Why Legacy Surveys?

Two of NuSTAR’s key mission goals were to conduct deep, wide-field surveys in both Galactic and extragalactic fields. While a significant amount of time had been invested in these surveys during the primary mission, it was clear that maximizing the legacy of the NuSTAR required significantly extending both of these surveys.

NuSTAR Galactic and Extragalactic Legacy Surveys were selected based on community input and performed in the mission extensions from 2015 to 2019. These programs are now complete. The legacy survey data was immediately made public, and source catalogs and spectra will be released as soon as they have been processed.

 

Remaining Legacy Surveys

NuSTAR will continue observing targets from a sample of AGN selected from the Swift BAT hard X-ray survey. Each target will be observed to obtain a 20 ks exposure by NuSTAR and 7 ks by Swift-XRT. On average 6 sources are planned to be observed each month. A higher priority is assigned to the subset of these targets that are scheduled for Chandra observations as part of the Chandra Cool Attitude Target program starting in January 2019.

NuSTAR will also continue to support the multiwavelength campaign of coordinated observations of the Galactic center with the Event Horizon Telescope (EHT). This offeres a unique opportunity to cross-correlate the hard X-ray variability and spectral analysis with structural changes observed by the EHT and aims to probe the innermost regions of accretion flow around a supermassive black hole. 

Observations have been approved for the 2020 EHT campaign coordinated with Chandra proposal 21700401 (PI Haggard).

Data from these legacy survey observations have no exclusive use period, and are executed by the NuSTAR science team as a service to the community. 

• General Observer (GO) proposal and target conflicts with Swift-BAT AGN Targets 
  Observations of targets accepted through the NuSTAR GO Call for Proposals will take precedence over the Swift-BAT AGN legacy program. The status of legacy survey target observations can be found in HEASARC's numaster table by selecting "EGS" for the obs_type keyword.
• Observations of GO targets approved through the various joint programs with other missions will also take precedence over Swift-BAT AGN targets. See the "For Proposers" webpage for more details about joint observing programs.

 

Last updated: 2019-09-24

---