Chandra Users Committee Meeting (25-26th April 2007)

SUMMARY Report received 19 Jun 2007


Mark Dickinson
Harry Ferguson
Vicki Kalogera (Wednesday only)
Nobuyuki Kawai (phone)
Smita Mathur (phone)
Jon Miller
Chris Reynolds (chair)
Maria Santos-Lleo
Randall Smith
Lisa Storrie-Lombardi
Allyn-Tennant (ex-officio)
Leisa Townsley.



The CUC continues to be extremely satisfied with the quality and professionalism of support that the CXC brings to the spacecraft operations, data systems, and the user community. The CUC is also extremely pleased by the responsiveness of the CXC to previous CUC recommendations and requests.

On the basis of the presentations and subsequent committee discussion, we have a number of specific comments, suggestions and recommendations for the CXC.

  1. VERY LONG AND EXTREMELY LARGE PROJECTS : The CUC supports both the ELP White Paper review process and the decision of the Director not to proceed with the ELP program. We are concerned, however, that the psychology of both the proposers and the peer review is strongly biased against the longest (3Ms) VLPs that might produce some of the most important science return of the mission. It seems very unlikely that the peer review process would approve a single 3Ms VLP when the total time available for the whole VLP program is capped at 3Ms.

    RECOMMENDATION : The CUC recommends that the total time available for LP+VLP proposals be maintained at 6Ms. However, within that 6Ms allocation, the CUC recommends removing the 3Ms cap on VLPs. In other words, we recommend that LPs and VLPs should openly compete for this time. This would permit the peer review process to accept a 3Ms VLP and still be able to allocate time to a second VLP.

  2. CHANDRA SOURCE CATALOGUE : The CUC commends the CXC for developing a detail schedule for the Chandra Source Catalogue. We remain convinced that the Catalogue will be an important scientific legacy of Chandra. The CUC is concerned, however, that the Catalogue schedule remains very vulnerable to any unexpected events. It has been concerning to see the release date of the Catalogue slip by approximately one year per year, and the CUC worries about a loss of confidence in the CXC's Catalogue efforts by the community.

    RECOMMENDATION : The CUC recommends that, barring unexpected mission-critical occurrences, the CXC/SDS/DS should commit to remaining on schedule, issuing a first release of the Catalogue in Apr/May 08 and a complete formal release in Aug 08. If necessary, additional resources should be directed to this effort to maintain this schedule. The CUC consider the release of the catalog to be of higher priority than the development work on CHIPs and Sherpa; if trades need to be made in order to keep to the catalog release schedule these are areas where slower progress would have a relatively modest impact in the community.

  3. FUNDING OF ARCHIVAL PROJECTS : The CUC has concerns about the funding level for archival work. It was noted that, due to a combination of increased labor costs and reduced funding, it is becoming difficult to support a graduate student and essentially impossible to support a postdoctoral researcher from a single archival award. The CUC fears that the community may not be able to realize the full scientific potential of data from Chandra due to this situation. In addition, we note that the rules of the NASA ADP process have recently changed to allow up to 1/3rd of a proposal to be based on Chandra archival data.

    RECOMMENDATION : The CUC would like to understand the archival program in more detail in order to assess these concerns and make meaningful recommendations. Hence, we request a specific presentation of the archival program in the Fall 2007 meeting of the CUC, including CXC's opinion as to the goals of the Chandra archival program in the context of the new ADP rules.

  4. THE LONGER TERM FUTURE OF CHANDRA : Despite being 8 years old, the CUC feel that Chandra still has a tremendous potential to make new, high-impact discoveries that will significantly add to its scientific legacy. The CUC supports an active discussion of Chandra's future program amongst the community of users. The XMM-Newton mission recently concluded a 3 day meeting on this topic, reviewing a number of proposed long-term projects that could be completed by that mission. Many of these proposals could benefit from an organized program of joint Chandra observations or followup, although we note it would be difficult to win a "joint" very large proposal via either TAC. Consideration of such issues are especially timely given that Chandra will be included in the NASA Senior Review next year.

    RECOMMENDATION : The Eight Years of Chandra meeting in Fall 2007 will be an excellent forum to initiate the discussion of Chandra's long term future science program. The CUC recommends that all invited speakers at this meeting be asked to explicitly address Chandra's future potential for discovery in their specific field of astrophysics. The CUC is aware of and strongly supports previous efforts to collaborate with XMM-Newton, and encourages continuation of these efforts in considering ways to collaborate on longer-term projects (while remaining within the proposal process).