With the aim of taking full advantage of the complementarity of ESA's observing facilities, it has been agreed to establish an environment for scientific programmes that require observations with both to achieve the desired scientific results. By joint agreement in the current OT2 AO process there is up to 500 ks of XMM-Newton observing time available for allocation by the HOTAC. There is no mechanism whereby the XMM-Newton TAC can allocate observing time on Herschel.
XMM-Newton observing time can be requested for those programmes where the science objectives require:
Simultaneous or quasi-simultaneous Herschel and XMM-Newton observations, or
short (max. 10 ks) snapshot-type XMM-Newton observations of newly detected and likely variable sources which require scheduling within a year after the Herschel observation.
Proposers wishing to make use of this opportunity have to submit a single proposal in response to the Herschel OT2 AO indicating the request for XMM-Newton observing time in the appropriate section of the proposal submission form. Although time is requested on both observatories, it will be unnecessary to submit proposals to two separate TACs. The science case for all proposals submitted to Herschel will be reviewed exclusively by the HOTAC.
The primary criterion for awarding observing time to joint Herschel/XMM-Newton programmes is that both Herschel and XMM-Newton data are required to meet the scientific objectives of the proposal. It must be noted that the minimum XMM-Newton observing time is 5 ks. In addition, each observation requires 3 ks for instrument setup. In the case of Herschel observation times exceeding the minimum XMM-Newton observation time, the allocated XMM-Newton observing time cannot exceed the allocated Herschel observing time. Neither target of opportunity nor any other type of observations with a reaction time of less than 8 weeks from an unknown triggering date will be considered for this cooperative programme.
It is the proposers' responsibility to provide a full and comprehensive scientific and technical justification for the requested observing time on both facilities. Both the XMM-Newton and the Herschel observatories, will perform feasibility checks of the proposals. They each reserve the right to reject any observation determined to be unfeasible for any reason. For more information on XMM-Newton consult their website at http://xmm.esac.esa.int.
Apart from the above, for both the XMM-Newton and the Herschel observatories, the general policies and procedures currently in force for the final selection of the proposals, the allocation of observing time, the execution of the observations, and the data rights remain unchanged.