21 August 2013 Dear Colleague, NASA is pleased to call to the attention of members of the U.S. scientific community the release by the European Space Agency (ESA) of the Announcement of Opportunity (AO), "XMM-Newton Call for Observing Proposals", soliciting Guest Observing proposals for the 13th cycle (AO-13) observing program for ESA's X-ray Multi-Mirror Mission (XMM-Newton). The subject Announcement solicits proposals for observations to be performed during a 12-month period commencing in May 2014. Due to the nature of the NASA-ESA bilateral agreement, only proposals from scientists affiliated with U.S. institutions are solicited by this Letter; others are advised to contact ESA directly. U.S. scientists may propose either as Principal Investigators or as Co-Investigators on proposals with either U.S. or non-U.S. (foreign PI proposals) PIs. The AO may be accessed directly from ESA at the following address: http://xmm.esac.esa.int/external/xmm_science/AO13/index.shtml The XMM-Newton Guest Observer Facility (GOF) at the Goddard Space Flight Center (GSFC) is the support center for XMM-Newton activities in the U.S. Information of interest to U.S. observers, as well as general project information, can be found at the following address: http://xmm.gsfc.nasa.gov/ A detailed description of the mission, including instrument capabilities and additional information pertaining to the proposal preparation and submission procedures, is also available via links from the XMM-Newton home page at that address. (General questions concerning XMM-Newton and participation by U.S. investigators should be addressed to xmmhelp@athena.gsfc.nasa.gov.) ESA will be responsible for conducting a peer review of all submitted proposals, including those from U.S. investigators, and determining the associated time allocation. Current plans call for ESA to notify proposers and NASA of the results of the peer review in mid-December 2013. Subject to the outcome of the 2014 Senior Review of Operating Missions, NASA currently expects to allocate approximately $960K in Fiscal Year 2015 for a Guest Observer (GO) program to support the analysis, interpretation and publication of data obtained by U.S. proposers who are granted Open Time observing on XMM-Newton under AO-13. This level is comparable to the amount available for the support of US GOs for AO-10 through AO-12. In light of the existing budgetary constraints, it is anticipated that only US PIs with Category "A" proposals will be invited to apply for support from the US XMM-Newton GO program for AO-13. As for AO-12, U.S. PIs with lower ranked Category B proposals and U.S. Co-Is on foreign-PI Category A and B science proposals will be permitted to apply for funding from the Astrophysics Data Analysis Program (ADAP). Pending the results of the ESA selection of observing proposals submitted to AO-13 and of the 2014 NASA Senior Review (tentatively planned for March 2014), NASA will issue an update to this DCL to inform US proposers of any changes to the above. For additional technical or programmatic information regarding U.S. participation in the XMM-Newton mission, please contact: Technical Information: Dr. Steve Snowden Goddard Space Flight Center Code 662 Greenbelt, MD 20771 Tel: (301) 286-8100 Fax: (301) 286-1684 Steven.L.Snowden@nasa.gov Programmatic Information: Dr. Louis Kaluzienski Astrophysics Division Science Mission Directorate Mail Suite: 3W39 NASA Headquarters 300 E Street, SW Washington, DC 20546-0001 Tel: (202) 358-0365 Louis.J.Kaluzienski@nasa.gov Sincerely, Dr. L. J. Kaluzienski U.S. XMM-Newton Program Scientist