Search Publications
LSS 4300 : a hot counterpart of upsilon Sagittarii and KS Persei ?
Drilling, J. S.; Schoenberner, D.
A number of recent observations indicate that the star LSS 4300 (HDE 320156) is a high-temperature analog of the hydrogen-deficient binaries Upsilon Sgr and KS Per. A preliminary model-atmosphere analysis based on high dispersion spectra obtained at Kitt Peak and Cerro Tololo yields Teff = 14,400 K, log (g) = 1.4, n(H)/n(He) = 0.003, and n(N)/n(C)…
Line profiles from supernovae.
Fransson, C.
The location and mechanism of 120-200-nm emissions from supernovae are investigated theoretically, and the results are applied to IUE observations of SN 1979c reported by Panagia et al. (1980). Analytical expressions are obtained for line profiles originating in the expanding photosphere behind the shock wave (using the two-level approximation) an…
IUE high resolution spectrophotometry of H LY alpha emission from the local interstellar medium
Bowyer, S.; Clarke, J. T.; Fahr, H. J. +1 more
IUE high dispersion spectra of resonantly scattered solar Ly alpha emission from H moving into the solar system with the local interstellar wind are reported which are based on observations conducted in April 1981 and April 1983. A heliocentric velocity of -29 + or - 5 km/s has been observed from the ISW component along with a surface brightness w…
Images in the rocket ultraviolet : photometry of M 101.
Bohlin, R. C.; Stecher, T. P.; Hill, J. K.
Three ultraviolet images of the Sc I galaxy M101 (NGC 5457) were obtained by a rocket-borne telescope, using a microchannel plate image intensifier coupled to IIa-O film, giving an effective wavelength of 2250 Å, a bandpass of 970 Å, and about 10arcsec resolution over an 80arcmin field. Extreme Population I dominates in the UV in the form of OB/H …
IUE spectrophotometry of the DA4 primary in the short-period white dwarf red dwarf spectroscopic binary Case 1.
Sion, E. M.; Wesemael, F.; Guinan, E. F.
Low-resolution ultraviolet International Ultraviolet Explorer spectra of the DA white dwarf Case 1 are presented. The spectra show the presence of the 1400 A feature, already discovered in several other DA stars, and of a shallower trough in the 1550-1700 A range. A model atmosphere analysis of the ultraviolet energy distribution of the Ly-alpha r…
X-ray and UV observations of two radio-bright quasars.
Elvis, M.; Fabbiano, G.
The two quasars PKS 10004 + 13 (4C 13.41, V about equal to 15.2, z = 0.140) and PKS 0637 - 75 (V = 15.75, z = 0.651) were observed in December 1980 with IUE. Both were detected in the short-wavelength region. The present X-ray upper limit for PKS 1004 + 13 gives the lowest L-x/L-opt measured in quasars. PKS 0637 - 75 was observed nearly simultaneo…
Multigrequency spectral behavior of the BL Lacertae objects OI 90.4 and 3C 66A.
Bruhweiler, F. C.; Miller, H. R.; Worrall, D. M. +4 more
Single-epoch multifrequency data for the BL Lac objects OI 90.4 and 3C 66A, spanning radio through ultraviolet wavelengths, are presented, as well as other measurements relevant to intensity and spectral-shape variability. Both BL Lac objects exhibit spectral curvature in the infrared-to-ultraviolet region, a properity that is inferred to be usual…
Ultraviolet spectra of planetary nebulae - X. Physical conditions in the compact planetary nebula SW ST 1.
Cohen, M.; Flower, D. R.; Goharji, A.
The authors analyse photoelectric visual and ultraviolet observations of the compact planetary nebula Sw St 1. The electron density, determined from the C III λλ1907/1909 line ratio, is Ne = (1.1±0.1)×105cm-3, consistent with the high emission measure and high critical frequency determined from observations of the …
Spectrophotometry of southern Herbig-Haro and related objects.
Krautter, J.; Eichendorf, W.; Reipurth, B.
In this note, spectrophotometry is presented for four Herbig-Haro or Herbig-Haro-like objects. HH 55 is observed for the first time, and has a typical HH spectrum but with weak forbidden N II lines and indication of a weak continuum. M 16 HH 1 shows an extreme weakness of the forbidden OI lines which sets it apart from all known HH objects. Th 28 …
On the dispersion in brightness of far-ultraviolet emission lines of cool giant stars.
Simon, T.
Low-resolution spectra have been obtained with the short-wavelength camera of IUE for late-type giant stars of spectral type F5 III-G8 III. These stars are believed to be in their first crossing of the H-R diagram, as inferred from their location along the blue edge of the Hertzsprung gap or their high abundance of lithium. From the earliest spect…