Chandra X-Ray Observatory
	(CXC)

CXC response to CUC Recommendations following 2007 Apr CUC Meeting

> 
> 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.


The  recommendation of the CUC makes a very good point re the
allocation to the VLP and LP programs.  We (CDO) see at least 3 options at
present: 

1. Openly compete the LPs and VLPs for 6Ms allocated to them in total as 
recommended by the CUC

2. Allocate 2Ms to LP and 2Ms to VLP and allow the remaining 2Ms to be 
allocated as the Big Projects Panel recommends

3. Retain the present system of allocating at least 3Ms to LPs and at most 
3Ms to the VLPs

After reviewing these alternatives in a bit more detail, the CXC will solicit 
comments on the options from Chandra Users. We will then discuss the feedback 
with the CUC at the Fall meeting and adopt the approach for Cycle 10 LPs 
and VLPs shortly thereafter.

 
> 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.


The SDS and CXCDS Chandra Source Catalog project team is committed to
developing and releasing the first version of the Chandra Source Catalog
on a schedule consistent with the priorities of the CXC
management and the NASA Chandra project office.  The catalog is the
highest identified priority following support for spacecraft operations.

If needed to maintain schedule, available additional labor will be 
assigned to catalog tasks, and some areas may be subject to de-scoping 
relative to the 0.5 version of the Requirements Document for catalog 
release 1.

Over the last several months significant progress has been made in
support of key science requirements.  To ensure optimal source
detections, effective background determination tools have been developed
and evaluated that determine the ACIS low spatial frequency and readout
streak background components.  Robust source aperture photometry
algorithms have been completed and implemented.  Specifications for
spectral and temporal properties tools are completed and have been or
are being implemented.  Similar progress has been made in the
development of the catalog database and archive software and
enhancements to the automated processing system infrastructure to 
support Level 3 pipeline operations.  Detailed testing of these 
components will be conducted over the next few weeks as part of 
operational performance and science testing of the internal CAT 2.5 
software release.



> 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.


CDO is preparing this presentation, using as input past funded
archival programs, and the archival oversubscription history in proposals
and dollars.  CDO will also informally survey past successful
PIs of archival programs to ask for a list of refereed publications.
We will also ask whether they found the level of funding adequate to
accomplish their proposed objectives. 

 
> 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).


Joint XMM/Chandra efforts were discussed and considered 
at the recent X-ray Grating Spectroscopy Workshop in Cambridge, MA,
and are regularly considered at these annual Chandra Science Workshops.
In addition, Invited Speakers at the Eight Years of Chandra meeting
are being asked explicitly to mention, relevant to their area of scientific
expertise,  investigations that existing x-ray missions should perform
as well as those observations that require the capabilities of planned
x-ray missions.


Smithsonian Institute Smithsonian Institute

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