NuSTAR Proposals and Tools

While NuSTAR was initially approved by NASA as a 2-year Principal Investigator-led (PI-led) mission, NuSTAR now offers several opportunities for guest observers in the general scientific community to propose observations.

NuSTAR Guest Observer Program

Starting in 2014, NuSTAR solicits guest observer proposals from the general scientific community. The first cycle call for proposals was released on August 26th, 2014. Here are key dates for the current NuSTAR cycle.

DateImportant Cycle 1 Event
August 26th, 2014NuSTAR Cycle 1 Announcement of Opportunity
September 17th, 2014List of planned NuSTAR targets released
November 3rd, 2014Last day to request assistance for pointings with heavily contaminated stray light
November 25th, 2014Cycle 1 proposals due 4:30pm EST
February, 2015Approximate date of Cycle 1 peer review
April 1, 2015Approximate start of Cycle 1 guest observations

For more information, see the the guide for NuSTAR cycle 1 proposers.

Joint XMM-Newton and NuSTAR Observations

Currently NuSTAR and XMM-Newton have an arrangement which makes available joint observing time for both observatories. This resource allows observers to combine the powers of both observatories to bear on their scientific problems. This resource is extremely limited, so proposers should be sure to describe how their proposed observations exploite the unique capabilities of both observatories. Proposals for this observation time go through the XMM proposal process.

  • XMM Cycle 14 — due October 10, 2014. Approximately 1.5 Ms of joint XMM-Newton and NuSTAR observation time will be available through the XMM-Newton Cycle 14 AO. The start of observations is May, 2015.
  • XMM Cycle 13. Is now closed. Approximately 1.5 Ms of joint XMM-Newton and NuSTAR observation time was made available in the XMM-Newton Cycle 13 AO which was released on 27 August 2013. 62 such proposals were in fact submitted. Results can be found on the XMM-Newton OTAC Results page.

Joint Chandra and NuSTAR Observations

Currently NuSTAR and Chandra also have an arrangement which makes available joint observing time for both observatories. An opportunity to propose for NuSTAR observing time as part of this joint observing program is being made available through the Chandra calls for proposals.
  • Chandra Cycle 17. Expected to be similar to Cycle 16.
  • Chandra Cycle 16. Is now closed. Up to 500 ksec of NuSTAR observing time were made available through the Chandra proposal process, which closed on March 13, 2014. Results of the review can be found here.

Proposal Tools

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

NuSTAR Observatory Guide: The NuSTAR team has developed a document which describes the technical capabilities, concept of operation and key information for proposers. Download the current version NuSTAR Observatory Guide (released August 26, 2014).

Count Rate and Spectral Simulations: The standard HEASARC count rate and spectral simulations tools, WebPIMMS and WebSpec, are available for NuSTAR simulations. WebSpec was updated on March 5, 2014 to include the most recent NuSTAR responses and background files. The NuSTAR responses and background files can also be downloaded directly from the Caltech SOC web site and used to simulate spectra in spectral analysis software such as XSPEC. See Section 4.7 of the NuSTAR Observatory Guide for a detailed discussion of how to simulate NuSTAR spectra using XSPEC.

Other issues which proposers should take under consideration are:

  • Target Visibility: The NuSTAR Science Operations Center Target Visibility checker allows input of the RA and Dec coordinates of a source and finds the times when it is visible to NuSTAR subject to viewing constraints.
  • Timing: The NuSTAR Clock Correction Files keep the NuSTAR relative time (after barycentric corrections) accurate to ~2 ms and account for drifts in the NuSTAR clock caused by temperature variations, etc. New clock files will be produced as the mission continues on a ~monthly basis.
  • Stray Light: Extremely bright X-ray sources (>100 mCrab in the 3-79 keV band) within 1 to 5 degrees of a target can cause issues with elevated backgrounds due to stray light. The presence of such confusing sources is reported by the NuSTAR Science Operations Center Target Visibility checker.
  • Dead Time: NuSTAR has a triggered readout, similar to a proportional counter but unlike a CCD, so it does not suffer from pile-up effects. However, dead time becomes significant for sources above ~50 ct/s, and this must be factored into integration time estimates. Quantitative estimates of the effect of dead time on exposure estimates are included in the latest version of WebPIMMS. Further details of the effects of dead time on bright source count rates can be found in this memo (pdf).