Discovery of a Fast Radiative Shock Wave in the Cygnus Loop Using the Hopkins Ultraviolet Telescope
Ferguson, Henry C.; Blair, William P.; Gull, Theodore R.; Feldman, Paul D.; Kriss, Gerard A.; Kimble, Randy A.; Davidsen, Arthur F.; Long, Knox S.; Bowers, Charles W.; Kruk, Jeffrey W.; Moos, H. Warren; Durrance, Samuel T.; Dixon, W. Van Dyke; Vancura, Olaf; Henry, Richard C.
United States
Abstract
Observations of the far-ultraviolet spectrum of a bright radiative filament on the eastern edge of the Cygnus Loop supernova remnant are described which were made through the Hopkins Ultraviolet Telescope aboard the Astro-1 Space Shuttle mission in December 1990. Observations include strong emission lines of C III 977, N III 991, and O VI 032, 1038 and many fainter lines. A comparison of this spectrum with shock model calculations indicates that the emission at this position in the Cygnus Loop is dominated by 170 km/s shock wave.