Search Publications
The IUE Spectrum of the "O VI Sequence" Planetary Nebula He 2-55
Feibelman, Walter A.
The first IUE observations of the "O VI Sequence" planetary nebula He 2-55 are reported. The ultraviolet spectrum is dominated by strong emission lines of O V, C IV, He II, and C III], plus a number of weaker ions for which emission line fluxes were measured. N V lambda 1240 and C IV lambda 1549 show P Cygni profiles. The stellar terminal wind vel…
A Search for Stellar Flares in Gamma-Ray Bursts Observed by BATSE and ULYSSES
Hurley, K.; Fishman, G. J.; Kouveliotou, C. +2 more
We have searched for gamma-ray bursts during stellar flares using Ulysses and BATSE/CGRO data and for a correlation between flare star positions and burst positions. More than 3000 stellar flares have been identified optically, but neither BATSE nor Ulysses observed any gamma-ray bursts which could be attributed to them. Using the BATSE trigger th…
Radiation Hydrodynamic Models of Eclipsing Low-Mass X-Ray Binaries
McKee, Christopher F.; Murray, Stephen D.; Woods, D. Tod +2 more
We present the results of self-consistent two-dimensional radiation hydrodynamic models of winds and coronae above accretion disks in low-mass X-ray binaries. The numerical method combines adaptive mesh refinement for the hydrodynamics with combined ray tracking/flux-limited diffusion for the radiation. The results of the models are compared with …
Tomography/Power Spectrum Techniques for Removal of Fixed Pattern Noise from Hubble Space Telescope Spectra
Smith, Andrew M.; Bruhweiler, Frederick C.; Lyu, Cheng-Hsuan
We have developed tomography/power spectrum algorithms to differentiate the intrinsic stellar spectrum from the pronounced fluctuations in the spectrum counts due to photocathode granularity and diode-to-diode gain variations. We have presented the results of four typical high signal-to-noise (S/N) and high-resolution data sets, obtained from the …
Hubble Space Telescope Imaging of the Wind-blown Lobe NGC 6165
O'Neil, Earl J., Jr.; Scowen, Paul; Lynds, C. Roger +3 more
We have used the Hubble Space Telescope wide field/planetary camera to study the structure of the bipolar nebular NGC 6164/6165. Our study concentrates on the structure of a number of small clumps of material embedded within the southern lobe of the system (NGC 6165). These knots have a cometary appearance, with bright surfaces facing the central …
The Faint Limit of the Hubble Space Telescope Faint Object Spectrograph and Rejection of the Cosmic-Ray Background
Tytler, David; Davis, Christopher
The faintest object which can be observed with the Hubble Space Telescope (HST) Faint Object Spectrograph (FOS) is set by the detector cosmic-ray background and not by object flux. We use data from Beaver and Lyons to show that 48% of the background counts are from cosmic rays which each generate a near instantaneous burst of two or more counts. S…