the Working
Group information would have to be referred to
the appropriate CFHT personnel as well, and a
close link will need to be established. It would
seem most advantageous, therefore, to use the
Mosaic facility to this end, with the accumulated
wisdom accessible through the CFHT home
page.
SAC proposes that a trial of this concept
would be in order, with MOS as the instrument in
question. DAVID HANES, of Queen's University,
will serve as the chair. When the procedures
involved have been established through
consultation with the CFHT, announcements will
be provided to the community through the
electronic mail network, as well as in the next
CFHT Information Bulletin. We expect the trial to
begin early in the first semester of 1995.
- Preparations for the Users Meeting.
- With the agreement of the astronomers
from the Observatoire de Lyon, it has been
decided that the next CFHT Users meeting will
be held in Lyon, at the Ecole Normale
Superieure (ENS) from May 15 to May 17, 1995
inclusive. The ENS is located in downtown Lyon,
about 1 km from the TGV Perrache station. The
address is:
ENS Lyon
46 Allee d'Italie
69364 Lyon Cedex 07.
The ENS is fully equipped for such meetings,
with large amphitheaters and rooms. At least 2
inexpensive hotels are located nearby which
should be capable of accomodating the 80-120
expected attendees.
The Local Organising Comitee is not yet fully
constituted and operational, but Georges Paturel
and Francois Sibille have taken care of the initial
facets of the organisation. The CFHT person
responsible for the meeting is Marc Azzopardi
who was involved in the organisation of the first
Users Meeting.
This users meeting is the last one before
10-meter class telescopes become fully
operational. In 1998 the second Keck, the
Subaru the first VLT and Gemini North should be
almost finished and in this context we must
address now the crucial problem of the future of
CFHT for the beginning of the year 2000. Hence,
the SAC decided to entitled this meeting "The
Future of CFHT". A large fraction of the meeting
will be dedicated to talks and open discussion
concerning the possible scientific role of CFHT in
the era of the 10-meter class telescopes.
Harvey Richer (richer@geop.ubc.ca)
http://bear.ras.ucalgary.ca/CASCA/w94/sacrep.html (Einblicke ins Internet, 10/1995)