XRISM Frequently Asked Questions


Newly added or modified questions and answers are indicated by the *NEW* annotation.

    General

  1. Where can I get help if I have questions about XRISM data, software, archive, or other mission-related issues which are not addressed below?

    All such questions should be addressed to the HEASARC Help Desk, where you should select "XRISM" as the mailing list.

  2. How can I find out which targets either have already been or are to be observed by XRISM?

  3. Why are there objects in the Observation Log that are not listed in the PV and calibration target lists?

    Proposals

  4. Where can I find out about the XRISM Guest Observer (GO) Program?

  5. When does the Cycle 1 period begin and end? Can I submit a proposal for an observation that must take place in August, 2025?

  6. Should XRISM proposal discuss contingency plans in case the Gate Valve will have opened?

  7. If a XRISM proposal requests observations of multiple objects, or multiple pointings of an object, can it be partially accepted?

  8. Can XRISM perform TOO (target of opportunity) observations?

  9. What are the various TOO-related fields mean when proposing for TOO observations with XRISM?

  10. Do I need to take into account the ~50% observing efficiency for an exposure request? If I want to integrate on a source for 100 ks, do I need to ask for a 200 ks exposure?

    Anonymous Proposals

  11. Where do I find instructions for writing proposals for dual-anonymous review?

  12. How is the team expertise document used?

  13. How do I reference unpublished work? How do I reference proprietary results?

    Archive and Documentation

  14. When will XRISM PV data become publicly available?

Answers to XRISM Frequently Asked Questions


  1. Q: Where can I get help if I have questions about XRISM data, software, archive, or other mission-related issues?

    A: All such questions should be addressed to the HEASARC Help Desk, where you should select "XRISM" as the mailing list.


  2. Q: How can I find out which targets either have already been or are to be observed by XRISM?

    A: You can consult the list of Performance Verification (PV) targets, the list of calibration targets during the PV phase, as well as the XRISM Observation Log. The Observation Log contains all observations that have been processed.

  3. Q: Why are there objects in the Observation Log that are not listed in the PV and calibration target lists?

    A: These are most likely to be commissioning targets - celestial X-ray sources that were used for the purpose of satellite and/or instrument commissioning. The exposure times were determined by what was needed for commissioning, and the instruments may or may not be operated in the normal mode. Therefore, commissioning data may or may not be suitable for scientific use. The specific settings used for individual commissioning observations can be provided upon request.


  4. Q: Where can I find out about the XRISM Guest Observer (GO) Program?

    A: There are three parallel solicitations, depending on the institution with which the principal investigator (PI) is affiliated.

    PIs located in the US or Canada should respond to the NASA opportunity.

    PIs located in ESA member countries and cooperating states should respond to the ESA call for proposals,

    PIs located in Japan or all other countries should respond to the Japanese call for proposals,

    Please also consult the XRISM Proposers' Observatory Guide (the HTML version or the PDF version), which contains further details of the proposal process, as well as the technical capabilities of the Resolve and Xtend instruments on-board XRISM.


  5. When does the Cycle 1 period begin and end? Can I submit a proposal for an observation that must take place in August, 2025?

    A: Cycle 1 observations are expected to start during August, 2024, and continue for 1 year.

    Since there is some uncertainty in the exact start and end dates, proposals for time-critical observations in August, 2025 are allowed in Cycle 1.


  6. Q: Should XRISM proposal discuss contingency plans in case the Gate Valve will have opened?

    A: No. The Cycle 1 solitation is exclusively for the gate-valve closed configuration of XRISM/Resolve.


  7. Q: If a XRISM proposal requests observations of multiple objects, or multiple pointings of an object, can it be partially accepted?

    A: Yes, if, in the opinion of the reviewers, partial acceptance makes sense.

    If this is also acceptable in the opinion of the propsing team, we recommend that the targets be listed in the order of priority.


