IXPE Proposals and Tools


General Observer Program

Previous Cycles


IXPE Cycle 1 Recommended Targets

The IXPE mission is pleased to announce that the proposal selection process for GO Cycle 1 is complete, and observations will begin in Febrauary 2024. Documents listing selected proposals and approved targets have been released.

1. IXPE General Observer (GO) Program

IXPE solicits general observer proposals from the general scientific community. Proposals are solicited via NASA's ROSES grant solicitation process. The proposal process is divided into two phases. A Phase 1 proposal is submitted to NASA HEASARC's ARK system, containing detailed target selection forms and a concise science justification. Proposals may come from both US and non-US researchers. Phase 1 proposals are evaluated by peer review panels. Data from approved IXPE GO observations are public by default, however, GO proposal PIs can request a six month exclusive-use period, subject to peer review approval.

NASA also provides grant funding to support certain selected proposals. Selected proposals will receive a notification letter with more details and an invitation to submit a Phase 2 (budget) proposal. Phase 2 proposals are submitted to NASA's NSPIRES system. In addition, there are reporting requirements for proposals with budget awards.

DateImportant Cycle 1 Event
February 14, 2023NASA Research Announcement IXPE General Observer - Cycle 1
June 2023Cycle 1 phase 1 proposal submissions open
September 18th 2023Non mandatory NOIs due through NSPIRES
October 18th (Wednesday), 2023 Cycle 1 phase 1 proposals due through ARK/RPS
February 2024Cycle 1 observations begin
March 8th 2024Cycle 1 Phase 2 proposals due through NSPIRES

2. Observatory Guide and Proposal Tools

The IXPE project has developed tools and documentation to help potential proposers.

The IXPE team has developed a document which describes the technical capabilities, concept of operation and key information for proposers. Download the current version IXPE Observatory Guide (2.2 MB pdf file) (released June 2022).

Additionally, the following tools may be useful in preparing IXPE proposals:

  • Count Rate and Minimum Detectable Polarization: The standard HEASARC WebPIMMS tool is available for IXPE simulations.

  • Visibility: The standard HEASARC Viewing tool can be used to determine target visibilities for IXPE.

  • User contributed software: In addition to the standard HEASoft FTOOLs the user-contributed software package ixpeobssim can be also be used to produce realistic simulated observations for IXPE proposals. See here for more details.

  • 3. Grant information

    Phase 2 (Budget) Proposals

    PI's whose Phase-1 proposals were accepted and are eligible for funding will be invited to submit a Phase-2 (cost) proposal through NSPIRES.

    NASA and the federal government have specific requirements for the reporting of results obtained by the recipients of grant funds. The document Grant and Cooperative Agreement Handbook details much of this information.

    No-Cost Extensions

    The information about No-Cost Extensions (NCE) on a NASA grant administered by the NASA Shared Services Center (NSSC) can be found here (see Section 7.8). To request a No-Cost Extension, please complete the electronic form. The first NCE is usually approved. Additional extensions will require significant justification.

    Closeout/Final Report

    IXPE GOs receiving NASA grants are required to file a Summary of Research Report detailing their supported activities along with necessary documentation within 90 days of the conclusion of the grant period. The report should list the objectives of the research and the achieved goals, including the dissemination of the results (i.e., papers published on the subject). The report should be submitted by the budget Principal Investigator, and should include the activities of any subgrant recipients. If the proposed research was not feasible, explain why not. Be sure to include the proposal number for the original science proposal. This is the five-digit number assigned when the proposal was submitted to RPS.

    A template for this report can be found here. The "NASA proposal number" that is requested at the top right of the form is that of the original science proposal. This is the five-digit number assigned by NASA. The "Grant Number" (formerly a NAG number), requested just below the "NASA proposal number" on the form, can be found in the grant package.

    The final report should be e-mailed to the Technical Officer for IXPE GO grants at ixpe_grants@bigbang.gsfc.nasa.gov. It should also be e-mailed to the Grant Officer of NASA's Shared Services Center (NSSC) at NSSC-CloseOut@mail.nasa.gov, in addition to any other reports requested by NSSC.

    4. Unanticipated IXPE Target of Opportunity (ToO) Observations:

    Unanticipated ToO or Directors Discretionary Time (DDT) requests for events or sources that could not have been predicted or proposed for in GO programs, can be made using the IXPE ToO request form on the IXPE project website at MSFC. The decision on whether to perform an unsolicited ToO or DDT observation will be made by the IXPE Principal Investigator or an official designee. Such ToO requests are unfunded and do not have an exclusive-use period.

    IXPE Helpdesk

    If you have any questions concerning IXPE or the IXPE GO program, please use the Feedback form

    Please be sure to select "IXPE" as the mailing list so that your question can be routed to the correct helpdesk promptly.