Figure  1.  Insight-HXMT payload configuration

Figure  2.  Maintenances of the orbit

Figure  3.  Ground calibration facilities implemented for HE at hard X-rays (a) and for ME/LE at soft X-rays (b)^[12]

Figure  4.  MAD discovered during the decay phase of MAXI J1820+030^[18]

Figure  5.  HID modification by accounting for the lag corrections between different energy bands for the outburst of MAXI J1820+070^[19]

Figure  6.  Joint fits to the spectra in energy, frequency and time lag domains for the outburst of MAXI J1820+070^[20]

Figure  7.  A standard accretion disk exists during the whole outburst of SLX 1746-331^[23]

Figure  8.  A hybrid jet/corona scenario introduced to the outburst evolution of Swift J1727.8-1613^[25]

Figure  9.  Mass gap puzzle ¹

Figure  10.  BH mass estimated from an empirical correlation between disk temperature and BH mass from a BH outburst sample^[22]

Figure  11.  The BH zoo ²

Figure  12.  QPO lifetime distribution over all the March to June 2018 Insight-HXMT observations in units of cycles^[47]

Figure  13.  (a) Histogram of measured values of the phase difference between harmonics obtained using the HHT (black) and Fourier (red) methods. To show a clear peak, we repeat the data from 0 to π. (b) Reconstructed QPO waveform derived from the HHT phase-folding (black) and Fourier (red) methods^[49]

Figure  14.  Phase dependence of the seven free spectral parameters, including the temperature of the inner radius of the disk (T_in), inner radius (R_in), spectral index (Γ), electron temperature (kT_e), reflection fraction (R_f), and the normalization of relxillCp (Norm1) and xillverCp (Norm2), across the four epochs^[49]

Figure  15.  HHT phase-folded QPO waveforms of MAXI J1535-571 from Insight-HXMT/HE light curves^[51]

Figure  16.  Geometric sketch of the broad iron line emission region on the accretion disk of two specific phase intervals from the observer’s perspective. The accretion disk is divided equally into regions A, B, C, and D toroidally, with the region A being on the side closest to the line of sight of the observer^[65]

Figure  17.  Luminosity dependence of cyclotron line centroid energy with the linear energy drift of E_cyc=0.047 keV·d^–1 taken into account. The red dashed line represents the best fitting result with the broken power-law model which has three break luminosities (L₁, L₂, and L₃). These three vertical dashed lines and shaded areas are the best fitting break luminosities and corresponding uncertainties, respectively. These transitional luminosities suggest the division of the E_cyc−L_X relation into four zones (Regions I, II, III, and IV) with different types of the E_cyc–L_X correlation^[75]

Figure  18.  Unfolded spectrum of the HXMT 2018 observation with the best fit of NPEX model is shown on the left panel. The right panel shows the residues^[78]

Figure  19.  Deficit fraction versus energy during the bursts detected by HE in MAXI J1816-195^[86]

Figure  20.  Deficit fraction versus energy during the bursts detected by HE in 4 U 1608-52^[87]

Figure  21.  Deficit fraction versus energy during the bursts detected by HE in 4 U 1636-536^[88]

Figure  22.  Schematic diagram of the scanning method of a small sky area^[92]

Figure  23.  Schematic of the proposed origin model for the FRB 200428-associated X-ray burst^[106]

Figure  24.  Insight-HXMT X-ray light curves and energy spectrum fitted by the model configured in a QED scenario^[106]

Figure  25.  A scenario for the “two-stage” model of precursors for GRB221009 A^[114]