Preliminary results from the diffuse x-ray spectrometer

摘要

Abstract: The Diffuse X-Ray Spectrometer (DXS) experiment wasflown as an attached Shuttle payload in January 1993aboard the STS-54 mission of the Space ShuttleEndeavor. DXS consists of two large- area Bragg crystalX-ray spectrometers that cover the 44 - 83 angstromswavelength range, and are designed to measure thespectrum of the low energy (0.15 $LS E $LS 0.28 keV)diffuse X- ray background with roughly 10 eV energyresolution and 15$DGR angular resolution. These diffuseX-rays are thought to be generated by a very hot(10$+6$/ K) component of the interstellar medium thatoccupies a large fraction of the interstellar volumenear the Sun. Astrophysical plasmas near 10$+6$/ K arerich in emission lines, and the relative strengths ofthese lines, besides providing information about thephysical conditions of the emitting gas, also provideinformation about its composition, history and heatingmechanisms. We present preliminary spectra of the softX-ray background in the energy range 0.15 $LS E $LS0.28 keV. Spectra were obtained from along a greatcircle that lies 0$DGR - 10$DGR north of the galacticplane between galactic longitudes 150$DGR and 300$DGR@.The spectra show emission lines, the first directevidence that the soft X-ray background arises in hotinterstellar gas. The spectra seen along the greatcircle in different resolution elements are differentfrom one another. We fitted a range of models to thesespectra, and present preliminary results of thesefits.!8