About HXMT
The Hard X-ray Modulation Telescope (HXMT) , named "Insight", is China’s first X-ray astronomy satellite. There are three main payloads onboard Insight-HXMT, the high energy X-ray telescope (20-250 keV, 5100 cm2), the medium energy X-ray telescope (5-30 keV, 952 cm2), and the low energy X-ray telescope (1-15 keV, 384 cm2). The main scientific objectives of Insight-HXMT are: (1) to scan the Galactic Plane to find new transient sources and to monitor the known variable sources, (2) to observe X-ray binaries to study the dynamics and emission mechanism in strong gravitational or magnetic fields, and (3) to monitor and study Gamma-Ray Bursts (GRBs) and Gravitational Wave Electromagnetic counterparts (GWEM).
The main technique parameters, the effective areas of the three X-ray telescopes and the background and sensitivities are listed here：
Table 1. The main technique parameters of Insight-HXMT telescopes
Payloads | HE | ME | LE |
Detectors | NaI(CsI) | Si-PIN | SCD |
Detector area (cm2) | ～5100 | 952 | 384 |
Energy band (keV) | 20～350 | 8～35 | 1～12 |
FOV（FWHM） | 18 collimators, including 16 FOVs of 1.1°×5.7° (one blocked), 2 FOVs of 5.7°×5.7° | 3 detector boxes, each of which contains 16 FOVs of 1°×4° (one blocked), 2 FOVs of 4°×4° | 3 detector boxes, each of which contains 21 FOVs of 1.6°×6° (one blocked), 7 FOVs of 4°×6° (one blocked), and 2 FOVs of 50～60°×2～6° |
Energy resolution (FWHM) | ≤17% (@60 keV) | 15%@20 keV | 2.5% @6 keV |
Point source resolution (20σ) | 1′ (1σ) | ||
Time resolution | 4 µs | 240 µs | 1 ms |
Fig. 1 The effective areas of the three Insight-HXMT detectors.
Fig. 2 The background spectrum of Insight-HXMT detectors.
Fig. 3 Sensitivity of pointing observations of the three Insight-HXMT detectors (100 s, 3σ). The dashed line is the estimation considering only the statistical fluctuations, and the solid line is that including systematic errors of the background (the systematic errors of HE, ME and LE are 1%, 2% and 2% of their backgrounds, respectively).
Fig. 4 The time-dependent sensitivity of pointing observations of the three Insight-HXMT detectors (3σ). The energy ranges of LE, ME and HE are 1-6 keV, 10-20 keV, and 30-100 keV, respectively. The dashed lines are the estimation considering only the statistical fluctuations, and the solid lines are that including the systematic errors of the background (the systematic errors of HE, ME and LE are 1%, 2% and 2% of their backgrounds, respectively).