Search Publications
Detection of Surface Brightness Fluctuations in NGC 4373 Using the Hubble Space Telescope
Casertano, Stefano; Ballester, Gilda E.; Dressler, Alan +16 more
Surface brightness fluctuations (SBF) have been detected for three elliptical galaxies--NGC 3379 in the Leo group, NGC 4406 in the Virgo cluster, and NGC 4373 in the Hydra-Centaurus supercluster--using marginally sampled, deep images taken with the Planetary Camera of the WFPC2 instrument on the Hubble Space Telescope (HST). The power spectrum of …
A Photometric Investigation of the GRB 970228 Afterglow and the Associated Nebulosity
Castander, Francisco J.; Lamb, Donald Q.
We carefully analyze the WFPC2 and STIS images of GRB 970228. We measure magnitudes for the GRB 970228 point-source component in the WFPC2 images of (V=26.20+0.14-0.13, Ic=23.94+0.10-0.09) and (V=26.52+0.16-0.18, Ic=24.31+0.15-0.11) on Mar…
The Radio-Optical Jet in NGC 3862 from Parsec to Subkiloparsec Scales
Venturi, T.; O'Dea, C. P.; Giovannini, G. +4 more
We have observed the radio source in NGC 3862 (3C 264) simultaneously with the European VLBI network and the MERLIN arrays, obtaining detailed images of its radio structure from parsec to subkiloparsec scales. 3C 264 shows a one-sided jet with evident variations in its morphological properties with distance. We have analyzed Hubble Space Telescope…
NICMOS Observations of the Pre-Main-Sequence Planetary Debris System HD 98800
Schneider, Glenn; Hines, Dean C.; Low, Frank J.
Spectral energy distributions (SEDs) from 0.4 to 4.7 µm are presented for the two principal stellar components of HD 98800, A and B. The third major component, an extensive planetary debris system (PDS), emits greater than 20% of the luminosity of star B in a blackbody SED at 164+/-5 K extending from mid-IR to millimeter wavelengths. At 0.95…
Far-Ultraviolet Space Telescope Imaging Spectrograph Spectra of the White Dwarf REJ 1032+532. II. Stellar Spectrum
Green, E. M.; Barstow, M. A.; Bruhweiler, F. C. +2 more
We discuss the Hubble Space Telescope Space Telescope Imaging Spectrograph UV echelle spectrum of the hot DA white dwarf REJ 1032+532. The interstellar data from this spectrum are presented by Holberg and coworkers. In this paper we discuss a number of strong photospheric features due to C, N, and Si that are present in the REJ 1032+532 spectrum. …
Probable Detection of a Bright Infrared Coronal Emission Line of Si IX near 3.93 Microns
Lin, H.; Mann, I.; Kuhn, J. R. +7 more
We report here the probable detection of an emission line of Si IX that was observed from an open C130 aircraft over the Pacific Ocean during the 1998 total solar eclipse. Although the IR data themselves are inconclusive because of the uncertainty in the precise central wavelengths of the narrowband filters during the eclipse, the consistency of t…
Hubble Space Telescope/Faint Object Spectrograph Spectroscopy of Spatially Resolved Narrow-Line Regions in the Seyfert 2 Galaxies NGC 2110 and NGC 5929
Simpson, Chris; Mulchaey, John S.; Ferruit, Pierre +3 more
We present the results of UV and optical Hubble Space Telescope/Faint Object Spectrograph spectroscopy of bright, extranuclear regions of line emission in the Seyfert galaxies NGC 2110 and NGC 5929. We have obtained spectra of the brightest region of the ``nuclear jet'' of NGC 2110 (75 pc from the nucleus) and of the southwest emission-line cloud …
Tomographic Separation of Composite Spectra. VI. The Physical Properties of the Massive Close Binary HD 152248
Gies, Douglas R.; Penny, Laura R.; Bagnuolo, William G., Jr.
We present the results of a Doppler tomographic reconstruction of the UV spectra of the double-lined O binary HD 152248 based on observations made with IUE. We used cross-correlation methods to obtain radial velocities, confirm the orbital elements, estimate the UV flux ratio, and determine projected rotational velocities. The individual component…
X-Ray Observations of the Seyfert Galaxy LB 1727 (1H 0419-577)
Nandra, K.; Turner, T. J.; Kraemer, S. B. +6 more
We discuss the properties of the Seyfert 1.5 galaxy LB 1727, also known as 1H 0419-577, from X-ray observations obtained by ASCA and ROSAT, along with optical observations from earlier epochs. The source flux was F2-10~=10-11 ergs cm-2 s-1 during the ASCA observations that were carried out during 1996 Ju…
No Increase of the Red Giant Branch Tip Luminosity toward the Center of M31
Meynet, G.; Jablonka, P.; Sarajedini, A. +3 more
We present observations with the Hubble Space Telescope Wide-Field Planetary Camera 2 of three fields centered on super-metal-rich globular clusters in the bulge of M31. Our (I, V-I) color-magnitude diagrams reach as faint as I~26.5 mag and clearly reveal the magnitude of the first-ascent red giant branch (RGB) tip. We find that the apparent I mag…