Introducing a special collection of papers in the Journal of High Energy Astrophysics on the Early Results of China's 1st X-ray Astronomy Satellite: Insight-HXMT

Insight-HXMT is the first Chinese X-ray astronomical mission, launched successfully on June 15, 2017, from China's Jiuquan Satellite Launch Center. Insight-HXMT was designed to have a broad energy coverage in X-rays, from 1-250 keV, with excellent timing and adequate energy resolution at soft X-rays, and the largest effective area at hard X-rays. Here, we present a collection of papers of the Journal of High Energy Astrophysics on the Early Results of China's 1st X-ray Astronomy Satellite Insight-HXMT. These papers cover the in-orbit performance, the background model, and all calibration results, together with several first results on observations of binaries and details on the Galactic plane survey.Comment: Published to introduce a set of 20+ papers from the HXMT collaboration. Most of the referred papers can be accessed in astro-ph already, and all will be avaialble from JHEAp's webpage too, at https://www.sciencedirect.com/journal/journal-of-high-energy-astrophysics/special-issue/10B0FLKPH6

Neutron-Capture Elements in the Double-Enhanced Star HE 1305-0007: a New s- and r-Process Paradigm

The star HE 1305-0007 is a metal-poor double-enhanced star with metallicity [Fe/H] $=-2.0$, which is just at the upper limit of the metallicity for the observed double-enhanced stars. Using a parametric model, we find that almost all s-elements were made in a single neutron exposure. This star should be a member of a post-common-envelope binary. After the s-process material has experienced only one neutron exposure in the nucleosynthesis region and is dredged-up to its envelope, the AGB evolution is terminated by the onset of common-envelope evolution. Based on the high radial-velocity of HE 1305-0007, we speculate that the star could be a runaway star from a binary system, in which the AIC event has occurred and produced the r-process elements.Comment: 4 pages, 3 figures, paper accepted for publication in Chinese Physics letter