Top End

Andy Adamson

Associate Director of UKIRT

Troubling the scorers again

The past six months have seen a complete revival in UKIRT's science output, since the atrocious weather reported in the last newsletter (see Thor's article at the end of this issue for more quantitative detail on the weather losses incurred in the Spring). Accepting the seriousness of the situation, the TAG considered a number of projects for carry over from the Spring Cassegrain block, and many of these projects fared very well in the early parts of 06B.

UIST improvements

Work has progressed well on replacing the bespoke EDICT controller with an off-the-shelf unit from SDSU. Matched with a PC-based acquisition system identical to those which control the four WFCAM chips, this will provide useful compatibility with the WFCAM systems and a significant improvement in UIST readout, which should now be "array limited" and permit full array readout in all wavebands. Preparation is now nearly complete; installation of the new controller, and initial on-sky commissioning, are scheduled for the last few nights before we switch back to wide-field mode in late October.

WFCAM and UKIDSS

Work on image quality continued through the Spring/Summer WFCAM schedule block and resulted in a marked improvement in performance over the sky, with a floor now around 0.5 arcseconds and consistent image quality over the sky. Direct moon ghosting is now well understood (as reported in this issue) and a solution is in production for the upcoming WFCAM block. Operational efficiency has improved in a number of ways: at the start of WFCAM operations in 2004, it was not known how long the process of switching between Wide-Field and Cassegrain modes would take. However, the JAC ETS group now deliver the telescope back into science production with only two or three nights of downtime - remarkably quick for such a complex operation. By comparison to some early estimates, this will save more than 500 hours of observing time over a five-year period. While a small amount of engineering/checkout time is usually scheduled after changing modes, an increasing fraction of this time is returned to queue observing. Overall, our capacity to efficiently interleave Cassegrain projects with wide-field survey is now quite well established, from engineering through time allocation and the flexible scheduling of projects within relatively short blocks of Cassegrain time.

Since the previous newsletter, the first major release of UKIDSS data to the ESO community has taken place (also reported within). The great success of this release reflects a huge effort by a highly talented group of people, and we congratulate the UKIDSS consortium on a job extremely well done.

Polarimetry

In a quiet development which has taken place over the last two or three semesters, a significant fraction of UKIRT observing time has come to involve polarimetry. The details of the projects involved vary and both imaging and spectropolarimetry are represented, and it is good to see a number of different groups taking advantage of the polarimetry facilities. At the time of writing we have just entered a two-week spell in which the summit-status project will almost invariably involve polarimetry (some of it circular). Although some of these projects have been done in semi-classical mode (flexed in blocks because of specific flat-fielding requirements, for example), polarimetry can and has been done in the normal flex queue and it is fair to say that it is a very solidly established mode which is serving an increasingly wide community.

In the Background

All of the above developments and outputs measure up very well against the JAC mission statement. They do come at a time of uncertainty over the future, as detailed in a recent message to the community from the Director JAC (linked to from the UKIRT home page). This issue of the Newsletter, which has had to be significantly expanded to accommodate even a subset of the recent developments and highlights, shows that UKIRT remains a vibrant and highly productive observatory with an enthusiastic user community and plenty of capacity to both accept and drive changes. There are undoubtedly many challenges ahead.