In newsletter issue No. 6 (October 2002) we reported
on the construction of the new ‘long camera’ for WYFFOS, the multi-object
spectrograph used in conjunction with AF2 and INTEGRAL.
It is a pleasure to report that this camera was successfully commissioned,
in fact at the time of writing the final commissioning run is underway. First
indications are that the camera is performing to specification, full details
will appear on the AF2 web pages in due course. We currently use the two-chip
EEV array with the long camera, which while it has excellent blue response,
suffers from significant fringing in the red. We are actively pursuing the
purchase of CCDs with good overall efficiency and fringing characteristics.
When the array is used with AF2 the dispersion direction is aligned with the
array such that one looses one central fibre and care should be taken to
park this fibre when field configurations are performed. The new camera permits
the placement of 150 fibres on the CCD array, and typically gives 4-pixel
sampling per resolution element, equivalent to resolving powers of approximately
5000 and 1500 with the 1200R and 600B gratings respectively (depending on
wavelength). When the long camera is used with INTEGRAL it is rotated by
90 degrees leading to gaps in wavelength space which need to be taken into
account when defining a central wavelength.
The long-slit intermediate resolution infrared spectrograph, LIRIS, is offered
in both imaging and long-slit spectroscopy modes. LIRIS in multi-slit mode
is available only in collaboration with the instrument builders due to the
very long lead time required with the mask creation and insertion into the
cryostat. Prospective applicants for LIRIS in this mode should contact Arturo
Manchado (firstname.lastname@example.org) in the first instance.
In the current year further commissioning will take place during which the
multislit mask operations are further fine-tuned. In addition, several technical
improvements have to be verified on sky (e.g. new sandwich holders for the
long slits), and a thorough quantification of the image quality will be performed.
Presently it is only possible to use the low resolution grism (R~1000), the
higher resolution spectroscopic mode (R~3000) and the polarimetric modes
of this instrument are delayed pending purchase of the relevant grisms and
prisms. Since the performance of LIRIS in imaging mode is very similar to
that of INGRID, we do not plan to offer the latter at the Cassegrain focal
station while LIRIS is operational.
Override observations of targets of opportunity are an increasingly important
aspect of telescope operations. At any given time we have a number of active
override programmes and, due to the nature of the time-split at ING between
four separate TACs, the rules and restrictions applying to these programmes
are rather complicated. Those interested in applying for such programmes should
therefore familiarise themselves with the information on our web pages at
It may well be the case that a cross-TAC approach would make most efficient
use of telescope time and maximise chances of a successful override campaign.
The WHT and INT are now part of the EU funded access programme managed under
the auspices of Opticon. Applicants awarded time on these telescopes under
the normal peer review processes, but who are not eligible for financial support
from the telescopes’ funding agencies, may apply to support under this access
programme. The programme is funded to run from January 2004 until December
2008, and full details of the scheme can be found at http://www.otri.iac.es/eno/. ¤