DIXE: China's Proposed High-Resolution X-ray Sky Survey Mission
Researchers have published a detailed design paper for the DIffuse X-ray Explorer (DIXE), a proposed high-resolution X-ray spectroscopic instrument intended to survey large-scale hot gas structures in the Milky Way. DIXE is designed to mount on the China Space Station, cover 0.1–10 keV energies with sub-6 eV spectral resolution, and survey roughly 72.5% of the sky over one year using a fixed zenith-pointing strategy. The instrument would advance understanding of diffuse hot gas in the Galaxy, with a novel demodulation technique enabling spatial resolution significantly finer than its wide field of view.
The DIffuse X-ray Explorer (DIXE) is a proposed X-ray astronomy payload intended for installation on the China Space Station (CSS), designed to conduct a wide-field spectroscopic survey of diffuse hot gas in the Milky Way. With a field of view of 10 degrees (half-power diameter) and an energy resolution better than 6 eV across 0.1–10 keV, DIXE would be among the most capable instruments for studying large-scale hot plasma structures in the Galaxy. The instrument would operate with a fixed zenith-pointing strategy, following the CSS orbit, and employ a sunshade to maintain at least a 25-degree angular separation from the Sun. Two sun-avoidance strategies were analyzed: one prioritizing mechanical safety and one maximizing exposure time, yielding typical one-year exposures of 26 ks and 68 ks respectively, with sky coverage of approximately 72.5% in both cases. Although the payload uses mechanical collimation rather than focusing optics, the team developed a Markov Chain Monte Carlo-based demodulation method that leverages the collimator response to achieve point-source localization accuracy of about 1 degree and extended-source spatial resolution of about 3 degrees—both substantially finer than the raw field of view. The paper, accepted for publication in Research in Astronomy and Astrophysics, presents 28 pages of instrument design, survey strategy analysis, and simulation results validating the demodulation approach.
What's missing
The paper does not specify a confirmed launch date or mission approval status for DIXE, leaving it unclear whether or how soon the instrument will actually fly.
What different sources said
- arXiv astro-phCenter
DIffuse X-ray Explorer (DIXE): Sky Survey Strategy and Collimator Response Demodulation
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