In-orbit timing calibration of the Insight-Hard X-ray Modulation Telescope

Understand

We describe the timing system and the timing calibration results of the three payloads on-board the Insight-Hard X-ray Modulation Telescope (Insight-HXMT).

• These three payloads are the High Energy X-ray telescope (HE, 20-250 keV), the Medium Energy X-ray telescope (ME, 5-30 keV) and the low Energy X-ray telescope (LE, 1-10 keV).
• We present a method to correct the temperature-dependent period response and the long-term variation of the on-board crystal oscillator, especially for ME that does not carry a temperature-compensated crystal oscillator.
• The time of arrivals (ToAs) of the Crab pulsar are measured to evaluate the accuracy of the timing system.