Diffuse X-ray Explorer: a high-resolution X-ray spectroscopic sky surveyor on the China Space Station

TL;DR

DIXE is a proposed high-resolution X-ray spectroscopic surveyor on the China Space Station aimed at studying hot baryons in the Milky Way through large sky surveys using superconducting microcalorimeters.

Contribution

It introduces a novel high-resolution X-ray spectroscopic instrument design for sky surveys, leveraging the CSS's orbital motion and advanced TES technology.

Findings

Preliminary design of DIXE presented.

Key components include microcalorimeter array and cryogenic cooling system.

Expected to complement eROSITA's imaging data.

Abstract

DIffuse X-ray Explorer (DIXE) is a proposed high-resolution X-ray spectroscopic sky surveyor on the China Space Station (CSS). DIXE will focus on studying hot baryons in the Milky Way. Galactic hot baryons like the X-ray emitting Milky Way halo and eROSITA bubbles are best observed in the sky survey mode with a large field of view. DIXE will take advantage of the orbital motion of the CSS to scan a large fraction of the sky. High-resolution X-ray spectroscopy, enabled by superconducting microcalorimeters based on the transition-edge sensor (TES) technology, will probe the physical properties (e.g., temperature, density, elemental abundances, kinematics) of the Galactic hot baryons. This will complement the high-resolution imaging data obtained with the eROSITA mission. Here we present the preliminary design of DIXE. The payload consists mainly of a detector assembly and a cryogenic cooling system. The key components of the detector assembly are a microcalorimeter array and frequency-domain multiplexing readout electronics. To provide a working temperature for the detector assembly, the cooling system consists of an adiabatic demagnetization refrigerator and a mechanical cryocooler system.