Search Publications
The ultraviolet absorption spectrum of the z=2.72 QSO HS 1700+6416. I. Results on heavy-element absorption systems.
Reimers, D.; Vogel, S.
We present the analysis of ultraviolet and optical spectra of the bright, high-redshift quasar HS 1700+6416. Ultraviolet observations in the range from 1150 to 3280A were obtained with the Faint Object Spectrograph (FOS) onboard the Hubble Space Telescope (HST) at a resolution of R=1300. The identification of the numerous absorption lines provides…
Infrared flux excesses from hot subdwarfs.
Ulla, A.; Thejll, P.; MacDonald, J.
Observations of 27 hot subdwarf stars and white dwarfs have been performed with an IR photometer in a search for excess fluxes in the JHK bands. 22 of the objects are observed for the first time in the infrared. In 11 of the stars a significant excess flux was found, 2 of which are new discoveries: GD 274 and GD 299. We confirm the suspicion of Mo…
The X-Ray Halo of Nova V1974 Cygni (Nova Cygni 1992) and the Nature of Interstellar Dust
Krautter, J.; Mathis, John S.; Finley, John P. +1 more
Nova V1974 Cygni (Nova Cygni 1992) was observed by ROSAT as a very bright soft X-ray source, with its point source image surrounded by an extensive halo caused by scattering from interstellar grains. We have analyzed the halo of 1992 December 6, using the standard extinction law (R = 3.1) as an additional constraint on the size distribution of the…
Relation between O VI Emission and X-Ray Intensity in Active Galactic Nuclei
Kriss, Gerard A.; Zheng, Wei; Davidsen, Arthur F.
Based on HUT observations of two Seyfert 1 galaxies and lUE and HST observations of 30 QSOs, we find a correlation between the ratio of O VI λ1034 to Lyα λ1216 and the effective power-law index between 2500 Å and 2 keV: log (O VI/Lyα) = -0.74 αOX + 0.38. From X-ray-strong to weak objects the O VI/Lyα ratio decreases by a factor of ∼8. S…
Ultraviolet Interstellar Linear Polarization. II. The Wavelength Dependence
Clayton, Geoffrey C.; Wolff, Michael J.; Allen, R. G. +1 more
We present new ultraviolet (UV) polarimetry of the well-studied interstellar line of sight toward HD 204827 obtained with the Faint Object Spectrograph on Hubble Space Telescope. HD 204827 is of great interest because the dust along this line of sight has extremely low values of both lambdamax and RV. Its far-UV extinction is…
The Emission-Line Jet in Markarian 6*
Boksenberg, A.; Capetti, A.; Sparks, W. B. +4 more
We present the results of Hubble Space Telescope (HST) and MERLIN observations of the Seyfert 1.5 galaxy Mrk 6. FOC/HST images reveal a jetlike feature in the emission line which extends ~0."5, or 250 pc, from the nucleus. The optical jet is cospatial with the southern radio jet, as revealed by a 6 cm MERLIN image matching the HST angular resoluti…
Wind Variability of B Supergiants. I. The Rapid Rotator HD 64760 (B0.5 Ib)
Massa, Derck; Prinja, Raman K.; Fullerton, Alexander W.
Stellar Photometry in the Inner Bulge of M31 Using the Hubble Space Telescope Wide Field Camera
Rich, R. M.; Mighell, K. J.
We present photometry of two fields in the M31 bulge imaged with the Hubble Space Telescope (HST) Wide-Field Camera. The nuclear field (r <40" = 150 pc) giant branch extends to I = 19.5, M_I_ = - 5 (Cousins system), a full 0.9 mag brighter than the giant-branch tips of metal-poor Galactic globular clusters and M31 halo fields. This is also ~1.5…
The underlying magnetic field direction in Ulysses observations of the southern polar heliosphere
Balogh, A.; McComas, D. J.; Forsyth, R. J. +2 more
Between April and November 1994 the Ulysses spacecraft explored heliographic latitudes above 60°S in the southern polar heliosphere and had returned to 20°S by February 1995. We have used hourly averages of the magnetic field measurements made by Ulysses to study the underlying heliospheric field direction. In contrast to data previously reported …
New Observations with the HST Goddard High Resolution Spectrograph of the Low-Redshift Lyman-Alpha Clouds in the 3C 273 Line of Sight
Rauch, Michael; Williams, Robert; Morris, Simon +2 more
We present spectra of 3C 273 between 1216 and 1250 A obtained in the (pre-COSTAR [Corrective Optics Space Telescope Axial Replacement instrument]) configuration of the GHRS, taken with the G160M grating, with a resolution of ~20 km s^-1^. The two strong Lyα lines at velocities of ~1000 and ~1600 km s^-1^ are well fitted with Voigt profiles and yie…