The Suzaku satellite has provided unique X-ray data from 0.2 to 600 keV with its combination of the X-ray Imaging Spectrometer (XIS) and Hard X-ray Detector (HXD) since its launch in July 2005. The Suzaku mission solicits Key Project proposals, initiated in AO-4, for the next observing cycle (AO-5) from April 2010 through March 2011. The Key Projects are defined as comprehensive observing programs sampling a number of objects of a particular class, or surveying a large region of the sky, in order to take maximal advantage of the unique attributes of Suzaku to address important astrophysical problems. Investigators are invited to propose Key Projects to NASA or JAXA. As these projects require a substantial investment of observing time, proposers are encouraged to include in their team US and Japanese collaborators.

The Suzaku project plans to reserve up to 2 Ms annually for the Key Projects, by drawing time from the US-J collaborative category and both US and Japanese national times. It is expected that at least 2 Key Projects will be underway at any time. If a Key Project requires more than the time available in a year it will be extended until complete.

Key Projects will be solicited annually. As existing Key Projects are completed, new ones will be initiated. Ongoing projects that take more than one year to complete will be reviewed annually to ensure they are being productive.

Proposals

Key Project proposals have the same components of ordinary guest observer proposals. They consist of a scientific justification, a feasibility demonstration of both observations and program, and a target list. The scientific justification must explain the scientific problem, how the proposed observations address this problem, and how the proposed program makes use of the strengths of Suzaku. The Suzaku project expects that the the Key Projects data will not be of temporary scientific interest, instead remaining as a legacy of Suzaku for a long time to come. All Key Project proposals must be written in English. Up to 8 pages are allowed for the science justification (text, figures, and tables).

Data rights

All Key Project data flow directly into the Suzaku public archive. This guarantees maximum exploitation of the data. The PI of a successful proposal will be expected to serve as the scientific lead for observation planning.

Time critical and ToO Key Projects

Operational constraints preclude the possibility that a Key Project consists entirely of time constrained observations or ToOs. It is possible to include in a Key Project a subset of constrained observations. As is the case for constrained observations during the regular proposal cycle, the imposition of a constraint or the need for a ToO must be well justified. 15% is the guideline of TC+ToO time for Key Projects.

Proposal selection

For selection in AO-5, Key Project proposals will be solicited and submitted as part of the AO-5 call for GO proposals. The initial screening of these proposals will be made by the respective national review panels. The final selection of Key Projects will be made at the Suzaku international merging committee meeting. Proposers with highly ranked proposals in the national programs will be invited to present and discuss their proposal in a Key Project workshop to be held in Japan between late February and early March, 2010, which is completely open to all scientists. The final selection of the Key Projects in AO-5 will be made in the merging committee meeting immediately after the workshop. Note that all PIs of the on-going key projects selected in AO-4 are required to participate in the Key Project workshop to present an overview their achievement so that the merging committee can judge whether the program should be continued in AO-5 or terminated in AO-4. If the PIs of the on-going key projects need to change their observation strategy, such as increasing number of targets or exposure time etc., they should resubmit the proposal.

Since the Key Projects will be selected at the same time as targets for the general guest observer program, care will be exercised to minimize disruption of the general program. In particular, if a target proposed in a Key Project appears in a regular GO proposal with an equal or longer observing time and is ranked A or B, the target will be awarded to the PI of the regular proposal, with full one-year proprietary rights.

Selection of Key Projects in subsequent rounds might be performed through a separate solicitation from the general call for observing proposals.

Proposal Submission to US

Principal Investigators (PIs) affiliated with institutions in the US should submit Key Project proposals to NASA for X-ray observations with the Suzaku observatory from April 2010. PIs outside the US must submit their proposals to ISAS/JAXA. It is forbidden for the same group to submit identical Key Project proposals both to NASA and to ISAS/JAXA. Key Project proposals that require more than 1 calendar year are allowed, unlike for the regular proposals. Key Project proposals to NASA are due at 4:30 EST on Friday, November 20, 2009, to be submitted electronically using the ARK/RPS system. Detailed instructions, including the link to the ARK/RPS system, will be published in September.

We also intend to update the Technical Description document, as well as planning tools, with latest information in mid September; existing versions should suffice for early planning of proposals, but may not give accurate results when detailed simulations are performed.

On-going Key Projects since AO-4

The following Key Project programs have been going on in AO-4