X-ray spectroscopy with the XSPECT/SODART telescopes on SRG.

The XSPECT/SODART X-ray telescopes and their associated focal plane instrumentation will be launched on board the Russian X-ray mission Spectrum Röntgen-Gamma (SRG). The authors first present the main properties of the instruments and then present simulations of some of the scientific questions which can be addressed by the observing program. XSPECT/SODART consists of two, high-throughput telescopes. In the focal plane of each one, there are high- and low energy imaging proportional counters. One telescope also has an array of silicon detectors and the other a polarimeter. An imaging, objective spectrometer consisting of three different kinds of Bragg crystals and two different multilayers is mounted in front of one of the telescopes. The broad bands of the imaging X-ray detectors collectively cover the energy rangy from 0.2 to 25 keV. The objective spectrometer samples this range around the emission and absorption features from, among others, the cosmically important ions of Fe, S, Si and O. An optical/UV monitor, co-aligned with the X-ray telescopes and consisting of three separate telescopes, will support the X-ray observations and provide aspect information.