ﻻ يوجد ملخص باللغة العربية
We present measurements of the resolving power of a soft x-ray spectrometer consisting of 200 nm-period lightweight, alignment-insensitive critical-angle transmission (CAT) gratings and a lightweight slumped-glass Wolter-I focusing mirror pair. We measure and model contributions from source, mirrors, detector pixel size, and grating period variation to the natural line width spectrum of the Al and Mg K$_{alpha_1 alpha_2}$ doublets. Measuring up to 18$^{rm th}$ diffraction order at characteristic Al-K wavelengths we consistently obtain small broadening due to gratings corresponding to a minimum effective grating resolving power $R_g > 10,000$ with 90% confidence. Upper limits are often compatible with $R_g = infty$. Independent fitting of different diffraction orders, as well as ensemble fitting of multiple orders at multiple wavelengths, gives compatible results. Our data leads to uncertainties for the Al-K$_{alpha}$ doublet line width and line separation parameters 2-3 times smaller than values found in the literature. Data from three different gratings are mutually compatible. This demonstrates that CAT gratings perform in excess of the requirements for the Arcus Explorer mission and are suitable for next-generation space-based x-ray spectrometer designs with resolving power 5-10 times higher than the transmission grating spectrometer on the Chandra X-ray Observatory.
Several high priority subjects in astrophysics can be addressed by a state-of-the-art soft x-ray grating spectrometer (XGS). An Explorer-scale, large-area (> 1,000 cm2), high resolving power (R > 3,000) XGS is highly feasible based on Critical-Angle
The Mid-Infrared Instrument (MIRI) on-board JWST will provide imaging, coronagraphy, low-resolution spectroscopy and medium-resolution spectroscopy at unprecedented sensitivity levels in the mid-infrared wavelength range. The Medium-Resolution Spectr
High resolution spectra of the active binary Capella (G8 III + G1 III) covering the energy range 0.4-8.0 keV (1.5-30 Angstroms) show a large number of emission lines, demonstrating the performance of the HETGS. A preliminary application of plasma dia
Since the initial exploration of soft gamma-ray sky in the 60s, high-energy celestial sources have been mainly characterized through imaging, spectroscopy and timing analysis. Despite tremendous progress in the field, the radiation mechanisms at work
We present the first X-ray spectrum obtained by the Low Energy Transmission Grating Spectrometer (LETGS) aboard the Chandra X-ray Observatory. The spectrum is of Capella and covers a wavelength range of 5-175 A (2.5-0.07 keV). The measured wavelength