  8. Q: Can XRISM perform TOO (target of opportunity) observations?

    A. Yes, and there are two ways to request them. TOO observations of unpredictable events in known targets can be requested through the regular proposal process. However, generic TOO proposals - for unpredictable events in a class of objects, whose identities are not known in advance (e.g., outburst of a hitherto unknown X-ray transient) - are not solicited in Cycle 1. In addition, TOO targets cannot be mixed with non-TOO targets within a single proposal.

    In addition, it will be possible to submit a real-time request for TOO observations, once an unpredictable event is detected. During the PV phase, this opportunity is open only to the XRISM team members; in the GO phase of the mission, a mechanism to submit real-time TOO and other drector's discretionary time (DDT) observation will be opened to the community at large,

    Once triggered, the anticipated response time for TOO observation is 48 to 72 hours.

    See notes on TOO proposals for more.


  9. Q: What are the various TOO-related fields mean when proposing for TOO observations with XRISM?

    A. For the purpose of time allocation, we use probability-weighted exposure times for TOO proposals, the estimate for which must be provided by the proposers (the basis for the estimate should be provided in the proposal text). For XRISM, we request the proposal-wide probability-weighted exposure time on the general form. Also, the general form should indicate the estimated probability that at least some of the proposed observations can be triggered. See notes on TOO proposals for more. In addition, the triggering criterion must be explicitly specified. This can be done in the Remarks boxes either individually in the target forms or collectively in the general form.


  10. Q: Do I need to take into account the ~50% observing efficiency for an exposure request? If I want to integrate on a source for 100 ks, do I need to ask for a 200 ks exposure?

    A: No. POG Section 2.1 states "The overall observing efficiency of the satellite is expected to be about 45%. Proposals should specify the desired good on-source exposure but without accounting for instrumental dead times due to high count rates, if relevant." Please also take a look at the ARK help for XRISM RPS forms of the Total Observation Time entry.


  11. Q: Where do I find instructions for writing proposals for dual-anonymous review?

    A: The NASA solicitation of XRISM observing time will be evaluated through dual-anonymous peer review. This means that proposals should eliminate language that identifies the proposers or institution. For more information see the Guide to XRISM Proposers and in particular the Guidelines for Anonymous Proposals.


  12. Q: How is the team expertise document used?

    A: PIs are required to provide an non-anonymized "Expertise and Resources" PDF file (typically one page, up to 3 pages are allowed), as a second upload (after the anonymized scientific justifcation) through ARK. A LaTeX template and a Word template are available.

    This document will be distributed to the review panel after all proposals have been reviewed and rated, only for programs which are in the selectable range. This is to allow the reviewers to assess the team capabilities required to execute a given proposed science investigation. If there are clear, compelling deficiencies in the expertise required to see through the goals of the proposal, the panel may decide to flag the submission accordingly, and provide a detailed justification in its comments to NASA. This review may not be used to change the rating of the proposals.


  13. Q: How do I reference unpublished work? How do I reference proprietary results?

    A: References to published work are encouraged, including work citable by a Digital Object Identifier (DOI).

    Unpublished work that is based on public data sets or public software can be referenced as work "by the proposal team," without identifying the PI or Co-Is by name.

    It may be necessary to cite exclusive access datasets or non-public software that may reveal (or strongly imply) the investigators on the proposal. It is suggested proposers use language such as "obtained in private communication" or "from private consultation" when referring to such potentially revealing work, again without identifying anyone by name.


  14. Q: When will XRISM PV data become publicly available?

    A: The bulk of the PV data will be made public one year after the conclusion of the PV phase of the mission, i.e., August, 2025.

    In addition, we are making some Early Release data public. The released files include X-ray images or spectra obtained and reduced during the commissioning or calibration operations of the Resolve and Xtend instruments aboard XRISM. Note that the event files are not provided. Moreover, these data were extracted assuming the current, still preliminary, calibration. While the calibration is advanced enough to demonstrate the data quality, reliable scientific results cannot be derived from these data products,


If you have questions regarding XRISM, concerning, e.g., calibration, analysis, proposing, ToOs, or coordination, please use HEASARC's Feedback form , or click the "HELP" icon to the left.