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Soft X-ray sources and supernova remnants in Cygnus - Rocket and Apollo-Soyuz results

1977; IOP Publishing; Volume: 215; Linguagem: Inglês

10.1086/155387

1538-4357

A. F. Davidsen, R. C. Henry, W. A. Snyder, H. Friedman, G. Fritz, S. Shulman, D. Yentis, S. Naranan,

Radiation Therapy and Dosimetry

view Abstract Citations (18) References (39) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Soft X-ray sources and supernova remnants in Cygnus: rocket and Apollo-Soyuz results. Davidsen, A. F. ; Henry, R. C. ; Snyder, W. A. ; Friedman, H. ; Fritz, G. ; Naranan, S. ; Shulman, S. ; Yentis, D. Abstract Soft X-ray observations of the Cygnus region obtained from proportional counters aboard a rocket and also on the Apollo-Soyuz mission are reported. It is found that Cyg X-6, a source whose flux in confined to the 0.5-2.0-keV band, is a long narrow filament oriented nearly perpendicular to the galactic plane. This feature has a linear dimension greater than or of the order of 150 parsecs, and its spectrum is adequately described by an exponential. Another intense soft source whose flux is also confined to the 0.5-2.0-keV band has been discovered near Gamma Cygni. This source, designed Cyg X-7, has a spectrum characterized by a temperature of 1.5 to 5 million K and a hydrogen column density of at least 10 to the 21st power per sq cm. The possible association of Cyg X-7 with the supernova remnant DR 4 is discussed. An interpretation of this object in terms of the standard adiabatic spherical-shock-wave model yields plausible values for the free paramenters. HB 21, another old supernova remnant, has not been detected as a soft X-ray source. Publication: The Astrophysical Journal Pub Date: July 1977 DOI: 10.1086/155387 Bibcode: 1977ApJ...215..541D Keywords: Spectrum Analysis; Stellar Spectra; Supernova Remnants; X Ray Sources; X Ray Spectra; Apollo Soyuz Test Project; Astronomical Maps; Histograms; Nebulae; Rocket Sounding; Stellar Evolution; Stellar Models; Astrophysics full text sources ADS | data products SIMBAD (10)