In-orbit Calibration to the Point-Spread Function of Insight-HXMT

Abstract

We make the in-orbit calibration to the point-spread functions (PSFs) of the collimators of the Hard X-ray Modulation Telescope with the scanning observation of the Crab. We construct the empirical adjustments to the theoretically calculated geometrical PSFs. The adjustments contain two parts: a rotating matrix to adjust the directional deviation of the collimators and a paraboloidal function to correct the inhomogeneity of the real PSFs. The parameters of the adjusting matrices and paraboloidal functions are determined by fitting the scanning data with lower scanning speed and smaller intervals during the calibration observations. After the PSF calibration, the systematic errors in source localization in the Galactic plane scanning survey are 0.010 deg, 0.015 deg, 0.113 deg for the Low-Energy Telescope (LE), the Medium-Energy telescope (ME) and the High-Energy telescope (HE), respectively; meanwhile, the systematic errors in source flux estimation are 1.8%, 1.6%, 2.7% for LE, ME and HE, respectively.

arXiv comment15 pages, 27 figures, accepted for publication in JHEAP

References in corpus (4)

• The Fermi Large Area Telescope On Orbit: Event Classification, Instrument Response Functions, and Calibration
• Calibration of the NuSTAR High Energy Focusing X-ray Telescope
• Reconstruction of Objects by Direct Demodulation
• The 37-month MAXI/GSC source catalog in the high Galactic-latitude sky

Cited by in corpus (5)

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• Methodology and Performance of the Two-Year Galactic Plane Scanning Survey of Insight-HXMT
• The Long-term Monitoring Results of Insight-HXMT in the First 4 Yr Galactic Plane Scanning Survey
• Insight-HXMT on-orbit thermal control status and thermal deformation impact analysis
• Insight-HXMT Measurements of the Diffuse X-ray Background