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Full-Text Articles in Astrophysics and Astronomy
Sanduleak's Star (Lmc Anonymous): Its Similarity In The Far-Ultraviolet With The Luminous Object N Carinae And Sn 1987a, A. G. Michalitsianos, Menas Kafatos, S. N. Shore
Sanduleak's Star (Lmc Anonymous): Its Similarity In The Far-Ultraviolet With The Luminous Object N Carinae And Sn 1987a, A. G. Michalitsianos, Menas Kafatos, S. N. Shore
Mathematics, Physics, and Computer Science Faculty Articles and Research
Spectra obtained in the far UV wavelength range 1200-2000 A with the International Ultraviolet Explorer (IUE) of the peculiar emission object LMC Anonymous, or Sanduleak's Star in the Large Magellanic Cloud, indicate the presence of circumstellar-high-excitation gas, which is rich in CNO processed material. Although LMC Anonymous is a field star whose nebular line-forming region can not be resolved, and whose mass may be considerably smaller than the massive-luminous galactic object η Carinae, the far-UV spectrum of LMC Anonymous closely resembles that of the S Condensation of η Carinae. The similarity between LMC Anonymous and the S Condensation is apparent …
Ultraviolet Spectrum Of The Crab Nebula, K. Davidson, T. R. Gull, S. P. Maran, T. P. Stecher, R. A. Fesen, R. A. Parise, C. A. Harvel, Menas Kafatos, V. L. Trimble
Ultraviolet Spectrum Of The Crab Nebula, K. Davidson, T. R. Gull, S. P. Maran, T. P. Stecher, R. A. Fesen, R. A. Parise, C. A. Harvel, Menas Kafatos, V. L. Trimble
Mathematics, Physics, and Computer Science Faculty Articles and Research
Data from 65 hours of observation of the Crab Nebula with the International Ultraviolet Explorer are reported, together with new ground-based spectrophotometry. We have measured the important C IV λ1549, He II λ1640, and C III] λ1908 emission line intensities and placed upper limits on other ultraviolet features for the brightest filamentary region in the nebula. We have also measured some ultraviolet continuum surface brightnesses at two places in the Crab. The emission lines imply an average ionic abundance ratio n(C^+2)/n(O^+2 ) in the range from 0.4 to 1.5 in the observed gaseous condensations. The elemental abundance ratio of carbon …
Ionization Of Carbon And Nitrogen In The Intercloud Medium, Menas Kafatos, H. Gerola, S. Hatchett, R. Mccray
Ionization Of Carbon And Nitrogen In The Intercloud Medium, Menas Kafatos, H. Gerola, S. Hatchett, R. Mccray
Mathematics, Physics, and Computer Science Faculty Articles and Research
If the intercloud medium in the solar neighborhood was suddenly ionized less than 106 years ago, the subsequent relaxation of the gas can account for the very low observed column density of C III and N III yet still leave a significant fraction ("'0.05) of ionized hydrogen and of C I in a cold (T ≈ 20° K) intercloud medium. The OAO-C Copernicus observations in the direction of X Sco are consistent with cosmic abundances and a uniform-density medium, except for C III whose predicted column density from the C m ionization zone surrounding the star is a factor ~1Q …