The Reflection Grating Spectrometer on board XMM-Newton

TLDR

XMM‑Newton carries two identical Reflection Grating Spectrometers that provide high‑resolution (up to R≈500) soft‑X‑ray spectroscopy (6–38 Å, 2.1–0.3 keV) with a peak effective area of ~140 cm² at 15 Å. This paper fully describes the RGS design and operational modes. The RGS is optimized to detect K‑shell lines of C, N, O, Ne, Mg, Si and L‑shell Fe, and its design and in‑orbit performance—including line spread function, wavelength calibration, effective area, and background—are reviewed.

Abstract

The ESA X-ray Multi Mirror mission, XMM-Newton, carries two identical Reflection Grating Spectrometers (RGS) behind two of its three nested sets of Wolter I type mirrors. The instrument allows high-resolution ( to 500) measurements in the soft X-ray range (6 to 38 Åor 2.1 to 0.3 keV) with a maximum effective area of about 140 cm2 at 15 Å. Its design is optimized for the detection of the K-shell transitions of carbon, nitrogen, oxygen, neon, magnesium, and silicon, as well as the L shell transitions of iron. The present paper gives a full description of the design of the RGS and its operational modes. We also review details of the calibrations and in-orbit performance including the line spread function, the wavelength calibration, the effective area, and the instrumental background.