If a science project requires observations with both NuSTAR and XMM-Newton, then a proposal may be submitted to request time on both observatories.
By agreement with the NuSTAR Project, the XMM-Newton Project may award up to 1.5 Ms of NuSTAR observing time. The time will be awarded only for highly ranked proposals that require use of both observatories and shall not apply to usage of archival data. The only criterion above and beyond the usual review criteria is that both sets of data are required to meet the primary science goals. Proposers should take special care to justify both the scientific and technical reasons for requesting observing time on both missions. It is not essential that the requested NuSTAR and XMM-Newton observations be simultaneous, however clear discussion of the required level of coordination is essential for evaluating feasibility. No NuSTAR time will be allocated without the need for XMM-Newton time on the same target to be obtained within this AO cycle.
No observations with a reaction time of less than 3 working days from an unknown triggering date will be considered for this cooperative programme. It is the responsibility of the PI to inform both observatories immediately if the trigger criterion is fulfilled.
Observation of high count rate targets with NuSTAR (50 cps/NuSTAR module) require special planning and increased downlink capacity. Such observations should be carefully justified, and should not be feasible with other less-sensitive hard X-ray observatories.
Establishing technical feasibility is the responsibility of the PI, who should review the XMM-Newton Calls for Proposals and the NuSTAR web-page (http://www.nustar.caltech.edu/for-astronomers). For efficiency reasons NuSTAR observations should not be shorter than 20 ks. For each target the total requested XMM-Newton observing time should be comparable (within approximately a factor two of) the total requested NuSTAR observing time. As NuSTAR is not an observatory type mission, and does not have funding to support a Help Desk or general analysis or calibration support, each successful proposal will be supported by an instrument/calibration scientist, who will be nominated by the NuSTAR project. It is mandatory that the support scientists will be offered the opportunity to participate on the analysis, interpretation and publication of the obtained data. There is a one-year exclusive use period for the NuSTAR data, which were successfully competed as part of the XMM-Newton AO. The one-year exclusive use period starts with providing the NuSTAR data to the observer.
Proposals for joint observing time may be submitted both by the NuSTAR team or by independent proposers. Evaluation of investigations will be based solely on the quality of the proposed investigation.
All standard observing restrictions for both observatories apply to joint proposals. For proposals that are approved, both projects will perform detailed feasibility checks. Both projects reserve the right to reject any approved observation that is in conflict with safety or mission assurance priorities or schedule constraints, or is otherwise deemed to be non-feasible.
Scientists can apply for the joint programme in the ``Observation Form'' of the XMM-Newton RPS. For each observation the PI has to specify the required observing time for both observatories. The ``Comment'' field should be used to briefly describe the NuSTAR instrument modes and scheduling constraints.