The ASC is generating a document recommending observing policies to NASA for implementation. This will incorporate present NASA policy and ideas from the ASC staff, the AXAF Users' Committee, and the AXAF Science Working Group (SWG). We are now in the second revision cycle. The Users' Committee first discussed selected items concerning observing policy as summarized in revision I of this document.
The first question was: Should holders of GTO (Guaranteed-Time Observer) time be allowed to compete for GO (General Observer) time? There is no restriction on such proposals from GTO observers in present NASA policy. The Users' Committee thought that, without question, this should be the case during the 15%-GTO-time period, but there was discussion of the fairness of this policy during the 30%-GTO-time period. The Committee also considered whether the IDSs (InterDisciplinary Scientists) should be treated differently from the Instrument Principle Investigators because an IDS share of AXAF GTO time is small. Although not unanimous, the recommendation of the Users' Committee was to let the present policy stand and to allow GTO observers to propose for GO time at any phase of the mission.
The possibility of extensions to the usual one year proprietary time for GOs and GTOs was then considered. An observer might make an argument for an extension which might be approved (or not) by the peer review. The Users' Committee is of the opinion that, all things considered, it is best to have a blanket one-year proprietary time period for all GO and GTO observations. The proprietary clock will start when the observer receives the data and will run separately for each target --- not for a group of targets comprising a project. If there are technical problems completing an observation of a particular target, the observation will be considered complete when 80% of the approved exposure has been achieved.
`Large Projects' were considered next. After discussing the schedule, the burden of proposal writing and review, perceived biases of Peer Review Committees, policies of other observatories, and what is best for science, the Users' Committee made the following recommendations:
1.A Large Project would be one which is so designated by the proposer, would involve one or more targets, and would require 200 ksec or more observing time.
2.There would not be a separate announcment of opportunity to propose, but the Large Projects would be reviewed by a separate panel which could award up to 20% of the GO observing time. The peer review would be guided but not bound to this. Time should, of course, only be awarded to projects worth doing, and the normal Peer Review panels could, if they wished, award time to Large Projects not supported by the special review.
3.Large Projects would be considered starting with the second announcement of opportunity when there will be several months of AXAF data to examine, and source and instrument characteristics are relatively well-determined.
A detailed set of rules for the review of Large Projects was drafted for further discussion with the AXAF SWG and for eventual recommendation to NASA.