Search Publications
Complex Mg II Absorption in the Outer Disk of M61
Bowen, David V.; Pettini, Max; Blades, J. Chris
The increasing availability of high-quality spectra of QSO absorption-line systems at resolutions of only a few kilometers per second is expected to facilitate the translation of the kinematics of components comprising the lines into the spatial distribution of gas around an absorbing galaxy. In this Letter we present Hubble Space Telescope (HST) …
The IUE Spectrum of the Unusual Wolf-Rayet PG 1159--Type Star Sanduleak 3
Feibelman, Walter A.
Archival and new lUE spectra are resented for the very hot WC 0 vi star Sand 3 (= WR 72), covering the wavelength range 1170-3200 Å. Emission-line fluxes were measured and terminal wind velocities were determined from the P Cyg N V and C iv doublets. Sand 3 is known to show some of the highest excitation stellar lines in the optical region, and th…
The IUE Spectrum of the Planetary Nebula NGC 6905
Feibelman, Walter A.
We present results from new lUE high-dispersion and archival low-dispersion spectra of NGC 6905. Ultraviolet emission lines of O VIII and possibly O VII are detected for the first time in NGC 6905. High-excitation lines of C IV, C V, O VI, [Mg V], [Ne III], [Ne IV], [Ne V], [Ar IV], and [Ar V] are also observed. Electron densities and terminal win…
Hubble Space Telescope Narrowband Imaging of the Planetary Nebula SMP 83/WS 35/N66
Vassiliadis, E.
LMC-SMP83 is a planetary nebula in the Large Magellanic Cloud whose central star is recently reported by Pena et al. to show decreases in temperature and luminosity of at least 50% over a time span of seven years. Serendipitously, this object is observed with the Planetary and Faint Object Cameras onboard the Hubble Space Telescope between 1991 Ju…
Pulsations in the Ultraviolet and X-Ray Spectra of VELA X-1
Nagase, Fumiaki; McCray, Richard; Boroson, Bram +1 more
In simultaneous observations with the Faint Object Spectrograph aboard the Hubble Space Telescope and the large-area counters aboard Ginga, we obtained time-resolved ultraviolet and X-ray spectra of the X-ray binary HD 77581/4U 0900-40 (Vela X-1) during inferior conjunction of the X-ray source. We detected pulsations at the 283.33 s X-ray pulse pe…
IUE Observations of Young Clusters in the Large Magellanic Cloud
Hodge, Paul W.; Wilcots, Eric M.; King, Nichole
We present the results of a study of the ultraviolet properties of the most massive stars in two young clusters in the Large Magellanic Cloud (LMC), NGC 1770 and NGC 2014. Although there is some variation across each cluster, we find that the properties of the interstellar extinction toward these clusters are consistent with those previously deriv…
Temperature Distributions of Accretion Disks in Active Galactic Nuclei
Zhou, You-Yuan; Wang, Jian-Min
We present a simple analytical method to determine the temperature distribution of optically thick accretion disks on the basis of the spectral shape of the big blue bump in an active galactic nucleus (AGN). The method is general and does not require the disk to be Keplerian, stationary, or even conservative (without mass loss). Eight AGNs observe…
Plaskett's Star (HD 47129): Still More Curious
Bagnuolo, William G., Jr.; Barry, Donald J.
The properties of the components of Plaskett's Star (HD 47129) have been the subject of a continuing controversy for over seven decades. In a recent paper, Bagnuolo, Gies, & Wiggs analyzed a set of 17 UV spectra of this object from IUE archives. A tomography algorithm was used to produce the individual spectra of the two components. The physic…
The Polarization of X-Ray Binaries in the Ultraviolet. I. Cygnus XR-1, 4U 0900-40, and 4U 1700-37
Boyd, Patricia T.; van Citters, G. W.; Taylor, M. +5 more
Cyg XR-1, 4U 0900 - 40, and 4U 1700 - 37 were monitored polarimetrically and photometrically in the ultraviolet (UV) with the High Speed Photometer (HSP) on the Hubble Space Telescope (HST) at 6-10 different phases during a single binary orbit. Polarimetric observations were obtained in a bandpass centered at 2770 Å; 4U 0900-40 was also monitored …
ROSAT PSPC Observations of the Intermediate Polar TV Columbae
Raymond, J. C.; Primini, F.; Vrtilek, S. D. +1 more
The intermediate polar TV Columbae was observed for 8640s with the ROSAT PSPC. The best-fitting model to the 0.1-2.0 keV spectrum combines a power law with photon index α = 0.82 and a 54 eV blackbody, both observed through a column density of 4.6 x 1020 cm-2. No evidence is seen for line emission from the Fe L-shell complex. …