Insight-HXMT, the first X-ray astronomical satellite in China, aims to reveal new sources in the Galaxy and to study fundamental physics of X-ray binaries from 1\,keV to 250\,keV. It has three collimated telescopes, the High Energy X-ray telescope (HE), the Medium Energy X-ray telescope (ME) and the Low Energy X-ray telescope (LE). Before the launch, in-orbit backgrounds of these three telescopes had been estimated through Geant4 simulation, in order to investigate the instrument performance and the achievement of scientific goals. In this work, these simulated backgrounds are compared with in-orbit observations. Good agreement is shown for all three telescopes. For HE, 1) the deviation of the simulated background rate after two years of operation in space is $\sim5\%$ from the observation; 2) the total background spectrum and the relative abundance of the $\sim$67\,keV line show long-term increases both in simulations and observations. For ME, 1) the deviation of simulated background rate is within $\sim15\%$ from the observation, and 2) there are no obvious long-term increase features in the background spectra of simulations and observations. For LE, the background level given by simulations is also consistent with observations. The consistencies of these comparisons validate that the Insight-HXMT mass model, i.e. space environment components and models adopted, physics processes selected and detector constructions built, is reasonable. However, the line features at $\sim$7.5\,keV and 8.0\,keV, which are obvious in the observed spectra of LE, are not evident in simulations. This might result from uncertainties in the LE constructions.
In-Orbit GRB Identification Using LLM-based model for the CXPD CubeSat
School of Physical Science, University of Chinese Academy of Sciences（中国科学院大学物理科学学院）；School of Astronomy and Space Sciences, University of Chinese Academy of Sciences（中国科学院大学天文与空间科学学院）；National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；Guangxi Key Laboratory for Relativistic Astrophysics, School of Physical Science and Technology, Guangxi University（广西大学物理科学与技术学院相对论天体物理重点实验室）；Zhejiang Lab（之江实验室）；New Cornerstone Science Laboratory, National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台新基石科学实验室）
The XGIS instrument on-board THESEUS: Monte Carlo simulations for response, background, and sensitivity
瞬态高能天空和早期宇宙勘测者（THESEUS）飞行任务中的X和伽马成像光谱仪仪器的响应是欧空局在宇宙视野M5发射机会的框架内选定的评估阶段，已经用基于Monte Carlo Geant-4的软件进行了广泛的建模。本文描述了THESEUS计划中预计的近地轨道背景源（如漫射光子背景、宇宙射线粒子数、地球辐射），并给出了模拟的星上背景环境及其对仪器性能的影响。
Target Detection Framework for Lobster Eye X-Ray Telescopes with Machine Learning Algorithms
College of Physics and Optoelectronic, Taiyuan University of Technology（太原理工大学物理与光电工程学院）；Peng Cheng Lab（鹏城实验室）；National Astronomical Observatories（国家天文台）
