Date: Thu, 09 Sep 2004 20:58:22 -0300 From: George Mitchell To: Christine Wilson Subject: Re: Gemini TAC procedures Hi Christine: Let me address your three questions separately. I can only speak for the CTAC and ITAC, but I believe that the other TACs follow basically similar procedures. 1. Joint proposals (ie. proposals requesting time from more than one partner): The PI of the application to CTAC is normally one of the Canadian members of the team. Each joint proposal has a "Principal Contact". Gemini communicates with the proposers via this person. The Principal Contact need not be the PI of the Canadian application. The PI of the application to another country would normally be an astronomer from that country. The applications (forms) sent to each partner TAC are (unfortunately in my view) not necessarily identical. Each TAC sees only "its" application. As Chair, I see the other applications (i.e the other components of the joint applications) but only after the CTAC meeting, in preparation for the ITAC meeting. CTAC evaluates and ranks joint applications just as it does non-joint applications. They are not put in a separate category. Before the ITAC meeting, Gemini staff determines the ranking of joint proposals using a weighted average of each partners ranking. (There is a twist here: If one of the partners ranks a joint proposal so low that it does not make that country's time cutoff, that partners ranking is deemed not to exist. In other words, its is as if the application to that country was not made. I have objected to this, but nothing came of it. Very few applications are in this category, so perhaps there is no need to worry.) At the ITAC meeting, joint proposals are looked at one-by-one. In cases where the partner rankings are divergent, Jean-Rene Roy (ITAC Chair) asks us whether we want to change our ranking. In fact this is an important procedural point: ITAC is empowered to change the final rankings of any of the semester's proposals in any way it sees fit. Of course, the TAC Chairs have to justify any major changes to their TACs. 2. The issue of duplicate observations is addressed by the ITAC. There is no set policy to my knowledge. In recent semesters, there have been a number of duplications. These can be single-target proposals with the same target. In my time on the ITAC, there has not been a case in which all the technical details (e.g. integration time, filters, etc.) of the observations were sufficiently alike to warrant one proposal being denied. There are also multiple-target proposals which have one or more target in common. In these cases, the ITAC has made changes to the observing times and has notified the PIs of the reason. 3. There is no special category for legacy-type programs. There are certainly large proposals which return over a number of semesters, but they are evaluated and ranked each semester. There has been a recent policy decision by Gemini to permit a high-ranked proposal to remain in the queue for up to two additional semesters. A proposal must lie in band 1 in the final merged list to be considered for rollover. The decision on Canada's proposals is made by the CTAC (same for others). This is called "rollover". A joint proposal can be rolled over only if all the partners involved in that proposal agree. Another point that may be of interest: CTAC ranks its proposals. Gemini takes all the partner's tanked lists of proposals and merges them according to an algorithm which takes into account each partner's share of the time. The result is a ranked list. This merged list is divided into five "bands", of which the first four use up all of the available time (assuming no losses to weather). Band 5 is backup. In essence, then, there are only four ranks (ignoring band 5). I am not convinced that this gross smoothing is necessary, but Gemini staff are not interested in reexamining the issue. They argue that it greatly simplifies the operation of the queue. I hope this helps. Let me know if you want more! Cheers, George