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Second COS-B catalogue of high-energy gamma-ray sources.
Bignami, G. F.; Hermsen, W.; Masnou, J. L. +11 more
A list of 25 high-energy (greater than 100 MeV) gamma-ray sources detected by COS B is presented. Only four sources are identified with well-known objects. Of the remaining sources, 20 are at low galactic latitude, and they may represent a new galactic population. Their luminosity is estimated to be in the range of (0.4-5) x 10 to the 36th ergs/se…
Ultraviolet absorption by interstellar gas at large distances from the galactic plane.
Savage, B. D.; de Boer, K. S.
Eighteen high-dispersion IUE spectra of six stars in the Large Magellanic Cloud, three stars in the Small Magellanic Cloud, and two foreground stars were analyzed. Fourteen spectra cover the wavelengths 1150-2000 A, and four cover 1900-3200 A; the velocity resolution is about 25 km/s. All the Magellanic Cloud spectra exhibit very strong interstell…
Mass loss from very luminous OB stars and the CYG superbubble.
Churchwell, E.; Abbott, D. C.; Bieging, J. H.
A description is presented of radio continuum measurements of mass loss from OB stars made at a wavelength of 6 cm with the Very Large Array (VLA). Five of the six most luminous members of the stellar association Cyg OB2 were detected. The considered investigation concentrates on the most luminous stars known in the Galaxy. The stars were selected…
Outer atmospheres of cool stars. IX. A survey of ultraviolet emission from F-K dwarfs and giants with the IUE.
Linsky, J. L.; Ayres, T. R.; Marstad, N. C.
Low-dispersion ultraviolet spectra (1150-2000 A) of a representative sample of cool stars, including dwarfs and giants of spectral types F-K, obtained with the IUE, are examined. The observation and the absolute calibration procedures are described. Correlation diagrams are constructed that compare chromospheric and transition-region emission line…
The FK COM stars.
Stencel, R. E.; Bopp, B. W.
The paper presents IUE observations of three very rapidly rotating G-K giants (v sin i = 100 km/s). The UV spectra show strong chromospheric and transition region emission lines similar to (and in excess of) the RS CVn binaries. These stars show no evidence for radial velocity variations in excess of plus or minus 3 to plus or minus 20 km/s, argui…
The type II SN 1979c in M 100 and the distance to the Virgo cluster.
Wills, B. J.; Branch, D.; Falk, S. W. +3 more
Intensity calibrated optical spectrophotometric observations of supernova 1979c in M100 were obtained between April 22, 1979 and November 24, 1979. The time development of the spectrum appears typical for type II events, except perhaps that the H-alpha feature never appears in P Cygni form. Synthetic spectra computed using a blackbody photosphere …
Mass-loss rates for 21 Wolf-rayet stars.
Willis, A. J.; Smith, L. J.; Barlow, M. J.
Mass-loss rates have been derived for 21 WR stars encompassing most subtypes in the WN and WC sequences, from measurements of their infrared free-free fluxes. The resultant mass-loss rates show a range of only a factor of 4. WC stars generally have larger mass-loss rates than WN stars, the mean rates being M(WC) = 4.1 x 10 to the -5th solar mass/y…
NGC 7714 - The prototype star-burst galactic nucleus
Sramek, R. A.; Weedman, D. W.; Feldman, F. R. +3 more
New X-ray, ultraviolet (IUE), optical, and radio (VLA) observations are presented for the bright nucleus galaxy NGC 7714. All data are explainable as resulting from intense star-formation activity in this nucleus - a star burst. The X-ray and radio luminosities are explained by supernova remnants arising from the massive stars, and approximately 1…
Mass loss rates from O stars in OB associations.
Conti, P. S.; Garmany, C. D.; Olson, G. L. +1 more
The considered investigation is concerned with an extension of an analysis of the spectra of 31 O type stars observed with the International Ultraviolet Explorer (IUE) satellite to include excited as well as resonant lines. The investigation makes use of the methods developed by Olson (1981). Most of the stars are unevolved cluster members, a grou…
Evidence for sulphur implantation in Europa's UV absorption band
Matson, D. L.; Nelson, R. M.; Lane, A. L.
The International Ultraviolet Explorer (IUE) spacecraft has obtained observations of the galilean satellites over the past 2 years which fortuitously span the periods of the Voyager encounters with the jovian system. Our IUE observing programme is designed to determine the UV spectral characteristics of the galilean satellites as a function of orb…