Insight-HXMT observations of Swift J0243.6+6124 during its 2017-2018 outburst

The recently discovered neutron star transient Swift J0243.6+6124 has been monitored by {\it the Hard X-ray Modulation Telescope} ({\it Insight-\rm HXMT). Based on the obtained data, we investigate the broadband spectrum of the source throughout the outburst. We estimate the broadband flux of the source and search for possible cyclotron line in the broadband spectrum. No evidence of line-like features is, however, found up to $\rm 150~keV$. In the absence of any cyclotron line in its energy spectrum, we estimate the magnetic field of the source based on the observed spin evolution of the neutron star by applying two accretion torque models. In both cases, we get consistent results with $B\rm \sim 10^{13}~G$, $D\rm \sim 6~kpc$ and peak luminosity of $\rm >10^{39}~erg~s^{-1}$ which makes the source the first Galactic ultraluminous X-ray source hosting a neutron star.Comment: publishe

Overview to the Hard X-ray Modulation Telescope (Insight-HXMT) Satellite

As China's first X-ray astronomical satellite, the Hard X-ray Modulation Telescope (HXMT), which was dubbed as Insight-HXMT after the launch on June 15, 2017, is a wide-band (1-250 keV) slat-collimator-based X-ray astronomy satellite with the capability of all-sky monitoring in 0.2-3 MeV. It was designed to perform pointing, scanning and gamma-ray burst (GRB) observations and, based on the Direct Demodulation Method (DDM), the image of the scanned sky region can be reconstructed. Here we give an overview of the mission and its progresses, including payload, core sciences, ground calibration/facility, ground segment, data archive, software, in-orbit performance, calibration, background model, observations and some preliminary results.Comment: 29 pages, 40 figures, 6 tables, to appear in Sci. China-Phys. Mech. Astron. arXiv admin note: text overlap with arXiv:1910.0443

Coordination Between Tobacco Resource Development and Regional Economy

Objectives: This paper studies the relationship between the development of tobacco resources and the coordination of regional economy under the background of tobacco monopoly. Methods: This paper takes the institutional change theory as the theoretical fulcrum and the cost-benefit analysis as the main line, the correlation between regional economy and the development of tobacco industry is compared. This paper expounds the evolution history and institutional characteristics of China's tobacco monopoly system, and analyzes the changes of production, supply and marketing relationship, institutional characteristics and benefit distribution of the tobacco industry in each period. After the theoretical and empirical analysis of the costs and benefits of China's tobacco monopoly system, this paper studies the role of tobacco resource development in promoting regional economy by comparing the costs and benefits of radical and gradual reform. Results: On the premise of retaining tobacco monopoly, we should take the separation of government and enterprises and the reform of tobacco fiscal and tax system as the breakthrough. This can change the tobacco industry from administrative monopoly to economic monopoly and form tobacco trust. The linkage mechanism of "tax, profit and price" should be established to protect the interests of tobacco farmers. A tobacco auction center shall be established and a third-party tobacco rating agency shall be guided. Conclusion: The net income of the new system is higher than that of the old system. The healthy development of tobacco industry can promote regional economy.</jats:p