SOFT X-RAY SPECTROSCOPY OF THE CYGNUS LOOP SUPERNOVA REMNANT

摘要

The Cygnus X-Ray Emission Spectroscopic Survey (CyXESS) sounding rocket payload was launched from White Sands Missile Range on 2006 November 20 and obtained a high-resolution spectrum of the Cygnus Loop supernova remnant in the soft X-ray. The novel X-ray spectrograph incorporated a wire-grid collimator feeding an array of gratings in the extreme off-plane mount that ultimately dispersed the spectrum onto gaseous electron multiplier (GEM) detectors. This instalment recorded 65 s of usable data between 43 and 49.5 A in two prominent features. The first feature near 45 A is dominated by the He-like triplet of O vii in second order with contributions from Mg x and Si ix-Si xii in first order, while the second feature near 47.5 A is first-order S ix and S x. Fits to the spectra give an equilibrium plasma at log (T) - 6.2(kT_e = 0.14 keV) and near cosmic abundances. This is consistent with previous observations, which demonstrated that the soft X-ray emission from the Cygnus Loop is dominated by interactions between the initial blast wave and the walls of a precursor-formed cavity surrounding the Cygnus Loop and that this interaction can be described using equilibrium conditions.