2021 Effective Area calibration of the Nuclear Spectroscopic Telescope ARray (NuSTAR)
Abstract
We present here the updated calibration of The Nuclear Spectroscopic Telescope ARray NuSTAR, which was performed using data on the Crab accumulated over the last 9 years in orbit. The basis for this new calibration contains over 250ks of focused Crab (imaged through the optics) and over 500ks of stray-light Crab (not imaged through optics). We measured an epoch averaged Crab spectrum of the stray-light Crab data and define a canonical Crab spectrum of Γ = 2.103 ± 0.001 and N = 9.69 ± 0.02 keV⁻¹ cm⁻² s⁻¹ at 1 keV, which we use as our calibration standard. The new calibration, released in the CALDB update 20211020, provides significant updates to: 1) the detector absorption component, 2) the detector response function, and 3) the effective area vignetting function. The calibration improves agreement between FPMA and FPMB across detectors with a standard deviation of 1.7% for repeat observations between off-axis angles of 1-4 arcmin, and the measured flux has increased by 5-15%, with 5% below 1 arcmin off-axis angle, 10% between 1-2 arcmin, and 15 above 4arcmin.
Additional Information
This work was supported under NASA Contract No. NNG08FD60C, and made use of data from the NuSTAR mission, a project led by the California Institute of Technology, managed by the Jet Propulsion Laboratory, and funded by the National Aeronautics and Space Administration. This research has made use of the NuSTAR Data Analysis Software (NuSTARDAS) jointly developed by the ASI Space Science Data Center (SSDC, Italy) and the California Institute of Technology (USA). This material is based upon work supported by NASA under award number 80GSFC21M0002. We thank Murray Brightman, Renee Ludlam, Guglielmo Mastroserio, and Riley Connors for performing the case study re-analyses in §7.2.Attached Files
Submitted - 2110.11522.pdf
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Additional details
- Alternative title
- Effective Area calibration of the Nuclear Spectroscopic Telescope ARray (NuSTAR)
- Eprint ID
- 112872
- Resolver ID
- CaltechAUTHORS:20220113-182222694
- NASA
- NNG08FD60C
- NASA
- 80GSFC21M0002
- Created
-
2022-01-13Created from EPrint's datestamp field
- Updated
-
2023-06-02Created from EPrint's last_modified field
- Caltech groups
- Space Radiation Laboratory, NuSTAR