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The stellar population in the Wolf-Rayet knot in NGC 5430.
Keel, W. C.
The barred spiral NGC 5430 contains an extremely luminous H II region showing very strong He II and N III Wolf-Rayet (WR) emission features. Spectrophotometry from 1200 - 7000 Å has been obtained. From these data, limits on the reddening and effective temperature of the stellar population are derived; Teff is between 25000 and 35000K. N…
Solar-type giants : new X-ray detections from EXOSAT observations.
Gondoin, P.; Mangeney, A.; Praderie, F.
The authors report new X-ray detections of HD 1671 (F5 III) and HD 12929 (K2 III). From an analysis of X-ray count rates in three broadband filters from HD 203387, they derive an estimate of its coronal temperature of T ≡ 3×106K. The data show that HD 12929 (K2 III) differs from the earlier type stars which the authors observed in the f…
EXOSAT observations of a broad absorption-line quasar : PHL 5200.
Singh, K. P.; Westergaard, N. J.; Schnopper, H. W.
Results are presented of broadband (0.05-10 keV) observations of the high-redshift quasar PHL 5200 using the EXOSAT Observatory. In observations of the 45-arcmin (FWHM) region centered on this broad-absorption-line quasar, performed with the medium-energy (ME) and low-energy (LE) experiments, X-ray emission has been detected in the 2-6 keV energy …
The ultraviolet spectrum of the peculiar emission-line star GG Carinae.
Gosset, E.; Swings, J. -P.; Brandi, E.
This paper presents the first study of the properties of the peculiar emission-line star GG Carinae in the ultraviolet wavelength domain. From IUE high resolution spectra, the authors investigate the behaviour of different velocities. From IUE low resolution data, they propose a value of the B-V excess of EB-V = 0.52±0.04 (2σ). The cont…
IUE observations of the broad continuum feature at 1400 A in the silicon and related stars.
Shore, S. N.; Brown, D. N.
The upper main sequence chemically peculiar stars have previously been studied spectrophotometrically using low resolution TD-1 spectra. These show that the broad continuum feature at 1400 Å is a useful indicator of Si anomaly. In this paper the authors extend this to IUE low resolution spectra and show that this feature is indeed well correlated …
Physical parameters for Population II stars.
Cacciari, C.; Morossi, C.; Malagnini, M. L. +1 more
The observed energy distributions from the ultraviolet to the near-infrared for a number of Population II stars have been collected from the literature (Christensen, 1978; Cacciari, 1985) and have been compared with the Kurucz (1979) model atmospheres computed for different [M/H] ratios. Effective temperatures, surface gravities and apparent angul…
Some diatomic molecules from comet P/Halley's UV spectra near spacecraft flybys
Krishna Swamy, K. S.; Wallis, Max K.
The abundances of diatomic molecules seen in the UV both give clues to the parent compounds and help unravel the gas and ion mass spectrometry. From IUE spectra of comet Halley, the authors find upper limits on SH and CS+ column densities, and estimates of probable NO, S2, and SO. In particular, judged from the 226 nm γ-band,…
High-dispersion spectroscopy of the Of/WN stars R 84 and S 61 of the Large Magellanic Cloud.
Stahl, O.; Wolf, B.; Seifert, W.
The Of/WN stars R 84 and S 61 of the LMC have been studied with high-dispersion spectroscopy in the optical and satellite-UV range. The high resolution and high S/N spectra in the optical range are particularly distinguished by strong emission lines of H, He I and [N II]. The comparison of R 84 with S 61 shows that the peculiar emission line spect…
Soft X-ray imaging observations of the 39 millisecond pulsar PSR 1951+32.
Buccheri, R.; Oegelman, H.
The authors report observations of the newly discovered 39.5 millisecond pulsar PSR 1951+32 with the soft X-ray telescope on board the EXOSAT observatory. A point-like source coincident with the position of the pulsar was observed. For a power-law model with photon index of -2, a column density of 6×1021cm-2, and a distance o…
EXOSAT observations of the magnetic binary system E 1114+182.
Pietsch, W.; Schaaf, R.; Biermann, P.
In this short note we present EXOSAT X-ray light curves of the magnetic binary system E1114+182 for two epochs. The epochs of the eclipse minima follow closely the ephemeris of Biermann et al., demonstrating that the period has not changed since the first observation with the EINSTEIN X-ray observatory in 1979. We compare the new X-ray llght curve…