Five-year in-orbit background of Insight-HXMT

Understand

Purpose: We present the five-year in-orbit background evolution of Insight-HXMT since the launch, as well as the effects of the background model in data analysis.

• Methods: The backgrounds of the three main payloads, i.e., Low-Energy Telescope, Medium-Energy Telescope and High-Energy Telescope, are described, respectively.
• The evolution of the background over time is obtained by simply comparing the background in every year during the in-orbit operation of Insight-HXMT.
• Results: The major observational characteristics of the Insight-HXMT in-orbit background are presented, including the light curve, spectrum, geographical distribution, and long-term evolution.