REPORT FROM THE JCMT UKTAG
Semester 04A

Summary

The JCMT UKTAG received 53 proposals for consideration in semester 04A, representing a slight but not significant increase from previous semesters. Of these proposals, 31 (58%) were awarded time in the UK queue. In addition, 3 long term programmes were carried over from previous semesters, including the SHADES project which is progressing well.

After removal of the observatory's engineering requirements, Director's discretionary time, and the University of Hawaii fraction, the UK's allocation for semester 04A amounted to 142.5 shifts. The total request (including the long term projects) was for just under 242 shifts, giving an oversubscription factor of 1.7.

The successful proposals and their allocations are posted on the JCMT web-site .

Weather Statistics

Weather queues 1-3 continue to be the most sought after, driven by the demand for SCUBA. The graph below shows the fraction of projects allocated time in each weather queue for 04A.

Allocations in weather queues 1-2 represent 60% of the total time awarded. The weather statistics over the past few years show that tau_CSO < 0.08 occurs for ~30-40% of the time, peaking as high as 60% and dropping as low as 10%. This clearly varies with season and climatic conditions such as El Niņo, but, as usual, we expect that a lot of observers will leave the telescope disappointed by the weather!

In many respects, the graph above reflects the importance of a flexibly scheduled queue for getting the most highly ranked proposals completed on the shortest timescale, and the new OMP clearly has a role to play here. Unfortunately, it also dramatically illustrates the dearth of projects we have to flexibly schedule when the weather is relatively bad.

Instrument Statistics

The graphs below show the distribution of proposals, received and allocated time, across the JCMT instrument suite. The top graph shows the fraction relative to the total number of shifts in that category, while the bottom graph shows the number of proposals.

Naturally, as SCUBA dominates the number of proposals we receive a large fraction of the scheduled time (67%) goes to SCUBA projects. This is shown in the top graph. The flip-side of this is shown in the bottom graph which indicates that most of the proposals that are rejected (the difference between the two columns in the lower graph) are also SCUBA ones. Conversely, the fallback projects are dominated by projects requesting the A and B band receivers.

The Receivers

The RxA and RxB instruments still remain popular instruments for the JCMT UK community. From the graphs above, one notices a tendency for RxA time to be awarded as fallback. Although there is no remit for the TAG to do this, it does relieve pressure from the shift allowance (impacted by SHADES) and frees the TAG to allocate more science programmes than it normally could. It is timely at this point to remind people that fallback does not correspond to a low-rank and it is hoped that, with a properly flexible schedule as we now have, these projects will be completed. Furthermore, the weather statistics are in favour of the completion of RxA fallback proposals.

Only four proposals requesting RxW were received. One was awarded time in the ANS queue (see later) and the other in the fallback queue, providing 'good-weather' cover for when SCUBA is warmed up.

SCUBA & SCUBA-polarimetry

SCUBA still remains the most requested instrument in the UK queue. The request for, and allocations of, polarimetry time remains healthy and steady (the top ranked proposal this semester was for polarimetry).

Thumper

Once on the telescope, Thumper will be a unique instrument with unique capabilities at 200?m. It continues to generate a significant amount of interest in the UK queue and of the 4 proposals received this round, 3 were awarded time totalling 7 shifts.

What are the UKTAG looking for in proposals?

A significant fraction of proposals received are resubmissions (sorry, no graph!). Twenty-one of the 04A proposals are identical or very similar to proposals submitted in previous rounds. Some are to complete on-going projects which have been adversely affected by weather or instrument/telescope faults. Others are resubmissions of proposals which did not originally get time. The TAG have noticed and commented on the fact that very few of these refer or are seen to respond to any previous feedback given. The Panel do look at resubmitted proposals and to whether previous feedback has been addressed. The feedback is intended to help improve proposals and the TAG refers to it when reading resubmissions. If a proposal is being resubmitted, then please refer to the feedback, even if you found it unhelpful!

At times it is still difficult to find projects which can be flexed against SHADES. As a reminder, SHADES operates within the ?CSO = 0.05-0.1 weather band as measured on the WVM radiometer, with fields centred around the 02h and 12h RA range. Proposals targeted at these RA ranges (outside of the SHADES weather band) are very welcome by the TAG and the JCMT scheduler!

Finally, the Panel still do look for large and ambitious programmes (of the order of 8-10 shifts). A caveat to this is that when such large programmes are received they are naturally scrutinised more carefully by the Panel, assessors and referee(s) alike.

What is ANS anyway?

We have had a number of queries as to the meaning of ANS. It stands for "Allocated but Not Scheduled" and is intended for top ranked proposals requiring good weather conditions. It is a special flex queue which was invented in response to the SHADES programme. The SHADES allocation of 30 shifts per semester carries with it 40 flex shifts to help ensure its success - these 40 shifts have to be filled from the queue somehow. If there is a top ranked proposal, and especially one which requires good (i.e. band 1) weather, then it is given an allocation but not actually slotted into the schedule. It is specifically meant to be flexed against the SHADES time on the telescope, so essentially an ANS project awarded 3 shifts of band 1 weather time has a flex allocation of 70 shifts! It is thus hoped that this should see it to completion. According to the weather statistics, we would expect approximately 10 shifts of the 70 to be in band 1.

Another advantage that we see is that the ANS projects do not come out of the allocation budget and instead form a part of the 40 flex shifts allocated to SHADES. 5 projects were awarded ANS status in 04A, totalling 7 shifts, each requiring band 1 weather.

The SHADES observers have agreed to cover the observing, but if the PI of the ANS programme wants to travel to the telescope for some period (during the appropriate scheduled SHADES block) to do their own observing then they can do. PI's of heterodyne projects awarded ANS time are probably well advised to come out.

Antonio Chrysostomou (University of Hertfordshire)
Chair - UKTAG

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